JP2001227313A - Valve system device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiently of mounting work of a holder provided with a holding part to hold an energizing member to an engine main body on a valve system device of an internal combustion engine. SOLUTION: This valve system device of an internal combustion engine is furnished with energizing members 33, 34, etc., to energize locker arms 19, etc., interlocking with an engine valve composed of a suction valve and an exhaust valve by springing force and a holder 50 provided with holding parts 53, 54, etc., to hold the energizing members 33, 34, etc. Through-holes 53a, etc., passing through the holder 50 toward the locker arms 19, etc., are provided on the holding parts 53, 54, etc., are energizing members 33, 34, etc., can be installed on the holding parts after the holder 50 is installed on an opening end part of the cylinder head 1 oscillatably supporting the locker arms 19, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a rocker arm which is swung by a cam provided on a camshaft, and includes an intake valve and an exhaust valve which are engine valves which are opened and closed in conjunction with the rocker arm. In particular, the present invention relates to a structure of an urging member for urging a rocker arm toward an engine valve or a cam by an elastic force.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine provided with an urging member for urging a rocker arm, which is oscillated by a cam provided on a camshaft and interlocked with an engine valve, toward an engine valve or a cam by resilient force. Valve operating devices are known.

For example, a rocker arm pressing means as an urging member disclosed in Japanese Patent Application Laid-Open No. 4-255511 has a structure in which a cylinder is provided on a bottom surface of a rocker shaft holder which supports a rocker arm in a swingable manner. By being fitted into a circular hole of a bracket provided along the position, the bracket is supported by a rocker shaft holder coupled to the cylinder head.

However, according to this conventional technique, a rocker shaft holder itself on which a rocker arm is supported is provided with:
In addition to being provided with a bracket into which the rocker arm pressing means is fitted, and because the bracket is located near the bottom surface which is a connection part with the cylinder head, in maintenance such as replacement work of the rocker arm pressing means,
Maintenance work on the rocker arm pressing means, such as the need to remove the entire rocker shaft holder, including the rocker arm, from the cylinder head, and the need to adjust the position of the rocker arm and valve during subsequent assembly to the cylinder head Was time-consuming.

Further, another prior art, Japanese Utility Model Laid-Open Publication No.
In the valve train of an internal combustion engine disclosed in Japanese Patent Application Publication No. 06-2006, a pair of cylinders are in contact with a raised portion provided on a camshaft and a low-speed cam for each cylinder, and are also operatively connected to a pair of intake valves. A free rocker arm is provided which is in contact with the drive rocker arm and the high-speed cam and can be free with respect to the intake valve, and further includes a connection switching mechanism capable of switching connection and disconnection of the rocker arms. During low-speed operation of the engine, the free rocker arm oscillated by the high-speed cam idles independently of the intake valve. Therefore, a lost motion mechanism is provided as an urging member for elastically urging the free rocker arm toward the cam in order to prevent the free rocker arm from being hit by the high-speed cam. The lost motion mechanism is fitted to a bottomed cylindrical portion provided on a support plate fixed to a holder coupled to the cylinder head and having an open end that opens downward.

According to this another conventional technique, since a support plate on which a lost motion mechanism is fitted is attached to a holder on which each rocker arm is already swingably supported, maintenance of the lost motion mechanism is performed. In this case, it is only necessary to remove only the support plate from the holder on which each rocker arm is supported, so that maintenance work of the lost motion mechanism is facilitated.

[0007]

However, since the lost motion mechanism as the urging member is merely fitted to the bottomed cylindrical portion, the support plate is already supported so that each rocker arm can swing. When attaching to the holder, the lost motion mechanism may deviate from its proper position due to contact with other members or fall off from the cylindrical part with the bottom. did. In addition, there were cases where the mounting operation of the support plate became difficult due to the resilience of the lost motion mechanism.

The present invention has been made in view of such circumstances, and a first aspect of the present invention provides a valve operating device for an internal combustion engine in which a holding portion for holding an urging member is provided. It is a common object to improve the efficiency of the work of attaching the holder provided with the to the engine body, and the invention according to claim 2 further provides an urging member that can easily adjust the elasticity of the rocker arm. Another object of the present invention is to realize lubrication of the urging member with a simple structure.

[0009]

Means for Solving the Problems and Effects of the Invention The invention according to claim 1 of the present application is directed to a rocker arm which can be swung directly or indirectly by a cam provided on a cam shaft to interlock with an engine valve, and An urging member for urging the rocker arm toward the engine valve or the cam by a resilient force, and holding the urging member by attaching the rocker arm to an open end of an engine body on which the rocker arm is swingably supported. And a holder provided with a holding portion, wherein the holding portion is provided with a through-hole passing through the holder toward the rocker arm, and the biasing member is provided with an anti-rocker arm. A valve operating device for an internal combustion engine, which is formed so as to be mounted in the through hole from an opening end on the side.

According to the first aspect of the present invention, after the holder is attached to the engine body, by using the through hole, the urging member can be attached to the holder from the opening end of the holder on the side opposite to the rocker arm. Therefore, at the time of mounting the holder, the biasing member does not deviate from the regular position in the holding portion, there is no risk of falling off from the holding portion, and further, the mounting of the holder becomes difficult due to the elastic force of the biasing member, The efficiency of the holder mounting operation is improved. In addition, at the time of maintenance of the urging member, the urging member can be pulled out from the holding portion, so that it is not necessary to remove the holder from the engine body,
Maintenance work of the urging member becomes extremely easy.

According to a second aspect of the present invention, in the valve train of an internal combustion engine according to the first aspect, the biasing member is a position-adjustable fixing piece for holding the biasing member on the holding portion. And the elastic force is adjusted by adjusting the position of the fixed piece.

According to the second aspect of the present invention, since the position of the fixing piece is freely adjustable, by adjusting the position of the fixing piece with respect to the holding portion, the elasticity of the rocker arm can be adjusted. The adjustment of the resilience when the member is mounted on the holder and the adjustment of the resilience when the resilience changes over time can be easily performed by adjusting the position of the fixing piece.

According to a third aspect of the present invention, in the valve train of the internal combustion engine according to the second aspect, the urging member is provided between a contact piece that contacts the rocker arm and the fixed piece and the corresponding contact piece. And a resilient member having the resilient force for urging the contact piece toward the rocker arm. The fixed piece is opened toward the upper space and has the contact piece and the elastic member. An oil supply hole for supplying lubricating oil is provided in the generating member.

According to the third aspect of the invention, in the space where the valve gear is disposed, the splash of the lubricating oil supplied to the sliding portion of the valve gear is directed toward the space above the fixed piece. Is supplied directly to the contact piece of the urging member and the resilient member through the oil supply hole through the oil supply hole directly or from the oil supply hole that is opened or adheres to the fixed piece to form a liquid flow, and the sliding portions thereof are lubricated. . Here, since the oil supply hole is provided in the fixed piece, it is not necessary to provide a structure for oil supply in the holder and the holding portion, and a supply path of the lubricating oil to the urging member can be formed with a simple structure.

Further, the oil supply hole makes it possible to visually check whether the contact piece or the resilient member has fallen off when the urging member is mounted on the holding portion, and it is possible to assure a reliable assembly. Become. Further, the weight of the urging member itself can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the internal combustion engine is a 6-cylinder V-type SOHC internal combustion engine for a vehicle, and the cylinders forming one bank of the internal combustion engine are in an engine operation range where fuel efficiency is important such as a low load operation range. The opening and closing operations of the intake valves and the exhaust valves of these cylinders are stopped, and the cylinders are brought into a stopped state.

Referring to FIG. 1, FIG. 3 to FIG. 5, in a bank on the deactivated cylinder side, a cylinder which is coupled to a cylinder block (not shown) and constitutes a part of the engine body of the internal combustion engine together with the cylinder block. The head 1 has an intake valve 5a which is a pair of engine valves for opening and closing the intake ports of a pair of intake ports 3 opened to the combustion chamber 2 for each of the three cylinders A1, A2, A3 arranged along the crankshaft. , 5b and combustion chamber 2
Exhaust valves 6a and 6b, which are a pair of engine valves, that open and close the exhaust ports of the pair of exhaust ports 4 that open to the outside. A cylinder head cover is connected to the upper end surface of the cylinder head 1 to form a sealed valve operating chamber in which the valve operating device is housed. FIG. 1 shows a portion corresponding to each cylinder,
These are indicated by reference signs A1, A2, and A3.

In each cylinder A1, A2, A3, a pair of intake valves
5a and 5b are slidably fitted to a stem guide 7 press-fitted into the cylinder head 1 and are compressed by a valve spring 11 mounted between the cylinder head 1 and a flange 9 at a valve stem end. , And are biased in the valve closing direction. Similarly, a pair of exhaust valves 6
a and 6b are also slidably fitted to a stem guide 8 press-fitted into the cylinder head 1, and are compressed by a valve spring 12 mounted between the cylinder head 1 and a flange 10 at the valve stem end. , And are biased in the valve closing direction.

A camshaft 13 rotatably driven at a reduction ratio of 1/2 by a crankshaft of the internal combustion engine is rotatably supported by the cylinder head 1. The camshaft 13 has an intake cam 14, a pair of exhaust pause cams 15a and 15b located on both sides of the intake cam 14 along the camshaft 13, and an intake cam 14 for both exhaust pause cams 15a and 15b. A pair of exhaust cams on the opposite side
16a and 16b are provided. The intake cam 14 has a profile consisting of a lift portion for opening and closing the pair of intake valves 5a and 5b during normal operation of the internal combustion engine and a base circle portion, and both exhaust stop cams 15a and 15b Has a profile consisting of only a base circle portion that closes the exhaust valves 6a and 6b,
Each of the exhaust cams 16a and 16b has a profile including a lift portion and a base circular portion that respectively open and close the pair of exhaust valves 6a and 6b during normal operation of the internal combustion engine.

Between the pair of intake valves 5a, 5b and the camshaft 13, there are first and second intake rocker arms 17, 18, and a third intake rocker arm 19 located between the two intake rocker arms 17, 18.
Are swingably supported above the camshaft 13 in a state of being arranged in parallel with the intake rocker arm shaft 20 fixed to the cylinder head 1. On the other hand, between the pair of exhaust valves 6a, 6b and the camshaft 13, the first and second exhaust rocker arms 21, 22 and the third and third exhaust rocker arms 21, 22 located on both sides thereof with the exhaust rocker arms 21, 22 therebetween.
The fourth exhaust rocker arms 23 and 24 are swingably supported above the cam shaft 13 in a state of being arranged in parallel with an exhaust rocker arm shaft 25 fixed to the cylinder head 1.

In each of the first and second intake rocker arms 17 and 18, one end is supported by an intake rocker arm shaft 20, and the other end is provided with a tappet screw which is in contact with the valve stem end of the intake valves 5a and 5b. 26 is provided so as to be able to advance and retreat, and a first connection switching mechanism M1 described later is provided at an intermediate portion thereof.
Also, as shown in FIG. 3, the third intake rocker arm
A roller 28 slidingly in contact with the intake cam 14 is rotatably supported at one end of the 19, and a first connection switching mechanism M 1 is provided at the other end, and an intermediate portion thereof is supported by the intake rocker arm shaft 20. Therefore, the first and second intake rocker arms 17 and 18 are connected to both intake valves 5.
a, 5b, respectively, the third intake rocker arm 19,
It is swung directly by the intake cam 14.

On the other hand, the first and second exhaust rocker arms 21 and 22
At one end, an exhaust pause cam 15
A roller 29 having a second connection switching mechanism M2, which will be described later, is rotatably supported, and a tappet screw 27 abutting on the valve stem end of the exhaust valves 6a, 6b advances and retreats at the other end. It is provided freely, and the middle part is the exhaust rocker arm shaft
Supported by 25. As shown in FIG. 7, the roller 29 includes an inner ring 29a press-fitted and fixed to the first and second exhaust rocker arms 21 and 22, an outer ring 29b slidably contacting the exhaust pause cams 15a and 15b, and an inner ring 29a and an inner ring 29a, respectively. And a number of rollers 29c arranged between the outer rings 29b. Further, in each of the third and fourth exhaust rocker arms 23 and 24, a roller 30 having a built-in second connection switching mechanism M2 is supported at one end by sliding contact with the exhaust cams 16a and 16b. The end is supported by the exhaust rocker arm shaft 25. Roller 30
The inner ring 30a is press-fitted and fixed to the third and fourth exhaust rocker arms 23 and 24, and the outer ring 30b is in sliding contact with the exhaust cams 16a and 16b.
It comprises a number of rollers 30c arranged between the inner ring 30a and the outer ring 30b. Therefore, the first and second exhaust rocker arms 21 and 22 are interlocked with the two exhaust valves 6a and 6b, respectively,
The fourth exhaust rocker arms 23 and 24 are directly swung by the two exhaust cams 16a and 16b, respectively.

Thus, the first and second intake rocker arms
Reference numerals 17 and 18 denote free rocker arms which can be free without being restricted by the movement of the intake cam 14. The third intake rocker arm 19 is provided with both intake valves 5a and 5b without opening and closing the intake valves. A free rocker arm that can be free for 5a and 5b. Similarly, the third and fourth exhaust rocker arms
Each of 23 and 24 is a free rocker arm that can be free with respect to the exhaust valves 6a and 6b without opening and closing the exhaust valves 6a and 6b. Further, the one end of the third intake rocker arm 19 is located above the camshaft 13 and the first exhaust rocker arm 21.
Is located adjacent to the one end of the second exhaust rocker arm 22 along the camshaft 13 in parallel.

In the cylinder head 1 in which the rocker arms 17 to 19 and 21 to 24 are already swingably supported, the end faces on the side opposite to the connecting face with the cylinder block with the cam shaft 13 interposed therebetween. On the upper end surface which is the open end of the cylinder head 1, the cylinder head 1 is arranged in the cylinder arrangement direction of the three cylinders A1, A2, A3, that is, in the axial direction L of the cam shaft 13.
The plate-like holder 50 shown in FIG. 2 is provided with ten fastening members, bolts B1 to B10, from one end to the other end.
(See FIG. 1).

In this holder 50, for each cylinder A1, A2, A3, first and second intake rocker arms 17, 18 are respectively attached to the valve stem ends of both intake valves 5a, 5b via tappet screws 26. The first and second lost motion mechanisms 31 and 32 as urging members for urging toward the intake cam 14 toward the intake cam 14 as urging members. The third lost motion mechanism 33 and the third and fourth exhaust rocker arms 23 and 24 are respectively connected to both exhaust cams 16.
Fourth and fifth lost motion mechanisms 34 and 35 as urging members for urging toward a and 16b by resilient force are formed with first to fifth holding parts 51 to 55 which are respectively mounted and held. Is done. Further, fastening portions C1 to C10 formed of cylindrical bosses having bolt insertion holes are formed in the holder 50 corresponding to the bolts B1 to B10.

Here, the third lost motion mechanism 33 attached to the third holding portion 53 will be described with reference to FIGS. 3 and 8, but the first, second, fourth, and fifth lost motion mechanisms will be described. Each of 31, 32, 34, and 35 has basically the same structure as the third lost motion mechanism 33.

The third holding portion 53 penetrates the holder 50 from the rocker arm side 50a where the rocker arms 17 to 19 and 21 to 24 are disposed to the anti-rocker arm side 50b opposite to the rocker arm side 50a. , Having a through hole 53a facing the third intake rocker arm 19, and a rocker arm side 50a
It has a partially cylindrical shape having a first opening end 53b that is open to the outside and a second opening end 53c that opens to the side 50b opposite to the rocker arm, and protrudes toward the side 50b opposite to the rocker arm of the holder 50.

The third lost motion mechanism 3 attached to the through hole 53a from the side 50b opposite to the rocker arm 50b of the holder 50.
Reference numeral 3 denotes a contact piece that is located near the first opening end 53b and contacts a contact surface 19a formed on the upper part of the third intake rocker arm 19.
1, a fixing piece 42 screwed into a screw portion 53d formed near the second opening end 53c inside the third holding portion 53, and the third suction rocker arm 19 is connected to the suction cam 14 via a contact piece 41. And a cylindrical coil spring 43 which is a resilient member held between the fixed piece 42 and the abutting piece 41 so as to be urged by the resilient force toward the spring. The outer periphery of the coil spring 43 is in contact with the inner peripheral surface of the third holding portion, and guides the coil spring 43 along the through hole 53a.

The contact piece 41 includes a collar-shaped retainer 41a that contacts one end of the coil spring 43, and a column-shaped fitting portion 41b that is fitted and held on the inner periphery of the coil spring 43. Further, the fixing piece 42 is in contact with the other end of the coil spring 43, and a retainer portion 42a having a threaded portion 42d formed on the outer peripheral surface thereof, and a cylindrical fitting fitted and held on the inner periphery of the coil spring 43. Joint 42b,
And a flange portion 42c abutting on the second open end 53c. Further, the fixing piece 42 is attached to the third holding section 53 in order to mount the third lost motion mechanism 33 on the third holding section 53.
A hexagonal hole 42e, which is a tool insertion hole into which a tool for screwing into the hole is inserted, is further formed.
An oil supply hole 42f penetrating through e is formed. The oil supply hole 42f has an upper end opening toward the upper space of the valve operating chamber, and a lower end opening at the end face of the fitting portion 42b on the contact piece 41 side. The droplets of the lubricating oil supplied to the sliding portions of the third lost motion mechanism 33 directly from the oil supply hole 42f or adhere to the fixed piece 42 to form a liquid flow through the oil supply hole 42f. It is supplied to 41 and the coil spring 43 to lubricate their sliding parts.

Therefore, the screw portion 42d of the fixing piece 42 and the screw portion 53d of the third holding portion 53 are screwed together so that the third lost motion mechanism 33 is screwed and fixed to the third holding portion 53 or temporarily. After screwing and fixing, the fixing piece 42 is rotated to advance and retreat in the axial direction of the through hole 53a, that is, in the direction of the center line of the coil spring 43, thereby adjusting the position of the fixing piece 42 with respect to the third holding portion 53. By doing so, the elastic force of the coil spring 43 can be adjusted.

By the way, the first, second, fourth, fifth and fourth lost motion mechanisms 31, 32, 34, 35 having the same structure as the third lost motion mechanism 33 are mounted. , The fifth holding portions 51, 52, 54, 55 have basically the same structure as the third holding portion 53, respectively.
a, 52a, 54a, 55a, second open ends 51c, 52c, 54c, 55c, screw portions 51d, 52d, 54d, 55d, and the like. These lost motion mechanisms 31 to 35 are mounted on the corresponding holding parts 51 to 55 in basically the same manner.

Therefore, the contact piece 41 of the first and second lost motion mechanisms 31 and 32 is attached to the first and second intake rocker arms 1 and 2.
Contact surfaces 17a, 18a formed on the upper portions of 7, 18 (see FIG. 1)
Are in contact with each other. The contact pieces 41 of the fourth and fifth lost motion mechanisms 34 and 35 are respectively provided on contact surfaces 23a and 24a formed on the upper portions of the third and fourth exhaust rocker arms 23 and 24 (FIG. 1).
Reference). And these first to first
The fifth holding portions 51 to 55 are provided on the holder 50 so as to be inclined with respect to the coupling surface between the cylinder block and the cylinder head 1, that is, the center lines of the cylinders of the first to fifth holding portions 51 to 55 are inclined. Can be

As shown in FIG. 6, a first connection switching mechanism M1 provided on the first, second, and third intake rocker arms 17, 18, 19 includes a piston 60, A connecting pin 61 for connecting the intake rocker arms 17 and 19, and a connecting piston 62 for restricting movement of the piston 60 and the connecting pin 61 and connecting the second and third intake rocker arms 18 and 19;
And a return spring 63 for urging the piston 60 and the connecting pin 61 toward the connecting side.

The first intake rocker arm 17 has a piston 60
And a guide hole with a bottom in which the connecting pin 61 is slidably fitted
A hydraulic chamber 64 is formed with its open end facing the third intake rocker arm 19 and between the piston 60 and the bottom of the guide hole 64.
67 is formed. Further, the hydraulic chamber 67 communicates with a hydraulic supply passage 69 (FIG. 4) inside the intake rocker arm shaft 20 via a communication passage 68.
) And the first intake rocker arm 17 regardless of the swinging state. A guide hole 65 having the same diameter is formed in the third intake rocker arm 19 at a position corresponding to the guide hole 64 with both open ends thereof facing the first and second intake rocker arms 17 and 18, respectively. The connecting pin 61 and the connecting piston 62 are slidably fitted on the connecting pin 61 and the connecting piston 62. A guide hole 66 having the same diameter and a bottom is formed in the second intake rocker arm 18 at a position corresponding to the guide hole 65 with its open end facing the third intake rocker arm 19. Are slidably fitted. The return spring 63 is mounted on the inner periphery of the connecting piston 62 in a compressed state between the bottom of the guide hole 66 and the connecting piston 62.

The hydraulic pressure in the hydraulic pressure supply passage 69 controlled by the hydraulic pressure control valve causes the hydraulic pressure chamber 67 of the first connection switching mechanism M1 to operate.
When the hydraulic pressure is low, the piston 60, the connecting pin 61, and the connecting piston 62 move toward the connecting side by the elastic force of the return spring 63, and the connecting pin 61 is fitted across the two guide holes 64, 65. At the same time, the connecting piston 62 is fitted over the two guide holes 65 and 66, and the first, second, and third intake rocker arms 17, 18, and
19 is in a connected state of being integrally connected. When the hydraulic pressure in the hydraulic chamber 67 is increased by the hydraulic control valve, the piston 60 moves to a position where the connecting pin 61 is pushed into the third intake rocker arm 19, and the contact surface between the piston 60 and the connecting pin 61 is moved. Are located between the first and third intake rocker arms 17 and 19, and the contact surface between the connecting pin 61 and the connecting piston 62 is located between the second and third intake rocker arms 18 and 19, so that the first , The second and third intake rocker arms 17, 18, and 19 are in a disconnected state in which they are not connected.

On the other hand, the first and third exhaust rocker arms 21 and 23
As shown in FIG. 7, the second connection switching mechanism M2 is provided with a piston 70 and the first and third exhaust rocker arms 2.
A connecting pin 71 for connecting the first and the second 23, a regulating piston 72 for regulating the movement of the piston 70 and the connecting pin 71, and a piston
70, a connecting pin 71 and a return spring 73 for urging the regulating piston 72 toward the connecting side. The first exhaust rocker arm 21 has a bottomed mounting hole 21a into which the inner ring 29a of the roller 29 is press-fitted and fixed.
Is formed with its open end facing the third exhaust rocker arm 23, and a piston 70 is formed in a guide hole 74 formed in the inner race 29a.
And the connecting pin 71 are slidably fitted. The hydraulic chamber 7 formed between the piston 70 and the bottom of the bottomed mounting hole 21a
6 always communicates with the hydraulic supply path 78 (see FIG. 4) inside the exhaust rocker arm shaft 25 via the communication path 77 regardless of the swing state of the first exhaust rocker arm 21. In the third exhaust rocker arm 23, a bottomed mounting hole 23b into which the inner race 30a of the roller 30 is press-fitted and fixed is formed with its open end facing the first exhaust rocker arm 21, and a guide hole 74 is formed in the inner race 30a.
The connecting pin 71 and the restricting piston 72 are slidably fitted in the guide holes 75 having the same diameter formed at positions corresponding to the positions. The return spring 73 is located inside the regulating piston 72 and has a bottomed mounting hole 23b.
It is mounted in a compressed state between the bottom of the piston and the regulating piston 72.

The hydraulic pressure in the hydraulic supply passage 78 controlled by the hydraulic control valve causes the hydraulic chamber 76 of the second connection switching mechanism M2 to operate.
When the hydraulic pressure is lowered, the piston 70, the connecting pin 71, and the regulating piston 72 move toward the connecting side by the elastic force of the return spring 73, and the connecting pin 71 fits across the guide holes 74 and 75. As a result, the first and third exhaust rocker arms 21 and 23 are connected to be integrally connected. In addition, the hydraulic chamber 76 is controlled by the hydraulic control valve.
When the hydraulic pressure is increased, the piston 70 moves to a position where the connecting pin 71 is pushed into the third exhaust rocker arm 23, and the contact surface between the piston 70 and the connecting pin 71 is moved to the first and third exhaust rocker arms 21,. 23, the first and third exhaust rocker arms 21 and 23 are in a disconnected state in which they are not connected.

Further, the second and fourth exhaust rocker arms 22, 24 are provided.
Also provided is a second connection switching mechanism M2 having the same structure as the second connection switching mechanism M2 provided on the first and third exhaust rocker arms 21 and 23, and when the hydraulic pressure in the hydraulic chamber 76 is low,
The piston 70, the connecting pin 71, and the regulating piston 72 are moved toward the connecting side by the resilience of the return spring 73, and the connecting pin 71 is fitted over the guide holes 74 and 75 to form the second and fourth exhaust ports. The rocker arms 22 and 24 are in a connected state of being integrally connected. When the hydraulic pressure in the hydraulic chamber 76 becomes high, the piston 70 moves to a position where the connecting pin 71 is pushed into the fourth exhaust rocker arm 24,
Since the contact surface between the piston 70 and the connecting pin 71 is located between the second and fourth exhaust rocker arms 22 and 24, the second and fourth exhaust rocker arms 22 and 24 are in a disconnected state where they are not connected.

Here, the cam shaft 13 provided with the cam, each rocker arm 17-19, 21-24, each rocker arm shaft 20, 25, the intake valves 5a, 5b, the exhaust valves 6a, 6b, the holder 50, A valve train is constituted by members attached thereto.

Next, referring to FIGS. 1 and 2, the holding portions 51 to 55 and the fastening portions C projecting from the side 50b opposite to the rocker arm 50b.
The holder 50 in which 1 to C10 and the reinforcing rib are integrally formed by casting will be further described. In the cylinder A1, the side surfaces of the first and second holding portions 51 and 52 are directly connected to both side surfaces in the axial direction L of the cam shaft 13 of the third holding portion 53.

The third holding portion 53 is located on the opposite side of the axis of the cam shaft 13 from the side where the second opening end 53c is located, passes through the center line of the cylinder of the third holding portion 53, and The fourth and fifth holding parts 54 and 55 are arranged so that the second opening ends 54c and 55c are located substantially symmetrically with respect to a plane P orthogonal to the axis.
Between 55, the upper portions of the first and second exhaust rocker arms 21 and 22 are inserted into the concave portion 56 formed by lightening. The arrangement of the first to fifth holding parts 51, 52, 53, 54, 55 in the holder 50 is the same for the remaining two cylinders A2, A3. Further, a pipe 39 into which an ignition plug is inserted is disposed between the first and second exhaust rocker arms 21 and 22 and near an end where the tappet screws 27 and 27 are provided.

Also, fastening portions C1 to C10 to which bolts B1 to B10 for fastening the holder 50 to the cylinder head 1 are inserted and fastened.
10 are arranged as follows. Of the three cylinders A1, A2, A3 arranged in a line, the cylinder A1 located at one end is closest to one end of the holder 50 among the holding portions 51, 52, 53, 54, 55 of the cylinder A1. On the side of the located fourth holding portion 54 near the one end of the holder 50 in the axial direction L of the camshaft 13, the fastening portion C1 is a position where the side surface thereof is directly connected to the side surface of the fourth holding portion 54. Is provided.

In the first and second holding portions 51 and 52,
Two fastening portions C2 and C3 are provided on the side opposite to the side where the third holding portion 53 is located in the axial direction L of the camshaft 13, respectively. Fourth ribs 84, 84 connect the side surfaces of the portions C2, C3, respectively.

Further, on the side of the fifth holding portion 55, which is closest to the cylinder A2 among the holding portions 51 to 55 of the cylinder A1, in the axial direction L of the camshaft 13 and closer to the cylinder A2, a fastening portion C4 is provided. It is provided at a position where the side surface and the side surface of the fifth holding portion 55 are directly connected. Further, in the fastening portion C4, the side surface on the side opposite to the side where the fifth holding portion 55 is located in the axial direction L of the camshaft 13 is located closest to the cylinder A1 in the holding portions 51 to 55 of the cylinder A2. 4 is directly connected to the side surface of the holding portion 54.

The cylinders A2 and A3 have the same arrangement of the holding parts 51 to 55 and the fastening parts C4 to C7 as the cylinder A1. That is, in the cylinder A2, the fastening portion C4 is located at a position directly connected to the side surface of the fourth holding portion 54 on the side of the fourth holding portion 54 near the cylinder A1 in the axial direction L of the camshaft 13 as described above. Is provided. In the first and second holding portions 51 and 52, two fastening portions provided on the side of the cam shaft 13 in the axial direction L.
The side surfaces of C5 and C6 are connected by fourth ribs 84 provided between the side surfaces of the first and second holding portions 51 and 52, respectively. Further, the fastening portion C7 whose side surface is directly connected to the side surface of the fourth holding portion 54 in the cylinder A3 is connected to the cylinder A3 in the axial direction L of the cam shaft 13.
The side opposite to the side where the fourth holding part 54 is located is provided at a position directly connected to the side of the fifth holding part 55 located closest to the cylinder A3 among the holding parts 51 to 55 of the cylinder A2. Can be

Similarly, in the cylinder A3, the fastening portion C7 is
In the axial direction L of the camshaft 13 of the holding portion 54, on the side near the cylinder A2,
It is provided at a position directly connected to the side surface of the fourth holding portion 54. In the first and second holding portions 51 and 52, the camshaft 13
Two fastening portions C8, C9 provided on the side in the axial direction L of
Are connected by fourth ribs 84, 84 provided between the side surfaces of the first and second holding portions 51, 52. Furthermore, the fastening part C1
0 is the cam shaft of the fifth holding portion 55 whose side face is located closest to the other end of the holder 50 among the holding portions 51 to 55 of the cylinder A3.
13 is provided at a position directly connected to the side surface of the fifth holding portion 55 on the side near the other end of the holder 50 in the axial direction L.

Then, of these fastening portions C1 to C10, the cam shaft 13 is adjacent to the cam shaft 13 on the side where the first, second, and third holding portions 51, 52, and 53 are directly connected to each other. cylinder
The ends of the holders 50 of the joints C2 and C9 located between the joints C3 and C5 between A1 and A2, between the joints C6 and C8 between the cylinders A2 and A3, and at the ends of the cylinders A1 and A3 at both ends. A concave portion 57 is formed near the portion by lightening, and a coupling member for coupling the cylinder head 1 to the cylinder block, for example, an insertion hole through which a bolt is inserted, is formed in the cylinder head 1 corresponding to the position of the concave portion 57. 58 are formed. The joints C3, C5, C6, and C8 between the adjacent cylinders have cutouts 59 at their opposing sides so that the coupling member does not interfere with the joints C3, C5, C6, and C8. Are provided, and the fastening portions C2 and C9, which are located near both ends, have similar cutouts near the ends.
59 are provided.

The first and second lost motion mechanisms 3
1 and 32, when both intake valves 5a and 5b are closed, and in the third, fourth and fifth lost motion mechanisms 33 to 35, the third intake rocker arm 19 is operated by the intake cam 14 or the exhaust cams 16a and 16b. Or the third and fourth exhaust rocker arms 23,
When the 24 swings, the spring force due to the compression of the coil spring 43 acts on the holding portions 51 to 55. Therefore, the holder 50 is provided with a plurality of ribs for increasing its rigidity in order to oppose the load acting on the holder 50 and to suppress the generation of vibration due to the operation of the valve train. Of these ribs, the first rib 81
Is connected to the side surface in the axial direction L of the cam shaft 13 at a substantially central position of the length of the third holding portion 53 of each of the cylinders A1, A2, A3 in the center line direction, and extends along the axial direction L of the cam shaft 13. And extend linearly.

Further, in each of the cylinders A1, A2, A3, the second rib 82 is connected to the center line of the fourth holding portion 54, 54, 54 and the fastening portion C.
A rib 82a extending linearly so as to connect the two sides along a plane including the center lines of C5, C8, and fifth holding portions 55, 5;
The ribs 82b extend linearly so as to connect the two side surfaces along a plane including the center lines of 5, 55 and the center lines of the fastening portions C3, C6, C9. The second rib 82 is connected to the fourth and fifth holding portions 54 and 55 and the fastening portions C2, C5 and C5.
8, C3, C6, C9, so as to intersect with the first rib 81,
In this embodiment, they extend substantially orthogonally, and are connected to the first rib 81 at the intersection.

In the cylinder A1, the third rib 83 is connected to the connecting portion D of the third holding portion 53 with the first rib 81, the side surface of the fastening portion C1 directly connected to the side surface of the fourth holding portion 54, and the fourth portion. 5 Holder 55
And extends linearly so as to connect the side surface of the fastening portion C4 directly connected to the side surface thereof. Further, the third rib 83 is a cylinder
A2 and A3 are the same as the cylinder A1, and the cylinder A2 has a connection portion D with the first rib 81 of the third holding portion 53 and a fastening portion.
It extends linearly to connect the side surface of C4 and the side surface of the fastening portion C7. For the cylinder A3, the connection portion D of the third holding portion 53 to the first rib 81, the side surface of the fastening portion C7 and the fastening Part C10
It extends linearly to connect to the side surface. These third ribs 83 are formed by the second rib 82 and the fourth and fifth holding portions 54,
They intersect near 55 and are connected to the second rib 82 at the intersection.

The first, second and second holding members are directly connected to each other.
The third holding portions 51, 52, 53 are connected to the first and second ribs 81, 82 and the third and fourth ribs 83, 84 connected to the fastening portions C1 to C10, and the fourth and fifth holding portions 54 are provided. , 55 are fastening parts C1, C4, C7,
Bolts B1, B4, B7, B10 inserted into C10 and fastening part C
2, C3, C5, C6, C8, C9 connected second and third ribs 82,
Since the holder 50 is connected, the rigidity of the entire holder 50 is increased, the operation of the valve train is stabilized, and vibration is suppressed, and noise is reduced.

Each of the fourth and fifth holding portions 54 and 55 has a fastening portion C which is connected to the cylinder head 1 in the holder 50.
1, C4, C7, and C10 are directly connected and integrated, so the rigidity between the holding portions 54 and 55 is increased,
Deformation between the holding portions 54 and 55 can be suppressed, and the failure of the fourth and fifth lost motion mechanisms 34 and 35 occurs, for example, the elasticity becomes weaker than the set elasticity of the coil spring 43. In addition, the action direction of the resilient force may deviate from the set direction, or the sliding motion of the sliding portion between the coil spring 43 and the inner peripheral surfaces of the first to fifth holding portions 51 to 55 may not be performed smoothly. Is suppressed. Further, the fastening portions C1, C4, where the holding portions 54, 55 are located,
Since the vicinity of C7 and C10 has high rigidity, the third and fourth
The deformation of the entire holder 50 due to the load acting via the fourth and fifth lost motion mechanisms 34 and 35 based on the swing of the exhaust rocker arms 23 and 24 can be suppressed.

The holder 50 has first ribs 81 extending along the axial direction L of the camshaft 13 and connecting the third holding portions 53 of the cylinders A1, A2, A3 to each other, and fourth and fifth holding portions. 54, 55 and fastening part C2,
Second ribs 82 are provided to connect C3, C5, C6, C8, and C9, respectively. The second ribs 82 are provided between the fourth holding portion 54 and the fastening portions C2, C5, and C8, and the second rib 82. 5 Holding part 55 and fastening part C3,
The first rib 81 is connected between C6 and C9. As a result, the first rib 81 and the second rib 82 are intersected with each other, so that the rigidity of the entire holder 50 is increased, so that the occurrence of troubles of the lost motion mechanisms 31 to 35 is further suppressed, and The operation of the valve gear is stabilized, and furthermore, vibration is suppressed and noise is reduced. Further, as in the embodiment,
When the first rib 81 and the second rib 82 intersect substantially orthogonally, the rigidity is further increased.

In the valve train configured as above,
When the internal combustion engine is operated, during normal operation in which the cylinder deactivation operation is not performed, the hydraulic pressure chamber 67 of the first connection switching mechanism M1 is set to a low pressure, so that the first, second, and third intake rocker arms 17, 18, and 19 are operated. Are in a connected state, and the first and second intake rockers 19 are in contact with the pair of intake valves 5a and 5b by the intake cam 14 in sliding contact therewith.
The second intake rocker arms 17 and 18 are the third intake rocker arms 19
Therefore, the two intake valves 5a and 5b are opened and closed by a valve opening characteristic determined by the intake cam 14. therefore,
The first and second intake rocker arms 17 and 18 are indirectly oscillated by the two intake cams 14, respectively.
Is linked with the intake valves 5a and 5b.

On the other hand, at this time, the two second connection switching mechanisms M2,
Since the pressure in the hydraulic chamber 76 of M2 is low, the first and third exhaust rocker arms 21 and 23 and the second and fourth exhaust rocker arms 2
Exhaust cams 16a and 16b are connected to each other, and the third and fourth exhaust rocker arms 23 and 24 are in sliding contact with each other.
Accordingly, the first exhaust rocker arm 21 in contact with the exhaust valve 6a swings integrally with the third exhaust rocker arm 23, and the second exhaust rocker arm 22 in contact with the exhaust valve 6b swings integrally with the fourth exhaust rocker arm 24. The exhaust valves 6a, 6b are opened and closed with valve opening characteristics determined by the exhaust cams 16a, 16b, respectively. Therefore, the first and second exhaust rocker arms 21 and 22
Are rocked indirectly by the two exhaust cams 16a, 16b, respectively, and the third and fourth exhaust rocker arms 23, 24
Works with a and 6b respectively.

During the cylinder deactivated operation in which the internal combustion engine is operated in an engine operation range that emphasizes fuel efficiency, such as a low load operation range, the hydraulic chamber 67 of the first connection switching mechanism M1 is set to a high pressure, so , The third intake rocker arms 17, 18, and 19 are in a disconnected state, and the pair of intake valves 5a and 5b are connected to the third intake rocker arms 19 and 18.
Since the valve opening force of the intake cam 14 is not transmitted through the intake cam 14, the intake valves 5a and 5b are normally closed.

Then, the first and second intake rocker arms 17,
Reference numeral 18 always maintains an appropriate valve clearance even during the cylinder deactivated operation by the resilience of the coil spring 43 of the first and second lost motion mechanisms 31, 32. Also, the third
Although the intake rocker arm 19 is urged to slide on the intake cam 14 by the resilient force of the coil spring 43 of the third lost motion mechanism 33, it moves idly, but the coil spring 43 of the third lost motion mechanism 33 moves. By expanding and contracting, the third intake rocker arm 19 is prevented from ramping up.

The hydraulic chambers of the two second connection switching mechanisms M2, M2
Since 76 is set to high pressure, the first and third exhaust rocker arms 2
1, 23, and the second and fourth exhaust rocker arms 22, 24,
The third and fourth exhaust rocker arms 23 and 24 are in the disconnected state, and the paused exhaust cams 16a and 16b that are in sliding contact with each other.
As a result, the valve is normally closed. The third and fourth exhaust rocker arms 23 and 24 are urged to slide on the exhaust cams 16a and 16b by the elastic force of the coil springs 43 of the fourth and fifth lost motion mechanisms 34 and 35, respectively. Thus, the coil spring 43 of the fourth and fifth lost motion mechanisms 34 and 35 expands and contracts, thereby preventing the third and fourth exhaust rocker arms 23 and 24 from running out.

The operation and effect of the embodiment configured as described above will be described below. After attaching the holder 50 to the cylinder head 1, the first to fifth holding units 51 to hold the first to fifth lost motion mechanisms 31 to 35, respectively.
By using the through holes 51a to 55a of the holder 55, the first to fifth lost motion mechanisms 31 to 35 can be moved from the second opening ends 51c to 55c on the side 50b opposite to the rocker arm 50b of the holder 50.
Since there is no risk that the lost motion mechanisms 31 to 35 will be displaced from the proper positions in the holding parts 51 to 55 or fall off from the holding parts 51 to 55 when the holder 50 is attached, Holder 50 by the elastic force of mechanism 31-35
The mounting efficiency of the holder 50 is improved without making the mounting of the holder 50 difficult. Further, at the time of maintenance of the lost motion mechanisms 31 to 35, since the lost motion mechanisms 31 to 35 can be extracted from the holding parts 51 to 55, it is not necessary to remove the holder 50 from the cylinder head 1, and the lost motion mechanism is not required. Maintenance work of 31 to 35 becomes extremely easy.

Fixing piece 42 of each lost motion mechanism 31-35
Are screw portions 51d to 55d of the holding portions 51 to 55.
By adjusting the position of the fixing piece 42 in the holding portions 51 to 55, the first, second, and third intake rocker arms 17 to 19, and third and third (4) Since the resilience of the exhaust rocker arms 23 and 24 can be adjusted, the holder of the lost motion mechanism 31 to 35 can be adjusted.
The adjustment of the resilience at the time of attachment to 50 and the adjustment of the resilience at the time of the change of the resilience due to the aging can be easily performed by adjusting the position of the fixed piece 42.

Further, since the fixing piece 42 is screwed and fixed to each of the holding portions 51 to 55, the coil spring 43 is rotated by the rotation of the fixing piece 42.
Of the coil spring 43
Can be adjusted steplessly and with high precision.

Further, the flange portion 42c is formed at each of the second open ends 51c to 51c.
By contacting with 55c, the fixing piece 4
Since the amount of screwing in 2 is regulated, it is possible to prevent the generation of an excessive elastic force of the coil spring 43 due to excessive screwing, and to stabilize the operation of each lost motion mechanism 31 to 35.

Since the outer periphery of the coil spring 43 is disposed in contact with the inner peripheral surfaces of the holding portions 51 to 55, the coil spring 43 is
Since the guides are guided along a to 55a, it is possible to prevent variations in the direction of action of the resilient force due to the fall of the coil spring 43, and in this regard, the operation of each of the lost motion mechanisms 31 to 35 can be stabilized.

In the valve operating chamber in which the valve operating device is disposed, other slides including the sliding portions between the cams 14, 15a, 15b, 16a, 16b of the valve operating device and the rocker arms 17-19, 21-24 are provided. The droplets of the lubricating oil supplied to the moving part are directly discharged from the oil supply hole 42f opened toward the space above the valve operating chamber or adhere to the fixed piece 42 to form a liquid flow, and through the oil supply hole 42f, The lubrication is supplied to the contact pieces 41 and the coil springs 43 of the motion mechanisms 31 to 35 to lubricate the sliding portions thereof. And this oil supply hole 42
Since f is provided on the fixing piece 42, there is no need to provide a structure for lubricating the holder 50 and the holding portions 51 to 55, and a lubricating oil supply path to the lost motion mechanism can be formed with a simple structure.

Further, when each of the lost motion mechanisms 31 to 35 is mounted on each of the holding portions 51 to 55 by the oil supply hole 42f,
It is also possible to visually check whether the contact piece 41 and the coil spring 43 have fallen off, and it is possible to perform a reliable assembly. Also,
The lost motion mechanisms 31 to 35 themselves can be reduced in weight.

The holder 50 has a concave portion 56 formed between the fourth and fifth holding portions 54 and 55, and further has a concave portion 56 between the fastening portions C3 and C5.
Since the concave portions 57 are formed between C6 and C8 and near the ends of the fastening portions C2 and C9 located at both ends, the weight of the holder 50 can be reduced, and the weight of the internal combustion engine can be reduced.

The first to fifth holding portions 51 to 55 are provided on the holder 50 so as to be inclined with respect to the connecting surface between the cylinder block and the cylinder head 1. , 55, the upper portions of the first and second exhaust rocker arms 21, 22 are inserted into the concave portion 56, thereby reducing the axial dimension of the cylinder of the internal combustion engine.
The internal combustion engine can be made compact.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration. In the above-described embodiment, each of the holding portions 51 to 55 is formed integrally with the holder 50. However, the holding portions 51 to 55 are formed of a cylindrical member separate from the holder, and are fixed to the holder. The fixed pieces 41 of the lost motion mechanisms 31 to 35 are screwed and fixed to screw portions formed on the inner peripheral surface of the tubular member, and the lost motion mechanisms 31 to 35 are attached to the inner holes of the tubular member. You can also.

In the above-described embodiment, the valve train is a valve train that performs cylinder deactivation. However, without performing cylinder deactivation, the intake valve and the exhaust valve are constantly opened and closed during engine operation, and engine operation is performed. The valve operating device may be provided with a mechanism for changing valve operating characteristics such as a lift amount according to a state.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a three-cylinder cylinder head forming one bank of an internal combustion engine to which the present invention is applied.

FIG. 2 is a plan view of a holder.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 1;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 4;

FIG. 8 is a partial sectional view of a lost motion mechanism.

[Explanation of symbols]

1 ... cylinder head, 2 ... combustion chamber, 3 ... intake port, 4
… Exhaust port, 5a, 5b… Intake valve, 6a, 6b… Exhaust valve, 7,
8 ... Stem guide, 9,10 ... Flange, 11,12 ... Valve spring, 13
… Cam shaft, 14… Intake cam, 15a, 15b… Exhaust stop cam, 1
6a, 16b ... exhaust cam, 17, 18, 19 ... intake rocker arm, 2
0 ... intake rocker arm shaft, 21, 22, 23, 24 ... exhaust rocker arm, 25 ... exhaust rocker arm shaft, 26, 27 ... tappet screw, 28 ... roller, 29, 30 ... roller, 31-35 ... lost motion mechanism, 39 ... Pipe, 41… Contact piece, 42… Fixed piece, 43
... Coil spring, 50 ... Holder, 51 ~ 55 ... Holding part, 51a, 52a
... bottomed hole, 53a ... through hole, 53c ... second open end, 56, 57 ... recess, 58 ... insertion hole, 59 ... notch, 60 ... piston, 61 ... connecting pin, 62 ... connecting piston, 63 ... return Springs, 64, 65, 66 ...
Guide hole, 67… Hydraulic chamber, 68… Communication path, 69… Hydraulic supply path,
70 ... piston, 71 ... connecting pin, 72 ... regulating piston, 73 ...
Return springs, 74, 75: guide hole, 76: hydraulic chamber, 77: communication path, 78: hydraulic supply path, 81: first rib, 82: second rib, 84
... third rib, 84 ... fourth rib, A1, A2, A3 ... cylinder, B1-B1
0: bolt, C1 to C10: fastening portion, D: connecting portion, L: axial direction of camshaft, M1, M2: connection switching mechanism P: flat surface.

 ──────────────────────────────────────────────────続 き Continuing on the front page F-term (reference) DA85 DA86 FA12 GA17 GA23 GA27

Claims (3)

[Claims] 1. A rocker arm which can be directly or indirectly swung by a cam provided on a camshaft to interlock with an engine valve, and a biasing means for urging the rocker arm toward the engine valve or the cam by resilient force. A valve gear for an internal combustion engine, comprising: a biasing member; and a holder provided with a holding portion that holds the biasing member by being attached to an open end of an engine body in which the rocker arm is swingably supported. The holding portion is provided with a through hole penetrating the holder toward the rocker arm, and the urging member is formed so as to be attachable to the through hole from an opening end on the side opposite to the rocker arm. Valve apparatus for an internal combustion engine. 2. The device according to claim 1, wherein the urging member has a fixing piece that can be adjusted in position for holding the urging member on the holding part, and the elastic force is adjusted by adjusting the position of the fixing piece. The valve train for an internal combustion engine according to claim 1, wherein: 3. The resilient member, wherein the urging member is mounted between the fixed piece and the contact piece to contact the rocker arm, and urges the contact piece toward the rocker arm. A resilient member having a force, wherein the fixed piece is provided with an oil supply hole that opens toward the upper space and supplies lubricating oil to the contact piece and the resilient member. The valve train for an internal combustion engine according to claim 2.