(a) Technical Field of the Invention
[0001] The present invention generally relates to a. driving member of valve of engine,
and more particularly to a structure of valve driving member of engine that simplifies
engineering of variable lift of an engine valve.
(b) Description of the Prior Art
[0002] FIG 1 of the attached drawings shows a conventional structure of valve variable-lift:
mechanism for an engine, 1, wherein first and second driving members 21, 22 are arranged
above an engine valve 2. The second driving member 22 is a multiple-link assembly.
The first and second driving members 21., 22 may individually drive the engine valve
2 to realize variation of lift stroke of the engine valve 2. In other words, when
the engine valve 2 is driven by the first driving member 21, the engine valve 2 is
of a small lift opening condition, while when the engine valve 2 is driven by the
second driving member 22, the engine valve 2 is of a large lift opening condition.
As such, switching of intake and exhaust valves can be realized for different lifts
of engine valve 2 according to rotational, speeds of the engine 1.
[0003] The conventional structure of valve variable-lift mechanism for the engine 1 described
above uses the first and second driving members 21, 22 arranged above the engine valve
2 to individually drive the engine valve 2. Although this is effective to realize
switching of intake and exhaust valves for different lifts of engine valve 2 according
to the rotational speeds of the engine i, yet the second driving member 22 is of a
multiple-link assembly, which is complicated in structure and requires quite an amount
of space for operation. Thus, the cylinder head 1 a of the engine 1 must be enlarged
in order to provide a sufficient amount of space for the operation of the second driving
member 22. Enlarging the cylinder head 1 a of the engine 1 will ce inly increase the
cost of the engine 1 and also increase complication of engineering for the engine
1. For a motorcycle or scooter, the amount of space provided for accommodating an
engine 1 is very limited. Thus, it is desired to provide a stmcture-simplined valve
variable-lift mechanism for engines and this is a major challenge of the motorcycle/scooter
industry.
SUMMARY OF THE INVENTION
[0004] The primary objective of the present invention is to provide a structure of driving
member of valve of engine, wherein the engine comprises a crankcase, a cylinder block
mounted on the crankcase, and a cylinder head mounted on the cylinder block. The cylinder
head comprises an intake port and an intake valve and an exhaust port and an exhaust
valve, and an oil control valve. A cams seat is arranged between the intake valve
and the exhaust valve. The camshaft seat comprises a camshaft that is driven by a
timing chain. The camshaft comprises a first intake cam, a second intake cam, and
an exhaust cam mounted thereto. Through the first intake cam, the second intake cam,
and the exhaust cam, the camshaft, when put in rotation, drives an intake valve driving
member or an exhaust valve driving member, and further, through the intake valve driving
member or the exhaust valve driving member, the intake valve or the exhaust valve
is caused to take a lift for intake or exhaust operation. The intake valve driving
member comprises a first driving member and a second driving member. The first driving
member forms a positioning hole, a bore, and a push roller and the second driving
member forms a positioning hole, a bore, a push roller, and a pressing section. The
push roller of the first driving member is in engagement with the first cam and the
push roller of the second driving member is in engagement with the second intake cam.
Further, the pressing section of the second driving member is in engagement with the
intake valve. The bore of the first driving member and the bore of the second driving
member are in communication with each other to form a hydraulic cylinder. The hydraulic
cylinder has two ends respectively closed by closure caps. `fho hydraulic cylinder
receives therein a spring and first and second pistons. As such, the first driving
member and the second driving member can be selectively driven to operate independent
of each other or in combination with each other to vary the lift of an engine intake
valve thereby sin1plifying the engineering of variable lift for engine intake vale.
[0005] Another objective of the present invention is to provide a structure of driving member
of valve of engine, wherein a position-constraining mechanism is arranged above the
cylinder head and the position-constraining mechanism comprises a position-constraining
rod, a spring, and a pressure relief hole, whereby with the position-constraining
mechanism being in pushing engagement with the first driving member and the second
driving member the positioning bar, it is ensured that the bores of the first and
second driving members can be set at predetermined locations.
[0006] A further objective of the present invention is to provide a structure of driving
member of valve of engine, wherein the first driving member and the second driving
member comprise positioning bars that are located between the positioning holes and
the pressing section and the bores of the first and second driving members are located
between, the push rollers and the positioning holes and located above a center-connection
line connecting between centers of the push rollers and the positioning holes whereby
the overall height of the cylinder head is effectively reduced.
[0007] The foregoing objectives and summary provide only a brief introduction to the present
invention. To fully appreciate these and other objects of the present invention as
well as the invention itself, all of which will become apparent to those skilled in
the art, the following detailed description of the invention and the claims should
be read in conjunction with the accompanying drawings. Throughout the specification
and drawings identical reference numerals refer to identical or similar parts.
[0008] Many other advantages and features of the present invention will become manifest
to those versed in the art upon making reference to the detailed description and the
accompanying sheets of drawings in which a preferred structural embodiment incorporating
the principles of the present invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
FIG 1 is schematic view showing a conventional cylinder head.
FIG 2 is a perspective view illustrating an engine cylinder head according to the
present invention.
FIG 3 is a cross-sectional view of a portion of the cylinder head according to the
present invention.
FIG 4 is a perspective view illustrating a camshaft according to the present invention.
FIG 5 is a top view of the cylinder head according to the present invention.
FIG 6 is a perspective view illustrating an exhaust valve driving member according
to the present invention.
FIG 7 is an exploded view illustrating an intake valve driving member according to
the present invention.
FIGS. 8 and 9 are schematic views illustrating the operation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] The following descriptions are exemplary embodiments only, and are not intended to
limit the scope, applicability or configuration of the invention in any way. Rather,
the following description provides a convenient illustration for implementing exemplary
embodiments of the invention. Various changes to the described embodiments may be
made in the function and arrangement of the elements described without departing from
the scope of the invention as set forth in the appended claims.
[0011] Referring to FIG 2, the present invention provides an engine 3, which comprises a
crankcase 31, a cylinder block 32 that is mounted on the crankcase 31, and a cylinder
head 33 that is mounted on the cylinder block 32.
[0012] The crankcase 31 comprises a crankshaft (not shown) arranged therein. The crankcase
31 comprises an oil pump 31 arranged therein. The oil pump 311 pumps oil to a primary
oil supply passage 312. The primary oil supply passage 312 extends from the crankcase
31 through the cylinder block 32 to communicate an oil control valve 4 that is mounted
to the cylinder head 33.
[0013] The cylinder block 32 is mounted on the crankcase 31 and receives a timing chain
5 to extend therethrough. The cylinder block 32 comprises a timing chain tensioner
5 that is arranged at a side corresponding to an intake port 331 of the cylinder head
33.
[0014] The cylinder head 33 comprises the intake port 331 that is arranged at an intake
side and an intake valve 332 and an exhaust port 333 that is arranged at an exhaust
side and an exhaust valve 334. Referring to FIGS. 2,3,4, and 5, the cylinder head
33 comprises a camshaft seat 335 that is integrally formed between the intake valve
332 and the exhaust valve 334. The camshaft seat 335 comprises a camshaft 336 that
is driven by the timing chain 5. The camshaft 336 comprises a first intake cam (high
lift cam) 3361, a second intake cam (low lift cam) 3362, and an exhaust cam 3363 mounted
thereto. Through the first intake cam 3361, the second, intake cam 3362, and the exhaust
cam 3363, the camshaft 336, when in rotation, may drive an intake valve driving member
6 and an exhaust valve driving member 7 of the intake valve 332 and the exhaust valve
334. Referring to FIGS. 3, 5, and 6, the exhaust valve driving member 7 has an end
forming a pressing section 71, which is in engagement with the exhaust valve 334 and
has an end forming a gap adjusting member 711, and an opposite end forming a push
roller 72, which is in engagement with the exhaust cam 3363. A bearing sleeve 73 extends
sideways from a side of the exhaust valve driving member 7 for receiving the extension
of a shaft rod 74 therethrough. Through the shaft rod 74, the exhaust valve driving
member 7 is securely positioned, on the camshaft seat 335, whereby the exhaust cam
3363 of the camshaft 336 may drive the push roller 72 to have the pressing section
7 pressing the exhaust valve 334 for opening the exhaust valve to discharge exhaust
gas. A gap between the pressing section 71 and the exhaust valve 334 can be adjusted
through the gap adjusting member 711 in order to ensure the exhaust valve 334 has
a desired lift stroke. Further, referring to FIGS. 3, 5, and 7, the intake valve driving
member 6 comprises a first driving member 61 and a second driving member 62. The first
driving member 61 forms in a front portion thereof a positioning hole 611, a positioning
bar 612 being arranged to project from a front lower side of the positioning hole
611, and also forms a through bore 613 at a location behind the positioning hole 61
I , a push roller 614 being arranged behind the bore 613 . Corresponding to the first
driving member 61, the second driving member 62 forms, in sequence, a positioning
hole 621, a positioning bar 622, a through bore 623, and a push roller 624. Further,
the second driving member 62 comprises a pressing section 625 extending from a front
side of the positioning hole 621 and the pressing section 625 has a front end forming
a gap adjusting member 6251. The push roller 614 of the first driving member 61 is
set in engagement with the first intake cam 336 of the camshaft 336, while the push
roller 624 of the second driving member 62 is in with the second intake cam 3362 of
the camshaft 336. Further, the pressing section 625 of the second driving member 62
is in engagement with the intake valve 332. A gap between the pressing section 625
and the intake valve 332 can be adjusted through the gap adjusting member 6251 in
order to ensure that the intake valve 332 has a desired lift stroke. Further, with
a shaft rod 63 received through the positioning holes 611 621, the first driving member
61 and the second driving member 62 are securely positioned on the camshaft seat 335,
whereby the first driving member 61 and the second driving member 62 are reciprocally
rotatable about a center defined by the shaft rod 63. Further, as shown in FIG 3,
the positioning bars 612, 622 of the first driving member 61 and the second driving
member 62 are respectively arranged at locations between the positioning holes 611,
621 and the pressing section 625. The bores 613, 623 of the first driving member 61
and the second driving member 62 are located between the push rollers 614, 624 and
the positioning holes 611, 621 and are located above a center-connection line A connecting
between centers of the push roller 614, 624 and the positioning holes 611, 621 so
as to effectively reduce the overall height of the cylinder head 33. Referring to
FIGS. 5, 7, 8, and 9, the bore 613 of the first driving member 61 and the bore 623
of the second driving member 62 are arranged to connect to and communicate each other
to collectively form a hydraulic cylinder 64. The hydraulic cylinder 64 has opposite
ends that are respectively closed and sealed by closure caps 641a, 641b. Each of the
closure caps 641a,641b forms a projecting peg 6411a, 6411b extending inward of the
hydraulic cylinder 64. The hydraulic cylinder 64 receives therein a spring 642 and
a first piston 643 and a second piston 644, which are hydraulically movable by oil
pressure. The hydraulic cylinder 64 is connected through driving oil passages 65,66
to the oil control valve 4 in order to receive hydraulic power therefrom. Further,
the first piston 643 has two ends respectively forming a first recess 6431 and a second
recess 6432 for the purposes of reducing weight of the first piston 643 and thus enhancing
movability of the first piston 643 within the hydraulic cylinder 64. The first recess
6431 is shaped to receive the projecting peg 6411a of the closure cap 641a therein
and the projecting peg 6411b of the closure cap 641b is engageable with an end of
the second piston 644, whereby the first piston 643 and the second piston 644 are
spaced from the ends of the hydraulic cylinder 64 by distances to allow oil flowing
through the driving oil passages 65, 66 into the hydraulic cylinder 64 may reliably
move the first piston 643 and the second piston 644. Further, with the projecting
pegs 6411a, 6411b of the closure caps 641a, 641b, the first piston 643 and the second
piston 644 are positionable at predetermined locations during their operations so
as to ensure the movability of the first piston 643 and the second piston 644 within
the hydraulic cylinder 64. Further, the cylinder head 33 is provided, at a location
below the positioning bars 612,622, with a position-constraining mechanism 337. The
position-constraining mechanism 337 comprises a position-constraining rod 3371, a
spring 3372, and a pressure relief hole 3373. The position-constraining mechanism
337 is provided for supporting pushing engagement of the positioning bars 612, 622
in order to ensure that the bore 613 of the first driving member 6 and the bore 623
of the second driving member 62 can be set at predetermined locations. Further, when
the position-constraining mechanism 337 is acted upon by undue pushing forces applied
by the positioning bars 612, 622, the pressure relief hole 3373 is timely opened to
release pressure in order to ensure the movability of the first piston 643 and the
second piston 644 within the hydraulic cylinder 64.
[0015] To practice the present invention, as shown in FIGS. 2, 3, 8, and 9, the oil pump
31 arranged in the crankcase 31 pumps oil to the primary oil supply passage 312, which
extends from the crankcase 3 through the cylinder block 32 to communicate the oil
control valve 4 that is mounted to the cylinder head 3, wherein the oil control valve
4 supplies the oil into the driving oil passages 65,66 of the cylinder head 33 to
feed into the hydraulic cylinder 64. Further, as shown in FIGS. 8 and 9, through detection
of traveling condition of a vehicle by an ECU (not shown) of the engine, 3, if it
is determined that the engine valve requires only low lift opening, the ECU of the
engine 3 instructs the oil control valve 4 to feed the oil through the driving oil
passage 65 into the hydraulic cylinder 64, as shown in FIG. 8, whereby through the
oil pressure and a spring force of the spring 642, the first piston 643 and the second
piston 644 are moved in a direction toward the first driving member 61 . The oil,
after flowing through the driving oil passage 65 into the bore 621 of the second driving
member 62, is guided by the projecting peg 6411 of the closure cap 641a and the first
piston 643 into the recess 643 of the first piston 643, and at the same time, the
oil contained in the first driving member 61 is forced to discharge through the driving
oil passage 66, whereby the second piston 644 is moved to locate within the first
driving member 61 and is positioned at a predetermined location by the projecting
peg 6411b of the closure cap 6411b at the side corresponding to the first driving
member 61 and the first piston 643 is located in the second driving member 62. Under
this condition, the first driving member 6 and the second driving member 62 are allowed
to rotate independent of each other. Since the pressing section 625 at the front end
of the second driving member 62 is in engagement with the intake valve 332 and the
push roller 624 at the rear end of the second driving member 62 is in engagement with
the second intake cam (low lift cam) 3362 of the camshaft 336, the intake valve 332
of the engine 3 is set in a low lift opening condition. Further, when the engine 3
is switched, due to change of vehicle traveling condition, to a high lift opening
condition for the intake valve, the ECU of the engine 3 instructs the oil control
valve 4 to feed oil through the driving oil passage 66 into the hydraulic cylinder
64, as shown in FIG 9, whereby the oil flows through the driving oil passage 66 into
the bore 613 of the first driving member 6 and at the same time, the oil contained
in the bore 623 of the second driving member 62 is discharged. Through the oil pressure,
the first piston 643 and the second piston 644 are moved in a direction toward the
second driving member 62 to have the first piston 643 located in the second driving
member 62 and through the constrain imposed by the projecting peg 641 a of the closure
cap 641a of the second driving member 62, the first piston 643 and the second piston
644 are located at predetermined locations where the second piston 644 is set between
the first driving member 61 and the second driving member 62, whereby the first driving
member 6 and the second driving member 62 are coupled to each other. Since the push
roller 614 at the rear end of the first driving member 61 is in engagement with the
first intake cam (high lift cam) 3361 of the camshaft 336 and the pressing section
625 at the front end of the second driving member 62 is in engagement with the intake
valve 332, the second driving member 62 is moved by the first driving member 61 to
set the intake valve 332 to a desired high lift opening condition according to the
lift of the first intake cam (high lift cam) 3361. As such, variable valve lift of
the engine 3 can be realized.
[0016] Efficacies of the present invention are that the camshaft 336 is provided with the
first intake cam 3361, the second intake cam 3362, and the exhaust 3363, and the intake
valve driving member 6 comprises the first driving member & and the second driving
member 62, and er, the bore 613 of the first driving member 61 and the bore 623 of
the second driving member 62 are in communication with each other to form the hydraulic
cylinder 64, with the spring 642 and the first piston 643 and the second piston 644
that are movable hydraulically and by the spring 642 being contained within the hydraulic
cylinder 64, the first driving member 61 and the second driving member 62 are selectively
rotatable independent of each other or in combination with each other to vary lift
stroke of the valve 332 of the engine 3, and thus simplifying engineering of variable
lift for the engine valve 332 of the engine 3. Further, with the positioning bars
612, 622 of the first driving ember 6 and the second driving member 62 located between
the positioning holes 611, 621 and the pressing section 625 and with the bores 613,
623 of the first driving member 61 and the second driving member 62 located between
the push rollers 613, 6232 and the positioning holes 611, 621 and located above the
center-connection line At connecting between centers of the push rollers 614, 624
and the positioning holes 611, 621, the overall height of the cylinder head 33 is
effectively reduced.
[0017] It will be understood that each of the elements described above, or two or more together
may also find a useful application in other types of methods differing from the type
described above.
[0018] While certain novel features of this invention have been shown and described and
are pointed out in the annexed claim, it is not intended to be limited to the details
above, since it will be understood that various omissions, modifications, substitutions
and changes in the forms and details of the device illustrated and in its operation
can be made by those skilled in the art without departing in any way from the spirit
of the present invention.
1. A driving member of valve of engine, the engine (3) comprising a crankcase (31), a
cylinder block (32) mounted on the crankcase (31), and a cylinder head (33) mounted
on the cylinder block (32), the cylinder head (33) comprising an intake port (331)
and an intake valve (332) and an exhaust port (333) and an exhaust valve (334), a
camshaft seat (335) being arranged between the intake valve (332) and the exhaust
valve (334), the camshaft seat (335) comprising a camshaft (336) that is driven by
a timing chain (5), the camshaft (336) comprising a first intake cam (3361), a second
intake cam (3362), and an exhaust cam (3363) mounted thereto, whereby through the
first intake cam (3361), the second intake cam (3362), and the exhaust cam (3363),
the camshaft (336), when put in rotation, drives an intake valve driving member (6)
or an exhaust valve driving member (7), and further, through the intake valve driving
member (6) or the exhaust valve driving member (7), the intake valve (332) or the
exhaust valve (334) is caused to operate, characterized in that the intake valve driving member (6) comprises a first driving member (&1} and a second
deriving member (62), the first driving member (61) forming a positioning hole (611),
a bore (613), and a push roller (614), the second driving member (62) forming a positioning
hole (621), a bore (623), a push roller (624), and a pressing section (625), the positioning
holes (611, 612) of the first driving member (61) and the second driving member (62)
receiving extension of a shaft rod (63) therethrough, the push roller (614) of the
first driving member (61) being in engagement with the first intake cam (3361), the
push roller (624) of the second driving member (62) being in engagement with the second
intake cam (3362), the pressing section (625) of the second driving member (62) being
in engagement with the intake valve (332), the bore (613) of the first driving member
(61) and the bore (623) of the second driving member (62) being in communication with
each other to form a hydraulic cylinder (64), whereby the hydraulic cylinder (64)
allows the first driving member (61) and the second driving member (62) to operate
independent of each other in a low lift opening condition of the intake valve (332)
and allows the first driving member (61) and the second driving member (62) to operatively
connect to each other in a high lift opening condition of the intake valve (332).
2. The valve driving member of engine according to claim 1, wherein the cylinder head
(33) comprises an oil control valve (4).
3. The valve driving member of engine according to claim 1, wherein the cylinder head
(33) comprises a position-constraining mechanism (337) in pushing engagement with
the first driving member (61) and the second driving member (62), the position-constraining
mechanism (337) comprising a position-constraining rod (33771), a spring (3372), and
a pressure relief hole (33373).
4. The valve driving member of engine according to claim 3, wherein the first driving
member (61) and the second driving member (62) comprise positioning bars (612, 622),
the positioning bars (612, 622) being in pushing engagement with the position-constraining
rod (3371) of the position-constraining mechanism (337).
5. The valve driving member of engine according to claim 4, wherein the positioning bars
(612, 622) of the first driving member (61) and the second driving member (62) are
located between the positioning holes (611, 621) and the pressing section (625).
6. The valve driving member of engine according to claim 1, wherein the bores (613, 623)
of the first driving member (61) and the second driving member (62) are located between
the push rollers (614, 624) and the positioning holes (611, 62 ) and are located above
a. center-connection line (A) connecting between centers of the push rollers (614,
624) and the positioning holes (611, 621).
7. The valve driving member of engine according to claim 1, 4, or 6, wherein the first
driving member (61) and the second driving member (62) are formed integrally.
8. The valve driving member of engine according to claim 1 or 5, wherein the pressing
section (625) comprises a gap adjusting member (6251).
9. The valve driving member of engine according to claim 1, wherein the hydraulic cylinder
(64) has two ends respectively closed by closure caps (641a, 641b) and receives therein
a spring (642), the first piston (643), and the second piston (644).
10. The valve driving member of engine according to claim 9, wherein the first piston
(643) forms a first recess (6431) and a second recess (6432).
11. The valve driving member of engine according to claim 10, wherein the closure caps
(641a, 641b) form projecting pegs (6411a, 6411b) projecting inward of the hydraulic
cylinder (64).