JP7246905B2 - sealing device - Google Patents

Description

The present invention relates to sealing devices.

2. Description of the Related Art In the fields of automobiles and general-purpose machines, sealing devices are used to seal members passing through openings provided in housings.

For example, Patent Literature 1 describes an oil seal provided in an opening of a rocker cover for inserting a pipe for mounting a spark plug. Patent Documents 2 and 3 describe oil seals for sealing engine crankshafts.

Patent Document 1 discloses a configuration example in which a baffle plate is welded to the lower surface of a rocker cover and an oil seal is arranged between the rocker cover and the baffle plate (paragraphs [0008] to [0010] of Document 1, See Figure 1). An oil seal support is welded to the outer periphery of the oil seal, and the oil support is fitted and supported between the rocker cover and the baffle plate. An oil support is welded to the baffle plate.

Patent Document 2 discloses a configuration example in which an oil seal is provided in a crankshaft opening (crankshaft hole 12) provided in an engine cover to seal the crankshaft passing through the opening (paragraph [ 0009] to [0015]).

Patent Document 3 discloses a configuration example in which an oil seal is provided in an opening (through hole 22) provided in a timing chain cover to seal a crankshaft passing through the opening (paragraphs [0029] and [0033] of Document 3). ~ see [0036]).

The rocker cover of Patent Document 1, the engine cover of Patent Document 2, and the timing chain cover of Patent Document 3 all form part of the housing. The above-mentioned "member passing through the opening" is a pipe for attaching a spark plug in Patent Document 1, and a crankshaft in Patent Documents 2 and 3.

JP-A-06-034153 JP-A-07-055015 Japanese Unexamined Patent Application Publication No. 2015-121300

In the field of automobiles, weight reduction has always been an issue. In particular, in recent years, against the background of global energy problems, the demand for energy saving has increased, and weight reduction has become even more important. A common way to reduce weight is to review materials.

For example, in the configuration example of Patent Document 1, synthetic resin is used as the material of the rocker cover, the oil seal support, and the baffle plate (see paragraph [0008] of Document 1). In the configuration example of Patent Document 2, the engine cover is manufactured from molded plastic (see paragraph [0009] of Document 2). In the configuration example of Patent Document 3, the timing chain cover is made of polyamide, which is a resin material (see paragraph [0029] of Document 3). Thus, in the configuration examples shown in Patent Documents 1 to 3, resin parts are used for part of the housing and the sealing device to reduce the weight.

When a housing made of resin is used, deformation due to heat becomes a problem. This is because a housing made of resin undergoes a greater dimensional change due to thermal expansion and a larger creep deformation than a housing made of metal. A similar problem occurs when a resin part is used for the sealing device. For this reason, when the housing or the sealing device is deformed by heat, the tight contact between the opening and the sealing device is reduced, causing the leakage of the sealing fluid or, in some cases, the disengagement of the sealing device. .
Improvement is desired.

It is possible to solve the problem of the sealing device falling off by means of a retaining structure. Patent Documents 1 to 3 also employ a retaining structure for a sealing device. However, the retainer structure increases the number of parts, resulting in a complicated structure. As a result, new problems such as an increase in part cost, manufacturing cost, and an increase in assembly man-hours are caused.
Improvement is desired.

SUMMARY OF THE INVENTION An object of the present invention is to prevent leakage of a sealing fluid and disconnection of a sealing device by a simple structure even if a resin component is deformed by heat.

One aspect of the sealing device includes a cylindrical resin ring that is mounted in an opening provided in a housing, and whose back end face abuts against a receiving surface provided in a stepped shape at the back of the opening; a rubber seal lip fixed to the resin ring and in close contact with the surface of the member arranged in the opening; a screw fastening portion provided on the outer peripheral surface of the resin ring and screwed to the inner peripheral surface of the opening; a seal provided annularly on the inner end surface of the resin ring and in close contact with the receiving surface of the housing, wherein the seal is a ring fitted into an annular groove formed concavely on the inner end surface of the resin ring; The resin ring is a sealing member having a shape that does not fit in the annular groove and keeps the rear end face of the resin ring in a non-contact state with the receiving surface of the housing.

Even if the resin component is deformed by heat, it is possible to prevent the seal fluid from leaking and the sealing device from coming off with a simple structure.

FIG. 2 is a horizontal cross-sectional view showing only half of the sealing device held by the housing as one embodiment, cut along the axis of the crankshaft; Fig. 4 is a horizontal sectional view showing only half of the sealing device cut along the axis of the crankshaft; The perspective view which shows the resin ring with which the seal|sticker was inserted. FIG. 10 is a horizontal cross-sectional view showing only half of the sealing device cut along the axis of the crankshaft as another embodiment; FIG. 10 is a horizontal cross-sectional view showing only half of the sealing device cut along the axis of the crankshaft as another embodiment; FIG. 10 is a horizontal cross-sectional view showing only half of the sealing device cut along the axis of the crankshaft as another embodiment;

An embodiment will be described with reference to FIGS. 1 to 3. FIG. This embodiment shows an example of a sealing device that is provided in a crankcase of an engine that constitutes a part of a housing and that seals the crankshaft.

As shown in FIG. 1, the crankcase 11 is provided with an opening 12 through which a crankshaft 31 indicated by a dashed line extends. A sealing device 101 is attached to the opening 12 . A sealing device 101 seals the crankshaft 31 . In FIG. 1, A is the outside of the plane, and B is the inside of the plane.

The crankcase 11 is made of resin. The inner peripheral surface of the opening 12 is formed in a stepped shape and has a large diameter portion 12a and a small diameter portion 12b. The stepped shape is a shape in which the large-diameter portion 12 a and the small-diameter portion 12 b are connected in a plane along a direction perpendicular to the axial direction of the opening 12 . When the opening 12 is viewed from the outside A side of the machine, this surface is a stepped surface provided at the back of the opening 12 appearing between the large-diameter portion 12a and the small-diameter portion 12b. In this embodiment, this surface is called a receiving surface 13 .

The axis of opening 12 coincides with the axis of crankshaft 31 and sealing device 101 passing through opening 12 . This axis is indicated by C in FIG.

On the inner peripheral surface of the opening 12, the large-diameter portion 12a occupies a region longer in the axial direction than the small-diameter portion 12b. A female thread 14 is formed on the inner peripheral surface of the large diameter portion 12a.

As shown in FIG. 2, the sealing device 101 is formed by bridging and bonding a rubber-like elastic body 131 to the inner peripheral surface of a resin ring 111 . The rubber-like elastic body 131 integrally forms the seal lip 132 and the dust lip 141 .

As shown in FIGS. 1 to 3, the resin ring 111 is a resin-made annular member having a cylindrical shape. The resin ring 111 has a male thread 112 as a threaded joint formed on its outer peripheral surface. The male thread 112 is screwed to the female thread 14 provided in the opening 12 of the crankcase 11 . The male thread 112 is molded integrally with the resin ring 111 .

As the male screw 112 is screwed into the female screw 14 in the opening 12 , the resin ring 111 advances toward the inside of the opening 12 , and the end surface 113 on the inside abuts against the receiving surface 13 . A recessed annular groove 114 is provided concentrically with the resin ring 111 in the end face 113 on the far side. An O-ring 115 is fitted in this annular groove 114 as a seal. Annular groove 114 is formed to a depth that allows O-ring 115 to protrude from end face 113 .

The resin ring 111 has a stepped inner peripheral surface and has a large diameter portion 116a and a small diameter portion 116b. The large-diameter portion 116a is an inner peripheral surface on the side closer to the end surface 113 on the far side. The small diameter portion 116b is the inner peripheral surface on the side closer to the end surface 117 on the front side. The stepped shape of the inner peripheral surface of the resin ring 111 is a shape in which the large-diameter portion 116a and the small-diameter portion 116b are connected with each other along the direction orthogonal to the direction of the axis C of the sealing device 101. As shown in FIG. In this embodiment, this surface is called a step surface 118 .

The rubber-like elastic body 131 is adhered to the inner peripheral surface of the resin ring 111 across the small diameter portion 116 b and the step surface 118 . The portion bonded to the small-diameter portion 116 b is relatively thick and is continuous with the seal lip 132 and the dust lip 141 . The rubber-like elastic body 131 adhered to the step surface 118 is in the form of a film.

The seal lip 132 is an annular member provided closer to the machine interior B than the dust lip 141 . The seal lip 132 has a triangular cross-sectional shape with a lip end 135 at the top where an inner slope 133 that is a slope on the machine B side and an outer slope 134 that is a slope on the outside A side intersects. The lip end 135 is in close contact with the crankshaft 31 to separate the space on the side of the machine B and the space on the side of the machine outside A, thereby sealing the two spaces.

The rubber-like elastic body 131 has a mounting groove 136 with a semicircular cross-section at a position that contacts the back side of the lip end 135 of the seal lip 132 . A garter spring 137 formed by annularly connecting both ends of a coil spring is fitted in the mounting groove 136 . The garter spring 137 increases the close contact force of the lip end 135 of the seal lip 132 to the crankshaft 31 by its tightening force.

The dust lip 141 is an annular member provided on the outside A side of the seal lip 132 and obliquely extending the lip end 142 toward the outside A side. A lip end 142 of the dust lip 141 extending to the outside A side is in close contact with the crankshaft 31 . The dust lip 141 prevents foreign matter such as sludge and dust from entering from the outside A side to the inside B side of the machine.

The resin ring 111 has a front end face 117 provided with a mounting portion 119 fitted with a jig (not shown) for rotating the resin ring 111 . The mounting portion 119 is in the shape of a plurality of depressions arranged along the circumference of the end surface 117 on the front side. The jig can fit claws (not shown) into these mounting portions 119 to rotate the resin ring 111 .

The action will be explained.

In order to attach the sealing device 101 to the crankcase 11 , the sealing device 101 with the crankshaft 31 penetrating therethrough is fitted into the opening 12 . Since the female thread 14 is formed in the opening 12 , the male thread 112 of the resin ring 111 is screwed into the female thread 14 .
This work is performed by fitting the claws of a jig (not shown) into the mounting portion 119 provided on the front end face 117 of the resin ring 111 and rotating the sealing device 101 with the jig. The sealing device 101 is screwed into the opening 12 , and the O-ring 115 provided on the end face 113 on the far side is abutted against the receiving surface 13 in the opening 12 . By further screwing in from this state, the sealing device 101 is completely tightened and attached to the crankcase 11 .

When the sealing device 101 is attached to the crankcase 11 , the O-ring 115 is in close contact with the receiving surface 13 to produce a sealing effect, so that the end surface 113 on the far side does not contact the receiving surface 13 even if it is in contact with the receiving surface 13 . Either state is acceptable. The end face 113 on the far side comes into contact with the receiving surface 13 when the O-ring 115 deformed by being crushed fits within the annular groove 114 , and when it cannot fit within the annular groove 114 . becomes non-contact with

A sealing device 101 attached to the crankcase 11 brings the lip end 135 of the seal lip 132 into close contact with the crankshaft 31 to prevent oil from leaking from the inside B to the outside A of the machine. The dust lip 141 prevents foreign matter such as sludge and dust from entering from the outside A side to the inside B side of the machine.

The sealing device 101 abuts the inner end surface 113 of the resin ring 111 against the receiving surface 13 in the opening 12 in a contact state or in a non-contact state via the O-ring 115 to bring the O-ring 115 into close contact with the receiving surface 13. Sealed. This also prevents oil from leaking from the gap between the opening 12 and the resin ring 111 .

Compared to metals, resins have large dimensional changes due to thermal expansion and large creep deformation. When the engine warms up and the heat is transferred to the crankcase 11, the crankcase 11 deforms. At this time, in the sealing device 101 of the present embodiment, since the opening 12 of the crankcase 11 and the resin ring 111 of the sealing device 101 are screwed together by the female thread 14 and the male thread 112, the inner diameter of the opening 12 is enlarged. However, the sealing device 101 does not come off from the opening 12.例文帳に追加

Moreover, since the resin ring 111 of the sealing device 101 is also made of resin, the heat conducted to the crankcase 11 is also conducted to the resin ring 111, and the resin ring 111 tends to expand its outer diameter. As a result, the screw connection between the opening 12 and the resin ring 111 is less likely to loosen, and the oil leakage prevention effect of the O-ring 115 can be maintained.

Therefore, according to the present embodiment, even if the crankcase 11 and the resin ring 111 of the sealing device 101, which are resin parts, are deformed by heat, the simple structure prevents oil leakage and the sealing device 101 from coming off. can be

In addition, according to this embodiment, the following effects are also obtained.

Since the opening 12 of the crankcase 11 and the resin ring 111 of the sealing device 101 are screwed together by the female thread 14 and the male thread 112 , the sealing device 101 can be easily attached to and detached from the crankcase 11 . Moreover, since the opening 12 is not damaged by attaching and detaching the sealing device 101, the crankcase 11 and the resin ring 111 can be reused.

A male screw 112 forming a screw fastening portion is integrally formed with the resin ring 111 . Therefore, an increase in the number of parts due to the provision of the male screw 112 can be suppressed, and the work of assembling the male screw 112 into the resin ring 111 is also unnecessary, so that labor can be saved.

Since the seal between the opening 12 and the resin ring 111 is realized by a simple structure in which the O-ring 115 is fitted into the annular groove 114 provided in the end face 113 on the far side of the resin ring 111, the parts cost can be reduced. The structure can be simplified.

An end surface 117 on the front side of the resin ring 111 is provided with a mounting portion 119 that is fitted with a jig for rotating the resin ring 111 . A sealing device 101 can be easily screwed onto 12 . Since the sealing device 101 can be mounted without protruding from the crankcase 11, it is possible to prevent the vicinity of the entrance of the opening 12 from increasing in size due to the provision of the sealing device 101.

Another embodiment will be described based on FIG.
This embodiment is an example in which a square seal 201 is provided as a seal between the opening 12 and the resin ring 111 instead of the O-ring 115 . The corner seal 201 is also common to the O-ring 115 in that it is a ring-shaped sealing material. The difference from the O-ring 115 is that it is possible to further strengthen the close contact force to the receiving surface 13 inside the opening 12 . Adoption of the corner seal 201 works advantageously when it is necessary to increase the close contact force to the receiving surface 13 .

In the example shown in FIG. 4, the corner seal 201 is tightly accommodated within the annular groove 114 . Therefore, when the sealing device 101 is attached to the crankcase 11 , the crushed and deformed corner seal 201 cannot be completely accommodated in the annular groove 114 , and the rear end surface 113 is out of contact with the receiving surface 13 .

Yet another embodiment will be described with reference to FIG.
This embodiment is an example in which a gasket 211 is provided as a seal between the opening 12 and the resin ring 111 instead of the O-ring 115 and the corner seal 201 . The gasket 211 is also common to the O-ring 115 and the corner seal 201 in that it is a ring-shaped sealing material. The difference from the O-ring 115 and the corner seal 201 is that the degree of freedom in shape is high.

For example, a gasket 211 shown in FIG. 5 has a shape in which lip ends 212 are arranged in two rows on the inner peripheral side and the outer peripheral side in the circumferential direction. The gasket 211 can increase the close contact area with the receiving surface 13 in the opening 12 by the lip edge 212 of each row to improve the sealing performance.

In the example shown in FIG. 5, the gasket 211 is tightly accommodated within the annular groove 114 . Therefore, when the sealing device 101 is attached to the crankcase 11 , the crushed and deformed gasket 211 cannot be completely accommodated in the annular groove 114 , and the rear end surface 113 is in a non-contact state with the receiving surface 13 .

Yet another embodiment will be described with reference to FIG.
The seal of this embodiment is a rubber sheet 221 fixed in layers to the end surface 113 on the back side of the resin ring 111 . The O-ring 115, the corner seal 201, and the gasket 211 are all ring-shaped sealing materials, whereas this embodiment is different in that they are sheet-shaped sealing materials. The sheet 221 is formed integrally with the rubber-like elastic body 131 forming the seal lip 132 and the dust lip 141, and wraps around the rear end surface 113 via the large-diameter portion 116a. The sheet 221 is provided on the entire surface or part of the end surface 113 .

The sealing device 101 attached to the opening 12 abuts the end face 113 on the inner side of the resin ring 111 against the receiving surface 13 in the opening 12 via the sheet 221 to bring the sheet 221 into close contact with the receiving surface 13 for sealing. . As a result, oil leakage from the gap between the opening 12 and the resin ring 111 can be prevented.

According to this embodiment, the receiving surface 13 in the opening 12 is sealed over a wide area by the sheet 221 provided on the entire surface or part of the end surface 113 on the far side. This can enhance the sealing action between the opening 12 and the sealing device 101 .

According to this embodiment, the sheet 221 can be integrally formed with the rubber-like elastic body 131 when the rubber-like elastic body 131 is adhered to the resin ring 111, so that manufacturing and assembly can be facilitated.

Four embodiments have been introduced above. Various modifications and changes are possible in carrying out these embodiments.

11 crankcase (housing)
REFERENCE SIGNS LIST 12 opening 12a large diameter portion 12b small diameter portion 13 receiving surface 14 internal thread 31 crankshaft (member arranged in the opening)
101 sealing device 111 resin ring 112 male screw (screw fastening portion)
113 Back end face 114 Annular groove 115 O-ring (seal, ring-shaped sealing material)
116a Large-diameter portion 116b Small-diameter portion 117 Front end surface 118 Step surface 119 Mounting portion 131 Rubber-like elastic body 132 Seal lip 133 Inner slope 134 Outer slope 135 Lip end 136 Mounting groove 137 Garter spring 141 Dust lip 142 Lip end 201 Corner seal 211 Gasket A Outside B Inside

Claims (6)

a cylindrical resin ring that is mounted in an opening provided in a housing and has a back end surface that abuts against a receiving surface provided in a stepped shape at the back of the opening;
a rubber seal lip fixed to the resin ring and brought into close contact with the surface of the member arranged in the opening;
a screw fastening portion provided on the outer peripheral surface of the resin ring and screwed to the inner peripheral surface of the opening;
a seal provided annularly on the end surface of the resin ring on the back side and in close contact with the receiving surface of the housing;
with
The seal is
A ring-shaped seal member that fits into an annular groove recessed in the end face of the resin ring on the back side,
The resin ring cannot be completely accommodated in the annular groove, and the end face on the back side of the resin ring is brought into a non-contact state with the receiving surface of the housing.
sealing device. The screw fastening portion is integrally molded with the resin ring,
A sealing device according to claim 1 . the seal is an O-ring ;
A sealing device according to claim 1 . The seal is a square seal having a rectangular cross-section in a direction orthogonal to the circumferential direction ,
A sealing device according to claim 1 . The seal has a cross-sectional shape in a direction orthogonal to the circumferential direction, and has a shape in which lip ends abutting against the receiving surface of the housing are arranged in two rows on the inner peripheral side and the outer peripheral side of the resin ring in the circumferential direction. is
A sealing device according to claim 1 . The front end face of the resin ring is provided with a mounting portion that fits with a jig that rotates the resin ring.
A sealing device according to claim 1 .

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