JPH0525191Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a spark plug mounting structure, and more specifically, a spark plug mounting structure that allows a diesel engine to be easily converted into a spark plug-equipped engine such as a gas engine. Regarding.

[Technical background of the invention]

As is well known, a diesel engine pumps air into the combustion chamber of the engine, compresses it to a high temperature, and injects fuel into the compressed air to burn the fuel and operate the engine. It is an internal combustion engine. For this purpose, a gasoline engine is used in which a mixture of air and gasoline is sent into a combustion chamber and the mixture is exploded by a spark plug, or a fuel gas such as natural gas or propane gas is mixed with air and the spark plug is Unlike gas engines, which burn fuel in a straight line, they are not equipped with a spark plug; instead, they are equipped with a fuel injection nozzle to inject fuel into the fuel chamber.

In order to convert a diesel engine like the one mentioned above to an engine equipped with a spark plug like a gas engine or gasoline engine, you need to
It is necessary to remove the fuel injection nozzle and install the spark plug. In this case, use the injection nozzle mounting hole formed in the cylinder head for mounting the fuel injection nozzle,
It is reasonable to attach the spark plug to this fuel injection nozzle attachment hole.

As shown in FIG. 1, for example, as shown in FIG. 1, a spark plug 4 is inserted into a fuel injection nozzle mounting hole 2 formed in a cylinder head 1 through a gasket 3, and a hollow sleeve is inserted into the spark plug 4. 5 into the mounting hole 2 and abuts against the spark plug 4. On the other hand, a flange 6 is provided at the upper end of the sleeve 5, and by tightening the flange 6 into a screw hole formed in the cylinder head 1 with a bolt 7, the spark plug 4 can be installed. Generally, the structure is such that it is press-fitted into the fuel injection mounting nozzle hole 2.

According to the conventional spark plug mounting structure described above, it is necessary to provide a screw hole for tightening the bolt 7, but depending on the structure of the diesel engine, a cooling water channel is formed in the part where the screw hole is formed. In some cases, it may not be possible to form a screw hole due to reasons such as
There is also a diesel engine with a structure that allows for some expansion around the area.

[Purpose of invention]

This invention was made in view of the above points,
It is an object of the present invention to provide a mounting structure for mounting a spark plug to a diesel engine in which it is not possible to provide a screw hole as described above.

[Structure of the idea]

In order to achieve the above object, the spark plug mounting structure according to the present invention inserts a spark plug into a fuel injection nozzle mounting hole formed in a cylinder head, and presses the spark plug from above with a hollow sleeve. In the spark plug mounting structure, an adapter having a loose fitting hole into which the hollow sleeve can be loosely fitted is screwed and fixed to the upper end of the fuel injection nozzle mounting hole, and
The sleeve is loosely fitted into the loose fitting hole of the adapter and brought into contact with the spark plug, and the flange provided on the outer periphery of the hollow sleeve and the flange provided on the outer periphery of the adapter are fastened with bolts. It is characterized by

〔Example〕

FIG. 2 is a sectional view showing one embodiment of the present invention, and as is clear from this figure, the cylinder head 1
A fuel injection nozzle mounting hole 2 is formed in the
Spark plug 4 attaches gasket 3 to this mounting hole 2.
has been inserted through. The spark plug 4 is pressed into contact with the sleeve 5 from above and fixed in the nozzle mounting hole 2.

The sleeve 5 is hollow so that a wire harness (not shown) can be connected to the spark plug 4, and has a flange 6 on the outer periphery of the upper end of the sleeve.

On the other hand, at the upper edge of the fuel injection nozzle mounting hole 2,
A threaded groove is formed, and the adapter 8 is screwed and fixed to this threaded groove. This adapter 8 is provided with a flange 9 on the outer periphery of its upper end portion, which has a threaded hole through which a flange 6 provided on the sleeve 5 can be tightened and fixed with a bolt 7. The nozzle mounting hole 2 has a sleeve fitting hole 10 into which the sleeve 5 is loosely fitted so as to be movable in the axial direction of the nozzle mounting hole 2.

For this reason, after inserting the spark plug 4 into the fuel injection nozzle hole 2, the sleeve 5 is loosely fitted into the loose fitting hole 10 of the adapter 8, and the tip of the sleeve 5 is brought into contact with the spark plug 4. Afterwards, when the flange 6 of the sleeve 5 and the flange 9 of the adapter 8 are tightened with the bolts 7, the sleeve 5 is loosely fitted into the adapter 8, so that
The sleeve 5 presses the spark plug 4, and the spark plug 4 is fixed in the fuel injection nozzle hole 2.

At this time, the gasket 3 attached to the tip of the spark plug 2 for sealing is the spark plug 4.
It is obvious that the shape can be changed depending on the shape of the tip or the shape of the fuel injection nozzle mounting hole 2. For example, a gasket 3 having a shape as shown in FIGS. 3a and 3b may also be used.

Further, as shown in FIG. 4, a spacer 11 can be bridge-fixed between the cylinders to prevent the adapter 8 from loosening. That is, a spacer 11 is inserted through each of the bolts 7 for fastening the flange 6 of the sleeve 5 attached to one fuel injection nozzle mounting hole 2 and the flange of the adapter 8 to form a bridge, and the rotation of the adapter 8 is This prevents the adapter 8 screwed onto the cylinder head 1 from loosening.

[Effect of idea]

As explained above, according to the spark plug mounting structure according to the present invention, when it is not possible to provide a screw hole in the cylinder head, it is possible to simply provide a screw hole at the upper end of the fuel injection nozzle mounting hole.
This has the advantage that a spark plug can be installed, which is effective when upgrading a diesel engine to an engine that requires a spark plug, such as a gas engine.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional spark plug mounting structure, Fig. 2 is a sectional view showing an embodiment of the spark plug mounting structure according to the present invention, and Fig. 3 shows the shape of a gasket attached to the spark plug. FIG. 4 is a plan view showing a case where a spacer is provided in a spark plug mounting structure according to an embodiment of the present invention. 1... Cylinder head, 2... Fuel injection nozzle mounting hole, 3... Gasket, 4... Spark plug, 5... Sleeve, 6... Flange, 7...
Bolt, 3...Adapter, 9...Flange, 10
...Player hole, 11...Spacer.

Claims (1)

[Scope of utility model registration request] In a spark plug mounting structure in which a spark plug is inserted into a fuel injection nozzle mounting hole formed in a cylinder head and the spark plug is pressed from above by a hollow sleeve, the upper end of the fuel injection nozzle mounting hole An adapter having a loose fitting hole into which the hollow sleeve can be loosely fitted is screwed and fixed to the part, and the sleeve is loosely fitted into the loose fitting hole of the adapter to abut the spark plug, and the hollow sleeve is A spark plug mounting structure characterized in that a flange provided on the outer periphery of an adapter and a flange provided on the outer periphery of an adapter are fastened together with bolts.