JP2000193092A - Packing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packing to facilitate mounting and provide stable sealing ability even when the press force of a press member is a low load and be excellent in reliability. SOLUTION: A main seal part 2 making contact with an inner peripheral side B1 is provided and a taper surface 2a protrusion to the opening side of which is increased toward the inner peripheral side B1 and making contact with a plate C is formed on the opening side of a main seal part 2. A fall of a packing 1 toward the inside diameter side is prevented from occurring and the packing 1 is easily mounted in an annular groove M. Further, sealing ability against the plate C and the inner peripheral side B1 of the annular groove M is provided even when a press force of the plate C is a low load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packing used for sealing a combined gap of a case such as an ignition coil mounted on an engine.

[0002]

2. Description of the Related Art Conventionally, as this type of packing, FIG.
The following are known.

The packing 100 is attached to an annular groove M provided in a combined case of two members such as an ignition coil for generating a high voltage in order to cause an electric spark to flow from a spark plug of an engine or the like. To prevent leakage of the fluid to be sealed such as epoxy resin sealed in the inside O from the gap N to the outside P.

For example, as shown in FIG. 3, the case is constructed by simply assembling a cylindrical case B in a direction indicated by an arrow with a cylindrical case B in contact with the step A2 on a case A having two steps A1 and A2 as shown. The annular groove M has both side surfaces and a bottom surface formed by the step wall surface A3 and the step A1 portion of the case A and the inner peripheral side surface B1 of the case B.
The plate C is attached inside the case.

[0005] The case A and the case B are made of resin. When distortion or the like of the resin occurs due to vibration or heat, the position of the connected and fixed spark plug is affected and the function is deteriorated. It was necessary to prevent the occurrence of distortion and the like by sealing the case A and the case B by enclosing them in the interior O.

The epoxy resin cures from the liquid state to fix the case A and the case B. When the epoxy resin is in the liquid state, the epoxy resin leaks out of the gap N between the case A and the case B. It was arranged in the annular groove M.

The packing is used to position the plate C so that errors in the length of the plate C can be absorbed. Further, since the condition in which this case is used is a high temperature of a maximum of 150 ° C., the length deformation due to the thermal expansion of the plate C mounted in the case is absorbed by the packing.

FIG. 4 shows the packing and the structure thereof will be described in detail. The packing 100 is annular, and includes a seal body 101 which completely enters the annular groove M of the case, and a plate C which pushes the seal body 101 into the annular groove M. And a guide 102 protruding inward.

The seal body 101 has an inner peripheral side formed into a cylindrical flat surface, and has an annular seal portion 103, 1 on the outer peripheral side which abuts against and seals the inner peripheral side surface B1 of the case B which is the side surface of the annular groove M.
04,105.

The annular seal portion 103 is provided at the front end in contact with the bottom surface (step A1) of the annular groove M. The annular seal portion 104 has the highest sealability with the case B. The annular seal portion 105 is provided so that the guide 102 is continuous on the inner diameter side and the plate C is in contact with the annular seal portion 105.

The packing 100 first has a structure shown in FIG.
After being attached to case A as shown in FIG.
As shown in FIG. 5B, the case B is assembled to the case A from the direction of the arrow shown in the figure, and the packing 100 is arranged in the annular groove M as shown in FIG.

Then, the plate C is pushed into the annular groove M in which the packing 100 is arranged, and the plate C comes into contact with the annular seal portion 105 of the packing 100.

When the plate C is further pushed into a predetermined positioning position, the state shown in FIG.
00 is also pushed into the annular groove M and compressed, and the annular seal portions 103, 104, and 105 exhibit sealing properties, seal the annular grooves M of the case A and the case B, and seal the interior O with an epoxy resin or the like. It seals fluid and prevents intrusion of dust and the like from the outside P into the inside O via the gap N.

[0014]

However, in the above-mentioned prior art, the packing 100 is simply compressed when the plate C is pushed in.
Has a high repulsive load, adversely affects the positioning of the plate C, and may deteriorate various functions.

When the plate C is forcibly pushed into the positioning position, an excessive pushing load is applied to the packing 100, and the packing 100 may be damaged.

Further, since the repulsive load of the packing 100 is high, a sufficient sealing property of the packing 100 cannot be obtained unless a sufficient load is applied to the packing 100 by pushing the plate C. The strength and insertability of the supporting resin parts and the like are poor, and increasing the load may rather damage the resin parts and the like supporting the plate C.

Then, after the packing 100 is attached to the case A as shown in FIG. 6A, the case A and the case B are combined, so that as shown in FIG.
When the case A and the case B are combined, the annular seal portion 104 as the main seal portion may be pulled by the case B, the packing 100 may be deformed, and the guide 102 may be inclined to the outer diameter side.

If the guide 102 is tilted in this way, as shown in FIG. 6C, when the guide 102 is pushed by the plate C, the guide 102 is bitten by the plate C,
The plate C does not come into contact with the annular seal portion 105.

Then, the packing 100 receives all the pushing force of the plate C by the annular seal portion 104, and the pushing force of the plate C does not reach the annular seal portion 103, so that the sealing property of the packing 100 is deteriorated.
The bitten guide 102 may be damaged.

An object of the present invention is to solve the above-mentioned problems of the prior art.
An object of the present invention is to provide a highly reliable packing that can be easily mounted and exhibits stable sealing performance even when the pressing force of the pressing member is low.

[0021]

In order to solve the above-mentioned problems of the prior art, according to the present invention, an annular groove formed in combination is arranged, and is pushed in from the opening side of the annular groove by a pressing member to form an annular groove. In the packing which is compressed and sealed in the groove, the annular groove has one wall surface, the other wall surface shorter than the axial length of the packing, and a bottom surface connecting the both wall surfaces, and a main seal abutting on one wall surface of the annular groove. And a slope that projects toward the opening toward the one wall surface of the annular groove and is in contact with the pressing member on the opening side of the main seal portion.

Accordingly, it is possible to prevent the packing from falling down to the other wall surface side of the annular groove due to the pressing member first abutting on the projecting side of the inclined surface, and the compression ratio of the main seal portion is set to one wall surface of the annular groove. The side is raised, and the sealing property with respect to one wall surface of the pressing member and the annular groove can be realized even when the pressing force of the pressing member is low.

An annular seal portion abutting on one wall surface of the annular groove, a thin wall between the annular seal portion and the main seal portion, and buckling preventing means for preventing buckling of the thin portion. It is preferable to provide them.

This reduces the force required for pushing the pressing member by reducing the wall thickness, enables the packing to be pushed with a low load, and prevents the thin portion from buckling with a simple force. can do.

[0025] It is preferable that a flexible portion is provided which is in contact with the bottom surface of the annular groove and which flexes in a direction different from the pushing direction of the pushing member when the pushing force of the pushing member becomes a predetermined value or more.

Accordingly, when the load due to the pushing force by the pressing member is equal to or more than a predetermined value, the flexible portion is bent, and the packing does not require any additional load for sealing.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

In this embodiment, the same reference numerals are given to those described in the related art, and the description is omitted. FIG.
Fig. 2 shows a packing according to an embodiment of the present invention, and Fig. 2 shows a mounted state of the packing.

As shown in FIG. 2, this packing 1 is attached to an annular groove M of a case as described in the prior art, and a fluid to be sealed such as an epoxy resin sealed inside O through a gap N of the case. Is prevented from leaking to the outside P.

The annular groove M is formed by assembling a cylindrical case B in the axial direction indicated by an arrow in a case A having two steps A1 and A2 on the outer peripheral side illustrated in FIG. Provided in the case.

The case A has a step wall A4 substantially equal to the inner diameter of the case B to be assembled and a step wall A3 serving as a side surface of the annular groove M. The step wall A4 is interposed via the step A2. And is continuous with the outer peripheral side surface, and is continuous with the step wall surface A3 via the step A1. The case B comes into contact with the step A2 while being guided by the step wall surface A4 of the case A on the inner peripheral side surface B1.

In this way, the inner wall O of the case B and the inner peripheral side surface B1 of the case B are formed by the step wall A3 whose axial length is shorter than the packing 1 and the bottom (hereinafter referred to as the bottom A1) which is the step A1. Is formed, and an elongated annular groove M which is opened in the axial direction is formed.

The packing 1 is disposed in the annular groove M,
The annular groove M is pressed and compressed by the cylindrical plate C as a pressing member from the opening side opened in the axial direction of the annular groove M to seal the annular groove M.

Next, the packing 1 will be described in detail. The packing 1 includes a main seal portion 2 that contacts the inner peripheral side surface B1 of the case B on the opening side of the annular groove M, An annular seal portion 3 abutting on the inner peripheral side surface B1 of the case B on the bottom surface A1, a plurality of annular protrusions 4 abutting on the stepped wall surface A3 of the case A, and the bottom surface A1 side of the annular seal portion 3 and the annular protrusion 4 A flexible portion 5 which is thin and extends on the bottom surface A1 of the annular groove M and whose outer peripheral side is reduced in diameter toward the distal end.

The main seal portion 2 comes into contact with the plate C at the tapered surface 2a on the opening side of the annular groove M, and the case B
Abuts against the inner peripheral side surface B1 of the base member with a seal allowance having a predetermined width in the axial direction,
It exhibits a high sealing property to the inner peripheral side surface B1.

The surface of the main seal portion 2 which is in contact with the plate C on the opening side of the annular groove M is a tapered surface 2a which is an inclined surface protruding in the opening direction of the annular groove M from the axis toward the outer diameter side. Has become.

Here, the end surface of the plate C which is in contact with the tapered surface 2a is a surface perpendicular to the axial direction.
The taper angle formed between a and the end face of the plate C is, for example, 1
It is provided at 0 degrees or the like.

A protrusion 2b is provided on the inner peripheral side of the tapered surface 2a. The projecting portion 2b has a tapered surface 2a.
It projects in the opening direction of the annular groove M equal to the projecting position most protruding toward the opening side of the annular groove M on the outer diameter side, and projects more inwardly than the plurality of annular projections 4, and a part of the cross-sectional shape shows a circle ing.

The annular projection 2b does not contact the step wall A3 of the case A, but the inner space O on the inner diameter side
Is covered with a fluid to be sealed such as an epoxy resin sealed in the inside. When the tapered surface 2a of the packing 1 comes into contact with the end face of the plate C, the annular projecting portion 2b projects toward the inner diameter side of the plate C, so that it does not come into contact with the end face of the plate C.

The annular seal portion 3 is formed on the inner peripheral side surface B of the case B.
The axial width of the seal allowance is smaller than the predetermined width of the seal allowance of the main seal portion 2 abutting on 1. This allows
When the packing 1 is pushed into the annular groove M, the annular seal portion 3
Does not cause a large resistance even when it comes into contact with the inner peripheral side surface B1, and the packing 1 can be easily mounted.

On the other hand, a burglar 6 is formed between the main seal portion 2 and the annular seal portion 3 on the outer peripheral side of the packing 1, and the packing 1 in the axial direction between the main seal portion 2 and the annular seal portion 3 is formed.
Is thinner. Further, in order to prevent the thin portion in the axial direction between the main seal portion 2 and the annular seal portion 3 from buckling due to an easy force, the rib 7 serving as a buckling prevention means forms a burglar 6. Eight are provided at equal intervals in the circumferential direction.

The number and location of the ribs 7 are not limited as long as buckling is prevented even if they are not provided.

Further, on the outer peripheral side, three annular projections 4 of the same size are arranged in the axial direction on the inner peripheral side of the axial portion where the thickness 6 is provided from the annular seal portion 3.

The annular projection 4 is provided to reduce the volume of the packing 1 and to improve the sealing performance on the step wall A3 of the case A.

Of the three annular projections 4, the annular projection 4 closest to the bottom surface A1 of the annular groove M is disposed at a position directly opposite to the annular seal portion 3, so that even if the packing 1 is compressed with a low load, the annular projection 4 is annular. Both wall surfaces of the groove M are sealed.

In addition, although the volume of the packing 1 itself becomes large, sealing may be performed on the step wall A3 of the case A on a plane on which the annular projection 4 is not provided. Without limitation, the amount of crushing for the seal must be the same.

As described above, considering the load applied to the packing 1, it is better that the number of the annular projections 4 is small, but the amount of movement when the packing 1 is compressed by the plate C and moves in the axial direction is determined by the amount of pushing of the plate C. In this embodiment, it is necessary to avoid the influence on the sealing property of the step wall A3 caused by the variation of the pushing amount of the plate C. In the present embodiment, three continuous annular projections 4 are provided in the axial direction.

The flexible portion 5 has a certain degree of rigidity, has a tongue cross-sectional shape, and has a shape in which the outer peripheral side is reduced in diameter by, for example, 12 degrees toward the distal end with respect to the axial direction. Both the side and the inner diameter side do not come into contact with the side surface of the annular groove M, and this tip is brought into contact with the bottom surface A1 of the annular groove M of the packing 1 so that the packing 1 is elastically repelled by the pushing force of the plate C. I have.

However, when the load of the pushing force of the plate C exceeds a predetermined value, the flexible portion 5 bends in the inner diameter direction different from the pushing direction of the plate C, and is deformed so as to be rolled up and fall down to the inner diameter side. As shown in FIG. 2 (b), it can be roughly deformed into a "U" shape. During this transformation,
The packing 1 has a flexible portion 5 abutting against the bottom surface A1 of the annular groove M.
Has a sealing property even at the tip.

Further, since the flexible portion 5 has a certain degree of rigidity, the packing 1 is prevented from being deformed arbitrarily by the weight of the packing 1 itself before the plate C comes into contact. In the axial direction can be easily performed. The flexible portion 5 having a certain degree of rigidity prevents deformation of the packing 1 before receiving the load, and prevents a state in which the contact portion between the plate C and the packing 1 is lost and the seal cannot be sealed.

The flexible portion 5 has such a rigidity that it resiliently repels when the load of the pressing force of the plate C is less than a predetermined value, and the direction of the pressing of the plate C when the load of the pressing force of the plate C is more than a predetermined value. Any shape may be used as long as it can be deformed in different directions, and may be bent in any manner. Therefore, the shape of the flexible portion 5 is not particularly limited to the above.

As described in the prior art (see FIG. 5), the packing 1 having the above structure is first attached to the step wall A3 of the case A, and the case 1 is attached to the step wall A4 of the case A to which the packing 1 is attached. By combining B to form a case such as an ignition coil,
As shown in FIG. 2A, the packing 1 is placed in the annular groove M.

Then, the packing 1 is further pushed into the annular groove M up to the positioning position of the plate C, so that sealing can be performed.

When the packing 1 arranged in the annular groove M is pushed by the plate C, the main seal portion 2 of the packing 1
Since the end face of the plate C which comes into contact with the tapered surface 2a is a plane perpendicular to the pushing direction, the tapered surface 2a comes into contact with the plate C from the projected outer diameter side.

For this reason, it is possible to prevent the main seal portion 2 from being deformed and inclined in the outer diameter direction and inclined toward the inner diameter side so that the tapered surface 2a is along the end surface of the plate C, and the packing 1 is always correctly and easily provided. Attached to.

At this time, the annular projecting portion 2b is deformed so as to project toward the inner diameter side of the plate C so that the main seal portion 2 is not deformed and excessive force acts on the inner peripheral side surface B1 of the case 2. Stabilizes the insertability of the packing 1 in the axial direction.

Then, when the packing 1 is pushed into the annular groove M by the plate C, it becomes as shown in FIG.
The deformation of the main seal portion 2 along the end surface of the plate C increases the compression ratio on the outer diameter side, and prevents the packing 1 from tilting toward the inner diameter side. The sealing performance with respect to the inner peripheral side surface can be obtained even when the pushing force of the plate C is lower than the conventional one.

Further, since the plurality of annular projections 4 on the rear side compressed by the amount of pushing of the plate C seal the step wall A3 of the case A, even if the pushing force of the plate C is a low load. In addition, it is possible to seal the step wall A3 which is the side surface of the annular groove M.

The sealing of the step wall A3 of the case A can be performed without using the annular projection 4. However, in the present embodiment, for example, when the amount of pushing in the plate C is small, the sealing of the step wall A3 is changed to the bottom. This can be performed only with the two annular projections 4 on the A1 side, and it is possible to prevent a variation in the sealing performance with respect to the stepped wall surface A3 due to a variation in the pushing amount of the plate C.

The one annular projection 4 is arranged at a position just opposite to the annular seal portion 3, and the opposed annular seal portion 3 and the annular projection 4 are arranged in a case when the packing 1 is arranged in the annular groove M. Does not hinder the assembling, but exhibits sealing properties even when the pushing force of the plate C is low when the packing 1 is compressed.

Here, when the plate C is pushed,
Since the packing 1 is provided with a thickness 6 and the thickness of the flexible portion 5 is reduced, the packing 1 can be easily pushed into the annular groove M even with a small pushing force of the plate C and a low load. it can.

When the load of the pushing force of the plate C exceeds a predetermined value, the flexible portion 5 having the tip abutting on the bottom surface A1 of the annular groove M substantially moves in the outer diameter direction different from the pushing direction of the plate C. ”. By flexing and deforming when the load exceeds a certain level, the plate C
Can further release the applied load.

As a result, the repulsive load of the packing 1 is prevented from becoming too large. Therefore, if the repulsive load of the packing 1 is small, a force for pushing the plate C to a predetermined position is not necessary, and the pushing can be performed with a low load.

Therefore, when the load of the pushing force exceeds a predetermined value, the flexible portion 5 bends, and even if the load of pressing the plate C is low, the packing 1 is pushed into the annular groove M without repelling and the plate C is moved to the predetermined position. Is positioned.

As described above, in this embodiment, since the load pressing the plate C is low, the packing 1 may be damaged, and even if the strength and the insertability of the resin parts supporting the plate C are poor. It does not damage resin parts.

Further, since the packing 1 is flexible as described above, the repulsive load is small, and even if the pushing force of the plate C is set to a low load, the ingress of dust and the like from the seal of the fluid to be sealed in the inside O and the outside P can be prevented. It can be performed.

On the other hand, since the repulsive load of the packing 1 is small, the positioning of the plate C can be performed reliably, and various functions are not affected.

[0068]

According to the present invention, a main seal portion is provided in contact with one wall surface of the annular groove, and the main seal portion projects toward the opening side toward the one wall surface side of the annular groove toward the opening side of the annular groove. Provision of the inclined surface to contact the member prevents the pressing member from first contacting the protruding side of the inclined surface and prevents the packing from falling to the other wall surface side of the annular groove, and securely installs the packing in the annular groove In addition, the compression ratio of the main seal portion is increased on one wall surface side of the annular groove, and the sealing performance with respect to one wall surface of the pressing member and the annular groove is realized even when the pushing force of the pressing member is low. Can be.

An annular seal portion is provided in contact with one wall surface of the annular groove, the thickness between the annular seal portion and the main seal portion is made thin, and buckling preventing means for preventing buckling of the thin portion is provided. Thus, the force required for pushing the pressing member is reduced by reducing the wall thickness, the packing can be pushed with a low load, and the thin portion can be prevented from buckling with a simple force. .

A flexible portion which comes into contact with the bottom surface of the annular groove and flexes in a direction different from the pressing direction of the pressing member when the pressing force of the pressing member becomes a predetermined value or more is provided. Is greater than or equal to a predetermined value, the flexible portion bends, so that the packing does not require an additional pushing load for sealing.

[Brief description of the drawings]

FIG. 1 is a view showing a packing according to an embodiment.

FIG. 2 is a diagram showing a state in which the packing according to the embodiment is mounted in an annular groove.

FIG. 3 is a diagram showing a case and a plate constituting a housing.

FIG. 4 is a view showing a state in which a conventional packing is mounted in an annular groove.

FIG. 5 is a view showing a conventional packing.

FIG. 6 is a view showing a conventional packing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packing 2 Main seal part 2a Tapered surface 3 Annular seal part 4 Annular protrusion 5 Flexible part 6 Stealth 7 Rib A, B case A1 Step (bottom) A2 Step A3, A4 Step wall B1 Inner peripheral side surface C plate M Ring groove N gap

Continued on the front page. (72) Inventor Takashi Nakao 609 Minohara, Nakahara-cho, Nakahara-cho, Miyomoto-gun, Saga Prefecture (72) Inventor Toshiyuki Shinosawa 1053 Otagaya, Tsurugashima-shi, Saitama F-term in Toyo Denso Co., Ltd. (Reference) 3J040 AA02 AA12 AA17 BA03 EA03 EA16 HA08 HA16

Claims (3)

[Claims] 1. An annular groove formed in combination with an annular groove, which is pressed by a pressing member from an opening side of the annular groove,
In the packing which is compressed and sealed in the annular groove, the annular groove is composed of one wall surface, the other wall surface shorter than the axial length of the packing, and a bottom surface connecting the both wall surfaces. A packing comprising a seal portion, wherein an inclined surface which protrudes toward the opening side toward one wall surface side of the annular groove and is in contact with a pressing member is provided on the opening side of the main seal portion. 2. A buckling prevention device comprising: an annular seal portion abutting on one wall surface of an annular groove; a thin wall provided between the annular seal portion and the main seal portion to prevent buckling of the thin portion. 2. The packing according to claim 1, further comprising means. 3. A flexible portion which comes into contact with the bottom surface of the annular groove, and which flexes in a direction different from the pressing direction of the pressing member when the pressing force of the pressing member becomes a predetermined value or more. Or the packing according to 2.