JP2003201809A - Valve system of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure sliding length against a cam of a tappet and to reduce biased abrasion between the tappet and a tappet guide. <P>SOLUTION: The cylindrical tappet 13 is divided into a center tappet 44 which is long in the cam sliding direction and roughly rectangular of plane view seen on and side tappets 45, 45 positioned on its both sides, and extended parts 44d...44d are provided extending to the both sides so as to accumulated on outer peripheral surfaces 45c, 45c of the side tappets 45, 45 on the both sides of outer peripheral surfaces 44c, 44c in the cam sliding direction on the center tappet 44. Additionally, a pair of springs 46, 46 to energize the center tappet 44 to the cam side is arranged on both sides of a locking mechanical constituted of a plunger 47 to engage and release the center tappet and the side tappets 45, 45 with and from each other, a locking pin 48, locking holes 44h, 45h, 45h, etc. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve operating system for an engine of a type in which a valve is directly driven via a tappet and belongs to the technical field of an internal combustion engine of a vehicle.

[0002]

2. Description of the Related Art As a valve operating device for opening and closing an intake valve and an exhaust valve provided in a cylinder of an engine, there is a type in which the valve is directly driven by a cam provided on a cam shaft. There is one that uses a tappet that constantly contacts the cam to convert the rotation of the cam into reciprocating motion and transmit this to the valve.

In order to improve fuel economy and output, it is desired to optimize the valve opening state such as opening / closing timing and lift amount according to the operating conditions.
-508205 and German published patent DE 1960
Some are disclosed in 2013A1. These valve operating devices have a center tappet and a side tappet arranged concentrically. For example, the device described in JP-A-5-508205 mentioned above connects these tappets by a locking mechanism. In addition, the valve is lifted by a high speed cam, or the center tappet and the side tappet are separated and the center tappet is used by a low speed cam to lift the valve.

However, in the above valve operating device, since the center tappet having a circular shape in plan view is surrounded by the concentric side tappets, the sliding length of the cam and thus the lift amount cannot be increased. is there.

To solve this problem, for example,
There is a valve operating device disclosed in Japanese Patent Laid-Open No. 7-71213.
As shown in FIG. 11, in this valve operating device, the tappet X is divided into a center tappet X1 and side tappets X2 and X2 located on both sides of the center tappet X1 along the cam sliding direction indicated by the arrow. By dividing and accommodating these into the cylindrical tappet guide Y, the sliding length of the cam can be increased, and as a result, the lift amount can be increased.

[0006]

By the way, the above valve operating system still has the following problems.
That is, when the side tappets X2, X2 are driven by the low speed cam, the edge portions X2 ', X2' of the arcuate outer peripheral surfaces of the side tappets X2, X2 come into sliding contact with the inner peripheral surface Y'of the tappet guide Y. Become. In that case, since the center tappet X1 does not receive the driving force of the cam, the surface pressure between the side tappets X2, X2 and the inner peripheral surface Y ′ of the tappet guide Y increases, and the tappet X and the tappet guide Y are separated from each other. There is a problem in terms of wear resistance because uneven wear occurs between them.

In view of the above problems in the valve operating system of the engine of the type in which the valve is directly driven via the tappet, the present invention secures the sliding length of the tappet with respect to the cam, and then the tappet and the tappet guide. An object is to reduce uneven wear between the two.

[0008]

In order to solve the above problems, the present invention is characterized by having the following configuration.

First, the invention according to claim 1 is a cam having a cylindrical tappet slidably accommodated in a guide hole provided in a cylinder head, and a cam for driving a valve via the tappet. The tappet having a shaft is divided into a substantially rectangular center tappet that is long in the sliding direction of the cam in plan view and side tappets located on both sides of the tappet, and the center tappet and the side tappet are The present invention relates to a valve operating system for an engine, which is provided with a lock mechanism for engaging and disengaging with each other, and the cam shaft is provided with a plurality of cams having different profiles corresponding to a center tappet and a side tappet for each tappet. The center tappet overlaps with the outer peripheral surface of the side tappet at least on both sides of the outer peripheral surface on the downstream side in the sliding direction of the cam. The lock mechanism is provided in the direction of the cam shaft across the center tappet and the side tappet, and a pair of springs for urging the center tappet toward the cam are provided on both sides thereof. Is provided.

According to the present invention, the center tappet is provided with the extending portions extending on both sides so as to overlap with the outer circumferential surface of the side tappet on both sides of the outer circumferential surface on the downstream side in the sliding direction of the cam. When the sliding length of the cam is secured and the side tappet is driven by the cam corresponding to the side tappet, the force for pressing the side tappet against the guide hole (for example, guide tappet) is applied to the center through the extension portion. Since it is dispersed on the tappet side, uneven wear between the tappet and the guide hole as in the conventional case can be reduced and the wear resistance can be improved. The cam includes a cam having a perfect circular profile and a lift amount of zero.

Further, since a pair of springs for urging the center tappet toward the cam side are provided on both sides of the lock mechanism, the relative movement amount of the center tappet with respect to the side tappet in the unlocked state of the lock mechanism, and thus in the locked state. The valve lift can be increased. That is, even if the lift amount of one cam is substantially zero, the lift amount of the other cam can be increased. Further, since the pair of springs is provided, the vertical movement of the center tappet incorporated in the side tappet becomes smoother as compared with the case where there is one spring.

Next, the invention according to claim 2 is the engine valve operating system according to claim 1, wherein the side tappets on both sides are connected by a cylindrical skirt portion which is in sliding contact with the guide hole on the valve side. In addition, a valve stem abutting portion with which the valve stem abuts and a seat portion for receiving the valve-side end portions of the pair of springs are provided therein, and the two lower portions provided on the cam shaft are provided. The lift amount cam corresponds to both side tappets, and the high lift amount cam located between these low lift amount cams corresponds to the center tappet.

According to the present invention, the constitution of the side tappet in the above-mentioned claim 1 can be further embodied,
In the unlocked state of the lock mechanism, the center tappet can move more stably relative to the side tappet, and the side tappet, that is, the tappet can surely open and close the valve via the valve stem. For example, when both side tappets are driven by a low lift cam in the unlocked state, a low lift is provided while
When the center tappet is driven by the high lift cam in the locked state, a high lift amount is provided.

According to a third aspect of the present invention, in the engine valve operating device according to the first or second aspect, the lock mechanism is provided in the center tappet and the side tappet in the camshaft direction. An extending lock hole,
The tappet has a lock pin and a plunger slidable in the lock holes in a predetermined positional relationship between the tappets, and the lock hole in the center tappet is a protrusion provided on the back side of the top surface of the tappet. The cam-side ends of the pair of springs on both sides of the lock mechanism are disposed so as to pass through the portion so as to overlap with the projecting portion in a side view.

According to the present invention, the structure of the lock mechanism according to claim 1 or 2 can be further embodied, and the center tappet and the side tappet can be separated by the lock mechanism having a relatively simplified structure. It can be disengaged.

Further, since the end portions of the pair of springs are arranged so as to overlap the projecting portion provided on the center tappet in a side view, the length of the springs can be secured long. The degree of freedom in designing the spring is increased.

According to a fourth aspect of the invention, in the engine valve operating system according to the third aspect, the lock pin is in the lock hole of the center tappet and the plunger is one side when the lock mechanism is in the unlocked state. And a spring for urging the lock pin toward the plunger side is provided.

According to the present invention, since the lock pin is constantly urged toward the plunger by the spring, the lock pin is reliably arranged in the home position, that is, in the lock hole of the center tappet in the unlocked state. That is,
With this lock mechanism, engagement and disengagement of the center tappet and the side tappet can be made more reliable.

According to a fifth aspect of the present invention, in the engine valve operating system according to the fourth aspect, the lock pin received in the lock hole of the other side tappet is received. A member is provided, and the receiving member holds a detent member that engages with a guide groove provided in the inner peripheral surface of the guide hole of the cylinder head in the tappet sliding direction to prevent rotation of the tappet. It is characterized by being

According to the present invention, when the lock pin advances toward the lock hole side of the other side tappet, the receiving member in the lock hole accommodates the lock pin into which the center tappet and the other side tappet are accommodated. Engagement with is more reliably realized.

Further, due to the engagement between the detent member on the tappet side and the guide groove on the guide hole side, the tappet does not rotate around the axis in the guide hole, and a good sliding position between the tappet and the cam is obtained. Relationship is maintained. Moreover, since the detent member is held by the receiving member, there is an advantage that the detent can be achieved without unnecessarily increasing the number of parts.

According to a sixth aspect of the present invention, in the engine valve operating device according to any of the third to fifth aspects, a gap is provided between the facing surfaces of the center tappet and both side tappets. Is provided, and the sleeves are fitted in the lock holes of both side tappets,
The end portions on the side of the center tappet project into the gaps, respectively, and the center tappet is provided with a contact surface that abuts on the protrusions of these sleeves from the valve side.

The center tappet is constantly urged toward the cam side, that is, upward by a pair of springs. According to the present invention, when the protrusion of the sleeve and the contact surface provided on the center tappet contact each other. The upward movement of the center tappet is regulated, and the center tappet is prevented from coming out of the side tappet.

According to a seventh aspect of the present invention, in the engine valve operating device according to any of the first to sixth aspects, the cam slide around the cam side opening of the guide hole in the cylinder head. An oil receiving recess for supplying lubricating oil to the sliding surface between the guide hole and the tappet is provided at a portion along the direction.

According to the present invention, the lubricating oil can be satisfactorily supplied to the sliding surface between the guide hole and the tappet and the lubricating oil can be efficiently collected by the simplified structure.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a valve operating system for an engine according to an embodiment of the present invention will be described.

[Schematic Configuration of Engine] As shown in FIGS. 1 and 2, the engine includes four cylinders A1 to A4 and a cylinder block 1, a cylinder head 2, and a head cover 3. And one cylinder A1 to A4
The two intake ports Pin1, Pin2 and the intake valves 11, 11 and the two exhaust ports Pex1, Pe
It is a four-valve 16-valve engine in which x2 and exhaust valves 12 and 12 are provided, and four tappets 13 ... 13 (only two are shown in FIG. 1) are provided for each of the cylinders A1 to A4.

Further, in this engine, for each tappet 13, three cams 16, 1 formed on the intake and exhaust camshafts 14, 15 having different profiles are provided.
This is a variable valve type engine in which 6 and 17 (two cams 16 and 17 are shown in FIG. 1) are arranged. In addition, in FIG.
The code "13in1" of the tappet 13 is the tappet 1 corresponding to one intake port Pin1 or one intake valve 11.
3, the reference numeral "13in2" indicates the tappet 13 corresponding to the other intake port Pin2, that is, the other intake valve 11. Similarly, the code "13
“Ex1” indicates the tappet 13 corresponding to one exhaust port Pex1, that is, the one exhaust valve 12, and the reference numeral “13ex2” indicates the tappet 13 corresponding to the other exhaust port Pex2, that is, the other exhaust valve 12. Indicates that.

[Cylinder Head] The cylinder head 2 has a cylinder head base portion 20 and side wall portions 21, 22, and 23 provided upright from the base portion 20. Further, the cylinder head base portion 20 has an intake port Pi that faces the combustion chambers B ... B.
n1 ... Pin1, Pin2 ... Pin2 and exhaust port P
Ex1 ... Pex1, Pex2 ... Pex2, etc. are formed, and fuel injection valves (not shown), intake and exhaust manifolds 24, 25, etc. are assembled. And, this cylinder head 2 has a cylinder head base 2
It is attached to the cylinder block 1 by head bolts 26 ... 26 that penetrate 0 and project into the cylinder block 1.

The cylinder head 2 is provided with a support member 30. The support member 30 supports the intake and exhaust camshafts 14 and 15, and a tappet guide 31 that slidably accommodates the tappets 13 ...
... has 31.

Ribs 32 and 33 extending forward and backward are formed on the support member 30. Then, first to third main oil passages 34 to 36 for supplying the working oil pressure to the tappets 13 ... 13 are formed in the ribs 32 and 33 in parallel with the intake and exhaust camshafts 14 and 15.

[Cam] Three cams with different profiles 1
Low lift amount cams 16 and 1 at both ends of 6, 16 and 17
6 has the same profile, and the high lift amount cam 17 at the center has a different profile from the cams 16 and 16. That is, the low lift amount cams 1 at both ends
6 and 16 show a small lift amount and a high lift amount cam 1 in the center.
7 provides a large lift amount.

It should be noted that, for example, instead of the low lift amount cam 16, an extremely low lift amount cam 18 (providing a lift amount of about 1 to 2 mm) having a substantially circular profile shown by a chain line in FIG. 1 can be used. . This is because when the fuel injection valve is provided in the intake ports Pin1 and Pin2 and port injection is executed, if the low lift amount cam 16 having a perfect circular profile is used, the valve is completely stopped. Then,
When fuel is accumulated in the intake ports Pin1 and Pin2 and then switched to the high lift amount cam 17, this fuel is sucked into the combustion chamber B all at once. In order to avoid such a problem, the extremely low lift amount cam 18 is used. Therefore, in the direct injection engine, it is possible to use a cam whose profile is a perfect circle and which has a substantial lift amount of zero, so that the valve is completely stopped.

[Tappet] The stem end 41 of the intake valve 11 or the exhaust valve 12 is in contact with the lower portion of the substantially cylindrical tappet 13, which is a characteristic part of the present invention. The stem end 41 is provided with a spring receiver 43 that receives a valve spring 42 interposed between the stem end 41 and the cylinder head base portion 20. The valve spring 42 connects the intake valve 11 or the exhaust valve 12 to the intake port Pin2.
Alternatively, the exhaust port Pex2 is biased in the closing direction.

As shown in FIG. 3, the tappet 13 includes a center tappet 44 having a flat surface 44a that abuts the high lift amount cam 17 and has a long side in the sliding direction of the cam 17 as shown by the arrow a. , The planes 45a, 45a contacting the low lift amount cams 16, 16 are also indicated by the arrow a.
The side tappets 45 and 45, which are configured to have long sides in the sliding direction, are positioned so as to sandwich the center tappet 44 therebetween.

In the following, as one example, one intake port Pi
The configuration of the tappet 13 corresponding to n2 will be described in detail.

<Center Tappet> As shown in FIGS. 4, 6 and 7, the center tappet 44 has a high lift amount cam 1
A substantially rectangular flat surface 44a that abuts 7 is formed along the sliding direction of the cam 17 indicated by the arrow a. Further, the center tappet 44 has two outer surfaces 44b, 44b extending downward from an edge of the flat surface 44a along the cam sliding direction.
And two arcuate outer peripheral surfaces 44c, 44c extending downward from both ends of the plane 44a in the cam sliding direction.

The outer peripheral surface 44 of the center tappet 44
44d are formed on both sides of the c and 44c, and extended portions 44d ... 44d extending in the direction of the site tappet 45, 45 are formed on the extended portions 44d ... 44d.
The receiving surfaces 44e ... 44e that are in sliding contact with 45 are formed. 44d, that is, the receiving surfaces 44e ...
44f are provided at the base end of 44e.

On the back side of the flat surface 44a of the center tappet 44, there is formed a protruding portion 44g extending downward so as to be orthogonal to the cam sliding direction, that is, parallel to the intake camshaft 15, and the protruding portion 44g. The lock hole 44h is formed so as to penetrate therethrough. A pair of spring seat portions 44i, 44i (only one is shown in FIG. 6) are formed on the back side of the flat surface 44a so as to sandwich the projecting portion 44g.

<Side Tappet> As shown in FIGS. 5 to 7, the side tappet 45 has a low lift amount cam 1.
Two planes 45a, 45a that abut against Nos. 6, 16 are formed along the sliding direction of the cams 16, 16 shown by the arrow a. In addition, the side tappet 45, 45 has a flat surface 4
Two inner side surfaces 45b and 45b extending downward from edges of the cams 5a and 45a along the cam sliding direction, and flat surfaces 45a and 45a.
Two substantially arc-shaped outer peripheral surfaces 45c, 45c extending downward from both end portions of a in the intake camshaft 15 direction are formed.

A connecting portion 45d is formed which connects both side tappets 45, 45 at the lower position and provides a contact portion with the stem end 41. This connecting part 4
A pair of pulling seats 45e, 45e are formed near both ends along the cam sliding direction of 5d.

Further, on the side tappets 45, 45, projecting portions 45f ... 45f extending from both ends of the inner side surfaces 45b, 45b in the cam sliding direction toward the center tappet 44 are formed in a non-contact state with the center tappet 44. ing. The projections 45f ... 45f are provided so as to correspond to the recesses 44f ... 44f of the center tappet 44.

The side tappets 45, 45 extend downward from both ends of the planes 45a, 45a in the cam sliding direction, that is, the protrusions 45f ... 45f, and are in sliding contact with the receiving surfaces 44e ... 44e of the center tappet 44. Sliding surface 45g ...
45 g is formed.

The side tappets 45, 45 pass through the axial center of the tappet 13 so as to penetrate from one outer peripheral surface 45c to the other outer peripheral surface 45c.
Lock holes 45h, 45h parallel to the direction are formed. These lock holes 45h and 45h are configured to communicate with the lock hole 44h of the center tappet 44 in a straight line when the flat surface 44a of the center tappet 44 and the flat surfaces 45a and 45a of the side tappets 45 and 45 are flush with each other. Has been formed.

45e on the side of the side tappets 45, 45 and the center tappet 4
Between the pair of spring seat portions 44i, 44i on the fourth side,
A pair of springs 46, 46 for urging the center tappet 44 toward the high lift amount cam 17 side are interposed. In that case, the upper ends of the springs 46, 46 are arranged so as to overlap the protrusion 44g provided on the center tappet 44 in a side view.

By doing so, the center tappet 44
Is installed between both side tappets 45, 45, and the outer peripheral surfaces 44c, 44c, 45c, 45c and the tappet guide 31
44e are slidable, and the receiving surfaces 44e ... 44e of the center tappet 44 and the sliding contact surfaces 45f ... 45f of the side tappets 45, 45 are slidable. The center tappet 44 is mounted on the side tappets 45, 45 with the springs 46, 46 interposed therebetween. The side tappets 45, 45 resist the biasing force of the springs 46, 46.
It becomes possible to move relative to.

<Lock mechanism> Side tappet 45, 45
Center tappet 4 built to move relative to
4 and the side tappets 45, 45 connected to the stem end 41 of the intake valve 11 will be described with reference to FIGS.

As described above, the lock hole 44h of the center tappet 44 and the lock hole 4 of the side tappets 45, 45 are provided.
5h and 45h are in straight line communication with the intake camshaft 15 when the flat surface 44a of the center tappet 44 and the flat surfaces 45a and 45a of the side tappets 45, 45 are flush with each other.

Lock hole 45 of one side tappet 45
At h, the lock hole 44 of the center tappet 44 is hydraulically operated.
In the lock hole 44h of the center tappet 44, the plunger 47 advancing to h is pushed by the plunger 47 and advancing into the lock hole 45h of the other side tappet 45, and around the lock pin 48. Each of the springs 49 is provided with a spring 49 for constantly urging the lock pin 48 toward the plunger 47 via a flange portion 48a provided at a portion of the lock pin 48 near the plunger 47.

Further, the lock hole 44 of the center tappet 44
In h, bushes 50, 5 are provided near both ends of the lock pin 48.
1 is inserted and fixed. Of the bushes 50 and 51, the bush 50 on the plunger 47 side is the lock pin 48.
Of the plunger 4 that abuts the flange portion 48a of the lock pin 48 and exceeds the outer surface 44b of the center tappet 44 of the lock pin 48.
Restrict movement to side 7. The other bush 51 compresses and holds the spring 49 between itself and the flange portion 48a.

Further, separate bushes 52 and 53 are inserted and fixed in the lock holes 45h and 45h of the side tappets 45 and 45, respectively. Of the bushes 52, 53, the bush 52 on the plunger 47 side is configured to be open so as to face the lock pin 48, and the plunger 4 is provided inward.
7 is slidably fitted. The other bush 53 accommodates the tip end portion of the lock pin 48 which is projected, and the stopper portion 53a which restricts the protrusion of the lock pin 48 beyond a predetermined length.
have.

The end portions 52a, 53b of the bushes 52, 53 on the side of the center tappet 44 are formed on the outer side surfaces 44b, 44b of the center tappet 44 and the side tappets 45, 4 respectively.
5 are arranged so as to protrude by a predetermined length into the gaps G, G between the inner side surfaces 45b, 45b.

<Rotating Mechanism for Tappet> FIGS. 6 and 7
As shown in FIG.
Ball support portion 53 provided on the outer peripheral side of the tappet 13 of No. 3
A ball member 54 is supported by c so as to partially project. On the other hand, the sliding surface of the tappet guide 31 with the tappet 13 has a guide groove 31 along the sliding direction of the tappet 13.
a is formed to be engageable with the ball member 54.

By doing so, the rotation of the tappet 13 around the axis in the tappet guide 31 is restricted through the engagement between the ball member 54 and the guide groove 31a. As a result, the tappet 13, that is, the center tappet 44, the side tappets 45 and 45, and the cams 16 and 1
A good sliding positional relationship with Nos. 6 and 17 is maintained.

<Mechanism for Preventing Tappet from Pulling Up> As described above, the lock holes 45h of the side tappets 45, 45,
The ends 52a, 53b of the bushes 52, 53 fixed to 45h on the side of the center tappet 44 are the center tappet 44.
It is arranged so as to project to the side by a predetermined length. On the other hand, as shown in FIGS. 4, 6 and 7, the center tappet 4
No. 4, outer side surfaces 44b, 44b have lock holes 44h, 44
Abutment surface 44 that is a circular arc-shaped peripheral surface that is concave downward around h
Abutting portions 44j, 44j having j ', 44j' are provided so as to project by a predetermined length in the direction of both side tappets 45, 45.

The center tappet 44 has a spring 46,
Although the upward biasing force of 46 always acts, the contact surfaces 44j ', 44j' on the side of the center tappet 44 and the side tappets 45, 4 are configured by the above-mentioned configuration.
The center tappet 4 from the tappet 13 when the end portions 52a and 53b of the bushes 52 and 53 on the fifth side contact and engage with each other.
The upward movement of 4 is restricted. Since the above-mentioned configuration does not restrict the downward movement of the center tappet 44 with respect to the side tappets 45, 45, in the unlocked state, the center tappet 44 has the spring 4
It can move downward against the biasing force of 6,46.

[Oil receiving recess for tappet lubrication] As shown in FIGS. 1 and 3, the cams 16 and 1 of the tappet guide 31 are shown.
At the part along the cam sliding direction around the opening on the 6 and 17 side,
The oil receiving recess 31 that supplies lubricating oil to the sliding surfaces of the tappet guide 31, the tappet 13 and the tappet guide 31, the center tappet 44, and the side tappets 45, 45.
b, 31b, 31c ... 31c are provided. These oil receiving recesses 31b, 31b, 31c ... 31c are provided so as to be inclined downward on the tappet 13 side.

By doing so, the lubricating oil can be satisfactorily supplied to the sliding surface between the tappet guide 31 and the tappet 13 and the lubricating oil can be efficiently collected by the simplified structure.

[Supply of Operating Hydraulic Pressure to Tappet] The supply of operating hydraulic pressure to each tappet 13 ... 13 will be described.

In the configuration shown in FIG. 2, when the first hydraulic control valve (OCV1) 61 is on, the oil passage 6
While the working oil pressure is supplied from 2 to the first main oil passage 34 (see FIG. 1), the working oil pressure is released from the first main oil passage 34 when it is off.

In the first main oil passage 34, the tappet 13 ...
34a extending in 13 directions are provided in the cylinders A1 to 34a.
The same number as A4 is formed. These branch oil passages 34a ...
34a is one intake port Pin of each cylinder A1-A4
1 ... Communicating with the tappet guides 31 ... 31 corresponding to Pin1 to supply the working hydraulic pressure to the tappets 13in1 ... 13in1. That is, by turning on the first hydraulic control valve 61, one of the intake ports Pin1 ...
The lift amount of the in1 intake valves 11 ... 11 is increased.

On the other hand, the second hydraulic control valve (OC
When V2) 63 is on, operating oil pressure is supplied to the second and third main oil passages 35 and 36 (see FIG. 1) from another oil passage 64, while when off, the second and third main oil passages are supplied. Road 3
The hydraulic pressure is released from 5, 36.

In the second main oil passage 35, the tappet 13 ...
The branched oil passages 35a ... 35a extending in 13 directions are cylinders A1 to A1.
The same number as A4 is formed. These branch oil passages 35a ...
35a is the other intake port Pin of each cylinder A1 to A4
2 ... Communicating with the tappet guides 31 ... 31 corresponding to Pin2, the working oil pressure is supplied to the tappets 13in2 ... 13in2. Further, the tappet 1 is provided in the third main oil passage 36.
The branch oil passages 36a ... 36a extending in the 3 ... 13 directions are connected to the exhaust ports Pex1 ... Pex1, Pe of the cylinders A1 to A4.
x2 ... Communicating with the tappet guides 31 ... 31 corresponding to Pex2, the working hydraulic pressure is tappets 13ex1 ... 13ex
1, 13ex2 ... 13ex2 are simultaneously supplied. That is, when the second hydraulic control valve 63 is turned on, the lift amount of the intake valves 11 ... 11 of the other intake ports Pin2 ... Pin2 increases and the exhaust valves 1 of both the exhaust ports Pex1 ... Pex1, Pex2 ... Pex2.
The lift amount of 2 ... 12 becomes large.

Then, as shown in FIG. 7, the tappet 13
In the vicinity of the lock hole 45h of the side tappet 45 on the side of the plunger 47, the oil passages 34a, 65 for supplying the hydraulic pressure for operating the lock mechanism, that is, the plunger 47,
66 is provided. The oil passage 65 is the side tappet 4
5, which communicates with a branched oil passage 34a vertically formed from the outer periphery of the side oil passage 65 toward the oil passage 65, and extends from the side of the side tappet 45 opposite to the cam side and extends in the sliding direction of the tappet 13. Further, the oil passage 66 is bored from the lock hole 45h of the side tappet 45 toward the oil passage 65, as shown in FIGS.
As shown in FIG.
The space 52c behind the plunger 47 in the bush 52 and the oil passage 65 are communicated with each other via the.

Next, as an example, one intake port Pi
n1 ... Tappet 13in1 ... 13i corresponding to Pin1
n1 has two extremely low lift amount cams 18, 18, one low lift amount cam 16, and the other intake port Pin2 ... Pin2
Corresponding to the tappet 13in2 ... 13in2, two low lift amount cams 16 and 16 and one high lift amount cam 17,
Then, both exhaust ports Pex1 ... Pex1, Pex2 ...
Tappets 13ex1 ... 13ex1, corresponding to Pex2
13ex2 ... 13ex2 each having two low lift amount cams 16 and 16 and one high lift amount cam 17, each intake valve 11 at the time of on / off operation of both hydraulic control valves 61 and 63. 11 and exhaust valve 12 ... 1
The lift amount of 2 is shown in FIG.

That is, both hydraulic control valves (O
When both CV1, OCV2) 61 and 63 are turned off, the lift amount corresponding to one intake port Pin1 becomes an extremely low lift amount, and the valve is substantially stopped, so that the air can be discharged from the combustion chamber B by only one valve. ... will be introduced to B.

Next, the first hydraulic control valve 61
When is switched from OFF to ON, the lift amount corresponding to one of the intake ports Pin1 increases, and the extremely low lift amount changes to the low lift amount. Meanwhile, the lift amount corresponding to the other intake port Pin2 and both exhaust ports Pex1 and Pex2 maintains a low lift amount.

Further, the second hydraulic control valve 63
When is switched from OFF to ON, the lift amount corresponding to the other intake port Pin2 and both exhaust ports Pex1 and Pex2 increases, and the low lift amount changes to the high lift amount.

[Operation Example of Tappet] An example of the operation of the tappet 13 will be described. First, when the intake valve 11 is lifted by the low lift amount cams 16, 16, for example, the first hydraulic control unit 61 is turned off and the plunger 47 is operated.
The hydraulic pressure to the space 52c in the back portion is released to accommodate the plunger 47 in the bush 52, and the flange portion 4 of the lock pin 48 is urged by the urging force of the spring 49.
8a and the bush 50 are brought into contact with each other so that the lock pin 48
Is positioned in the lock hole 44h.

In this way, the lock mechanism is unlocked, and the center tappet 44 can move relative to both side tappets 45, 45. In this state, the low lift amount cams 16 and 16 are attached to both side tappets 4.
The intake valve 11 can be lifted by a small lift amount by pressing the flat surfaces 45a, 45a of the valve taps 5, 45, respectively, while the center tappet 44 moves regardless of the side tappets 45, 45.

In this case, the force for pressing the side tappets 45, 45 against the tappet guide 31 is the side tappet 4
45g of 5,5 and 45 sliding contact surface and center tappet 44
44d are dispersed to the center tappet 44 side through the extended portions 44d ... 44d, that is, the receiving surfaces 44e ... 44e, so that uneven wear between the tappet 13 and the tappet guide 31 is reduced and wear resistance is improved.

A pair of springs 46, 46 for urging the center tappet 44 toward the cam are provided on both sides of the lock mechanism provided over the center tappet 44 and both side tappets 45, 45. Therefore, the relative movement amount of the center tappet 44 with respect to the side tappets 45, 45, and thus the lift amount of each valve 11, 12 in the locked state can be increased.

Since the pair of springs 46, 46 are arranged, the vertical movement of the center tappet 44 incorporated in the side tappets 45, 45 is smoother than that in the case of one spring.

Further, since the upper ends of the springs 46, 46 are arranged so as to overlap with the protruding portion 44g of the center tappet 44 through which the lock hole 44h penetrates in a side view, the springs 46, 46 are provided. Can be secured long, and the degree of freedom in designing these springs 46, 46 is increased.

When the intake valve 11 is lifted by the high lift amount cam 17, for example, the first hydraulic pressure control valve 61 is turned on to supply the working hydraulic pressure to the space 52c to resist the urging force of the spring 49. Bush 5 with plunger 47 that advances lock pin 48
When the tip of the lock pin 48 comes into contact with the stopper portion 53a of the bush 53, the lock pin 4 is moved to the 3 side.
The movement of 8 is regulated.

Thus, the one side tappet 45 and the center tappet 44 are connected through the engagement of the plunger 47 and the lock hole 44h or the bush 50, and at the same time, the center tappet 44 and the other side tappet 45 are connected. The lock pin 48 and the bush 53 are connected through engagement with each other, and the center tappet 44 and the side tappets 45, 45 are locked. In this state, when the high lift amount cam 17 pushes the flat surface 44a of the center tappet 44, the center tappet 44 and both side tappets 45, 45 move integrally, and the intake valve 11 can be lifted by a high lift amount. it can.

[Other Embodiments] Other embodiments relating to the arrangement of the cams and the supply of the operating hydraulic pressure to the tappet will be described. For the sake of convenience, the cylinders A1 to A4 and the intake and exhaust ports Pin1, Pin2, Pex1, Pex2 will be denoted by the same reference numerals used in the above description.

In the configuration shown in FIG. 9, when the first hydraulic control valve (OCV1) 161 is on, the hydraulic pressure from the oil passage 162 is the first and second main oil passages 163.
While being supplied to 164 respectively, the hydraulic pressure is released from the first and second main oil passages 163 and 164 when being off. Similarly, when the second hydraulic pressure control valve (OCV2) 165 is on, operating hydraulic pressure is supplied from the oil passage 166 to the third and fourth main oil passages 167 and 168, respectively, while when it is off, the third and the third main oil passages 167 and 168 are supplied. The hydraulic pressure is released from the four main oil passages 167 and 168.

The intake and exhaust camshafts 114,
The cam pulleys 171 and 172 are respectively attached to the front end portions of the 115, and these cam pulleys 17 and 172 are attached.
A timing belt is wound around 1,172 and a crank pulley (not shown) on the crankshaft side. And, on both of the cam shafts 114 and 115,
Actuators 173 and 174 for changing the phase angle of each camshaft 114 and 115 with respect to the crankshaft by a hydraulic control valve (not shown) are provided. By doing so, it becomes possible to closely control the combustion state of the fuel and to improve fuel efficiency.

The first main oil passage 163 has branch oil passages 163a ... 163 extending in the tappet 113 ... 113 direction.
a is formed in the same number as the cylinders A1 to A4. These branch oil passages 163a ... 163a communicate with the tappet guide corresponding to one intake port of each of the cylinders A1 to A4, and supply the working oil pressure to the tappets 113in1 ... 113in1. In addition, the tappet 113 is provided in the second main oil passage 164.
The branch oil passages 164a extending in the 113 direction are formed in the same number as the cylinders A1 to A4. 164a communicate with the tappet guide corresponding to one exhaust port of each of the cylinders A1 to A4, and supply the working oil pressure to the tappets 113ex2 ... 113ex2. That is, since the first hydraulic control valve 161 is turned on, the lift amount of the intake valve of one intake port and the exhaust valve of the one exhaust port increases.

On the other hand, the third main oil passage 167 has branch oil passages 167a ... 16 extending in the directions of the tappets 113 ... 113.
7a are formed in the same number as the cylinders A1 to A4. These branch oil passages 167a ... 167a communicate with the tappet guide corresponding to the other intake port of each cylinder A1 to A4,
The working hydraulic pressure is supplied to the tappets 113in2 ... 113in2. Further, the tappet 11 is provided in the third main oil passage 168.
168a are formed in the same number as the cylinders A1 to A4. 168a communicate with the tappet guides corresponding to the other exhaust ports of the cylinders A1 to A4 to supply the working oil pressure to the tappets 113ex1 to 113ex1.
That is, by turning on the second hydraulic control valve 165, the lift amounts of the intake valve of the other intake port and the exhaust valve of the other exhaust port increase.

Therefore, as an example, two extremely low lift amount cams and one high lift amount cam are provided in the tappets 113in1 ... 113in1 corresponding to one intake port, and the tappets 113in2 ... 113in2 corresponding to the other intake port.
2 low lift cams, 1 high lift cam, and tappet 113ex1 ... 1 for both exhaust ports
13ex1, 113ex2 ... 113ex2 are all 2
Both the hydraulic control valves 161 and 16 in the case where one low lift amount cam and one high lift amount cam are arranged.
FIG. 10 shows the lift amounts of the intake valves and the exhaust valves during the on / off operation of No. 5.

That is, both hydraulic control valves (O
When both CV1, OCV2) 161 and 165 are turned off, the lift amount corresponding to one of the intake ports Pin1 becomes an extremely low lift amount and the valve is substantially in a stopped state, and air is introduced into the combustion chamber with only one valve. Will be introduced.

Next, the first hydraulic control valve 16
When 1 goes from off to on, one intake port Pin1
Is increased from a very low lift amount to a high lift amount, and the lift amount of the exhaust valve corresponding to one exhaust port Pex2 is increased from a low lift amount to a high lift amount. Meanwhile, the other intake port Pin2
The lift amount corresponding to the other exhaust port Pex1 maintains a low lift amount.

Further, the second hydraulic control valve 16
5 turns from off to on, the other intake port Pin2
And the lift amount corresponding to the other exhaust port Pex1 increases and changes from a low lift amount to a high lift amount.

Although not described in detail, the tappets 113 ... 113 are also applied to the case of such a configuration by applying the present invention.
It is possible to further increase the relative movement amount of the center tappet with respect to the side tappet and thus the lift amount of each valve. Needless to say, the wear resistance is improved by dividing the tappet 113.

[0087]

As described above, according to the present invention,
The tappet is divided into a center tappet and side tappets located on both sides of the tappet, and extension parts extending on both sides are provided on both sides of the circumferential surface of the center tappet in the cam sliding direction so as to overlap with the circumferential surface of the side tappet. Therefore, the force of pressing the side tappet against the tappet guide is distributed to the center tappet side via the extending portion. Therefore, while ensuring the sliding length of the cam, it is possible to reduce uneven wear between the tappet and the tappet guide as in the conventional case and improve wear resistance.

Further, since a pair of springs for urging the center tappet toward the cam are arranged on both sides of the lock mechanism for engaging and disengaging the center tappet and the side tappet,
The relative movement amount of the center tappet with respect to the side tappet can be further increased, and the lift amount of each valve can be further increased. INDUSTRIAL APPLICABILITY The present invention is widely suitable for a vehicle field provided with an engine valve operating system of a type in which a valve is directly driven via a tappet.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a cylinder head of an engine according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a layout of tappets for each cylinder and a supply passage of operating hydraulic pressure to the tappets.

3 is a view taken along the line A-A in FIG.

FIG. 4 is a perspective view of a center tappet.

FIG. 5 is a perspective view of a side tappet.

FIG. 6 is a longitudinal sectional view of a main part centering on a tappet.

7 is a cross-sectional view taken along the line EE of FIG.

FIG. 8 is a diagram showing a relationship between an on / off pattern of a hydraulic control valve and a lift amount of each valve.

FIG. 9 is a schematic layout diagram showing a layout of tappets for each cylinder and a supply passage of working hydraulic pressure to the tappets according to another embodiment.

10 is a diagram showing the relationship between the on / off pattern of the hydraulic control valve and the lift amount of each valve in the configuration of FIG.

FIG. 11 is a perspective view of a conventional tappet.

[Explanation of symbols]

2 cylinder head 11 Intake valve 12 Exhaust valve 13,113 tappets 14,114 intake camshaft 15,115 Exhaust camshaft 16 Low lift cam 17 High lift cam 18 Very low lift cam 31 Tappet guide (guide hole) 31a guide groove 31b, 31c Oil receiving recess 41 Stem End 44 Center Tappet 44d extension part 44g protrusion 44h Lock hole 44j 'contact surface 45 side tappets 45d Connection part (skirt part) 45e Spring seat 45h lock hole 46 spring 47 Plunger 48 lock pin 49 spring 52 Bush 53 Bush (receiving member) 54 Ball member (anti-rotation member)

Continued front page    F term (reference) 3G016 AA06 AA08 AA12 AA19 BA03                       BA06 BA28 BA47 BB04 BB06                       CA02 CA21 CA34 CA35 CA43                       CA44 CA57 EA02 EA08 FA04                       FA13 FA26 FA36 FA37 FA38                       GA02                 3G024 AA05 AA13 AA17 BA23 DA01                       DA06 DA10 DA18 EA01 FA01                       FA06 FA07 FA14 GA07 GA10                       GA25 GA36 HA01 HA06

Claims (7)

[Claims] 1. A tappet having a cylindrical shape slidably accommodated in a guide hole provided in a cylinder head, and a cam shaft provided with a cam for driving a valve via the tappet, wherein the tappet comprises: , A substantially rectangular center tappet that is long in the sliding direction of the cam in plan view and side tappets located on both sides of the center tappet, and a lock mechanism that engages and disengages the center tappet and the side tappet is provided. And a plurality of cams having different profiles respectively corresponding to the center tappet and the side tappet on each of the tappets, and the camshaft is at least the cam of the center tappet. On both sides of the outer peripheral surface on the downstream side in the sliding direction of, there are provided extension portions extending on both sides so as to overlap the outer peripheral surface of the side tappet. In addition, the lock mechanism is arranged in the cam axis direction across the center tappet and the side tappet, and a pair of springs for urging the center tappet to the cam side are arranged on both sides thereof. Engine valve system. 2. The side tappets on both sides are connected by a cylindrical skirt portion that is in sliding contact with a guide hole on the valve side, and inside thereof, a valve stem abutting portion with which a valve stem abuts, and a pair of springs. A seat for receiving the valve-side end of the camshaft is provided, and two low lift amount cams provided on the cam shaft correspond to both side tappets, respectively, and a high lift amount positioned between these low lift amount cams. The engine valve operating system according to claim 1, wherein the quantity cam corresponds to a center tappet. 3. The lock mechanism includes lock holes provided in the center tappet and the side tappet and extending in the cam axis direction, and a lock pin slidable in the lock holes in a predetermined positional relationship between the tappets. And a plunger, and the lock hole in the center tappet is
It is provided so as to penetrate a protruding portion provided on the back side of the top surface of the tappet, and the cam-side ends of the pair of springs on both sides of the lock mechanism are overlapped with the protruding portion in a side view. The valve operating device for an engine according to claim 1 or 2, wherein the valve operating device is provided. 4. The lock pin is arranged in the lock hole of the center tappet and the plunger is arranged in the lock hole of one of the side tappets when the lock mechanism is in the unlocked state. The valve operating system for the engine according to claim 3, further comprising a spring biased to the side. 5. The lock hole of the other side tappet,
A receiving member for the lock pin protruding into the lock hole is provided, and the receiving member is engaged with a guide groove provided in the tappet sliding direction on the inner peripheral surface of the guide hole of the cylinder head to form a tappet. The engine valve operating system according to claim 4, further comprising a detent member that holds the rotation of the engine. 6. A gap is provided between the facing surfaces of the center tappet and the side tappets on both sides, and
Sleeves are fitted in the lock holes of the both side tappets, and the end portions of the center tappets of the side tappets project into the gaps. The center tappets abut the projections of these sleeves from the valve side. The valve operating device for an engine according to any one of claims 3 to 5, wherein a contact surface is provided. 7. An oil receiving recess for supplying lubricating oil to a sliding surface between the guide hole and the tappet is provided in a portion of the cylinder head around the cam side opening of the guide hole along the cam sliding direction. Claims 1 to 6 characterized in that
An engine valve operating system according to any one of 1.