CN113550806B - Variable valve actuating mechanism for motorcycle engine with double overhead camshafts - Google Patents
Variable valve actuating mechanism for motorcycle engine with double overhead camshafts Download PDFInfo
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- CN113550806B CN113550806B CN202110912336.5A CN202110912336A CN113550806B CN 113550806 B CN113550806 B CN 113550806B CN 202110912336 A CN202110912336 A CN 202110912336A CN 113550806 B CN113550806 B CN 113550806B
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- air inlet
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- speed
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
- F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
- F01L13/0036—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
- F01L1/053—Camshafts overhead type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
- F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
- F01L1/348—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear by means acting on timing belts or chains
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
- F01L1/053—Camshafts overhead type
- F01L2001/0537—Double overhead camshafts [DOHC]
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Valve Device For Special Equipments (AREA)
Abstract
The present invention provides a variable valve gear for a motorcycle engine having a dual overhead camshaft, comprising: the high-speed air inlet cam is arranged between the low-speed air inlet cam and a front cam shaft gland, a friction spring is arranged between the high-speed air inlet cam and the front cam shaft gland, an axial key groove C is formed in the tail end of the air inlet cam shaft, a movable middle push rod is arranged in the key groove C, and the head end of the middle push rod is abutted to the synchronous bolt. The invention is suitable for the motorcycle engine with double overhead camshaft, can realize the change of the gas distribution phase of the engine in two working conditions of high speed and low speed to make the engine exert the best performance, the structure of the invention has high control precision, the space arrangement is compact, and the sound of the synchronous bolt during operation is effectively eliminated.
Description
Technical Field
The invention relates to the technology of motorcycle engines, in particular to a variable valve actuating mechanism of an engine, and particularly relates to a variable valve actuating mechanism for a motorcycle engine with a double overhead camshaft.
Background
When the engine is in two different working conditions of high speed and low speed, the synchronization and separation of the high speed intake cam and the low speed intake cam are controlled by the synchronous bolt to change the Valve Timing (Valve Lift and Valve overlap angle) so as to make the engine exert the best performance under different working conditions.
A variable gas distribution phase structure of a single cylinder engine of a motorcycle mainly adopts a single camshaft (a high-speed gas inlet cam, a low-speed gas inlet cam and a gas outlet cam are arranged on a single shaft) and is matched with a double gas inlet rocker arm assembly to be in a bolt (hole-shaft) synchronous mode, when the engine is in a low-speed working condition (the rotating speed of the engine does not meet the design requirement), the double gas inlet rocker arms respectively work (a rocker arm matched with the low-speed gas inlet cam drives a valve to suck gas, the other gas inlet rocker arm is matched with the high-speed gas inlet cam and only does a rotary action, and no action is carried out on the valve), and at the moment, the lift range of the engine valve is low, and the valve overlap angle is small; when the engine is in a high-speed working condition (when the rotating speed of the engine reaches a design required value), the bolt is pushed into the pin hole of the double air inlet rocker arm by the electromagnet, the two air inlet rocker arms realize synchronization, the double air inlet rocker arms move by a high-speed cam profile of the cam shaft to drive the air inlet valve to suck air, and the engine has high valve lift and large valve overlap angle.
At present, the motorcycle industry tends to be more and more towards large exhaust quantity and fine control, so that a double overhead camshaft (an intake cam and an exhaust cam are not arranged on the same shaft) becomes a mainstream, at the moment, the space is enlarged and the precision of a cam control rocker arm is reduced due to the fact that the double intake rocker arm variable valve timing structure originally applied to a single camshaft is simply carried out, therefore, the double intake rocker arm variable valve timing structure originally applied to the single camshaft is not suitable for a double overhead camshaft type or a multi overhead camshaft type, and a new variable valve timing mechanism is needed to be designed in an overhead mode.
Disclosure of Invention
The invention aims to provide a variable valve actuating mechanism for a motorcycle engine with double overhead camshafts, which is characterized in that an air inlet camshaft and an air outlet camshaft are arranged in an engine cylinder head, two independent air inlet cams, namely a high-speed air inlet cam and a low-speed air inlet cam, are arranged on the air inlet camshaft, wherein the high-speed air inlet cam is arranged on one side of the end surface of the low-speed air inlet cam and can rotate along with the low-speed air inlet cam, and the high-speed air inlet cam and the low-speed air inlet cam are separated and synchronized through a synchronous bolt, so that different cams are controlled to drive an air inlet rocker arm assembly, and the valve actuating phase of the engine can be changed to enable the engine to exert the best performance under two working conditions of high speed and low speed.
In order to achieve the purpose, the invention adopts the following technical scheme:
a variable valve train for a motorcycle engine having a dual overhead camshaft, comprising: a cylinder head, an exhaust camshaft, an exhaust rocker arm, an intake camshaft, a low-speed intake cam, a high-speed intake cam, an intake rocker arm and an electromagnet,
the exhaust camshaft and the intake camshaft are arranged in parallel inside the cylinder head, the head ends of the exhaust camshaft and the intake camshaft are fixed on one side inside the cylinder head through a camshaft front gland, the tail ends of the exhaust camshaft and the intake camshaft are fixed on the other side inside the cylinder head through a camshaft rear gland, an exhaust cam is arranged on the exhaust camshaft and used for driving an exhaust rocker arm, and a low-speed intake cam and a high-speed intake cam are sleeved on the intake camshaft and used for driving an intake rocker arm; the exhaust rocker arm is arranged on one side, provided with an exhaust cam shaft, in the cylinder head, and the intake rocker arm is arranged on one side, provided with an intake cam shaft, in the cylinder head;
the high-speed air inlet cam is arranged between the low-speed air inlet cam and the front gland of the camshaft, a friction spring is arranged between the high-speed air inlet cam and the front gland of the camshaft, and the friction spring is sleeved on the air inlet camshaft and used for pressing the high-speed air inlet cam on the end face of the low-speed air inlet cam; the end surface of the high-speed air inlet cam adjacent to the low-speed air inlet cam is provided with a blind hole;
an axial through hole is formed in the low-speed air inlet cam, a synchronous bolt is arranged in the through hole, the head end of the synchronous bolt is matched with the blind hole of the high-speed air inlet cam, a synchronous spring is arranged between the tail end of the synchronous bolt and the low-speed air inlet cam, and the synchronous spring is sleeved on the synchronous bolt and used for resetting the synchronous bolt;
the tail end of the air inlet cam shaft is provided with an axial key groove C, a movable middle push rod is arranged in the key groove C, the head end of the middle push rod is abutted against the synchronous bolt, and the tail end of the middle push rod penetrates through the tail end face of the air inlet cam shaft and is positioned outside the tail end of the air inlet cam shaft; a reset spring is arranged between the air inlet camshaft and the tail end of the middle push rod, and the reset spring is sleeved on the middle push rod and used for resetting the middle push rod;
the electromagnet is arranged on the outer side wall of the cylinder head and located at the tail end of the air inlet cam shaft, an electromagnet push rod is arranged between the electromagnet and the air inlet cam shaft, the electromagnet push rod is arranged in the side wall of the cylinder head, one end of the electromagnet push rod is driven by the electromagnet, and the other end of the electromagnet push rod is abutted to the tail end of the middle push rod.
The whole tertiary step axle construction that is coaxial setting of camshaft that admits air, its third step axle that includes the first step axle of head end, the second step axle at middle part, afterbody, the diameter of second step axle is greater than first step axle, the low-speed setting of admitting air the cam admits air admit.
The air inlet camshaft is also sleeved with a positioning sleeve A, the positioning sleeve A is positioned in the front gland of the camshaft, and the positioning sleeve A is in interference fit with the air inlet camshaft and has the function of limiting the axial degree of freedom of the air inlet camshaft through the front gland of the camshaft; the friction spring is sleeved on the positioning sleeve A, the two ends of the friction spring are respectively provided with a gasket A, one gasket A is sleeved in the middle of the positioning sleeve A and is abutted against the outer wall of the front gland of the camshaft, and the other gasket A is sleeved on the intake camshaft and is positioned between the friction spring and the high-speed intake cam.
The end face of the tail end of the air inlet camshaft is provided with a gasket B, the middle push rod penetrates through the middle of the gasket B, and the reset spring is located between the gasket B and the tail end of the middle push rod.
The head ends of the exhaust camshaft and the intake camshaft are respectively connected with a timing driven sprocket, and the timing driven sprocket is driven by an engine and respectively drives the intake camshaft and the exhaust camshaft to rotate.
A positioning sleeve B is arranged in the side wall of the cylinder head, and the electromagnet push rod is arranged in the side wall of the cylinder head through the positioning sleeve B; and an oil seal is arranged between the positioning sleeve B and the electromagnet, and the oil seal is sleeved on the electromagnet push rod and used for sealing the electromagnet push rod and preventing engine oil in the engine from flowing out of the electromagnet push rod.
The axis of the electromagnet push rod is coaxial with the end face of the tail end of the air inlet cam shaft; the middle push rod is a cylindrical straight rod with the radius R, the middle part and the head end of the middle push rod are both positioned in the rear gland of the camshaft, the radius of the tail end face of the air inlet camshaft is set to be R, the axial distance from the axis of the middle push rod to the tail end face of the air inlet camshaft is set to be D, and R + R is greater than D and R-R is greater than R-R; and a circular boss is arranged on the outer circular surface of the tail end of the middle push rod and is abutted against the electromagnet push rod.
The invention has the beneficial effects that: the invention arranges the air inlet cam shaft and the air outlet cam shaft in the engine cylinder head, wherein the air inlet cam shaft is arranged with two independent air inlet cams which are a high-speed air inlet cam and a low-speed air inlet cam, wherein the high-speed air inlet cam is arranged at one side of the end surface of the low-speed air inlet cam and can rotate along with the low-speed air inlet cam, and the high-speed air inlet cam and the low-speed air inlet cam are separated and synchronized through a synchronous bolt, so that different cams are controlled to drive the air inlet rocker arm component, and the engine can change the air distribution phase to enable the engine to play the best performance under two working conditions of high speed and low speed.
Drawings
FIG. 1 is a schematic assembly of the present invention;
FIG. 2 is an assembled oblique view of the present invention;
FIG. 3 is an assembled elevation view of an intake side variable valve timing structure;
FIG. 4 is a schematic diagram of the variable valve timing mechanism operating at low speed;
FIG. 5 is a schematic diagram of a variable valve actuation mechanism operating at high speed;
fig. 6 is a perspective view of the intake rocker arm.
Fig. 7 is a schematic perspective view of the high-speed intake cam and the camshaft.
In the figure: 1. the engine comprises a cylinder head, 2, a camshaft front gland, 3, an exhaust camshaft, 4, gaskets A, 5, a friction spring, 6, a high-speed intake cam, 7, a low-speed intake cam, 8, a synchronous spring, 9, a synchronous bolt, 10, a camshaft rear gland, 11, gaskets B, 12, a return spring, 13, an intermediate push rod, 14, a locating sleeve B, 15, an oil seal, 16, an electromagnet, 17, a timing driven sprocket, 18, a locating sleeve A, 19, an exhaust rocker arm, 20, a valve spring, 21, an exhaust valve, 22, an intake valve, 23, an intake rocker arm, 24, an electromagnet push rod, 25, an intake camshaft, 231, a shaft hole, 232, a driving wheel, 251, a first step shaft, 252, a second step shaft, 253, a third step shaft, 254, a key groove A, 255, a key groove C, 601, a blind hole, a through hole.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1 to 7, a variable valve gear for a motorcycle engine having a dual overhead camshaft includes: a cylinder head 1, an exhaust camshaft 3, an exhaust rocker arm 19, an intake camshaft 25, a low-speed intake cam 7, a high-speed intake cam 6, an intake rocker arm 23 and an electromagnet 16,
the exhaust camshaft 3 and the intake camshaft 25 are arranged in parallel inside the cylinder head 1, the head ends of the exhaust camshaft 3 and the intake camshaft 25 are fixed on one side inside the cylinder head 1 through a camshaft front gland 2, the tail ends of the exhaust camshaft 3 and the intake camshaft 25 are fixed on the other side inside the cylinder head 1 through a camshaft rear gland 10, an exhaust cam is arranged on the exhaust camshaft 3 and used for driving an exhaust rocker arm 19, and a low-speed intake cam 7 and a high-speed intake cam 6 are sleeved on the intake camshaft 25 and used for driving an intake rocker arm 23; the exhaust rocker arm 19 is arranged at one side of the cylinder head 1, which is provided with the exhaust camshaft 3, and the intake rocker arm 23 is arranged at one side of the cylinder head 1, which is provided with the intake camshaft 25;
the high-speed air inlet cam 6 is arranged between the low-speed air inlet cam 7 and the front camshaft gland 2, the friction spring 5 is arranged between the high-speed air inlet cam 6 and the front camshaft gland 2, and the friction spring 5 is sleeved on the air inlet camshaft 25 and used for pressing the high-speed air inlet cam 6 on the end face of the low-speed air inlet cam 7; the end surface of the high-speed air inlet cam 6 adjacent to the low-speed air inlet cam 7 is provided with a blind hole 601;
an axial through hole 701 is formed in the low-speed air inlet cam 7, a synchronous bolt 9 is arranged in the through hole 701, the head end of the synchronous bolt 9 is matched with the blind hole 601 of the high-speed air inlet cam 6, a synchronous spring 8 is arranged between the tail end of the synchronous bolt 9 and the low-speed air inlet cam 7, and the synchronous spring 8 is sleeved on the synchronous bolt 9 and used for resetting the synchronous bolt 9;
the tail end of the air inlet cam shaft 25 is provided with an axial key groove C255, a movable middle push rod 13 is arranged in the key groove C255, the head end of the middle push rod 13 is abutted against the synchronous bolt 9, and the tail end of the middle push rod 13 penetrates through the tail end face of the air inlet cam shaft 25 and is positioned outside the tail end of the air inlet cam shaft 25; a return spring 12 is arranged between the air inlet camshaft 25 and the tail end of the middle push rod 13, and the return spring 12 is sleeved on the middle push rod 13 and used for returning the middle push rod 13;
the electromagnet 16 is arranged on the outer side wall of the cylinder head 1 and positioned at the tail end of the air inlet cam shaft 25, an electromagnet push rod 24 is arranged between the electromagnet 16 and the air inlet cam shaft 25, the electromagnet push rod 24 is arranged in the side wall of the cylinder head 1, one end of the electromagnet push rod 24 is driven by the electromagnet 16, and the other end of the electromagnet push rod is abutted against the tail end of the middle push rod 13.
In the above structure, the high speed intake cam 6 is mounted on the intake camshaft 25 with clearance, when the speed is lower than the designed speed, the friction spring 5 rotates with the low speed intake cam 7 due to the pressing action, but when the high speed intake cam 6 contacts with the intake rocker 23, the high speed intake cam 6 is mounted on the intake camshaft 25 with clearance only, the single shaft rotation degree of freedom is not limited, so the molded line of the high speed intake cam 6 clings to the intake rocker 23, but does not output action effect to the intake rocker 23, at this time, the engine intakes according to the molded line structure of the low speed intake cam 7; when the rotating speed is higher than the designed rotating speed, the high-speed air inlet cam 6 and the low-speed air inlet cam 7 are inserted with the synchronous bolt 9, the double shafts limit the rotational freedom degree of the high-speed air inlet cam 6, and the molded line of the high-speed air inlet cam 6 contains (is larger than) the molded line of the low-speed air inlet cam 7, and at the moment, the air inlet rule of the engine is carried out according to the high-speed air inlet cam 6;
in order to facilitate understanding of the above principle, a specific operating condition analysis is now performed:
firstly, the high-speed intake cam 6 is contacted with the intake rocker 23 before the synchronous bolt is inserted, but the high-speed intake cam 6 only rotates and cannot overcome the valve spring 20 to output the cam profile outwards;
after the high-speed air inlet cam 6 and the low-speed air inlet cam 7 are fixedly connected through the synchronous bolt 9, the molded line of the high-speed air inlet cam 6 is larger than (contains) the molded line of the low-speed air inlet cam (namely, an outer contour), and at the moment, the air inlet cam 6 outputs the molded line of the cam;
thirdly, after the synchronous bolt 9 is reset, the high-speed intake cam 6 can rotate at any position until the synchronous bolt contacts with the intake rocker arm 23 again (returns to the first working condition), at the moment, the high-speed intake cam 6 only contacts with and rotates, but the molded line of the high-speed intake cam 6 is not output, so that the resetting of the high-speed intake cam 6 does not influence the next synchronization, because under the action of the low-speed intake cam 7, the synchronous bolt 9 can be inserted into the blind hole 601 of the high-speed intake cam 6 within 20ms as long as the low-speed intake cam 7 rotates for 1 circle, and the time of the synchronous bolt can be completed within 0.02 s; the problem of friction life between the high-speed cam and the low-speed cam can be solved by the following technical means: the surface high-frequency quenching is detected by tests, no abnormality exists for 200 hours continuously under the high-speed working condition of 9000 revolutions per minute, and the engine is lubricated by organic oil and can reduce friction.
Specifically, the synchronous bolt 9 is arranged on the low-speed air inlet cam 7, when the rotating speed is lower than the designed rotating speed, the synchronous bolt 9 is only arranged in the low-speed air inlet cam 7 and rotates along with the low-speed air inlet cam 7, and air inlet of the engine is organized according to the low-speed air inlet cam 7; when the rotating speed is higher than the designed rotating speed, the ECU controls the electromagnet 16 to realize three-stage transmission, so that the synchronous bolt 9 is simultaneously inserted into the high-speed air inlet cam 6 and the low-speed air inlet cam 7, and the engine enters air according to the molded line organization of the high-speed air inlet cam 6; wherein tertiary transmission includes: in primary transmission, the electromagnet 16 pushes the electromagnet push rod 24; in secondary transmission, the electromagnet push rod 24 pushes the middle push rod 13; and in three-stage transmission, the middle push rod 13 pushes the synchronous bolt 9, so that the synchronous bolt 9 is simultaneously inserted between the high-speed air inlet cam 6 and the low-speed air inlet cam 7 to be fixedly connected.
The whole intake camshaft 25 is of a coaxial three-step shaft structure, and comprises a first step shaft 251 at the head end, a second step shaft 252 at the middle part, and a third step shaft 253 at the tail part, wherein the diameter of the second step shaft 252 is larger than that of the first step shaft 251, the low-speed intake cam 7 is fixedly integrated between the second step shaft 252 and the third step shaft 253, the high-speed intake cam 6 is arranged on the second step shaft 252 and is in clearance fit with the second step shaft 252, the key groove C255 is arranged at the tail end of the third step shaft 253, a key groove A254 axially penetrating through the third step shaft 253 is further arranged on the outer circumferential surface of the third step shaft 253, the head end of the key groove A254 is used for accommodating the tail end of the synchronous bolt 9, the key groove A254 is communicated with the key groove C255 and is positioned at the radial outer side of the key groove C255, the head end of the key groove A254 corresponds to the through hole 701 of the low-speed intake cam 7, the through hole 701 is positioned at the radial outer side of the key groove A254, it is ensured that the intermediate push rod 13 can push the synchronization bolt 9 into the blind hole 601.
The air inlet camshaft 25 is further sleeved with a positioning sleeve A18, the positioning sleeve A18 is located inside the camshaft front gland 2, the positioning sleeve A18 is in interference fit with the air inlet camshaft 25, and the axial degree of freedom of the air inlet camshaft 25 is limited through the camshaft front gland 2; the friction spring 5 is sleeved on the positioning sleeve A18, gaskets A4 are respectively arranged at two ends of the friction spring 5, one gasket A4 is sleeved in the middle of the positioning sleeve A18 and is abutted against the outer wall of the front gland 2 of the camshaft, and the other gasket A4 is sleeved on the air inlet camshaft 25 and is located between the friction spring 5 and the high-speed air inlet cam 6.
The end face of the tail end of the intake camshaft 25 is provided with a gasket B11, the middle push rod 13 is arranged in the middle of the gasket B11 in a penetrating mode, and the return spring 12 is located between the gasket B11 and the tail end of the middle push rod 13.
The head ends of the exhaust camshaft 3 and the intake camshaft 25 are respectively connected with a timing driven sprocket 17, and the timing driven sprocket 17 is driven by an engine and respectively drives the intake camshaft 25 and the exhaust camshaft 3 to rotate.
A positioning sleeve B14 is arranged in the side wall of the cylinder head 1, and the electromagnet push rod 24 is arranged in the side wall of the cylinder head 1 through a positioning sleeve B14; an oil seal 15 is arranged between the positioning sleeve B14 and the electromagnet 16, and the oil seal 15 is sleeved on the electromagnet push rod 24 and used for sealing the electromagnet push rod 24 and preventing engine oil in the engine from flowing out from the electromagnet push rod 24.
The axis of the electromagnet push rod 24 is coaxial with the end surface of the tail end of the air inlet cam shaft 25; the middle push rod 13 is a cylindrical straight rod with the radius R, the middle part and the head end of the middle push rod 13 are both positioned in the rear gland 10 of the camshaft, the radius of the tail end face of the air inlet camshaft 25 is set to be R, the distance from the axis of the middle push rod 13 to the axis of the tail end face of the air inlet camshaft 25 is set to be D, and R + R is greater than D and is greater than R-R; and a circular boss is arranged on the outer circular surface of the tail end of the middle push rod 13 and is abutted to the electromagnet push rod 24.
Example 1
The structure of embodiment 1 is still as shown in fig. 1 to 7, the connection relationship is not described again, and the structure thereof is now described in detail, and a variable valve actuating mechanism for a motorcycle engine with a dual overhead camshaft mainly includes:
the cylinder head 1 is used for fixing and installing a front camshaft gland 2, an exhaust camshaft 3, an intake camshaft 25, a rear camshaft gland 10, a positioning sleeve B14, an oil seal 15 and an electromagnet 16;
the camshaft front gland 2 is used for fixing the exhaust camshaft 3 and the low-speed intake camshaft;
the exhaust camshaft 3 is used for driving an exhaust rocker arm 19, a valve spring 20 and an exhaust valve 21 to regularly organize exhaust according to the molded line of an upper exhaust cam;
two gaskets A4 are arranged, one gasket is arranged between the front gland 2 of the camshaft and the friction spring 5, and the other gasket is arranged between the friction spring 5 and the high-speed intake cam 6 to play a role in friction reduction;
the friction spring 5 is arranged on the positioning sleeve A, presses the high-speed air inlet cam 6 on the end surface of the low-speed air inlet cam 7 through elasticity, and enables the high-speed air inlet cam 6 to rotate along with the low-speed air inlet cam 7;
a high-speed intake cam 6 which is mounted on the intake camshaft 25 with a gap therebetween;
the low-speed intake cam 7 is fixed on the intake camshaft 25 and is used for driving the intake rocker arm 23 to operate according to the molded line of the low-speed intake cam 7;
the synchronous spring 8 is arranged between the synchronous bolt 9 and the low-speed air inlet cam 7 and is used for controlling the resetting of the synchronous bolt 9;
the synchronous bolt 9 is arranged on the low-speed air inlet cam 7;
a camshaft rear gland 10 for fixing the low-speed intake camshaft 25 and the exhaust camshaft 3;
the gasket B11 is arranged between the camshaft rear gland 10 and the return spring 12 and plays a role in supporting and reducing friction;
the return spring 12 is arranged on the middle push rod 13 and plays a role in returning the middle push rod 13;
the middle push rod 13 is arranged on the low-speed air inlet camshaft 25, is contacted with the synchronous bolt 9 at the end surface of the shaft and is used for controlling the insertion of the synchronous bolt 9;
the positioning sleeve B14 is arranged on the side wall of the cylinder head 1 and is used for supporting the electromagnet push rod 24;
the oil seal 15 is arranged on the side wall of the cylinder head 1 and used for sealing the electromagnet push rod 24 and preventing engine oil in the engine from flowing out of the electromagnet push rod 24;
the electromagnet 16 is arranged on the outer side wall of the cylinder head 1, is an initial execution unit of the variable valve actuating mechanism, indirectly pushes the synchronous bolt 9 and is used for controlling the synchronization of the high-speed air inlet cam 6 and the low-speed air inlet cam 7;
the timing driven sprocket 17 is arranged on the air inlet camshaft 25 and the exhaust camshaft 3 and is driven by an engine to drive the air inlet camshaft 25 and the exhaust camshaft 3 to rotate;
the positioning sleeve A18 is arranged on the air inlet camshaft 25 in an interference manner, the positioning surface of the positioning sleeve A18 is arranged in the front gland 2 of the camshaft, and the axial degree of freedom of the air inlet camshaft 25 is limited by the front gland 2 of the camshaft;
an exhaust rocker arm 19 which is installed in the cylinder head 1 through an exhaust rocker shaft and is directly driven by an exhaust cam on the exhaust camshaft 3, and the exhaust rocker arm 19 drives a valve spring 20 on an exhaust valve 21 to enable the exhaust valve 21 to operate;
n valve springs 20 are arranged, N/2 are arranged on the exhaust valve 21, and N/2 are arranged on the intake valve 22 and are used for controlling the reset of the exhaust valve 21 and the intake valve 22;
an exhaust valve 21 mounted on the cylinder head 1 for controlling engine exhaust;
an intake valve 22 mounted on the cylinder head 1 for controlling engine intake;
the intake rocker arm 23, as shown in fig. 6, is provided with a shaft hole 231, the shaft hole 231 is provided with an intake rocker shaft and is mounted inside the cylinder head 1 through the intake rocker shaft, the intake rocker arm 23 is provided with a driving wheel 232 parallel to the shaft hole 231, the driving wheel 232 is driven by the low-speed intake cam 7 or the high-speed intake cam 6, and then drives the valve spring 20 on the intake valve 22 to make the intake valve 22 run;
the electromagnet push rod 24 is arranged in the positioning sleeve 14 and is directly driven by the electromagnet 16;
and the air inlet camshaft 25 is arranged on the cylinder head 1, is limited in displacement by the camshaft front gland 2 and the camshaft rear gland 10 and can only rotate.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
The present invention is not described in detail in the prior art.
Claims (7)
1. A variable valve train for a motorcycle engine having a dual overhead camshaft, comprising: cylinder head (1), exhaust camshaft (3), exhaust rocking arm (19), intake camshaft (25), low-speed intake cam (7), high-speed intake cam (6), intake rocking arm (23) and electro-magnet (16), characterized by:
the exhaust camshaft (3) and the intake camshaft (25) are arranged in parallel inside the cylinder head (1), the head ends of the exhaust camshaft (3) and the intake camshaft (25) are fixed on one side inside the cylinder head (1) through a camshaft front gland (2), the tail ends of the exhaust camshaft (3) and the intake camshaft (25) are fixed on the other side inside the cylinder head (1) through a camshaft rear gland (10), an exhaust cam is arranged on the exhaust camshaft (3) and used for driving an exhaust rocker arm (19), and a low-speed intake cam (7) and a high-speed intake cam (6) are sleeved on the intake camshaft (25) and used for driving an intake rocker arm (23); the exhaust rocker arm (19) is arranged on one side, provided with the exhaust camshaft (3), in the cylinder head (1), and the intake rocker arm (23) is arranged on one side, provided with the intake camshaft (25), in the cylinder head (1);
the high-speed air inlet cam (6) is arranged between the low-speed air inlet cam (7) and the front cam shaft gland (2), a friction spring (5) is arranged between the high-speed air inlet cam (6) and the front cam shaft gland (2), and the friction spring (5) is sleeved on the air inlet cam shaft (25) and used for pressing the high-speed air inlet cam (6) on the end face of the low-speed air inlet cam (7); the end surface of the high-speed air inlet cam (6) adjacent to the low-speed air inlet cam (7) is provided with a blind hole (601);
an axial through hole (701) is formed in the low-speed air inlet cam (7), a synchronous bolt (9) is arranged in the through hole (701), the head end of the synchronous bolt (9) is matched with the blind hole (601) of the high-speed air inlet cam (6), a synchronous spring (8) is arranged between the tail end of the synchronous bolt (9) and the low-speed air inlet cam (7), and the synchronous spring (8) is sleeved on the synchronous bolt (9) and used for resetting the synchronous bolt (9);
the tail end of the air inlet cam shaft (25) is provided with an axial key groove C (255), a movable middle push rod (13) is arranged in the key groove C (255), the head end of the middle push rod (13) is abutted against the synchronous bolt (9), and the tail end of the middle push rod (13) penetrates through the tail end face of the air inlet cam shaft (25) and is positioned outside the tail end of the air inlet cam shaft (25); a return spring (12) is arranged between the air inlet camshaft (25) and the tail end of the middle push rod (13), and the return spring (12) is sleeved on the middle push rod (13) and used for returning the middle push rod (13);
the electromagnet (16) is arranged on the outer side wall of the cylinder head (1) and positioned at the tail end of the air inlet cam shaft (25), an electromagnet push rod (24) is arranged between the electromagnet (16) and the air inlet cam shaft (25), the electromagnet push rod (24) is arranged in the side wall of the cylinder head (1), one end of the electromagnet push rod is driven by the electromagnet (16), and the other end of the electromagnet push rod is abutted to the tail end of the middle push rod (13);
the whole three-stage step shaft structure that sets up of air inlet camshaft (25) be coaxial, it includes first step axle (251) of head end, second step axle (252) at middle part, third step axle (253) of afterbody, the diameter of second step axle (252) is greater than first step axle (251), low-speed air inlet cam (7) solid setting as an organic whole between second step axle (252) and third step axle (253), high-speed air inlet cam (6) set up on second step axle (252) and with second step axle (252) clearance fit.
2. The variable valve gear for a motorcycle engine with a dual overhead camshaft as claimed in claim 1, wherein: keyway C (255) set up at third step axle (253) tail end, still be equipped with keyway A (254) that the axial runs through third step axle (253) on the excircle face of third step axle (253), keyway A (254) and keyway C (255) intercommunication and lie in the radial outside of keyway C (255), the head end of keyway A (254) and low-speed intake cam (7) through-hole (701) are corresponding, through-hole (701) lie in the radial outside of keyway A (254).
3. The variable valve gear for a motorcycle engine with a dual overhead camshaft as claimed in claim 1, wherein: the air inlet camshaft (25) is further sleeved with a positioning sleeve A (18), the positioning sleeve A (18) is located inside the camshaft front gland (2), the positioning sleeve A (18) is in interference fit with the air inlet camshaft (25), and the axial degree of freedom of the air inlet camshaft (25) is limited through the camshaft front gland (2); the friction spring (5) is sleeved on the positioning sleeve A (18), the two ends of the friction spring (5) are respectively provided with a gasket A (4), one gasket A (4) is sleeved in the middle of the positioning sleeve A (18) and is abutted to the outer wall of the camshaft front gland (2), and the other gasket A (4) is sleeved on the air inlet camshaft (25) and is located between the friction spring (5) and the high-speed air inlet cam (6).
4. The variable valve gear for a motorcycle engine with a dual overhead camshaft as claimed in claim 1, wherein: the end face of the tail end of the air inlet camshaft (25) is provided with a gasket B (11), the middle push rod (13) penetrates through the middle of the gasket B (11), and the reset spring (12) is located between the gasket B (11) and the tail end of the middle push rod (13).
5. The variable valve gear for a motorcycle engine with a dual overhead camshaft as claimed in claim 1, wherein: the head ends of the exhaust camshaft (3) and the intake camshaft (25) are respectively connected with a timing driven sprocket (17), and the timing driven sprocket (17) is driven by an engine and respectively drives the intake camshaft (25) and the exhaust camshaft (3) to rotate.
6. The variable valve gear for a motorcycle engine with a dual overhead camshaft as claimed in claim 1, wherein: a positioning sleeve B (14) is arranged in the side wall of the cylinder head (1), and the electromagnet push rod (24) is arranged in the side wall of the cylinder head (1) through the positioning sleeve B (14); an oil seal (15) is arranged between the positioning sleeve B (14) and the electromagnet (16), and the oil seal (15) is sleeved on the electromagnet push rod (24) and used for sealing the electromagnet push rod (24) and preventing engine oil in the engine from flowing out of the electromagnet push rod (24).
7. The variable valve gear for a motorcycle engine with a dual overhead camshaft as claimed in claim 1, wherein: the axis of the electromagnet push rod (24) is coaxial with the end surface of the tail end of the air inlet cam shaft (25); the middle push rod (13) is a cylindrical straight rod with the radius R, the middle part and the head end of the middle push rod (13) are both positioned in the rear gland (10) of the camshaft, the radius of the tail end face of the intake camshaft (25) is set to be R, the axial distance from the axis of the middle push rod (13) to the tail end face of the intake camshaft (25) is set to be D, and R + R is greater than D and is greater than R-R; and a circular boss is arranged on the outer circular surface of the tail end of the middle push rod (13), and the circular boss is abutted to the electromagnet push rod (24).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110912336.5A CN113550806B (en) | 2021-08-10 | 2021-08-10 | Variable valve actuating mechanism for motorcycle engine with double overhead camshafts |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110912336.5A CN113550806B (en) | 2021-08-10 | 2021-08-10 | Variable valve actuating mechanism for motorcycle engine with double overhead camshafts |
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| CN113550806A CN113550806A (en) | 2021-10-26 |
| CN113550806B true CN113550806B (en) | 2022-08-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202110912336.5A Active CN113550806B (en) | 2021-08-10 | 2021-08-10 | Variable valve actuating mechanism for motorcycle engine with double overhead camshafts |
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| CN114483357B (en) * | 2021-12-24 | 2024-02-27 | 力帆科技(集团)股份有限公司 | Motorcycle engine |
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| GB2196694A (en) * | 1986-10-23 | 1988-05-05 | Honda Motor Co Ltd | I.C. engine valve gear |
| US5036807A (en) * | 1989-06-30 | 1991-08-06 | Isuzu Motors Limited | Variable valve timing lift device |
| US5704316A (en) * | 1993-09-20 | 1998-01-06 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Valve drive system of an internal combustion engine |
| CN2913619Y (en) * | 2006-04-14 | 2007-06-20 | 江门市硕普科技开发有限公司 | Engine self-adaptive spiracle phase apparatus |
| CN102606244A (en) * | 2012-04-01 | 2012-07-25 | 江门市硕普科技开发有限公司 | Mechanical type continuously variable valve mechanism of engine |
| WO2017146002A1 (en) * | 2016-02-26 | 2017-08-31 | 武蔵精密工業株式会社 | Variable cam phase mechanism in valve operating device for internal combustion engine |
| JP2017218924A (en) * | 2016-06-03 | 2017-12-14 | 武蔵精密工業株式会社 | Cam phase variable valve gear for internal combustion engine |
| TWM607021U (en) * | 2020-05-21 | 2021-02-01 | 三陽工業股份有限公司 | Apparatus for variable valve timing control |
-
2021
- 2021-08-10 CN CN202110912336.5A patent/CN113550806B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2196694A (en) * | 1986-10-23 | 1988-05-05 | Honda Motor Co Ltd | I.C. engine valve gear |
| US5036807A (en) * | 1989-06-30 | 1991-08-06 | Isuzu Motors Limited | Variable valve timing lift device |
| US5704316A (en) * | 1993-09-20 | 1998-01-06 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Valve drive system of an internal combustion engine |
| CN2913619Y (en) * | 2006-04-14 | 2007-06-20 | 江门市硕普科技开发有限公司 | Engine self-adaptive spiracle phase apparatus |
| CN102606244A (en) * | 2012-04-01 | 2012-07-25 | 江门市硕普科技开发有限公司 | Mechanical type continuously variable valve mechanism of engine |
| WO2017146002A1 (en) * | 2016-02-26 | 2017-08-31 | 武蔵精密工業株式会社 | Variable cam phase mechanism in valve operating device for internal combustion engine |
| JP2017218924A (en) * | 2016-06-03 | 2017-12-14 | 武蔵精密工業株式会社 | Cam phase variable valve gear for internal combustion engine |
| TWM607021U (en) * | 2020-05-21 | 2021-02-01 | 三陽工業股份有限公司 | Apparatus for variable valve timing control |
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| CN113550806A (en) | 2021-10-26 |
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