JPH109044A - Valve system installing structure of cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the generation of a thin wall or a cutting of the annulus ring of a lifter guide owing to the seat surface processing of a head bolt, while suppressing the increase of the valve holding angle and the height of a cam shaft. SOLUTION: Installing parts 33 and 43 are provided to suction side and exhaust side lifter guide cam carriers 30 and 40 which are separated from a cylinder head 1, and they are fixed on the upper surface of the central rising part 5 of the cylinder head 1, and the upper surface of side walls 3 and 4 through an inner holder 20 and an outer holder. Since the cam carriers 30 and 40 are separated from the cylinder head 1, the annulus ring of the lifter guide is never cut off, and a head bolt can be provided at the lower side. And since the lifter guide cam carriers can be lowered obliquely along a valve shaft, and valve springs 9 can be fitted in valve lifters 13 and 14, the position of the cam shafts can be made lower. And since they are connected at the upper surface of the head, the interference of bolts and the like can be avoided easily, and the distance between cam shafts 15 and 16 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mounting structure of a valve mechanism in a cylinder head of a reciprocating internal combustion engine.

[0002]

2. Description of the Related Art In a valve operating mechanism of a reciprocating internal combustion engine, a rocker arm type follower and a bucket type follower, commonly called a valve lifter, have conventionally been used as mechanisms for converting the rotational movement of a camshaft into the reciprocating movement of an intake / exhaust valve. Many are used. By the way, especially in the case of an automobile engine, a multi-valve type in which an increase in the total valve area and a central arrangement of a spark plug are compatible is often adopted in order to improve output and facilitate exhaust gas purification. Are arranged as a V-shaped valve arrangement.
For this reason, the number of followers of the valve operating mechanism becomes large, and among the followers, a low-cost valve lifter tends to be selected.

However, while the rocker arm type follower has an effect of amplifying the valve lift, the valve lifter does not have such an amplifying effect. Therefore, in order to obtain a predetermined lift amount, it is necessary to use a large-diameter valve lifter. is there. Therefore, when the distance between adjacent cylinder bores is small, as shown in FIG. 7, the distance between the head bolt for attaching the cylinder head 80 to the cylinder block and the valve lifter is shortened, and the circle of the lifter guide 81 for guiding the valve lifter is reduced. There is a problem in that the ring portion 82 is thinned or cut by hatch surface processing 83 in the hatched portion. In the figure, reference numeral 84 denotes a cylinder bore.

[0004]

One of the conventional measures to avoid such a problem is to increase the included angle of the valve in the V-type valve arrangement, position the valve lifter outside the head bolt in the cylinder width direction, and lift the lifter. An object of the present invention is to prevent the annular portion of the guide from overlapping with the seat surface processed portion of the head bolt. However, if the included angle of the valve is increased, the shape of the combustion chamber becomes large, and the intake port also becomes a curved shape having a large intake resistance. A large surface area of the combustion chamber is disadvantageous for reducing heat loss and unburned HC.

Therefore, as another measure, as shown in FIG.
Like the MW and M20 engines, the lifter guide 86 is separated from the cylinder head 85 so as to be separated from the cylinder head 85 so that the annular portion of the lifter guide is not thinned or cut by the seating of the head bolt. Can be In this system, the lifter guide is provided separately for each of the left and right exhaust valves and intake valves, and the lifter guide 86 and the cam carrier 8 are separated.
7 can be integrally inserted and assembled in each valve axis direction. However, at the same time, the mounting bolt 89 of the cam carrier sandwiching the camshaft 88 also sandwiches the head of the head bolt, so that the valve included angle cannot be made very small.

Therefore, for example, Mcl shown in FIG.
ren, like the S70 / 2 type engine, the lifter guide 91 is separated from the cylinder head 90 with the suction and discharge integrated,
In some cases, this is mounted on a cylinder head. Also in this case, there is an advantage that the annular portion of the lifter guide is not thinned or cut by the seat surface processing of the head bolt,
Since the lifter guide 91 is integral with the suction and discharge, insertion and assembly in accordance with the valve axis direction becomes impossible, and the valve spring 9
2 cannot enter the lifter guide hole. Therefore, there is a disadvantage that the valve lifter 93 does not fit with the valve spring 92, and the valve shaft end is extended so that the position of the camshaft 94 is increased, so that the valve lifter 93 is mounted.

Accordingly, in view of the above-mentioned conventional problems, the present invention suppresses an increase in the included angle of the valve and does not increase the position of the camshaft while avoiding the thinning and cutting of the annular portion of the lifter guide. It is an object of the present invention to provide a cylinder head valve mechanism mounting structure as described above.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a cylinder for a reciprocating internal combustion engine which includes a camshaft for an intake valve and a camshaft for an exhaust valve, and drives the intake valve and the exhaust valve via respective valve lifters. In a mounting structure of a valve operating mechanism in a head, an intake-side lifter guide / cam carrier including a cam carrier section supporting a cam shaft for an intake valve and a lifter guide section supporting a valve lifter, and a cam shaft for an exhaust valve are supported. An exhaust-side lifter guide / cam carrier having a cam carrier portion and a lifter guide portion for supporting the valve lifter is formed separately from the cylinder head, and the intake-side lifter guide / cam carrier and the exhaust-side lifter guide / cam carrier are respectively provided. Connected to the upper surface of the cylinder head on the upper surface It was a shall.

The above-mentioned intake side and exhaust side lifter guides
The lifter guide portion and the cam carrier portion of the cam carrier are arranged at different positions in the camshaft axial direction,
The lifter guide is provided with a mounting portion extending upward across the camshaft, and the upper surface of the mounting portion can be connected to the upper surface of the cylinder head by a connecting member. More specifically, the cylinder head has a central rising portion corresponding to a substantially central position of the combustion chamber, and the connecting member includes an inner holder that connects the inner mounting portion to the upper surface of the central rising portion, and an outer mounting portion. And an outer holder connected to the upper surface of the side wall of the cylinder head.

[0010] The intake side and exhaust side lifter guides
The cam carrier portion of the cam carrier can be connected to the upper surface of the cylinder head via a camshaft bracket attached to the upper surface of the cam carrier portion. At this time, it is preferable that the camshaft bracket is connected to the upper surface of the boss provided on the center side of the cylinder head and the upper surface of the side wall of the cylinder head.

Further, the connection between the connecting member and the upper surface of the cylinder head, and the connection between the camshaft bracket and the upper surface of the cylinder head are desirably performed by connection using vertically arranged bolts. Further, a head bolt for connecting the cylinder head to the cylinder block can be arranged below the lifter guide / cam carrier on the intake side and the exhaust side.

[0012]

Since the lifter guide and cam carrier on the intake side and the exhaust side are formed separately from the cylinder head, the annular portion of the lifter guide portion is made thin by machining the seat surface of the head bolt of the cylinder head. It will not be cut or disconnected. Moreover, since the connection to the cylinder head is made on the upper surface of the cylinder head, the intake-side and exhaust-side lifter guide / cam carriers can be set closer to the center, for example, by avoiding interference between the mounting bolts and other members. Thus, the distance between the camshafts can be reduced, and the included angle of the valve can be easily reduced. Since the intake-side and exhaust-side lifter guides / cam carriers are separate from each other, they can be inserted and assembled in the valve axis direction respectively, and the valve spring can be located in the valve lifter to lower the camshaft position.

At this time, the lifter guide portion is inclined, but can be easily connected to the upper surface of the cylinder head by extending the mounting portion upward. In particular, a highly rigid connection can be obtained by connecting, via an inner holder and an outer holder, the upper surface of the central rising portion of the cylinder head where the passage for attaching and detaching a spark plug is formed, and the upper surface of the cylinder head side wall.

Further, by connecting the lifter guide / cam carrier to the upper surface of the cylinder head via a cam shaft bracket supporting the cam shaft in cooperation with the cam carrier portion, the lifter guide / cam carrier is connected to the cylinder head. Fixation becomes more reliable. By using vertically arranged bolts for connection, interference with other members can be easily avoided, and the valve included angle can be set with a large degree of freedom. Since the lifter guide / cam carrier is mounted on the upper surface of the cylinder head, there is room for space below the lifter guide / cam carrier. By arranging the head bolts here, the lifter guide / cam carrier and the head bolts are provided. Interference with the device is completely avoided.

[0015]

Embodiments of the present invention will be described below with reference to examples. FIG. 1 is a cross-sectional view showing the embodiment, and FIG. 2 is a top view showing the head cover removed. FIG. 1 corresponds to a cross section taken along the line AA in FIG. FIG.
4 shows a cross section taken along the line BB in FIG. 2, and FIG. 4 shows a cross section taken along the line CC in FIG. FIG. 5 shows the arrangement of the lifter guide and cam carrier as viewed in the direction of the arrow DD in FIG.
FIG. 6 shows an EE section in FIG. 4. The cylinder head 1 includes a bottom surface 2 joined to an upper surface of a cylinder block (not shown), left and right side walls 3 and 4, and a central rising portion 5. The upper surfaces of the side walls 3, 4 and the central rising portion 5 are flush with each other. I have.

As shown in FIG. 1 in particular, the cylinder head 1 is provided with valve guides 6, 6 for slidably guiding the valve shafts of an intake valve 7 and an exhaust valve 8, and the valve guides 6, 6 are provided with valve guides. At the included angle α, they extend on opposite sides of the central rising portion 5. A valve spring 9 is mounted on the valve shafts of the intake valve 7 and the exhaust valve 8, and valve lifters 13 and 14 are respectively provided at the tip portions of the valve shafts.
, And each valve lifter is in contact with the cams of the camshafts 15 and 16 having a twin cam configuration.

On the upper surface of the center rising portion 5 of the cylinder head 1, an inner holder 20 extending to the left and right of the center rising portion 5 is fixed by studs and nuts 70. As shown in FIG. 3, the center rising portion 5 has a bottomed hole 25 extending in the vertical direction substantially toward the center of the combustion chamber 12, and an ignition plug 26 is attached to the bottom. In FIG. 3, the valve spring 9 is not shown. As shown in FIGS. 2 and 5, the studs and nuts 70 are located before and after the bottomed hole 25 for the ignition plug (in the direction parallel to the camshafts 15 and 16), and at the center of the inner holder 20. A hole 21 for attaching and detaching a spark plug is formed.

Intake side lifter guide cam carrier 30
Is a lifter guide section 31 for guiding the valve lifter 13
And a cam carrier 32 for supporting the camshaft 15. The intake-side lifter guide / cam carrier 30 is provided with mounting portions 33 and 34 extending upward with the camshaft 15 interposed between the lifter guide portion 31 and the lifter guide portion 31. The exhaust-side lifter guide / cam carrier 40 has the same configuration, and includes a lifter guide section 41 and a cam carrier section 42, and mounting sections 43 and 44 extending upward with the cam shaft 16 interposed therebetween are provided on the lifter guide section 41. Each inner mounting part 3
The reference numerals 3 and 43 are fixed with stud bolts and nuts 71 with their upper surfaces abutting against the lower surfaces of the inner holders 20 projecting to the left and right of the central rising portion 5.

Outer holders 37, 37 are fixed to the upper surfaces of the cylinder head side walls 3, 4 at projecting portions 35, 45 by stud bolts and nuts 72. Then, as shown in FIG. 3 in particular, the lifter guide portions 31, 4 are provided on the lower surfaces of the outer holders 37, 37.
The upper surfaces of the outer mounting portions 34 and 44 are respectively abutted, and are fixed by stud bolts and nuts 73. Thus, each lifter guide cam carrier 30,
Reference numeral 40 is fixed to the cylinder head 1 both inside and outside the lifter guide portions 31 and 41.

The cam carrier 32 of the intake side lifter guide cam carrier 30 has a semicircular bearing recess,
The upper surface 51 is flush with the upper surfaces of the side wall 3 and the center rising portion 5. A camshaft bracket 47 having a semicircular bearing recess is fixed to the upper surface 51 by studs and nuts 74.
I support. Exhaust-side lifter guide / cam carrier 4
Similarly, a camshaft bracket 47 is attached and fixed to the 0 cam carrier portion 42 with studs and nuts 74.

On the other hand, as shown in FIG. 4, the cylinder head 1 is further provided with bosses 60 adjacent to the front and rear of the center rising portion 5, the upper surfaces of which are in contact with the upper surfaces of the side walls 3, 4 and the center rising portion 5. It is M level. The camshaft bracket 47 extends between the upper surface of the boss 60 and the upper surfaces of the cylinder head side walls 3 and 4 at the overhanging portions 38 and 48, and is fixed by stud bolts and nuts 75. The studs and the bolts of the nuts 70 to 75 are shown in FIGS.
Are all arranged vertically.

As shown in FIGS. 4 and 6, between the side walls 3 and 4 of the cylinder head 1 and the center rising portion 5, suction and exhaust are provided below the intake and exhaust side lifter guide / cam carriers 30 and 40. The hole 62 penetrating to the bottom surface 2 avoiding the spring seat portion 66 of the valve spring 9 of the valve
The head bolt 64 couples the cylinder head 1 to the cylinder block through the hole 62. A head cover 10 is mounted on the upper surface of the cylinder head 1 so as to cover the valve mechanism configured as described above.

The valve operating mechanism is assembled in the following manner. (1) First, a valve spring 9 is attached to the cylinder head 1.
And an intake valve 7 together with a retainer and a cotter (not shown).
And the exhaust valve 8 is attached. (2) Next, the intake-side and exhaust-side lifter guide / cam carriers 30 and 40 are lowered obliquely along the valve axes of the corresponding intake valves 7 and exhaust valves 8, respectively, and the valve lifters 13 and 14 are moved to the respective lifter guide portions. 31 and 41, and the height of the upper surface of the mounting portion 33, 34, 43, 44 is adjusted to the upper surface of the cylinder head (the center rising portion 5 and the side walls 3, 4).
(Upper surface). Then, it is fixed to the upper surface of the cylinder head with studs and nuts via the inner holder 20 and the outer holder 37.

(3) Then, the camshaft 1 is attached to the cam carrier portions 32 and 42 of each lifter guide / cam carrier.
5 and 16, are mounted on the lifter guide / cam carriers 30 and 40 with the camshaft brackets 47 and fixed with studs and nuts, and both ends of the camshaft bracket 47 are studded with studs and nuts on the upper surface of the cylinder head (the boss 60 and the side wall). 3 and 4).

In this embodiment, the lifter guide / cam carriers 30 and 40 are separated from the cylinder head 1 and are separated from the cylinder head side walls 3 and 4 and the center rising portion 5 on the upper surface of the cylinder head. Since the head bolts 64 are located below these components so that they are attached, the annular portion of the lifter guide portion is not cut. Similarly, lifter guide cam carrier 30, 40
Is mounted on the upper surface of the cylinder head, so that the assembling work is also easy. Each lifter guide / cam carrier is connected and fixed to the cylinder head 1 on both the inside and outside of the lifter guide portions 31, 41 and the cam carrier portions 32, 42, so that the coupling rigidity is high.

Since the lifter guide and cam carrier are mounted by vertically arranged studs, interference with other bolts and nuts and other members can be easily avoided, and both camshafts 15 and 16 of the intake valve and the exhaust valve can be used.
The distance between them can be reduced. This makes it possible to reduce the included angle of the valve as compared with a conventional example in which the lifter guide and the camshaft carrier are attached by bolts inclined in the valve axis direction at the intermediate position of the cylinder head.

The lifter guide cam carrier 30,
Since the intake valve side and the exhaust valve side are separated and separated from each other, insertion assembly in the valve axis direction is possible,
Thereby, the valve spring 9 is connected to the valve lifter 13,
14 so that the camshaft 1
The positions of 5 and 16 can also be suppressed low.

In the embodiment, the attachment of each member is performed by using the stud bolt and the nut. However, the present invention is not limited to this, and the nut may be abolished depending on the position, depending on the part. Also,
Although the embodiment has been described with reference to an example of four valves per cylinder, the present invention is equally applicable to an engine having a larger number of valves.

[0029]

As described above, according to the present invention, in a valve operating mechanism of a cylinder head having a camshaft for an intake valve and an exhaust valve, a lifter guide / cam carrier on an intake side and an exhaust side are separated from a cylinder head, respectively. Are formed separately and connected on the upper surface of the cylinder head, so that the annular portion of the lifter guide portion is not thinned or cut by machining the seat surface of the head bolt of the cylinder head. The distance between the shafts can be reduced, and the included angle of the valve can be easily reduced. And
Since the intake-side and exhaust-side lifter guides / cam carriers are separate from each other, they can be inserted and assembled in the valve axis direction, respectively, and the camshaft position can be lowered by fitting a valve spring in the valve lifter.

In particular, the mounting portion extends from the lifter guide portion of the lifter guide / cam carrier, and is connected to the upper surface of the cylinder head, particularly the upper surface of the center rising portion, and the upper surface of the cylinder head side wall via the inner holder and the outer holder. High binding is obtained. further,
By connecting the cam carrier portion of the lifter guide / cam carrier to the upper surface of the cylinder head via the cam shaft bracket, the lifter guide / cam carrier is more securely fixed to the cylinder head.

The use of vertically arranged bolts for the connection has the advantage that interference with other members can be easily avoided, and that the valve angle can be set with a large degree of freedom. Since the lifter guide / cam carrier is mounted on the upper surface of the cylinder head, there is room for space below the lifter guide / cam carrier. By arranging the head bolts here, the lifter guide / cam carrier and the head bolts are provided. Interference with the device is completely avoided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a top view of the embodiment with the head cover removed.

FIG. 3 is a sectional view taken along the line BB in FIG. 2;

FIG. 4 is a sectional view taken along the line CC in FIG. 2;

FIG. 5 is a view taken in the direction of the arrow DD in FIG. 1;

FIG. 6 is a view taken in the direction of arrows EE in FIG. 4;

FIG. 7 is a diagram showing a conventional example.

FIG. 8 is a diagram showing another conventional example.

FIG. 9 is a diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Bottom surface 3, 4 Side wall 5 Central rising part 7 Intake valve 8 Exhaust valve 6 Valve guide 9 Valve spring 10 Head cover 13, 14 Valve lifter 15, 16 Camshaft 20 Inner holder 25 Bottom hole 30 Intake side lifter guide / cam carrier 31 Lifter guide section 32 Cam carrier section 33, 34 Mounting section 35, 38, 45, 48 Overhang section 37 Outer holder 40 Exhaust side lifter guide / cam carrier 41 Lifter guide section 42 Cam carrier section 43, 44 Mounting section 47 Cam shaft bracket 60 Boss 62 Hole 64 Head bolt 66 Spring seat part 70-75 Stud bolt and nut

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Reference number in the agency FI Technical display F02B 77/00 F02B 77/00 N

Claims (7)

[Claims] 1. A valve train mechanism for a cylinder head of a reciprocating internal combustion engine that includes a camshaft for an intake valve and a camshaft for an exhaust valve, and drives the intake valve and the exhaust valve via a valve lifter, respectively. An intake-side lifter guide / cam carrier including a cam carrier section supporting a cam shaft and a lifter guide section supporting a valve lifter, and a cam carrier section supporting a cam shaft for an exhaust valve and a lifter guide section supporting a valve lifter. The exhaust-side lifter guide / cam carrier is formed separately from the cylinder head, and the intake-side lifter guide / cam carrier and the exhaust-side lifter guide / cam carrier are respectively connected to the upper surface of the cylinder head at their upper surfaces. Characteristic cylinder valve mechanism Mounting structure. 2. The intake-side and exhaust-side lifter guides
The lifter guide portion and the cam carrier portion of the cam carrier are arranged at different positions in the camshaft axial direction,
2. The cylinder head according to claim 1, wherein the lifter guide has a mounting portion extending upward across the camshaft, and an upper surface of the mounting portion is connected to an upper surface of the cylinder head by a connecting member. Valve mechanism mounting structure. 3. The cylinder head has a central rising portion corresponding to a substantially central position of a combustion chamber, wherein the connection member connects an inner mounting portion to an upper surface of the central rising portion, and an outer mounting portion. 3. The structure for mounting a valve operating mechanism for a cylinder head according to claim 2, further comprising an outer holder connecting the portion to an upper surface of a side wall of the cylinder head. 4. The intake-side and exhaust-side lifter guides
4. The valve train according to claim 2, wherein the cam carrier portion of the cam carrier is connected to the upper surface of the cylinder head via a cam shaft bracket attached to the upper surface of the cam carrier portion. Mechanism mounting structure. 5. The cylinder according to claim 4, wherein the camshaft bracket is connected to an upper surface of a boss provided on a center side of the cylinder head and an upper surface of a side wall of the cylinder head. Head valve mechanism mounting structure. 6. The connection between the connecting member and the upper surface of the cylinder head and the connection between the camshaft bracket and the upper surface of the cylinder head are each performed by a connection using vertically arranged bolts. Claim 4
6. The valve head mounting structure for a cylinder head according to claim 5. 7. A head bolt for connecting the cylinder head to a cylinder block is disposed below the intake-side and exhaust-side lifter guide / cam carriers. 7. A valve head mounting structure for a cylinder head according to claim 5.