JP2014098412A - Pipe connection flange - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a pipe connection flange capable of connecting pipes while keeping high airtightness and water-tightness to be manufactured in good productivity and less-expensive manner.SOLUTION: This invention relates to a pipe connection flange 10 for use in connecting pipes in air-tightness or water-tightness condition. A plurality of scratch-like pressed grooves 15 extending in parallel to each other along the inner periphery 11a of a port hole 11 into which a pipe 1 is fitted are formed in an area of contacting with a gasket in a seal surface 13 that is connected to a mating side seal surface while the gasket being held. An area in the seal surface 13 contacted with the gasket is an annular area between an imaginary line B and the inner periphery 11a of the port hole 11 and many fine shallow grooves are formed there by a press working.

Description

  The present invention relates to a pipe connection flange for connecting a pipe (tube body) in an airtight or watertight manner in various pipes such as an internal combustion engine (engine) such as an automobile, a pump, water supply / drainage, air conditioning and high pressure air.

  When performing various types of piping as described above, generally, pipe connection flanges (hereinafter also simply referred to as “flanges”) are fixed to the ends of the pipes on the connected side and the connected side, and the flanges are connected to gaskets ( It is also connected by tightening with a pinch (also called packing).

  For example, as shown in FIG. 10, the end of the pipe 101 on the connected side and the end of the pipe 102 on the connecting side are fitted into the port holes 201a and 202a of the flanges 201 and 202, respectively. The flanges 201 and 202 are fixed to each other. The fixing is usually performed by welding over the entire circumference (in FIG. 10, the cross section of the welded portion is indicated by a small black triangle).

  Then, a flat ring-shaped gasket 300 is sandwiched between the opposing seal surfaces 201 b and 202 b of the flanges 201 and 202, and the flanges 201 and 202 are tightened evenly by a plurality of bolts 400 and nuts 500. . Thereby, the pipe 201 and the pipe 202 can be connected in an airtight or watertight manner. The seal surfaces 201b and 202b are also referred to as gasket seats.

A pipe connection flange is a kind of pipe joint. In addition to the connection between pipes as described above, a pipe is connected to an intake port or a discharge port of a device that sucks or discharges fluid such as an engine cylinder head, a pump or a tank. Also used when connecting directly.
Although the material of a flange changes with uses, for example, carbon steel, alloy steel, stainless steel, copper alloy, aluminum alloy etc. are used.
The gasket includes a soft gasket formed of rubber or the like and a metal gasket formed by punching a metal plate such as copper, stainless steel, or aluminum. Further, as a sealing material similar to the gasket, a seal ring such as an O-ring shape or a hollow ring shape is also used.

A metal gasket is used for a connection part that becomes hot, such as a connection part of an exhaust pipe in an automobile engine.
Such a connection using a flange and a gasket has advantages such as high airtightness and watertightness, strength, good workability, and easy disassembly and assembly as compared with screwed connection.

However, for example, a flange currently used for an exhaust pipe connection portion in an engine increases the air tightness by increasing the smoothness of the seal surface (gasket seat), particularly in the region in contact with the gasket as much as possible. Yes.
Therefore, scratches are not allowed on the sealing surface of the flange, and surface accuracy close to a mirror surface is required. That is, the surface accuracy and flatness of the seal surface in the flange are considered to be important factors for improving the airtightness. The same applies to flanges for other applications.
Therefore, current flange products are manufactured at a high cost by performing cutting and polishing in order to obtain surface accuracy and flatness of the seal surface. Therefore, there is a problem that productivity is low and cost is high.

  The present invention has been made in order to solve such a problem in the conventional pipe connecting flange, and a pipe connecting flange capable of connecting a pipe with high airtightness and watertightness can be produced with high productivity and at low cost. The purpose is to enable manufacture.

In order to achieve the above object, in the flange for pipe connection for connecting a pipe in an airtight or watertight manner, the present invention provides an area in contact with the gasket on the seal surface joined with the seal surface on the other side sandwiching the gasket. A plurality of scratch-like press grooves extending in the direction along the inner periphery of the port hole into which the pipe is inserted and parallel to each other are formed.
The “scratch-like press groove” in the present invention refers to a thin and shallow groove in the form of scratches (scratches and scratches) formed by pressing.

When the port hole is a circular port hole into which a cylindrical pipe is inserted, the scratch-like press groove may be formed evenly in a region in contact with the gasket.
In addition, when the port hole is a rectangular port hole into which a rectangular tube-like pipe is inserted and each corner portion has a radius, the scratch-like press groove is formed in a region corresponding to the corner portion. It is better to form more than the region corresponding to the straight line portion.

At least portions on both sides of each scratch-like press groove in the region where the scratch-like press groove is formed on the seal surface may be formed as a protrusion protruding from the other region of the seal surface.
In addition, in a pipe connection flange that uses a seal ring instead of the gasket, a concave groove into which the seal ring is fitted is fitted into the seal surface that is bonded to the mating seal surface with the seal ring interposed therebetween. It is preferable that a plurality of scratch-like press grooves are provided along the inner periphery of the port hole to be formed and extend in the direction along the inner periphery of the port hole and parallel to each other on the bottom surface of the concave groove.

  Alternatively, a taper surface having a downward slope toward the port hole is formed between the seal surface and the port hole into which the pipe is inserted, and the taper surface is formed between the mating seal surface and the mating side or the self side. A tapered surface for pressing the seal ring between the outer peripheral surface of the pipe and a plurality of scratch-like press grooves extending in the direction along the inner periphery of the port hole and parallel to each other may be formed on the tapered surface.

  In the flange for pipe connection according to the present invention, a plurality of scratch-like press grooves extending in the direction along the inner periphery of the port hole and parallel to each other are formed in a region in contact with the gasket or seal ring on the seal surface. The frictional force with the gasket or the seal ring can be increased to improve the airtightness and watertightness.

Therefore, it is not necessary to increase the surface accuracy and flatness of the seal surface so much, and it can be easily manufactured only by pressing, so that productivity is greatly improved and can be provided at low cost.
In addition, the area that contributes to sealing becomes clear by contact with the gasket or seal ring on the sealing surface, and the flatness and scratches in the area that does not contribute to sealing do not become a problem in product performance. Yield is improved and further cost reduction is possible.

It is the top view of 1st Example of the flange for pipe connection by this invention, and sectional drawing in alignment with the YY line. FIG. 2 is an enlarged view of a portion surrounded by a circle A of an imaginary line in FIG. It is a top view of 2nd Example of the flange for pipe connection by this invention. FIG. 4 is an enlarged view of a portion surrounded by a phantom line circle C in FIG. 3. It is sectional drawing which shows the principal part of 3rd Example of the flange for pipe connection by this invention with a part of flange for pipe connection and the seal ring of the other party.

It is sectional drawing which shows the principal part of 4th Example of the flange for pipe connection by this invention with a part of gasket which has a spring property. It is an expanded sectional view which shows the principal part of 5th Example of the flange for pipe connection by this invention with a BGT gasket. It is an expanded sectional view which shows the principal part of the modification of the flange for pipe connection. It is sectional drawing in alignment with the axial direction of the pipe of the part which connected the pipes using the 6th Example of the flange for pipe connection by this invention. It is sectional drawing which follows the axial direction of the pipe of the part which connected the pipes using the conventional flange for pipe connection.

  Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings. In the description of each embodiment, the pipe connecting flange is simply referred to as “flange”.

[First embodiment]
First, a first embodiment of a pipe connecting flange according to the present invention will be described with reference to FIGS. 1A is a plan view of the flange, FIG. 1B is a cross-sectional view taken along the line Y-Y in FIG. 1A, and FIG. 2 is an imaginary line circled in FIG. It is an enlarged view.
As shown in FIG. 1 (a), the flange 10 has a shape obtained by rounding each apex 10a whose planar shape is an equilateral triangle, and a circular pipe into which a cylindrical pipe to be connected is fitted at the center. The port hole (opening) 11 is formed large. Moreover, the bolt hole 12 is formed in three places near each top part 10a, respectively.

The flange 10 is a thick plate-shaped flange as shown in FIG. 1B, and one side (the left side) of the flange 10 is a seal surface (gasket seat) joined with a mating seal surface and a gasket interposed therebetween. ) 13. And as shown with a virtual line, the edge part of the pipe 1 which should be connected can be inserted in the port hole 11, and this flange 10 can be fixed to the outer peripheral surface by welding.
In order to make the connection with the pipe more reliable, a hub protruding with the same inner diameter as the port hole 11 may be formed on the surface opposite to the seal surface 13. A flange provided with such a hub is referred to as a hub flange, and a flange not provided with a hub is referred to as a plate flange.

  When the annular area between the inner periphery 11a of the port hole 11 and the imaginary line B shown in FIG. 1A on the sealing surface 13 of the flange 10 is connected to the flange of the other pipe or device or the like. The region 13a (see FIG. 2) is in contact with a gasket (not shown). In this region 13a, a plurality of scratch-like press grooves 15 extending in the direction along the inner periphery 11a of the port hole 11 and parallel to each other are formed.

  The scratch-shaped press grooves 15 are scratches (scratches and scratches) formed by press working, and are not necessarily formed in the entire region 13a, but as many as possible are formed. Is good. The number of scratch-like press grooves 15 varies depending on the width of the region 13a in contact with the gasket, but may be 5 to 10, for example, or more.

In this embodiment, a large number of lines are formed at equal pitches (intervals) concentrically with the inner periphery 11 a of the circular port hole 11. That is, the scratch-like press groove 15 is formed uniformly over the entire circumference of the region 13a that contacts the gasket on the seal surface 13.
The two flanges 10 are used, and the flanges 10 are fixed to the respective ends of the two pipes to be connected, as in the conventional example shown in FIG. The two pipes can be connected in an air-tight or water-tight manner by sandwiching a gasket between the opposed seal surfaces 13 and attaching and tightening nuts to bolts inserted through the respective bolt holes 12.

  And the frictional force between gaskets becomes large by the scratch-like press groove | channel 15 formed in the area | region 13a which contacts the gasket in each sealing surface 13. FIG. In addition, slight annular irregularities are formed on the contact surface of the gasket along the scratch-shaped press groove 15, and there is an effect of blocking the fluid path between the port hole 11 and the outside in multiple layers. Thereby, airtightness and watertightness can be sufficiently enhanced.

Therefore, the flange 10 does not need to increase the surface accuracy and flatness of the seal surface 13 so much and can be easily manufactured only by pressing, so that the productivity can be greatly improved and provided at a low cost.
In addition, since many scratch-like press grooves 15 are formed in the region 13a that contributes to sealing by contacting with the gasket of the sealing surface 13, the region 13a becomes clear. Therefore, since the flatness and scratches in the region that does not contribute to sealing do not become a problem in product performance, the yield is improved together with the improvement of productivity, and the cost can be further reduced.

[Second Embodiment]
Next, a second embodiment of the pipe connecting flange according to the present invention will be described with reference to FIGS. 3 is a plan view of the flange, and FIG. 4 is an enlarged view of a portion surrounded by a phantom line circle C in FIG.

  As shown in FIG. 3, the flange 20 of the second embodiment has a rectangular shape with a rounded shape at each corner 20a, and a rectangular tube having a substantially rectangular cross section at the center. The rectangular port hole 21 into which the is inserted is formed large. Each corner portion 21c on the inner periphery 21a of the port hole 21 has a radius. In addition, bolt holes 22 are formed at four locations close to each planar corner 20a. The flange 20 may also be a plate flange or a hub flange.

And the strip-shaped area | region along the inner periphery 21a between the inner periphery 21a of the port hole 21 shown in FIG. 3 and the virtual line D in the sealing surface 23 of this flange 20 is a flange of a partner pipe or equipment, etc. The region 23a is in contact with a gasket (not shown) when connecting. A plurality of scratch-like press grooves 25 extending in the direction along the inner periphery 21a of the port hole 21 and parallel to each other are formed in the region 23a.
In addition, when connecting a square tube-shaped pipe having a substantially square cross section, a port hole into which the pipe is inserted may be formed in a square shape so that each corner portion on the inner periphery has a rounded shape.

In this embodiment, in the region 23a in contact with the gasket, as clearly shown in FIG. 4, the region a1 corresponding to each corner portion 21c of the inner periphery 21a of the port hole 21 is more than the region a2 corresponding to the straight portion. Many scratch-like press grooves 25 are formed.
3 and 4, for the sake of illustration, the pitch (interval) of the scratch-like press grooves 25 appears slightly rougher in the region a1 corresponding to each corner portion 21c than in the region a2 corresponding to the straight portion. However, in practice, it is better to increase the number of the scratch-like press grooves 25 by forming the regions a1 corresponding to the respective corner portions 21c so that the pitches are denser or at least equal.

  Even when the rectangular pipe is connected using the flange 20 of the second embodiment, substantially the same effect as that obtained when the cylindrical pipe is connected by the flange 10 of the first embodiment described above can be obtained. . However, generally, when the port hole of the flange is rectangular, the air tightness and water tightness at each corner portion on the inner periphery tend to be slightly lowered.

  Therefore, in this embodiment, in the region a1 corresponding to each corner portion 21c of the inner periphery 21a of the port hole 21, more scratch-like press grooves 25 are formed than in the region a2 corresponding to the straight portion, and the corner portion is formed. The airtightness and watertightness of the tank are further enhanced. Thereby, uniform high airtightness and watertightness can be obtained over the entire circumference.

[Third embodiment]
Next, a third embodiment of the flange for pipe connection according to the present invention will be described with reference to FIG. FIG. 5 is a sectional view showing the main part of the flange together with a part of the mating flange and the seal ring.

  In the flange 30 of the third embodiment, a concave groove 34 into which the seal ring 3 is fitted is inserted into a seal surface 33 that is joined with the seal surface 43 of the counterpart flange 40 and the seal ring 3 interposed therebetween. It is provided along the inner periphery 31 a of the hole 31. A plurality of scratch-like press grooves 35 extending in the direction along the inner periphery 31 a of the port hole 31 and parallel to each other are formed on the bottom surface of the concave groove 34.

The width w and depth d of the concave groove 34 correspond to the cross-sectional diameter of the seal ring 3. For example, when the cross-sectional diameter of the seal ring 3 is 3.5 mm, the width w is 5.0 mm and the depth d is 2. It should be about 8 mm.
Although the scratch-like press groove 35 is shown in FIG. 5 as being slightly larger for the sake of illustration, the scratch-like press groove 35 is actually a thin and shallow groove similar to the above-described embodiments, and at least 5 to 10 grooves on the bottom surface of the concave groove 34. Is formed. The scratch-like press groove 35 can also be formed by pressing simultaneously with the concave groove 34.

  Also on the seal surface 43 of the mating flange 40, 5 to 10 or more scratch-like press grooves 45 extending in the direction along the inner periphery 41 a of the port hole 41 and parallel to each other are formed in a region in contact with the seal ring 3. doing.

  When pipes are connected using the flanges 30 and 40, the end portions of the pipes to be connected are fitted and fixed to the respective port holes 31 and 41, and the seal ring 3 is fitted into the concave groove 34 of the flange 30. . And the sealing surfaces 33 and 43 of each flange 30 and 40 are made to oppose as shown in FIG. 5, and it tightens with the volt | bolt and nut which are not shown in figure. The seal ring 3 is slightly crushed by the force, and the seal surface 33 and the seal surface 43 are brought into close contact with each other. At that time, the seal-like press groove 35 on the bottom surface of the concave groove 34 in the flange 30 and the scratch-like press groove 45 on the seal surface 43 of the flange 40 ensure that the seal ring 3 is brought into close contact with a strong frictional force, high airtightness and Water tightness is obtained.

[Fourth embodiment]
Next, a fourth embodiment of the flange for pipe connection according to the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view showing the main part of the flange together with a part of the gasket having a spring property.
The flange 50 of the fourth embodiment has a slightly larger seal surface 53, but is not shown in the region of the seal surface 53 in contact with the gasket 5 like the flanges 10 and 20 of the first and second embodiments. 5 to 10 or more scratch-like press grooves 55 extending in the direction along the inner periphery of the port hole and parallel to each other are formed.

The gasket 5 is made by punching a stainless steel plate, is formed with an annular convex surface portion 5b embossed from a flat ring-shaped base portion 5a, and has a spring property. The convex surface portion 5a of the gasket 5 is in contact with the region where the scratch-like press groove 55 of the seal surface 53 of the flange 50 is formed, and the flat surface of the base portion 5a is in contact with the seal surface of the mating flange.
Even if it does in this way, the effect similar to each above-mentioned Example is acquired.

[Fifth embodiment]
Next, a fifth embodiment of the flange for pipe connection according to the present invention will be described with reference to FIG. FIG. 7 is an enlarged cross-sectional view showing the main part of the flange together with the BGT gasket.
In the fifth embodiment, the seal surfaces 63A and 63B of the pair of flanges 60A and 60B extend in the direction along the inner periphery of the port hole (not shown) to the areas in contact with the gasket 6 and parallel to each other. More than scratch-like press grooves 65A and 65B are formed.

However, in the region where the scratch-like press grooves 65A and 65B are formed on the seal surfaces 63A and 63B of the flanges 60A and 60B, at least the portions on both sides of the scratch-like press grooves 65A and 65B are the other seal surfaces 63A and 63B. It is formed as protrusions 66A and 66B protruding from the region. In this case, the pitch and depth (the height of the ridge) of the scratch-like press grooves 65A and 65B and the ridges 66A and 66B are, for example, about 0.5 to 1.0 mm.
The gasket 6 is a gasket called “BGT gasket” whose surface has elasticity, and is such that a rubber-like material is pasted on the surface of an iron plate.

  According to this embodiment, when the flanges 60A and 60B are tightened and the seal surfaces 63A and 63B are in close contact with the gasket 6, the protrusions 66A and 66B bite into and adhere to the surface of the gasket 6, so that the air tightness is high. And watertightness are obtained.

FIG. 8 is an enlarged cross-sectional view showing a main part of a modified example of the flanges 60A and 60B.
The flange 70 has a region where the scratch-like press groove 75 is formed on the seal surface 73 slightly protruded from other regions by extrusion or thickening. Scratch-like press grooves 65A and 65B and scratch-like press grooves 75 and ridges 76 similar to the ridges 66A and 66B are alternately formed on the protruding (higher) annular surface.
If it does in this way, the surface pressure of the field in which the scratch-like press groove 75 which contacts a gasket was formed can be raised, and airtightness and watertightness can be raised further.
Furthermore, if the gasket is arranged only in the region where the scratch-like press groove 75 is formed, the cost of pipe connection can be further reduced.

[Fifth embodiment]
Next, a sixth embodiment of the flange for pipe connection according to the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view along the axial direction of a pipe at a portion where pipes are connected to each other using the flange of the sixth embodiment.
In FIG. 9, the pipe 1 </ b> A is connected to the pipe 1 </ b> B using the flange 80, the flange 90, and the seal ring 4 having a circular cross section.

The flange 80 forms a taper surface (slope) 84 having a downward slope toward the port hole 81 between the seal surface 83 and the port hole 81 into which the pipe 1A is inserted. The tapered surface 84 is a tapered surface that presses the seal ring 4 between the sealing surface 93 of the mating flange 90 and the outer peripheral surface of the mating pipe 1B. A plurality (5 to 10 or more) of scratch-like press grooves 85 extending in the direction along the inner periphery of the port hole 81 and parallel to each other are formed on the tapered surface 84.
A plurality (5 to 10 or more) of scratch-like press grooves 95 extending in the direction along the inner periphery of the port hole 91 and also parallel to each other in the region adjacent to the port hole 91 in the sealing surface 93 of the flange 90 on the other side. Is forming.

And as shown in FIG. 9, the flange 80 is welded and fixed to the outer peripheral surface of the end portion of the pipe 1A, and the flange 90 is welded and fixed to the outer peripheral surface of the end portion of the pipe 1B. The cross section of the weld is indicated by a small black triangle.
Thereafter, the seal ring 4 is fitted on the outer periphery of the end portion of the pipe 1B, held by the seal surface 93 of the flange 90, and the flange 80 is brought close to the port hole 81 until the tip end portion of the pipe 90 is fitted. The seal ring 4 is pressed at 84.

  Then, a plurality of bolts are inserted into bolt holes (not shown), nuts are attached, and tightened in the same manner as in the conventional example shown in FIG. Thereby, the taper surface 84 strongly presses the seal ring 4 against the seal surface 93 of the flange 90 and the outer peripheral surface of the pipe 1B. Therefore, the scratch-like press groove 85 on the taper surface 84 of the flange 80 and the scratch-like press groove 95 on the seal surface 93 of the flange 90 are in close contact with the surface of the seal ring 4 with a strong frictional force, and high airtightness and watertightness are achieved. can get.

  The flange 80 may be fixed to the pipe 1 </ b> A so that the tip end protrudes from the port hole 81, and the flange 90 may be fixed to the pipe 1 </ b> B so that the tip end is retracted into the port hole 91. In that case, the taper surface 84 of the flange 80 becomes a taper surface for pressing the seal ring 4 between the seal surface 93 of the mating flange 90 and the outer peripheral surface of the self-side pipe 1A.

In each of the above-described embodiments, an example in which pipes are connected to each other using a flange and a gasket or a seal ring has been described. However, a fluid such as an engine cylinder head, a pump, or a tank is used by using the flange according to the present invention. It is also possible to connect the pipe directly to a device that sucks or discharges (gas or liquid).
Note that the present invention is not limited to the above-described embodiments and modifications thereof, and various modifications, additions, omissions, combinations, and the like are possible within the scope of the claims. Of course.

1, 1A, 1B: Pipe 3, 4: Seal ring
5, 6: Gasket 5a: Base part 5b: Convex part
10, 20, 30, 40, 50, 60A, 60B, 70, 80, 90: Flange for pipe connection (flange) 10a: Top portion of planar shape 20a: Corner portions 11, 21, 31, 41, 81 of planar shape 91: Port hole
11a, 21a, 31a, 41a: inner periphery of port hole 12, 22: bolt hole 13, 23, 33.43, 53, 63A, 63B, 73: seal surface
13a, 23a, 73a: Areas 15, 25, 35, 45, 55, 65A, 65B, 75, 85, 95: Scratch-shaped press grooves 34: Concave grooves 66A, 66B, 76: Projections on the seal surface 84: Tapered surface

Claims (6)

  A flange for pipe connection for connecting the pipe in an airtight or watertight manner, and a port hole for fitting the pipe into a region in contact with the gasket on the sealing surface joined with the gasket on the other side A flange for pipe connection, wherein a plurality of scratch-shaped press grooves extending in a direction along the inner periphery and parallel to each other are formed.   2. The port hole according to claim 1, wherein the port hole is a circular port hole into which a cylindrical pipe is inserted, and the scratch-like press groove is formed uniformly in a region in contact with the gasket. Flange for pipe connection.   The port hole is a rectangular port hole into which a rectangular pipe is inserted, and each corner portion on the inner periphery of the port hole has a radius, and the scratch-like press groove is formed in each corner portion. The flange for pipe connection according to claim 1, wherein the corresponding region is formed more than the region corresponding to the straight portion.   The at least portions on both sides of each scratch-like press groove in a region where the scratch-like press groove is formed on the seal surface are formed as protrusions protruding from other regions of the seal surface. The flange for pipe connection as described in any one of 1 to 3.   A pipe connection flange for connecting a pipe in an airtight or watertight manner, and a concave groove for fitting the seal ring is fitted into a seal surface joined with the seal surface on the other side of the seal ring. A pipe connection characterized by being provided along the inner periphery of the port hole to be formed, and having a plurality of scratch-like press grooves extending in a direction along the inner periphery of the port hole and parallel to each other on the bottom surface of the concave groove Flange.   A flange for pipe connection for connecting a pipe in an airtight or watertight manner, wherein a taper surface having a downward slope toward the port hole is formed between a seal surface and a port hole into which the pipe is inserted, and the taper The surface is a tapered surface for pressing the seal ring between the mating seal surface and the outer peripheral surface of the mating or self-side pipe, and extends in a direction along the inner periphery of the port hole to the tapered surface. A flange for pipe connection, wherein a plurality of parallel scratch-like press grooves are formed.

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