[0001] The present invention relates to an intake valve device for preventing adhesion of
deposits.
[0002] In poppet valves in engines of automobiles and ships, especially, in intake valves
which has relatively low heat load, if high boiling point organic substances in lubricating
oil leaked from a gap between a valve guide and a valve stem adhere to a valve head
and adjacent area, they will be carbonised at of 200 to 300°C of the intake valve,
gradually aggregated and developed, thereby forming sludges or bulk of deposits. In
the deposits, corrosion ingredients may be contained, which causes corrosion in the
valve head and adjacent area.
[0003] To overcome the disadvantages on the surface of the valve head and adjacent area,
an intake valve is suggested as mentioned Japanese Patent Laid-Open Pub. No.6-235308,
wherein a coating layer which has oxidation catalytic function is formed on the valve
head and adjacent area, thereby preventing high boiling point organic substances from
adhering on the valve head and adjacent area owing to oxidation catalytic reaction
thereof. However, in the intake valve in this publication, an engine runs for a long
time at low load and speed, so that the surface of catalyst is partially covered with
high boiling point organic substances in the lubricating oil owing to oil-down until
the intake valve becomes reaction temperature of the catalyst, and the catalyst is
blocked against air or oxygen. Thus, oxidization catalytic reaction may not be achieved
enough.
[0004] To overcome the disadvantage, it is an object of the present invention to provide
a valve device in which oil-down is directed toward a fuel injection device to prevent
deposits from adhering to a valve head and adjacent area and catalyst surface from
being covered by lubricating oil.
[0005] According to one aspect of the present invention, there is provided an intake valve
device for preventing adhesion of deposits in an internal combustion engine, the device
comprising an intake poppet valve which comprises a valve head and a valve stem; a
valve guide in which the valve is slidably inserted; and fuel injection means which
injects fuel toward the valve head, either of contact surfaces between the valve stem
and the valve guide having an annular groove and an elongate groove which communicates
with the annular groove, a lower end of the elongate groove opening toward an intake
port in the vicinity of the fuel injection means.
[0006] According to another aspect of the present invention there is provided an intake
valve device for preventing adhesion of deposits in an internal combustion engine,
the device comprising an intake poppet valve which comprises a valve head and a valve
stem; a valve guide in which the valve is slidably inserted; and fuel injection means
which injects fuel toward the valve head, either of contact surfaces between the valve
stem and the valve guide having a spiral groove, a lower end of the spiral groove
opening toward an intake port in the vicinity of the fuel injection means.
[0007] According to the present invention, lubricating oil owing to oil-down is guided to
the valve head through the annular and elongate grooves or the spiral groove and washed
down by fuel injected by the fuel injection means, thereby avoiding the lubricating
oil from adhering to the intake valve.
[0008] The features and advantages of the invention will become more apparent from the following
description with respect to embodiments as shown in appended drawings wherein:
Fig. 1 is a sectional view of the first invention;
Fig. 2 is an enlarged horizontal sectional view taken along the line II-II in Fig.
1;
Fig. 3 is an enlarged horizontal sectioned view taken along the line III-III in Fig.
1;
Fig. 4 is an enlarged horizontal sectioned view of of a valve guide of the second
invention;
Fig. 5 is an enlarged vertical sectioned view of an embodiment of the present invention;
and
Fig. 6 is an enlarged view of a coating layer.
[0009] The first invention is illustrated in Fig. 1, in which the numeral 1 denotes an intake
valve which is molded from martensitic heat resisting steels and which comprises a
valve stem 1a and and a valve head 1b at the lower end thereof. The valve stem 1a
of the intake valve 1 is slidably inserted in a cylindrical valve guide 2 which is
pressed in a cylinder head 3, and the intake valve 1 is moved up and down by pushing
the upper surface of a cylindrical tappet 5 at the upper end of the valve stem 1a
by a cam 6. 4 denotes a valve spring.
[0010] At the upper end of the valve guide 2, a lip seal 7 is engaged over the outer circumferential
surface of the valve stem 1a, thereby preventing excessive lubricating oil 8 from
running into a gap between the valve stem 1a of the intake valve 1 and the valve guide
2.
[0011] In the vicinity of the intake valve 1, an injector 9 for injecting gasoline in vapour
is provided in the cylinder head 3, and an injection port 9a is directed to the surface
of the valve head 1b in the intake port 10. On the surface of the valve guide 2 which
contacts the intake valve 1, there is formed an annular groove 2a and an elongate
groove 2b which communicates with the annular groove 2a at the upper end and which
extends to the lower end of the valve guide 2. The lower end of the elongate groove
2b opens toward the intake port 10, which is also shown in Figs. 3 and 4.
[0012] The function of the embodiment as above will be described. The lubricating oil 8
which runs in the gap between the valve stem 1a of the intake valve 1 and the valve
guide 2 is temporarily held in the annular groove 2a. The lubricating oil 8 in the
annular groove 2a runs into the lower end of the valve stem 1a of the intake valve
1 in the intake port 10 and reaches the valve head 1b in the vicinity of the injector
9 via the elongate groove 2a. The gasoline 11 is blown to the lower end of the valve
stem 1a of the intake valve 1 and the head 1b by the injector 9, so that the lubricating
oil 8 which adheres thereon is washed down by the gasoline 11 and sucked into the
cylinder 12. Therefore, the lubricating oil 8 hardly adheres on the surface of the
intake valve 1 in the intake port 10.
[0013] In the above embodiment, the annular groove 2a and the elongate groove 2b are both
formed on the valve guide 2, but may be formed on the intake valve 1.
[0014] Preferably, the annular groove 2a may be formed as low as possible. So far as the
lubricating oil 8 invaded in the gap between the valve guide and the intake valve
1 is held in the annular groove 2a, the lubricating oil does not reach the contact
surface lower than the annular groove 2a. It is for preventing lubrication decrease.
[0015] An embodiment of the second invention will be illustrated in Fig. 4. Difference between
the above and present embodiments is only a groove in the inner circumferential surface
of the valve guide 13, and the other illustration will be omitted. A spiral groove
14 is formed on the whole inner circumferential surface of the valve guide 13, and
an opening 14a at the lower end of the spiral groove 14 communicates with the intake
port 10 in the vicinity of the injector 9 similar to the elongate groove 2b in the
foregoing embodiment.
[0016] The lubricating oil 8 invaded into a gap between the intake valve 1 and the valve
guide 13 runs into the spiral groove 14 and reaches the valve head 1b of the intake
valve 1 in the vicinity of the injector 9 similar to the foregoing embodiment. The
oil 8 which adheres on the valve head 1b is washed down by the gasoline 11 from the
injector 9. This embodiment achieves similar advantage to the foregoing embodiment,
and the spiral groove 14 provides excellent oil-maintenance capability compared with
the elongate groove 2b, and increases lubricating properties of contact surfaces of
the intake valve 1 and the valve guide 13.
[0017] The spiral groove 14 may be formed from a suitable position on the inner circumferential
surface of the valve guide 13 to the lower end of the valve guide 13. The spiral groove
14 may be formed on the intake valve 1.
[0018] Another embodiment of the present invention will be illustrated in Fig. 5, in which
a coating layer having oxidation catalytic function is formed on a portion of the
intake valve 1 in the intake port 10, i.e. on the lower end of the valve stem 1a and
the head 1b on which high boiling point organic substance is likely to adhere. As
enlarged in Fig. 6, the surface of the intake valve 1 is coated with ceramic porous
carrier 17 having a limitless number of micropores 16, into which active substances
such as Pt, Pd and Rh are dissolved and carried, thereby forming the coating layer
15. The porous carrier 17 may be preferably made of oxide ceramics such as Al
2O
3, ZrO
2 and cordierite, and may be coated by surface treatment means such as thermal spray
and coating. If the surface of the intake valve 1 is made rough, peeling resistance
of the porous carrier 17 will be increased. If the porous carrier 17 comprises two
layer structure which comprises treating layer of Al
2O
3 and wash-coat layer of γ-Al
2O
3 applied thereon, the surface area of the micropores 16 will become larger, thereby
increasing carrying capability of the active substance.
[0019] The high boiling point organic substance included in the lubricating oil 8 which
is not washed down by the gasoline 11 and in the lubricating oil 8 which is scattered
by up-and-down movement of the intake valve 1 onto the opposite surface of the valve
head 1b in the vicinity of the injector 9 is absorbed on the active substance 18 in
the coating layer 15. When the intake valve 1 becomes a predetermined temperature
of 200 to 350° C, oxidation catalytic reaction occurs from heated portion, thereby
leaving the high boiling point organic substance from the active substance 18 and
dispersing it, so that high boiling point organic substance is neither carbonized
nor deposited on the surface of the valve head 1b.
[0020] The present invention may be applied to internal combustion engines other than gasoline
engine.
[0021] The foregoings merely relate to preferred embodiments of the invention. Various changes
and modifications may be made by person skilled in the art without departing from
the scope of claims wherein:
1. An intake valve device for preventing adhesion of deposits in an internal combustion
engine, the device comprising:
an intake poppet valve which comprises a valve head and a valve stem;
a valve guide in which the valve stem is slidably inserted; and
fuel injection means which injects fuel toward the valve head, either of contact surfaces
between the valve stem and the valve guide having an annular groove and an elongate
groove which communicates with the annular groove, a lower end of the elongate groove
opening toward an intake port in the vicinity of the fuel injection means.
2. An intake valve device as defined in claim 1 wherein the annular and elongate grooves
are formed on the contact surface of the valve guide to the valve stem.
3. An intake valve device as defined in claim 1 wherein the annular groove is formed
at lower portion at the contact surface of the valve guide.
4. An intake valve device as defined in claim 1 wherein the deposits comprise lubricating
oil invaded into a gap between the valve stem and the valve guide.
5. An intake valve device as defined in claim 1 wherein a coating layer having oxidation
catalytic function is formed on at least portion of the intake valve in the intake
port.
6. An intake valve device for preventing adhesion of deposits in an internal combustion
engine, the device comprising:
an intake poppet valve which comprises a valve head and a valve stem;
a valve guide in which the valve is slidably inserted; and
fuel injection means which injects fuel toward the valve head, either of contact surfaces
between the valve stem and the valve guide having a spiral groove, a lower end of
the spiral groove opening toward an intake port in the vicinity of the fuel injection
means.
7. An intake valve device as defined in claim 6 wherein the spiral groove is formed on
the contact surface of the valve guide to the valve stem.
8. An intake valve device as defined in claim 6 wherein the deposits comprise lubricating
oil invaded into a gap between the valve stem and the valve guide.
9. An intake valve device as defined in claim 6 wherein a coating layer having oxidation
catalytic function is formed on at least portion of the intake valve in the intake
port.