JPH10220331A - Structure of individual ignition coil for multicylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the upper surface of a bracket, supporting an individual ignition coil, in a plane and W reduce the manufacturing cost of the bracket by a method wherein a socket part is made of soft synthetic resin and bendable to a shaft part on which the socket part is mounted. SOLUTION: The socket part 19c of each individual type ignition coil 19 is made of soft synthetic resin, such as silicone resin and a necking part 19d is formed in a peripherally extending state on the outer periphery thereof. The socket part 19c is formed bendably to a shaft part 19b on which the socket part 19c is attached. In each individual ignition coil 19, after the shaft part 19b is inserted downward in an insertion hole 20a formed in a bracket 20, the socket part 19c at the tip thereof is removably connected in a state to be linearly aligned with the axis 17a of an ignition plug 17, mounted in a screwed-in state on a cylinder head 3. This constitution forms the upper surface of the bracket 20, supporting each individual ignition coil 19, in a plane and reduces a manufacturing cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an individual ignition coil in a multi-cylinder internal combustion engine, in which ignition coils are individually and individually configured for each cylinder.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3 of Japanese Utility Model Laid-Open Publication No. 4-66356, for example, an individual ignition coil of this type has a head portion provided with a connector for electrical connection. Part is integrally protruded, and the coil is provided in the head or in both the head and the shaft part, or provided in the shaft part, and the socket part is provided at the tip of the shaft part, The part is detachably fitted to the ignition plug screwed to the cylinder head in a state where the axis of the socket is aligned with the axis of the ignition plug in a straight line, and the head is connected to the ignition plug. A structure in which a lower surface of the head portion is detachably mounted by fastening bolts to a supporting bracket disposed so as to extend in the direction of the cylinder row above each ignition plug in a state where the lower surface of the head portion is in close contact with the upper surface of the bracket. doing.

[0003]

However, the conventional individual ignition coil has a structure in which the socket for fitting connection to the ignition plug is always linear with the shaft to which the socket is attached. Therefore, the conventional individual ignition coil is configured such that the axis of the spark plug for each cylinder of the multi-cylinder internal combustion engine is obliquely inclined with respect to the cylinder axis of each cylinder when viewed from a horizontal direction perpendicular to the crankshaft. However, when the present invention is applied to a device mounted on a vehicle, as described below, the shape of the support bracket for each of the individual ignition coils becomes complicated, and there is a problem that the cost required for manufacturing the bracket is greatly increased. Was.

That is, the spark plug for each cylinder of the multi-cylinder internal combustion engine is inclined with respect to the cylinder head at an angle to the cylinder axis of each cylinder when the axis of the spark plug is viewed from a horizontal direction perpendicular to the crankshaft. When the individual ignition coil according to the above-described conventional configuration is applied to the cylinder, the socket and the shaft of each individual ignition coil have cylinders in each cylinder when viewed from a horizontal direction perpendicular to the crankshaft. By tilting obliquely with respect to the axis, the lower surface of the head portion of each individual ignition coil does not become parallel to the axis of the crankshaft when viewed from a horizontal direction perpendicular to the crankshaft. Of each individual type ignition coil, the upper surface of the bracket supporting each individual type ignition coil When mounting the head portion of the coil by tightening bolts with its lower surface in close contact, each of the close contact portions in the head portion of each individual ignition coil on the upper surface of the support bracket is replaced with the crankshaft. Since the bracket must be formed on an inclined surface inclined with respect to the axis, the shape of the bracket is complicated.

The present invention raises this problem, that is, when the spark plugs in each cylinder of a multi-cylinder internal combustion engine are inclined with respect to the cylinder axis, the cost required for manufacturing a bracket for supporting an individual ignition coil for the spark plugs increases. It is a technical task to solve the problem.

[0006]

In order to achieve this technical object, the present invention relates to a technique of "protruding a shaft downward from a head provided with a connector for electrical connection, and screwing a tip of the shaft into a cylinder head. In the individual ignition coil, the socket portion for fitting connection to the attached spark plug is mounted, and the lower surface of the head portion is configured as a mounting surface with respect to the upper surface of a support bracket disposed above the spark plug. The socket for fitting connection to the ignition plug in the shaft of the individual ignition coil is made of a soft synthetic resin, and this socket is configured to be bendable with respect to the shaft to which the socket is attached. ".

[0007]

As described above, the socket for connection to the ignition plug in the individual ignition coil is made of a soft synthetic resin, and this socket is bent with respect to the shaft to which the socket is attached. By being configured to be possible, the spark plug for each cylinder in the multi-cylinder internal combustion engine,
When the axis of the ignition plug is attached to the cylinder head so as to be obliquely inclined with respect to the cylinder axis of each cylinder when viewed from a horizontal direction perpendicular to the crankshaft, the connection in the individual ignition coil is performed. The socket for the socket is bent with respect to the shaft of the ignition plug under the condition that the axis of the socket is aligned with the axis of the ignition plug in a straight line and the socket can be securely connected. Portion, the axis of which can be in a posture parallel to the cylinder axis, and thus, when the lower surface of the head portion is viewed from a horizontal direction perpendicular to the crankshaft,
It can be made parallel to the axis of the crankshaft and can be aligned so that each individual ignition coil is coplanar.

Therefore, according to the present invention, the upper surface of the bracket supporting each individual ignition coil can be made one plane, and the shape of the bracket can be simplified, so that the cost required for manufacturing the bracket is greatly reduced. It has the effect of being able to reduce.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 denotes a three-cylinder internal combustion engine including a first cylinder A1, a second cylinder A2, and a third cylinder A3.
Is constituted by a cylinder block 2 and a cylinder head 3 fastened to the upper surface thereof.

In the cylinder head 3, each cylinder A
Intake port 5 into combustion chamber 4 at 1, A2, A3
Is one longitudinal side surface 3a of the cylinder head 3
A single camshaft for opening and closing an intake valve 6 for the intake port 5 and an exhaust valve for the exhaust port (both not shown) is formed on the upper surface of the cylinder head 3. 8 is supported, and a head cover 9 that covers the cam shaft 8 is detachably attached.

Reference numeral 10 denotes an intake manifold for the internal combustion engine 1. The intake manifold 10 extends upward from a collecting pipe 10a to an intake port 5 in each of the cylinders A1, A2, and A3. A throttle body 11 having a built-in throttle valve 11a is provided at an upper end of the collecting pipe 10a, and an atmospheric air flow is provided upstream of the throttle body 11 at three ends of the branch pipe 10b, 10c, and 10d. The air cleaners 12 having the intake pipes 12a are respectively connected.

The throttle body 11 is removably attached to the cylinder head 3 via a bracket member 13, and the air cleaner 12
Is detachably attached to the throttle body 11 by fastening a bolt 14 or the like. On the other hand, a portion of the upper surface of the cylinder head 3 closer to the intake manifold 10 than the head cover 9 is provided with the cylinders A1, A2, A
The fuel injection valve 15 for injecting and supplying fuel into the intake port 5 at 3 has its axis 15a outwardly inclined by an appropriate angle θ1 with respect to the cylinder axis 16 of each cylinder as viewed from the direction of the axis of the crankshaft. The upper end of each fuel injection valve 15 is connected to the fuel delivery pipe 1.
8 is connected.

Further, on the portion of the upper surface of the cylinder head 3 closer to the intake manifold 10 than the head cover 9, an ignition plug 17 for the combustion chamber 4 of each of the cylinders A 1, A 2, A 3 has an axis 17 a corresponding to a crankshaft. Screwed in such a manner as to be inclined outward by an appropriate angle θ2a with respect to the cylinder axis 16 in each cylinder as viewed from the direction of the axis of the cylinder, and to be appropriately inclined by an angle θ2b as viewed from a horizontal direction perpendicular to the axis of the crankshaft. Have been.

Reference numeral 19 denotes an individual ignition coil,
The individual ignition coil 19 is connected to the connector 1 for electrical connection.
The shaft portion 19b is integrally projected downward from the head portion 19a provided with the shaft 9f, and the coil is provided in the head portion 19a or in both the head portion 19a and the shaft portion 19b. A socket 19c is provided at the tip of the shaft 19b.
c is detachably fitted to the ignition plug 17 screwed to the cylinder head 3 with the axis of the socket portion 19c aligned with the axis 17a of the ignition plug 17 in a straight line. A coil-shaped conductor 19e for electrically connecting the ignition plug 17 to the coil is provided inside the shaft portion 19b and the socket portion 19c.

The head portion 19a of each of the individual ignition coils 19 is disposed so as to extend above the respective ignition plugs 17 in the axial direction of the crankshaft, and is attached to the cylinder head 3. The lower surface 19a 'of the head portion 19a is detachably attached to the plate-shaped bracket 20 by fastening bolts 21 in a state of being in close contact with the upper surface 20b of the bracket 20.

The socket 19c of each of the individual ignition coils 19 is made of a soft synthetic resin such as a silicone resin, and a constricted portion 19d is provided on the outer periphery so as to extend in the circumferential direction. The socket 19c is attached to the shaft 19 to which the socket 19c is attached.
It is configured to be able to bend with respect to b. In this configuration, each individual ignition coil 19 has its shaft 1
9b is inserted downward into an insertion hole 20a formed in the bracket 20, and the socket 19c at the tip thereof is connected to the ignition plug 17 screwed to the cylinder head 3 with the axis of the socket 19c. After being removably fitted and connected in a state of being aligned with the axis 17a of the ignition plug 17 in a straight line, the head portion 19a is attached to the bracket 20 by fastening with a bolt 21.

In this case, when the socket portion 19c of each individual ignition coil 19 is configured so as not to bend with respect to the shaft portion 19b to which the socket portion 19c is attached as in the conventional case, As shown by a two-dot chain line in FIG. 2, the shaft portion 19b of the ignition coil 19 is inclined at an appropriate angle θ2b with respect to the cylinder axis 16 similarly to the ignition plug 17, and as a result, each individual When the lower surface of the head portion 19a of the ignition coil 19 is viewed from a horizontal direction perpendicular to the crankshaft,
When the head portion is mounted on a bracket, the bracket is shown by a two-dot chain line in FIG. 2 because the head portion is not inclined parallel to the axis of the crankshaft but is inclined with respect to the axis of the crankshaft. As described above, the bracket 20 ″ in which each of the close contact portions of the head portion of each individual ignition coil on the upper surface of the bracket is formed on an inclined surface inclined with respect to the axis of the crankshaft, that is, the bracket 20 ″ is made of metal In the case where the bracket 20 "is made of a plate, the shape of the bracket 20" becomes complicated because the metal plate must be bent in a stepwise manner.

On the other hand, each of the individual ignition coils 19
As described above, when the socket portion 19c is configured to be bendable with respect to the shaft portion 19b to which the socket portion 19c is attached, the ignition plug 17 for each cylinder A1, A2, A3 is attached to the cylinder head 3. On the other hand, even if the axis 17a of the spark plug 17 is mounted so as to be inclined at an appropriate angle θ2b with respect to the cylinder axis 16 of each cylinder when viewed from a horizontal direction perpendicular to the crankshaft, The connection socket 19c of the coil 19 is connected to the ignition plug 17 by the socket 19
Under the condition that the axis of c is aligned with the axis 17a of the ignition plug 17 in a straight line and the fitting can be securely connected, the socket 19c of the socket 19c is bent by bending the shaft 19b to the shaft 19b. As shown in the figure, the axis of the crankshaft can be made parallel to the cylinder axis 16, and the lower surface 19a 'of the head portion 19a is viewed from a horizontal direction perpendicular to the crankshaft. And the individual ignition coils 19 can be arranged so as to be flush with each other, so that the metal plate bracket 20 to which the head portion 19a is attached can be formed in a flat shape having an extremely simple shape. It can be a face plate.

An insertion hole 20 formed in the bracket 20
a can be fitted and connected to the ignition plug 17 in a state where the shaft portion 19b and the socket portion 19c are straightened by forming an oval hole, and thereafter, the head portion 19a
Is shifted so that the shaft portion 19b bends with respect to the socket portion 19c, and the lower surface 19a 'thereof is attached to the bracket 20 after the lower surface 19a' is brought into close contact with the upper surface of the bracket 20.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention.

FIG. 2 is a side view taken along the line II-II of FIG.

FIG. 3 is a plan view taken along line III-III of FIG. 2;

FIG. 4 is a partially cutaway front view of the individual ignition coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder block 3 Cylinder head 16 Cylinder axis 17 Spark plug 19 Individual ignition coil 19a Head part 19a 'Lower surface of head part 19b Shaft part 19c Socket part 19d Neck part 20 Bracket 20b Upper surface of bracket

Claims (1)

[Claims] 1. A shaft portion protrudes downward from a head portion provided with a connector for electrical connection, and a socket portion for fitting connection to an ignition plug screwed to a cylinder head is attached to a tip of the shaft portion. An individual ignition coil in which a lower surface of a head portion is a mounting surface for an upper surface of a support bracket disposed above the ignition plug, wherein the individual ignition coil has a shaft portion to be fitted to the ignition plug. The structure of the individual ignition coil in the multi-cylinder internal combustion engine, characterized in that the socket portion is made of a soft synthetic resin, and the socket portion is configured to be bent with respect to a shaft portion to which the socket portion is attached.