WO2007060865A1

WO2007060865A1 - Adjustable valve device, and engine device and vehicle using the same

Info

Publication number: WO2007060865A1
Application number: PCT/JP2006/322722
Authority: WO
Inventors: Minoru Yamamoto; Yoshitaka Nagai
Original assignee: Yamaha Hatsudoki Kabushiki Kaisha
Priority date: 2005-11-28
Filing date: 2006-11-15
Publication date: 2007-05-31
Also published as: EP1956197A1; BRPI0618802A2; US20090114175A1; CN101316986A; JP2007146740A

Abstract

In a low rotation mode, a centrifugal force applied to the weight is small and weight rotation is limited. Accordingly, a lock pin is not engaged with a lock pin engaging hole of a floating cam unit and the floating cam unit turns free around a cam fixing shaft. In a high rotation mode, the centrifugal force applied to the weight is large and the weight turns around a rotation shaft. Accordingly, the tip end of the lock pin is engaged with the lock pin engaging hole of the floating cam unit. Thus, during the high rotation, the floating cam unit is fixed by the lock pin in the rotation direction of the adjustable valve device.

Description

Specification

Variable valve operating apparatus, and engine apparatus and vehicle including the same

Technical field

TECHNICAL FIELD [0001] The present invention relates to a variable valve gear that drives a valve of an engine, an engine device including the same, and a vehicle.

Background art

Conventionally, various variable valve mechanisms for controlling intake and exhaust have been developed for the purpose of improving fuel consumption, reducing harmful substances in exhaust gas, and increasing output in a specific rotation range.

[0003] In order to increase the efficiency of intake and exhaust, it is preferable to switch the intake air amount optimally at low engine speed, high engine speed, and high engine speed.

[0004] Generally, the space occupied by an engine in a motorcycle is smaller than that of a four-wheeled vehicle or the like. There is also a demand for cost reduction of motorcycles. As a result, there is a need for a more compact variable noble mechanism for motorcycles.

[0005] Patent Document 1 proposes an engine valve operating device that switches between a low speed cam and a high speed cam with a simple and compact structure. In this valve operating apparatus, a low speed cam is fixed to the cam shaft, and a high speed cam is provided in parallel with the low speed cam so as to be relatively displaceable on the cam shaft. A control shaft is provided in the cam shaft so as to be reciprocally movable in the axial direction. As the control shaft moves in the axial direction, the high-speed cam protrudes in the direction perpendicular to the cam shaft, and the low-speed cam and high-speed cam are switched.

Patent Document 1: Japanese Patent Application Laid-Open No. 09-256827

Disclosure of the invention

Problems to be solved by the invention

[0006] In the valve operating device of Patent Document 1, switching from a low speed cam to a high speed cam is performed by a hydraulic actuator. Specifically, a control lever is provided so as to be interlocked with the control shaft, and the control lever biased by the spring is moved by the hydraulic actuator. As a result, the control axis moves in the axial direction, and the cam force for low speed is switched to the cam for high speed. [0007] In order to move the control lever against the reaction force applied to the high-speed cam and the reaction force applied to the high-speed cam while the spring biasing force and valve force are applied, large hydraulic pressure is required. Become. Therefore, an oil pump that supplies oil to the hydraulic actuator is required to be larger and more expensive. As a result, the production cost increases and miniaturization of the vehicle is hindered.

An object of the present invention is to provide a variable valve operating apparatus that can switch a cam optimally according to the rotational speed of an engine, and an engine apparatus and vehicle including the same, in a small size and at low cost.

Means for solving the problem

[0009] (1) A variable valve operating apparatus according to one aspect of the present invention is a variable valve operating apparatus for driving a valve of an engine, and includes a rotary shaft that is rotatably provided in conjunction with the rotation of the engine. A first force member provided to rotate together with the rotating shaft and acting to open and close the valve; and a first force member provided to be rotatable relative to the rotating shaft and acting to open and close the valve.

2 cam members, and a first state in which the second cam member is rotatable with respect to the rotating shaft and a second state in which the second cam member is locked to the rotating shaft A locking member, a biasing member that generates a biasing force that shifts the locking member to the first state, and a locking member that resists the biasing force of the biasing member due to the centrifugal force associated with the rotation of the rotating shaft. And a drive member that operates to shift to the state of 2. When the locking member is in the first state, the first force member acts to open and close the valve, and the locking member is In this state, the second cam member acts to open and close the valve.

In the variable valve operating apparatus, the rotation shaft rotates in conjunction with the rotation of the engine. The first cam member rotates as the rotating shaft rotates. The second cam member is in a state of being rotatable with respect to the rotating shaft when the locking member is in the first state, and is locked with the rotating shaft when the locking member is in the second state. It becomes. The locking member switches to the first state or the second state according to the rotation speed of the rotating shaft.

[0011] When the rotational speed of the rotating shaft is low, the locking member shifts to the first state by the biasing force generated by the biasing member. Accordingly, the second cam member can be rotated with respect to the rotation shaft by the locking member. Therefore, the second cam member rotates as the rotating shaft rotates. No state. In this case, the first cam member acts to open and close the valve.

On the other hand, when the rotational speed of the rotating shaft is high, the locking member shifts to the second state against the urging force by the urging member due to the centrifugal force applied to the driving member. As a result, the second force member is locked to the rotating shaft. Therefore, the second cam member is in a state of rotating as the rotating shaft rotates. In this case, the second cam member acts to open and close the valve.

[0013] Thus, the state in which the first cam member acts on the valve and the state in which the second cam member acts on the valve are switched according to the rotational speed of the engine. As a result, the first cam member and the second cam member are formed into optimal shapes when the engine is running at low speed and high speed, respectively, thereby improving fuel efficiency during normal driving (medium / low speed driving) and exhaust gas. In addition to reducing harmful substances in the gas, it is possible to achieve high output during high-speed driving.

[0014] In addition, since the first cam member and the second cam member are switched using the centrifugal force generated by the rotation of the rotating shaft, a drive source by a hydraulic system is unnecessary. Therefore, a small and low-cost variable valve operating device is realized.

[0015] (2) The drive member is provided so as to be rotatable to the first position force and the second position by a centrifugal force accompanying the rotation of the rotation shaft, and the locking member is provided with the first position force of the drive member. The urging member is provided so as to be movable in one direction along the rotation axis as it rotates to the position, and the urging member applies an urging force to the driving member so that the driving member is directed toward the first position. The stop member may be in a first state when the drive member is in the first position, and may be in a second state when the drive member is in the second position.

[0016] In this case, the urging force by the urging member acts so that the driving member is directed toward the first position. The centrifugal force accompanying the rotation of the rotating shaft acts so that the drive member rotates to the first position force and the second position.

[0017] When the rotational speed of the rotating shaft is low, the urging force applied to the drive member is greater than the centrifugal force, so the drive member is in the first position. Thereby, the locking member is in the first state. Therefore, the second cam member can rotate with respect to the rotation shaft, and the first cam member acts to open and close the valve.

[0018] When the rotational speed of the rotating shaft is high, the centrifugal force applied to the drive member is larger than the biasing force. Therefore, the driving member also rotates the first positional force to the second position. As a result, the locking member moves in one direction along the rotation axis, and switches from the first state to the second state. Therefore, the second cam member rotates together with the rotating shaft, and the second cam member acts to open and close the valve.

As described above, the locking member shifts to the first state or the second state depending on the magnitude of the centrifugal force applied to the driving member. Thereby, the first cam member and the second cam member can be switched with a simple configuration.

(3) The locking member has a locking portion, the second cam member has a locked portion locked by the locking portion of the locking member, and the locking member is the first The locking portion may release the locked portion force when the locking member is in this state, and the locking portion may lock the locked portion when the locking member is in the second state.

[0021] When the rotational speed of the rotating shaft is low, the locking portion of the locking member is disengaged from the locked portion of the second cam member. As a result, the second cam member can rotate with respect to the rotation shaft. When the rotation speed of the rotating shaft is high, the locking portion of the locking member locks the locked portion of the second cam member. Thereby, the second cam member is fixed with respect to the rotation shaft. In this manner, the first cam member and the second cam member can be switched with a simple configuration.

[0022] (4) The locking member includes a rod-shaped member, the locking portion is an end of the rod-shaped member, and the locked portion of the second cam member can be fitted to the end of the rod-shaped member. Even the hole.

[0023] When the rotational speed of the rotating shaft is low, the end of the rod-shaped member is disengaged from the hole of the second cam member. As a result, the second cam member can rotate with respect to the rotation shaft. When the rotational speed of the rotary shaft is high, the end of the rod-shaped member is inserted into the hole of the second cam member. Thereby, the second cam member is fixed with respect to the rotation shaft. Thus, the first cam member and the second cam member can be switched with a simple configuration.

[0024] (5) The locking member is a plurality of rod-shaped members, and the locked portion of the second cam member is a plurality of holes into which end portions of the plurality of rod-shaped members can be respectively fitted. The rod-shaped members may be arranged at mutually asymmetric positions with respect to the center of the rotation axis.

In this case, since the plurality of rod-like members are respectively inserted into the corresponding plurality of holes, the second cam member is securely fixed to the rotation shaft. In addition, since the plurality of bar-shaped members are arranged at positions asymmetric with respect to the center of the rotation axis, each bar-shaped member is moved to it. It is securely inserted into the corresponding hole.

[0026] (6) The variable valve operating apparatus may further include a movement preventing member that prevents movement of the locking member when the locking member is in at least one of the first state and the second state.

[0027] In this case, since the locking member is securely fixed in the first state or the second state, it is possible to prevent the locking member from becoming unstable due to the reaction force of the valve.

[0028] Further, a force that causes the locking member to shift to the first state due to the biasing force generated by the biasing member, and a force that causes the locking member to shift to the second state due to the centrifugal force applied to the driving member. It is possible to prevent the locking member from becoming unstable between the first state and the second state in a balanced state. As a result, switching between the first cam member and the second cam member is performed stably, and the opening and closing of the knob can be prevented from becoming unstable.

[0029] (7) The locking member has at least one groove, and the movement preventing member is a fit that can be fitted into the groove when the locking member is in at least one of the first state and the second state. It may have a joint.

[0030] In this case, when the locking member is in at least one of the first state and the second state, the fitting portion of the movement preventing member is fitted into the groove portion of the locking member. As a result, the locking member is sufficiently fixed in the first state or the second state, so that it is possible to reliably prevent the locking member from becoming unstable due to the reaction force of the valve.

[0031] Further, the urging force generated by the urging member causes the force to shift the locking member to the first state, and the force causes the driving member to shift the locking member to the second state by the centrifugal force associated with the rotation. It is possible to sufficiently prevent the locking member from becoming unstable between the first state and the second state in a state where the two are balanced.

[0032] (8) At least one of the locking member when the locking member transitions from the first state to the second state and when the locking member transitions to the second state force first state The groove portion and the fitting portion may be formed so that the fitting portion of the movement preventing member can be withdrawn from one groove portion.

[0033] In this case, when the locking member is in the first state or the second state, the fitting portion of the movement preventing member is fitted into the groove portion of the locking member, and the locking member is in the first state force. When moving to the second state or when the second state force is moved to the first state, the movement blocking member is fitted. The part is withdrawn from the groove of the locking member. Thus, when the locking member is in the first state or the second state, it is possible to prevent the locking member from becoming unstable due to the reaction force of the valve, and the first state force second state Transition to the second state force or transition to the first state is performed stably.

(9) The variable valve operating apparatus is interlocked with the rotation of the first transmission member that moves the valve up and down by swinging in conjunction with the rotation of the first cam member, and the rotation of the second cam member. And a second transmission member that swings the first transmission member.

[0035] In this case, the first transmission member swings as the first cam member rotates as the rotation shaft rotates. Thereby, the valve moves up and down.

[0036] Further, in a state where the second cam member is locked to the rotation shaft, the second transmission member swings as the second cam member rotates as the rotation shaft rotates. Thereby, the first transmission member swings and the bubble moves up and down.

[0037] Thus, when the first cam member and the second cam member rotate, the vertical movement of the valve is performed by the swing of the first transmission member. This makes it possible to reduce the size of the valve and prevent the load from being applied to the valve as compared with the case where the first transmission member and the second transmission member individually move the valve up and down. it can.

(10) The first cam member acts to open the valve with the first lift amount in the first state, and

The second cam member may act so as to open the valve with a second lift amount larger than the first lift amount in the second state.

[0039] Here, when the rotation speed of the rotating shaft is low, the first cam member rotates as the rotating shaft rotates. Since the second cam member can rotate with respect to the rotation shaft, it does not rotate with the rotation of the rotation shaft. Thereby, the first cam member acts to open the valve with the first lift amount.

[0040] When the rotation speed of the rotating shaft is high, the first cam member rotates as the rotating shaft rotates, and the second cam member rotates while being locked to the rotating shaft. In this case, the first force member acts to open the valve with the first lift amount, whereas the second cam member operates the valve with the second lift amount that is larger than the first lift amount. Acts to open. As a result, the valve moves up and down by the second lift amount. [0041] In this manner, the lift amount of the valve is switched between the first lift amount and the second lift amount according to the rotational speed of the engine. As a result, fuel efficiency during normal driving can be improved, harmful substances in exhaust gas can be reduced, and high output during high-speed driving can be realized.

[0042] (11) The first cam member acts to open the valve at the first operating angle in the first state, and the second cam member is larger than the first operating angle in the second state It may act to open the valve at the second operating angle.

Here, when the rotational speed of the rotating shaft is low, the first cam member acts to open the valve at the first operating angle.

[0044] When the rotational speed of the rotating shaft is high, the second cam member is larger than the first operating angle.

Acts to open the valve at a working angle of 2.

[0045] Thus, the valve operating angle is switched between the first operating angle and the second operating angle in accordance with the rotational speed of the engine. As a result, fuel efficiency during normal driving can be improved, harmful substances in exhaust gas can be reduced, and high output during high-speed driving can be realized.

[0046] (12) The valve may be an intake valve. In this case, the state in which the first cam member acts on the intake valve and the state in which the second cam member acts on the intake valve are switched according to the rotational speed of the engine. Thereby, the intake amount or the intake timing is adjusted by forming the first cam member and the second cam member in optimum shapes when the engine is running at low speed and at high speed, respectively. As a result, fuel costs during normal driving can be improved, harmful substances in the exhaust gas can be reduced, and high output during high-speed driving can be realized.

[0047] (13) An engine device according to another aspect of the present invention includes an engine having a valve and a variable valve operating device for driving the engine valve, the variable valve operating device rotating the engine. A rotary shaft provided rotatably in conjunction with the rotary shaft, a first cam member provided so as to rotate together with the rotary shaft and acting to open and close the valve, and provided so as to be rotatable relative to the rotary shaft. A second cam member that acts to open and close the first cam member, a first state in which the second cam member is rotatable with respect to the rotating shaft, and a second state in which the second cam member is locked to the rotating shaft. A locking member that can be shifted to the first state, a biasing member that generates a biasing force that shifts the locking member to the first state, and a biasing member that is biased by the centrifugal force associated with the rotation of the rotating shaft. A drive member that operates to move the locking member to the second state against the force, and when the locking member is in the first state, the first cam member acts to open and close the valve. However, when the locking member is in the second state, the second cam member acts to open and close the valve.

[0048] In the engine device, the valve of the engine is driven by the variable valve operating device.

[0049] In the variable valve operating apparatus, the rotating shaft rotates in conjunction with the rotation of the engine. The first cam member rotates as the rotating shaft rotates. The second cam member is rotatable with respect to the rotating shaft when the locking member is in the first state, and is locked with the rotating shaft when the locking member is in the second state. It becomes a state. The locking member switches to the first state or the second state according to the rotation speed of the rotating shaft.

[0050] When the rotational speed of the rotating shaft is low, the locking member shifts to the first state by the biasing force generated by the biasing member. Accordingly, the second cam member can be rotated with respect to the rotation shaft by the locking member. Therefore, the second cam member does not rotate with the rotation of the rotating shaft. In this case, the first cam member acts to open and close the valve.

On the other hand, when the rotation speed of the rotating shaft is high, the locking member moves to the second state against the urging force by the urging member due to the centrifugal force applied to the drive member. As a result, the second force member is locked to the rotating shaft. Therefore, the second cam member is in a state of rotating as the rotating shaft rotates. In this case, the second cam member acts to open and close the valve.

[0052] Thus, the state in which the first cam member acts on the valve and the state in which the second cam member acts on the valve are switched according to the rotational speed of the engine. As a result, the first cam member and the second cam member are formed into optimal shapes when the engine is running at low and high speeds, respectively, thereby improving fuel efficiency during normal driving and toxic substances in the exhaust gas. As well as higher output during high-speed driving.

[0053] Further, the first cam member and the second cam member are separated by utilizing the centrifugal force generated by the rotation of the rotation shaft. Since it is switched, a drive source by a hydraulic system is unnecessary. Therefore, a small and low-cost variable valve operating device is realized.

(14) A vehicle according to still another aspect of the present invention includes an engine device, a drive wheel, and a transmission mechanism that transmits power generated by the engine device to the drive wheel. The engine device includes a valve. And a variable valve device for driving a valve of the engine, and the variable valve device is configured to rotate together with the rotation shaft, and a rotation shaft provided to rotate in conjunction with the rotation of the engine. A first cam member that operates to open and close the valve, a second cam member that is rotatably provided to the rotating shaft and operates to open and close the valve, and a second cam member A locking member provided so as to be able to shift between a first state in which the shaft is rotatable with respect to the rotation shaft and a second state in which the second cam member is locked to the rotation shaft, and the locking member is A biasing member that generates a biasing force to shift to the state of And a drive member that operates to shift the locking member to the second state against the urging force of the urging member due to the centrifugal force accompanying the rotation of the rotating shaft, and the locking member is in the first state. In some cases, the first cam member acts to open and close the valve, and when the locking member is in the second state, the second cam member acts to open and close the valve.

[0055] In the vehicle, the power generated by the engine device is transmitted to the drive wheels by the transmission mechanism, and the drive wheels are driven. Here, in the engine device, the valve of the engine is driven by the variable valve operating device.

[0056] In this case, in the variable valve operating apparatus, the state in which the first cam member acts on the valve and the state in which the second cam member cover acts on the valve are switched according to the rotational speed of the engine. . As a result, the first cam member and the second cam member are formed into optimal shapes when the engine is running at low and high speeds, respectively, thereby improving fuel efficiency during normal driving and toxic substances in the exhaust gas. As well as high output during high-speed driving.

[0057] In addition, since the first cam member and the second cam member are switched using the centrifugal force generated by the rotation of the rotating shaft, a drive source by a hydraulic system is unnecessary. Therefore, a small and low-cost variable valve operating device is realized.

The invention's effect [0058] According to the present invention, the state in which the first cam member acts on the valve and the state in which the second cam member CAS valve acts on the valve are switched according to the rotational speed of the engine. As a result, the first cam member and the second cam member are formed into optimal shapes when the engine is running at low and high speeds, respectively, thereby improving fuel efficiency during normal driving and toxic substances in the exhaust gas. As well as high output during high-speed driving. Further, since the first cam member and the second cam member are switched using the centrifugal force generated by the rotation of the rotating shaft, a drive source by a hydraulic system is not necessary. Therefore, a small and low-cost variable valve operating device is realized.

Brief Description of Drawings

FIG. 1 is a schematic diagram of a motorcycle according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the outline of a variable valve operating apparatus according to an embodiment of the present invention.

FIG. 3 is an assembled perspective view for explaining the structure of the variable valve operating apparatus.

FIG. 4 is an assembled perspective view for explaining the structure of the variable valve operating apparatus.

FIG. 5 is an assembled perspective view for explaining the structure of the variable valve operating apparatus.

FIG. 6 is an XZ plane sectional view of the lock plate housing member in a state where the lock plate and the spring are inserted.

FIG. 7 is a cross-sectional view showing a state of the variable valve operating apparatus during low rotation.

FIG. 8 is a cross-sectional view showing a state of the variable valve operating apparatus during high rotation.

[FIG. 9] FIG. 9 is a diagram for explaining the details of the operation of the lock plate and the lock pin of FIG. 7 and FIG.

FIG. 10 is a cross-sectional view showing a state in which the variable valve gear is attached to the engine.

FIG. 11 is a top view showing the arrangement of the variable valve operating device, intake high cam rocker arm, intake low cam rocker arm and exhaust cam rocker arm of FIG.

FIG. 12 is a cross-sectional view taken along line RR of the cylinder head of FIG.

FIG. 13 is a diagram showing displacement amounts of the intake valve and the exhaust valve shown in FIG.

FIG. 14 is a view showing a modification of the variable valve operating apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION [0060] Hereinafter, a variable valve operating apparatus according to an embodiment of the present invention, an engine apparatus including the same, and a vehicle will be described. In the present embodiment, a small motorcycle will be described as a vehicle.

[0061] (1) Vehicle configuration

[0062] This motorcycle 100 is provided with a head pipe 3 at the front end of the main body frame 6. A front fork 2 is provided on the head pipe 3 so as to be swingable in the left-right direction. The front wheel 1 is rotatably supported at the lower end of the front fork 2. A handle 4 is attached to the upper end of the head pipe 3.

[0063] An engine 7 is held at the center of the main body frame 6. A fuel tank 8 is provided above the engine 7, and a seat 9 is provided behind the fuel tank 8.

[0064] A rear arm 10 is connected to the main body frame 6 so as to extend rearward of the engine 7. The rear arm 10 rotatably holds the rear wheel 11 and the rear wheel driven sprocket 12. An exhaust pipe 13 is connected to the engine 7. A muffler 14 is attached to the rear end of the exhaust pipe 13.

A rear wheel drive sprocket 15 is attached to the drive shaft 26 of the engine 7. The rear-wheel drive sprocket 15 is connected to the rear-wheel drive socket 12 of the rear wheel 11 via a chain 16.

[0066] The engine 7 is provided with a variable valve gear. Hereinafter, the variable valve operating apparatus according to the present embodiment will be described.

[0067] (2) Overview of variable valve gear

FIG. 2 is a diagram for explaining the outline of the variable valve operating apparatus according to the embodiment of the present invention. FIG. 2 (a) shows a schematic top view of the variable valve gear provided inside the engine 7, and FIG. 2 (b) shows a schematic side view of the variable valve gear provided inside the engine 7. The

As shown in FIGS. 2 (a) and 2 (b), the variable valve gear 200 is provided in the cylinder head 7 S of the engine 7. The variable valve operating apparatus 200 includes a cam driven sprocket 220, an intake high cam 237, an intake low cam 241 and an exhaust cam 242. [0069] As the piston 21 reciprocates in the cylinder 20, the crankshaft 23 rotates, and the cam drive sprocket 24 provided on the crankshaft 23 rotates.

The rotational force of the cam drive sprocket 24 is transmitted to the cam driven sprocket 220 of the variable valve operating apparatus 200 via the chain 25. Thereby, the variable valve apparatus 200 rotates.

In variable valve operating apparatus 200, switching between intake air, icam 237 and intake low cam 241 is performed in accordance with the rotational speed of engine 7 and changes in the rotational speed (increase and decrease in rotational speed). As a result, the lift amount of an intake valve, which will be described later, changes, and the intake amount to the cylinder 20 changes.

[0072] (3) Configuration of variable valve operating device

Details of the configuration of the variable valve apparatus 200 will be described. 3 to 5 are assembled perspective views for explaining the structure of the variable valve operating apparatus 200. FIG. In FIGS. 3 to 5, as indicated by arrows X, Υ, and Z, the three directions orthogonal to each other are defined as the X direction, the Y direction, and the Z direction.

[0073] The variable valve device 200 is roughly divided into a lock pin holding mechanism 210 (see Fig. 3), a cam driven sprocket 220 (see Fig. 4), a lock pin locking mechanism 230 (see Fig. 4), and a floating cam. Part 23 5 (see Fig. 5) and camshaft 240 (see Fig. 5) forces are also configured! RU

FIG. 3 shows an assembled perspective view of the lock pin holding mechanism 210. As shown in FIG. 3, the lock pin holding mechanism 210 has a support member 211 parallel to the XZ plane. A through hole 211G is formed at the center of the support member 211.

[0075] On one side of the upper end portion and the lower end portion of the support member 211, projection pieces 21 la and 21 lb bent so as to extend in the Y direction are formed. Between the protruding piece 21 la and the protruding piece 21 lb, a spring holding piece 212a bent in a U-shape and a protruding piece 21 lc extending in the X direction are formed on one surface side of the support member 211. .

On the other side of the upper end portion and the lower end portion of the support member 211, projection pieces 21 Id and 21 le bent so as to extend in the Y direction are formed. Between the projecting piece 21 Id and the projecting piece 21 le, there are formed a projecting piece 21 If extending in the X direction and a spring holding piece 212 b bent in a U shape on one surface side of the support member 211. . [0077] Through holes 211A to 211F are formed in the projecting pieces 211a to 211f, and through holes 212A and 212B are formed in the spring holding pieces 212a and 212b, respectively.

[0078] At the center of the upper end portion and the center of the lower end portion of the support member 211, concave notches 211H, 2

1 II is formed.

[0079] The weight 213 includes a weight body 213a, a plate-like extension 213d, two cylindrical portions 213e, and two hook portions 213f. The weight main body 213a has a substantially rectangular parallelepiped shape extending in the X direction.

[0080] The extension 213d is formed to extend in the Y direction from the upper surface of the weight body 213a. The two cylindrical portions 213e are respectively formed at both ends of the extension portion 213d in the X direction.

[0081] The two hook portions 213f extend from the central portion of the extension portion 213d in the X direction so as to incline to the lower side of the extension portion 213d. The tips of the two hook portions 213f are curved in a partial cylindrical shape.

[0082] Lock pins 214 extending in the Y direction are attached to the two hook portions 213f. Near one end of the lock pin 214, a support pin 214t extending in the X direction is formed. By attaching the support pin 214t to the hook portion 213f, the lock pin 214 is rotatably held by the weight 213. A part of the lock pin 214 can come into contact with the weight body 213.

[0083] On the outer peripheral surface in the vicinity of the other end of the lock pin 214, an annular groove 214a and a groove 214b are formed in parallel.

A rotating shaft 215 is inserted into the cylindrical portion 213e of the weight 213. Thereby, the rotating shaft 215 holds the weight 213 in a rotatable manner. In this state, both ends of the rotation 215 are inserted into the through holes 211A and 211D of the support member 211. Thereby, the weight 213 is rotatably held on the support member 211. The lock pin 214 is disposed so as to pass through the notch 211H of the support member 211.

The weight 216 has the same structure as the weight 213. When the lock pin holding mechanism 210 is assembled, the weight 216 is disposed so as to face the weight 213.

[0086] Fig. 3 [Koo! Way, body 216 of way 216, way 216a, extension 216d, two cylindrical 216e, and two hooks 216f are way body 213a, way 213a, extension 213d, 2 This corresponds to the cylindrical portion 213e and the two hook portions 213f.

The lock pin 217 has the same structure as the lock pin 214. The groove portions 217a and 217b of the lock pin 217 correspond to the groove portions 214a and 214b. The support pin 217t corresponds to the support pin 214t.

[0088] The rotating shaft 218 is inserted into the cylindrical portion 216e of the weight 216. Thereby, the rotating shaft 218 holds the weight 216 in a rotatable manner. In this state, both ends of the rotating shaft 218 are inserted into the through holes 211B and 211E of the support member 211. Thereby, the weight 216 is rotatably held on the support member 211. Further, the lock pin 217 is disposed so as to pass through the notch 21 II of the support member 211.

The lock pins 214 and 217 are arranged so as to be perpendicular to the support member 211. The distance between the through hole 211G of the support member 211 and the lock pin 214 is smaller than the distance between the through hole 211G and the lock pin 217.

[0090] Screws 219 are inserted into the two through holes 211C and 211F of the two projecting pieces 211c and 211f of the support member 211, respectively.

FIG. 4 is an assembly perspective view of the lock pin holding mechanism 210, the cam driven sprocket 220, and the lock pin locking mechanism 230. The cam driven sprocket 220 is arranged so as to be parallel to the XZ plane, and the lock pin locking mechanism 230 is arranged so that its axis J is parallel to the Y direction.

Here, in the lock pin holding mechanism 210, one end of the spring S1 is locked in the through hole of the protruding portion (not shown) of the weight 213, and the other end is locked in the through hole 212B of the spring holding piece 212b. It has been. One end of the spring S2 is locked in a through hole of a protruding portion (not shown) of the weight 216, and the other end is locked in a through hole 212A of the spring holding piece 212a.

[0093] The cam driven sprocket 220 has through holes 220a to 220e. The through hole 220a formed at the center of the cam dribbling procket 220 has a larger diameter than the other through holes 220b to 220e.

The through holes 220a, 220b, and 220c are arranged on the same straight line parallel to the Z direction, and the through hole 220b and the through hole 220c have the same diameter. The distance between the through hole 220a and the through hole 22 Ob is smaller than the distance between the through hole 220a and the through hole 220c. In addition, The through hole 220d and the through hole 220e are formed symmetrically with respect to the through hole 220a and have the same diameter.

The lock pin locking mechanism 230 is formed of a cylindrical rotating shaft 231 and a disk-shaped lock plate storage member 232.

The lock pin locking mechanism 230 has through holes 230H, 230b, and 230c. The through hole 230H is formed in the shaft center J of the lock pin locking mechanism 230. That is, the through-hole 230H is formed from the center of the end surface of the rotating shaft 231 to the center of the end surface of the lock plate housing member 232. The through holes 230H, 230b, and 230c are arranged on the same straight line parallel to the Z direction, and the through hole 230b and the through hole 230c have the same diameter. Note that the distance between the through hole 230H and the through hole 230b is shorter than the distance between the through hole 230H and the through hole 230c.

Also, screw end holes 230d and 230e are formed on the end surface of the rotating shaft 231 of the lock pin locking mechanism 230. The screw insect accumulation holes 230d and 230e are formed at mutually symmetrical positions with the through hole 230H as the center and have the same diameter. The screw screw holes 230 d and 230 e are threaded. Further, a step portion 23 la is formed on the outer peripheral surface of the rotating shaft 231.

[0098] A slit-like lock plate insertion port 232A and a substantially circular spring insertion port 232B are formed on the outer peripheral surface of the lock plate storage member 232 of the lock pin locking mechanism 230. The lock plate insertion port 232A communicates with the lock plate storage space 232b formed in the lock plate storage member 232 (FIG. 6 described later), and the spring 揷 inlet 232B is the spring storage space formed in the lock plate storage member 232. It communicates with 232c (Figure 6 below).

[0099] The plate-shaped lock plate 233 is inserted into the lock plate storage space 232b (FIG. 6) in the lock plate storage member 232 from the lock plate insertion port 232A. The spring 234 is inserted from the spring insertion port 232B into the spring storage space 232c (FIG. 6) in the lock plate storage member 232.

[0100] The lock plate 233 includes a substantially rectangular support plate 233a, a long lock pin engagement portion 233b, and a long lock pin engagement portion 233c. The lock pin engaging portion 233b extends in one direction along one side of the support plate 233a, and the lock pin engaging portion 233c extends diagonally outward at one corner of the support plate 233a and is parallel to the lock pin engaging portion 233b. It is bent to become. support A through hole 233A is formed at the center of the plate 233a.

[0101] A columnar member 234a is attached to one end of the spring 234 to facilitate attachment to and removal from the lock pin locking mechanism 230.

Here, the arrangement of the lock plate 233 and the spring 234 in the lock plate storage member 232 will be described with reference to FIG.

FIG. 6 shows the lock plate housing member 23 with the lock plate 233 and the spring 234 inserted.

FIG.

As shown in FIG. 6, a pin 233 d is inserted into the through hole 233 A of the lock plate 233. As a result, the lock plate 233 is held so as to be swingable within the lock plate storage space 232b of the lock plate storage member 232.

Further, the spring 234 is inserted into the spring housing space 232 c in the direction of the force 234, and the lower end portion of the spring 234 comes into contact with the upper end portion of the lock pin engaging portion 233 b of the lock plate 233. As a result, the lock plate 233 is biased downward.

[0106] The lower end portion of the lock pin engaging portion 233c of the lock plate 233 is fitted into the groove portion 214a (Fig. 3) or the groove portion 214b (Fig. 3) of the lock pin 214 inserted in the Y direction into the lock plate housing member 232. Is done. The lower end portion of the lock pin engaging portion 233b of the lock plate 233 is fitted into the groove portion 217a (FIG. 3) or the groove portion 217b (FIG. 3) of the lock pin 217 inserted in the Y direction into the lock plate housing member 232.

Accordingly, the movement force in the Y direction of the lock pins 214 and 217 is limited by the lock plate 233.

Details will be described later.

Here, as shown in FIG. 4, the relative positions of the through holes 220d and 220e with respect to the through hole 220a of the cam driven sprocket 220 are the same as the through holes 230H of the lock pin locking mechanism 230. The relative positions of the screw screw holes 230d and 230e as the reference are the same. In addition, the diameter of the through holes 230d and 230e is equal to the diameter of the screw insect holes 220d and 220e!

When assembling the lock pin holding mechanism 210, the cam driven sprocket 220 and the lock pin locking mechanism 230, the position of the through hole 220d of the cam driven sprocket 220 and the through hole 230d of the lock pin locking mechanism 230 The position of the through hole 220e of the cam driven sprocket 220 and the position of the through hole 230e of the lock pin locking mechanism 230. In this state, the screws 219 of the lock pin holding mechanism 210 are screwed together.

Thereby, the lock pin holding mechanism 210 is fixed to one surface of the cam driven sprocket 220, and the lock pin locking mechanism 230 is fixed to the other surface of the cam driven sprocket 220.

[0111] At this time, the lock pin 214 is inserted into the through hole 220b of the cam driven sprocket 220 and the through hole 230b of the lock pin locking mechanism 230, and the lock pin 217 is inserted into the through hole 220c and the lock pin of the cam driven sprocket 220. It is inserted into the through hole 230c of the locking mechanism 230. When the weights 213 and 216 are turned, the lock pin 214 and 217 force S The lock plate storage member 232 side end face force of the lock pin engagement mechanism 230 also protrudes, and the lock pins 214 and 217 are inside the lock pin engagement mechanism 230 The state stored in is switched. Details will be described later.

FIG. 5 shows an assembled perspective view of the structure assembled as shown in FIG. 4 (hereinafter referred to as an assembled structure), the floating cam portion 235 and the camshaft 240. Note that the axis J of the idle power section 235 and the camshaft 240 is arranged to be parallel to the Y direction.

[0113] The idle cam portion 235 is formed of an intake high cam 237 having a lock pin fitting portion 236 and a cam nose 237A. A through hole 235H is formed in the portion of the axis J of the floating cam portion 235. That is, the through hole 235H is formed from the center of the end surface of the lock pin fitting portion 236 to the center of the end surface of the intake high cam 237.

[0114] Lock pin fitting holes 236b and 236c force S are formed in the lock pin fitting portion 236 of the floating cam portion 235. The lock pin fitting holes 236b and 236c and the through hole 235H are arranged on the same straight line parallel to the Z direction, and the lock pin fitting hole 236b and the lock pin fitting hole 236c have the same diameter. The distance between the through hole 235H and the lock pin fitting hole 236b is shorter than the distance between the through hole 235H and the lock pin fitting hole 236c.

[0115] The camshaft 240 includes an intake low cam 241 having a cam nose 241A, an exhaust cam 242 having a cam nose 242A, a stepped portion 243, a cam fixing shaft 244, and a protruding shaft 245.

[0116] The camshaft 240 has a cam fixing shaft 244 extending in the Y direction on one end side in the Y direction, a stepped portion 243, an intake low cam 241 and an exhaust cam 242 in the central portion, and Y on the other end side. It has a protruding shaft 245 extending in the direction. A screw hole 240H is formed at the end of the cam fixing shaft 244. [0117] The length of the cam nose 237A of the intake high cam 237 of the floating cam portion 235 is larger than the length of the cam nose 241A of the intake low cam 241! /.

[0118] At the time of assembling the assembled structure, the floating cam portion 235, and the camshaft 240, the floating cam portion 235 and the camshaft 240 are attached to the lock plate housing member 232 of the assembled structure.

In this case, the cam fixing shaft 244 of the camshaft 240 is inserted into the through hole 235H of the floating cam portion 235 and the through hole 230H (FIG. 4) of the lock pin locking mechanism 230. As a result, the idle power portion 235 is rotatably held by the camshaft 240.

Further, in the through hole 235H (FIG. 5) of the screw hole 240H force lock pin locking mechanism 230 of the cam fixing shaft 244, it opposes the through hole 220a (FIG. 4) of the cam driven sprocket 220. Further, the through hole 220a (FIG. 4) of the cam driven sprocket 220 and the through hole 211G of the lock pin holding mechanism 210 face each other.

[0121] In this state, the screw 250 is screwed into the screw hole 240H of the cam fixing shaft 244 in the through-hole 211G force of the lock pin holding mechanism 210. As a result, the force shaft 240 is fixed to the cam driven sprocket 220. Thereby, the variable valve apparatus 200 is completed.

[0122] It should be noted that the rotation shaft 231 and the lock plate storage member 232 of the lock pin locking mechanism 230 may be formed integrally or individually. In addition, the intake low cam 241, the exhaust cam 242, the stepped portion 243, the cam fixing shaft 244 and the protruding shaft 245 of the camshaft 240 may be integrally formed! / It's okay.

Further, although not shown in FIG. 5, a connecting mechanism between the cam fixing shaft 244 and the through hole 220a (FIG. 4) is provided with a fixing mechanism that restricts the rotation of the cam shaft 240 with respect to the cam driven sprocket 220. May be.

[0124] For example, this fixing mechanism is provided with a protrusion at the tip of the cam fixing shaft 244 of the camshaft 240, and fitted with the protrusion of the cam fixing shaft 244 in the through hole 220a (Fig. 4) of the cam driven sprocket 220. It may be realized by providing a matching groove.

[0125] (4) Operation of variable valve gear

In the variable valve gear 200 having the configuration shown in FIGS. The state is switched accordingly. Next, switching of the state of the variable valve gear 200 will be described. In the following description, the case where the rotational speed of the engine 7 (see FIG. 1 and FIG. 2) is higher than a predetermined value is referred to as high rotation, and the case where the rotation speed is lower than the predetermined value is referred to as low rotation. The rotational speed of the cam fixed shaft 244 is half of the rotational speed of the engine 7. The rotational speed of the cam fixed shaft 244 at the time of switching between low rotation and high rotation is called a threshold value.

First, when the engine 7 is operated, the variable valve apparatus 200 (see FIGS. 3 to 6) rotates. As a result, centrifugal force due to rotation is applied to the weights 213 and 216 of the variable valve apparatus 200 in addition to the biasing force due to the springs SI and S2. The magnitude of the centrifugal force applied to the weights 213 and 216 varies depending on the rotational speed of the variable valve apparatus 200. The state of the variable valve apparatus 200 is switched using the change in the magnitude of the centrifugal force.

FIG. 7 is a cross-sectional view showing the state of the variable valve apparatus 200 during low rotation, and FIG. 8 is a cross-sectional view showing the state of the variable valve apparatus 200 during high rotation.

In FIG. 7 and FIG. 8, as indicated by arrows Y and Z, two directions orthogonal to each other are defined as a Y direction and a Z direction. The direction in which the arrow points is the + direction, and the opposite direction is the one direction.

As shown in FIG. 7, the urging force in the Z direction by the spring S1 is applied to the weight 213, and the centrifugal force in the + Z direction by the rotation of the variable valve apparatus 200 is applied to the weight 213. During low rotation (when the rotational speed of the force fixed shaft 244 is lower than the threshold value), the centrifugal force applied to the weight 213 is small, so that the weight 213 rotates around the rotation shaft 215 by the biasing force of the spring S1. Operation is restricted.

[0130] The lock pin engaging portion 233c of the lock plate 233 is fitted in the groove 214a of the lock pin 214. The lock plate 233 is biased in the Z direction by a spring 234 (see FIGS. 4 and 6). Therefore, the movement of the lock pin 214 in the + Y direction is limited.

Thereby, the lock pin 214 is fixed in a state where the tip thereof is housed in the lock pin locking mechanism 230.

[0132] Similarly, a biasing force in the + Z direction by the spring S2 (Figs. 3 to 5) is applied to the weight 216, and a centrifugal force in the Z direction is applied by the rotation of the variable valve apparatus 200. . At low speed, the centrifugal force applied to the weight 216 is small. Rotation of the weight 216 centering on the is restricted.

[0133] Since the lock pin engaging portion 233b of the lock plate 233 is fitted in the groove portion 217a of the lock pin 217, and the lock plate 233 is urged in the Z direction by the spring 234, the lock pin 217

Movement in the + Y direction is restricted.

Thereby, the lock pin 217 is fixed in a state where the tip thereof is accommodated in the lock pin locking mechanism 230.

In this way, the lock pin fitting holes 236b, 236c [the lock pins 214, 217 of the idle power mug 235 are not fitted, and the idle cam portion 235 rotates around the cam fixing shaft 244.

On the other hand, as shown in FIG. 8, at the time of high rotation (when the rotation speed of the cam fixing shaft 244 exceeds the threshold value), the centrifugal force in the + Z direction applied to the weight 213 Spring S1 The weight 213 is larger than the biasing force in the Z direction, and the weight 213 acts to rotate in the direction of the arrow Ml about the rotation axis 215.

[0137] Along with this, a force to move the lock pin 214 in the + Y direction is applied. As a result, the lock pin engaging portion 233 c of the lock plate 233 is disengaged from the groove portion 214 a of the lock pin 214. As a result, when the position of the lock pin fitting hole 236b of the floating cam portion 235 and the position of the distal end portion of the lock pin 214 are aligned, the one-side force of the lock pin 214 lock pin locking mechanism 230 also protrudes, The cam portion 235 is fitted into the lock pin fitting portion 236b. At this time, the lock pin engaging portion 233 c of the lock plate 233 is fitted into the groove 214 b of the lock pin 214. This restricts the movement of the lock pin 214 in the Y direction. Therefore, the lock pin 214 is fixed in a state of being fitted to the lock pin fitting portion 236b of the floating cam portion 235.

[0138] Similarly, centrifugal force in Z direction applied to weight 216 by spring S2 (Figs. 3-5)

The force becomes greater than the urging force in the + Z direction, and the weight 216 acts to rotate in the direction of the arrow M2 around the rotation axis 218.

[0139] Along with this, a force to move in the + Y direction acts on the lock pin 217. As a result, the lock pin engaging portion 233b of the lock plate 233 is disengaged from the groove portion 217a of the lock pin 217. As a result, when the position of the lock pin fitting hole 236c of the floating cam portion 235 and the position of the tip end portion of the lock pin 217 are aligned, the tip of the lock pin 217 protrudes on one surface of the lock pin locking mechanism 230, and The cam portion 235 is fitted into the lock pin fitting portion 236c. At this time, lock The lock pin engaging portion 233b of the plate 233 is fitted into the groove portion 217b of the lock pin 217. This restricts the movement of the lock pin 214 in the Y direction. Therefore, the lock pin 217 is fixed in a state of being fitted in the lock pin fitting hole 236c of the floating cam portion 235.

In this way, at the time of high rotation, the idle cam portion 235 is fixed with respect to the rotation direction of the variable valve apparatus 200 by the lock pins 214 and 217.

Further, as shown in FIGS. 3 to 5, the lock pin 214 and the lock pin 217, and the lock pin fitting hole 236b and the lock pin fitting hole 236c are different from each other with respect to the cam fixing shaft 244. Have a distance. As a result, the floating cam portion 235 is always fixed at the same phase with respect to the rotating shaft without being fixed in an inverted state.

[0142] Here, in general, when such a switching mechanism using centrifugal force is provided, the centrifugal force applied to the weights 213 and 216 and the springs SI and S2 in the rotational speed region where the engine 7 is provided. A state occurs that balances with the biasing force. If this state continues, the movement of the lock pins 214 and 217 becomes unstable.

Therefore, in the present embodiment, the movement of the lock pins 214 and 217 is restricted by the lock plate 233. Thereby, the movement of the lock pins 214 and 217 is performed stably. The details of the operation are described below.

FIG. 9 is a diagram for explaining the details of the operation of the lock plate 233 and the lock pins 214 and 217 of FIGS. 7 and 8. Fig. 9 (a) shows the state of the lock plate 233 and the lock pins 2 14 and 217 at the time of low rotation (the state shown in Fig. 7). Fig. 9 (c) FIG. 9 (b) shows the state of the lock pins 214 and 217 (the state shown in FIG. 8). FIG. 9 (b) shows the state of the lock plate 233 and the lock on the way to the state of FIG. 9 (a) Indicates the state of pins 214 and 217.

In FIG. 9, the Y direction and the Z direction are defined as in FIGS. 7 and 8. Only the lock pin engagement portion 233c of the lock pin engagement portion 233c and the lock pin engagement portion 233b of the lock plate 233 is shown. The relationship between the lock pin 217 and the lock pin engaging portion 233b is the same as the relationship between the lock pin 214 and the lock pin engaging portion 233c.

[0146] As shown in FIG. 9, the cross sections of the grooves 214a and 214b of the lock pin 214 are formed in a V-shape. ing. The cross section of the lower end portion of the lock pin engaging portion 233c is formed in a tapered shape complementary to the cross sectional shape of the groove portions 214a and 214b.

[0147] When shifting from the low rotation state of Fig. 9 (a) to the high rotation state of Fig. 9 (c), as shown in Fig. 9 (b), the lock pin engaging portion 233c The lower end force of the lock pin 214 is lifted in the + Z direction along the inclined surface of the groove portion 214a of the lock pin 214, and comes off from the groove portion 214a. As a result, the lock pin 214 moves in the + Y direction. The transition from the high rotation state to the low rotation state is performed in the reverse order.

As described above, by restricting the movement of the lock pin 214 by the lock plate 233, the movement force of the lock pin 214 in the + Y direction is reduced when the engine speed is changed from the low state to the high state. If it is not large enough, the lock pin 214 will not move. Specifically, the centrifugal force force in the + Z direction acting on the weight 213 is caused by the spring S1 — when the force increases in the Z direction beyond a certain value (the rotational speed of the cam fixed shaft 244 The lock pin 214 moves when the value becomes higher than the threshold value by a certain value or more.

[0149] Further, when the state force with a high engine speed is shifted to a low state, the lock pin 214 does not move unless the moving force of the lock pin 214 in the + Y direction becomes sufficiently large. Specifically, when the centrifugal force in the + Z direction applied to the weight 213 becomes smaller than a certain value by the spring S1 — the biasing force in the Z direction (the rotational speed of the cam fixed shaft 244 is the threshold value). The lock pin 214 moves when it becomes lower than a certain value.

Accordingly, in a state where the centrifugal force applied to the weights 213 and 216 and the biasing force of the springs SI and S2 are balanced, the movement of the lock pins 214 and 217 is prevented from becoming unstable.

[0151] (5) Attaching the variable valve gear to the engine

FIG. 10 is a cross-sectional view showing a state in which the variable valve apparatus 200 is attached to the engine 7. In FIG. 10, as indicated by arrows X, Υ, and Z, three directions orthogonal to each other are defined as an X direction, a Y direction, and a Z direction.

[0152] As shown in FIG. 10, a space for attaching the variable valve gear 200 is provided in the upper part of the cylinder head 7S.

[0153] Bearings Bl and B2 are attached to the outer periphery of the rotary shaft 231 and the outer periphery of the projecting shaft 245 of the variable valve apparatus 200, respectively. [0154] Inside the cylinder head 7S, one end surface perpendicular to the Y direction of the bearing B1 contacts the internal contact surface BH1 of the cylinder head 7S. Also, one end surface of the bearing B2 perpendicular to the Y direction contacts the internal contact surface BH2 of the cylinder head 7S. A part of the other end surface perpendicular to the Y direction of the bearing B1 is brought into contact with the fixed plate BH3 connected to the cylinder head 7S. As a result, the variable valve apparatus 200 is rotatably fixed inside the cylinder head 7S.

[0155] An intake high cam rocker arm 330, an intake low force murotsu car arm 340, and an exhaust cam rocker arm 350 are provided on the upper part of the variable valve apparatus 200! /. The intake high cam rocker arm 330 is in contact with the intake high cam 237 of the variable valve operating device 200, the intake low force Murotsuker arm 340 is in contact with the intake low cam 241 of the variable valve operating device 200, and the exhaust cam rocker arm 350 is in contact with the variable valve operating device 200. Contact exhaust cam 242.

[0156] A side cover SC is attached to the cylinder head 7S so as to cover the lock pin holding mechanism 210 side of the variable valve apparatus 200. A chain 25 is hung on the cam driven sprocket 220.

[6] (6) Valve drive by variable valve gear

FIG. 11 is a top view showing the arrangement of the variable valve gear 200, the intake high cam rocker arm 330, the intake low cam rocker arm 340, and the exhaust cam rocker arm 350 of FIG. FIG. 12 is a cross-sectional view taken along the line RR of the cylinder head 7S of FIG. 11 and 12, the X direction, the Y direction, and the Z direction are defined as in FIG.

[0158] As shown in Fig. 11, the variable valve gear 200 is mounted in the cylinder head 7S by bearings Bl and B2. The intake high cam rocker arm 330 and the intake low force groat force one arm 340 are arranged in parallel on one side of the variable valve operating device 200 and are rotatably held by the shaft 341 at the respective central portions. One end of the intake high cam rocker arm 330 extends to bend to the position above the intake high cam 237 (Z direction), and one end of the intake low force mrotker arm 340 is bent to the position above the intake low cam 241 (Z direction) It extends.

[0159] The exhaust cam rocker arm 350 is disposed on the other side of the variable valve apparatus 200, and is rotatably held by a shaft 351 at the center thereof. One end of the exhaust cam rocker arm 350 extends to a position above the exhaust cam 242 (Z direction). As shown in FIG. 12, the intake low cam rocker arm 340 is composed of a cam receiving portion 340T, an arm 340R, an adjuster 342 and a nut 343!

[0161] One end of the arm 340R in the X direction is provided with a cam receiving portion 340T that comes into contact with the intake low cam 241. The other end of the arm 340R is attached with a nut 343 by a nut 343.

[0162] In addition, a pin 345 extending in the Y direction is attached to a portion of the arm 340R near the adjuster 342 so as to protrude below the intake high cam rocker arm 330.

[0163] The intake high cam rocker arm 330 is composed of a cam receiving portion (not shown), an arm 330R, an adjuster 332, and a nut 333 force!

[0164] One end of the arm 330R in the X direction is provided with a cam receiving portion that comes into contact with the intake high cam 237, and an agitator 332 is attached to the other end with a nut 333. The adjuster 332 of the intake high cam rocker arm 330 abuts the upper portion of the pin 345 of the intake low cam rocker arm 340.

[0165] As the intake low cam 241 rotates in the direction of the arrow Q2, the cam receiver 340T moves up and down. As a result, the arm 340R rotates around the shaft 341, and the adjuster 342 moves up and down. Similarly, the cam receiver moves up and down as the intake high cam 237 rotates in the direction of arrow Q2. As a result, the arm 330R rotates about the shaft 341, and the adjuster 332 moves up and down.

[0166] An intake valve 344 is positioned below the adjuster 342 of the intake low cam rocker arm 340. The stem end 344 a at the upper end of the intake valve 344 is in contact with the adjuster 342. The intake valve 344 is provided with a valve spring 347. Valve spring 347 urges intake valve 344 upward!

[0167] As shown in FIG. 5, the length of the cam nose 237A of the intake high cam 237 is larger than the length of the cam nose 241A of the intake low cam 241. Thereby, the downward movement distance of the agitator 332 accompanying the rotation of the intake high cam 237 is larger than the downward movement distance of the agitator 342 accompanying the rotation of the intake low cam 241. When the intake high cam 237 rotates, the downward moving force of the intake high cam rocker arm 330 is transmitted to the intake low cam rocker arm 340 via the pin 345.

Here, in the present embodiment, as shown in FIG. 7, the intake high cam 237 during low rotation is The camshaft 240 can rotate with respect to the cam fixing shaft 244. Therefore, the rotational force of the cam fixing shaft 244 is not transmitted to the intake high cam 237. On the other hand, as shown in FIG. 8, the intake high cam 237 at the time of high rotation is fixed to the cam fixing shaft 244 by lock pins 214 and 217. Therefore, the rotational force of the cam fixing shaft 244 is transmitted to the intake high cam 237.

That is, at the time of low rotation, the intake high cam rocker arm 330 is not driven by the intake high cam 237. Therefore, the adjuster 342 of the intake low cam rocker arm 340 moves up and down by the rotation of the intake low cam 241 and the intake valve 344 moves up and down (lift operation). As a result, the intake valve 344 opens and closes.

On the other hand, at the time of high rotation, intake high cam rocker arm 330 is driven by intake high cam 237. Thereby, the intake low cam rocker arm 340 is driven by the intake high cam rocker arm 330. Therefore, the agitator 342 of the intake low cam rocker arm 340 moves up and down by the rotation of the intake high cam 237, and the intake valve 344 moves up and down (lift operation). As a result, the intake valve 344 opens and closes.

Thus, the rotational force of the intake low cam 241 is transmitted to the intake valve 344 via the intake low cam rocker arm 340, and the rotational force of the intake high cam 237 is transmitted to the intake high cam rocker arm 330 and the intake low cam rocker arm 340. To the intake valve 344. The amount of displacement of the intake valve 344 at low speed (hereinafter referred to as lift amount) depends on the length of the cam nose 241A of the intake low cam 2 41, and the amount of lift of the intake valve 344 at high speed is the cam nose of the intake high cam 237 Depends on the length of 237A.

[0172] Here, in order to bring both the adjuster 332 of the intake high cam rocker arm 330 and the adjuster 342 of the intake low-power murotsu car arm 340 into contact with the stem end 344a of the intake valve 344, the area of the upper surface of the stem end 344a is reduced. It needs to be bigger. On the other hand, in this embodiment, the vertical movement of the intake high cam rocker arm 330 is transmitted to the intake valve 344 via the intake port murotsuker arm 340, so the area of the upper surface of the stem end 344a of the intake valve 3 44 Can be reduced, and an uneven load can be prevented from being applied to the intake valve 344.

[0173] Exhaust cam rocker arm 350 consists of intake high cam rocker arm 330 and intake low Like the cam rocker arm 340, the cam rocker arm 340 includes a cam receiving portion 350T, an arm 350R, an adjuster 352 and a nut 353.

An exhaust valve 354 is positioned below the adjuster 352 of the exhaust cam rocker arm 350. The exhaust valve 354 is provided with a valve spring 357. Valve spring 357 biases intake valve 344 upward. The exhaust cam rocker arm 350 is driven by the exhaust cam 242. Therefore, the adjuster 352 of the exhaust cam rocker arm 350 moves up and down by the rotation of the exhaust cam 242 and the exhaust valve 354 moves up and down (lift operation). As a result, the exhaust valve 354 opens and closes.

[0175] (7) Valve lift amount

FIG. 13 shows lift amounts of intake valve 344 and exhaust valve 354 shown in FIG.

In FIG. 13, the horizontal axis indicates the crank angle (the rotation angle of the crankshaft 23), and the vertical axis indicates the lift amount of the exhaust valve 354 and the intake valve 344 (the vertical direction of the exhaust valve 354 and the intake valve 344). Displacement).

In FIG. 13, the exhaust valve 354 and the intake valve 344 are open when the lift amount is larger than zero, and are closed when the lift amount is zero.

[0178] The crank angle is shown from one 360 ° to + 360 °. Crank angle is 0 °, 36

Piston 21 (Fig. 2) is located at top dead center TDC in cylinder 20 at 0 ° and -360 °, and piston 21 (Fig. 2) is in cylinder 20 when crank angle is 180 ° and-180 °. Located at BDC BDC.

[0179] A valve lift curve 242L indicated by a solid line shows a change in the lift amount of the exhaust valve 354 due to the rotation of the exhaust cam 242 (Fig. 9). According to the valve lift curve 242L, the maximum lift amount of the exhaust valve 354 is the maximum value L1.

[0180] A valve lift curve 241L indicated by a one-dot chain line indicates a change in the lift amount of the intake valve 344 at the time of low rotation. According to the valve lift curve 241L, the maximum lift amount of the intake valve 344 is the maximum value L2. In this case, as described above, the lift amount of the intake valve 344 depends on the length of the cam nose 241 A of the intake low force 241.

[0181] On the other hand, the valve lift curve 237L indicated by the dotted line shows the lift of the intake valve 344 at high speed. Indicates the change in quantity. According to the valve lift curve 237L, the maximum lift amount of the intake valve 344 is a maximum value L1 equal to the maximum lift amount of the exhaust valve 354 larger than the maximum value L2. In this case, as described above, the lift amount of the intake valve 344 depends on the length of the cam nose 237A of the intake high cam 237.

[0182] Thus, the lift amount of the intake valve 344 at the time of high rotation is larger than the lift amount of the intake valve 344 at the time of low rotation. As a result, at the time of high rotation, it is possible to secure a larger amount of intake air to the cylinder 20 in FIG. 2 than at the time of low rotation. As a result, fuel efficiency during normal driving can be improved, harmful substances in exhaust gas can be reduced, and high output during high-speed driving can be realized.

In the present embodiment, the maximum lift amount of the exhaust valve 354 and the maximum lift amount of the intake valve 344 at a high rotation speed are set to be equal! The maximum lift amount of the intake valve 344 may be different from the maximum lift amount of the intake valve 344 at high rotation.

[0184] (8) Effects of the present embodiment

In the present embodiment, a variable valve apparatus 200 that switches between intake high cam 237 and intake low cam 241 using a centrifugal force caused by rotation is used. In this case, compared to the case where the two intake cams are switched by hydraulic pressure, the hydraulic actuator and the hydraulic pump are not required, so that the intake high cam 237 and the intake low cam 241 can be switched at a smaller size and at a lower cost. . As a result, fuel efficiency during normal driving can be improved, harmful substances in exhaust gas can be reduced, and high output during high-speed driving can be realized.

Furthermore, in the present embodiment, the insertion of the lock pins 213 and 217 into the lock pin fitting holes 236b and 236c without using the friction force between the switching force components of the intake high cam 237 and the intake low cam 241 and This is done by drawing. As a result, there is almost no deterioration due to wear of components. As a result, it is possible to extend the life of the variable valve operating apparatus 200 without using wear-resistant components, and to achieve low cost.

[0186] In addition, since the insertion and removal of the lock pins 214 and 217 into and from the lock pin fitting holes 236b and 236c without requiring high machining accuracy is realized with only a mechanical structure, manufacturing is easy. It becomes. [0187] (9) Correspondence between each component of claim and each part of embodiment

Hereinafter, examples of correspondence between each constituent element of the claims and each element of the embodiment will be described, but the present invention is not limited to the following examples.

In the above embodiment, the intake valve 344 and the exhaust valve 354 are examples of valves, the cam fixing shaft 244 is an example of a rotating shaft, and the intake low cam 241 is the first cam member. In this example, the floating cam portion 235 is an example of the second cam member, the lock pin 214, 217 is a force locking member, the springs SI, S2 are examples of the biasing member, and the weights 213, 216 Is an example of a drive member.

[0189] Further, the tips of the lock pins 214 and 217 are examples of locking portions, the lock pin fitting holes 236b and 236c are examples of locked portions, and the lock plate 233 is an example of a movement blocking member. Yes, groove portions 214a, 21 4b, 217a, 217b are examples of groove portions, lock pin locking portions 233b, 233c are examples of fitting portions, and intake low cam rocker arm 340 is an example of a first transmission member The intake high cam knocker arm 330 is an example of the second transmission member.

[0190] Further, the state of the lock pins 214 and 217 at the time of low rotation shown in FIG. 7 is an example of the first state, and the positions of the weights 213 and 216 at the time of low rotation are examples of the first position. The state of the lock pins 214 and 217 at the time of high rotation shown in FIG. 8 is an example of the second state, and the positions of the weights 213 and 2 16 at the time of high rotation are examples of the second position. The lift amount of the intake valve 344 at low speed indicated by the alternate long and short dash line is an example of the first lift amount, and the lift amount of the intake valve 344 at high speed indicated by the dotted line is the second lift amount. It is an example.

[0191] In addition, the engine 7 and the variable valve gear 200 are examples of an engine device, the motorcycle 100 is an example of a vehicle, the rear wheel 11 is an example of a driving wheel, the rear wheel driven sprocket 12, and the drive. Shaft 26, rear wheel drive sprocket 15 and chain 16 are examples of transmission mechanisms.

[0192] As each component of a claim, stated in the claim! Various other elements having similar configurations or functions can also be used.

[0193] (10) Other embodiments

(10- 1)

The variable valve operating apparatus 200 of the above embodiment has two weights 213, 216 and two Only one of the weights 213 and 216 and the lock pins 214 and 217 may be provided. An example of the variable valve gear 200 in that case is shown in FIG.

[0194] The variable valve operating apparatus 200 shown in Fig. 14 does not have the weight 213 and the lock pin 214 in the variable valve operating apparatus 200 shown in Figs.

[0195] Fig. 14 (a) is a cross-sectional view of the variable valve apparatus 200 at low rotation, and Fig. 14 (b) is a diagram of Fig. 14 (a).

A cross-sectional view along line P—P is shown.

As shown in FIG. 14 (a), the variable valve operating apparatus 200 includes a lock pin holding mechanism 210, a cam driven sprocket 220, a lock pin locking mechanism 230, an idle cam portion 235, and a camshaft 2

With 40.

[0197] The lock pin holding mechanism 210 is provided with a weight 216 and a lock pin 217.

As shown in FIGS. 7 and 8, the weight 216 and the lock pin 217 are arranged so that the floating cam portion 235 can be rotated with respect to the cam fixing shaft 244 and fixed according to the rotational speed of the engine 7. Switch.

[0198] Further, the movement of the lock pin 217 is restricted by the lock pin engaging portion 233b of the lock plate 233.

[0199] The lock plate 233 in this case has a long lock pin engaging portion 233b extending along one side of a substantially rectangular support plate 233a, as shown in FIG. 14 (b).

[0200] As in this example, when a set of weight 216 and lock pin 217 is provided in variable valve operating apparatus 200, fuel consumption during normal driving is improved and harmful substances in exhaust gas are reduced. As well as high output during high-speed driving. Further, further miniaturization of the variable valve operating apparatus 200 can be realized.

[0201] (10-2)

In the variable valve operating apparatus 200 of the above embodiment, the operating angle of the intake valve 344 may be changed by switching the intake high cam 237 and the intake low cam 241 to change the lift amount of the intake valve 344. Here, the operating angle of the intake valve 344 refers to a crank angle range in which the intake valve 344 is lifted. For example, in FIG. 13, the working angle of the intake valve 344 is 260 ° (-30 ° force to 230 °). [0202] In this case, the cam nose 237A of the intake high cam 237 is formed wider than the cam nose 241 A of the intake low cam 241. Thus, the operating angle force of the intake valve 344 at high speeds Intake valve at low speeds It becomes larger than the working angle of 344.

[0203] When the length of the cam nose 237A of the intake high cam 237 and the length of the cam nose 241A of the intake low cam 241 are equal to each other, the operating angle of the intake valve 344 can be switched, and the intake high cam 237 is similar to the above embodiment. When the length of the cam nose 237A is larger than the length of the cam nose 241A of the intake low cam 2 41, both the lift amount of the intake valve 344 and the operating angle of the intake valve 344 can be switched.

[0204] (10-3)

The variable valve device 200 according to the present invention may be applied to the exhaust valve 354.

In this case, the floating cam portion, the lock pin locking mechanism, and the cam having the same structure as the floating cam portion 235, the lock pin locking mechanism 230, and the cam driven sprocket 220 so as to be adjacent to the exhaust valve 354. A driven sprocket is provided, and an exhaust and iclot rocker arm having the same structure as the intake high cam rocker arm 330 is provided.

Accordingly, the lift amount of the exhaust valve 354 can be switched.

[0207] (10-4)

In the above-described embodiment, only one of the forces provided on the lock pins 214 and 217 with the two grooves 214a and 217a and the grooves 214b and 217b may be provided, respectively.

[0208] For example, the lock pin 214 may be provided with only the groove 214a, and the lock pin 217 may be provided with only the groove 217a. In this case, at the time of low rotation, the lock pins 233b and 233c force S of the lock plate 233 are fitted into the grooves 214a and 217a of the lock pins 214 and 217, and the movement of the lock pins 214 and 217 is restricted.

[0209] Further, only the groove 214b may be provided on the lock pin 214, and only the groove 217b may be provided on the lock pin 217. In this case, during high rotation, the locking pins 233b and 233c of the lock plate 233 are engaged with the grooves 咅 b and 217b of the lock pins 214 and 217, and the movement of the lock pins 214 and 217 is restricted.

[0210] (10-5) In the above embodiment, the movement blocking member for limiting the movement of the lock pins 214 and 217 is used as a movement blocking member of another shape such as a force pin using the plate-shaped lock plate 233. Also good. In this case, the shape of the grooves 214a, 214b, 217a, 217b formed in the lock pins 214, 217 is appropriately determined according to the shape of the movement preventing member.

[0211] (10-6)

In the above embodiment, the variable valve operating device 200 is provided in the SOHC (single overhead camshaft) engine 7! /, But the variable valve operating device 200 is provided in the engine 7 having a camshaft. It will not be limited if it is the structure provided.

[0212] For example, the engine 7 may be an SV (side valve) engine, an OHV (overhead valve) engine, or a DOHC (double overhead camshaft) engine.

[0213] (10-7)

Further, as described with reference to FIGS. 10 to 12, the variable valve operating apparatus 200 is provided in the engine 7 including the intake high-power murotsuka arm 330, the intake low cam rocker arm 340, and the exhaust cam rocker arm 350. However, the variable valve apparatus 200 may be provided in a direct hitting engine.

[0214] (10-8)

In the above embodiment, the variable valve apparatus 200 uses the springs SI and S2 to bias the weights 213 and 216 in a predetermined direction. However, if it is an elastic body that urges the weights 213 and 216 in a predetermined direction, rubber or the like may be used instead of the springs SI and S2.

[0215] (10-9)

In the above-described embodiment, a motorcycle has been described as a vehicle. However, the present invention is not limited to this, and the variable valve apparatus 200 can also be provided in a small vehicle with a small displacement such as a tractor and a cart and an engine of a small vessel. Industrial applicability

[0216] The present invention can be used for various vehicles, ships and the like equipped with engines such as motorcycles and four-wheeled vehicles.

Claims

The scope of the claims

[1] A variable valve gear for driving an engine valve,

A rotating shaft provided rotatably in conjunction with the rotation of the engine;

A first cam member provided to rotate together with the rotating shaft and acting to open and close the valve;

A second cam member provided rotatably with respect to the rotating shaft and acting to open and close the valve;

A lock provided so as to be able to shift between a first state in which the second cam member is rotatable with respect to the rotating shaft and a second state in which the second cam member is locked with the rotating shaft. Components,

A biasing member that generates a biasing force that causes the locking member to transition to the first state; and a centrifugal force that accompanies the rotation of the rotary shaft causes the locking member to resist the biasing force of the biasing member. A drive member that operates to shift to the second state,

When the locking member is in the first state, the first cam member acts to open and close the valve, and when the locking member is in the second state, the second cam A variable valve operating apparatus in which a member acts to open and close the valve.

[2] The drive member is provided so as to be rotatable from a first position to a second position by a centrifugal force accompanying rotation of the rotating shaft,

The locking member is provided to be movable in one direction along the rotation axis as the driving member rotates from the first position to the second position.

The biasing member applies a biasing force to the drive member such that the drive member is directed toward the first position;

The locking member is in the first state when the driving member is in the first position, and is in the second state when the driving member is in the second position. The variable valve operating device according to 1.

[3] The locking member has a locking portion,

The second cam member has a locked portion locked by the locking portion of the locking member, The locking portion is disengaged from the locked portion when the locking member is in the first state, and the locking portion is locked when the locking member is in the second state. The variable valve operating apparatus according to claim 1, wherein the portion is locked.

[4] The locking member includes a rod-shaped member, the locking portion is an end portion of the rod-shaped member, and the locked portion of the second cam member is fitted with an end portion of the rod-shaped member. The variable valve operating device according to claim 3, wherein the variable valve device is a possible hole.

[5] The locking member is a plurality of rod-shaped members, and the locked portion of the second cam member is a plurality of holes into which ends of the plurality of rod-shaped members can be respectively fitted. 5. The variable valve operating apparatus according to claim 4, wherein the plurality of rod-shaped members are disposed at positions that are asymmetric with respect to a center of the rotating shaft.

6. The variable motion according to claim 1, further comprising a movement preventing member that prevents movement of the locking member when the locking member is in at least one of the first state and the second state. Valve device.

[7] The locking member has at least one groove,

The variable valve according to claim 6, wherein the movement preventing member has a fitting portion that can be fitted into the groove portion when the locking member is in at least one of the first state and the second state. apparatus.

[8] At least one of the case where the locking member shifts from the first state to the second state and the case where the locking member shifts from the second state to the first state. 8. The variable valve operating apparatus according to claim 7, wherein the groove portion and the fitting portion are formed so that the fitting portion of the movement preventing member can be retracted.

[9] a first transmission member that moves the valve up and down by swinging in conjunction with rotation of the first cam member;

2. The variable valve operating apparatus according to claim 1, further comprising a second transmission member that swings the first transmission member in conjunction with rotation of the second cam member.

[10] The first cam member operates to open the valve by a first lift amount in the first state, The variable valve operating apparatus according to claim 1, wherein the second cam member acts to open the valve with a second lift amount larger than the first lift amount in the second state.

[11] The first cam member operates to open the valve at a first operating angle in the first state,

The variable valve operating apparatus according to claim 1, wherein the second cam member acts to open the valve at a second operating angle larger than the first operating angle in the second state.

12. The variable valve operating apparatus according to claim 1, wherein the valve is an intake valve.

[13] an engine having a valve;

A variable valve operating device for driving the valve of the engine, the variable valve operating device,

When the locking member is in the first state, the first cam member acts to open and close the valve, and when the locking member is in the second state, the second cam An engine device in which a member acts to open and close the valve.

[14] an engine device;

Driving wheels,

A transmission mechanism for transmitting the power generated by the engine device to the drive wheel, The engine device is

An engine having a valve;

A variable valve gear for driving the valve of the engine,

The variable valve operating device is:

When the locking member is in the first state, the first cam member acts to open and close the valve, and when the locking member is in the second state, the second cam A vehicle in which a member acts to open and close the valve.