WO2006064707A1

WO2006064707A1 - Valve timing controller, engine device having the same, and vehicle

Info

Publication number: WO2006064707A1
Application number: PCT/JP2005/022484
Authority: WO
Inventors: Minoru Yamamoto; Toshimasa Morita
Original assignee: Yamaha Hatsudoki Kabushiki Kaisha
Priority date: 2004-12-17
Filing date: 2005-12-07
Publication date: 2006-06-22
Also published as: CN100455774C; JP2006170117A; BRPI0519514A2; CN101080552A; US20090272348A1; EP1835133A4; EP1835133A1; TW200624657A

Abstract

A valve timing controller, an engine device having the valve timing controller, and a vehicle. In the valve timing controller, when the speed of an engine is low, a force by a spring energizing a low speed lock pin in a direction for inserting the low speed lock pin into a low speed pin lead-in hole becomes larger than a centrifugal force acting on a weight. Accordingly, the low speed lock pin is inserted into the low speed pin lead-in hole, and the phase of an intake camshaft relative to an exhaust camshaft is fixed. When the speed of the engine is high, a force by the centrifugal force acting on the weight energizing the high speed lock pin in a direction for inserting the high speed lock pin into a high speed pin lead-in hole becomes larger than a force by the spring energizing the high speed lock pin in a direction for extracting the high speed lock pin from the high speed pin lead-in hole. Thus, the high speed lock pin can be inserted into the high speed pin lead-in hole, and the phase of the intake camshaft relative to the exhaust camshaft can be fixed.

Description

Specification

TECHNICAL FIELD Field of the Invention

The present invention relates to a valve timing control device that variably controls a valve timing of an engine, and an engine device and a vehicle including the same.

Background art

Conventionally, various variable valve timing mechanisms that control the opening / closing timing of intake valves or exhaust valves for the purpose of improving fuel efficiency, reducing harmful substances in exhaust gas, and increasing output in the target rotation range ( WT: Variable Valve Timing) has been developed.

[0003] There are variable variable timing mechanisms using, for example, an actuator such as a hydraulic cylinder or an electric motor. However, these actuators are expensive. In addition, if such an actuator is used, the variable valve timing mechanism becomes large.

[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, motorcycles require a cheaper and smaller variable valve timing mechanism. Therefore, it has been difficult to use the variable valve timing mechanism using the above-described actuator for a motorcycle.

[0005] Therefore, a rotation phase generator has been proposed as a variable valve timing mechanism that can be miniaturized (see Patent Document 1).

[0006] In this rotational phase generator, an input member having two intermediate members is rotated as the engine rotates. When the centrifugal force acting on the weights of the two intermediate members becomes greater than the biasing force of the coil spring that connects the two intermediate members, the rotational phase of the input member and the output member connected to the camshaft changes, causing valve timing. Changes.

[0007] Since such a rotational phase generator is controlled in valve timing by a mechanical structure, low cost can be realized and the size can be reduced.

However, the following problems have been pointed out with this rotational phase generator.

[0009] In the rotational phase generation device of Patent Document 1,! The centrifugal force acting on the weight part and the biasing force of the coil spring are balanced in a certain rotational speed range. If the engine speed continues in this speed range, the change in valve timing becomes unstable, and a phenomenon called hunting occurs in which the valve behavior becomes unstable.

[0010] Such hunting causes noise and decreases the durability of the component parts.

In particular, engine performance and durability may be reduced if the cam profile changes due to hunting.

[0011] On the other hand, there is a valve timing control device with reduced hunting (see Patent Document 2). In order to reduce hunting, this valve timing control device employs a mechanism (one-way clutch mechanism) that fixes the positional relationship between the camshaft and the driven sprocket before and after the change of rotational torque fluctuation.

Patent Document 1: Japanese Patent Laid-Open No. 9-324614

Patent Document 2: Japanese Utility Model Publication No. 5-21104

Disclosure of the invention

Problems to be solved by the invention

[0012] In order to realize a one-way clutch mechanism, however, high processing accuracy is required for the constituent members of the mechanism. Therefore, the one-way clutch mechanism is not easy to manufacture.

[0013] Furthermore, this one-way clutch mechanism is realized by a frictional force that acts between the inner peripheral surface of the driven sprocket body and the above-mentioned constituent members. In this case, since the constituent members are easily deteriorated by friction, it is necessary to use a material having high wear resistance. As a result, cost reduction becomes difficult.

Means for solving the problem

[0014] An object of the present invention is to provide a valve timing control device that can be easily manufactured and that can be reduced in size and cost, and an engine device and a vehicle including the valve timing control device.

[0015] (1)

A valve timing control device according to an aspect of the present invention is configured to perform a first operation according to the engine speed. A valve timing control device that controls the opening and closing timing of the first and second valves, and is provided so as to be in contact with the first valve and a rotating member that is rotatable in conjunction with the rotation of the engine. The first camshaft that opens and closes the first valve by rotating together with the member is abutted against the first camshaft and the second valve and is relatively rotatable with respect to the first camshaft, and rotates with the rotating member. A second camshaft that opens and closes the second valve, and a phase change mechanism that changes the phase of the second camshaft relative to the first camshaft to the first phase and the second phase. Prepare.

[0016] The phase changing mechanism includes a first locking mechanism that locks the second cam shaft in a state where the second cam shaft has the first phase with respect to the first cam shaft, A second locking mechanism that locks the second camshaft with the second camshaft having a second phase with respect to the camshaft. The first locking mechanism is urged in a direction to lock the second camshaft, and is provided so as to be movable in a direction to release the locking of the second camshaft by centrifugal force. The locking mechanism is urged in a direction to release the locking of the second camshaft, and is provided so as to be movable in a direction to lock the second camshaft by centrifugal force.

In the valve timing control device, the rotating member rotates in conjunction with the rotation of the engine, and the first cam shaft and the second cam shaft rotate with the rotation of the rotating member. As a result, the first valve that contacts the first camshaft and the second valve that contacts the second camshaft open and close. Here, the second camshaft is rotatable relative to the first camshaft.

[0018] In the phase change mechanism, the first locking mechanism is urged in the direction to lock the second camshaft, and the second locking mechanism releases the locking of the second camshaft. Is being energized.

[0019] As the rotating member rotates, a centrifugal force acts on each of the first locking mechanism and the second locking mechanism. The centrifugal force acts so that the first locking mechanism unlocks the second camshaft, and the second locking mechanism locks the second camshaft.

[0020] When the engine speed is low, in the first locking mechanism, the urging force in the direction of locking the second camshaft acts to release the locking of the second camshaft. Centrifugal force Bigger than. Thereby, the second camshaft is locked by the first locking mechanism. At this time, in the second locking mechanism, the urging force in the direction of releasing the locking of the second camshaft becomes larger than the centrifugal force acting in the direction of locking the second camshaft. Thereby, the second camshaft is not locked by the second locking mechanism. As a result, the second cam shaft is locked in a state having the first phase with respect to the first camshaft by the first locking mechanism.

[0021] When the engine speed is high, the biasing force in the direction of locking the second camshaft acts to release the locking of the second camshaft in the first locking mechanism. Less than centrifugal force. As a result, the second camshaft is not locked to the first locking mechanism. At this time, in the second locking mechanism, the urging force in the direction of releasing the locking of the second camshaft is smaller than the centrifugal force acting in the direction of locking the second camshaft. Thereby, the second camshaft is locked by the second locking mechanism. As a result, the second camshaft is locked in a state having the second phase with respect to the first camshaft by the second locking mechanism.

[0022] In this way, the phase of the second camshaft with respect to the first camshaft is changed by changing the engine speed from a low engine speed to a high engine speed or a high engine speed to a low engine speed. It is changed between the first phase and the second phase. Thereby, the opening and closing timings of the first and second valves are controlled according to the engine speed.

[0023] Further, based on the mutually complementary movement of the first and second locking mechanisms without using the frictional force between the structural members, the switching force of the phase of the second camshaft with respect to the first camshaft. Done. Thereby, there is almost no deterioration due to wear of the component parts. As a result, the life of the valve timing control device can be extended without using wear-resistant components, and low cost can be realized.

[0024] Furthermore, since the complementary movement of the first and second locking mechanisms can be realized with only a mechanical structure without requiring high machining accuracy, the manufacturing is facilitated. Further, since a control system constituted by a hydraulic circuit, an electric circuit, software, and the like for controlling the moving operation of the first and second locking mechanisms is not required, the valve timing control device can be reduced in size. [0025] (2)

The first locking mechanism is movable to a first locking portion provided on the second camshaft, a state locked to the first locking portion, and a state released from the first locking portion. A first engaged member provided on the first engaging member, a first urging member that urges the first engaged member in a direction to be engaged with the first engaging member, and a first urging member by centrifugal force. A first weight that moves the locked member in a direction away from the first locking member force, and the second locking mechanism includes a second locking portion provided on the second camshaft. A second locked member movably provided in a state locked to the second locking portion and a state where the second locking portion force is disengaged; and A second urging member for urging in a direction away from the locking portion, and a second weight for moving the second locked member in a direction locked by the second locking portion by centrifugal force And the second camshaft is The first phase with respect to the first camshaft with the first locked member disengaged from the first locking portion force and the second locked member disengaged from the second locking portion. It may be provided so as to be rotatable relative to the second phase! /.

[0026] When the engine speed is low, in the first locking mechanism, the force of the first urging member becomes larger than the centrifugal force acting on the first weight. Accordingly, the first locked member is locked to the first locking portion, and the second camshaft is locked by the first locking mechanism. At this time, in the second locking mechanism, the force of the second urging member is larger than the centrifugal force acting on the second weight. Accordingly, the second locked member is disengaged from the second locking portion force, and the second cam shaft is not locked by the second locking mechanism. As a result, the second camshaft is locked in a state having the first phase with respect to the first camshaft by the first locking mechanism.

When the engine speed is high, in the first locking mechanism, the force of the first urging member is smaller than the centrifugal force acting on the first weight. Accordingly, the first locked member is disengaged from the first locking portion, and the second camshaft is not locked by the first locking mechanism. At this time, in the second locking mechanism, the force of the second urging member is smaller than the centrifugal force acting on the second weight. Thus, the second locked member is inserted into the second locking portion, and the second force shaft is locked by the second locking mechanism. As a result, the second camshaft is locked in a state having the second phase with respect to the first camshaft by the second locking mechanism.

[0028] When the engine speed changes to a low engine speed, the first lock In the mechanism, the force of the first urging member is smaller than the centrifugal force acting on the first weight. As a result, the second camshaft that has been locked by the first locking mechanism is not locked by the first locking mechanism. As a result, the second camshaft rotates from the first phase to the second phase with respect to the first camshaft.

[0029] When the rotational speed of the engine is high and the rotational speed is also changed to a low rotational speed, the force of the second urging member in the second locking mechanism is greater than the centrifugal force acting on the second weight. growing. As a result, the second camshaft that has been locked by the second locking mechanism is not locked by the second locking mechanism. As a result, the second camshaft rotates from the second phase to the first phase with respect to the first camshaft.

[0030] In this way, the first and second locking portions, the first and second locked members, the first and second urging members, and the first and second weights are simplified. With the configuration, the first and second locking mechanisms can be moved in a complementary manner.

[0031] (3)

The first locking portion is a first hole provided in the second camshaft, and the first locked member is inserted into the first hole and the first hole The first pin member is provided so as to be movable in a state of being pulled out from the second locking portion, and the second locking portion is a second hole portion provided in the second camshaft, The locked member may be a second pin member that is movably provided in a state of being inserted into the second hole and in a state of being released from the second hole force.

[0032] When the engine speed is low, the force of the first urging member in the first locking mechanism is greater than the centrifugal force acting on the first weight. As a result, the first pin member is inserted into the first hole, and the second camshaft is locked by the first locking mechanism. At this time, in the second locking mechanism, the force of the second urging member becomes larger than the centrifugal force acting on the second weight. As a result, the second pin member is pulled out from the second hole, and the second camshaft is not locked by the second locking mechanism. As a result, the second camshaft is locked by the first locking mechanism in a state having the first phase with respect to the first camshaft.

[0033] When the engine speed is high, in the first locking mechanism, the force of the first biasing member is smaller than the centrifugal force acting on the first weight. As a result, the first pin member is The second camshaft comes off the hole and is not locked by the first locking mechanism. At this time, in the second locking mechanism, the force of the second urging member is smaller than the centrifugal force acting on the second weight. As a result, the second pin member is inserted into the second hole, and the second camshaft is locked by the second locking mechanism. As a result, the second camshaft is locked in a state having the second phase with respect to the first camshaft by the second locking mechanism.

[0034] When the rotational speed of the engine changes to a high rotational speed, the force of the first urging member in the first locking mechanism is greater than the centrifugal force acting on the first weight. Get smaller. As a result, the second camshaft that has been locked by the first locking mechanism is not locked by the first locking mechanism. As a result, the second camshaft rotates from the first phase to the second phase with respect to the first camshaft.

[0035] When the engine speed is high and the engine speed is also changed to a low engine speed, in the second locking mechanism, the force of the second urging member is greater than the centrifugal force acting on the second weight. growing. As a result, the second camshaft that has been locked by the second locking mechanism is not locked by the second locking mechanism. As a result, the second camshaft rotates from the second phase to the first phase with respect to the first camshaft.

[0036] In this way, with the first and second holes, the first and second pin members, the first and second urging members, and the first and second weights, with a simple configuration, Complementary movements of the first and second locking mechanisms are realized.

[0037] (4)

The phase changing mechanism may further include a restricting mechanism that restricts the rotational operation of the second camshaft relative to the first camshaft to a range between the first phase and the second phase.

[0038] When the rotational speed of the engine changes to a low rotational speed, the second camshaft locked by the first locking mechanism is locked by the first locking mechanism. No longer. As a result, the second camshaft rotates from the first phase to the second phase with respect to the first camshaft.

[0039] Here, the rotation operation of the second camshaft with respect to the first camshaft is restricted to a range between the first phase and the second phase by the restriction mechanism. The camshaft rotation is reliably stopped in the second phase. In this state, it is locked by the first locking mechanism. The second camshaft that has been removed is locked by the second locking mechanism.

[0040] When the rotational speed of the engine changes to a low rotational speed, the second camshaft locked by the second locking mechanism is locked by the second locking mechanism. Disappear. As a result, the second camshaft also rotates the second phase force to the first phase with respect to the first camshaft.

[0041] Here, the rotation operation of the second camshaft with respect to the first camshaft is restricted to a range between the first phase and the second phase by the restriction mechanism. The camshaft rotation is reliably stopped in the first phase. In this state, the second camshaft that has been locked by the second locking mechanism is locked by the first locking mechanism.

[0042] (5)

The restriction mechanism prevents the rotation of the second camshaft when the phase of the second camshaft with respect to the first camshaft changes from the first phase to the second phase, and A blocking mechanism may be included that prevents the rotation of the second camshaft when the phase of the second camshaft changes from the second phase to the first phase.

[0043] When the engine speed of the engine is low and the engine speed is also changed to a high engine speed, the second cam shaft rotates the first phase force to the second phase with respect to the first cam shaft. Here, the rotation of the second camshaft with respect to the first camshaft is surely stopped in the second phase by the blocking mechanism.

[0044] When the engine speed changes from a high speed to a low speed, the second camshaft rotates with respect to the first camshaft so that the second phase force also rotates to the first phase. To do. Here, the rotation of the second camshaft with respect to the first camshaft is surely stopped in the first phase by the blocking mechanism.

[0045] Thereby, the phase of the second camshaft with respect to the first camshaft can be easily and reliably changed between the first and second phases.

[0046] (6)

The blocking mechanism includes a groove provided on the second camshaft along the circumferential direction, and a contact member that is fixed to the rotating member, is movable within the groove, and is capable of contacting both end surfaces of the groove. And may be included. [0047] When the engine speed at a low engine speed changes to a high engine speed, the second camshaft rotates with respect to the first camshaft to the second phase as well. Here, the rotation of the second camshaft relative to the first camshaft is reliably stopped in the second phase by the abutting member coming into contact with one end in the groove.

[0048] When the rotational speed of the engine is high and the rotational speed is also changed to a low rotational speed, the second camshaft rotates with respect to the first camshaft so that the second phase force also shifts to the first phase. Here, the rotation of the second camshaft with respect to the first camshaft is reliably stopped in the first phase by the abutting member abutting against the other end in the groove.

[0049] Thus, the phase of the second camshaft with respect to the first camshaft can be easily and reliably changed between the first and second phases.

[0050] (7)

In an engine device according to another aspect of the present invention, an engine having first and second valves, and a valve timing control device that controls opening and closing timings of the first and second valves in accordance with the engine speed. The valve timing control device includes a rotating member that is rotatably provided in conjunction with the rotation of the engine, and a first valve that is provided so as to contact the first valve and rotates together with the rotating member. The first camshaft that opens and closes the first camshaft and the second camber, is provided so as to be rotatable relative to the first camshaft, and opens and closes the second valve by rotating together with the rotating member. A phase change mechanism that changes the phase of the second camshaft relative to the first camshaft to a first phase and a second phase. The mechanism includes a first locking mechanism that locks the second camshaft with the second camshaft having the first phase with respect to the first camshaft, and the first camshaft. And a second locking mechanism that locks the second camshaft in a state where the second camshaft has the second phase. The first locking mechanism engages the second camshaft. The second camshaft is urged in the direction of stopping and movable in the direction of releasing the locking of the second camshaft by centrifugal force, and the second locking mechanism releases the locking of the second force shaft. And is movably provided in the direction in which the second camshaft is locked by centrifugal force.

[0051] In the engine device, the engine speed is controlled by a noble timing control device. The opening / closing timing of the first and second valves is controlled accordingly.

[0053] In the phase changing mechanism, the first locking mechanism is biased in the direction to lock the second camshaft, and the second locking mechanism releases the locking of the second camshaft. Is being energized.

As the rotating member rotates, a centrifugal force acts on each of the first locking mechanism and the second locking mechanism. The centrifugal force acts so that the first locking mechanism unlocks the second camshaft, and the second locking mechanism locks the second camshaft.

[0055] When the engine speed is low, in the first locking mechanism, the biasing force in the direction of locking the second camshaft acts to release the locking of the second camshaft. Greater than centrifugal force. Thereby, the second camshaft is locked by the first locking mechanism. At this time, in the second locking mechanism, the urging force in the direction of releasing the locking of the second camshaft becomes larger than the centrifugal force acting in the direction of locking the second camshaft. Thereby, the second camshaft is not locked by the second locking mechanism. As a result, the second cam shaft is locked in a state having the first phase with respect to the first camshaft by the first locking mechanism.

[0056] When the engine speed is high, the biasing force in the direction of locking the second camshaft acts to release the locking of the second camshaft in the first locking mechanism. Less than centrifugal force. As a result, the second camshaft is not locked to the first locking mechanism. At this time, in the second locking mechanism, the urging force in the direction of releasing the locking of the second camshaft is smaller than the centrifugal force acting in the direction of locking the second camshaft. Thereby, the second camshaft is locked by the second locking mechanism. As a result, the second camshaft is locked in a state having the second phase with respect to the first camshaft by the second locking mechanism. [0057] In this way, the phase of the second camshaft with respect to the first camshaft is changed by changing the rotational speed of the engine from a low rotational speed to a high rotational speed, or from a high rotational speed to a low rotational speed. It is changed between the first phase and the second phase. Thereby, the opening and closing timings of the first and second valves are controlled according to the engine speed.

[0058] Further, the switching force of the phase of the second camshaft relative to the first camshaft is based on the mutually complementary moving operations of the first and second locking mechanisms without using the frictional force between the constituent members. Done. Thereby, there is almost no deterioration due to wear of the component parts. As a result, the life of the valve timing control device can be extended without using wear-resistant components, and low cost can be realized.

[0059] Further, since the complementary movement of the first and second locking mechanisms can be realized by only the mechanical structure without requiring high machining accuracy, the manufacturing is facilitated. Therefore, a high-performance and highly durable engine device is realized. In addition, since a control system composed of a hydraulic circuit, an electric circuit, and software for controlling the moving operation of the first and second locking mechanisms is necessary, the valve timing control device can be downsized. The engine device can also be reduced in size.

[0060] (8)

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 first and second valves. And a valve timing control device that controls the opening and closing timings of the first and second valves in accordance with the rotational speed of the engine. The valve timing control device is rotatably provided in conjunction with the engine rotation. A rotating member, a first camshaft provided to contact the first valve and opening and closing the first valve by rotating together with the rotating member; a first force contacting the second valve; A second camshaft which is provided so as to be rotatable relative to the shaft and which opens and closes the second valve by rotating together with the rotating member; and a first camshaft A phase change mechanism that changes the phase of the second force shaft relative to the shaft to a first phase and a second phase, wherein the phase change mechanism is a second camshaft with respect to the first camshaft. A first locking mechanism for locking the second camshaft in a state where the first camshaft has the first phase, and a second locking mechanism with respect to the first camshaft. A second locking mechanism that locks the second camshaft in a state where the camshaft has the second phase, and the first locking mechanism is configured to lock the second camshaft. In addition to being biased, the second camshaft is provided so as to be movable in the direction of releasing the locking of the second camshaft by centrifugal force, and the second locking mechanism releases the locking of the second camshaft. And is movably provided in a direction to lock the second camshaft by centrifugal force.

[0061] 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 timing control device controls the opening and closing timings of the first and second valves according to the engine speed.

[0062] In this case, in the valve timing control device of the engine device, deterioration due to wear of the components hardly occurs. As a result, the life of the valve timing control device can be extended and the low cost can be achieved without using wear-resistant components.

[0063] Furthermore, since the complementary movement of the first and second locking mechanisms can be realized with only a mechanical structure without requiring high machining accuracy, the manufacture is facilitated. Therefore, a high-performance and highly durable vehicle is realized. In addition, since a control system composed of a hydraulic circuit, an electric circuit, software, and the like for controlling the moving operation of the first and second locking mechanisms is required, the valve timing control device and the engine device can be downsized. This makes it possible to reduce the size of the vehicle.

The invention's effect

[0064] In the valve timing control device according to the present invention, the deterioration due to wear of the components hardly occurs. As a result, the lifetime of the valve timing control device can be extended without using wear-resistant components, and low cost can be realized. Furthermore, since the complementary movement of the first and second locking mechanisms can be realized by only the mechanical structure without requiring high machining accuracy, the manufacturing becomes easy. Therefore, a high-performance and highly durable valve timing control device, engine device, and vehicle are realized. Also, a hydraulic circuit and an electric circuit for controlling the moving operation of the first and second locking mechanisms In addition, since a control system constituted by software and the like is not required, the valve timing control device can be downsized, and the engine device and the vehicle can be downsized.

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 an outline of a valve timing control device according to an embodiment of the present invention.

FIG. 3 is an assembled perspective view for explaining the structure of the valve timing control device.

FIG. 4 is an assembled perspective view for explaining the structure of the valve timing control device.

FIG. 5 is an assembled perspective view for explaining the structure of the valve timing control device.

[Fig. 6] Fig. 6 is a detailed cross-sectional view of the cylinder head along the line P-P in Fig. 2 (b)

[Fig. 7] Fig. 7 is an external side view of the cylinder head with the side cover of Fig. 6 removed.

[FIG. 8] FIG. 8 is a partially cutaway cross-sectional view of the cylinder head RR line of FIG.

[Fig. 9] Fig. 9 is a diagram for explaining the relationship between the phase of the exhaust cam and intake cam with respect to the crankshaft in Fig. 2 and the lift amount of the exhaust valve and intake valve caused by the rotation of the crankshaft.

FIG. 10 is a cutaway perspective view for explaining the operation of the valve timing control device. [FIG. 11] FIG. 11 is a cutaway perspective view for explaining the operation of the valve timing control device. FIG. 13 is a cutaway perspective view for explaining the operation of the valve timing control device. [FIG. 13] FIG. 13 is a cutaway perspective view for explaining the operation of the valve timing control device. [FIG. Cutaway perspective view for explaining operation Best mode for carrying out the invention

Hereinafter, a valve timing control device according to an embodiment of the present invention, and an engine device and a vehicle including the same will be described. In the present embodiment, a small motorcycle having a displacement of about 250 cc or less will be described as a vehicle.

In the motorcycle 100, the head pipe 3 is provided at the front end of the main body frame 6. A front fork 2 is provided on the head pipe 3 so that it can swing left and right. The 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.

[0069] The 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.

[0070] A rear arm 10 is connected to the main body frame 6 so as to extend to the rear of the engine 7.

. The rear arm 10 holds the rear wheel 11 and the rear wheel driven sprocket 12 rotatably.

. An exhaust pipe 13 is connected to the exhaust port of the engine 7. A muffler 14 is attached to the rear end of the exhaust pipe 13.

[0071] The 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.

[0072] The engine 7 includes a noble timing control device. The valve timing control device according to this embodiment will be described below.

FIG. 2 is a diagram for explaining the outline of the valve timing control device according to the embodiment of the present invention. Fig. 2 (a) shows a schematic top view of the nozzle timing control device installed inside the engine 7, and Fig. 2 (b) shows a schematic side view of the nozzle timing control device installed inside the engine 7. It is shown.

[0074] As shown in FIG. 2, the valve timing control device 200 is provided in the cylinder head 7S.

. The valve timing control device 200 includes a cam driven sprocket 220, an intake cam 231, and an air cam 241.

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 cam drive sprocket 24 is transmitted to cam driven sprocket 220 of valve timing control device 200 via chain 25. As a result, the valve timing control device 200 rotates.

In valve timing control device 200, the position correlation between intake cam 231 and exhaust cam 241 changes according to the rotational speed of engine 7 and changes in the rotational speed (increase and decrease in rotational speed). As a result, the valve timing changes. The details of the configuration and operation of the noble timing control apparatus 200 will be described. 3 to 5 are assembled perspective views for explaining the structure of the valve timing control device 200. FIG.

. In Fig. 3 to Fig. 5, as shown by arrows X, Υ and Z, the three directions orthogonal to each other are the X direction.

, Y direction and Z direction.

[0079] The noreve timing control device 200 is roughly divided into a lock pin holding mechanism 210 (see FIG. 3).

The cam driven sprocket 220 (see Fig. 4), intake camshaft 230 (see Fig. 5) and exhaust camshaft 240 (see Fig. 5) are also configured! RU

FIG. 3 shows an assembly perspective view of the lock pin holding mechanism 210. As shown in Figure 3

The two support members 211 and 212 having a longitudinal shape in the Z direction are arranged at a predetermined interval in the X direction.

[0081] The support member 211 has a substantially arc-shaped plate-like portion 211A that is parallel to the XZ plane and has a longitudinal shape in the Z direction. One side of the plate-like portion 211A along the Z direction is formed in an arc shape, and the other side is formed in a straight line shape. Through holes 21 la are formed in the vicinity of the upper end and the lower end of the plate-like portion 211A, respectively.

Projection pieces 211B and 211D are formed so as to extend in the Y direction from the upper end portion and the lower end portion of one side along the Z direction of the plate-like portion 211A. Further, a spring holding piece 211C is formed that extends in the X direction from the center lower portion of one side along the Z direction of the plate-like portion 211A and is bent in the Y direction.

[0083] Through holes 211b, 211d, and 211c are formed in the projecting pieces 211B and 211D and the spring holding piece 211C, respectively. The lengths of the protruding pieces 21 IB and 211D and the spring holding piece 211C in the heel direction are shorter in the order of the protruding piece 211B, the spring holding piece 211C, and the protruding piece 21 ID. Accordingly, the through holes 211b, 211c, and 211d approach the plate-like portion 211A in this order in the Y direction.

The support member 212 has a structure that is substantially symmetric with respect to the support member 211 with respect to the XZ plane. Projection pieces 212B and 212D are formed so that the upper end and lower end forces on one side along the Z direction of the plate-like portion 212A also extend in the Y direction.

[0085] Through holes 212a are formed in the vicinity of the upper end and the lower end of the plate-like portion 212A, respectively. In addition, the plate-like portion 212A extends in the X direction from the upper center of one side along the Z direction. A spring holding piece 212C bent in the Y direction is formed. Through holes 212b, 212d, and 212c are formed in the protruding pieces 212B and 212D and the spring holding piece 212C, respectively.

It should be noted that the lengths of the protrusions 212B and 212D of the support member 212 in the Y direction are equal to the lengths of the protrusions 21 IB and 211D of the support member 211 in the Y direction. Further, the length of the spring holding piece 212C of the support member 212 in the Y direction is different from the length of the spring holding piece 211C of the support member 211 in the Y direction.

[0087] 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. A groove along the Y direction on one side (bottom surface) of the weight body 213a parallel to the XY plane

213b and a protruding portion 213c protruding in the Z direction are formed. The protrusion 213c has a through hole extending in the X direction.

[0088] The extension 213d is formed so as to extend in the Y direction from the other surface (upper surface) parallel to the XY plane of the weight main body 213a. The two cylindrical portions 213e are formed along the X direction at both ends of the extension portion 213d in the X direction.

[0089] 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 like a hook.

[0090] High speed lock pins 214 extending in the Y direction are attached to the two hook portions 213f. A support pin 214t extending in the X direction is formed at one end of the high-speed lock pin 214. By attaching the support pin 214t to the hook portion 213f, the high-speed lock pin 214 is rotatably held by the weight 213. A part of the high-speed lock pin 214 can come into contact with the groove 213b.

[0091] The rotating shaft 215 force S is inserted into the cylindrical rod 213e of the way rod 213. As a result, the weight 213 is rotatably held up to the rotation shaft 215ί. In this state, both ends of the rotation shaft 215 are supported by the support member 21.

I and 212 are inserted into the through holes 211b and 212b. Accordingly, the weight 213 is supported by the support member 2

I I, 212 is held rotatably.

The weight 216 has the same structure as the weight 213. However, when the lock pin holding mechanism 210 is assembled, the weight 216 is fixed to the weight 213 with respect to an axis parallel to the X direction. Arranged so as to be symmetrical.

In FIG. 3, the weight body 216a of the weight 216, the extension part 216d, the two cylindrical parts 216e, and the two hooks 216f are the weight body 213a of the weight 213, the extension part 213d, and the two cylindrical parts 213e. And two hook parts 213f.

Further, the groove 216b and the protrusion 216c of the weight 216 correspond to the groove 213b and the protrusion 213c of the weight 213.

[0095] Low speed lock pins 217 extending in the Y direction are attached to the two hook portions 216f. The low speed lock pin 217 is shorter than the high speed lock pin 214. A support pin 217t extending in the X direction is formed at one end of the low speed lock pin 217. By attaching the support pin 217t to the hook portion 216f, the low speed lock pin 217 is rotatably held by the weight 216. The low-speed lock pin 217 has a limited range of rotation as will be described later. As a result, the low-speed lock pin 217 does not contact the groove 216b.

The rotation 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 rotation shaft 218 are supported by the support member 21.

I and 212 are inserted into the through holes 211d and 212d. As a result, the weight 216 is attached to the support member 2.

I I, 212 is held rotatably.

[0097] With the above configuration, the weights 213 and 216 are arranged to face each other in the Z direction.

A screw 219 is inserted into each of the two through holes 21 la of the support member 211 and the two through holes 212 a of the support member 212.

FIG. 4 is an assembly perspective view of the lock pin holding mechanism 210 and the cam driven sprocket 220. When the lock pin holding mechanism 210 and the cam driven sprocket 220 are assembled, the cam driven sprocket 220 is arranged to be parallel to the XZ plane.

[0100] In FIG. 4, in the lock pin holding mechanism 210, both ends of the spring S1 are attached to the through hole provided in the protrusion 213c of the weight 213 and the through hole 211c of the spring holding piece 211C. Further, in the lock pin holding mechanism 210, both ends of the spring S2 are attached to the through hole provided in the protrusion 216c of the weight 216 and the through hole 212c of the spring holding piece 212C. [0101] As shown in FIG. 4, the cam driven sprocket 220 has a plurality of through holes 220a to 220f. A through hole 220a having a diameter larger than that of the other through holes is formed in the center of the cam driven sprocket 220 !.

[0102] Four through holes 220b, 220c, 220e, and 220f are formed at equal angular intervals on one circle centered on the through hole 220a of the cam driven sprocket 220. Four through holes 220d are formed at equiangular intervals on other circles centering on the through hole 220a of the cam dribbon socket 220. Each of the four through holes 220d is threaded.

[0103] Further, on one surface 220A of the cam driven sprocket 220, a protrusion 220T is formed in the vicinity of the through hole 220c.

[0104] The four through holes 220d of the cam driven sprocket 220 are screwed into the screws 219 of the lock pin holding mechanism 210, respectively. As a result, the lock pin holding mechanism 210 is fixed to the one surface 220A side of the cam driven sprocket 220.

[0105] When the lock pin holding mechanism 210 is fixed to the cam driven sprocket 220, the high speed lock pin 214 is inserted into the through hole 220b, and the low speed lock pin 217 is inserted into the through hole 220c. With the structure described in FIG. 3, the high speed lock pin 214 does not protrude from the other side 220B side of the cam driven sprocket 220, and the low speed lock pin 217 has a predetermined length on the other side 220B side of the cam driven sprocket 220. Protruding.

[0106] On the other surface 220B side of the cam driven sprocket 220, the one end forces of the two fixing pins 230A and 230B extending in the Y direction are respectively inserted through the fixing 220e and 220f and fixed.

FIG. 5 is an assembled perspective view of the structure assembled as shown in FIG. 4 (hereinafter referred to as an assembled structure), the intake camshaft 230, and the exhaust camshaft 240. As shown in FIG. The intake camshaft 230 and the exhaust camshaft 240 are both arranged such that their axis J is parallel to the Y direction.

As shown in FIG. 5, the intake camshaft 230 is formed of an intake cam 231, a stepped portion 232, and a rotation shaft 233.

[0109] The intake camshaft 230 in the Y direction has a cylindrical rotating shaft 233 on one end side in the Y direction, and a step having a diameter slightly larger than the diameter of the rotating shaft 233 in the center. And a suction cam 231 on the other end side.

[0110] A rotating through hole 230H extending in the Y direction from the center of the end surface of the rotating shaft 233 to the center of the end surface of the intake cam 231 is formed. That is, the rotation through hole 230H is formed so that the one end force of the intake camshaft 230 in the Y direction also extends to the other end.

[0111] A high-speed pin introduction hole 233c, a low-speed pin introduction hole 233d, and two pin floating grooves 233a and 233b are formed on the end surface of the rotating shaft 233 on a circle centered on the axis J. .

[0112] The high-speed pin introduction hole 233c and the low-speed pin introduction hole 233d are formed so as to be substantially opposed to each other via the rotation through hole 230H. However, the high-speed pin introduction hole 233c and the low-speed pin introduction hole 233d are arranged so that the straight line connecting them does not pass through the axis J! RU

[0113] The pin floating grooves 233a and 233b are formed so as to extend along the circumferential direction around the axis J and to face each other via the rotation through hole 230H.

[0114] The exhaust camshaft 240 has an exhaust cam 241, a step 242, a cam fixing shaft 243, and a protruding shaft

244.

[0115] The exhaust camshaft 240 has a cam fixing shaft 243 extending in the Y direction on one end side in the Y direction, a step 242 and an exhaust cam 241 in the center, and the Y direction on the other end. It has a protruding shaft 244 that extends. A sprocket screw hole 240H is formed at the end of the cam fixing shaft 243.

[0116] When the assembled structure, the intake camshaft 230, and the exhaust camshaft 240 are assembled, the intake camshaft 230 and the exhaust camshaft 240 are attached to the other surface 220B side of the cam driven sprocket 220.

That is, the cam fixing shaft 243 of the exhaust camshaft 240 is inserted into the rotation through hole 230H of the intake camshaft 230. As a result, the exhaust camshaft 240 holds the intake camshaft 230 rotatably. Furthermore, one end of the cam fixing shaft 243 of the exhaust camshaft 240 is inserted into the through hole 220a from the other surface 220B side of the cam driven sprocket 220.

[0118] In this state, the sprocket screw 250 is screwed into the sprocket screw hole 240H of the cam fixed shaft 243 from the one surface 220A side of the cam driven sprocket 220. As a result, the exhaust camshaft 240 is fixed to the cam driven sprocket 220.

[0119] It should be noted that the exhaust cam 241 of the exhaust cam shaft 240, the step 242, the cam fixing shaft 243 and The protruding shafts 244 may be formed integrally with each other! / ヽ may be formed individually. In addition, the intake cam 231, the stepped portion 232, and the rotating shaft 233 of the intake camshaft 230 may be integrally formed! / May be formed individually!

[0120] Further, although not shown in FIG. 5, a connecting mechanism between the cam fixing shaft 243 and the through hole 220a is provided with a fixing mechanism that restricts the rotation of the exhaust camshaft 240 with respect to the force driven sprocket 220. Also good.

[0121] In this fixing mechanism, for example, a protrusion is provided at the tip of the cam fixing shaft 243 of the exhaust camshaft 240, and a groove that can be fitted to the protrusion of the cam fixing shaft 243 in the through hole 220a of the cam driven sprocket 220. It may be realized by providing.

On the other hand, at the time of assembling, the intake camshaft 230 is positioned as follows while being held by the exhaust camshaft 240.

Here, from the other surface 220B side of the cam driven sprocket 220, a part of the fixing pins 23OA, 230B and the low-speed lock pin 217 protrude in the Y direction. The intake camshaft 230 has a fixed pin 230A inserted into the pin floating groove 233a, a fixed pin 230B inserted into the pin floating groove 233b, and a part of the low speed lock pin 217 inserted into the low speed pin introduction hole 233d. Positioned.

Thus, when the above assembly is completed, the intake camshaft 230 is limited by the rotating power low speed lock pin 217 and the low speed pin introduction hole 233d. As a result, the intake camshaft 230 is fixed to the cam driven sprocket 220 together with the exhaust camshaft 240 so as not to rotate.

[0125] A state where the valve timing control device 200 having the above configuration is attached to the engine 7 will be described.

FIG. 6 is a detailed sectional view of the cylinder head 7S taken along the line PP in FIG. 2 (b). In Fig. 6, 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. Note that the X, Y, and Z directions are defined in the same way in FIGS.

[0127] As shown in FIG. 6, a space for attaching the valve timing control device 200 is provided at the center of the cylinder head 7S. [0128] When the valve timing control device 200 is attached to the cylinder head 7S !, bearings Bl and B2 are attached to the rotating shaft 233 and the protruding shaft 244 of the valve timing control device 200, respectively.

[0129] Inside the cylinder head 7S, one end surface of the bearing B1 perpendicular to the Y-direction axis contacts the internal contact surface BH1 of the cylinder head 7S. Further, one end surface of the bearing B2 perpendicular to the Y-axis axis contacts the internal contact surface BH2 of the cylinder head 7S.

[0130] With the valve timing control device 200 housed inside the cylinder head 7S, a part of the other end surface of the bearing B1 perpendicular to the Y-direction axis is fixed to the fixed plate BH3 connected to the cylinder head 7S. Abut. Thereby, the valve timing control device 200 is fixed to be rotatable inside the cylinder head 7S.

[0131] Two roller rocker arms 330 and 340 are provided on the upper part of the valve timing control device 200. A roller rocker arm 330 is provided above the intake camshaft 230, and a roller 330T attached to the arm 330R is in contact with the intake camshaft 230.

[0132] Further, a roller rocker arm 340 is provided on the exhaust camshaft 240, and a roller 340T attached to the arm 340R is in contact with the exhaust camshaft 240. A side cover SC is attached to the cylinder head 7S so as to cover the lock pin holding mechanism 210 side of the valve timing control device 200.

FIG. 7 shows an external side view of the cylinder head 7S with the side cover SC of FIG. 6 removed. As shown in FIG. 7, a chain 25 is hung on the cam driven sprocket 220. In FIG. 7, the valve timing control device 200 rotates in the direction of arrow Q1.

FIG. 8 is a partially cutaway sectional view taken along line RR of cylinder head 7S in FIG. 6 and a diagram for explaining the phase relationship between intake cam 231 and exhaust cam 241.

FIG. 8 (a) shows a partially cutaway cross-sectional view taken along line RR of the cylinder head 7S of FIG. In Fig. 8 (a), the cross section around the intake and exhaust valves is shown as a cutout for easy understanding.

As shown in FIG. 8 (a), the roller rocker arm 33 provided on the upper portion of the intake cam 231 0 is composed of a roller 330T, an arm 330R, a shaft 331, an adjuster 332, and a nut 333 force.

[0137] The arm 330R extending in the X direction is rotatably held by the shaft 331 at the center thereof. A roller 330T is attached to one end of the arm 330R in the X direction, and an adjuster 332 is attached to the other end by a nut 333.

[0138] As the intake cam 231 rotates, the roller 330T moves up and down. As a result, the arm 330R rotates about the shaft 331. Thereby, the adjuster 332 at the other end of the arm 330R moves up and down.

[0139] The upper end of intake valve 334 is positioned at the lower end of adjuster 332. The intake valve 334 is provided with a valve spring 335, and the valve spring 335 biases the upper end portion of the intake valve 334 upward.

[0140] When the adjuster 332 moves up and down in this state, the intake valve 334 also moves up and down. As a result, the intake valve 334 is opened and closed.

[0141] In this way, the intake valve 334 receives the rotational force of the intake cam 231 from the roller rocker arm 3

Transmitted through 30. On the other hand, the elastic force of the valve spring 335 is transmitted to the intake cam 231 through one arm 330 of the roller rocker!

[0142] The roller rocker arm 340 provided on the upper portion of the exhaust cam 241 has the same configuration as the roller rocker arm 330 and performs the same operation. Roller rocker arm 340 mouth single roller 340T, arm 340R, shaft 341, adjuster 342 and nut 343 are equivalent to roller rocker arm 330 roller 330T, arm 330R, shaft 331, adjuster 332 and nut 333 respectively . The exhaust valve 344 is provided with a valve spring 345.

[0143] In FIG. 8, the valve timing control device 200 rotates in the direction of the arrow Q2.

In the present embodiment, the exhaust cam 2 is configured by the configuration of the valve timing control device 200 described above.

The phase of intake cam 231 with respect to the phase of 41 changes.

FIG. 8B shows a diagram for explaining the phase relationship between the intake cam 231 and the exhaust cam 241. To facilitate understanding, the exhaust cam 241 is shown by a thick solid line in FIG. 8 (b). The intake cam 231 is indicated by a thin solid line and a two-dot chain line. [0146] As shown by the solid line in Fig. 8 (b), when the engine 7 is low and rotates at the rotational speed, the tip of the cam nose of the intake force 231 is at the position T1. From this state, when the rotational speed of the engine 7 increases and exceeds a predetermined rotational speed, the tip of the cam nose of the intake cam 231 moves to the position T2. Hereinafter, the predetermined rotational speed when the rotational speed increases at a low value force is referred to as the first rotational speed.

On the other hand, as shown by the two-dot chain line in FIG. 8B, when the engine 7 is rotating at a high speed, the tip of the cam nose of the intake cam 231 is at the position T2. From this state, when the rotational speed of the engine 7 decreases and becomes lower than the predetermined rotational speed, the tip of the cam nose of the intake cam 231 moves to the position T1. Hereinafter, the predetermined rotational speed when the rotational speed falls from a high value is referred to as the second rotational speed.

Thus, in the present embodiment, the phase of intake cam 231 with respect to exhaust cam 241 changes in accordance with the rotation speed of engine 7 and changes in the rotation speed (increase and decrease in the rotation speed). In FIG. 8 (b), the amount of phase change of the intake cam 231 is represented by an angle Θ.

[0149] As described above, the valve timing differs between when the engine 7 is rotating at a low speed and when the engine 7 is rotating at a high speed. When the engine 7 is running at a low speed, the overlap between the opening and closing periods of the intake valve and the opening and closing of the exhaust valve is reduced, reducing harmful substances in the exhaust gas and improving fuel efficiency. To do. Further, when the engine 7 rotates at a high speed, the overlap between the period during which the intake valve is open and the period during which the exhaust valve is open becomes large, so a high output can be obtained efficiently.

[0150] The change in overlap caused by the change in the phase of the intake cam 231 with respect to the exhaust cam 241 will be described with reference to FIG. FIG. 9 is a diagram for explaining the relationship between the phase of the exhaust cam 241 and the intake cam 231 with respect to the crankshaft 23 in FIG. 2 and the lift amount of the exhaust valve 344 and the intake valve 334 when the crankshaft 23 rotates. FIG.

[0151] In FIG. 9, 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 344 and the intake valve 334 (the vertical direction of the exhaust valve 344 and the intake valve 334). Displacement).

In FIG. 9, the exhaust valve 344 and the intake valve 334 are open when the lift amount is larger than 0, and are closed when the lift amount force is ^. [0153] The crank angle is shown from one 360 ° to + 360 °. Piston 21 is located at top dead center TDC in cylinder 20 when crank angle is 0 °, 360 ° and — 360 °, and piston 21 is below cylinder 20 when crank angle is 180 ° and 180 ° Located at the dead center BDC.

[0154] A thick line 241L in Fig. 9 shows a change in the lift amount of the exhaust valve 344 due to the rotation of the exhaust cam 241. According to the thick line 241L, the lift angle of the exhaust valve 344 is about 1240. About—110. The crank angle decreases from about 110 ° to about 20 °.

A solid line TL1 in FIG. 9 shows a change in the lift amount of the intake valve 334 due to the intake cam 231 rotating when the engine 7 rotates at a low speed. According to the solid line TL1, the lift amount of the intake valve 334 increases when the crank angle increases by about 40 ° to about 170 ° and the crank angle increases by about 170 °. The power is decreasing.

Thus, when the engine 7 is running at a low speed, the amount of overlap between the period during which the intake valve 334 is open and the period during which the exhaust valve 344 is open is small. In the example of Fig. 9, the amount of overlap is 0.

On the other hand, a two-dot chain line TL2 in FIG. 9 shows a change in the lift amount of the intake valve 334 due to the intake cam 231 rotating when the engine 7 rotates at a high speed. According to the two-dot chain line TL2, the lift amount of the intake valve 334 increases when the crank angle increases by about 30 ° to about 100 ° and decreases by about 230 ° from about 100 ° force. .

Thus, when the engine 7 rotates at a high speed, the amount of overlap between the period during which the intake valve 334 is open and the period during which the exhaust valve 344 is open increases.

As described above, the phase of the intake cam 231 changes by the angle Θ with respect to the exhaust cam 241 between the low speed and the high speed of the engine 7, so that the period during which the exhaust valve 344 is open and the intake air The amount of overlap with the period in which the valve 334 is open changes, and the above-described effect can be obtained.

It should be noted that in the nove timing control apparatus 200 according to the present embodiment, as shown in FIG. 6, the length in the Y direction of lock pin holding mechanism 210 is relatively small. As a result, this valve timing control device 200 has a high degree of freedom of installation (degree of freedom of layout). , Has excellent versatility. Therefore, the nozzle timing control device 200 can be effectively used for engines having configurations other than those described above.

FIGS. 10 to 14 are cutaway perspective views for explaining the operation of the valve timing control device 200. FIG. 10 to 14, the valve timing control device 200 is shown with a part of the lock pin holding mechanism 210, the cam driven sprocket 220, and the intake camshaft 230 cut out.

In FIGS. 10 to 14, the direction indicated by the arrow Z is defined as the Z direction. In the Z direction, the direction in which the arrow is directed is the + direction, and the opposite direction is the one direction. Furthermore, the alternate long and short dash line in the figure indicates the axis J of the valve timing control device 200.

[0163] FIG. 10 shows a state when the assembly of the valve timing control device 200 is completed. In FIG. 10, the lock pin holding mechanism 210 and the cam driven sprocket 220 are also cut away along the Z direction in the central force. The fixing pin 230B is actually connected to the force driven sprocket 220 as described above.

As shown in FIG. 10, when the assembly of the valve timing control device 200 is completed, the weight main body 213a of the weight 213 is urged in the −Z direction by the spring S1. Here, the weight 213 holds the high-speed lock pin 214 inserted into the through hole 220b of the cam driven sprocket 220. Thereby, the rotation operation of the weight 213 around the rotation shaft 215 is restricted. In this state, a part of the high speed lock pin 214 comes into contact with the groove 213b of the weight 213.

On the other hand, the weight body 216a of the weight 216 is biased in the + Z direction by a spring S2 (not shown) (see FIG. 4). Here, the weight 216 holds the low speed lock pin 217 inserted into the through hole 220c of the cam driven sprocket 220. Thereby, the rotation operation of the weight 216 around the rotation shaft 218 is limited.

In FIG. 10, one end of the high-speed lock pin 214 inserted into the cam driven sprocket 220 is substantially in contact with the contact surface 230M perpendicular to the axis J of the intake camshaft 230.

On the other hand, the low speed lock pin 217 is inserted into the low speed pin introduction hole 233d of the intake camshaft 230. One end of the low-speed lock pin 217 inserted into the low-speed pin introduction hole 233d is the low-speed pin It almost abuts against the bottom surface of the introduction hole 233d.

[0168] As described above, the pin floating groove 233b extends along the circumferential direction around the axis J. Here, one end in the circumferential direction of the pin floating groove 233b is referred to as a low speed groove end LP, and the other end in the circumferential direction of the pin floating groove 233b is referred to as a high speed groove end HP.

In FIG. 10, the fixed pin 230B inserted into the pin floating groove 233b is located at the low speed groove end LP. Since the fixed pin 230B is fixed to the cam driven sprocket 220, the intake camshaft 230 is restricted from rotating in the direction of the arrow Ml with respect to the cam driven sprocket 220 and the exhaust camshaft 240.

However, in the state of FIG. 10, since the low-speed lock pin 217 is inserted into the low-speed pin introduction hole 233d, the intake camshaft 230 has the arrows Ml and the cam driven sprocket 220 and the exhaust force shaft 240. Cannot rotate in any direction of arrow M2.

FIG. 11 shows the state of the valve timing control device 200 at the time of low rotation.

At the time of low rotation of the valve timing control device 200, a weak distal force acts on the weights 213 and 216. As a result, a force is generated to rotate the weight body 213a about the rotation shaft 215 as indicated by a thick arrow M3. Further, as shown by the thick arrow M4, a force is generated to rotate the weight body 216a about the rotation shaft 218.

[0172] Here, when the weight body 216a rotates in the direction of the thick arrow M4, a force is generated to pull out the low-speed lock pin 217 held by the weight 216 from the low-speed pin introduction hole 233d of the intake camshaft 230 (arrow (See M6).

[0173] Here, at the time of low rotation, the spring S2 (not shown) urges the weight body 216a in the + Z direction, so that the elastic force of the spring S2 and the force acting in the direction of the thick arrow M4 Are balanced. As a result, the low speed lock pin 217 does not completely come out of the low speed pin introduction hole 233d.

On the other hand, when a force in the direction of the thick arrow M3 is generated in the weight main body 213a, a force in a direction in which the high-speed lock pin 214 holding the weight 213 force S approaches the intake camshaft 230 is generated (see arrow M5). However, the high-speed lock pin 214 does not move in the direction of the axis J because one end of the low-speed lock pin 217 is in contact with the contact surface 230M. As a result, the weight body 213a does not rotate either.

FIG. 12 and FIG. 13 show the state of the valve timing control device 200 when the engine 7 rotates at the first rotation speed due to the increase in the rotation speed of the engine 7.

As described above, a centrifugal force acts on the weights 213 and 216 when the valve timing control device 200 rotates. Here, when the rotational speed of the engine 7 increases from a low value to a high value, a large centrifugal force acts on the weights 213 and 216.

[0177] As a result, the force in the direction of the thick arrow M4 generated in the weight body 216a becomes larger than the elastic force of the spring S2 in Fig. 4, and the arrow M6 tries to pull out the low-speed lock pin 217 from the low-speed pin introduction hole 233d. The direction force also becomes larger.

[0178] As a result, as shown in FIG. 12, the rotation speed becomes the first rotation speed and the low-speed lock pin

217 is pulled out from the low speed pin introduction hole 233d. In this state, the force due to the centrifugal force of the weight 213 is generated in the high-speed lock pin 214 in the direction of the arrow M5.

[0179] As described above, when the low-speed lock pin 217 is pulled out from the low-speed pin introduction hole 233d, the intake camshaft 230 is allowed to rotate with respect to the cam driven sprocket 220 and the exhaust camshaft 240.

[0180] The fixing pin 230B inserted into the pin floating groove 233b is positioned at the low speed groove end LP while applying a force. Therefore, the intake camshaft 230 is allowed to rotate only in the direction of the arrow M2.

Here, as described with reference to FIG. 8, the elastic force of the valve spring 335 is transmitted to the intake cam 231 of the intake camshaft 230 via the roller rocker arm 330.

[0182] Thereby, the intake camshaft 230 generates a force for rotating the cam driven sprocket 220 and the exhaust camshaft 240 in the direction of the arrow Ml or the arrow M2.

[0183] The force for rotating intake camshaft 230 in the direction of arrow Ml or arrow M2 will be described with reference to FIG.

As shown in FIG. 8, the roller 330T of the roller rocker arm 330 contacts the upper end of the intake cam 231. In this case, the upper end portion of the intake cam 231 is urged downward by the inertial force of the valve spring 335. [0185] When the cam nose approaches the roller 330T when the intake cam 231 rotates in the direction of the arrow Q2, the force that pushes the intake cam 231 downward by the roller 330T. Rotates the intake cam 231 in the direction opposite to the arrow Q2. To work.

Similarly, when the cam nose moves away from the roller 330T when the intake cam 231 rotates in the direction of the arrow Q2, the force that pushes the intake cam 231 downward by the roller 330T. Work to rotate. In this example, the arrow Q2 in FIG. 8 corresponds to the arrow M2.

[0187] In the state shown in Fig. 12, the intake camshaft 230 is forced to rotate in the direction of the arrow M2 by the intake camshaft 230, so that the intake camshaft 230 is in the direction of the arrow M2 with respect to the cam driven sprocket 220 and the exhaust camshaft 240. Rotate in the direction.

As shown in FIG. 13, when the intake camshaft 230 rotates in the direction of the arrow M2, the pin floating groove 233b in which the fixed pin 230B is inserted also rotates about the axis J. Here, as described above, the pin floating groove 233b has the low speed groove end portion LP and the high speed groove end portion HP. Therefore, the rotation of the pin floating groove 233b in the direction of the arrow M2 is limited by the high speed groove end HP.

Thereby, the intake camshaft 230 is restricted from rotating in the direction of the arrow M2 because the fixed pin 230B is positioned at the high-speed groove end HP of the pin floating groove 233b.

Thus, when the fixed pin 230B is positioned at the high speed groove end HP of the pin floating groove 233b, the high speed pin introduction hole 233c communicates with the through hole 220b of the cam driven sprocket 220. As a result, the one end force of the high speed lock pin 214 that has been in contact with the contact surface 230M is inserted into the high speed pin introduction hole 233c by the centrifugal force acting on the weight 213 (see FIG. 14).

[0191] As the intake camshaft 230 rotates as described above, the phase of the intake cam 231 with respect to the exhaust cam 241 changes by an angle Θ. As a result, the valve timing of the engine 7 changes stably without being affected by the elastic force of the valve springs 335, 345.

[0192] The function of the pin floating groove 233a (see Fig. 4) not shown in Figs. 10 to 14 is not described, but the function of the pin floating groove 233a is the same as that of the pin floating groove 233b.

Further, in FIG. 13, the protrusion 220T in FIG. 3 is indicated by a broken line. This protrusion 220T is provided to limit the rotational movement of the weight body 216a around the rotation shaft 218. ing. For example, when the weight main body 216a rotates by a predetermined amount, one surface of the weight main body 216a comes into contact with the protrusion 220T. Accordingly, the weight main body 216a is largely rotated in the direction of the arrow M4, and the low speed lock pin 217 is prevented from coming out of the through hole 220c.

FIG. 14 shows a state of the valve timing control device 200 after the valve timing of the engine 7 is changed by the first rotational speed.

[0195] As described above, after the valve timing of the engine 7 at the first rotational speed changes, one end of the high-speed pin 214 is inserted into the high-speed pin introduction hole 233c. As a result, the intake camshaft 230 cannot rotate in either the direction of the arrow Ml or the arrow M2. Thereby, at the time of high rotation, the phase relationship between the intake cam 231 and the exhaust cam 241 is fixed with a phase relationship different from that at the time of low rotation.

[0196] On the other hand, when the engine 7 rotates at the second rotation speed due to the decrease in the rotation speed of the engine 7, an operation opposite to the above is performed.

That is, in FIG. 14, when the rotational speed of the engine 7 falls from a high value to the second rotational speed, the weight main body 213a rotates in the direction opposite to the thick arrow M3 by the elastic force of the spring S1. As a result, the high-speed lock pin 214 is pulled out of the high-speed pin introduction hole 233c of the intake camshaft 230.

Further, in FIG. 14, the weight main body 216a rotates in the direction opposite to the thick arrow M4 by the elastic force of the spring S2 (not shown) (see FIG. 4). As a result, one end of the low speed lock pin 217 is pressed against the contact surface 230M of the intake camshaft 230.

[0199] As described above, the intake camshaft 230 generates a force for rotating the cam driven sprocket 220 and the exhaust camshaft 240 in the direction of the arrow Ml or the arrow M2.

[0200] Thus, the intake cam shaft 230 rotates in the direction of the arrow Ml by the elastic force of the valve spring 335 acting on the intake cam 231. Therefore, the intake camshaft 230 is fixed by inserting the low-speed lock pin 217 into the low-speed pin introduction hole 233d of the intake camshaft 230. As a result, the valve timing of the engine 7 changes stably without being affected by the elastic force of the valve springs 335 and 345.

[0201] By the way, as described above, in the present embodiment, when the rotational speed of the engine 7 increases, The number of revolutions at which the valve timing changes differs depending on the number of drops. That is, the first rotational speed and the second rotational speed are different.

[0202] Here, the first rotation speed and the second rotation speed are realized by setting the constituent members of the valve timing control device 200. For example, the elastic forces of the spring S1 and the spring S2 are set to be different from each other. In this case, the force acting on the high-speed lock pin 214 held by the weight 213 is different from the force acting on the low-speed lock pin 217 held by the weight 216.

[0203] As a result, the rotation speed at which the high-speed lock pin 214 is extracted from the high-speed pin introduction hole 233c (second rotation speed) and the rotation speed at which the low-speed lock pin 217 is extracted from the low-speed pin introduction hole 233d (first rotation) The number of rotations is different.

[0204] Thus, the rotational speed at which the valve timing changes differs between when the rotational speed of the engine 7 increases and when the rotational speed decreases. Therefore, hunting in which the valve behavior becomes unstable due to the elastic force of the valve springs 335 and 345 when the valve timing changes is sufficiently prevented. As a result, cam profile changes due to hunting are prevented, and degradation of engine performance and durability is prevented.

[0205] As described above, in the present embodiment, the intake cam for the exhaust camshaft 240 is changed by changing the rotational speed of the engine 7 from a low rotational speed to a high rotational speed or a high rotational speed force to a low rotational speed. The phase of shaft 230 changes. Thereby, the valve timings of the exhaust valve 344 and the intake valve 334 are controlled in accordance with the rotational speed of the engine 7.

In the present embodiment, the phase of intake camshaft 230 with respect to exhaust camshaft 240 is switched without using friction force between the constituent members, and low-speed lock pin 217, low-speed pin introduction hole 233d, and high-speed lock This is based on mutually complementary movement of the pin 214 and the high-speed pin introduction hole 233c. As a result, there is almost no deterioration due to wear of components. As a result, the lifetime of the valve timing control device 200 can be extended without using wear-resistant components, and low cost can be realized.

[0207] Furthermore, the high-speed lock pin 214 and the high-speed pin introduction hole 233c and the high-speed lock pin 214 and the high-speed pin introduction hole 233c can be moved in a complementary manner with only a mechanical structure without requiring high machining accuracy. Therefore, manufacture becomes easy.

[0208] In addition, the low-speed lock pin 217, the low-speed pin introduction hole 233d, and the high-speed lock pin 214 In addition, since a control system including a hydraulic circuit, an electric circuit, software, and the like for controlling the moving operation of the high-speed pin introduction hole 233c is not required, the valve timing control device 200 can be downsized.

In addition, in the present embodiment, when the rotational speed of the engine 7 is increased, the phase of the intake camshaft 230 with respect to the exhaust camshaft 240 at the first rotational speed is controlled by the lock pin holding mechanism 210. Be changed. In this state, the opening / closing timing of the exhaust valve 344 and the intake valve 334 is controlled.

[0210] When the rotational speed of the engine 7 is lowered, the phase of the intake camshaft 230 with respect to the exhaust camshaft 240 is changed by the lock pin holding mechanism 210 at a second rotational speed lower than the first rotational speed. In this state, the opening / closing timing of the exhaust valve 344 and the intake valve 334 is controlled.

[0211] As described above, since the first rotational speed when the engine 7 is raised is different from the second rotational speed when the engine 7 is lowered, the rotational speed of the engine 7 is the first or second rotational speed. The phase of the intake camshaft 230 with respect to the exhaust camshaft 240 does not change repeatedly when continued in several regions. Thereby, hunting in which the behavior of the exhaust valve 344 and the intake valve 334 becomes unstable is sufficiently prevented.

[0212] (Other configuration examples)

In the present embodiment, the nove timing control device 200 is provided in the engine 7 having the SOHC (single over one head camshaft) structure. However, the engine 7 provided with the norebu timing control device 200 is The configuration is not limited as long as the camshaft is provided.

[0213] For example, the engine 7 may be an SV (side valve) engine, an OHV (overhead valve) engine, or a DOHC (double overhead camshaft) engine.

[0214] Also, as described with reference to FIG. 8, in the above, the noble timing control device 200 is the force valve timing control device 200 provided in the engine 7 including the single rocker arms 330 and 340. It may be provided in a hitting engine.

[0215] As described in FIGS. 10 to 14, the valve timing control device 200 includes the weight body 2 Springs SI and S2 are used to bias 13a and 216a in a predetermined direction. However, rubber or the like may be used instead of the springs S1, S2 as long as it is an elastic body that biases the weight bodies 213a, 216a in a predetermined direction.

[0216] Furthermore, in the present embodiment, the force described for the motorcycle as the vehicle is not limited to this, and the valve timing control device 200 is also provided in a small vehicle with a small displacement such as a tractor and a cart and an engine of a small vessel. be able to.

As described above, in the present embodiment, the engine 7 corresponds to the engine, the exhaust valve 344 corresponds to the first valve, the intake valve 334 corresponds to the second valve, and the valve timing control device 200 Corresponds to the valve timing control device, the cam driven sprocket 220 corresponds to the rotating member, the exhaust camshaft 240 corresponds to the first camshaft, the intake force shaft 230 corresponds to the second camshaft, The lock pin holding mechanism 210 corresponds to the phase change mechanism, the low speed lock pin 217 and the low speed pin introduction hole 233d correspond to the first locking mechanism, and the high speed lock pin 214 and the high speed pin introduction hole 233c correspond to the second lock mechanism. Corresponds to the locking mechanism

[0218] Further, the low-speed pin introduction hole 233d corresponds to the first locking portion, the low-speed lock pin 217 corresponds to the first locked member, and the spring S2 corresponds to the first biasing member, The weight body 216a corresponds to the first weight, the high-speed pin introduction hole 233c corresponds to the second locking portion, the high-speed lock pin 214 corresponds to the second locked member, and the spring S1 is the second locking member. It corresponds to a biasing member, and the weight body 213a corresponds to a second weight.

[0219] Furthermore, the low speed pin introduction hole 233d corresponds to the first hole, the low speed lock pin 217 corresponds to the first pin member, and the high speed pin introduction hole 233c corresponds to the second hole, The fixing pin 230A, 230B and the pin floating grooves 233a, 233b correspond to the restricting mechanism or blocking mechanism.

[0220] Furthermore, the pin floating grooves 233a and 233b correspond to the groove portions, the low speed groove end portion LP and the high speed groove end portion HP correspond to both end faces in the groove portion, and the fixing pins 230A and 230B correspond to the contact members. Engine 7 corresponds to the engine device, and motorcycle 100 corresponds to the vehicle.

In FIG. 8B, the phase of the intake cam 231 indicated by a solid line with respect to the exhaust cam 241 corresponds to the first phase, and the intake cam 231 indicated by a two-dot chain line with respect to the exhaust cam 241 Phase Corresponds to the second phase.

Industrial applicability

The present invention can be used for various vehicles and ships equipped with engines such as motorcycles and four-wheeled automobiles.

Claims

The scope of the claims

[1] A noble timing control device that controls the opening and closing timings of the first and second valves according to the engine speed,

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

A first camshaft provided to contact the first valve and opening and closing the first valve by rotating together with the rotating member;

A second camshaft that is in contact with the second valve and is rotatable relative to the first camshaft, and opens and closes the second valve by rotating together with the rotating member. When,

A phase change mechanism that changes the phase of the second camshaft with respect to the first camshaft to a first phase and a second phase;

The phase changing mechanism is

A first locking mechanism for locking the second camshaft in a state where the second camshaft has the first phase with respect to the first camshaft;

A second locking mechanism for locking the second camshaft in a state where the second camshaft has the second phase with respect to the first camshaft,

The first locking mechanism is urged in a direction to lock the second camshaft, and is provided to be movable in a direction to release the locking of the second camshaft by centrifugal force. And

The second locking mechanism is urged in a direction to release the locking of the second camshaft, and is provided so as to be movable in a direction to lock the second camshaft by centrifugal force. Valve timing control device.

[2] The first locking mechanism includes:

A first locking portion provided on the second camshaft;

A first locked member movably provided in a state of being locked to the first locking portion and a state of being released from the first locking portion;

A first biasing member that biases the first locked member in a direction to be locked by the first locking portion; A first weight that moves the first locked member in a direction away from the first locking member force by centrifugal force;

The second locking mechanism is

A second locking portion provided on the second camshaft;

A second locked member movably provided in a state of being locked to the second locking portion and a state of being detached from the second locking portion;

A second biasing member for biasing the second locked member in a direction away from the second locking portion;

A second weight for moving the second locked member in a direction locked by the second locking portion by centrifugal force;

The second camshaft is

The first camshaft is disengaged from the first locking portion and the second locked member is detached from the second locking portion with respect to the first camshaft. 2. The valve timing control device according to claim 1, wherein the valve timing control device is provided so as to be relatively rotatable between a first phase and the second phase.

[3] The first locking portion is a first hole provided in the second camshaft,

The first locked member is a first pin member movably provided in a state of being inserted into the first hole and a state of being pulled out of the first hole,

The second locking portion is a second hole provided in the second camshaft, and the second locked member is inserted into the second hole and 3. The valve timing control device according to claim 2, wherein the valve timing control device is a second pin member movably provided so as to be disengaged from the second hole.

[4] The phase change mechanism includes:

2. The valve timing according to claim 1, further comprising a restriction mechanism that restricts a rotational operation of the second camshaft relative to the first camshaft to a range between the first phase and the second phase. Control device.

[5] The regulation mechanism is:

Whether the phase of the second camshaft relative to the first camshaft is the first phase The rotation of the second camshaft is prevented when the second phase is changed to the second phase, and the phase of the second camshaft relative to the first camshaft is changed from the second phase to the first phase. 5. The valve timing control device according to claim 4, further comprising a blocking mechanism that blocks the rotation of the second camshaft when changed to.

[6] The blocking mechanism includes:

A groove provided along the circumferential direction in the second camshaft;

6. The valve timing control device according to claim 5, further comprising an abutting member fixed to the rotating member, movable in the groove portion and provided so as to be able to contact both end surfaces of the groove portion.

[7] an engine having first and second valves;

A valve timing control device that controls opening and closing timings of the first and second valves in accordance with the rotational speed of the engine,

The valve timing control device includes:

The phase changing mechanism is

The first locking mechanism is urged in a direction to lock the second camshaft, and is provided to be movable in a direction to release the locking of the second camshaft by centrifugal force. And The second locking mechanism is urged in a direction to release the locking of the second camshaft, and is provided so as to be movable in a direction to lock the second camshaft by centrifugal force. Engine device.

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 first and second valves;

The valve timing control device includes:

The phase changing mechanism is

The first locking mechanism is urged in a direction to lock the second camshaft, and is provided to be movable in a direction to release the locking of the second camshaft by centrifugal force. And The second locking mechanism is urged in a direction to release the locking of the second camshaft, and is provided so as to be movable in a direction to lock the second camshaft by centrifugal force. The vehicle.