JPH078991U - Spark plug plug cap - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a plug cap for an ignition plug capable of adapting plug caps of different lengths with a pair of connecting fittings by varying the axial length of the connecting fittings of the plug cap. A connecting fitting for electrically connecting the ignition plug 3 and the ignition coil 2 is provided with a first connecting fitting 11 connected to the ignition coil 2 and a second connecting fitting connected to the ignition plug 3. It is composed of 12 and. The cylindrical shaft portions 11a and 12a of the first and second connection fittings 11 and 12 are adjustably fitted to each other at relative positions in the axial direction to change the total length of the connection fittings, and both shaft portions 11a. , 12a are fitted to each other to prevent relative positional deviation between the two in the axial direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a spark plug plug cap that electrically connects, for example, a spark plug of an automobile gasoline engine and an ignition coil that supplies a high voltage to the spark plug.

[0002]

[Prior art]

 Conventionally, a so-called distributorless ignition method has been used in which an ignition coil is individually provided in each spark plug to improve ignition power. In this distributorless ignition system, as shown in FIG. 4, an ignition coil 2 mounted on an engine head 1 and a spark plug plug cap 10 for directly connecting a spark plug 3 are used. There is. The plug cap 10 has one end engaged with the terminal fitting 2b of the ignition coil 2, and a tubular connecting fitting 11 extending toward the ignition plug 3 and ignition of the connecting fitting 11. From a contact spring 13 attached to the end portion on the plug 3 side and pressed against the terminal fitting 3a of the ignition plug 3, and a tubular insulator 14 that covers and insulates the connection fitting 11 and the contact spring 13. It is configured. One end 14b of the insulator 14 is externally fitted to the insulating portion 2a on the ignition coil 2 side, and the seal portion 14a abuts on the engine head 1 to prevent water and dust from entering the plug hole 1a. The end portion 14c on the ignition plug 3 side is fitted onto the insulating portion 3b of the ignition plug 3 so as not to enter.

[0003]

[Problems to be solved by the device]

 Since the depth L1 of the plug plug hole 1a differs depending on the engine, the overall length of the plug cap 10 also has different dimensions. As a result, the length L2 of the above-mentioned connecting fitting 11 must also be different according to the depth L1 of the plug plug hole 1a. However, since the connection fitting 11 is manufactured by press-molding a thin plate, a new press die must be manufactured in order to change the length of the connection fitting, resulting in an increase in cost and the connection fitting. There was a problem that the number of types increased and management became extremely complicated. Therefore, an object of the present invention was made in view of the above circumstances, and it is an object of the present invention to provide a connection fitting that can be used for plug caps of different lengths.

[0004]

[Means for Solving the Problems]

 The above-mentioned object of the present invention is provided with a connecting metal fitting, one end of which is connected to an ignition plug of an internal combustion engine and the other end of which is electrically connected to an ignition coil, and an insulator for housing and insulating the connecting metal fitting. A plug cap for a spark plug, wherein the connecting fitting comprises a first connecting fitting connected to the ignition coil and a second connecting fitting connected to the ignition plug, and This is achieved by a spark plug plug cap which is characterized in that the first connecting member and the second connecting member are fitted so as to be adjustable at relative positions in the axial direction.

[0005]

[Action]

 In the plug cap for a spark plug according to the present invention, the connecting fitting comprises a first connecting fitting connected to the ignition coil and a second connecting fitting connected to the spark plug, and the first fitting The connection fitting and the second connection fitting are adjustably fitted to each other at a relative position in the axial direction, whereby the connection fitting can be adjusted to a predetermined length. Therefore, even a plug cap having a different length can be handled by the pair of connecting fittings.

[0006]

【Example】

 An embodiment of a spark plug cap according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same parts as those of the conventional example will be denoted by the same reference numerals to simplify the description.

As shown in FIG. 1, the structure of the plug cap 100 is almost the same as that of the conventional plug cap 10 except for the structure of the connection fitting. That is, the connecting fitting of the plug cap 100 has a first connecting fitting 11 having one end engaged with the terminal fitting 2b of the ignition coil 2 and the other end serving as a cylindrical shaft portion 11a extending toward the ignition plug 3. And a second connection fitting that is adjustably fitted to the first connection fitting 11 at a relative position in the axial direction.

As shown in FIG. 2, the first connection fitting 11 is a thin metal plate formed by press molding, and has a conical bulge at one end of the cylindrical shaft 11 a. A portion 11b is provided, and at its tip, a cylindrical portion 11c is fitted on the terminal fitting 2b of the ignition coil 2, and a part of the cylindrical portion 11c is reduced in diameter to engage with the terminal fitting 2b. A mating engaging portion 11d is provided. The shaft portion 11a is formed with a plurality of step portions 11e that are bulged in the radial direction. The second connection fitting 12 is formed by press-molding a thin metal plate, like the first connection fitting, and has a conical bulge at one end of the cylindrical shaft 12a. A portion 12b is provided, and a cylindrical portion 12c for accommodating the contact spring 13 is provided at the tip thereof. A step portion 12e that bulges in the radial direction is formed near the end portion on the opposite side of the shaft portion 12a.

Next, as shown in FIG. 3, the shaft portion 11 a of the first connection fitting 11 is externally fitted to the shaft portion 12 a of the second connection fitting 12 such that the relative position in the axial direction is adjustable. ing . At this time, the step portion 12e which is an annular convex portion formed on the outer surface of the second connection fitting 12 and the step portion which is an annular recess formed on the inner surface of the first connection fitting 11 are formed. The portion 11e and the portion 11e are fitted to each other to position the relative position in the axial direction of the both and to prevent the positional deviation. As a result, in the connection fitting of the present embodiment, the total length L2 can be selected from four levels from L2 (MAX) to L2 (MIN) by selecting the fitting position of the step portions 11e and 12e. This set of fittings can accommodate plug caps of different lengths.

On the other hand, the insulator 14 is individually manufactured by injection molding from an insulating rubber material in accordance with the entire length of the plug cap 100.

Next, the assembly of the plug cap 100 of this embodiment will be described. In order to assemble the plug cap 100, first, the shaft portions 11a and 12a of the first and second connecting fittings 11 and 12 are fitted to each other, and the step portions 11e and 12e are selected. Then, they are fitted to each other and positioned to a predetermined length L2. Then, the contact spring is press-fitted into the cylindrical portion 12c of the end of the second connection fitting 12 to complete the attachment connection fitting.

The assembled fitting is inserted into the insertion hole of the insulator 14 with the cylindrical portion 11 c provided at the end of the first fitting 11 as the tip. At this time, in the present embodiment, the cylindrical portion 11c is formed to be thinner than the shaft portion 11a of the first connection fitting 11, and a conical bulge portion 11b is provided following the cylindrical portion 11c. Therefore, the connection fitting can be easily inserted into the insulator 14. Further, at the stage where the connection fitting is completely stored in the insulator 14, the bulging portions 11b and 12b provided on the first and second connection fittings 11 and 12 engage with the insulator 14. Therefore, the connecting fittings 11 and 12 and the insulator 14 are not displaced from each other in the axial direction.

Next, the attachment of the plug cap 100 of this embodiment to the engine head 1 will be described with reference to FIG. When the plug cap 100 is attached to the ignition coil 2, the cylindrical portion 14b at the tip of the insulator 14 is externally fitted to the insulating portion 2a of the ignition coil 2 to insulate, and the cylindrical portion at the tip of the first connecting fitting 11 is attached. The portion 11c is fitted onto the terminal fitting 2b of the ignition coil 2 and is prevented from coming off by the locking portion 11d. Then, when the plug cap 100 integrated with the ignition coil 2 is inserted into the plug hole 1a of the engine head 1 and attached to the spark plug 3, the cylindrical portion 14c at the end of the insulator 14 becomes the spark plug 3. The contact spring 13 attached to the end of the second connecting fitting 12 comes into contact with the head of the terminal fitting 3a of the spark plug 3 while being externally fitted to the insulating portion 3b for insulation. At this time, the expansion and contraction of the contact spring 13 absorbs the variation in the relative position between the plug cap 100 and the spark plug 3.

That is, in the plug cap 100 of the present embodiment, the shaft portions of the first and second connection fittings 11 and 12 are provided with step portions 11e and 12e, respectively, and these step portions are selected. Since the positioning in the axial direction is performed by fitting them, the assembling work of both can be easily performed, and the positional deviation of the connecting fittings in the axial direction can be prevented. If the shaft portions 11a and 12a of the first and second connection fittings 11 and 12 are formed into a simple cylindrical shape and are assembled by press fitting, the relative position in the axial direction of both can be set steplessly. .

[0015]

[Effect of device]

 In the plug cap for an ignition plug of the present invention, one end is connected to the ignition plug of the internal combustion engine and the other end is connected to the ignition coil, and a connecting fitting for electrically connecting them is connected to the ignition coil. Connection fitting and a second connection fitting connected to the ignition plug, and the first connection fitting and the second connection fitting are adjustably fitted at relative positions in the axial direction. By doing so, it is possible to change the length of the plug cap connecting fittings in the axial direction, and therefore, when forming plug caps of different lengths, one set of connecting fittings can be used. Therefore, since it is not necessary to manufacture a new connection fitting for each individual plug cap, it is possible to reduce the manufacturing cost of the press die for press-molding the plug cap and reduce the types of connection fittings. It is possible to improve parts management.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing the attachment of an embodiment of a plug cap according to the present invention.

FIG. 2 is an enlarged explanatory view of the first and second connection fittings of the plug cap of the present invention.

FIG. 3 is an explanatory diagram illustrating assembly of first and second connection fittings.

FIG. 4 is an overall cross-sectional view showing attachment of a conventional plug cap.

[Explanation of symbols]

1 Engine Head 1a Plug Hole 2 Ignition Coil 2a Ignition Coil Insulation 2b Ignition Coil Terminal Metal 3 Ignition Plug 3a Ignition Plug Terminal Metal 3b Ignition Plug Insulation 3c Ignition Plug Attachment Screw 10 Conventional Plug Cap 11th No. 1 connection fitting 11a Shaft portion of the first connection fitting 11b Swelling portion of the first connection fitting 11c Fitting portion of the first connection fitting with the ignition coil 11d Locking of the first connection fitting with the ignition coil Part 11e Step part of the first connecting fitting 12 Second connecting fitting 12a Shaft part of the second connecting fitting 12b Swelling part of the second connecting fitting 12c Contact spring attachment part of the second connecting fitting 12e Second Locking part of the connection fitting with the ignition coil 13 Contact spring 14 Insulator 14 a seal part 14b fitting part with ignition coil 14c fitting part with ignition plug 100 plug cap of the present invention

Claims (1)

[Scope of utility model registration request] 1. A connecting fitting, one end of which is connected to an ignition plug of an internal combustion engine and the other end of which is electrically connected to an ignition coil, to electrically connect the two, and an insulator for housing and insulating the connecting fitting. In the plug cap for a spark plug, the connection fitting comprises a first connection fitting connected to the ignition coil and a second connection fitting connected to the ignition plug, and the first connection fitting. A plug cap for an ignition plug, wherein the second connection fitting is adjustably fitted at a relative position in the axial direction.