JPH05280418A - Cylinder head cover of engine - Google Patents

Abstract

PURPOSE:To improve stiffness of a cover, improve supporting stiffness of a coil, improve sealing performance of the joint part of a cover circumferential part to a cylinder head, and so on, in the case where coils for ignition plugs are installed on a cylinder head cover, in a DOHC engine. CONSTITUTION:A cylinder head cover 10 is provided with a pair of projection parts 11, 11 which are provided in parallel on both side parts of the cylinder head cover 10, and with which two cam shafts are covered respectively, and a recessed part 12 extending in cam shaft direction, between the projection parts 11, 11. Opening parts 18...18 for inserting coils 4...4 for an ignition plug are provided in positions opposing to respective cylinders in the recessed part 12. And also, ribs 15...15 for connecting together a pair of the projection parts 11, 11 are formed in positions between respective opening parts 18...18, and bosses 19...19 for installation thereof are provided on the ribs 15...15 so as to stand the soils 4...4 in one line in cam shaft direction.

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 cover, and more particularly to a DLI (Distributor L).
DOH adopting ess Ignition system
The present invention relates to a cylinder head cover of a C engine.

[0002]

2. Description of the Related Art In recent years, in engines for automobiles, for example, as disclosed in Japanese Utility Model Application Laid-Open No. 61-167417, an ignition system in which an ignition coil is directly attached to an ignition plug of each cylinder is disclosed. By controlling the ignition of the plug, a DLI system that does not require a distributor is being adopted.

In this case, the ignition coils are arranged in the same number as the number of cylinders above the cylinder head.
In the engine disclosed in the above publication, in the DOHC engine, the ignition coils are arranged in a line between the rocker covers respectively covering the two cam shafts and individually fixed to the cylinder head, and above the ignition coils. Is covered with an upper cover installed between the rocker covers.

[0004]

By the way, when the DLI system is adopted in the DOHC engine as described above, in the configuration disclosed in the above publication, two cam shafts and the same number as the number of cylinders are provided above the cylinder head. The above structure complicates the configuration of the upper part of the head, and as a cylinder head cover that covers the upper part of the cylinder head, two rocker covers that respectively cover two cam shafts, and an ignition coil. An upper cover for covering the above is required, which leads to an increase in the number of parts.

On the other hand, it is conceivable that the same number of ignition coils as the number of cylinders are attached to a single cylinder head cover that covers two cam shafts. However, in this case, the following problems will occur.

That is, while the ignition coil is connected to the ignition plug attached to the cylinder head, an electric cord introduced from the outside of the engine is connected to the ignition coil, so that an opening for inserting the coil is formed in the cylinder head cover. It is necessary to provide the same number of cylinders as the number of cylinders, which reduces the rigidity of the cylinder head cover. Then, since the ignition coil is attached to the cover whose rigidity has been lowered, sufficient support rigidity for the coil cannot be obtained and the support becomes unstable. Further, due to insufficient rigidity, the cylinder head cover is deformed by the weight of the coil, and therefore, the cover peripheral portion floats up particularly at a portion of the peripheral surface of the cover near the support portion of the coil in the surface where the cylinder head is mated with the cylinder head. Therefore, the sealing property in the above will be deteriorated.

[0007] Such a problem becomes particularly noticeable when the cylinder head cover is made of synthetic resin for weight reduction.

Therefore, it is an object of the present invention to prevent the above problems by effectively increasing the rigidity of the ignition plug coil when it is attached to the cylinder head cover.

[0009]

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

That is, the invention according to claim 1 of the present application (hereinafter,
A first invention) is a cylinder head cover attached to an upper part of a cylinder head of a DOHC engine, and includes a pair of convex portions provided in parallel on both sides and respectively covering two cam shafts, and a pair of convex portions of these convex portions. And a recess extending in the cam axis direction between them, the insertion port of the spark plug coil is opened at a position corresponding to each cylinder in the recess, and the pair of protrusions is provided at a position between the insertion ports. It is characterized in that connecting ribs are formed, and the mounting bosses are provided on these ribs so that the coils are arranged in a line in the cam axis direction.

Further, the invention according to claim 2 (hereinafter referred to as the second invention) is similar to the above-mentioned first invention in that a pair of convex portions provided in parallel on both sides and between these convex portions are provided. In a cylinder head cover of a DOHC engine having a recessed portion extending in the cam axis direction, a spark plug coil insertion port is opened at a position corresponding to each cylinder in the recessed portion, and the pair of insertion holes is provided at a position between the insertion ports. Ribs that connect the protrusions are formed. And on these ribs,
A mounting boss is provided so that the coils are aligned in a line in the cam axis direction, and a bolt for tightening the cylinder head is provided around the cover on the extension line of the rib in the direction orthogonal to the cam axis direction. It is characterized in that an insertion hole is provided.

[0012]

According to the above construction, in both the first and second inventions, the pair of convex portions on both sides extending in parallel are connected by the ribs at the positions between the respective insertion openings of the spark plug coil. As a result, the rigidity of the cylinder head cover in the width direction is increased. Further, since the ignition coils of the respective cylinders are attached to the bosses provided on the ribs so as to be aligned in a row in the cam axis direction, the ribs, the bosses, and the coils are formed at the center portion in the width direction of the cylinder head cover. As a result, a series of high-rigidity portions extending in the cam axis direction are formed. Therefore, the cylinder head cover has the high-rigidity portion in a grid pattern by the high-rigidity portion, the high-rigidity convex portions on both sides of the high-rigidity portion, and the ribs extending in the direction orthogonal to the high-rigidity portions. The rigidity as a whole is effectively improved.

Further, according to the above construction, the weight of the coil acts on the rib by attaching the coil to the boss provided on the rib connecting the pair of convex portions. According to this, since the cover is fastened to the cylinder head at the peripheral portion of the cover on the extension line in the direction orthogonal to the cam axis direction of the rib, the weight of the coil is covered via the rib on the extension line. Even if the peripheral portion is affected, the problem that the portion is lifted from the mating surface of the cylinder head does not occur.

[0014]

EXAMPLES Examples of the present invention will be described below.

As shown in FIGS. 1 and 2, a cylinder head cover 10 according to this embodiment has a pair of protrusions 11, which are provided in parallel on both sides and accommodate two cam shafts 1, 1, respectively. 11, a concave portion 12 extending in the cam axis direction between the convex portions 11, 11, and a pair of gears provided at one end portion of the cover 10 and attached to the end portions of the cam shafts 1, 1. 2 and 2 are accommodated in the gear accommodating portion 13, and a large number of bolt insertion holes 14 for fastening to a cylinder head (not shown) are provided in the peripheral portion of the cover 10.
... 14 is provided.

A rib 15 for connecting a pair of convex portions 11, 11 located on both sides is provided at a portion of the concave portion 12 corresponding to each cylinder and an end portion on the opposite side of the gear accommodating portion 13. ... 15 is provided, and both convex portions 11,
11 is connected by a connecting portion 16 at the end portion on the gear storage portion 13 side, and by these configurations, the inside of the recessed portion 12 is almost the same as the number of cylinders (four in the illustrated example) of spaces 17 ... It is in a partitioned state.

Then, as shown in FIGS. 2 and 3, the openings 18 ...
18 are provided, and in these openings 18 ... 18,
Spark plugs 3 ... 3 arranged in the center of the combustion chamber of each cylinder
4 are connected to the ignition coils 4 ... The ribs 15 ... 15 and the connecting portion 16 are arranged in a line along the center line of the cover 10 so as to be located on both sides of the openings 18 ... 18 and as shown in FIG. So that the coil mounting bosses 19 ... 19
Are provided, and the ignition coils 4 ... 4 are attached to these bosses 19 ... 19 by bolts 5 ... 5.

Here, in this embodiment, the ribs 15 ...
Three ribs 15 provided between the cylinders among the 15
The a ... 15a is connected to only one of the pair of protrusions 11, 11 and not to the other, but the tips of these ribs 15a ... 15a and the ribs 15a.
Bosses 20 ... 20 each having a bolt insertion hole 14 ′ for fastening the cover 10 to the cylinder head are provided between the bosses 20 that are not connected to each other. Therefore, as shown in FIG. 4, the ribs 15a ... 15a and the bosses 20 ... 20 are connected to the protrusions 11 on both sides, and the ribs 15a ... 15a and the bosses 20 ... A rib with high rigidity is formed to connect the convex portions 11 on both sides.

Then, as shown in FIG.
15a and the bosses 20 ... 20, the extension of the high-rigidity portion in the direction orthogonal to the cam axis direction, which is approximately the extension line X ... The insertion holes 14a ... 14a are arranged.

According to the above configuration, the pair of convex portions 11, 1
18 are formed in the recessed portions 12 extending in the cam axis direction between the first and second cylinders, the number of openings 18 ... 18 for inserting the ignition coil is the same as the number of cylinders, so that the cylinder head cover 10 is particularly rigid in the recessed portions 12. However, the pair of protrusions 11 and 11 are connected to each other by the connecting portion 16 at the end on the gear accommodating portion 13 side, by the rib 15 at the opposite end, and between the cylinders. At the position, the ribs 15a and the boss 20 are connected to each other.
A plurality of high-rigidity portions in the direction orthogonal to the cam axis direction are formed between the convex portions 11 on both sides.

The connecting portion 16 and the ribs 15 ... 15 are also provided.
, 18 provided at the bottom of the recessed portion 12 ...
19 are provided on both sides of the cover 10 so as to be aligned in a line along the center line of the cover 10, and the ignition coil 4 of each cylinder is connected to connect the bosses 19 to 19. .. 4 are attached, the bosses 19 ... 19 and the coils 4 ... 4 form one high-rigidity portion extending in the cam axis direction in the recess 12 having low rigidity.

Therefore, this cylinder head cover 1
At 0, one high-rigidity portion extending in the cam axis direction at the center and a pair of highly-rigid convex portions 1 extending in parallel on both sides thereof.
1, 11 and a plurality of high-rigidity portions that connect the convex portions 11, 11 on both sides orthogonal to these are formed, and by forming these in a lattice shape, the rigidity of the cover 10 as a whole is effective. It will be raised to.

As a result, the supporting rigidity of the coils 4 ... 4 attached to the cover 10 is improved and the attached state is stabilized, and the peripheral surface of the cover 10 on the mating surface with the cylinder head. The sealing property will be secured.

In particular, according to the above configuration, the rib 15a and the boss 20 that connect the pair of protrusions 11 and 11 together.
The hole 14 for inserting the bolt for tightening into the cylinder head is formed on the extended line of the high rigidity portion consisting of
14a is provided, the cover 10 can be fastened to the cylinder head at this portion even if the weight of the coils 4 ... 4 acts on the mating surface on the extension line via the high rigidity portion. As a result, the mating surface of the cover 10 does not float up from the cylinder head side, which further improves the sealing performance at the mating surface with the cylinder head.

[0025]

As described above, according to the present invention, the DOHC having the same number of ignition plug coils as the number of cylinders is attached.
In a cylinder head cover of a type engine, a pair of convex portions extending in parallel to both sides are connected by ribs, and the coil and its coil are provided along a concave portion where the insertion port of the coil between the both convex portions is opened. By forming a series of high-rigidity portions with the mounting boss, the entire cover is reinforced on the lattice. As a result, the rigidity for supporting the ignition coil is increased, the mounting state thereof is stabilized, and the deformation of the cover is prevented, and even when the cover is made of synthetic resin, the mating surface with the cylinder head is improved. In this case, good sealing property can be secured.

[Brief description of drawings]

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

FIG. 2 is a vertical sectional front view of the cylinder head cover taken along the line AA of FIG.

3 is a vertical cross-sectional side view of the cylinder head cover taken along the line BB of FIG.

FIG. 4 is a vertical sectional side view of the cylinder head cover taken along the line C-C of FIG. 1.

[Explanation of symbols]

 1 Camshaft 3 Spark Plug 4 Coil 10 Cylinder Head Cover 11 Convex Part 12 Recessed Part 14 Cover Tightening Boss 15 Rib 18 Coil Insertion Port (Opening) 19 Coil Mounting Boss

Claims (2)

[Claims] 1. A cylinder head cover mounted on an upper portion of a cylinder head of a DOHC engine, comprising a pair of convex portions provided in parallel on both sides and respectively covering two cam shafts, and between the convex portions. A recess extending in the direction of the cam axis, and an insertion port for the spark plug coil is opened at a position corresponding to each cylinder in the recess, and the pair of protrusions are connected to a position between the insertion ports. Cylinder head cover for an engine, characterized in that ribs for forming the same are formed, and that these ribs are provided with mounting bosses so that the coils are arranged in a line in the cam axis direction. 2. A cylinder head cover attached to an upper portion of a cylinder head of a DOHC engine, wherein a pair of convex portions provided in parallel on both sides and covering two cam shafts respectively, and between the convex portions. A recess extending in the direction of the cam axis, and an insertion port for the spark plug coil is opened at a position corresponding to each cylinder in the recess, and the pair of protrusions are connected to a position between the insertion ports. Ribs are formed, and the mounting bosses are provided on these ribs so that the coils are aligned in a row in the cam axis direction, and the ribs extend in a direction orthogonal to the cam axis direction. A cylinder head cover for an engine, characterized in that an insertion hole for a bolt for fastening to the cylinder head is provided in a peripheral portion of the cover on a line.