JP2021095983A - Seal structure - Google Patents

Abstract

To provide a seal structure capable of improving productivity by reducing man-hour for machining a groove in which a seal ring is disposed.SOLUTION: A seal structure 100 includes a plurality of seal rings 30a to 30c formed in a C-shape, a notch groove 40 that is formed at an end portion 11 on an outer peripheral side of a first pipe 10 so as to extend from a tip end in an axial direction to a base end side, and to which the plurality of seal rings 30a to 30c are disposed in series and adjacent, a wall portion 50 provided on a second pipe 20, and an energizing member 60 that is provided between a groove wall surface 41 and the wall portion 50 and presses the seal rings 30a to 30c on the groove wall surface 41.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a seal structure.

As the sealing structure, there is a sealing structure for sealing the gap when the end portion of the first pipe is inserted into the end portion of the second pipe.

This seal structure may include a plurality of C-shaped seal rings and a plurality of ring grooves provided at the outer peripheral end of the first pipe and arranging these seal rings one by one. is there.

Japanese Unexamined Patent Publication No. 2015-055280

However, in the above-mentioned seal structure, since it is necessary to form a ring groove for each seal ring, there is a problem that the processing man-hours are large and the manufacturability is poor.

Therefore, the present disclosure was conceived in view of such circumstances, and an object of the present disclosure is to provide a seal structure capable of improving man-hours for processing a groove in which a seal ring is arranged and improving manufacturability.

According to one aspect of the present disclosure, a plurality of C-shaped seal rings are formed in a seal structure for sealing a gap when the end of the first pipe is inserted into the end of the second pipe. A notch groove formed at the outer peripheral end of the first pipe extending from the axial tip to the proximal end, and the plurality of seal rings are arranged in series and adjacent to each other. A notched groove that is opened and a groove wall surface is formed at the base end, a wall portion that is provided on the second pipe and faces the groove wall surface with the plurality of seal rings sandwiched in the axial direction, and the groove wall surface. Provided is a seal structure provided between the wall portion and an urging member for pressing the seal ring against the groove wall surface.

Preferably, the abutments of the plurality of adjacent seal rings are arranged at different positions around their axial centers.

Further, the entire base end surface of the seal ring located closest to the base end side is brought into contact with the groove wall surface.

The urging member is a disc spring, a spring washer, or a corrugated washer.

Further, the first pipe and the second pipe constitute an exhaust passage of an internal combustion engine.

According to the present disclosure, it is possible to reduce the man-hours for processing the groove in which the seal ring is arranged and improve the man-made property.

It is a schematic block diagram of an internal combustion engine using a seal structure. It is an enlarged sectional view of the part II shown in FIG. It is an enlarged sectional view of the part III shown in FIG. It is sectional drawing of the IV-IV line shown in FIG. It is sectional drawing of the VV line shown in FIG. It is sectional drawing of the VI-VI line shown in FIG. It is the schematic sectional drawing which shows the conventional seal structure.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiments.

As shown in FIG. 1, the seal structure 100 of this embodiment is used for the exhaust manifold 2 of the internal combustion engine 1. The white arrows shown in the figure indicate the flow of the exhaust gas G of the internal combustion engine 1. In addition, each direction of up, down, front, back, left, and right shown in the figure is merely defined for convenience of explanation.

The internal combustion engine 1 is a multi-cylinder compression ignition type internal combustion engine mounted on a vehicle, for example, an in-line 4-cylinder diesel engine. The vehicle is a large vehicle such as a truck. However, the type, type, application, etc. of the vehicle and the internal combustion engine are not particularly limited. For example, the vehicle may be a small vehicle such as a passenger car, and the internal combustion engine is a spark-ignition type internal combustion engine such as a gasoline engine. You may.

The exhaust manifold 2 is connected to the engine body 3 (particularly the cylinder head) of the internal combustion engine 1 and collects the exhaust G sent from the exhaust port 1b of each cylinder 1a. The exhaust manifold 2 has a plurality of (four in the illustrated example) exhaust inlets 2a and one exhaust outlet 2b.

Further, the exhaust manifold 2 of the present embodiment is divided into a first pipe 10 located on the rear side and a second pipe 20 located on the front side in advance, and these are connected to each other.

The first pipe 10 and the second pipe 20 are pipe members extending in the front-rear direction, respectively, and form an exhaust passage of the internal combustion engine 1.

Two exhaust inlets 2a are formed on the right side surfaces of the first pipe 10 and the second pipe 20, and are connected to the exhaust port 1b, respectively. On the other hand, one exhaust outlet 2b is formed on the left side surface of the second pipe 20, and is connected to the exhaust pipe 5 on the downstream side via the turbine 4a of the turbocharger 4.

As shown in FIGS. 1 and 2, in the present embodiment, the front end portion 11 of the first pipe 10 is inserted into the rear end portion 21 of the second pipe 20 and is detachably connected. In FIG. 2, the alternate long and short dash line C indicates a common pipe axis C between the end portions 11 and 21.

The exhaust G flowing through the first pipe 10 is sent to the second pipe 20 through these ends 11 and 21, merges with the exhaust G flowing through the second pipe 20, and then sent to the turbine 4a of the turbocharger 4 through the exhaust outlet 2b. Be done.

As shown in FIGS. 2 and 3, the seal structure 100 of the present embodiment seals the gap S when the front end portion 11 of the first pipe 10 is inserted into the rear end portion 21 of the second pipe 20. It has a seal structure. The front-rear direction of the present embodiment coincides with the insertion direction of the front end portion 11 of the first pipe 10 with respect to the rear end portion 21 of the second pipe 20. That is, in the front end portion 11 of the first pipe 10, the distal end side in the axial direction means the front side, and the proximal end side in the axial direction means the rear side. On the other hand, in the rear end portion 21 of the second pipe 20, the distal end side in the axial direction means the rear side, and the proximal end side in the axial direction means the front side.

The seal structure 100 includes three seal rings 30a to 30c and a notch groove 40 formed in the front end portion 11 on the outer peripheral side of the first pipe 10.

The notch groove 40 is formed so as to extend from the front end 11a in the axial direction to the rear side. That is, the notch groove 40 is formed in an L-shaped cross section, the front end is opened, and the groove wall surface 41 is formed at the rear end.

The groove wall surface 41 is arranged rearward from the rear end portion 21 of the second pipe 20 in the axial direction. Further, the front end portion 11 of the first pipe 10 has an outer diameter D1 larger than the inner diameter D2 of the rear end portion 20 of the second pipe 20 at the position of the groove wall surface 41 in the axial direction (D2 <D1). However, the outer diameter D1 of the front end portion 11 of the first pipe 10 may be set to be the same size as or smaller than the inner diameter D2 of the rear end portion 20 of the second pipe 20.

The first to third seal rings 30a to 30c are arranged in series and adjacent to each other in the notch groove 40 in order from the rear.

As shown in FIGS. 4 to 6, the notch groove 40 of the present embodiment is formed in an annular shape extending in the circumferential direction and making one round.

The seal rings 30a to 30c are metal so-called C-shaped rings, and are formed in a C shape. The seal rings 30a to 30c each have a joint portion 31a to 31c at one location around the axis center.

Further, the abutment portions 31a to 31c of the adjacent seal rings 30a to 30c are arranged at different positions around the axial center thereof. The abutment portions 31a to 31c of the present embodiment are arranged at positions deviated from each other by 120 ° around the axis.

As shown in FIGS. 2 and 3, in the present embodiment, the entire rear end surface f1 of the first seal ring 30a located on the rearmost side of the three seal rings 30a to 30c is brought into contact with the groove wall surface 41. .. However, only a part of the rear end surface f1 of the first seal ring 30a (for example, the inner peripheral side portion) may be in contact with the groove wall surface 41.

The bottom surface 42 of the notch groove 40 faces the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20 with the seal rings 30a to 30c sandwiched in the radial direction.

The inner diameter D2 of the rear end portion 21 of the second pipe 20 is set to be larger than the inner diameter D3 of the main body portion 22 of the second pipe 20 located in front of the inner diameter D2 (D2> D3). The main body 22 of the second pipe 20 is arranged so as to be separated forward from the front end 11a of the first pipe 10. The inner diameter D3 of the main body 22 is set to the same size as the inner diameter D4 of the front end 11 of the first pipe 10 (D3 = D4).

Seal rings 30a to 30c are fitted and brought into close contact with the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20.

Specifically, the seal rings 30a to 30c have an outer diameter larger than the inner diameter of the rear end portion 21 in a state where the seal rings 30a to 30c are not fitted to the rear end portion 21 of the second pipe 20. Therefore, the seal rings 30a to 30c tend to expand radially outward by their own elastic force in a state of being fitted to the rear end portion 21 of the second pipe 20.

Further, a space X into which the exhaust gas G flows is formed between the bottom surface 42 of the notch groove 40 and the inner peripheral surface f3 of the seal rings 30a to 30 (see FIG. 3). Therefore, during the operation of the internal combustion engine 1, the seal rings 30a to 30c are urged outward in the radial direction by the pressure of the exhaust gas G flowing into the space X.

That is, the seal rings 30a to 30c are pressed against the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20 by its own elastic force and the pressure of the exhaust G. As a result, the outer peripheral surface f2 of the seal rings 30a to 30c can be brought into close contact with the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20 in the radial direction to be sealed.

Further, the seal structure 100 of the present embodiment is provided on the second pipe 20, and has a wall portion 50 facing the groove wall surface 41 of the notch groove 40 with the seal rings 30a to 30c sandwiched in the axial direction, and the groove wall surface 41. An urging member 60, which is provided between the wall portion 50 and presses the seal rings 30a to 30c against the groove wall surface 41, is provided.

The wall portion 50 is located at the front end of the rear end portion 21 of the second pipe 20 in the axial direction. Further, the wall portion 50 of the present embodiment is formed by the rear end portion of the main body portion 22 of the second pipe 20.

A disc spring is used for the urging member 60. The urging member 60 is made of a metal material and is formed in an annular shape. Further, the urging member 60 is tapered in diameter toward the outside in the radial direction toward the rear.

The urging member 60 of the present embodiment is arranged adjacent to the rear surface of the wall portion 22. Further, the urging member 60 is arranged on the front end surface of the third seal ring 30c via a metal washer 61.

In the present embodiment, first, before inserting the front end portion 11 of the first pipe 10 into the rear end portion 21 of the second pipe 20, the seal rings 30a to 30c are arranged in the notch groove 40 of the first pipe 10. , The urging member 60 and the washer 61 are inserted into the rear end portion 21 of the second pipe 20.

Next, the front end portion 11 of the first pipe 10 is inserted into the rear end portion 21 of the second pipe 20 while reducing the diameter of the seal rings 30a to 30c. As a result, as described above, the seal rings 30a to 30c are pressed against the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20 in an attempt to expand radially outward by its own elastic force.

Next, in this state, the first pipe 10 and the second pipe 20 are bolted and fixed to the engine body 3 (see FIG. 1). As a result, the urging member 60 is pressed forward by the seal rings 30a to 30c via the washer 61, and is elastically deformed by being crushed in the axial direction between the wall portion 50 and the washer 61. As a result, the seal rings 30a to 30c are pressed against the groove wall surface 41 by the urging member 60. As a result, the rear end surface f1 of the first seal ring 30a can be brought into close contact with the groove wall surface 41 in the axial direction to seal the groove wall surface 41.

Further, in the axial direction, the width W1 of the gap S located between the groove wall surface 41 and the rear end portion 21 of the second pipe 20 is set smaller than the width W2 of the first seal ring 30a (W1 <W2). ). As a result, the gap S can be sealed with one first seal ring 30a, so that the sealing performance can be improved.

On the other hand, in the present embodiment, the first pipe 10 and the second pipe 20 are thermally expanded in the front-rear direction by being heated to a high temperature by the exhaust gas G. As a result, the ends 11 and 21 of the first pipe 10 and the second pipe 20 approach each other in the axial direction, and the distance between the groove wall surface 41 and the wall portion 50 is shortened, so that the amount of crushing of the urging member 60 is large. Become. If the urging member 60 is completely crushed and the ends 11 and 21 approach each other in the axial direction, the pipes 10 and 20 may be pressed against each other and deformed. Therefore, the urging member 60 of the present embodiment has a crushing allowance (length in the axial direction) that is not completely crushed even if the first pipe 10 and the second pipe 20 are thermally expanded.

As described above, in the present embodiment, the outer peripheral surfaces f2 of the seal rings 30a to 30c are brought into close contact with the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20 in the radial direction, and the outer peripheral surface f2 is brought into close contact with the groove wall surface 41. 1 The gap S can be sealed by bringing the rear end surface f1 of the seal ring 30a into close contact with the axial direction.

Here, FIG. 7 is an enlarged cross-sectional view showing the conventional seal structure 200. In the following description, the same reference numerals are used for the same or corresponding components as those in the present embodiment, and detailed description thereof will be omitted.

As shown in FIG. 7, in the conventional seal structure 200, three ring grooves 40a to 40c are formed at the front end portion 11 on the outer peripheral side of the first pipe 10 so as to be axially separated from each other, and the seal ring 30a is formed. ~ 30c are arranged one by one in these three ring grooves 40a to 40c. Further, the urging member 50 as in the present embodiment is not provided.

In the conventional seal structure 200, the seal rings 30a to 30c are urged outward in the radial direction by their own elastic force and the pressure of the exhaust G, so that they are attached to the inner peripheral surface 21a of the rear end portion 21 of the second pipe 20. Be pressed. Further, in the conventional seal structure 200, the seal rings 30a to 30c are urged rearward in the axial direction by the pressure of the exhaust G, and are pressed against the groove wall surface 41 on the rear side of the ring grooves 40a to 40c. As a result, the gap S between the front end portion 11 of the first pipe 10 and the rear end portion 21 of the second pipe 20 is sealed at the positions of the ring grooves 40a to 40c, respectively.

However, in the conventional seal structure 200, it is necessary to form ring grooves 40a to 40c for each seal ring 30a to 30c. In particular, since the front ends of these ring grooves 40a to 40c are not open in the axial direction, it is necessary to form not only the rear groove wall surface 41 and the bottom surface 42 but also the front groove wall surface 43, respectively. Therefore, there is a problem that the processing man-hours are large and the manufacturability is poor.

On the other hand, as shown in FIG. 3, only one notch groove 40 of the present embodiment needs to be formed at the front end portion 11 of the first pipe 10, and is formed every 30a to 30c of the seal ring. There is no need to In particular, since the front end of the notch groove 40 of the present embodiment is open, it is not necessary to form the groove wall surface on the front side as in the conventional seal structure 200.

Therefore, with the seal structure 100 of the present embodiment, it is possible to reduce the man-hours for processing the groove in which the seal rings 30a to 30c are arranged and improve the man-made property.

Further, as shown in FIG. 7, since the conventional seal rings 30a to 30c are not arranged adjacent to each other, the exhaust G tends to leak rearward through the respective joints (not shown).

On the other hand, as shown in FIGS. 4 to 6, the seal rings 30a to 30c of the present embodiment are arranged adjacent to each other, and the abutment portions 31a to 31c are located at different positions around the axial center. Therefore, the abutment portions 31a to 31c can be sealed by the adjacent surfaces. As a result, it is possible to prevent the exhaust G from leaking rearward through the abutment portions 31a to 31c.

Further, as shown in FIG. 7, in the conventional seal structure 200, only the inner peripheral side portion of the rear end surface f1 of the seal ring 30a is brought into contact with the groove wall surface 41 on the rear side of each of the ring grooves 40a to 40c. .. Therefore, sealing cannot be performed on the outer peripheral side portions of the seal rings 30a to 30c.

On the other hand, as shown in FIG. 3, in the present embodiment, the entire rear end surface f1 of the first seal ring 30a is brought into contact with the groove wall surface 41, so that the entire rear end surface f1 of the first seal ring 30a is used. Can be sealed sufficiently.

Further, as shown in FIG. 7, in the conventional seal structure 200, when the pressure of the exhaust G is low, the seal rings 30a to 30c cannot be sufficiently urged outward in the radial direction and rearward in the axial direction, so that the sealing performance is sufficient. It may not be possible to secure it.

In particular, since the front ends of the three ring grooves 40a to 40c are not open, components such as soot contained in the exhaust G are difficult to be discharged, and are likely to be deposited on the bottom surface 42. As a result, if the flow of the exhaust G is obstructed, the pressure of the exhaust G may decrease in the space X between the bottom surface 42 of the ring grooves 40a to 40c and the inner peripheral surface f3 of the seal rings 30a to 30. is there. As a result, the seal rings 30a to 30c may be less likely to be urged outward in the radial direction.

On the other hand, as shown in FIG. 3, in the notch groove 40 of the present embodiment, since the front end is open, components such as soot contained in the exhaust G are easily discharged and are deposited on the bottom surface 42. hard. As a result, the flow of the exhaust G is ensured, and the pressure drop of the exhaust G in the space X can be suppressed. As a result, the seal rings 30a to 30c can be sufficiently urged outward in the radial direction by the pressure of the exhaust G, and deterioration of the sealing performance can be suppressed.

Further, in the seal structure 100 of the present embodiment, since the seal rings 30a to 30c are urged rearward in the axial direction by the urging member 60, even if the pressure of the exhaust G decreases, the rear end surface of the first seal ring 30a The sealing performance can be ensured by pressing f1 against the groove wall surface 41.

Further, as shown in FIG. 7, since the front end of the conventional ring grooves 40a to 40c is not open, before inserting the front end portion 11 of the first pipe 10 into the rear end portion 21 of the second pipe 20 It is necessary to expand the diameter of the seal rings 30a to 30c and then arrange them in the ring grooves 40a to 40c. Therefore, there is a problem that the work efficiency is low.

On the other hand, as shown in FIG. 3, in the notch groove 40 of the present embodiment, since the front end is open, the front end portion 11 of the first pipe 10 is replaced with the rear end portion 21 of the second pipe 20. Prior to insertion, the seal rings 30a-30c can be placed in the notch groove 40 without increasing the diameter. Thereby, work efficiency can be improved.

On the other hand, the above-mentioned basic embodiment can be a modification or a combination thereof as follows.

(First modification)
The number of sealings is not limited to three, and may be any number of two or more. Further, the position of the abutment portion may be an arbitrary position around the axis. In the first modification, the two seal rings are arranged in series and adjacent to each other, and the joints of these seal rings are arranged at positions offset by 180 ° around the axis.

(Second modification)
The urging member is not limited to the disc spring, and may be of any type. In the second modification, a spring washer is used as the urging member. Further, as the urging member, a corrugated washer having a cross-sectional shape wavy in the circumferential direction may be used.

(Third modification example)
The first pipe and the second pipe are not limited to the pipes constituting the exhaust manifold. In the third modification, two exhaust pipes arranged in series at a position downstream of the turbocharger are used.

Although the embodiments of the present disclosure have been described in detail above, the embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications and applications included in the idea of the present disclosure defined by the claims. Examples, equivalents are included in this disclosure. Therefore, this disclosure should not be construed in a limited way and may be applied to any other technique that falls within the scope of the ideas of this disclosure.

10 First pipe 11 Front end (end of first pipe)
20 2nd pipe 21 Rear end (end of 2nd pipe)
30a 1st seal ring (seal ring)
30b 2nd seal ring (seal ring)
30c 3rd seal ring (seal ring)
40 Notch groove 41 Groove wall surface 50 Wall part 60 Biasing member 100 Seal structure S Gap G Exhaust

Claims (5)

In the sealing structure for sealing the gap when the end of the first pipe is inserted into the end of the second pipe,
Multiple seal rings formed in a C shape and
A notch groove formed at the outer peripheral end of the first pipe extending from the axial tip to the proximal end, and the plurality of seal rings are arranged in series and adjacent to each other, and the tip is opened. , A notched groove with a groove wall surface formed at the base end,
A wall portion provided on the second pipe and facing the groove wall surface with the plurality of seal rings sandwiched in the axial direction,
A seal structure provided between the groove wall surface and the wall portion, and provided with an urging member for pressing the seal ring against the groove wall surface. The seal structure according to claim 1, wherein the abutments of the plurality of adjacent seal rings are arranged at different positions around the axis thereof. The seal structure according to claim 1 or 2, wherein the entire base end surface of the seal ring located closest to the base end side is brought into contact with the groove wall surface. The seal structure according to any one of claims 1 to 3, wherein the urging member is a disc spring, a spring washer, or a corrugated washer. The seal structure according to any one of claims 1 to 4, wherein the first pipe and the second pipe constitute an exhaust passage of an internal combustion engine.

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