JP3356740B2 - Structure to prevent falling off of annular seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to
Also, the present invention relates to a structure for preventing the annular seal from falling off from the shaft member during maintenance work or the like.

[0002]

2. Description of the Related Art It is well known to use a sealing member to seal an inner space and an outer space in forming a sealing device of a hydraulic or pneumatic system.

[0003] The same applies to an internal combustion engine, in which fuel is directly injected into a cylinder of the internal combustion engine, and a seal is used for an injector attached to a cylinder head. As shown in FIG. An annular seal is used between the cylinder head 3 and the injector 2 to prevent leakage. The annular seal 1 used between the cylinder head 3 and the injector 2 must be a seal capable of withstanding severe conditions,
A metal material with mechanical strength against heat and vibration, as well as mechanical strength that can withstand high pressure and high temperature due to combustion gas in the cylinder is used, and on the surface, improve the adhesion of the sealing surface, Coatings may be applied to improve sealing performance.

The annular seal 1 has a shape as shown in FIG. 8, and is elastically deformed by being pressed between the cylinder head 3 and the injector 2, and exerts a sealing effect by its restoring force. The dotted line in the figure shows the annular seal when pressed.

In order to interpose such an annular seal 1 between the injector 2 and the cylinder head 3, first, as shown in FIG. 9, an injection is applied to an axial injection valve 21 existing at the tip end of the injector 2. The annular seal 1 having the inner hole 10 having a diameter larger than the shaft diameter of the valve 21 is attached by inserting the viscous grease 7 in a state of being applied thereto. Next, in order to insert the injector 2 with the annular seal 1 into the opening 31 provided in the cylinder head 3, the injection valve 21 of the injector 2 is inserted in the vicinity of the opening of the cylinder head 3 so as to face downward, and is pressed. , Fix. When inserting the injection valve 21 downward, the annular seal 1 attached to the injection valve 21 adheres to the outer peripheral edge 211 of the injection valve 21 due to the viscosity of the grease 7, so that the annular seal 1 does not drop or fall. Has become.

Further, since the grease 7 prevents falling and falling, the diameter of the inner hole 10 of the annular seal 1 can be made relatively large. As shown in FIG. 10B, the inner hole 10 and the injection valve 21 did not interfere with each other, and as a result, the sealing performance did not decrease.

[0007]

However, the conventional annular seal 1 prevents the annular seal 1 from dropping and dropping from the injector 21 of the injector by the viscosity of the grease 7 when the injector 2 is assembled. Therefore, in an environment in which the temperature rises, such as in summer, the viscosity may be impaired, and the annular seal 1 may drop or fall.

Further, the diameter of the inner hole 10 of the annular seal 1 is set to be slightly larger than the diameter of the injector 21 of the injector so that the viscousness of the grease 7 acting to prevent the grease 7 from dropping off and falling is minimized. In this case, as shown in FIG. 10, when the seal is pressed, the inner hole portion 10 and the injection valve 21 interfere with each other, so that the expected pressing force cannot be obtained on the seal, and as a result, the target sealing performance cannot be obtained. Then, the injector 21 of the injector may be damaged, and the original performance of the injector may be impaired.

The present invention has been made to solve this problem, and prevents the annular seal from falling off and dropping during the assembling work, so that the seal and the shaft member do not interfere with each other at the time of pressing.
An object of the present invention is to provide a structure for preventing an annular seal from falling off, which can achieve a desired sealing characteristic.

[0010]

Means and Action for Solving the Problems That is, the present invention provides:
In order to solve the above problems, in the present invention, FIG.
As shown in FIG. 6, an inner peripheral contact portion 11, an outer peripheral contact portion 12, which are provided between the members to be sealed and come into contact with the sealing surface of the member to be sealed, and an inner hole 10 through which the shaft member is inserted. An annular seal 1 that seals a radially inner side and a radially outer side separately, wherein the annular seal 1 is formed by coating the surface of a seal body 8, and the inner hole provided in the seal body 8. The coating pool 61 is provided in the vicinity of the notch by providing the notch 103 on the inner peripheral contact portion 11 side in the thickness direction of the peripheral surface of the portion 10, and the coating pool 61 is used for the shaft member. Since the locking is characteristic, the coating is locked to the injection valve 21 by the elastic force of the coating, so that the annular seal 1 can be prevented from dropping and falling. Further, even when the annular seal 1 is deformed, the coating pool 61 is elastically crushed even if the annular seal 1 is deformed, and the notch 103 is formed by the notch 103 in the thickness direction of the peripheral surface of the inner hole 10 in the inner circumferential direction. Since the contact portion 11 is provided in a concave shape, the pressing force is transmitted to the annular seal 1 without waste without the inner hole portion 10 and the injection valve 21 interfering with each other.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a top view of the annular seal, and FIG.
FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is a view showing a state at the time of assembly, and FIG. 4 is a view showing a process of deformation of the annular seal at the time of pressing.

In the annular seal shown in FIGS. 1 to 4, 1 is an annular seal main body, 10 is a perfect circular inner hole,
Denotes an inner peripheral contact portion, and 12 denotes an outer peripheral contact portion. Annular seal 1
As shown in FIG. 2, one side of the cross section is substantially S-shaped, and the ridges are an inner peripheral contact portion 11 and an outer peripheral contact portion 12, which are interposed between the injector 2 and the cylinder head 3. When the pressing force is applied, as shown in FIG. 4B, the inner peripheral contact portion 11 comes into contact with the injector seal surface 22 of the injector 2 and the outer peripheral contact portion 12 comes into contact with the cylinder head of the cylinder head 3. Since the entire annular seal is abutted against the sealing surface 32 and elastically deforms, the restoring force acts on the abutting surface, and the abutting surface exerts a sealing effect, so that the radial inner portion 4 and the radial outer portion 5 can be separately sealed. It has become.

FIG. 5 is a view in which the annular seal 1 according to the present invention is engaged with the injection valve 21, and FIG. 6 is an enlarged view of a portion C in FIG. In FIG. 5, the annular seal 1 of the present invention
Includes an inner peripheral contact portion 11, an outer peripheral contact portion 12, and a perfect circular inner hole portion 10. Also, as shown in FIG.
On the inner peripheral contact portion 11 side of the peripheral surface of No. 0, a notch 103 having a concave shape is provided, and the surface of the seal body 8 is covered with the coating layer 6. Since the coating agent concentrates, a coating reservoir 61 as shown in FIG. 6 is formed.

When the annular seal 1 is mounted on the injection valve 21 of the injector 2, the coating pool 61 abuts on the outer peripheral edge 211 of the injection valve 21 as shown in FIG. Will be retained.

Even if the annular seal 1 is deformed by being assembled with the cylinder head 3 while being engaged with the injector 2, the notch 103 has a concave shape. The part 10 and the injection valve 21 do not interfere.

Here, in FIG. 6, the shape of the notch 103 has a stepped cross section. However, the corner of the peripheral surface of the inner hole 10 on the side of the inner peripheral contact portion 11 is largely chamfered. The shape is not particularly limited as long as the shape is concave from the corner.

Here, the material used for the annular seal 1 is thermally, chemically, or
The mechanically unstable material is, of course, not particularly limited as long as it is an elastic member, but is preferably a metal material, particularly, a stainless steel or a spring steel in order to require a restoring force against pressing. preferable. Also, the coating material is not particularly limited as long as it is a softener such as rubber or resin, and may be appropriately determined according to the use conditions.

[0017]

According to the structure for preventing the annular seal from falling off according to the present invention as described above, it is possible to eliminate the possibility that the annular seal has fallen off the shaft member and dropped during the assembling operation. In addition, when the seal is pressed, the seal and the shaft member do not interfere with each other, so that the seal performance does not decrease and the target seal performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a top view of an annular seal.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a diagram showing a state at the time of assembly.

FIG. 4 is a cross-sectional view showing a deformation process of the annular seal when pressed.

FIG. 5 is a sectional view showing an annular seal of the present invention.

FIG. 6 is an enlarged view of a portion C in FIG. 5;

FIG. 7 is a view showing a state after assembly of a conventional annular seal.

FIG. 8 is a view showing a conventional annular seal.

FIG. 9 is a diagram showing a state when a conventional annular seal is assembled.

FIG. 10 is a cross-sectional view showing a deformation process of a conventional annular seal when pressed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Annular seal 2 Injector 3 Cylinder head 4 Radial inside 5 Radial outside 6 Coating layer 7 Grease 8 Seal main body 10 Inner hole 11 Inner peripheral contact part 12 Outer peripheral contact part 21 Injection valve 22 Injector seal surface 31 Opening 32 Cylinder head sealing surface 61 Coating pool 101 Tapered portion 102 Tapered tip 103 Notch 211 Outer edge

Continuation of the front page (56) References JP-A-9-112697 (JP, A) JP-A-6-241218 (JP, A) JP-A-11-200991 (JP, A) Jpn. , U) Actually open 60-37615 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16J 15/08

Claims (1)

(57) [Claims] An inner contact portion provided between the sealed members and in contact with a sealing surface of the sealed member; an outer contact portion; and an inner hole through which the shaft member is inserted. The seal is made by coating the surface of the seal body, and the inner surface of the inner hole provided in the seal body has a thickness in the thickness direction. A notch portion is provided on the peripheral contact portion side to provide a coating pool portion near the notch portion, and the coating pool portion is locked to the shaft member, thereby preventing the annular seal from falling off. .