JP6179339B2 - Engine valve structure - Google Patents

Description

  The present invention relates to an engine valve structure.

  As an intake / exhaust valve for an engine, a valve (hereinafter referred to as a “valve member”) in which an umbrella portion which is a valve body portion is provided at one end of a shaft-like valve stem is used. The valve member is urged by a valve spring in a direction in which the umbrella portion closes the valve hole. The intake / exhaust valve opens and closes when the umbrella portion contacts and separates from the valve hole.

  The valve member resists the urging force of the valve spring by applying a pressing force to the other end of the valve stem, that is, the stem end opposite to the side where the umbrella portion is provided, by the action of the cam. Pressed toward the combustion chamber in the cylinder, the intake valve and exhaust valve are opened. When the pressing force is weakened, the valve member is moved by the urging force of the valve spring, and the intake valve and the exhaust valve are closed.

  The valve member is mounted with an annular retainer near the stem end via a cotter. Further, the valve stem is inserted into a valve insertion hole formed in the cylinder, and can advance and retract in the axial direction with respect to the cylinder.

  The lower end of the valve spring, that is, the end close to the combustion chamber is supported by the cylinder, and the upper end, that is, the end on the cylinder head side is supported by the retainer.

  The cotter is a split collet that is split in half with its outer surface being a conical surface. This cotter is in contact with the inner surface of the retainer, which also has a conical surface, and the outer surface of the valve stem. As a result, the cotter and the retainer rotate together around the axis. In addition, a retaining protrusion is provided along the circumferential direction on the inner surface of the cotter. The retaining protrusion enters a circumferential retaining groove formed on the outer surface of the valve stem so that the cotter and the retainer are It is prevented from coming off in the direction.

  In the valve stem, the outer surface of the valve stem and the inner surface of the cotter are not allowed to rotate relative to the cotter and retainer, and the outer surface of the valve stem and the inner peripheral surface of the cotter are not in close contact with each other. In some cases, it is supported so as to be relatively rotatable around the axis.

  Patent Document 1 discloses a technique in which an oil flow groove that allows oil to flow along the axial direction of a valve stem is provided on the inner surface of a cotter.

JP 2008-267296 A

  According to Patent Document 1, oil can flow down from the stem end side to the umbrella side through the oil flow groove in the cotter.

  However, the oil flow groove is provided so as to linearly connect the other end side end portion and the one end side end portion of the cotter. For this reason, the oil linearly passes through the oil flow groove from the other end side of the cotter to the one end side, and sufficient oil may not be supplied between the retaining protrusion and the retaining groove. .

  Accordingly, an object of the present invention is to efficiently lubricate a space between a cotter side retaining protrusion and a valve stem side retaining groove.

  In order to solve the above problems, the present invention provides a valve member having an umbrella portion at one end of a valve stem, a cotter disposed on the other end side of the valve stem, and a valve spring disposed on the outer periphery of the cotter. A plurality of annular retaining projections formed on the inner surface of the cotter, a plurality of annular retaining grooves formed on the outer surface of the valve stem and into which the plurality of retaining projections respectively enter, A communication groove formed on an outer surface of the valve stem and extending in the axial direction, and the communication groove includes at least one communication groove connecting at least the axially adjacent retaining grooves among the plurality of retaining grooves. The other communication groove extending from either one of the retaining grooves to which the communication groove is connected to the opposite side of the one communication groove, and the one communication groove and the other communication groove, Not in the circumferential direction It was adopted valve structure, characterized in that provided in the position.

  At this time, the other communication groove extends from either one of the retaining grooves to which the one communication groove is connected to the side opposite to the one communication groove, and is adjacent to the other side in the axial direction. It is possible to adopt a configuration that is connected to other retaining grooves.

  Further, the other communication groove extends from either one of the retaining grooves to which the one communication groove is connected to the side opposite to the one communication groove, and the opposite end is closed. The configuration can be adopted.

  The one communication groove and the other communication groove adopt a configuration in which the cross-sectional area of the flow path of the groove is larger than the side closer to the other end of the valve stem. be able to.

  The communication grooves are provided at least in three locations along the axial direction of the valve stem, the three communication grooves are connected via the retaining grooves, and the three communication grooves are The structure provided in the position shifted | deviated 120 degree | times to the circumferential direction in order along the axial direction is employable.

  Further, the cotter is attached to the valve stem by a split collet divided into two by the retainer from the outer diameter side to the inner diameter side. The pressing force between the divided collets is such that the inner surface of the divided collet is A configuration in which the pressing force applied to the outer surface of the stem is larger can be employed.

  According to this invention, one communication groove that connects between the axially adjacent retaining grooves on the outer surface of the valve stem and one retaining groove to which the one communicating groove is connected is connected to one communication groove. Another communication groove extending on the opposite side to the groove side is provided, and the positions of the one communication groove and the other communication groove are shifted in the circumferential direction. Oil is smoothly supplied to the stop groove. For this reason, it is possible to efficiently lubricate the space between the retaining protrusion of the cotter and the retaining groove of the valve stem.

It is front sectional drawing showing the valve structure of the engine of one Embodiment of this invention. The main part of a valve stem, a cotter, and a retainer is shown, (a) is a front view, (b) is a top view. It is a principal part expansion perspective view of a valve stem. (A) is a cut-away perspective view showing details of the valve stem, the cotter, and the retainer, and (b) is a plan view of the cotter before mounting.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is a valve structure of an automobile engine. In the drawings, only members and means directly related to the present invention are shown, and other members and the like are not shown.

  As shown in FIG. 1, the cylinder 1 has a port (intake port) 3 communicating with the combustion chamber 2 and a valve 5 (hereinafter referred to as “valve member 5”) for opening and closing the valve hole 4 of the intake port 3. Is provided. A fuel injection device (not shown) for injecting fuel into the intake port 3 is provided in the intake port 3, and fuel is injected into the intake air in the intake port 3 to form an air-fuel mixture. Hereinafter, the valve structure of the engine will be described taking the intake port 3 as an example, but the same structure is also adopted in the exhaust port. The engine is not limited to the fuel injection device provided in the intake port 3, but is provided in the combustion chamber 2 to inject fuel into the intake air in the combustion chamber 2 to form an air-fuel mixture. An injection engine may be used.

  The basic configuration of the valve and surrounding cylinders is the same as in the conventional example. That is, the valve structure includes a valve member 5 and an elastic member 6 (hereinafter referred to as “valve spring 6”) that urges the valve member 5 in the valve closing direction of the valve hole 4. The valve member 5 is provided with an umbrella portion 5a that functions as a valve body portion that contacts and separates from the valve hole 4 at one end of a shaft-shaped valve stem 5b. The other end 5c of the valve stem 5b extends to the cylinder head side.

  The valve stem 5b is inserted into a valve insertion hole formed in the cylinder 1 via a cylindrical valve stem guide and the like, and can advance and retract in the axial direction with respect to the cylinder 1.

  Further, the lower end of the valve spring 6 is supported by the cylinder 1, and the upper end thereof is supported by the lower surface of the outer peripheral portion of the retainer 7 made of an annular member. A valve stem 5 b is inserted into the inner peripheral portion of the retainer 7 through a cotter 8.

  The cotter 8 is a split collet that is divided in half with its outer surface being a conical surface. The cotter 8 is in surface contact with the inner surface of the retainer 7 which is also formed of a conical surface and the outer surface of the valve stem 5b.

  At this time, a retaining protrusion 9 is provided on the inner surface of the cotter 8, and this retaining protrusion 9 enters the retaining recess 10 formed on the outer surface of the valve stem 5b to provide a retaining function in the axial direction. Demonstrate.

  A valve lifter (not shown) fitted and fixed to the cylinder head is disposed on the other end 5c side of the valve stem 5b which is a stem end. When the cam comes into contact with the valve lifter, the pressing force is transmitted to the valve member 5.

  The transmission of power to the camshaft including the cam is performed by connecting a sprocket provided on the camshaft side and a sprocket provided on the crankshaft side with a timing chain or the like.

  A plurality of retaining protrusions 9 extending along the circumferential direction are provided on the inner surface of the cotter 8. In this embodiment, the retaining protrusions 9 are arranged in order from the other end 5c side toward the one end side that is the umbrella portion 5a side along the axial direction of the valve stem 5b. 9b and the third retaining protrusion 9c, a total of three, are provided at equal intervals. All the retaining protrusions 9 are annular protrusions over the entire circumference in the circumferential direction. In addition, the mutual space | interval between the 1st retaining protrusion 9a, the 2nd retaining protrusion 9b, and the 3rd retaining protrusion 9c and the width | variety of a protrusion can be suitably set according to the specification of a valve | bulb.

  A plurality of retaining grooves 10 are provided on the outer surface of the valve stem 5b in the circumferential direction into which the plurality of retaining protrusions 9 are respectively inserted. In this embodiment, the retaining groove 10 includes a first retaining groove 10a, a second retaining groove 10b, and a third retaining member in order from the other end 5c side to the umbrella portion 5a side along the axial direction of the valve stem 5b. A total of three retaining grooves 10c are provided at equal intervals. All the retaining grooves 10 are annular grooves over the entire circumference in the circumferential direction.

  The first retaining projection 9a corresponds to the corresponding first retaining groove 10a, the second retaining projection 9b corresponds to the corresponding second retaining groove 10b, and the third retaining projection 9c corresponds to the corresponding third retaining groove 10c. By entering each, the cotter 8 and the retainer 7 have a three-bead specification that prevents the valve stem 5b from coming out toward the other axial end 5c.

  A concave groove 14 is formed between the first retaining protrusion 9a, the second retaining protrusion 9b, and the third retaining protrusion 9c on the cotter 8 side, from the other end 5c side toward the umbrella portion 5a side. In order, a first groove 14a and a second groove 14b are formed. The first stem groove 10a, the second retaining groove 10b, and the third retaining groove 10c on the valve stem 5b side are respectively provided with protrusions 13 from the other end 5c side toward the umbrella portion 5a side. The 1st protrusion 13a and the 2nd protrusion 13b are formed in order.

  Therefore, the first retaining protrusion 9a, the second retaining protrusion 9b, and the third retaining protrusion 9c enter the corresponding first retaining groove 10a, second retaining groove 10b, and third retaining groove 10c, respectively. If it puts in, the 1st protrusion 13a and the 2nd protrusion 13b will respectively enter into the 1st ditch | groove 14a and the 2nd ditch | groove 14b, and will mutually mesh | engage.

  The cotter 8 and the retainer 7 are in a state in which the conical surface 11 of the outer surface of the cotter 8 is in surface contact with the conical surface 12 of the inner surface of the retainer 7, and the cotter 8 and the retainer 7 are integrally rotated around the axis. The cotter 8 and the retainer 7 are not relatively rotatable about the axis.

  The valve stem 5b is supported so as to be relatively rotatable around the axis with respect to the cotter 8 and the retainer 7. The split collet divided into two that constitutes the cotter 8 is in a state before being attached to the valve stem 5b, and the split surfaces 8a and 8b on both sides across the axis of the valve stem 5b (the angle α in FIG. 4B). Reference) are not on the same plane, and the divided surfaces 8a and 8b on both sides of the divided collet are set at an angle slightly smaller than 180 degrees around the axis of the valve stem 5b in the plan view. .

  When the two split collets are tightened from the outer diameter side to the inner diameter side by the retainer 7 and elastically deformed, the surface directions of the two split surfaces 8a and 8b are positioned at 180 degrees centering on the axis of the valve stem 5b. It becomes a relationship, that is, it is located on the same plane (see FIG. 1B). Accordingly, the divided surfaces 8a and 8b of the two divided collets are in surface contact with each other, and the cotter 8 allows relative rotation between the valve stem 5b and the cotter 8 without excessively pressing the outer surface of the valve stem 5b. It has become.

  That is, the cotter 8 has a split collet divided into two by the retainer 7 and tightened from the outer diameter side to the inner diameter side and attached to the valve stem 5b. The pressing force of the contact portion between the divided collets is the inner surface of the divided collet. Is larger than the pressing force applied to the outer surface of the valve stem 5b.

  A communication groove extending in the axial direction is provided on the outer surface of the valve stem 5b. The communication groove includes a both-end connection communication groove 20 whose both ends are connected to the retaining groove 10 and a one-end closed communication groove 21 whose only one end is connected to the retaining groove 10.

  Between the first retaining groove 10a and the second retaining groove 10b, a both-end connecting communication groove (the one communicating groove) 20a is provided. Further, a both-end connection communication groove (the other communication hole) 20b is provided between the second retaining groove 10b and the third retaining groove 10c.

  In addition, one end closing communication groove extending from the first retaining groove 10a to which the both end connection communication groove 20a (the one communication groove) is connected to the side opposite to the both end connection communication groove 20a side, that is, the other end 5c side ( The other communication groove) 21a is provided. The one end open communication groove 21a extends from the first retaining groove 10a to the other end 5c side, and is closed in a dead end manner without the other end 5c side being connected to the groove. The end of the one end open communication groove 21 a on the other end 5 c side is not covered with the cotter 8 and is desired in the space inside the cylinder 1.

  In addition, a one-end closed communication groove 21b extending from the third retaining groove 10c to which the both-end connection communication groove 20b is connected to the opposite side of the both-end connection communication groove 20b, that is, the umbrella portion 5a side is provided. The one-end closed communication groove 21b extends from the first retaining groove 10a toward the umbrella portion 5a and is closed in a dead end manner without the end portion of the umbrella portion 5a being connected to the groove. The end of the one end open communication groove 21b on the umbrella portion 5a side is not covered with the cotter 8, but is desired in the space in the cylinder 1.

  At this time, as described above, when the both-end connection communication groove 20a is one communication groove in the claims, the both-end connection communication grooves 20b correspond to the other communication grooves in the claims. When 20b is considered as one communication groove in the claims, the one-end closed communication groove 21b corresponds to the other communication groove in the claims.

That is, the other communication hole adjacent in the axial direction may be the both-end connection communication groove 20 with respect to one communication groove (both-end connection communication groove 20) connecting the retaining grooves 10 adjacent in the axial direction. However, the one-end closed communication groove 21 may be used.
Further, the number of communication grooves can be freely set according to the number of steps of the retaining groove 10 formed annularly around the axis of the valve stem 5b, and the two end connection communication grooves 20 set as other communication holes can be connected to one communication hole. You may further set the both-ends connection communication groove | channel 20 or the one end obstruction | occlusion communication groove | channel 21 as another communication hole with respect to the one communication hole as a hole.

In this embodiment, three retaining grooves 10 are provided along the axial direction, and one end connection communication groove 20 is provided between each of the adjacent retaining grooves 10, but the number of both end connection communication grooves 20 is as follows. The number of steps of the retaining groove 10 formed in the valve stem 5b can be set freely. For example, if the number of steps of the retaining groove 10 is two, one end connecting communication groove 20 is provided between the retaining grooves 10, and one end closed communication with each retaining groove 10 or one retaining groove 10. For example, if the number of steps of the retaining groove 10 is four, one end connecting communication groove 20 is provided between adjacent retaining grooves 10, and both ends One end closing communicating groove 21 may be connected to the retaining groove 10 or the retaining groove 10 at one end.
Further, a plurality of both end connection communication grooves 20 may be provided between the pair of retaining grooves 10 along the circumferential direction. In addition, a plurality of both-end closed communication grooves 21 may be provided in one retaining groove 10 along the circumferential direction.

  As a result, all the adjacent retaining grooves 10 are connected by the both-end connecting communication grooves 20; 20a, 20b, and one end is closed from the retaining groove 10 on the most other end 5c side toward the other end 5c side. Communication grooves 21; 21a are arranged. Also, from the retaining groove 10 closest to the umbrella part 5a, one end closed communication grooves 21; 21b are arranged toward the umbrella part 5a side.

  As a result, the oil supplied from the cylinder head side, as shown by the arrow in FIG. It flows down to the umbrella portion 5a via the communication groove 20b, the third retaining groove 10c, and the one-end closed communication groove 21b. For this reason, it is possible to efficiently lubricate between the retaining protrusion 9 and the retaining groove 10.

  The flow path alternately passes through the communication groove and the retaining groove 10 and the flow direction alternately changes stepwise in the axial direction and the circumferential direction also contributes to smooth oil circulation.

  Further, when the valve stem 5b rotates around the axis, the oil in the retaining groove 10 is promoted to move along the flow path due to the inertia at the time of rotation. Further, when the valve member 5 moves in the axial direction, the movement of the oil in the communication groove along the flow path is promoted by the inertia of the axial movement.

  At this time, it is desirable that the communication groove is formed so that the cross-sectional area of the flow path of the groove is larger than the side far from the other end 5c of the valve stem 5b. In this embodiment, the groove width is set to be gradually reduced in the order of the one-end closed communication groove 21a, the both-end connection communication groove 20a, the both-end connection communication groove 20b, and the one-end closed communication groove 21b. For this reason, the flow path tapers from the other end 5c side toward the umbrella portion 5a side, and oil is easily guided to the umbrella portion 5a side.

  In order to make the cross-sectional area of the flow path of the communication groove larger on the side closer to the other end 5c of the valve stem 5b than on the far side, for example, one end closed communication groove 21a, both end connection communication groove 20a, both end connection communication You may set so that the depth of a groove | channel may become shallow gradually in order of the groove | channel 20b and the one end obstruction | occlusion communication groove | channel 21b. Further, the difference in the cross-sectional area of the flow path may be set by using the difference in the groove width between the communication grooves and the difference in the depth of the groove together.

In this embodiment, the communication groove is provided at a position shifted 120 degrees in the circumferential direction in order along the axial direction from the side closer to the other end 5c of the valve stem 5b to the side farther from the side. That is, the one-end closed communication groove 21a, the both-end connection communication groove 20a, the both-end connection communication groove 20b, and the one-end closed communication groove 21b are provided at positions shifted by 120 degrees clockwise in plan view in the circumferential direction.
For this reason, the circumferential distance between all adjacent communication grooves, that is, the movement distance in the circumferential direction until the oil that has exited one communication groove reaches the next communication groove is uniform, and smooth oil induction is achieved. Is possible.

  However, the direction in which the communication groove is provided can be freely set according to the required degree of lubrication. For example, the communication groove may be provided at a position shifted by 120 degrees counterclockwise in a plan view in the circumferential direction from the side closer to the other end 5c of the valve stem 5b to the side farther from the side. Further, for example, the communication groove may be provided at a position shifted by 180 degrees in the circumferential direction from the side closer to the other end 5c of the valve stem 5b to the side farther from the side.

  In this embodiment, the both-end connection communication groove 20 and the one-end closed communication groove 21 are set as the communication grooves. However, depending on the specification of the valve, the one-end closed communication groove 21 may be omitted. In other words, the one-end closed communication groove 21 has an end-closed communication groove 21a on the other end 5c side that promotes the inflow of oil into the communication groove and the retaining groove, and the one-end closed communication groove 21b on the umbrella 5a side has a communication groove. This contributes to preventing oil from staying in the retaining groove. However, when these functions are not desired, the installation of one or both of the one-end closed communication grooves 21a and 21b can be omitted.

  In this embodiment, the valve stem 5b employs a structure that can rotate relative to the cotter 8 and the retainer 7 around the axis. However, the valve stem 5b cannot rotate relative to the cotter 8 and the retainer 7 around the axis. The communication groove of the present invention can also be employed in the structure that supports the above.

  In this embodiment, as a valve operating device for moving the valve member 5 in the axial direction, the cam is brought into contact with the valve lifter on the stem end side to transmit the pressing force to the valve member 5. In addition, other valve operating devices such as a structure in which a pressing force is transmitted to the valve member 5 by swinging a rocker arm by the action of a cam may be employed.

1 Cylinder 2 Combustion chamber 3 Port 4 Valve hole 5 Valve member (valve)
5a Umbrella 5b Valve stem 5c Stem end (other end)
6 valve spring 7 retainer 8 cotter 9 retaining projection 9a first retaining projection 9b second retaining projection 9c third retaining projection 10 retaining groove 10a first retaining groove 10b second retaining groove 10c third retaining Grooves 11 and 12 Conical surface 13 ridge 13a first ridge 13b second ridge 14 groove 14a first groove 14b second groove 20, 20a, 20b communication groove (both ends connection communication groove)
21, 21a, 21b communication groove (one-end closed communication groove)

Claims (6)

A valve member having an umbrella at one end of the valve stem;
A cotter disposed on the other end of the valve stem;
A retainer disposed on an outer periphery of the cotter and supporting a valve spring;
A plurality of annular retaining protrusions formed on the inner surface of the cotter;
A plurality of annular retaining grooves formed on the outer surface of the valve stem and into which the plurality of retaining projections respectively enter;
A communication groove formed on the outer surface of the valve stem and extending in the axial direction;
The communication groove is
One communication groove connecting at least the axially adjacent retaining grooves among the plurality of retaining grooves;
From one of the retaining grooves to which the one communication groove is connected, another communication groove extending to the opposite side of the one communication groove, and
The valve structure characterized in that the one communication groove and the other communication groove are provided at positions shifted in the circumferential direction.   The other communication groove extends from one of the retaining grooves to which the one communication groove is connected to the side opposite to the one communication groove, and is adjacent to the other side in the axial direction on the opposite side. The valve structure according to claim 1, wherein the valve structure is connected to a retaining groove.   The other communication groove extends from either one of the retaining grooves to which the one communication groove is connected to the side opposite to the one communication groove, and the opposite end is closed. The valve structure according to claim 1.   The one communication groove and the other communication groove are formed so that a cross-sectional area of a flow path of the groove is larger than a side far from the other end of the valve stem than a side far from the other end. Item 4. The valve structure according to any one of Items 1 to 3. The communication groove is provided in at least three locations along the axial direction of the valve stem, and the three communication grooves are connected via the retaining groove,
The valve structure according to any one of claims 1 to 4, wherein the three communication grooves are provided at positions shifted by 120 degrees in the circumferential direction in order along the axial direction. The cotter is attached to the valve stem with a split collet divided into two from the outer diameter side to the inner diameter side by the retainer,
6. The valve structure according to claim 1, wherein the pressing force between the divided collets is larger than the pressing force applied to the outer surface of the valve stem by the inner surface of the divided collet. .

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