JPH04295125A - Clamp structure for exhaust manifold - Google Patents

Abstract

PURPOSE:To improve sealing performance by increasing a sealing area by a clamp. CONSTITUTION:A clamp 8 is formed into an approximately C shape, and its section is made a recessed shape suited to the installation surfaces of flanges 3a, 4a. A bolt hole 10 is formed at both clamping parts 8a, 8b of a clamp 8, and a bolt 9 is fitted into the bolt hole 10 and is tightened by a nut 11. A spacer 12 is formed between both the clamping parts 8a, 8b. A tapered surface 9d is formed at a shaft part 9b of the bolt 9, and a tapered surface 12c is formed at a bolt hole 12b of the spacer 12 in the same way. By tightening the bolt 9 and the nut 11, both the tapered surfaces 9d and 12c are made to come into contact with each other so as to move the spacer 12 in a central direction of the clamp 8. It is thus possible to tighten and seal mated members of respective flanges 3a, 4a or the like at a clearance G between both the clamping parts 8a and 8b movement of the spacer 12.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to an exhaust manifold that guides exhaust gas discharged from an engine to a muffler, etc.
More specifically, the present invention relates to a clamp structure for connecting pipes in the exhaust manifold.

0002

[Prior Art] Conventionally, as this type of technology, for example, FIG.
A C-shaped clamp 21 as shown in FIG. 1 is generally known. This clamp 21 is used to attach the end of a separate pipe line to the flange portion 22 of the exhaust manifold. The inner circumferential surface 21a of this clamp 21 has a concave shape corresponding to the clamp mounting surface between the flange portion 22 of the exhaust manifold and the end of the separate pipe line. And that C
By tightening both end tightening portions 21b and 21c of the shape clamp 21 with bolts 23 and nuts 24, the flange portion 22 and the end of another conduit are connected.

0003

However, in the conventional technique, there is a gap G between the two tightening parts 21b and 21c of the clamp 21, and in this gap G, the flange part 2
It was not possible to directly tighten the 2nd class with the clamp 21. Therefore, only the part of the gap G is covered by the clamp 21.
As a result, the tightening force was weak and the sealing performance was insufficient, leading to the risk of problems such as gas leakage.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a clamp structure for an exhaust manifold that can increase the sealing range of the C-shaped clamp and improve sealing performance. It is in.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention has a structure in which the flange portion of an exhaust manifold and another pipe line are connected by a clamp, and the clamp has a substantially C shape. The cross section of the clamp has a concave shape corresponding to the mounting surface of the flange part, and bolt holes are formed in the tightening parts at both ends of the clamp.
In an exhaust manifold clamp structure in which a bolt is installed in the bolt hole and tightened with a nut, a spacer is provided between the tightening parts at both ends of the clamp, which can be moved toward the center of the clamp by tightening the bolt and nut. .

[0006]

[Operation] According to the above configuration, when connecting the flange of the exhaust manifold and the end of a separate pipe line, the clamp is attached and the bolts and nuts are inserted between the clamping parts at both ends. tighten. At this time, the mating member is tightened by the inner circumferential surface of the clamp, and the spacer moves toward the center of the clamp between the two tightening portions, thereby pressing the mating member. Therefore, the mating member is tightened even in the gap between the two tightening portions, and that portion is sealed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the exhaust manifold clamp structure of the present invention will be described in detail below with reference to FIGS. 1 to 4. FIG. 4 is a plan view showing an exhaust manifold 1 applied to an in-line six-cylinder supercharged gasoline engine system mounted on an automobile. This exhaust manifold 1 guides exhaust gas discharged from each cylinder #1 to #6 of the engine 2 to the supercharger. They are grouped into two cylinder groups #4 to #6 without cylinders. That is, the exhaust manifold 1 includes a main exhaust collecting section 3 and a sub-exhaust collecting section 4, and both the exhaust collecting parts 3 and 4 are communicated with each other through a communication passage 5.

In this embodiment, the supercharger has two turbochargers (not shown), a main and a sub-turbocharger.
It is configured as a 2-stage twin-turbo system. The main turbocharger is operated from the low intake air volume range of engine 2 to the high intake air volume range, and the auxiliary turbocharger is stopped in the low intake air volume range of engine 2, and is operated only in the high intake air volume range of engine 2. It has become. The turbine of the main turbocharger is communicated with the main exhaust collecting section 3, and the turbine of the sub-turbocharger is communicated with the sub-exhaust collecting section 4. When only the main turbocharger is operated, the exhaust gas from one cylinder group #1 to #3 flows to the main turbocharger through the main exhaust collecting section 3, and the exhaust gas from the other cylinder group #4 to #6 flows to the main turbocharger. Gas reaches the main exhaust collecting part 3 from the sub-exhaust collecting part 4 through the communication passage 5, and then flows to the main turbocharger. Furthermore, when both the main and auxiliary turbochargers are operated, the exhaust gas from one cylinder group #1 to #3 flows through the main exhaust collecting section 3 to the main turbocharger, and the exhaust gas from the other cylinder group #4 to #3 flows to the main turbocharger. Exhaust gas from 6 flows through a sub-exhaust collecting section 4 to a sub-turbocharger.

The middle of the communication path 5 is separated into a main exhaust collecting section 3 and a sub-exhaust collecting section 4, and the separated parts are connected by a flexible connecting means 6. This connecting means 6 includes an inner pipe and a flexible pipe 7 (not shown).
and a pair of left and right clamps 8. The flange portions 3a, 4a (shown in FIG. 1) of the respective exhaust gas collecting portions 3, 4 and the end portions of the flexible pipes 7 are connected by respective clamps 8. Here, the flexible pipe 7 is connected to each exhaust collecting section 3 that is generated due to the high heat of the exhaust gas.
, 4 is provided to absorb thermal expansion. The flexible pipe 7 is obtained by forming a stainless steel thin plate material with excellent corrosion resistance and heat resistance into a bellows shape, and is elastically deformable.

Next, the clamp structure of the above-mentioned connecting means 6 will be explained. As shown in FIGS. 1(A) and 1(B), the clamp 8 is formed into a substantially C-shape. A pair of clamping parts 8a and 8b are formed at both ends of the clamp 8 and extend in parallel in the radial direction, and a gap G is formed between the clamping parts 8a and 8b. A bolt hole 10 for mounting a tightening bolt 9 is formed in each tightening portion 8a, 8b. This clamp 8 is configured such that one bolt 9 is mounted in both bolt holes 10 and tightened with a nut 11. Further, an inner circumferential groove 8c having a concave shape corresponding to the mounting surface of each flange portion 3a, 4a of each exhaust collecting portion 3, 4 is formed on the inner circumference of the clamp 8.

In this embodiment, a spacer 12 is provided between the clamping portions 8a and 8b of the clamp 8, and is movable toward the center of the clamp 8 by tightening the bolt 9 and nut 11. In this embodiment, the spacer 12 is made movable by setting the shapes of the bolt 9 and the spacer 12. That is, as shown in FIGS. 2(A) and 2(B),
One side of the shaft portion 9b extending from the bolt head 9a of the bolt 9 has a tapered surface 9d converging toward the threaded portion 9c at the tip.
It becomes. On the other hand, as shown in FIGS. 3(A) and 3(B), the spacer 12 has a rectangular parallelepiped shape, and its inner surface 12a
is a circular arc surface corresponding to the outer peripheral surface of a mating member such as the flange portions 3a, 4a of each exhaust collecting portion 3, 4. Further, a bolt hole 12b for inserting the bolt 9 is formed in the center of the spacer 12. And this bolt hole 1
2b has a tapered surface 12c on one side of its inner periphery so as to match the tapered surface 9d of the shaft portion 9b of the bolt 9.

Therefore, as shown in FIGS. 1 and 4, when connecting the flange portions 3a, 4a of each exhaust collection portion 3, 4 to the end of the flexible pipe 7, a clamp 8 is attached and both of the flange portions 3a, 4a are connected. The bolt 9 and nut 11 are tightened with a spacer 12 interposed between the tightening parts 8a and 8b. At this time, the inner circumferential groove 8c of the clamp 8 tightens the respective flange parts 3a, 4a and the end of the flexible pipe 7, which are the mating members, and the mating surfaces of these members 3a, 4a, 7 can be brought into close contact. .

At the same time, between the two tightening parts 8a and 8b, the bolt 9 having a tapered surface 9d and the spacer 12 having a tapered surface 12c fit together, so that the spacer 12 is centered on the clamp 8. direction, and the flange portions 3a, 4a and the end of the flexible pipe 7 are pressed. That is, as the bolt 9 and nut 11 are tightened, the shaft portion 9b and the tapered surfaces 9d and 12c of the bolt hole 12b come into contact with each other, and the spacer 12 is guided toward the center of the clamp 8 with a pressing force. As a result, even in the gap G between the two tightening parts 8a, 8b, the flange parts 3a, 4a and the flexible pipe 7
This allows the mating surface to be brought into closer contact with the end of the material, resulting in a seal. In other words, the sealing performance can be ensured even in the gap G, and the sealing range of the clamp 8 as a whole can be expanded, thereby improving the sealing performance.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be practiced by changing a part of the structure as appropriate without departing from the spirit of the invention. For example, in the embodiment described above, the clamp structure is implemented in the communication passage 5 of the exhaust manifold 1, but it can also be implemented simply in a clamp structure between the outlet side of the exhaust manifold and another pipe line such as a manifold converter. Alternatively, the shapes of the bolt 9 and the spacer 12 are not limited to the above embodiments,
It can also be changed as appropriate.

[0015]

As described in detail above, according to the present invention, a spacer is provided between the tightening portions at both ends of the clamp, which is formed into a substantially C shape and is movable toward the center of the clamp by tightening bolts and nuts. Therefore, the spacer can tighten the gap between the two clamping parts, increasing the sealing range by the clamp, and thereby exhibiting an excellent effect of improving sealing performance.

[Brief explanation of drawings]

FIG. 1 shows a clamp structure in an embodiment embodying the present invention, in which (A) is a front view thereof, and (B) is a side view thereof.

FIG. 2 (A) is a front view of a bolt in one embodiment;
B) is also a bottom view of the bolt.

FIG. 3 (A) is a front view of a spacer in one embodiment;
(B) is a plan view of the spacer as well.

FIG. 4 is a plan view showing an exhaust manifold applied to an in-line six-cylinder turbocharged gasoline engine system in one embodiment.

FIG. 5 is a front view showing a conventional clamp structure.

[Explanation of symbols]

1...Exhaust manifold 3a, 4a...flange part 7... Flexible pipe as another conduit 8... Clamp 8a, 8b...Tightening part 9...Bolt 11...Nut 12...Spacer 9d, 12c...Tapered surface G...Gap

Claims (1)

[Claims] 1. A structure in which a flange of an exhaust manifold and another pipe are connected by a clamp, the clamp having a substantially C shape, and a cross section of the clamp corresponding to a mounting surface of the flange. In the clamp structure of the exhaust manifold, which has a concave shape and has bolt holes formed in the clamping parts at both ends of the clamp, and bolts are installed in the bolt holes and tightened with nuts, between the clamping parts at both ends of the clamp, A clamp structure for an exhaust manifold, characterized in that a spacer is provided that can be moved toward the center of the clamp by tightening the bolt and the nut.