JPH0517405Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a tube gasket that is attached to the end of a tube to maintain airtightness between the tube and a member adjacent thereto. .

[Conventional technology]

Conventionally, one of the tube gaskets described above is a tube gasket that is used between the cylinder head cover of an internal combustion engine and a plug tube through which a spark plug is inserted into the inner cavity, and seals oil scattered inside the head cover from the outside. There is.

This kind of tube gasket is suitable for example
As shown in the figure, it has a structure in which a seal lip 1 made of a rubber material and a mounting portion 2 at its base are integrally vulcanized and bonded to a metal reinforcing ring 3, and a plug tube into which a spark plug (not shown) is inserted is inserted into the inner cavity. The seal lip 1 is fitted onto the outer circumferential surface of the upper end of the plug tube 4 while being positioned by the reinforcing ring 3, and the seal lip 1 is brought into close contact with the lower surface of the cylinder head cover 5 located above the plug tube 4 due to its elasticity. This seals between the cylinder head cover 5 and the plug tube 4.

[Problem that the invention attempts to solve]

However, according to the above-mentioned conventional structure, since the seal depends solely on the elasticity of the rubber material constituting the seal lip 1, the seal lip 1 may suffer from compression set or develop within the cylinder head cover 5 after long-term use. If deterioration occurs due to heat or immersion in scattered oil, there is a risk that the sealing performance will deteriorate.

Furthermore, if there are variations in the distance L between the upper end of the plug tube 4 and the contact surface of the seal lip 1 of the cylinder head cover 5, the surface pressure of the seal lip 1 against the cylinder head cover 5 may be insufficient, or the 4 As shown in Figure 4, seal lip 1
If there are pinholes or machining marks 6 on the abutment surface of the cylinder head cover 5, the sealing performance will inevitably deteriorate because the contact area becomes smaller due to the curling.

In view of these problems, the present invention aims to provide a tube gasket with excellent sealing properties.

[Means for solving problems]

That is, the present invention provides a tube gasket in which the front seal lip of the main body attached to the end of the tube closely seals the tube and a mating member adjacent to the tube, and a spring fixed to a reinforcing ring embedded in the main body. A retainer is provided, and a spring is elastically loaded between the spring retainer and the back surface of the seal lip.

[Effect]

According to the above structure, one end of the spring is supported by the spring holder, and the other end of the spring always presses the seal lip toward the mating member, so if the elasticity of the seal lip decreases for some reason or the tube Even if there is some variation between the seal lip and the mating member, the seal lip will come into close contact with the mating member with sufficient surface pressure due to the biasing force of the spring, and no curling will occur.
The contact area is also relatively large.

〔Example〕

Next, an embodiment of the tube gasket according to the present invention will be described based on the drawings.

In FIG. 1, the tube gasket of this embodiment, generally designated by the reference numeral 11, is used to seal between a plug tube 20 and a cylinder head cover 21 in an internal combustion engine. It has a structure in which a seal lip 13 made of a rubber material and a mounting part 14 are integrally vulcanized and bonded to a substantially L-shaped metal reinforcing ring 15. That is, the main body 12 is fitted onto the outer peripheral surface of the upper end 20a of the plug tube 20 at the mounting portion 14 while being positioned by the inward flange 15a of the reinforcing ring 15.
The seal lip 13 is adapted to come into contact with a cylinder head cover 21, which is a mating member. 16
A spring holder is located on the outer periphery of the rear end (lower end) of the main body 12 and is welded 17 to a reinforcing ring 15. A spring 18 is installed between the spring holder 16 and the seal lip 13 in an appropriately compressed state. ing. A compression ring 19 is bonded to the back surface of the seal lip 13, and the spring 18 presses and urges the seal lip 13 via the compression ring 19 to seal the bottom surface of the cylinder head cover 21. are placed in close contact with each other with sufficient surface pressure and contact area.

According to this configuration, the seal lip 13 is always urged toward the cylinder head cover 21 side by the spring 18 whose one end is supported by the spring retainer 16, so that even if the plug tube upper end 20a and the cylinder head cover Even if there is some error in the distance L between the seal lip 13 and the lower surface, or even if the rubber material constituting the seal lip 13 suffers from compression set due to long-term use, the biasing force of the spring 18 will reduce the surface pressure. and can maintain a sufficient contact area.

In the above embodiment, the spring presser 16 was welded 17 to the reinforcing ring 15, but as shown in FIG.
A structure may also be adopted in which the spring 18 is slidably inserted and tightened and fixed with a set screw 22, and the biasing force of the spring 18 can be adjusted.

[Effect of idea]

As explained above, the tube gasket according to the present invention has a structure in which a spring is attached that constantly presses the seal lip toward the mating member, so that the tube to which the tube gasket is attached and the seal lip of the gasket are attached. Even if there is some variation in the relative positional relationship between the contact member and the mating member with which the contact member is in close contact, the biasing force of the spring follows this variation and ensures sufficient surface pressure, and the contact area is also relatively large. Even if the elasticity of the seal lip decreases due to compression set or the like, the biasing force prevents the surface pressure and contact area from decreasing. Therefore, good sealing performance can be maintained over a long period of time, and even if there are pinholes or machining marks on the contact surface of the mating member with the seal lip, the contact area is large, so these pinholes and It has an excellent effect of preventing leakage through machining marks as much as possible.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an embodiment of the tube gasket according to the present invention in a bonded state, FIG. 2 is a sectional view of essential parts showing a modified example, and FIGS.
The figure is a half-cut sectional view showing an example of a conventional tube gasket in an installed state. 11...Tube gasket, 12...Main body,
13... Seal lip, 14... Mounting part, 15...
... Reinforcement ring, 15a ... Inward flange, 16 ... Spring holder, 17 ... Welding, 18 ... Spring, 19 ... Compression ring, 20 ...
Plug tube, 20a...upper end, 21...cylinder head cover, 22...set screw.

Claims (1)

[Scope of utility model registration request] In a tube gasket in which a seal lip 13 at the front of the main body 12 attached to the end of the tube closely seals a mating member adjacent to the tube, a spring retainer is fixed to a reinforcing ring 15 embedded in the main body 12. 16, and
This spring presser 16 and the seal lip 1
3. A tube gasket characterized by having a spring 18 loaded between it and the back.