JP3361699B2 - High pressure spark plug cap - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap for a high-pressure spark plug, which is improved so that a high-pressure spark plug can be easily and securely connected to an internal combustion engine.

[0002]

2. Description of the Related Art A conventional cap for a high pressure spark plug of an internal combustion engine is generally formed of a combination as shown in the longitudinal sectional view of FIG.

That is, a conventional cap 10 for a high pressure spark plug.
Is a cord cap portion 14 which houses a high-voltage cord 5 connected to a power source therein and which is formed of an insulating synthetic resin into a substantially cylindrical shape, and is fitted to an upper end portion of the cord cap portion 14, The upper surface 2 of the engine head is pressed by the seal lip portion 12 provided on the outer peripheral edge of the flange, while the cylindrical straight body portion 13 is provided inside the upper end of the engine hole portion 1 having a vertical hole formed through the engine head. And a rain cover portion 11 for fitting around the upper end portion of the engine hole portion 1 to seal the periphery thereof,
Integral with a cord fixing portion 15 which penetrates the side surface of the rain cover portion 11 and closes and grips the vicinity of the terminal portion of the high-voltage cord 5 arranged at the lower end portion of the cord cap portion 14 from the outer surface by compression deformation. A female plug terminal 17 formed by bridging the outer surface of the peripheral wall of the end wall with a half ring portion 16 so that a vertical mating end edge (not shown) of the peripheral wall that is formed into a cylindrical shape and is curved does not expand. , Respectively.

The conventional cap 10 for a high-pressure spark plug thus constructed is fitted from above onto a plug head (not shown) of a high-pressure spark plug 4 which is screwed to the bottom 3 of the engine hole 1. The high pressure ignition plug portion 4 and the female plug terminal 17 are formed by fitting the lower end surface of the cord cap portion 14 into the groove portion formed in the upper end surface of the elastic cap portion 18 made of insulating synthetic resin. Electrical connection was made.

[0005]

However, the above-described conventional cap 10 for a high-pressure spark plug is attached to the engine hole portion 1 and the high-pressure spark plug portion 4,
The fixed state was largely dependent on the degree of fitting at the following three points. That is, the cylindrical straight body portion 13 of the rain cover portion 11
And the degree of fitting between the upper end portion of the engine hole portion 1 and the lower end surface of the cord cap portion 14 and the elastic cap portion 18.
And the degree of fitting between the plug head of the high-pressure spark plug portion 4 and the female plug terminal 17, respectively.

The degree of fitting at these three locations is to maintain good sealing and insulating properties at both ends of the engine hole portion 1 and further good electrical connectivity of the high pressure spark plug portion 4.
It is necessary to set a fairly tight fitting state, and as a result, it takes a lot of labor and time to insert the high-pressure spark plug 4 into the internal combustion engine, and it is difficult to improve the assembling workability. there were.

The present invention solves the above-mentioned problems of the prior art and provides a cap for a high-pressure spark plug improved so that the operation of inserting the high-pressure spark plug into the internal combustion engine can be performed easily and reliably. The purpose is.

[0008]

The object of the present invention is to:
A cord cap portion formed by molding an insulating synthetic resin into a substantially cylindrical shape, and the upper end portion of the cord cap portion are fitted to each other, and a seal lip portion protruding from an outer peripheral edge of the flange presses the upper surface of the engine head. A rain cover part that penetrates through the side surface and a high pressure cord can be inserted, and a cord fixing part that tightly adheres and holds the vicinity of the end part of the high pressure cord disposed at the lower end of the cord cap part from the outer surface by compression deformation. A female plug terminal integrally formed with the spring contact, the spring contact being compressively deformable along the axis of the high-voltage cord;
A cap for a high-pressure spark plug, wherein an engine hole portion transparently provided from an upper surface of the engine head has an engaging recess formed in an inner peripheral surface in the vicinity of an upper end portion of the engine hole portion; The cap portion supports an elastic fixing member fitted from the upper end of the cord cap portion to the outer peripheral surface closer to the female plug terminal than the engaging recess, and is disposed corresponding to the engaging recess. This is achieved by a cap for a high-pressure spark plug, characterized in that a catching seat that allows the engaging claw portion of the elastic fixing member to engage with the engaging recess is provided.

Further, it is an object of the present invention that the rain cover portion is provided with a recessed portion therein, which is capable of receiving the swinging motion of the tip end portion of the elastic arm portion of the elastic fixing member. Achieved by the featured high pressure spark plug cap.

Further, the object of the present invention is that the cord cap portion projects a locking ridge on the outer peripheral surface above the seat, while the elastic fixing member inner peripheral surface of the cylindrical body portion. This is achieved by a cap for a high-pressure spark plug, characterized in that an engaging groove capable of engaging with the locking ridge is provided on a surface thereof.

Still another object of the present invention is that the cord cap portion has a vertically long lock which can accommodate the lock member on the outer peripheral surface thereof so that a part of the lock member can be engaged with the engaging recess. This is achieved by a cap for a high-pressure spark plug, which is characterized in that a storage portion is provided in a protruding manner.

The cap for a high-pressure spark plug of the present invention is fitted to the cord cap portion formed of an insulating synthetic resin in a substantially cylindrical shape and the upper end portion of the cord cap portion, and is provided on the outer peripheral edge of the flange. While the seal lip portion presses the upper surface of the engine head, a rain cover portion that can penetrate the side surface and into which a high-voltage cord can be inserted, and the vicinity of the end portion of the high-pressure cord disposed at the lower end portion of the cord cap portion A female plug terminal which is integrally formed with a cord fixing portion for closely contacting and gripping the outer surface by compression deformation and which is composed of a spring contactor capable of compression deformation along the axis of the high-voltage cord,
A cap for a high-pressure spark plug, wherein an engine hole portion transparently provided from an upper surface of the engine head has an engaging recess formed in an inner peripheral surface in the vicinity of an upper end portion of the engine hole portion; The cap portion holds an elastic fixing member fitted from the upper end portion of the cord cap portion to the outer peripheral surface closer to the female plug terminal than the engaging recess, and is disposed corresponding to the engaging recess. Since the receiving claw for engaging the engaging claw portion of the elastic fixing member with the engaging concave portion is provided in a protruding manner, the operation of inserting the high pressure spark plug cap into the engine hole is performed by the cord cap. The fitting work between the lower end surface of the portion and the groove portion engraved on the upper end surface of the elastic cap portion requires only the same effort as the conventional one, and the other fitting work is completed by simply pressing lightly. The engagement of the locking claws Easily confirm completion of the fitted working by engagement sounds for parts.

Further, in the cap for a high-pressure spark plug of the present invention, the rain cover portion has a recessed portion formed therein for receiving the rocking motion of the tip end portion of the elastic arm portion of the elastic fixing member. Therefore, the length of the elastic arm portion can be set to be long, and as a result, the elastic fixing member can be easily attached to and detached from the seat by using the long elastic arm portion.

Further, in the high pressure spark plug cap of the present invention, the cord cap portion projects a locking projection on an outer peripheral surface above the seat, while the elastic fixing member has a cylindrical body portion. Since the engaging groove engageable with the locking projection is provided on the inner peripheral surface of the, the positioning of the elastic fixing member with respect to the engaging recess is accurately performed, and a rotation preventing function is added. .

Further, in the cap for a high-pressure spark plug of the present invention, the cord cap portion is vertically long and can accommodate the lock member so that a part of the lock member can be engaged with the engaging recess on the outer peripheral surface thereof. Since the lock-like storage portion is provided in a protruding manner, the structure of the elastic fixing member is further simplified, and the load of fitting work is reduced. Further, if the lock member is composed of an independent metal spring member, a more metallic engagement sound can be obtained, so that it is easier to confirm the completion of the fitting work.

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the cap for a high pressure spark plug of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view showing a cap 20 for a high pressure spark plug of the present invention applied to a spark plug 4 of an internal combustion engine, and FIG. 2 is an exploded view of a main part of the cap 20 for a high pressure spark plug of FIG. It is the perspective view shown. 3 is a vertical cross-sectional view showing a modified example of the high-pressure spark plug cap 20 of the present invention applied to the spark plug 4 of the internal combustion engine. FIG. 4 shows a main part of the high-pressure spark plug cap 20 of FIG. It is an exploded perspective view.

The cap 20 for a high-pressure spark plug of the present invention shown in FIGS. 1 and 2 is fitted to a cord cap portion 29 formed of an insulating synthetic resin in a substantially cylindrical shape and an upper end portion of the cord cap portion 29. And presses the upper surface 2 of the engine head with the seal lip portion 22 protruding from the outer peripheral edge of the flange,
The rain cover portion 21 through which the high-pressure cord 5 can be inserted through the side surface thereof, and the vicinity of the end portion of the high-pressure cord 5 arranged at the lower end portion of the cord cap portion 29 are closely contacted and gripped from the outer surface by compression deformation. Female plug terminals 34, each of which is formed integrally with the cord fixing portion 35 and is composed of a spring contact 35 which is compressively deformable along the axis A of the high-voltage cord 5.

Furthermore, the cap 20 for the high-pressure spark plug
Is a plurality of engaging recesses on the inner peripheral surface near the upper end of the engine hole 1 which is transparently provided from the upper surface 2 of the engine head.
While recessing 39, the cord cap portion 29, the outer peripheral surface closer to the female plug terminal 34 than the engaging recess 39,
The engaging claw portion 28 of the elastic fixing member 24, which holds the elastic fixing member 24 fitted from the upper end portion of the cord cap portion 29 and is arranged corresponding to the engaging concave portion 40, is formed in the engaging concave portion. A receiving seat 32 is provided so as to be engageable with 39.

As is apparent from FIG. 2, the elastic fixing member 24 includes a cylindrical body portion 25; a plurality of vertically long support plate portions 26 projecting from the outer peripheral surface of the cylindrical body portion 25; Board 26
On the outer peripheral surface of the cylindrical skeleton portion 25 defined by the above, the locking claw portion is raised while being inclined slightly outward from the lower end portion of the outer peripheral surface, and the upper end portion thereof is further outwardly projected.
28; an elastic arm portion 27 that is raised substantially vertically from the upper end portion of the locking claw portion 28; a plurality of vertically long engaging grooves 33 formed on the inner peripheral surface of the cylindrical body portion 25; Each is integrally molded.

On the other hand, the rain cover portion 21 is provided with a concave portion 23 therein for receiving the tip end portion of the elastic arm portion 27 so as to allow rocking movements accompanying the fitting operation. The seal lip portion 22 is provided so as to project on the outer peripheral edge of the flange so as to surround the lower end portion of the recess 23. The seal lip portion 22 can maintain and improve the sealing performance by pressing the inner peripheral surface of the seal lip portion 22 rather than simply pressing the completely flat upper surface 2 of the engine head with its edge. It is valid.

Further, the cord cap portion 29 is the seat
A plurality of vertically elongated locking projections 31 are provided on the outer peripheral surface above 32 corresponding to the plurality of vertically elongated engagement grooves 33 formed on the inner peripheral surface of the cylindrical body portion 25. It is made up of

In the high pressure spark plug cap 20 of the present invention shown in FIGS. 1 and 2 having the above-described structure, first, the elastic fixing member 24 is provided at the upper end of the cord cap portion 29.
While the cylindrical skeleton portion 25 is fitted and the engaging groove 33 is engaged with the locking projection 31, the lower ends of the cylindrical skeleton portion 25 and the support plate portion 26 are received. By abutting on the upper surface of the seat 32, the relative positional relationship between the cord cap portion 29 and the elastic fixing member 24 is determined.

Next, while the high-pressure cord 5 penetrating from the side surface of the cord cap portion 29 is fitted into the cutout portion 30 provided at the upper end portion of the cord cap portion 29, the rain cover portion 21 is arranged above the cord cap portion 29. By fitting it on the end,
The rain cover portion 21 via the cord cap portion 29.
And the elastic fixing member 24 are integrated. Further, when the female plug terminal 34 fixed near the end of the high-voltage cord 5 is arranged at a predetermined position inside the lower end of the cord cap portion 29, the high-pressure spark plug cap 20 of the present invention is provided. The preparation for the fitting operation is completed.

Next, when the high-pressure spark plug cap 20 is inserted from the upper end portion of the engine hole portion 1 toward the plug head 37 of the high-pressure spark plug portion 4 screwed to the bottom portion 3, The lower end surface of the cord cap portion 29 is fitted into the groove portion formed in the upper end surface of the elastic cap portion 38, and as a result, the plug head 37 and the spring contactor.
36 makes elastic contact and completes the electrical connection.

The locking claw portion 28 of the elastic fixing member 24 fitted to the upper end portion of the cord cap portion 29 is parallel to the contact between the plug head portion 37 and the spring contactor 36, and the locking claw portion 28 of the elastic fixing member 24 is attached to the engine. The inner peripheral surface of the upper end portion of the hole portion 1 is slidably contacted and bent inward, and then the engaging recess 39 is engaged to return the bent state to the original point. The elastic arm portion 27, which is connected to the locking claw portion 28, swings and displaces in the radial direction of the engine hole portion 1 in accordance with the change in the bending of the locking claw portion 28. Since it is received, its swinging displacement is not prevented, and the smooth spring action of the locking claw portion 28 is promoted. Although the elastic arm portion 27 can be easily attached to and detached from the cord cap portion 29 by gripping the tip portion thereof, the internal space of the rain cover portion 21 is narrowed due to the design of the rain cover portion 21. In this case, even if the length of the elastic arm portion 27 is shortened or eliminated at all, it does not have a fatal influence on the basic spring operation of the locking claw portion 28.

Further, in the rain cover portion 21, the inner peripheral surface of the seal lip portion 22 presses against the upper surface 2 of the engine head, and the sealing performance around the periphery can be maintained and improved.
Therefore, the operation of inserting the high-pressure spark plug cap 20 into the engine hole portion 1 is performed by fitting the lower end surface of the cord cap portion 29 and the groove portion formed in the upper end surface of the elastic cap portion 38. Only the same effort as in the prior art is required, and other fitting work is completed by simply pressing it lightly, and furthermore, the fitting work is easily completed by the engaging sound of the engaging claw portion 28 with respect to the engaging recess 39. Can be confirmed. The engagement recess 39 may be formed as a continuous groove along the circumferential direction of the inner peripheral surface of the engine hole portion 1.

Another high-pressure spark plug cap 20 of the present invention shown in FIGS. 3 and 4 is a lock formed by bending the outer peripheral surface of the cord cap portion 29 into a substantially V shape instead of the elastic fixing member 24. A vertically long lock storage portion 40 for storing the lock member 43 is provided so that the bent projection of the member 43 can be engaged with the engagement recess 39. The lock accommodating portion 40 is provided with a vertically elongated slit portion 41 which is formed through a bending slit portion of the lock member 43 inserted through an insertion hole 42 formed in an upper end surface of the lock member 43 and faces the engine hole portion 1. The engaging recess 39 is engaged. Therefore, the structure of the elastic fixing member is further simplified, and the load of fitting work is reduced. Further, if the lock member 43 is composed of an independent metal spring material, a more metallic engagement sound can be obtained, so that it is easier to confirm the completion of the fitting work.

[0028]

The cap 20 for a high-pressure spark plug of the present invention constructed as described above has the following novel effects. That is, the cap 20 for a high-pressure spark plug of the present invention is fitted with the cord cap portion 29 formed of an insulating synthetic resin into a substantially cylindrical shape and the upper end portion of the cord cap portion 29, and is fitted to the outer peripheral edge of the flange. The projecting seal lip portion 22 presses the upper surface 2 of the engine head while penetrating the side surface thereof to insert the high pressure cord 5, and the rain cap portion 21 and the cord cap portion.
29 is formed integrally with the cord fixing portion 35 for adhering and gripping the vicinity of the end portion of the high-voltage cord 5 arranged at the lower end of 29 by compression deformation from the outer surface, and to the axis A of the high-pressure cord 5. Each of which is provided with the female plug terminal 34 composed of the spring contactor 36 which is compressively deformable along the engine hole portion 1 which is transparently provided from the upper surface 2 of the engine head in the vicinity of an upper end portion thereof. While the engaging recess 39 is provided on the inner peripheral surface of the cord cap portion 29, the cord cap portion 29 has an upper end portion of the cord cap portion 29 on the outer peripheral surface closer to the female plug terminal 34 than the engaging recess portion 39. The elastic claw 28 of the elastic fixing member 24, which holds the elastic fixing member 24 fitted from above and is arranged corresponding to the engaging concave 39, can be engaged with the engaging concave 39. Since the seat 32 is projected, the engine hole portion 1 The insertion operation of the high-pressure spark plug cap 20, the code cap portion 29 against
The fitting work of the lower end surface of the and the groove portion engraved on the upper end surface of the elastic cap portion 38 requires only the same effort as the conventional one, and the other fitting work is completed by simply pushing lightly,
It is possible to easily confirm the completion of the fitting operation by the engagement sound of the locking claw portion 28 with respect to the engagement recess 39.

Further, the cap for the high pressure spark plug of the present invention
In the rain cover portion 21, the rain cover portion 21 is provided with the concave portion 23 therein, which is capable of receiving the swinging motion of the tip end portion of the elastic arm portion 27 of the elastic fixing member 24. The length of the portion 27 can be set long, and as a result, by using the long elastic arm portion 27, it is possible to easily attach and detach the elastic fixing member 24 to and from the seat 32.

Furthermore, the cap for a high-pressure spark plug of the present invention
In the cord 20, the cord cap portion 29 has the locking protrusion 31 provided on the outer peripheral surface above the seat 33, while the elastic fixing member 24 is provided on the inner peripheral surface of the cylindrical body portion 25. Since the engaging groove 33 engageable with the locking projection 31 is provided as a recess, the elastic fixing member 24 is accurately positioned with respect to the engaging recess 39, and a function to prevent rotation is imparted. It has become possible.

Further, the cap for a high pressure spark plug of the present invention
Reference numeral 20 denotes the vertically long lock storage portion in which the code cap portion 29 can store the lock member 43 on the outer peripheral surface thereof so that a part of the lock member 44 can be engaged with the engagement recess 39.
Since the protrusions 40 are provided, the structure of the elastic fixing member is further simplified, and the load of fitting work can be reduced. Further, if the lock member 43 is composed of an independent metal spring member, a more metallic engaging sound can be obtained, so that it is possible to further easily confirm the completion of the fitting work.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a cap for a high pressure spark plug of the present invention applied to a spark plug of an internal combustion engine.

2 is an exploded perspective view of a main part of the high pressure spark plug cap of FIG. 1. FIG.

FIG. 3 is a vertical cross-sectional view showing a modified example of the cap for a high pressure spark plug of the present invention applied to a spark plug of an internal combustion engine.

FIG. 4 is an exploded perspective view of a main part of the high pressure spark plug cap of FIG. 2.

FIG. 5 is a vertical cross-sectional view showing a conventional cap for a high pressure spark plug applied to a spark plug of an internal combustion engine.

[Explanation of sign] 1 engine hall 2 Top of engine head 3 Bottom of engine hall 4 Spark plug part 5 high-voltage cord 10 Conventional high-pressure spark plug cap 11 Rain cover part 12 Seal lip 13 Cylindrical straight body 14 Cord cap part 15 Cord fixing part 16 half ring 17 Female plug terminal 18 Elastic cap part 20 Cap for high-pressure spark plug of the present invention 21 Rain cover part 22 Seal lip 23 recess 24 Elastic fixing member 25 Cylindrical body part 26 Support plate 27 Elastic arm 28 Locking claw 29 Cord cap part 30 notch 31 Locking ridge 32 seat 33 Engagement groove 34 Female plug terminal 35 Cord fixing part 36 spring contact 37 plug head 38 Elastic cap part 39 Engagement recess 40 Lock compartment 41 Slit section 42 insertion hole 43 Lock member A shaft core

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01T 13/04 F02P 13/00 303 H01T 13/06

Claims (4)

(57) [Claims] 1. An upper surface of an engine head, which includes a cord cap portion formed of an insulating synthetic resin in a substantially cylindrical shape, and a seal lip portion fitted to an upper end portion of the cord cap portion and protruding from an outer peripheral edge of a flange thereof. While pressing, the rain cover portion through which the high-pressure cord can be inserted through the side surface thereof, and the vicinity of the end portion of the high-pressure cord arranged at the lower end of the cord cap portion are brought into close contact by compression deformation from the outer surface, A cap for a high-pressure ignition plug, which is formed integrally with a cord fixing portion to be gripped, and each of which is provided with a female plug terminal formed of a spring contactor which can be compressed and deformed along an axis of the high-voltage cord, The engine hole portion that is transparently provided from the upper surface of the engine head has an engaging recessed portion provided on the inner peripheral surface near the upper end portion thereof, while the code cap portion has a size larger than that of the engaging recessed portion. An elastic fixing member fitted from the upper end of the cord cap portion is held on the outer peripheral surface near the female plug terminal, and a locking claw portion of the elastic fixing member is provided corresponding to the engaging recess. A cap for a high-pressure spark plug, characterized in that it is provided with a receiving seat that can be engaged with the engaging recess. 2. The rain cover portion is provided with a recessed portion therein, which is capable of receiving rocking motion of a tip portion of an elastic arm portion of the elastic fixing member. The high pressure spark plug cap described. 3. The cord cap portion projects a locking ridge on an outer peripheral surface above the seat, while the elastic fixing member is formed on the inner peripheral surface of a cylindrical body portion. The cap for a high-pressure spark plug according to claim 1, wherein an engaging groove that can be engaged with the recess is provided. 4. The cord cap portion has, on its outer peripheral surface, a vertically elongated lock storage portion that can store the lock member so that a part of the lock member can be engaged with the engagement recess. The cap for a high-pressure spark plug according to claim 1, which is made of: