JP2001012606A - Structure of preventing coming-off of annular seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the coming-off and dropping-out of an annular seal having an inner peripheral contact part and an outer peripheral contact part which make contact with seal surfaces of a member to be sealed, a bore part through which a shaft part is inserted, for effecting sealing differently between the radially inner part and the radially outer part, during assembling of the seal. SOLUTION: In this structure, the fringing surface of the bore part of an annular seal is provided with a taper 101 which narrows from an inner peripheral contact part 11 toward a diametrically inner part 4 at a peripheral edge surface of a bore of the annular seal, with a taper 101. Accordingly, the coming- off or dropping-out of the annular seal can be prevented during assembling thereof, and further since no interference occurs between the seal and a shaft member upon pressing of the seal, a seal pressing force can be efficiently transmitted to the seal, thereby it is possible to obtain a desired sealing function.

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 the 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. 10, and includes a cylinder head 3 and an injector 2.
It is elastically deformed by being pressed between them, and its restoring force exerts a sealing effect. The dotted line in the figure shows the annular seal when pressed.

[0005] In order to interpose such an annular seal 1 between the injector 2 and the cylinder head 3, first, as shown in FIG. 11, the shaft seal is injected into a shaft-shaped 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. The inner hole 10 and the injection valve 21 as shown in FIG. 12B 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. 12, 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:
To solve the above problems, as shown in FIGS. 1 and 2,
An inner peripheral contact portion 11, an outer peripheral contact portion 12, which is provided between the members to be sealed and abuts the sealing surface of the member to be sealed, and an inner hole 10 through which the shaft member is inserted. In the annular seal 1 that seals while distinguishing the outer side in the direction,
A tapered portion 101 is provided on the peripheral surface of the inner hole portion, and a tapered tip portion 10 of the tapered portion 101 forming the innermost diameter
2, the taper tip 102 is elastically or caught on the outer peripheral edge 211 of the injector 21 of the injector as shown in FIG. 3 so that the injector 21 faces downward. Even if the injector is in the vertical state, the annular seal does not fall. Further, by providing the tapered portion 101, the contact area between the outer peripheral edge 211 and the tapered tip portion 102 can be reduced, the frictional resistance during insertion can be suppressed, and the insertion can be performed smoothly.

As shown in FIG. 4 (a), a tapered portion 101 which narrows from the inner peripheral contact portion 11 toward the radial inner side 4 is provided on the peripheral surface of the inner hole portion 10. 4
As shown in (b), when the seal is deformed by pressing at the time of pressing, the tapered distal end portion 102 that has been in contact with the outer peripheral edge 211 of the injection valve 21 is separated from the injection valve 21, so that pressing is not wasted and the annular seal is not wasted. To achieve a desired sealing effect.

In another embodiment of the present invention, as shown in FIGS. 5 and 6, the inner peripheral contact portion 11, the 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. In the annular seal 1 having an elliptical inner hole 10 through which a shaft member is inserted and performing sealing while distinguishing between a radially inner side and a radially outer side, a threaded portion 23 having a diameter larger than the shaft diameter is provided on the shaft member. Is provided, and the short diameter side of the elliptical inner hole portion and the screw portion 23 interfere with each other and are locked, so that they pass through the screw thread 23 provided in the injection valve 21 of the injector 2. Even if the injector 2 is placed vertically with the injection valve 21 facing downward, the annular seal 1 can be prevented from falling down.

Further, since the minor diameter of the inner hole 10 is slightly smaller than the outer diameter of the screw portion 23, the injection valve 21 has a smaller diameter.
Of the inner hole 10 even when pressed.
Does not come into contact with the injection valve 21.

Furthermore, since the annular seal is made of a seal body coated with a coating, the injection valve 21 is not damaged and the injection valve 21 and the annular valve are formed by utilizing the elastic force of the coating. The seal 1 can be engaged, and the coating improves the adhesion of the sealing surface, so that an annular seal with a falling-off prevention structure having excellent sealing properties can be obtained.

In still another embodiment of the present invention, as shown in FIGS. 7 and 8, an inner peripheral contact portion 11, which is provided between the members to be sealed and contacts the sealing surface of the member to be sealed, and an outer peripheral contact portion. The annular seal 1 has a portion 12 and an inner hole portion 10 through which a shaft member is inserted, and performs sealing while distinguishing between a radially inner side and a radially outer side. The coating pool 61 is provided with a notch 103 on the peripheral surface of the inner hole 10 provided in the seal body 8 on the side of the inner peripheral contact portion 11 in the thickness direction. Since it is provided near the portion and is locked to the shaft member by the coating pool portion 61, 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 falling off and falling. When further pressed, the annular seal 1
Is deformed, the coating pool portion 61 is elastically crushed, and the notch portion 103 is
0 is provided on the inner peripheral contact portion 11 side in the thickness direction of the peripheral surface of the cylindrical seal 0 so that the inner hole 10 and the injection valve 21 do not interfere with each other, and the pressing force can be reduced without waste. Is transmitted to

Further, an inner peripheral contact portion 11, an outer peripheral contact portion 12, which is provided between the members to be sealed and comes into contact with the sealing surface of the member to be sealed, and an inner hole portion 10 through which the shaft member is inserted. In the annular seal 1 that performs sealing by distinguishing between the inner side and the outer side in the radial direction, the inner peripheral locking surface 92 that contacts the outer peripheral edge 211 of the shaft member and the outer peripheral locking that contacts the peripheral surface of the inner hole portion 10. A tightly-fitting cylindrical portion 91 having a surface 93; and a stepped portion 94 extending in an outer radial direction from one end of the tightly-fitted cylindrical portion 91. Drop prevention member 9 whose diameter is larger than the inner diameter of the inner hole of the annular seal.
As shown in FIG. 14, the drop stop member 9 tightly locked in the inner hole 10 of the annular seal 1 is provided with the injection valve 21.
And the annular seal 1 can be reliably prevented from falling.

Further, as shown in FIG. 13 (b), since the drop stop member 9 is tightly locked in the inner hole 10, the annular seal 1 and the drop stop member 9 are integrated into In addition, handling during assembly becomes easy.

[0018]

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 an annular seal according to the first and second embodiments of the present invention, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. FIG. 4 is a view showing a process of deformation of the annular seal of the present invention at the time of pressing.

In the annular seal shown in FIGS. 1 to 4, 1 is an annular seal 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.

Returning to FIG. 2, the inner hole portion 10 is opened so that the injection valve 21 of the injector 2 can be inserted, and a tapered portion 101 is formed on the peripheral surface thereof from the inner peripheral contact portion 11 side. , Are provided so as to narrow toward the inner side 4 in the radial direction. When the annular seal 1 is inserted into the injection valve 21, the tapered end portion 102 of the tapered portion 101 comes into contact with the outer peripheral edge 211 of the injection valve 21. However, the annular seal 1 does not fall off or fall.

Also, at the time of pressing, as shown in FIG.
The annular seal 1 is held so as not to drop in a state in which the annular seal 1 is in contact with the outer peripheral edge 211. However, as shown in FIG. 4B, when a pressure is applied, the annular seal 1 is deformed. As a result, since the distal end portion 102 is separated from the outer peripheral edge 211, the pressing force is transmitted to the annular seal without waste,
The desired sealing performance can be achieved.

FIG. 5A is a top view of the annular seal according to the third embodiment of the present invention, and FIG. 5B is a sectional view taken along the line BB of FIG. 5A. FIG. 6 is a view showing a state where the annular seal is assembled to the injector. 5A and 5B, the annular seal 1
Has an inner peripheral contact portion 11 and an outer peripheral contact portion 12, as in the first and second embodiments of the present invention, but the shape of the inner hole portion 10 is elliptical. As shown in FIG. 6, a screw is attached to the injection valve 21 of the injector 2.
With the pitch cut more than the pitch, the relationship between the outer diameter of the screw and the shorter diameter of the inner hole portion 10 is such that they slightly overlap each other.

To mount the annular seal 1 and the injector 2, the injection valve 21 is inserted into the inner hole 10 and the screw 2
At 3, the annular seal 1 is rotated and loosely fitted. At this time, the outer diameter of the screw portion 23 and the shorter diameter of the inner hole portion 10 overlap, and the outer diameter and the inner hole portion 10 do not overlap with each other. Because it does not overlap with the long diameter of the shaft, moderate play occurs, and the entire annular seal is on the shaft,
It is possible to change the direction in a direction parallel to the pitch direction of the screw, and it is possible to advance while rotating the screw portion 23 while maintaining the shape. After the loose fit, since the screw portion 23 and the inner hole portion 10 overlap, the annular seal 1 does not fall off or fall even when the injection valve 21 is turned downward as shown in FIG.

Further, if the annular seal 1 is deformed when it is assembled to the cylinder head 3 and pressed when it is loosely fitted to the injector 2, the short diameter of the inner hole 10 is
Since the inner diameter of the inner hole 10 is larger than the shaft diameter, the inner hole 10 and the injection valve 21 do not interfere with each other.

Although the inner hole 10 has an elliptical shape here, it may have an oval shape as long as the screw 23 and the portion where the inner hole 10 overlaps and a portion where a gap is formed are mixed. Also, in order to make it easy to generate moderate backlash,
The pitch of the threaded portion 23 is preferably large. Also,
The number of pitches is preferably at least one pitch, and may be more than one pitch. However, in order to facilitate attachment and detachment of the annular seal, about 1-2 pitches are preferable.

FIG. 7 is a diagram showing the annular seal 1 according to the fifth embodiment of the present invention engaged with the injection valve 21.
FIG. 8 is an enlarged view of a portion C in FIG. In FIG. 7, the annular seal 1 has an inner peripheral contact portion 11 and an outer peripheral contact portion 1 as in the first and second embodiments of the present invention.
2, a perfect circular inner hole 10 is provided. As shown in FIG. 8, a notch 103 having a concave shape is provided on the inner peripheral contact portion 11 side of the peripheral surface of the inner hole 10, and the surface of the seal body 8 is coated with the coating layer 6. Since the coating agent concentrates on the notch 103,
Is formed as shown in FIG.

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 to 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. 8, the cross section of the notch 103 has a stepped shape, but the corner of the peripheral surface of the inner hole 10 on the side of the inner contact portion 11 is largely chamfered. The shape is not particularly limited as long as the shape is concave from the corner.

The presence or absence of a coating is not a problem for the annular seals according to the first to third aspects, but by applying the annular seals, an annular seal having a structure for preventing falling off and having excellent sealing properties can be obtained. . In this case, the annular seal refers to a seal body having a coating applied thereto. Further, by applying the coating to the embodiments shown in claims 1 and 2, the coating is performed without damaging the shaft member. The annular seal can be engaged with the shaft member by utilizing the elastic force of the above.

FIG. 13 is a view showing a fall prevention member 9 according to an embodiment of the present invention in claim 6, and a view in which the fall prevention member 9 is assembled to the annular seal 1. FIG. The fall prevention member 9 has a cylindrical shape with a flange formed of resin or rubber. The fall-stopping member 9 is such that the tightly fitted cylindrical portion 91 has the annular seal 1.
Is tightly locked to the inner hole portion 10 from the radial inner side 4, and the outer circumferential locking surface 93 abuts on the peripheral surface of the inner hole portion 10 to be integrated with the annular seal 1. The annular seal 1 is tightly locked by press-fitting. For example, if the inner diameter of the inner hole 10 is D1, the outer diameter of the outer locking surface 93 is D2, and the inner diameter of the inner locking surface 92 is D3, D3 = 15. In the case of (mm) or less, it is preferable that D2 is larger than D1 by about 0.05 to 0.5 (mm), but it may be appropriately determined according to the strength and elongation of the material used. For example, when the material of the drop stop member 9 is PTFE-based resin, D2 is 0.05 to
It is preferable to increase the thickness by about 0.15 (mm).

When the annular drop stopper 9 integrated with the annular seal 1 is assembled to the injector 2, it can be handled as a single item by a handling machine or the like.
As shown in FIG. 4, it is pressed into the injection valve 21 as it is,
The inner peripheral locking surface 92 is mounted in contact with the outer peripheral edge 211 of the injection valve 21. As an example, assuming that the outer diameter of the injection valve 21 is D4, it is preferable that D3 be smaller than D4 by 0.05 to 0.5 (mm). For example, when the material of the drop stopper 9 is PTFE , D3 is 0.05 more than D4
It is preferable to reduce the size by about 0.2 (mm).

Also, even after the injection valve 21 is turned downward as shown in FIG. 14 after being assembled to the injector 2, the fall-stop member 9 does not fall down in close contact with the injection valve 21.
As shown in FIG. 3, since the outer diameter of the outer peripheral edge 95 of the drop stopper 9 is larger than the inner diameter of the inner hole 10, the annular seal 1
Is configured to be caught by the drop stop member 9, and even when the press-fitting of the close fitting cylindrical portion 91 into the inner hole portion 10 is weak,
It does not drop due to contact or vibration during transfer.

It is preferable to use a resin or rubber having a high elastic force as a material used for the drop stopper 9.
By using PTFE, after assembling the annular seal 1, pressing is applied, and when the annular seal 1 is deformed,
The fall prevention member 9 interposed between the outer peripheral edge 211 of the injection valve 21 and the peripheral surface of the inner hole portion 10 does not affect the sealing performance of the annular seal 1 during compression.

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.

[0036]

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 the annular seal of the present invention.

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 of the present invention when pressed.

FIG. 5 is a view showing an annular seal according to claim 3 of the present invention.

FIG. 6 is a view showing a state at the time of assembling an annular seal according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing an annular seal according to claim 5 of the present invention.

FIG. 8 is an enlarged view of a portion C in FIG. 7;

FIG. 9 is a view showing a state after a conventional annular seal is assembled.

FIG. 10 is a view showing a conventional annular seal.

FIG. 11 is a diagram showing a state when a conventional annular seal is assembled.

FIG. 12 is a cross-sectional view showing a deformation process of a conventional annular seal when pressed.

FIG. 13 is a view showing an annular seal and a fall prevention member according to claims 6 and 7 of the present invention.

FIG. 14 is a view showing a state in which the annular seal and the stopper member according to the sixth and seventh aspects of the present invention are assembled.

[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 body 9 Fall prevention member 10 Inner hole 11 Inner peripheral contact part 12 Outer peripheral contact part 21 Injection valve 22 Injector seal surface 23 Screw part 31 Opening part 32 Cylinder head sealing surface 61 Coating pool part 91 Close fitting cylindrical part 92 Inner circumference locking surface 93 Outer circumference locking surface 94 Stepped part 95 Outer peripheral edge 101 Tapered part 102 Tapered tip part 103 Notch part 211 Outer edge

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuyuki Nishimura 663 Minoshima, Arita-shi, Wakayama F-term in Mishima Works, Mitsubishi Cable Industries, Ltd. (reference) 3J040 AA01 AA12 AA17 BA01 EA15 EA18 EA48 FA01 FA05 HA03 HA05 HA15

Claims (7)

[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. In the annular seal that seals by distinguishing the outer side from the radial direction, a tapered portion is provided on the peripheral surface of the inner hole portion, and the tapered tip portion of the tapered portion forming the innermost diameter is engaged with the shaft member. A structure for preventing the annular seal from falling off. 2. The fall prevention of an annular seal according to claim 1, wherein a tapered portion narrowing from the inner peripheral contact portion side to the radially inner side is provided on a peripheral surface of the inner hole portion. Construction. 3. An outer peripheral abutting portion, an outer peripheral abutting portion, which is provided between the members to be sealed and abuts a sealing surface of the member to be sealed, and an elliptical inner hole through which a shaft member is inserted. In an annular seal that performs sealing by distinguishing between a direction inner side and a radially outer side, a screw portion having a diameter larger than a shaft diameter is provided on the shaft member, and a shorter diameter side of the elliptical inner hole portion, and the screw portion. A structure for preventing the annular seal from falling off, which interferes with and locks. 4. The seal according to claim 1, wherein said annular seal comprises a seal body coated.
4. The structure for preventing the annular seal from falling off according to any one of the above items 3 to 3. 5. A radially inner side, which is provided between the members to be sealed and has an inner peripheral contact portion, an outer peripheral contact portion that contacts the sealing surface of the member to be sealed, 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. . 6. A radially inner side, which is provided between the members to be sealed and has an inner peripheral contact portion and an outer peripheral contact portion that contact the sealing surface of the member to be sealed, and an inner hole through which the shaft member is inserted. In the annular seal that seals while distinguishing the outer side in the radial direction from the outside, a drop-stopping member provided with an inner peripheral locking surface that is tightly locked to the shaft member and an outer peripheral locking surface that is tightly locked to the annular seal is provided. A structure for preventing the annular seal from falling off, wherein the annular seal is prevented from falling. 7. A radially inner side, which is provided between the members to be sealed and has an inner peripheral contact portion, an outer peripheral contact portion that contacts the sealing surface of the member to be sealed, and an inner hole through which the shaft member is inserted. A tight seal cylinder comprising an inner peripheral locking surface that abuts the outer peripheral edge of the shaft member and an outer peripheral locking surface that abuts the peripheral surface of the inner hole portion in the annular seal that performs sealing while distinguishing the outer side from the radial direction. Portion, and a stepped portion extending in the outer diameter direction from one end of the close fitting cylindrical portion, the outer diameter of the outer peripheral edge of the stepped portion is larger than the inner diameter of the inner hole of the annular seal. A structure for preventing the annular seal from falling off, wherein a large diameter stopper is provided to prevent the annular seal from falling.