JP3843925B2 - Engine valve gear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a valve operating apparatus for an engine, and more particularly to a valve operating for an engine comprising a center tappet and side tappets on both sides in the cam axial direction. Relates to the device.
[0002]
[Prior art]
As a direct type valve operating device that directly drives the intake and exhaust valves of engines for automobiles via tappets, the tappet consists of a center tappet and side tappets on both sides in the cam axial direction. Are connected to both side tappets in the vicinity of the end on the valve side by a connecting portion extending substantially perpendicularly, and a connecting portion with the valve stem is provided on the surface of the connecting portion on the opposite cam side, and between the side tappets on both sides. A center tappet is incorporated so that it can be moved relative to the outer peripheral surface, and the outer peripheral surface is formed into a substantially cylindrical shape. The center tappet can be coupled and detached by a lock mechanism, and a center cam and a side cam having different cam profiles are provided, 2. Description of the Related Art Conventionally, a valve operating device that can change the operation characteristics of a valve by a detachment operation is known (see, for example, Patent Documents 1 and 2). As the tappet, the side tappet has sliding contact surfaces extending in the tappet shaft direction parallel to the cam shaft direction at both ends in the direction orthogonal to the cam shaft, and the center tappet is side-mounted at both ends in the direction orthogonal to the cam shaft. A tappet outer peripheral surface formed of a center tappet and side tappets on both sides is formed in a substantially cylindrical shape, having a protruding portion provided with a sliding contact surface that comes into contact with the sliding contact surface of the tappet. Is known (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-329907 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-54413
[Problems to be solved by the invention]
By the way, the tappet of the valve operating device is pushed by the cam and slides in the tappet guide hole. The tappet contacts the cam at the top cam contact surface, and the cam contact surface is perpendicular to the cam shaft. Since the cam surface is pressed while being in sliding contact, a force for tilting the tappet with respect to the tappet guide hole in a direction perpendicular to the cam shaft is generated during driving. And if the tappet falls by this, the local surface pressure with the inner surface of the tappet guide hole increases, and there is a possibility that uneven wear occurs.
[0005]
In particular, as described above, the tappet is composed of the center tappet and the side tappets on both sides in the cam axis direction, the center tappet is substantially I-shaped in plan view, and the side tappet and the center tappet are slid parallel to the cam axis direction. When the side tappet is abutted in the direction perpendicular to the cam shaft on the contact surface, when the side tappet is pushed by the cam, the force is transmitted from the side tappet to the center tappet via the valve side end of the sliding contact surface, and the center tappet skirt When the lower end of the portion is pushed or when the cam pushes the center tappet, the center tappet is tilted. For this reason, the local surface pressure between the center tappet and the inner surface of the tappet guide hole is increased, and there is a risk of uneven wear.
[0006]
The present invention has been made in view of these problems, and is composed of a center tappet and side tappets on both sides in the cam shaft direction, and the side tappet and the center tappet are slidable contact surfaces parallel to the cam shaft direction and the cam shaft. It is an object of the present invention to prevent uneven wear by preventing an increase in local surface pressure due to tilting of a tappet when a cam is driven in a valve operating apparatus using a tappet that abuts in an orthogonal direction.
[0007]
[Means for Solving the Problems]
The valve operating apparatus for an engine according to the present invention includes a tappet that contacts a cam and slides in a tappet guide hole to drive a valve, a center tappet positioned in the center of the cam shaft direction, and side surfaces positioned on both sides of the cam shaft direction. A tappet is formed on both ends of the side tappet in a direction perpendicular to the cam shaft, and a sliding contact surface extending in the tappet axis direction is formed in parallel with the cam shaft direction. Formed in a substantially I shape in plan view having protrusions protruding toward the side tappets on both sides and extending in the direction of the tappet axis, the inner side surfaces of the protrusions facing the direction perpendicular to the cam axis are camshafts. Parallel and extending in the direction of the tappet axis, it is a sliding surface that contacts the sliding surface of the side tappet. The center tappet and the side tappet can be moved relative to each other in the tappet sliding direction and locked. The cam is divided into a center cam corresponding to the center tappet and a pair of side cams corresponding to the side portions of the side tappet, and the cam profile is different between the center cam and the pair of side cams. The valve operating device of the engine that can change the operating characteristics of the valve by coupling or releasing operation of the lock mechanism, the outer peripheral surface of the tappet composed of the center tappet and the side tappets on both sides is substantially cylindrical, The side tappets on both sides are connected by a connecting portion that extends substantially perpendicular to both side tappets in the vicinity of the end on the valve side, and the connecting portion has a contact portion with the valve stem on the surface on the side opposite to the cam. Lost motion spring seats are projected and formed on both sides in the direction perpendicular to the camshaft of each part. Two lost motion springs that press the center tappet against the center cam when the locking mechanism is disengaged are arranged between the center tappet and the cam slide contact portion of the center tappet. The lost motion spring is formed on the valve end of the side tappet facing the projection of the center tappet, extending beyond the surface connecting the sliding surface of the side tappet in the cam axis direction. from Hanben side of the seat portion to an end of the valve side, characterized in that the notch-shaped relief portion so as to form a predetermined gap between the projections of the center tappet is formed.
[0008]
In this way, a notch-shaped relief portion is formed at a portion facing the protrusion portion of the center tappet at the valve-side end portion of the side tappet so as to form a predetermined interval with the protrusion portion of the center tappet. Thus, when the tappet is tilted during driving, the end of the side tappet can escape to the end of the valve side, and the end of the side tappet does not contact the center tappet. However, it is possible to bend, and an increase in surface pressure between the lower end of the center tappet and the inner surface of the tappet guide hole is prevented. Therefore, it is possible to prevent uneven wear due to the tappet falling during driving.
[0009]
In this valve operating apparatus, the outer peripheral surface of the tappet composed of the center tappet and the side tappets on both sides is substantially cylindrical, and the side tappets on both sides are substantially perpendicular to both side tappets in the vicinity of the end on the valve side. The connecting part has a contact part with the valve stem on the surface on the side opposite to the cam, and the lost motion spring seat part protrudes on both sides in the direction perpendicular to the cam shaft of the connecting part. it is, between the cam sliding portion back surface of the lost motion spring seat portion and the center tappet, in which two of the lost motion spring for pressing the center tappet to Sentakamu upon withdrawal operation of the locking mechanism is arranged. Then, in particular, they lost motion spring seat portion, in which are formed projecting in a direction perpendicular to the cam shaft beyond a plane connecting in plan view the sliding surface of both sides tappet camshaft direction. In this case, the slidable contact surface needs to be cut with a high degree of accuracy, and if the slidable contact surface is provided to the end of the side tappet on the valve side, it must be processed away from the lost motion spring seat. There is a possibility that the lost motion spring seat part may be scraped off, and it is difficult to process the sliding contact surface. However, as described above, cut the part on the valve side end of the side tappet facing the protrusion of the center tappet. By forming the notch-shaped relief part, the sliding contact surface reaches to the front of the relief part, and it is not necessary to process by avoiding the lost motion spring seat part, making it easy to process the sliding contact surface and lost motion during cutting. The spring seat is not cut off.
[0010]
If two lost motion springs are used and distributed to both sides in the direction perpendicular to the camshaft, the spring can be placed avoiding the lock mechanism located in the center of the tappet, increasing the flexibility of the spring length. The spring can be lengthened to increase the stroke difference between the side tappet and the center tappet. Then, the lost motion spring seat portion is formed so as to protrude in a direction perpendicular to the cam shaft beyond the surface connecting the sliding contact surfaces of both side tappets in the cam shaft direction in plan view. It becomes easy to secure a space to be disposed between the back surface of the center tappet and the cam sliding contact portion.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
1 to 13 shows a valve operating apparatus for an engine according to the embodiment of this invention. FIG. 1 is a front view showing a cross section perpendicular to a cam shaft of a main part of a valve operating apparatus, FIG. 2 is a side view showing a main part of the valve operating apparatus in a cross section parallel to the cam shaft, and FIG. FIG. 4 is a front view longitudinal sectional view showing a central section perpendicular to the tappet cam axis, FIG. 5 is a bottom view of the tappet, and FIG. 6 is a side sectional longitudinal view showing a central section parallel to the tappet cam axis. 7 is a cross-sectional view in plan view passing through the center of the lock mechanism of the tappet, FIG. 8 is a vertical cross-sectional view in side view showing a central cross section parallel to the cam shaft of the side tappet of the tappet, and FIG. 9 is a side tappet of the tappet. FIG. 10 is a side view of a single tappet side tappet, FIG. 11 is a bottom view of a single side tappet, FIG. 12 is a plan view of a single center tappet, and FIG. 13 is a front view of a single center tappet. .
[0013]
In FIGS. 1 and 2, 1 is a cam carrier disposed on the cylinder head of the engine, 2 is a camshaft, 3 is a tappet, 4 is a tappet guide hole provided in the cam carrier, 5 is a valve (intake valve or Exhaust valve). As shown in FIGS. 3 to 7, the tappet 3 is composed of a center tappet 31 and a side tappet 32. In contrast to this tappet 3, the camshaft 2 has a cam with a high lift amount at a portion corresponding to the center tappet 31. A high-speed center cam 21 having a profile is provided, and low-speed side cams 22 and 23 having a low lift cam profile are provided at portions corresponding to the side tappets 32 on both sides of the center cam 21. The side cams 22 and 23 sandwiching the center cam 21 may be stop cams having the same cam profile with a minute lift amount that substantially stops the valve operation.
[0014]
The tappet 3 is generally cylindrical as a whole, the center tappet 31 forms a central portion in the direction of the cam shaft (the central axis of the camshaft 2), and the side tappet bodies 32a and 32b of the side tappet 32 form side portions. Is done. The upper surface of the center tappet 31 forms a substantially rectangular planar center cam contact surface that is long in the cam sliding contact direction (a direction orthogonal to the axis of the cam shaft in plan view). The upper surfaces of 32a and 32b constitute substantially crescent-shaped planar side cam contact surfaces that fill in both sides of the center cam contact surface to form a circular cam contact surface as a whole.
[0015]
As shown in FIGS. 8 to 11, the side tappet 32 has a pair of side tappet bodies 32 a and 32 b that constitute the side cam abutment surface, and the end on the side opposite to the cam abutment surface (hereinafter referred to as “anti-cam side”). In the vicinity of the portion, it is integrally connected by a connecting portion 32c having a contact portion 33 with the valve stem end 51 (see FIG. 1) on the lower surface, and is formed in a substantially U shape in side view. Lost motion spring seat portions 34a and 34b that protrude beyond the sliding contact surfaces of sliding contact portions 42a, 42b, 42c, and 42d, which will be described later, in plan view, are provided at both ends in the direction orthogonal to the cam shaft. Lost motion springs 35a and 35b are installed in the motion spring seat portions 34a and 34b, and from there, as shown in FIGS. 3 to 7, a space between the side tappet bodies 32a and 32b is set. Tatapetto 31 is incorporated. In the tappet 3, the contact portion 33 on the lower surface of the connecting portion 32 c of the side tappet 32 contacts the stem end 51 of the valve 5 through the shim 6.
[0016]
As shown in FIGS. 12 to 13, the center tappet 31 is a pair of symmetrically extending vertically downward from the edge on the side (both long sides) along the cam sliding contact direction of the substantially rectangular flat center cam contact surface. And a pair of arcuate outer peripheral surfaces 37a that extend symmetrically vertically downward from the end edges (both short sides) in the direction orthogonal to the camshaft. 37b, and at both ends in a direction perpendicular to the cam shaft, the outer side continuously protrudes from the outer peripheral surface in an arc shape to the side tappet 32 (side tappet bodies 32a, 32b) side, and the inner side is the cam shaft. Projecting portions 38a, 38b, 38c projecting from the front and rear end surfaces 36a, 36b substantially perpendicularly to the cam shaft direction so as to constitute a sliding contact surface facing the direction perpendicular to the cam shaft direction and extending in the tappet shaft direction. 38d is in the tappet axial direction It formed to project over the entire length, and is configured in a planar view substantially I-shaped as a whole. A through hole 39 is formed in the upper center of the center tappet 31 so as to penetrate between the front and rear end faces 36a, 36b in parallel with the cam shaft direction.
[0017]
Further, the side tappet 32 has a pair of inward end surfaces 40a and 40b that are substantially U-shaped in a side view as described above, and extend vertically opposite to the inside of the pair of left and right side tappet bodies 32a and 32b. The side cam contact surface has outer circumferential surfaces 41a and 41b having arc-shaped cross sections extending symmetrically in the front-rear direction from the edge on the outer end side in the cam shaft direction, and the cam sliding direction of the side tappet bodies 32a and 32b. At both ends in the direction (perpendicular to the cam shaft), a sliding contact surface extending in the tappet axis direction parallel to the cam shaft direction so as to be in sliding contact with the sliding contact surfaces of the projections 38a, 38b, 38c, 38d of the center tappet 31. Sliding contact portions 42a, 42b, 42c, and 42d provided with are formed. The side tappet 32 has a through hole 39 in the center tappet 31 when the center cam abutment surface of the center tappet 31 and the side cam abutment surface of the side tappet 32 are flush with each other in the upper center of the side tappet bodies 32a and 32b. Through-holes 43a and 43b penetrating from the inner end faces 40a and 40b to the outer peripheral faces 41a and 41b are provided in parallel with the cam shaft direction so as to communicate with each other without a step.
[0018]
Further, the both side tappet bodies 32a and 32b of the side tappet 32 have lost motion spring seat portions 34a and 34b at the valve-side end portions facing the projections 38a, 38b, 38c and 38d of the center tappet 31. The notch-shaped relief portions 85a, 85b, 85c, and 85d are formed so as to form a predetermined distance from the protrusions 38a, 38b, 38c, and 38d of the center tappet 31 from the upper side (counter valve side) to the lower end. Is formed.
[0019]
In the center tappet 31 and the side tappet 32, the center cam sliding contact surface of the center tappet 31 contacts the base circle portion of the center cam 21, and the side cam sliding contact surface of the side tappet 32 contacts the base circle portion of the side cams 22 and 23. In this state, the center cam slidable contact surface of the center tappet 31 and the side cam slidable contact surface of the side tappet 32 are substantially flush, and in this state, the through hole 39 of the center tappet 31 and the through holes 43a and 43b of the side tappet 32 are in a straight line. Communicate with.
[0020]
In addition, a hydraulic plunger 71 is built in the through hole 43 b of one side tappet body 32 b of the side tappet 32 so as to protrude into the through hole 56 of the center tappet 31 by hydraulic pressure, and a through hole 39 that penetrates the center tappet 31. Includes a lock pin 72 that is pushed by the hydraulic plunger 71 so as to protrude into the through hole 43a of the other side tappet body 32a of the side tappet 32, and the lock pin 72 is connected to the center tappet 31 and the side tappet 31. A return spring 73 that urges the tappet 32 to a position where the tappet 32 is separated from each other and can be relatively moved in the tappet sliding direction is incorporated.
[0021]
The end surface of the center tappet 31 is formed in the through hole 39 of the center tappet 31 at a portion that opens to the front and rear end surfaces 36a, 36b facing the inner end surfaces 40a, 40b of the side tappet bodies 32a, 32b. Bushings 74 and 75 are respectively inserted and fixed so as to be flush with 36a and 36b. Among them, the bush 75 fixed to the end portion on the hydraulic plunger 71 side abuts on the flange 76 on the outer periphery of the lock pin 72 and restricts the movement of the lock pin 72 to the hydraulic plunger 71 side. Further, the bush 74 fixed to the other end holds the return spring 73 in a compressed state between the bush 74 and the flange 76 on the outer periphery of the lock pin 72.
[0022]
Further, bushes 77 and 78 are respectively inserted and fixed in the through holes 43a and 43b on the side tappet 32 side. Among them, the bush 78 inserted and fixed in the through hole 43b of the side tappet body 32b in which the hydraulic plunger 71 is built is closed by the end wall 78a on the outer peripheral side of the tappet, and the inside is fitted to slide-fit the hydraulic plunger 71. A joint hole 78b is formed. The bush 77 inserted and fixed in the through hole 43a of the other side tappet body 32a has a fitting hole 77b for fitting the end of the lock pin 72 on the inner side in the axial direction. It functions as a stopper that regulates The bushes 77 and 78 on the side tappet 32 side have end portions on the center tappet 31 side protruding from the through holes 61a and 61b by predetermined dimensions, respectively, and are inserted into end faces of the bushes 74 and 75 inserted and fixed in the through hole 56 of the center tappet 31. Each is opposed to each other with a predetermined interval.
[0023]
Further, the outer peripheral surface 41a of the side tappet body 32a on which the bush 77 is inserted and fixed is cut out vertically at a portion where the through hole 43a is opened, and the bush is formed on the notched portion. A rotation stop member 87 supported by a pin 86 supported by 77 is swingably mounted to prevent the tappet 3 from rotating in the circumferential direction.
[0024]
Further, the center tappet 31 includes both side tappets 32 in the camshaft direction in the portion along the lower part of the through hole 39 of both end faces 54a and 54b facing both side tappet bodies 32a and 32b of the side tappet 32. By projecting toward the inner end faces 40a, 40b of the bodies 32a, 32b, the end portions of the bushes 77, 78 projecting inwardly attached to the through holes 43a, 43b of both side tappet bodies 32a, 32b are engaged. Locking portions 89a and 89b to be stopped are provided. When these engaging portions 89a and 89b are engaged with the bushes 77 and 78 on the side tappet 32 on both sides, the center tappet 31 is restricted from moving upward in the tappet sliding direction.
[0025]
In this way, the through hole 39, 43a, 43b, the hydraulic plunger 71, the lock pin 72, the return spring 73, and the like constitute a lock mechanism that allows the center tappet 31 and the side tappet 32 to be coupled to and detached from each other. Yes.
[0026]
In this locking mechanism, when the hydraulic pressure is applied, the hydraulic plunger 71 moves to the lock pin 72 side and the end portion enters the through hole 39 on the center tappet 31 side, and the lock pin 72 resists the return spring 73. The end of the lock pin 72 is moved into the through hole 43 a of the other side (back side) side tappet body 32 a of the side tappet 32. At this time, the hydraulic plunger 71 straddles the divided portion of the center tappet 31 and the one side (front side) side tappet body 32b of the side tappet 32, and the lock pin 72 is the other of the center tappet 31 and the side tappet 32. It straddles the divided portion with the side tappet body 32a, and they cooperate to couple the center tappet 31 and the side tappet 32 into a locked state. When the hydraulic pressure is released, the return spring 73 pushes the lock pin 72 back toward the hydraulic plunger 71, the hydraulic plunger 71 returns to the original position, and both end surfaces of the lock pin 72 are the through holes 39 of the center tappet 31. The center tappet 31 is detached from the side tappet 32 and is unlocked (unlocked).
[0027]
As described above, the lock mechanism can be switched between a locked state and an unlocked state by hydraulic pressure. In the locked state, the side tappet 32 and the center tappet 31 are coupled, and the center tappet driven by the side tappet 32 and the center cam 21 is used. 31 cooperates to lift the valve in a high speed manner. In the unlocked state, the center tappet 31 is detached from the side tappet 32 and freely moves while being pressed against the center cam 21 by the lost motion springs 35a and 35b, and the side tappet 32 drives the side tappets 22 and 23. Then, the valve is lifted in a low-speed manner or is substantially deactivated.
[0028]
The side tappet 32 has boss portions 81a and 81b formed around the through holes 43a and 43b inside the top portions (cam contact portions) of the side tappet bodies 32a and 32b. Continuous ribs 82 are formed that extend downward in the axial direction and tappet axial direction of the boss portions 81a, 81b continuously to the left and right boss portions 81a, 81b of the 32b, and are connected to the left and right below the connecting portion 32c. A skeleton structure having no meat is formed around the boss portions 81a and 81b and around the rib 82.
[0029]
Further, as described above, the tappet 3 is cut out around the through hole 43a on the outer peripheral surface 41a of the side tappet body 32a on which the bush 77 for inserting the pin 86 is inserted and fixed (rear side). A rotation stop member 87 is attached to the portion. The rotation stopping member 87 has a substantially rectangular plate shape, and one end of the pin 86 is inserted and fixed from a substantially vertical direction at a position eccentric to one side in the longitudinal direction.
[0030]
Then, as shown in FIG. 2, the tappet slide is arranged so that the inner periphery of the tappet guide hole 4 can be moved only in the tappet sliding direction by engaging a rotation stop member 87 held on the tappet 3 side. A groove 88 extending in the direction is provided. The rotation stop member 87 is attached in such a posture that the upper end becomes longer upward with respect to the lock receiving pin 86 so as to approach the cam contact surface. The rotation of the tappet 4 is restricted in cooperation with the groove 88 on the inner periphery of the tappet guide hole 4.
[0031]
The hydraulic pressure for operating the hydraulic plunger 71 of the lock mechanism is supplied from an oil pump (hydraulic power source) and controlled by a hydraulic control valve (not shown). It is supplied to the working hydraulic chamber behind the plunger 71. Therefore, as shown in FIG. 1, an oil gallery 91 is provided on the cam carrier 1, and the oil gallery 91 branches from the oil gallery 91 so as to supply the oil pressure from the oil gallery 91 to the lock mechanism of the tappet 3. A hydraulic oil supply passage 93 that opens to the peripheral surface is provided, and the inner periphery of the tappet guide hole 4 of the hydraulic oil supply passage 93 is in a state where the side cam sliding contact surface of the side tappet 32 is in contact with the base circle portion of the side cams 22 and 23. An oil path 94 to the working hydraulic chamber is formed in one side tappet body 32b of the side tappet 32 so as to communicate with the opening in the surface.
[0032]
The hydraulic pressure from the oil pump (hydraulic power source) is controlled by a hydraulic control valve and guided to the oil gallery 91, the side cam sliding contact surface of the side tappet 32 comes into contact with the base circle portion of the side cams 22 and 23, and the hydraulic oil supply passage When the opening in the inner peripheral surface of the tappet guide hole 4 communicates with the oil passage 94 on the tappet side, it is introduced into the oil passage 94 on the tappet 3 side via the hydraulic oil supply passage 93 and the hydraulic pressure on the back of the hydraulic plunger 71 Supplied to the chamber.
[0033]
As described above, the valve operating apparatus for the engine of this embodiment is provided with the projecting portions 38a, 38b, 38c, 38d of the center tappet 31 on the side tappet bodies 32a, 32b of the side tappet 32. From the upper side (counter valve side) to the lower end of the lost motion spring seat parts 34a, 34b, a predetermined distance is formed between the protruding parts 38a, 38b, 38c, 38d of the center tappet 31. By forming the notch-shaped relief portions 85a, 85b, 85c, and 85d, when the tappet 32 is tilted during driving, it can escape to the valve side end of the side tappet 32, and the valve side end outer edge of the side tappet 32 And an increase in surface pressure between the inner surface of the tappet guide hole 4 is prevented. Further, since the side end portion of the side tappet 32 does not contact the center tappet 31, the lower end of the center tappet 31 is not pushed by the side tappet 32, and the center tappet 31 is bent so that the lower end of the center tappet 31 and the tappet guide An increase in surface pressure with the inner surface of the hole 4 is prevented. Therefore, it is possible to prevent uneven wear due to the fall of the tappet 3 during driving. Further, since the relief parts 85a, 85b, 85c, 85d are formed from the upper side (counter valve side) to the lower end of the side tappet 32 from the lost motion spring seat parts 34a, 34b, the sliding contact parts 42a, 42b, 42c, 42d are The lost motion spring seat portions 34a and 34b do not obstruct the cutting of the sliding surface before the relief portion, and the processing is easy, and the lost motion spring seat portion is not scraped at the time of cutting.
[0034]
In addition, as described above, the side tappet 32 is formed with ribs 82 that extend downward continuously from the left and right boss portions 81a and 81b of both side tappet bodies 32a and 32b and connect the left and right below the connecting portion 32c. Since the skeleton structure has no meat around the boss portions 81a and 81b and around the rib 82, it is lightweight, has high rigidity, and has continuous ribs 82, so that the hot water flow during casting is improved. Are better.
[0035]
In the above-described embodiment, the engine in which the cam carrier is separated and the cam carrier is assembled to the upper part of the cylinder head has been described. However, the present invention is also applied to an engine having an integrally structured cylinder head in which the cam carrier is not separated. Of course, can be applied.
[0036]
【The invention's effect】
As is apparent from the above description, the valve operating apparatus for an engine according to the present invention includes a center tappet and side tappets on both sides in the cam shaft direction, and the side tappet and the center tappet are in a sliding contact surface parallel to the cam shaft direction. In a valve operating apparatus using a tappet that abuts in a direction orthogonal to the camshaft, a predetermined distance between the center tappet protrusion at a portion facing the protrusion of the center tappet at the valve side end of the side tappet. By forming a notch-shaped relief part to form an interval, it is possible to prevent an increase in surface pressure between the outer edge of the valve side end of the side tappet and the inner surface of the tappet guide hole when the tappet is tilted. And the inner surface of the tappet guide hole can be prevented from increasing, and uneven wear of the inner surface of the tappet guide hole can be prevented.
[0037]
In addition, the two lost motion springs are distributed to both sides in the direction perpendicular to the cam shaft, and in particular, the lost motion spring seat part is cammed across the plane connecting the sliding contact surfaces of both side tappets in the cam axis direction in plan view. In the case of a tappet that protrudes in a direction perpendicular to the axis, by forming a relief at the valve end of the side tappet, the sliding surface of the side tappet does not interfere with the lost motion spring seat in side view. Therefore, it is not necessary to avoid the lost motion spring seat portion for cutting the sliding surface of the side tappet, and the processing becomes easy.
[Brief description of the drawings]
FIG. 1 is a front view showing a cross section perpendicular to a camshaft of a main part of a valve operating apparatus according to an embodiment of the present invention.
FIG. 2 is a side view showing a cross section parallel to a camshaft of a main part of the valve operating apparatus according to the embodiment of the present invention.
FIG. 3 is a plan view of the tappet of the valve gear according to the embodiment of the present invention.
FIG. 4 is a longitudinal sectional view in front view showing a central cross section perpendicular to the camshaft of the tappet of the valve gear of the embodiment of the present invention.
FIG. 5 is a bottom view of the tappet of the valve gear according to the embodiment of the present invention.
FIG. 6 is a longitudinal sectional view in side view showing a central cross section parallel to the camshaft of the tappet of the valve gear of the embodiment of the present invention.
FIG. 7 is a cross-sectional view in plan view passing through the center of the tappet locking mechanism of the valve gear according to the embodiment of the present invention.
FIG. 8 is a longitudinal sectional view in side view showing a central cross section parallel to the cam shaft of a single side tappet of the tappet of the valve operating apparatus according to the embodiment of the present invention.
FIG. 9 is a plan view of a single side tappet of the tappet of the valve gear according to the embodiment of the present invention.
FIG. 10 is a front view of a single side tappet of the tappet of the valve gear according to the embodiment of the present invention.
FIG. 11 is a bottom view of a single side tappet of the tappet of the valve gear according to the embodiment of the present invention.
FIG. 12 is a plan view of a center tappet alone of the tappet of the valve gear according to the embodiment of the present invention.
FIG. 13 is a front view of a center tappet alone of the tappet of the valve gear according to the embodiment of the present invention.
[Explanation of symbols]
2 Camshaft 3 Tappet 4 Tappet guide hole 5 Valve 21 Center cam 22, 23 Side cam 31 Center tappet 32 Side tappet 32a, 32b Side tappet body 32c Connecting portion 34a, 34b Spring seat portion 35a, 35b Lost motion spring 36a, 36b End face 38a, 38b, 38c, 38d Protruding portions 40a, 40b Inner end surfaces 41a, 41b Outer peripheral surfaces 42a, 42b, 42c, 42d Sliding contact portions 82 Ribs 85a, 85b, 85c, 85d Escape portions

Claims (1)

The tappet that contacts the cam and slides in the tappet guide hole to drive the valve is composed of a center tappet located in the center of the cam shaft direction and side tappets located on both sides of the cam shaft direction. Sliding contact surfaces extending in the tappet shaft direction parallel to the cam shaft direction are formed at both ends in the direction orthogonal to the cam shaft, and the center tappet faces the side tappets on both sides at both ends in the direction orthogonal to the cam shaft. Formed in a substantially I shape in plan view having a protruding portion that protrudes and extends in the tappet axis direction, the inner side surface of each protruding portion that faces the direction orthogonal to the cam axis is parallel to the cam shaft and in the tappet axis direction. A sliding contact surface that extends and comes into contact with the sliding contact surface of the side tappet. The center tappet and the side tappet can be moved relative to each other in the tappet sliding direction, and the locking mechanism The cam is divided into a center cam corresponding to the center tappet and a pair of side cams corresponding to the side portions of the side tappet, and a cam profile is formed by the center cam and the pair of side cams. A valve operating device for an engine, wherein the operating characteristics of the valve can be changed by coupling or disengaging operation of the locking mechanism,
An outer peripheral surface of the tappet constituted by the center tappet and the side tappets on both sides is substantially cylindrical, and the side tappets on both sides extend substantially perpendicular to both side tappets in the vicinity of the valve side end portions. The connecting portion has a contact portion with the valve stem on the surface on the side opposite to the cam, and a lost motion spring seat portion is formed on both sides in a direction perpendicular to the cam shaft of the connecting portion, Two lost motion springs are disposed between each lost motion spring seat portion and the back surface of the cam sliding contact portion of the center tappet to press the center tappet against the center cam when the lock mechanism is released.
The lost motion spring seat portion is formed so as to protrude in a direction perpendicular to the cam shaft over a surface connecting the sliding contact surfaces of both side tappets in the cam shaft direction in plan view.
A portion of the side tappet facing the protrusion of the center tappet on the valve side end is predetermined between the lost motion spring seat portion and the valve end of the center tappet. valve operating system for an engine, wherein a notch-shaped relief portion is formed so as to form a spacing.

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