JP2015081512A - Valve gear of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lubricate a contact part between a rocker arm and a valve stem more efficiently.SOLUTION: A valve train structure of an engine includes: a rocker arm 20 supported by a support 11 of the engine in a freely swingable manner; and a valve member 5 in which an umbrella part 5a contacting and separating with/from a valve hole 4 of a valve is provided on one end "a" of a shaft-shaped valve stem 5b and the rocker arm 20 contacts with an end face of a cap 7 installed on an end face of the other end "b" or the other end "b". The rocker arm 20 includes an oil supply hole 22 passing through the rocker arm 20 and whose opening faces the end face of the other end "b" of the valve stem 5b or the end face of the cap 7, and the opening of the oil supply hole 22 faces the end face of the other end "b" of the valve stem 5b or the end face of the cap 7 at an eccentric position from a shaft center "c" of the valve stem 5b. In the shaft center "c" of the valve stem 5b, the other end "b" tilts to one side further than the one end "a", and the opening of the oil supply hole 22 faces the end face of the other end "b" or the end face of the cap 7 at an eccentric position toward the other side from the shaft center "c" of the valve stem 5b.

Description

  The present invention relates to a valve operating apparatus for an engine that opens and closes an intake / exhaust valve.

  Conventionally, there is a structure using a rocker arm as a valve operating device for opening and closing an intake / exhaust valve of an engine.

  The rocker arm is swingably supported by a support portion provided in the cylinder head of the engine, and repeats rocking as the cam rotates.

  As the intake / exhaust valve, 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-shaped 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 swinging end of the rocker arm is in contact with the other end of the valve stem, that is, the end face of the end opposite to the side where the umbrella is provided.

  When the rocker arm swings, the rocking end of the rocker arm moves toward the valve stem, and the other end of the valve stem is pressed against the urging force of the valve spring. Open the valve. Further, when the rocking end of the rocker arm moves away from the end of the valve stem, the valve member moves by the biasing force of the valve spring and closes the intake valve and the exhaust valve.

  Patent Document 1 discloses a technique in which a through hole for oil supply is provided at a rocking end of a rocker arm in order to oil lubricate a valve.

Japanese Patent Laid-Open No. 63-183407 (see FIGS. 12 and 13 in the drawings)

  According to Patent Document 1, the oil on the cylinder head side can be supplied to the valve side through the oil supply through hole provided in the rocker arm.

  However, the through-hole of the above-mentioned Patent Document 1 is provided in the rocker arm swinging end portion, particularly at a position sandwiching the side surface of the valve stem. The valve stem is not located directly below the oil supply hole, It falls to the combustion chamber side with almost no contact with the valve stem. For this reason, the function which lubricates the contact part of a rocker arm and a valve stem is not fulfilled. Since the abutting portion between the rocker arm and the valve stem is always in sliding contact with the rocker arm swinging, it is desirable that the rocker arm and the valve stem be efficiently lubricated to prevent wear. In addition, when a cap called an end cap is attached to the other end of the valve stem, it is desirable to efficiently lubricate the contact portion between the rocker arm and the cap.

  Accordingly, an object of the present invention is to more efficiently lubricate the contact portion between the rocker arm and the valve stem or the contact portion between the rocker arm and the cap attached to the valve stem.

  In order to solve the above-described problems, the present invention is provided with a rocker arm that is swingably supported by a support portion of a cylinder head, and an umbrella portion that contacts and separates from a valve hole of a valve at one end of a shaft-shaped valve stem. And a valve member that contacts the rocker arm against the end surface of the other end or the end surface of the cap attached to the other end, wherein the rocker arm penetrates the rocker arm and the opening thereof An oil supply hole facing the end face of the other end of the valve stem or the end face of the cap is provided, and the opening of the oil supply hole is located at an eccentric position from the axial center of the valve stem, or the end face of the other end of the valve stem or the end face of the cap Adopted the configuration that faces.

  At this time, the other end of the shaft center of the valve stem is inclined to one direction side from the one end, and the opening of the oil supply hole is located at a position eccentric from the shaft center of the valve stem to the other direction side. A configuration facing the end surface of the other end of the valve stem or the end surface of the cap can be employed.

  In each of these aspects, at the time of the minimum lift when the umbrella portion completely closes the valve hole, the opening of the oil supply hole corresponds to the end face of the rocker arm and the other end of the valve stem at the time of the minimum lift or the cap. A configuration may be adopted in which the valve stem faces the end surface of the other end of the valve stem or the end surface of the cap at a position on the other direction side than the contact point with the end surface.

  In each of these aspects, the inner surface of the oil supply hole is a tapered hole that gradually narrows from an opening to the surface opposite to the side facing the valve stem toward an opening to the surface on the valve stem side. A configuration can be employed.

  Further, in each of these aspects, the rocker arm has a concave oil sump on the surface opposite to the side facing the valve stem, and the oil supply hole is open to the oil sump. be able to.

  Furthermore, in each of these aspects, the rocker arm is swung by rotation of a camshaft, and the camshaft is driven by oil injected from a first oil supply portion provided on an oil pipe provided above or on the side of the camshaft. The oil pipe can be lubricated, and the oil pipe can include a second oil supply section that injects oil toward the oil supply hole of the rocker arm.

  According to this invention, the opening of the oil supply hole provided in the rocker arm is made to face the end surface of the valve stem or the end surface of the cap at a position eccentric from the axial center of the valve stem. The sliding contact portion between the end face and the end face of the cap can be more efficiently lubricated not only in the vicinity of the axis but also over a wide range.

  In addition, when the other end of the valve stem is inclined in a certain direction with respect to the one end, the opening of the oil supply hole is deviated from the axial center of the valve stem in the opposite direction, that is, in the other direction. Thus, the oil that has passed through the oil supply hole tends to reach the other end face of the valve stem or the entire end face of the cap.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view showing an engine valve operating apparatus according to an embodiment of the present invention. The rocker arm used for the valve gear of the engine of the embodiment is shown, (a) is a front view, (b) is a plan view. It is a principal part enlarged view which shows the contact part of a rocker arm and a valve stem, (a) is the example which comprises the end surface of the other end of a valve stem with an end cap, (b) is the example which does not use an end cap. It is. (A) and (b) are the principal part enlarged views which show the contact part of the rocker arm and valve stem of other embodiment, respectively. It is a principal part enlarged view which shows the contact part of the rocker arm and valve stem of other embodiment. The rocker arm used for the valve gear of the engine of other embodiments is shown, (a) is a front view and (b) is a top view.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is a valve gear 10 for 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. Although only one cylinder 1 is shown in the drawings, the engine may be a single cylinder or a multi-cylinder having a plurality of cylinders 1.

  As shown in FIG. 1, the cylinder 1 is provided with an 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. Yes. 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 gear 10 of the engine will be described by taking the intake port 3 as an example, but the same structure can be adopted also 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.

  As shown in FIG. 1, the valve gear 10 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. And a rocker arm 20 that is swingably supported by a support portion 11 provided in the cylinder 1 of the engine. The valve stem 5b is inserted into a valve insertion hole 5d formed in the cylinder 1 via a cylindrical valve stem guide 5c, and is movable back and forth in the axial direction with respect to the cylinder 1.

  The lower end of the valve spring 6, that is, the end close to the combustion chamber 2 is supported by the cylinder 1 via the valve spring seat 6a, and the upper end, that is, the end on the cylinder head side, is the retainer 6b and the cotter. It is fixed to the valve stem 5b via 6c. The retainer 6b is an annular member, and supports the upper end of the valve spring 6 at the outer periphery thereof. A valve stem 5b is inserted through the inner periphery of the retainer 6b via a cotter 6c.

  The cotter 6c is a split collet that is divided in half with the outer peripheral surface being a conical surface. The cotter 6c is in surface contact with the inner peripheral surface of the retainer 6b, which is also formed of a conical surface, and the outer peripheral surface of the valve stem 5b, and fixes the valve stem 5b and the retainer 6b. At this time, a retaining protrusion 6d is provided on the inner surface of the cotter 6c, and the retaining protrusion 6d enters the retaining recess 5e formed on the outer peripheral surface of the valve stem 5b to provide a retaining function in the axial direction. Demonstrate.

  In this embodiment, the valve stem 5b cannot rotate about the axis relative to the cotter 6c and the retainer 6b. However, the valve stem 5b can rotate relative to the axis relative to the cotter 6c and the retainer 6b. In some cases, a supporting structure is adopted.

  As shown in FIG. 2, the rocker arm 20 includes a longitudinal body member 20c formed by pressing or the like from the support end portion 20a to the swing end portion 20b, and is located in the middle in the longitudinal direction of the body member 20c. The roller 21 is slidably brought into contact with the cam 30 and functions as a power point. The roller 21 is rotatably supported by the main body member 20c by a support shaft 21a.

The support end portion 20a is provided with a fulcrum member 25 that fits into a recess of the support portion 11 provided on the cylinder 1 side and supports the rocker arm 20 so as to be swingable. In this embodiment, the inner surface of the concave portion of the support portion 11 is a spherical surface, and the outer surface of the fulcrum member 25 is a spherical surface that is slidably in contact with the inner surface of the concave portion. The end portion 20b swings up and down.
The fulcrum member 25 is fixed to the main body member 20c by a bolt 26 integral with the fulcrum member 25 being inserted into a hole provided in the main body member 20c and fastened by a nut 27 to be integrated.

  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 a of a shaft-shaped valve stem 5b. Further, the other end b of the valve stem 5 b extends to the rocking end 20 b of the rocker arm 2.

  An abutting member 25 that abuts against the other end b of the valve stem 5 b is provided at the rocking end 20 b of the rocker arm 20. The lower surface 24 of the contact member 25 is a slipper surface. The contact member 25 may be formed separately from the rocker arm 20 or may be integrally formed of the same material.

  In this embodiment, a metal concave cap 7 called an end cap is fitted to the other end b of the valve stem 5b. For this reason, the lower surface 24 of the contact member 25 of the rocker arm 20 contacts the end surface of the cap 7 of the valve stem 5b. That is, the lower surface 24 of the contact member 25 makes point contact with the end surface of the cap 7. The cap 7 is provided with an end surface member 7a that is circular in plan view and forms the end surface, and a cylindrical peripheral wall portion 7b that rises from the periphery of the end surface member 7a toward the opposite side of the end surface over the entire circumference.

  When the cap 7 is used without fitting the other end b of the valve stem 5b, the lower surface 24 of the contact member 25 directly contacts the end surface of the other end b of the valve stem 5b. That is, the lower surface 24 of the contact member 25 makes point contact with the end surface of the other end b of the valve stem 5b.

  When the cam 30 rotates together with the cam shaft 31 around the cam shaft 31, a pressing force acts on the roller 21 from the cam surface 30 a of the cam 30. By the action of the cam 30, the rocker arm 20 moves up and down in a direction connecting the cylinder head side and the combustion chamber 2 side with the support end portion 20a serving as a fulcrum.

  At this time, if the contact member 25 is lowered, the lower surface 24 of the contact member 25 presses the other end b of the valve stem 5b against the elastic force of the valve spring 6, and the valve member 5 is lowered and the valve The hole 4 is opened. When the contact member 25 is raised, the valve member 5 is raised by the elastic force of the valve spring 6 to close the valve hole 4. In this manner, the valve member 5 opens and closes the intake port 3 at a predetermined timing by the rotation of the cam 30 and the swing of the rocker arm 20 associated therewith.

  The transmission of power to the camshaft 31 is performed by connecting a sprocket provided on the camshaft 31 side and a sprocket provided on the crankshaft side with a timing chain or the like.

  Here, the contact member 25 of the rocker arm 20 is provided with an oil supply hole 22 that passes through the rocker arm 20 and faces the end surface of the cap 7.

  The opening of the oil supply hole 22 on the valve stem 5b side faces the end surface of the cap 7 at a position m eccentric from the axis c of the valve stem 5b, as shown in FIG. The position m is the intersection of the center line d of the oil supply hole 22 having a circular cross section and the end surface. FIG. 3 (a) shows the state when the umbrella portion 5a is at the minimum lift in which the valve hole 4 is completely closed. Reference sign p is a contact point of the rocker arm 20 at the time of the minimum lift.

By providing the oil supply hole 22, the contact portion between the rocker arm 20 and the end surface of the cap 7 can be more efficiently lubricated not only in the vicinity of the axis c but also over the entire end surface. In addition, since the center line d of the oil supply hole 22 and the opening on the valve stem 5b side are located eccentric from the axis c of the valve stem 5b, a higher lubricating effect can be expected. The eccentricity of the oil supply hole 22 is desirably realized at least at the time of the minimum lift when the umbrella portion 5a of the valve member 5 completely closes the valve hole 4, but at a timing other than the minimum lift, for example, at the time of the maximum lift It is desirable that the eccentricity continues even at an intermediate position.
Furthermore, since the cap 7 is rotatable around the axis c of the valve stem 5b with respect to the valve stem 5b, the oil tends to reach the entire end face along with the rotation.

  These effects are the same even when the cap 7 is omitted. In particular, when the valve stem 5b can rotate relative to the cylinder 1 around its axis, the same effect as the rotation of the cap 7 can be expected.

  As shown in FIG. 1, the camshaft 31 that swings the rocker arm 20 is lubricated by oil injected from a first oil supply portion 32 a provided in an oil pipe 32 provided above the camshaft 31. Yes.

  The oil pipe 32 is provided with a second oil supply portion 32 b that injects oil toward the oil supply hole 22 of the rocker arm 20. By providing the second oil supply part 32b, the supply of oil to the oil supply hole 22 of the rocker arm 20 can be sufficiently ensured. In this embodiment, the first oil supply part 32 a is a downward hole provided in the oil pipe 32 and directed to the cam 30, whereas the second oil supply part 32 b is directed to the oil supply hole 22 of the rocker arm 20. It consists of a laterally or diagonally downward hole.

  Further, the rocking end 20b of the rocker arm 20 is provided with a concave oil reservoir 23 on the upper surface thereof, that is, the surface opposite to the side facing the valve stem 5b. The oil supply hole 22 opens into the oil reservoir 23. For this reason, the oil can be smoothly supplied to the oil supply hole 22 and the valve stem 5b.

  When the cap 7 attached to the valve stem 5b is omitted, as shown in FIG. 3B, the opening of the oil supply hole 22 directly faces the end surface of the other end b of the valve stem 5b. Also in this case, since the opening of the oil supply hole 22 faces a position deviated from the axis c of the valve stem 5b, the end face of the other end b of the valve stem 5b is not only near the axis c but also the end face thereof. Lubrication can be performed more efficiently over the entire surface. The point that FIG.3 (b) shows the state at the time of the minimum lift is the same.

  Further, as shown in FIG. 1, the other end b of the valve stem 5b is inclined in one direction from the one end a, that is, the support end 20a side of the rocker arm 20 in the axis c of the valve stem 5b. . This gradient corresponds to an angle α with respect to the vertical direction.

  And the opening of the oil supply hole 22 is the end surface of the cap 7 or the valve stem 5b at a position eccentric from the axis c of the valve stem 5b in the other direction, that is, the side farther from the support end 20a of the rocker arm 20. It faces the end surface of the other end b. Since the end face of the cap 7 and the end face of the other end b of the valve stem 5b are both configured by a plane orthogonal to the axis c, the plane rises at an elevation angle α from one direction side to the other direction side. It is a gradient.

  Here, at the position where the opening of the oil supply hole 22 is decentered from the axis c of the valve stem 5b to the side opposite to the inclination direction of the axis c, that is, to the upper side of the upward slope of the end face (the other direction side). The oil that has passed through the oil supply hole 22 easily reaches the entire end surface of the cap 7 or the end surface of the other end b of the valve stem 5b. .

  During the minimum lift, the rocking end 20b of the rocker arm 20 is positioned relatively upward, and the rocking end 20b is close to the oil pipe 32 provided above the cam 30. For this reason, at least during the minimum lift at which oil is easily supplied, the opening of the oil supply hole 22 is offset from the axial center c of the valve stem 5b in the other direction, that is, at a position eccentric to the upper side of the upward slope of the end face. It is desirable to face the end face or the end face of the other end b of the valve stem 5b.

  4A shows the position of the opening of the oil supply hole 22 at the time of the minimum lift, and the end surface of the rocker arm 20 and the other end b of the valve stem 5b at the time of the minimum lift (the end surface of the cap 7 when the cap 7 is used). Of the other end b of the valve stem 5b than the contact point p (when the cap 7 is used, it faces the upper end of the gradient of the end surface of the cap 7) (point m) reference). At the maximum lift, the contact point q between the rocker arm 20 and the end surface of the other end b of the valve stem 5b (the end surface of the cap 7 when the cap 7 is used) moves toward the lower side of the gradient (the opening of the oil supply hole 22 is reduced). (Refer to the point n for reference).

  The opening of the oil supply hole 22 is always located at a position higher than the end point gradient than the contact point between the rocker arm 20 and the end surface of the other end b of the valve stem 5b (the end surface of the cap 7 when the cap 7 is used). Therefore, more sufficient oil lubrication is possible.

  4B shows the position of the opening of the oil supply hole 22 at the time of the minimum lift, and the end face of the rocker arm 20 and the other end b of the valve stem 5b at the time of the minimum lift (the end face of the cap 7 when the cap 7 is used). ) And the lower end of the end face of the other end b of the valve stem 5b (when using the cap 7, the lower end of the end face of the end face of the cap 7) and the axis of the valve stem 5b It faces the position above the center c (see point m). Similarly, at the time of maximum lift, the contact point q between the rocker arm 20 and the end surface of the other end b of the valve stem 5b (the end surface of the cap 7 when the cap 7 is used) moves toward the lower side of the gradient. The point where the opening of the oil supply hole 22 faces the end surface at the time of maximum lift is a point indicated by reference numeral n. The position indicated by the symbol n is the intersection of the center line d of the oil supply hole 22 and the end face.

  Since the opening of the oil supply hole 22 is positioned at an upper position of the gradient than the axis c of the valve stem 5b at least during the minimum lift, sufficient oil lubrication is possible.

Even in an engine in which the inclination of the axis c of the valve stem 5b and the inclination of the end face of the other end b of the valve stem 5b (the end face of the cap 7 when the cap 7 is used) are not set, The effect can be expected.
In particular, the opening of the oil supply hole 22 faces the end surface of the other end b of the valve stem 5b (the end surface of the cap 7 when the cap 7 is used) at a position eccentric from the axis c of the valve stem 5b. The effect of accelerating the supply of oil to both contact portions can be expected.
Further, when the cap 7 is rotatable around the axis c of the valve stem 5b, the cap 7 is omitted, and when the valve stem 5b is rotatable relative to the cylinder 1 around the axis c, the centrifuge is centrifuged. With the help of the force effect, oil can be smoothly supplied over a wide area.

  FIG. 5 omits the installation of the concave oil reservoir 23 provided at the rocking end 20 b of the rocker arm 20. Other configurations are the same as those in the above-described embodiment, and thus description thereof is omitted.

  FIG. 6 shows that the inner surface of the oil supply hole 22 is opened from the opening on the cylinder head side, that is, the surface opposite to the side facing the valve stem 5b, to the combustion chamber 2 side, that is, the surface on the valve stem 5b side. This is a tapered hole that gradually narrows toward.

  By making the shape of the inner surface of the oil supply hole 22 into a tapered hole that gradually narrows toward the valve stem 5b, the oil is easily guided to the oil supply hole 22, and the contact portion with the valve stem 5b and the cap 7 is more efficient. Lubrication.

  Further, by adopting the tapered hole, when the rocker arm 20 is lifted, that is, when the rocker arm 20 returns from the position corresponding to the maximum lift of the valve to the position corresponding to the minimum lift, the rocker arm 20 is swung. The accompanying inertia force works, and the oil in the oil supply hole 22 can be discharged toward the valve stem 5b without leaving any oil.

1 Cylinder 2 Combustion chamber 3 Intake port 4 Valve hole 5 Valve member (valve)
5a Umbrella portion 5b Valve stem 6 Valve spring 7 Cap 10 Valve operating device 11 Support portion 20 Rocker arm 21 Roller 22 Oil supply hole 23 Oil reservoir 24 Lower surface 25 Abutting member 30 Cam 31 Cam shaft 32 Oil pipe

Claims (6)

A rocker arm that is swingably supported by the support portion of the cylinder head;
An engine having an umbrella portion provided at one end of a shaft-shaped valve stem, which is in contact with or separated from a valve hole of the valve, and a valve member in which the rocker arm abuts against an end face of the other end or an end face of a cap attached to the other end. In the valve train structure,
The rocker arm includes an oil supply hole that penetrates the rocker arm and whose opening faces an end surface of the other end of the valve stem or an end surface of the cap,
The engine valve operating apparatus is characterized in that the opening of the oil supply hole faces the end face of the other end of the valve stem or the end face of the cap at a position eccentric from the axial center of the valve stem.   The other end of the shaft center of the valve stem is inclined in one direction with respect to the one end, and the opening of the oil supply hole is located at a position eccentric from the shaft center of the valve stem in the other direction. 2. The valve gear for an engine according to claim 1, wherein the valve gear faces the end face of the other end or the end face of the cap.   The opening of the oil supply hole is determined by the contact point between the rocker arm and the other end face of the valve stem or the end face of the cap during the minimum lift when the umbrella portion completely closes the valve hole. 3. The engine valve operating apparatus according to claim 1, wherein the valve stem faces an end face of the other end of the valve stem or an end face of the cap at a position on the other direction side.   The inner surface of the oil supply hole is a tapered hole that gradually narrows from an opening to a surface opposite to the side facing the valve stem toward an opening to the surface on the valve stem side. Item 4. The valve gear for an engine according to any one of Items 1 to 3.   The rocker arm includes a concave oil reservoir on a surface opposite to the side facing the valve stem, and the oil supply hole opens into the oil reservoir. 2. The valve gear for an engine according to claim 1.   The rocker arm is swung by rotation of a camshaft, and the camshaft is lubricated by oil sprayed from a first oil supply section provided on an oil pipe provided above or on the side of the camshaft. 6. The valve operating apparatus for an engine according to claim 1, wherein the oil pipe includes a second oil supply unit that injects oil toward an oil supply hole of the loker arm.

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