JPH0392573A - Cylinder head for internal combustion engine - Google Patents

Abstract

PURPOSE:To increase the lift quantity by forming head bolt insertion holes at the lower section of cam shaft bearing sections arranged between adjacent cylinders, and forming head bolt insertion holes on cam shaft bearing sections in a DOHC type internal combustion engine. CONSTITUTION:A cylinder head 1 has intake/exhaust valves (not shown in the figure) for each cylinder. Pivots (not shown in the figure) swayably supporting base ends of Y-shaped rocker arms 2 and 3 brought into contact with top sections of both valve shafts of two intake/exhaust valves are arranged on the outside of cam shaft bearing sections 14 and 15 swaying rocker arms 2 and 3. Cam shaft bearing sections 14 and 15 are arranged at ends of cylinders or between cylinders. Head bolt insertion holes 18 and 19 are formed at the lower section of cam shaft bearing sections 14 and 15, and head bolt insertion holes 16 and 17 are formed on cam shaft bearing sections 14 and 15.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a cylinder head for an internal combustion engine.

(Previous technology and its issues) Automotive engines are equipped with two intake valves or exhaust valves for each cylinder, and two camshafts are provided on the cylinder head corresponding to each intake valve and exhaust valve. DOHC type valve train structures are becoming widespread. As this kind of cylinder head,
For example, as disclosed in Japanese Patent Publication No. 1-2-2-4-6-4, an end-bipot type rocker arm is provided between the camshaft and the exhaust valve, and the intake and exhaust valve glue 7
There are some that secure a relatively large amount.

In this case, the pivot that swingably supports the base end of the rocker arm is provided inside the camshaft, and the boss for attaching the pivot is gathered around the ignition plug boss, and the oil passage for supplying oil to the pivot is arranged inside the camshaft. It was located in the center of the cylinder head. However, in J:Nlt construction, the intake valve rocker arm and the wandering valve rocker arm are lined up back to back, sandwiching the two spark plug bosses on the cylinder head. was restricted by the length of the rocker arm, which increased the slope of the Bentloo Type 7 combustion chamber wall, which caused a restriction on the Iso flash compression ratio.

In addition, with this structure, the distance between the intake valve camshaft and the exhaust valve camshaft provided on each rocker arm becomes large, resulting in an increase in the width of the cylinder head.

The present invention aims to solve these problems. (Means for Solving the Problems) In order to achieve the above object, the present invention provides a cylinder head for an internal combustion engine having two intake valves or exhaust valves for each cylinder. It is equipped with a Y-shaped rocker arm that contacts the tops of both valve shafts of the valve, a bipot that swingably supports the base of this cooker arm, and two camshafts 7F that swing the rocker arm. A head bolt that is placed outside of the shaft and has a camshaft bearing part that bears the camshaft placed at the end of the cylinder or between adjacent cylinder ends, and into which the head bolt is inserted below the camshaft bearing part. In addition to forming the hole, a hole for passing a heel bolt through the camshaft sludge receiving portion was also formed.

(Function) Based on the above W4 precept, by forming a head bolt through hole in the camshaft 7F bearing, a head bolt hole is formed below the camshaft bearing in the cylinder and Bolts and camshaft pongee receivers can be assembled easily or with the cylinder open.

By gathering the head bolt and camshaft pongee receiving part generously, and making the rocker arm that drives the two intake and exhaust valves into one Y-shape, the installation space for the pivot that supports the base end of the rocker arm is reduced to a cylinder. It is possible to secure it on the side of the head.

As a result, the swinging tips of the rocker arm for the suction valve and the rocker arm for the #5 valve face each other, and the pulp angle formed by the class valve pongee and the exhaust valve pongee is restricted by the length of the rocker arm. This allows the engine compression ratio, etc., to be set to a desired high value by reducing the angle of inclination of the wall surface of the combustion chamber of the BETRU 7 type. (Example) Hereinafter, an example of the present invention will be described based on the attached drawings. $1 As shown in the figure, the cylinder head 1 is DoHC type 4
It is provided in cylinder engines, and each cylinder has two intake valves and two exhaust valves. The cylinder head 1 is formed with a valve boss 11 in which a spark plug is attached to the center of each barrel, and four valve bosses 12=13 are formed around this plug boss 11 into which intake and exhaust valves are slidably inserted. be done.

In the cylinder head 1, bearing portions 14.15 for camshafts for intake valves and for wandering valves are formed at cylinder ends and between adjacent air cylinders.

As shown in FIG. 2, each camshaft pongee receiving part 14.
Head bolt holes 16 and 17 are formed in the head bolt holes 15, and head bolt holes 18+19 are formed below each of the head bolt holes 16 and 17. Therefore, the head bolts for fastening the cylinder head 1 to the cylinder block are arranged at predetermined intervals between each Mm, and sufficient sealing performance can be ensured via the socket.

Each camshaft bearing part 1 4, 1 5 and brag boss 11
A rib 20 is formed to connect the two in a beam shape to ensure a predetermined rigidity.

Y-shaped rocker arms 2 and 3 are provided on the cylinder head 1 to follow a cam to close an intake valve or an exhaust valve. In each of the rocker arms 2 and 3, two spearheads branching into a Y-shape abut on the top of each intake valve shaft or wandering valve shaft, and the base end thereof is swingably supported via a pivot.

A pivot that swingably supports the base end of each rocker arm 2, 3 is located outside of the camshaft in the plan view (Fig. 1), and the pivot is mounted on the sling head 1. Boss 28.29 into which hole 21.22 opens
are formed adjacent to the left and right side walls 23,24.

As shown in Figure ttS3 and Figure 4, the intake boat 4 has two ports connected to the cylinder head 1 that communicate with a common if.
It is a twin body type that gathers together inside, and each pivot mounting hole 21
．． 22 is located between the two intake boats 4 at a predetermined depth. It is formed. Each pivot mounting hole 2 1 . 2 A hydraulic lash adjuster is inserted into 2 to hold the pivot hydraulically. In the figure, 30 is a hole for removing the empty space when installing the Lash 7 Juster, 3h32 is a valve id, 33.34 is a valve seat, and 35 is a water jet. Oil passages 25 and 26 connecting the respective pivot mounting holes 21 and 22 are formed in a straight line in the cylinder head 1, and supply operating oil to each lash 7 juster.
It is designed to lubricate the sliding parts of the pivot. A cam bracket 6 is fastened to each camshaft 7F bearing i1 4.1 5 via two bolts 7, and a tubular oil supply pipe 8 is provided above each cam bracket 6. Oil is injected and supplied to each sliding part of the intake and exhaust valves.

In addition, as shown in FIG. LS and FIG. 6, cam brackets 36 and 37 for receiving the camshaft between the respective camshaft bearings 1 4 1 5 are integrally formed in a beam shape, and the cam brackets 36 and 37 are integrally formed in a beam shape. }An oil passage 38.39 may be formed at 36.37. In this case as well, oil is injected and supplied from the middle of the oil passages 38 and 39 to the sliding parts of the cam and the intake and exhaust valves through injection holes (not shown).

Next, the effect will be explained.

When assembling the cylinder head 1 to the cylinder block via head bolts, the head bolts and engineers are connected to each through hole 1 opened in each camshaft bearing part 1 4.1 5.
6. Insert from 17 and tighten the head bolt.

As a result, each head bolt hole 18.19 can be formed in the cylinder head 1 at a position below the camshaft bearing part 14, 15, and the head bolt and camshaft bearing part 14.15 can be formed. Both are collected at the cylinder end and between adjacent cylinders. In this way, the head bolt and camshaft bearing part 14.15 are assembled between the six cylinders and the YC cylinder, and the rocker arms 2 and 3, which open and close the two intake and exhaust valves, are formed into a Y shape and combined into one. By putting them together, it becomes possible to secure a space for the pivot mounting bosses 28 and 29 that support the base end of the rocker arm 2.3 on the side of the cylinder head outside the camshaft. As a result, the swinging tips of the intake valve rocker arm and the exhaust valve rocker arm each face each other, so the valve angle formed by the intake valve shaft and the wandering valve pongee is limited by the lengths of the rocker arms 2 and 3. The engine compression ratio can be set to a sufficiently high value by reducing the angle of inclination of the wall surface of the Bentloo type 7 combustion chamber. Additionally, the width of the cylinder head can be suppressed by making the gap between the intake valve camshaft 7F and the exhaust valve camshaft relatively small. (Effects of the Invention) As described above, according to the present invention, in a D O H C type internal combustion engine having two intake valves or two exhaust valves for each cylinder,
A camshaft bearing part is arranged between adjacent cylinders, and a head bolt hole is formed below the camshaft bearing part into which a head bolt is inserted.
A head bolt through hole is formed in the bearing part to allow the head bolt to pass through, and the end pivot type Y-shaped rocker arms are arranged so that the swinging tips of the Y-shaped rocker arms face each other on the suction side and the wandering side, resulting in an end pivot type rocker arm. Through this, it is possible to increase the amount of intake and exhaust valve glue 7F and reduce the valve angle to increase the engine compression ratio, improving engine performance and making the cylinder head more compact. .

[Brief explanation of drawings]

f:lrJ1 Figure is a plan view of a cylinder head showing an embodiment of the present invention, Figure 2 is a cross-sectional view taken along line A-A in the figure, M
Figure S3 is a cross-sectional view taken along the line B-B in the figure, and Figure 4 is a plan projection view of the intake boat and pivot mounting hole. younger brother 5
The figure is a plan view showing another embodiment! Figure 56 is a cross-sectional view taken along line A-A in the same figure. 1... Cylinder head, 2, 3... Rocker 7-m,
11...Brag boss, 12.13...Valve boss,
14, 15... Kamunya 7 to Tsumugi Uke 5, t6, 17...
・Head bolt through hole, 18.19... Head bolt hole, 21.22... Pivot mounting hole. Figure 4 Figure 2 Figure 3 5 35 j9 jkujj 4 j:) Figure 5 Figure 6

Claims (1)

[Claims] In the cylinder head of an internal combustion engine that has two intake valves or exhaust valves for each cylinder, a Y-shaped rocker arm that contacts the tops of both valve shafts of the two intake valves or exhaust valves, and a rocker arm that swings the base end of the rocker arm. A pivot supporting the rocker arm and two camshafts for swinging the rocker arm are provided.The pivot is located outside of the camshaft, and the camshaft bearing portion that supports the camshaft is located at the cylinder end or adjacent to the pivot. A head bolt hole is formed between the cylinders, and a head bolt is inserted below the camshaft bearing, and a head bolt hole is formed in the camshaft bearing to allow the head bolt to pass through. cylinder head of an internal combustion engine.