JPH06146822A - Engine cylinder head structure - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a cylinder head structure of an engine that can improve the assemblability of the engine and reduce the cost while increasing the diameter of the lifter. A cam carrier 10 integrally including at least a lifter guide portion 11 and a cam shaft journal 12 is formed separately from the cylinder head body 1A.
0 is tightened and integrated with the cylinder head body 1A, and a cylinder head cover mounting portion is provided on the cylinder head body 1A. According to the present invention, since the cam carrier 10 can be assembled alone to the cylinder head body 1A after the cylinder head body 1A is assembled to the cylinder block, the assemblability of the engine is enhanced. or,
Since the cylinder head cover mounting portion is provided on the cylinder head main body 1A, the number of sealing portions does not increase and the cost can be avoided even though the cam carrier 10 is formed separately from the cylinder head 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cylinder head structure.

[0002]

2. Description of the Related Art Even in an engine having a plurality of intake and exhaust valves, for example, a five-valve engine having three intake valves and two exhaust valves, it is desirable to increase the lifter diameter in order to increase the lift amount of the intake valve. It is rare.

However, if an attempt is made to increase the diameter of the lifter, the lifter guide portion may cover the upper portion of the cylinder head bolt, which may cause a problem that the cylinder head bolt cannot be assembled. For this reason, conventionally, a cam carrier integrally having a cam shaft journal and a lifter guide portion has been constructed separately from the cylinder head main body (for example, Japanese Patent Laid-Open No. Sho 60).
-216011).

[0004]

However, in the conventional structure, since the mounting portions for the cylinder head and the cylinder head cover are provided on the upper and lower surfaces of the cam carrier, respectively, there is a problem that the number of sealing points increases and the cost increases. there were.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the engine assemblability and reduce the cost of the engine while increasing the diameter of the lifter. To provide a head structure.

[0006]

In order to achieve the above object, the present invention comprises a cam carrier integrally including at least a cam shaft journal and a lifter guide portion, which is separate from a cylinder head body, and the cam carrier is a cylinder. It is characterized in that it is integrally tightened with the head main body and that the cylinder head main body is provided with a cylinder head cover mounting portion.

[0007]

According to the present invention, since the cam carrier is formed separately from the cylinder head, the cam carrier is fastened to the cylinder head body after the cylinder head body is fastened to the cylinder block with the head fastening bolts. The engine can be assembled easily.

Further, since the cylinder head cover mounting portion is provided on the cylinder head main body, the seal portion does not increase and the cost can be prevented from increasing although the cam carrier is formed separately from the cylinder head.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partial plan view of a cylinder head according to a first embodiment of the present invention, and FIGS. 2, 3 and 4 are respectively FIG.
3 is a cross-sectional view taken along line AA, line BB, and line CC of FIG.

The cylinder head 1 according to this embodiment is fastened by a plurality of head fastening bolts 2 to the upper portion of a cylinder block body (not shown) of a multi-cylinder DOHC 5 valve engine, and the intake side of the bolt is tightened. 3 for each cylinder
One intake passage 3 and two exhaust passages 4 are formed on the exhaust side. The intake passages 3 and the exhaust passages 4 open into the combustion chamber 5, and their respective opening portions (suction, suction,
The exhaust port) is opened and closed by an intake valve 6 and an exhaust valve 7 at appropriate timing. In the cylinder head 1,
A plug hole 8 is formed for each cylinder in a substantially central portion in the width direction, and an ignition plug 9 is fitted and screwed into each plug hole 8.

By the way, in this embodiment, a cam carrier 10 which is formed separately from the cylinder head body 1A is attached to the intake side of the cylinder head 1. The cam carrier 10 includes three lifter guide portions 1 which are arranged in parallel for each cylinder so as to correspond to the three intake valves 6.
1 and a cam shaft journal 12 provided so as to sandwich the three lifter guide portions 11 from both sides between the cylinders.

An intake side cam shaft 13 is rotatably supported by a cam shaft journal 12 provided on the cam carrier 10, and each cam shaft 13 has a corresponding cam shaft journal 12.
It is held by a cam cap 14 attached to the.
The cam shaft 13 is integrally formed with three cams 13a for each cylinder.

Thus, the cam carrier 10 and the cam cap 14 are integrally fastened to the cylinder head body 1A by the cap bolts 15 inserted through them.
A tool hole 12a, through which a tool (not shown) is to be inserted, is formed at a position where the head tightening bolt 2 of each camshaft journal 12 is arranged.

By the way, as shown in FIGS. 3 and 4, each intake valve 6 is slidably inserted into a valve guide 16 fixed to the cylinder head body 1A.
Is urged toward the closing side by a valve spring 18 that is compressed between the cylinder head body 1A and the retainer 17. A valve lifter 19 is in contact with the upper portion of the intake valve 6, and the valve lifter 19 is slidably fitted in the lifter guide portion 11 of the cam carrier 10, the upper surface of which is the cam. It is in contact with a cam 13a formed on the shaft 13.

Thus, the camshaft 13 is part of the engine power.
Is rotationally driven, the intake valve 6 is driven by the cam 13a that rotates integrally with the cam shaft 13, and the intake port is opened and closed at an appropriate timing.

A cylinder head cover mounting portion 1a is formed on the upper surface of the cylinder head 1, and the cylinder head cover 20 is attached to the cylinder head cover mounting portion 1a.

On the other hand, on the exhaust side, as shown in FIG. 1, two lifter guide portions 21 are integrally formed on the cylinder head body 1A itself, and both lifter guides 2 are formed.
1, the cam shaft journal 22 is formed. or,
On the exhaust side, the head tightening bolt 2 is arranged between the lifter guide portions 21 of the adjacent cylinders.

Thus, the camshaft 2 on the exhaust side as well as the intake side
3 is rotatably supported by a cam shaft journal 22, and the cam shaft 23 is pressed by a cam cap 25 attached to each cam shaft journal 22 by a cap bolt 24. Two cams 23 a are integrally formed on the cam shaft 23 for each cylinder.

Further, as shown in FIG. 4, each exhaust valve 7 is a valve guide 26 fixed to the cylinder head body 1A.
It is slidably inserted in the cylinder head 1A.
The valve spring 28 is compressed between the retainer 27 and the retainer 27 and is urged toward the closing side. A valve lifter 29 is in contact with the upper portion of the exhaust valve 7, and the valve lifter 29 is slidably fitted in the lifter guide portion 21, the upper surface of which is formed on the cam shaft 23. It is in contact with the cam 23a.

When the camshaft 23 on the exhaust side is rotationally driven by a part of engine power, the exhaust valve 7 is driven by the cam 23a which rotates integrally with the camshaft 23, and the exhaust port is appropriately opened. It is opened and closed at various times.

Now, the procedure for assembling the cylinder head 1 will be described.

That is, first, the valve operating system components except the valve lifters 19 and 29 are assembled to the cylinder head main body 1A, the cylinder head main body 1A is covered on the upper surface of a cylinder block (not shown), and the cylinder head main body 1A is tightened by the head tightening bolts 2. Assemble 1A to the cylinder block. At this time, since the cam carrier 10 is not assembled to the cylinder head main body 1A, the heads of all the head tightening bolts 2 are exposed, and the tightening work of these is extremely easy using a tool, and the engine is assembled. The stickiness is enhanced.

Next, the cam carrier 10 and the cam cap 1
4 is assembled to the cylinder head main body 1A with the cap bolt 15 and the valve lifter 19 is fitted into each lifter guide portion 11 of the cam carrier 10 to complete the assembly of the cylinder head 1.

By the way, especially when the inclination angle of the intake valve 6 is large, the cam carrier 10 is connected to the cylinder head body 1A.
Since the lifter guide portion 11 interferes with the retainer 17 and the valve spring 18 during the assembling, the above assembling becomes impossible, but in such a case, the assembling is performed by the following procedure.

That is, with the head tightening bolt 2 inserted in the cylinder head body 1A in advance, the cam carrier 10 and the cam cap 14 are assembled to the cylinder head 1A with the cap bolts 15, and the valve operating system parts including the valve lifter 19 are attached to the cylinder. After assembling into the head body 1A, cover the entire cylinder head 1 on the upper surface of a cylinder block (not shown),
Tighten the head tightening bolt 2 to assemble the entire cylinder head 1 to the cylinder block. At this time, the tightening of the head tightening bolt 2 on the intake side is performed by the cam carrier 10
Hole 12 for the tool formed in the camshaft journal 12 of
It is performed by inserting a tool from a.

Thus, according to this embodiment, the head tightening bolt 2, the cam shaft journal 12 and the lifter guide 11 are provided.
Since the positional relationship where and overlap is allowed, D
The camshaft journal 12 for supporting the camshaft 13 can be secured even if the gap between the valve lifters 19 on the intake side becomes small in order to reduce the size and size of the OHC engine.

Further, since the cylinder head cover mounting portion 1a is provided on the cylinder head body 1A, the cam carrier 10
Although the cylinder head 1 and the cylinder head 1 are formed separately, the number of sealing points does not increase, and the cost increase can be avoided.

Next, a second embodiment of the present invention will be described with reference to FIGS.
It will be described based on. 5 is a partial plan view of the cylinder head according to the second embodiment, and FIGS. 6, 7, and 8 are sectional views taken along the lines D-D, E-E, and F-F of FIG. 5, respectively. In these figures, the same elements as those shown in the first embodiment are designated by the same reference numerals (the same applies to the following embodiments).

In the present embodiment, the cam carrier 10 is integrated with the ignition plug boss portion 30.
In addition to the cap bolt 15, another tightening bolt 31 (see FIG.
(See also) can be assembled to the cylinder head body 1A.

9 to 12 show a third embodiment of the present invention. 9 is a partial plan view of the cylinder head according to the third embodiment, and FIGS. 10, 11, and 12 are GG of FIG.
It is a line, a HH line, and an II line sectional view.

In the third embodiment, the cam carrier 10 is provided with a lifter guide portion 11 on the intake side and a cam shaft journal 12.
In addition to the spark plug boss portion 30, the exhaust side lifter guide portion 21 and the cam shaft journal 22 are integrally configured, and the cam carrier 10 is assembled to the cylinder head body 1A by the cap bolt 15 and the tightening bolt 31. To be In the cam carrier 10 according to this embodiment, the intake side lifter guide portion 11 and the cam shaft journal 12 are connected to the exhaust side lifter guide portion 21 and the cam shaft journal 22 by the ignition plug boss portion 30.
You may make it connect both by another member.

Further, FIGS. 13 to 16 show a fourth embodiment of the present invention. 13 is a partial plan view of the cylinder head according to the fourth embodiment, and FIGS. 14, 15, and 16 are sectional views taken along the line JJ, KK, and LL of FIG. 13, respectively.

In this embodiment, the cam carrier 10 is integrally formed by connecting the intake side lifter guide portion 11, the cam shaft journal 12, the exhaust side lifter guide portion 21 and the cam shaft journal 22 with ribs. There is.

Next, a fifth embodiment of the present invention is shown in FIGS. 17 is a partial plan view of a cylinder head according to the fifth embodiment, and FIGS. 18, 19, and 20 are sectional views taken along line MM, NN, and PP of FIG. 17, respectively.

In this embodiment, as in the first embodiment, the cam carrier 10 is integrally provided with the intake side lifter guide portion 11 and the cam shaft journal 12, but the cam carrier 10 has one cap. The bolt 15 is fastened together with the cam cap 14 to the cylinder head body 1A, and is also fastened to the cylinder head body 1A by the fastening bolts 32 arranged between the cam shaft journals 12 (see FIG. 17). If the tightening bolt 32 is arranged at this position (solid line position in FIG. 17), the diameter of the sand removal hole 33 opening on the upper surface of the cylinder head body 1A can be made larger than that at the chain line position. .

On the other hand, when the tightening bolt is arranged at the chain line position in FIG. 17 (on the side of the camshaft journal 12), the tightening bolt 32
Since the cap bolt 15 on the side of can be arranged closer to the center tip side of the cam shaft 13, the surface pressure of the mating surfaces of the cam carrier 10 and the cam cap 14 can be increased,
Even if a large reaction force is applied to the cam cap 14 from the cam shaft 13, fretting or the like does not occur on the mating surface.

Here, the oil supply structure for the intake side camshaft 13 is shown in FIGS. 21 is a partial plan view of the cylinder head, and FIGS. 22 and 23 are Q- of FIG. 21, respectively.
It is a Q line and a RR line sectional view.

The cam carrier 10 has an oil passage 3 which is long in the cylinder arrangement direction (direction perpendicular to the plane of the paper in FIGS. 22 and 23).
4 is formed, and this oil passage 34 is connected to an oil passage 35 formed in the cylinder head body 1A. Each camshaft journal 12 is formed with an oil passage 36 that branches from the oil passage 34 and rises upward, and the oil supplied from the oil passage 35 flows through the oil passages 34, 36 in the direction of the arrow in FIG. Is supplied to the journal portion of the cam shaft 13 and used for lubrication and cooling of the cam shaft 13.

[0040]

As is apparent from the above description, according to the present invention, the cam carrier integrally including at least the cam shaft journal and the lifter guide portion is formed separately from the cylinder head body, and the cam carrier is formed in the cylinder. Since the cylinder head cover mounting portion is provided on the cylinder head body while integrally tightening with the head body, it is possible to improve the engine assemblability and reduce the cost while increasing the diameter of the lifter. can get.

[Brief description of drawings]

FIG. 1 is a partial plan view of a cylinder head according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

4 is a cross-sectional view taken along the line CC of FIG.

FIG. 5 is a partial plan view of a cylinder head according to a second embodiment of the present invention.

6 is a cross-sectional view taken along the line DD of FIG.

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

8 is a sectional view taken along line FF of FIG.

FIG. 9 is a partial plan view of a cylinder head according to a third embodiment of the present invention.

10 is a cross-sectional view taken along the line GG of FIG.

11 is a cross-sectional view taken along line HH of FIG.

12 is a cross-sectional view taken along line I-I of FIG.

FIG. 13 is a partial plan view of a cylinder head according to a fourth embodiment of the present invention.

14 is a sectional view taken along line JJ of FIG.

15 is a sectional view taken along line KK of FIG.

16 is a sectional view taken along line LL in FIG.

FIG. 17 is a partial plan view of a cylinder head according to a fifth embodiment of the present invention.

18 is a sectional view taken along line MM in FIG.

19 is a sectional view taken along line NN of FIG.

20 is a sectional view taken along line P-P of FIG.

FIG. 21 is a partial plan view of a cylinder head showing a structure for supplying oil to a cam shaft.

22 is a sectional view taken along line QQ of FIG.

23 is a cross-sectional view taken along the line RR of FIG.

[Explanation of symbols]

 1 Cylinder Head 1A Cylinder Head Body 1a Cylinder Head Cover Attachment Part 10 Cam Carrier 11 Lifter Guide Part 12 Cam Journal 20 Cylinder Head Cover

Claims (1)

[Claims] 1. A cam carrier integrally including at least a cam shaft journal and a lifter guide portion is formed separately from a cylinder head body, and the cam carrier is tightened and integrated with the cylinder head body, and the cylinder head body is also provided. A cylinder head structure for an engine that is provided with a cylinder head cover mounting part.