JP5308888B2 - Variable valve gear - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an engine suitable for a saddle-ride type vehicle such as a motorcycle.

  Conventionally, in the control of the variable valve device, when the gear position sensor detects the neutral position of the transmission, the engine speed is increased without changing from the low speed cam to the medium high speed cam. Therefore, there is a technique for preventing the occurrence of a cam switching sound (for example, see Patent Document 1).

JP-A-4-303142

By the way, in the above conventional technique, whether or not the cam can be switched is controlled only depending on whether or not the transmission is in a neutral state. However, in a motorcycle or the like equipped with a manual clutch, the transmission is put in a low gear. There may be a situation where the clutch is disengaged and the vehicle is prepared for launch. In such a case, if the engine speed is increased and the engine speed is increased, the cam is switched to the middle / high speed side at the predetermined engine speed, causing the same problem as in the prior art. It is necessary to perform the same control.
However, when the vehicle is used in a race or the like, and in a situation where a so-called racing start is started in which a clutch is connected from a state where the engine is in a middle and high rotation range, such a situation of use is also applicable. Since the sound generated from the intake / exhaust system of the rotating engine is large, there is a need to obtain a high output according to the racing start by not switching the cam switching sound but rather switching to the medium / high speed cam.

  Accordingly, the present invention provides a variable valve system that switches between a low speed cam and a high speed cam according to the state of the vehicle, while prohibiting switching to a high speed cam in a low engine speed range, The purpose is to enable switching to the high-speed cam at the start of racing.

As a means for solving the above-mentioned problems, the invention described in claim 1 is a variable valve that switches between a low speed cam and a high speed cam of a variable valve mechanism (for example, the valve mechanism 5 of the embodiment) according to the state of the vehicle. In the apparatus, when it is determined that the engine (for example, the engine 1 of the embodiment) is in a no-load state and the vehicle speed detection means (for example, the vehicle speed sensor 91 of the embodiment) determines that the vehicle is in a stopped state, the throttle is opened. When the degree is smaller than the predetermined value, switching to the high-speed cam is prohibited, and when the throttle opening is greater than the predetermined value, the actual engine speed is compared to the engine speed at the same throttle opening when the engine is unloaded. while if it is determined the number is low, it is determined that the clutch is about to be connected, to allow switching to the high-speed cam at a predetermined engine speed, ene Than the engine speed at the same throttle opening in emissions unloaded state, when it is determined that the actual engine speed is high, it is determined that the clutch is not going to be connected, switching to high-speed side cams Is prohibited.
The invention described in claim 2 has the engine speed as a map of the standard engine speed with respect to the throttle opening in the no-load state of the engine, and when the throttle opening is a predetermined value or more, the standard of the actual engine speed. When the amount of decrease from the rotational speed exceeds a predetermined value, it is determined that the clutch is about to be engaged, and when the amount of decrease is less than the predetermined value, it is determined that the clutch is not about to be connected. It is characterized by doing.
The invention as set forth in claim 3, said a predetermined value for determining the magnitude of the throttle opening degree, and a predetermined value for determining the magnitude of the amount of decrease in engine rotational speed, and the value of the combination related to each other It is characterized by.
According to a fourth aspect of the present invention, when it is determined that the vehicle speed detecting means has failed, switching to the high speed cam at a predetermined engine speed is prohibited regardless of the throttle opening. It is characterized by.
According to a fifth aspect of the present invention, whether or not the engine is in a no-load state is determined by a neutral sensor (for example, the neutral sensor 94 of the embodiment), a gear position sensor, or a clutch sensor (for example, the clutch sensor 95 of the embodiment). It is determined by the neutral determination by

According to the first aspect of the present invention, in the low-rotation region where the throttle opening is small, the switching to the high-speed cam is prohibited to prevent the occurrence of a cam switching sound, while the throttle opening is In the case of a large high speed region, it is further determined whether or not the clutch is just before being connected based on the amount of decrease in engine speed, and if it is determined that the clutch is just before being connected, the engine speed is increased at a predetermined engine speed. By permitting switching to the side cam, it is possible to switch to the high speed side cam at the so-called racing start, obtain high output according to the racing start, and when it is judged that the clutch is not immediately before connection In this case, switching to the high-speed cam can be prohibited to prevent the cam switching sound.
According to the second aspect of the present invention, the reduction amount is obtained from the difference between the engine speeds at a predetermined timing, and the reduction amount is obtained using a conventional rotational speed detection means without using a special sensor. And the configuration and control of the variable valve operating apparatus can be simplified. Further, by determining whether or not the clutch is about to be engaged based on whether or not the amount of decrease in engine speed is greater than or equal to a predetermined value, it is possible to cope with this by changing the predetermined value according to the characteristics of the vehicle and the clutch. It can be applied to many models.
According to the third aspect of the present invention, when the predetermined value for determining the amount of decrease in the engine speed is changed according to the characteristics of the vehicle and the clutch, the predetermined value for determining the throttle opening is also changed. By doing so, it is possible to perform control more suitable for the characteristics.
According to the invention described in claim 4, since the cam switching which is a normal control is prohibited in a state where the vehicle speed cannot be detected, a neutral state may be included when the vehicle running state cannot be determined. Therefore, in such a case, the cam switching sound can be reliably suppressed by prohibiting the cam switching unconditionally.
According to the fifth aspect of the present invention, it is possible to reliably determine whether or not the engine is in the no-load state by the neutral determination by the neutral sensor, the gear position sensor, or the clutch sensor.

It is a left view of the engine in the Example of this invention. It is a top view of the principal part of the valve mechanism of the said engine, (a) shows the state in the operation position in a low speed side cam, (b) shows the state in the operation position in a high speed side cam, respectively. It is a block diagram of the variable valve apparatus containing the said valve mechanism. It is a flowchart which shows the principal part of the process in ECU of the said variable valve apparatus. It is a graph for process description when the said ECU calculates | requires the variation | change_quantity of the engine speed for every predetermined time. It is a map which shows the engine speed with respect to the throttle opening at the time of the engine no load which said ECU has. It is a table | surface which shows the combination of the predetermined value of the fall amount of the engine speed which said ECU has, and the predetermined value of throttle opening. It is a flowchart which shows the modification of the process in the said ECU. 1 is a left side view of a motorcycle according to an embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. For convenience of explanation, the arrow FR indicates the front, the arrow LH indicates the left side, and the arrow UP indicates the upper side.

  FIG. 9 is a right side view of a motorcycle (saddle-type vehicle) 101 provided with the variable valve operating apparatus of the present embodiment. A front wheel 102 of the motorcycle 101 is pivotally supported at lower ends of left and right front forks 103, and a front wheel suspension system 104 mainly including the left and right front forks 103 is pivotally supported by a head pipe 106 of a vehicle body frame 105. On the other hand, the rear wheel 107 of the motorcycle 101 is pivotally supported by the rear end portion of the rear swing arm 108, and the front end portion of the swing arm 108 can swing up and down on the left and right pivot plates 109 of the vehicle body frame 105 at the front and rear intermediate portions. Pivoted.

  From the head pipe 106, the left and right main tubes 111 extend rearwardly and rearwardly, and the rear ends of the left and right main tubes 111 are connected to the upper ends of the left and right pivot plates 109 at the front and rear intermediate portions of the vehicle body. The engine 1 is mounted below the left and right main tubes 111. The left and right engine hangers 112 extend downward from the front lower side of the left and right main tubes 111, and the front end of the engine 1 is supported by the lower ends of the left and right engine hangers 112. Note that the rear end portion of the engine 1 is supported appropriately above and below the left and right pivot plates 109.

  FIG. 1 is a left side view of an engine (internal combustion engine) 1 which is a prime mover of the motorcycle. The engine 1 is a parallel four-cylinder engine in which the rotation center axis (crank axis) of the crankshaft 10 is aligned in the vehicle width direction (left-right direction), and a cylinder 30 is tilted forward on the front upper side of the crankcase 20. It is erected in a posture (an inclined posture so that the upper part is located on the front side).

  Pistons 40 corresponding to the respective cylinders arranged along the crank axis are fitted in the cylinder 30 so as to be able to reciprocate, and the reciprocating motion of the pistons 40 is converted into rotational motion of the crankshaft 10 via the connecting rod 40a. Is done. A throttle body 48 is connected to the rear part of the cylinder 30, and an exhaust pipe 49 is connected to the front part of the cylinder 30.

  A transmission case 20a is integrally connected to the rear of the crankcase 20, a transmission (transmission) 29 is accommodated in the transmission case 20a, and a clutch 28 is accommodated in a right side portion of the transmission case 20a. The rotational power of the crankshaft 10 is output to the outside of the engine via the transmission 29.

  In the figure, reference numerals 30a, 2 and 3 denote a cylinder body, a cylinder head and a head cover in the cylinder 30, reference numeral 4 denotes a valve operating chamber formed by the cylinder head 2 and the head cover 3, and reference numeral 5 denotes a valve operating chamber 4. A valve mechanism for driving the intake / exhaust valves 6 and 7 accommodated therein, reference numerals 8 and 9 indicate intake / exhaust ports formed before and after the cylinder head 2, and reference numerals 11 and 12 indicate intake side and exhaust side camshafts. Respectively.

  The intake and exhaust ports 8 and 9 each form a pair of combustion chamber side openings for each cylinder, and the fuel chamber side openings are opened and closed by a pair of intake and exhaust valves 6 and 7, respectively. That is, the engine 1 is a four-valve type, and has a pair of left and right intake and exhaust valves 6 and 7 for each cylinder.

  The pair of left and right intake valves 6 for one cylinder are opened and closed by being pressed by the cam 11A of the intake camshaft 11 via an intake rocker arm 13 provided for each cylinder. Similarly, a pair of left and right exhaust valves 7 for one cylinder are opened and closed by being pressed by the cam 12A of the exhaust camshaft 12 via an exhaust rocker arm 17 provided for each cylinder.

  The intake-side rocker arm 13 is supported on an intake-side rocker arm shaft 14 disposed behind the stem tip of the intake valve 6 so as to be swingable about its axis and slidable in the axial direction. The exhaust-side rocker arm 17 is supported on an exhaust-side rocker arm shaft 18 disposed in front of the stem tip of the exhaust valve 7 so as to be swingable about its axis and slidable in the axial direction.

  When the engine 1 is in operation, the camshafts 11 and 12 are rotationally driven in conjunction with the crankshaft 10 to appropriately swing the rocker arms 13 and 17 according to the outer peripheral pattern of the cams 11A and 12A. The rocker arms 13 and 17 press the intake and exhaust valves 6 and 7, respectively, and the intake and exhaust valves 6 and 7 are appropriately reciprocated to open and close the fuel chamber side openings of the intake and exhaust ports 8 and 9, respectively.

  Here, the valve operating device 5 is configured as a variable valve operating device capable of changing the valve opening / closing timing and the lift amount of the valves 6 and 7. The valve gear 5 opens and closes the valves 6 and 7 using the cams for low-speed rotation in the camshafts 11 and 12 in the low-speed rotation range where the engine speed is less than 9000 rpm (Revolutions Per Minute), for example. In the high-speed rotation range where the rotation speed is 9000 rpm or more, the valves 6 and 7 are opened and closed using the high-speed rotation cams in the camshafts 11 and 12.

Hereinafter, the intake side for one cylinder in the valve operating mechanism 5 will be described as an example with reference to FIG. 2, but the intake side of other cylinders and the exhaust side of each cylinder also have the same configuration.
The cam 11A of the cam shaft 11 includes left and right first cams 15a and 16a for the low speed rotation region and left and right second cams 15b and 16b for the high speed rotation region. That is, the camshaft 11 has four cams in total, that is, left and right first cams 15a and 16a and left and right second cams 15b and 16b per cylinder.

  The rocker arm 13 is located at a limit position to the left in the direction along the axis C5 of the rocker arm shaft 14 (in the direction of the axis C5) when the engine 1 is stopped and operated in the low speed rotation range (FIG. 2A). In this state, the left and right cam sliding contact portions 13c of the rocker arm 13 are disposed below the left and right first cams 15a and 16a at positions where they can slide in contact with their outer peripheral surfaces (cam surfaces), respectively. The portion 13d is disposed at a position where the right end of the stem 13d can be pressed by the right side portion. At this time, the rocker arm 13 is swung by the left and right first cams 15a and 16a to open and close the intake valve 6.

  On the other hand, the rocker arm 13 is in the limit position of the rightward movement in the direction of the axis C5 when the engine 1 is operated in the high-speed rotation region (see FIG. 2B). The slidable contact portion 13c is disposed below the left and right second cams 15b and 16b at a position where the slidable contact portion 13c can be slidably contacted with the outer peripheral surface (cam surface). It arrange | positions in the position which can press a stem front-end | tip part. At this time, the rocker arm 13 is swung by the left and right second cams 15b and 16b to open and close the intake valve 6.

  Referring also to FIG. 3, the rocker arm 13 is moved in the axial direction (cam switching), for example, a rocker arm moving mechanism and a rocker arm movement restricting mechanism (not shown), and a hydraulic head disposed on the right side of the cylinder head 2. This is performed by the cooperation of the actuators 85. That is, in a state where the movement restriction mechanism restricts the movement of the rocker arm 13 in the direction of the axis C5, the rocker arm shaft 14 is moved in the direction of the axis C5, and the force necessary for the movement of the rocker arm 13 is applied to the movement mechanism. After the accumulation, the movement restriction of the rocker arm 13 is released, and the rocker arm 13 is moved in the direction of the axis C5 to switch the cam used for the operation.

  In the figure, reference numerals 72 to 77 denote an oil pump, a relief valve, an oil filter, a main oil gallery, a hydraulic pressure sensor, and an oil temperature sensor, respectively, and reference numeral 79 denotes a spool valve 81 from the main oil gallery 75 to a spool valve 81 before the actuator 85. Reference numeral 82 denotes an oil passage extending from the spool valve 81 toward each oil chamber on both sides of the hydraulic cylinder 86 of the actuator 85, and reference numeral 84 denotes a return oil path from the spool valve 81 to the oil pan 71. Each is shown.

  The spool valve 81 is controlled by an ECU 78 that controls the operation of the entire engine 1 and is used for opening and closing the valves 6 and 7 in accordance with the state of the vehicle (vehicle speed, engine speed (Ne), gear position, etc.). Switch the hydraulic path to switch.

  As shown in FIG. 3, the ECU 78 includes vehicle speed information from the vehicle speed sensor 91, throttle opening information from the throttle sensor 92, crank speed (engine speed) information from the crank sensor 93, and a neutral sensor 94 or clutch. Neutral information from the sensor 95 is input.

  Here, referring also to FIG. 9, the vehicle speed sensor 91 is provided, for example, on the front wheel 102 to detect its rotational speed, and the throttle sensor 92 is provided, for example, to the throttle body 48 to detect the rotation angle of the throttle valve. For example, the crank sensor 93 is provided in the crankcase 20 to detect the rotational speed of the crankshaft 10, and the neutral sensor 94 is provided in the mission case 20a to detect the rotational position of the shift drum or the like. The clutch sensor 95 is provided, for example, in a holder of the clutch lever 114 on the left side of the handle 104a of the front wheel suspension system 104 and detects the operating angle of the clutch lever 114. These sensors 91 to 95 are electrically connected to an ECU 78 mounted on the vehicle body frame 105, for example, behind the head pipe 106.

  The neutral sensor 94 detects whether or not the transmission of the engine 1 is in a neutral state. It should be noted that a neutral position may be detected by a gear position sensor (not shown) instead of the neutral sensor 94. The clutch sensor 95 detects whether or not the clutch lever 114 is operated and the clutch 28 is disengaged.

In the ECU 78, as shown in FIG. 4, control for determining (determining) permission or prohibition of cam switching of the valve mechanism 5 is performed based on the engine load, the vehicle speed, the throttle opening, and the engine speed.
That is, first, in step S1, it is determined whether or not the engine 1 is unloaded. When the neutral sensor 94 is ON or the clutch sensor 95 is OFF, it is determined that the engine 1 is in a neutral state, and thus the engine 1 is determined to be in a no-load state.

  Next, in step S2, it is determined whether or not the vehicle speed sensor 91 has failed. When this determination result is NO (when the vehicle speed sensor 91 is normal), the process proceeds to step S3 to determine whether or not the vehicle speed is equal to or less than a predetermined value set in advance. When the determination result is YES (when the vehicle speed is a predetermined value or less), it is determined that the vehicle is stopped or traveling at a low speed, and it is determined whether or not the racing start is performed after step S4. Do. If the predetermined value in step S3 is 0, it can be determined whether or not the vehicle is stopped.

If the determination result in step S3 is NO (when the vehicle speed exceeds a predetermined value), the process proceeds to step S6 and shifts to a normal cam switching routine. That is, for example, it is determined that the vehicle is traveling at medium / high speed, and normal cam switching control is performed according to the engine speed.
On the other hand, if the decision result in the step S2 is YES (when the vehicle speed sensor 91 has failed), the process proceeds to a step S7 to turn off the cam switching output. In this case, since the vehicle running state cannot be determined, the neutral state may be included, so the cam switching is unconditionally suppressed and the cam switching sound is reliably generated. I try to suppress it.

  If the determination result in step S3 is YES and the determination result in step S4 is YES (if the throttle opening is greater than or equal to a predetermined value), the process proceeds to step S5, where the engine speed is equal to or less than a predetermined value set in advance. It is determined whether or not. If the result of this determination is YES (when the engine speed is less than or equal to a predetermined value), it is determined that it is a so-called racing start in which clutch meet is performed with the throttle opening being greater than or equal to a predetermined value and the engine speed being increased. In step S6, the normal cam switching routine is maintained. That is, it is possible to switch to the high speed cam at the so-called racing start, and to obtain a high output corresponding to the racing start.

On the other hand, if the determination result in step S5 is NO (when the engine speed exceeds a predetermined value), it is determined that the vehicle is not at the start of racing and the vehicle starts normally, and the process proceeds to step S7, where the cam switching output is turned off. Thus, the cam switching sound is prevented.
In addition, also when the determination result of step S4 is NO (when the throttle opening is less than a predetermined value), the process proceeds to step S7, where it is determined that the normal start is being performed, and the cam switching output is turned OFF.

Referring to FIG. 5, ECU 78 detects from a detection signal of the crank sensor 93 and the engine rotational speed at predetermined time intervals t, when subtracting the engine rotational speed Ne _n-1 of the previous from the most recent engine speed Ne _n with the difference? Ne _n, obtains the engine speed change amount for each predetermined time. ? Ne _n, if a positive value indicates an increase amount when the engine speed is increased with time, indicating a reduction amount when the engine speed decreases with time as long as a negative value.

Referring to FIG. 6, ECU 78 has an engine speed (hereinafter referred to as a standard speed) with respect to the throttle opening as a map when engine 1 is not loaded (for example, in a neutral state).
ECU78, the in step S4, it is judged whether or not a predetermined value Th ₀ or the throttle opening is set in advance. When the throttle opening is a value Th ₁ larger than the predetermined value Th ₀ , the actual engine speed Ne ₁ ′ at that time is equal to the standard speed Ne ₁ corresponding to the same throttle opening Th _1. It is determined whether it is low by comparison. In this case, as in the modification described below, by subtracting the actual engine speed Ne 1 _'from the standard rotation speed Ne ₁ corresponding to the same throttle opening Th ₁ difference? Ne is smaller predetermined value? Ne ₀ or a preset Or not (whether it is greatly reduced by a predetermined value ΔNe ₀ or more, whether it is Ne ₁ ′ or less, which is smaller than the standard rotation speed Ne ₁ by a predetermined value ΔNe ₀ ). This determination is the? Ne _n corresponds to the determination of whether or not a predetermined value? Ne ₀ or less.
If the determination result is YES, it is determined that it is a so-called racing start time in which the throttle is opened wide and the clutch 28 is engaged in a shorter time than when starting normally.

The amount of decrease in the engine speed at the time of clutch meet varies depending on the vehicle type, engine displacement, clutch characteristics, etc., but a plurality of values ΔNe indicating the predetermined value of the amount of decrease in engine speed to correspond to these. _{.., And} a plurality of values Th _{0a, b, c} ... Indicating the predetermined value of the throttle opening are associated and combined (see FIG. 7), and the engine speed is changed according to the model. By changing the predetermined value of the decrease amount and the predetermined value of the throttle opening together, it is possible to easily set control suitable for the characteristics among a plurality of types of vehicles and engines.

FIG. 8 shows a modification of the cam switching control process performed by the ECU 78. This modification is different only in that step S5 ′ is provided instead of step S5 of the process shown in FIG.
That is, in step S5 ', the whether the decrease amount? Ne _n of engine speed is less than a preset predetermined value (whether large negative) determines. If the determination result is YES (when the decrease amount? Ne _n is less than a predetermined value), the process proceeds to step S6 it is determined that the a time racing start, maintain normal cam switching routine.
On the other hand, if the decision result in the step S5 'is NO (if reduction amount? Ne _n exceeds a predetermined value), it is determined that the normal starting is not a racing start, the process proceeds to step S7, the cam switching output To prevent the cam switching sound from being generated.

  As described above, the variable valve operating apparatus in the above embodiment switches the low speed side cam and the high speed side cam of the variable valve mechanism 5 according to the state of the vehicle, and the engine 1 is in a no-load state. When the vehicle speed sensor 91 determines that the vehicle is stopped, switching to the high speed cam is prohibited when the throttle opening is smaller than a predetermined value, and when the throttle opening is greater than the predetermined value, the engine If it is determined that the actual engine speed is lower than the engine speed at the same throttle opening in the no-load state, it is determined that the clutch is about to be engaged, and the engine speed is high at the predetermined engine speed. While switching to the side cam is permitted, switching to the high-speed side cam is prohibited when it is determined that the clutch is not being connected. That.

  According to this configuration, in the low rotation region where the throttle opening is small, the switching to the high-speed cam is prohibited to prevent the occurrence of cam switching noise, while in the high rotation region where the throttle opening is large. In this case, it is further determined whether or not the clutch is immediately before the connection based on the amount of decrease in the engine speed. If it is determined that the clutch is immediately before the connection, switching to the high-speed cam at the predetermined engine speed is performed. Can be switched to the high-speed cam at the so-called racing start, high output according to the racing start can be obtained, and if it is determined that the clutch is not immediately before connection, the high-speed side cam Switching to the cam can be prohibited to prevent the occurrence of a cam switching sound. This effect is particularly suitable for saddle riding type vehicles such as motorcycles whose engines are exposed to the outside of the vehicle and are often used for sports running.

In the variable valve system, the actual engine speed is detected at a predetermined timing, and the amount of decrease in the engine speed is calculated based on the difference between the engine speed detected this time and the engine speed detected last time. If the amount of decrease in the engine speed is equal to or greater than a predetermined value, it is determined that the clutch is about to be engaged, and if it is smaller than the predetermined value, it is determined that the clutch is not about to be connected. It is.
According to this configuration, by obtaining the amount of decrease from the difference in engine speed at a predetermined timing, it is possible to calculate the amount of decrease using a conventional speed detecting means without using a special sensor. The configuration and control of the variable valve device can be simplified. Further, by determining whether or not the clutch is about to be engaged based on whether or not the amount of decrease in engine speed is greater than or equal to a predetermined value, it is possible to cope with this by changing the predetermined value according to the characteristics of the vehicle and the clutch. It can be applied to many models.

In the variable valve apparatus, a predetermined value for determining the magnitude of the throttle opening and a predetermined value for determining the amount of decrease in the engine speed are combined values that are associated with each other.
According to this configuration, when changing the predetermined value for determining the amount of decrease in the engine speed according to the characteristics of the vehicle and the clutch, by changing the predetermined value for determining the magnitude of the throttle opening, It is possible to perform control more suitable for the characteristics.

In addition, the variable valve device prohibits switching to the high-speed cam at a predetermined engine speed regardless of the throttle opening when it is determined that the vehicle speed sensor 91 has failed. is there.
According to this configuration, since the cam switching that is a normal control is prohibited in a state where the vehicle speed cannot be detected, a neutral state may be included when the vehicle running state cannot be determined. In such a case, it is possible to reliably suppress the occurrence of a cam switching sound by prohibiting cam switching unconditionally.

In the variable valve operating apparatus, whether or not the engine 1 is in a no-load state is determined by a neutral determination by a neutral sensor 94, a gear position sensor, or a clutch sensor 95.
According to this configuration, it is possible to reliably determine whether or not the engine is in the no-load state by the neutral determination by the neutral sensor 94, the gear position sensor, or the clutch sensor 95.

The present invention is not limited to the above-described embodiment. For example, a parallel multiple cylinder engine other than four cylinders, a V-type or horizontally opposed multi-cylinder engine, a single-cylinder engine, and a crankshaft are arranged in the vehicle longitudinal direction. The present invention may be applied to various types of reciprocating engines such as vertical engines. Further, the present invention can be applied not only to the variable valve mechanism 5 having the above-described configuration but also to a variable valve apparatus having various variable valve mechanisms.
The configuration in the above embodiment is an example of the present invention and can be applied not only to a motorcycle but also to a three-wheeled or four-wheeled saddle-ride type vehicle, and various modifications can be made without departing from the gist of the present invention. Needless to say.

1 Engine 5 Valve mechanism (Variable valve mechanism)
91 Vehicle speed sensor (vehicle speed detection means)
92 Throttle sensor 93 Crank sensor 94 Neutral sensor 95 Clutch sensor

Claims (5)

In a variable valve operating apparatus that switches between a low speed side cam and a high speed side cam of a variable valve mechanism according to the state of the vehicle,
When it is determined that the engine is in a no-load state and the vehicle is detected by the vehicle speed detection means,
When the throttle opening is smaller than the predetermined value, switching to the high-speed cam is prohibited,
When the throttle opening is greater than or equal to the predetermined value,
If it is determined that the actual engine speed is lower than the engine speed at the same throttle opening in the engine-no-load state, it is determined that the clutch is about to be engaged, and at a predetermined engine speed While switching to the high-speed cam is allowed,
Than the engine speed at the same throttle opening in the engine no-load state, when it is determined that the actual engine speed is high, it is determined that the clutch is not going to be connected, switching to high-speed side cams A variable valve operating device characterized in that The engine speed with respect to the throttle opening in the engine no-load state has as a map of the standard speed,
When the throttle opening is greater than or equal to a predetermined value,
When the amount of decrease in the actual engine speed from the standard speed is equal to or greater than a predetermined value, it is determined that the clutch is about to be engaged,
2. The variable valve operating apparatus according to claim 1, wherein when the decrease amount is smaller than a predetermined value, it is determined that the clutch is not about to be engaged. Wherein the predetermined value for determining the magnitude of the throttle opening degree, and a predetermined value for determining the magnitude of the amount of decrease in engine speed, to claim 2, characterized in that the value of the combination related to each other Variable valve gear.   4. If the vehicle speed detecting means is judged to have failed, switching to a high speed cam at a predetermined engine speed is prohibited regardless of the magnitude of the throttle opening. The variable valve operating apparatus according to any one of the above.   5. The variable motion according to claim 1, wherein whether or not the engine is in a no-load state is determined by a neutral determination by a neutral sensor, a gear position sensor, or a clutch sensor. Valve device.

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