JP2874059B2 - Exhaust manifold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust manifold mounted on a vehicle exhaust system.

[0002]

2. Description of the Related Art In a vehicle exhaust system, an exhaust manifold for sending exhaust gas discharged from an engine into a single line to a silencer is attached to a cylinder head of the engine.
Conventionally, an exhaust manifold has been disclosed in Japanese Patent Application Laid-Open No. 63-17914.
No. 2 disclosed in Japanese Patent Publication No.
As disclosed in JP-A-39529, an exhaust manifold made of a pipe which is lighter than a cast product and has less air resistance on the inner surface is used.

FIG. 4 shows a conventional example of an exhaust manifold made of pipes. In the figure, reference numeral 1 denotes an exhaust manifold mounted on an in-line four-cylinder engine.
Are stainless steel pipes 3 whose ends are bent in a substantially L-shape, three short stainless steel pipes (branch pipes) 5, 7, 9 connected to the peripheral wall of the pipe 3, and each pipe 5. , 7, 9, 3 and head-side flanges 11, 13, 15, 17 connecting pipes 5, 7, 9, 3 to respective exhaust ports of the cylinder head. The downstream side of the pipe 3 is connected to a front tube via a flange 19.

The pipes 5, 7, 9, 3 and the head flanges 11, 13, 15, 17 are attached to the pipe mounting holes of the head flanges 11, 13, 15, 17, respectively. 5, 7, 9, and 3 are inserted, and welding is performed between their tips and the pipe mounting holes. In addition, each of the head-side flanges 11, 13, 1
5 and 17, flange mounting holes for mounting the exhaust manifold 1 to the cylinder head are provided one above and below each pipe mounting hole, but in the conventional exhaust manifold 1, FIG. As shown in FIG. 5, for example, the upper flange mounting hole of the head side flange 13 connected to the second exhaust port is a reference hole 23 slightly larger than the diameter of the stud bolt 21 implanted in the cylinder head.
The other flange mounting holes 25 are so-called fool holes that are larger in diameter than the reference holes 23 in consideration of thermal deformation (thermal shrinkage) of each of the head-side flanges 11, 13, 15, and 17.

Then, the pipes 3, 5, 7, 9 are made to correspond to the respective exhaust ports of the corresponding cylinder head, and the stud bolts 21 are inserted into the reference holes 23 and the flange mounting holes 25, and these are connected with nuts. By tightening
The exhaust manifold 1 is mounted on the engine.

[0006]

However, the exhaust manifold 1 has a flange 19 on the head side flange 17 side.
Side and the flange mounting holes 25 are formed as fool holes as described above.
At the time of mounting, the exhaust manifold 1 rotates counterclockwise about the stud bolt 21 inserted into the reference hole 23 as a rotation center. As a result, as shown by the broken line in FIG. There was a risk of being mounted. If the exhaust manifold 1 shifts and is mounted on the engine in this manner, there is a possibility that the exhaust system on the downstream side of the exhaust manifold 1 cannot be mounted or the exhaust system is twisted and mounted on the vehicle.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide an exhaust manifold in which the engine can be mounted at a regular position and the mountability of an exhaust system is improved. is there.

[0008]

In order to achieve the above object, the present invention provides a single L-shaped bent end.
Connected to the pipe (3) and the peripheral wall of the pipe (3)
Three short pipes (5, 7, 9) and the pipe (3)
A flange (19) attached to the downstream end of the path
The bent tip of Ip (3) and each pipe (5,
Head-side flange attached to the tip of 7, 9)
(17, 29, 13, 15).
Flags provided above and below the lunges (17, 29, 13, 15)
Engine mounting head (25) into the engine cylinder head exhaust hole.
Stud bolts implanted in the air manifold mounting area
(21) and insert it into the stud bolt (21).
With an exhaust manifold attached to the engine
Then, insert one of the flange mounting holes (25)
Reference hole (23) slightly larger in diameter than dobolt (21)
And the other flange mounting holes (25)
Made of a pipe with a fool hole larger in diameter than the bolt (21)
Formed as a fool hole in the exhaust manifold
Connect one of the flange mounting holes (25) with a stud bolt (2
1) having a minor diameter width (n) larger than the diameter of the reference hole;
(23) and the flange hole on the same side as the reference hole (23)
Center of stud bolt (21) inserted into attachment hole (25)
The center line (m) connecting the points (o) or the reference hole (23)
Stud bolt inserted into each flange mounting hole (25) on the opposite side
Parallel to the center line (p) connecting the center point (o) of the rut (21)
Slot (33) formed in the exhaust manifold (2
7) At the time of attachment, one edge (33a,
33b) comes into contact with the stud bolt (21) and the reference hole
Rotating stud bolt (21) inserted in (23)
Do not restrict the rotation of the exhaust manifold (27)
It is characterized by that.

[0009]

According to the present invention, in order to attach the exhaust manifold to the cylinder head of the engine, the stud bolts implanted in the cylinder head are inserted into each of the flange attachment holes, the reference holes, and the long holes, and then the nuts are attached to the stud bolts. What is necessary is just to screw and tighten these. At this time, the stud bolt contacts the edges of the reference hole and the long hole to support the exhaust manifold, and the long hole suppresses rotation of the exhaust manifold to prevent displacement of the exhaust manifold. And
Deformation due to thermal contraction of the head-side flange after mounting is such that the flange mounting holes and the long holes absorb such thermal deformation.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. The same components as those of the conventional example shown in FIGS. 4 and 5 are denoted by the same reference numerals. In FIG.
Is an exhaust manifold made of a pipe mounted on an in-line four-cylinder engine.
Stainless steel pipe 3 bent in a letter shape, three short stainless steel pipes (branch pipes) 5, 7, 9 connected to the peripheral wall of the pipe 3, and each pipe 5, 7, 9, 9,
3 and head side flanges 29, 13, 15, 17 for connecting the pipes 5, 7, 9, 3 to the respective exhaust ports of the cylinder head. The downstream side of the pipe 3 is connected to a front tube via a flange 19.

Thus, each of the head side flanges 29, 1
2, 3, and 17, a reference hole 23 is formed on the head side flange 13 fixed to the tip of the pipe 7 on the upper side of the pipe mounting hole 31 as shown in FIG. Further, a flange mounting hole 25 having a diameter larger than the reference hole 23 is formed in a lower portion, and further, the head side flanges 15 fixed to the tips of the pipes 9 and 3, respectively.
17, a flange mounting hole 25 is formed vertically above and below the pipe mounting hole. On the other hand, among the upper and lower rows of stud bolts 21 implanted in the cylinder head, as shown in FIG. 2, the center of the upper stud bolt 21 is fixed to the head side flange 29 fixed to the tip of the pipe 5. The elongated hole 33 has a width n substantially equal to the diameter of the flange mounting hole 25 in place of the flange mounting hole 25 provided above the head-side flange 11 shown in FIG. It is formed. The long hole 33 absorbs the thermal deformation of the head side flange 29, and when the exhaust manifold 27 is attached, the outer periphery of the stud bolt 21 comes into contact with the upper edge 33 a of the long hole 33, and the reference hole 23. The rotation of the exhaust manifold 27 around the stud bolt 21 inserted into the exhaust manifold 27 in the direction of arrow A is restricted. In addition, in FIG. 2, reference numeral 35 is a pipe mounting hole provided in the head-side flange 29.

Since the present embodiment is constructed as described above, the head-side flanges 29, 13, 15, 1 as described above are used.
In order to attach the exhaust manifold 27 in which the pipe 7 is fixed to the end of each of the pipes 5, 7, 9, 3 to the cylinder head of the engine, the pipes 3, 5, 7, 9 are matched with the respective exhaust ports of the corresponding cylinder head. After the stud bolts 21 are inserted into the flange mounting holes 25, the reference holes 21, and the elongated holes 33, nuts may be screwed onto the stud bolts 21 and tightened. Then, at this time, as shown in FIG.
The exhaust manifold 27 is supported in contact with the upper edge 33a, and the upper edge 33a suppresses rotation of the exhaust manifold 27 in the direction of arrow A to prevent the exhaust manifold 27 from tilting.

After the exhaust manifold 27 is mounted,
Each of the head-side flanges 29, 13, 15, and 17 is deformed by heat shrinkage, and the heat deformation is absorbed by the flange mounting holes 25 and the long holes 33 formed as fool holes. Therefore, according to the present embodiment, the exhaust manifold 27
At the time of mounting, the exhaust manifold 27 is turned to the arrow A as in the prior art.
As a result, the exhaust system on the downstream side is prevented from being twisted, whereby the exhaust system including the exhaust manifold 27 can be accurately mounted at a proper position. Further, according to this embodiment, the slot 33 is
Since it was formed with the same minor diameter width n as the diameter of the flange mounting hole 25,
The stud bolt 21 can be easily inserted into the long hole 33,
The workability of assembling the exhaust manifold to the
There is no hindrance.

It should be noted that the present invention is not limited to the above embodiment, and the head side flange 17 shown in FIG.
As shown in FIG. 3, the center of the lower stud bolt 21 of the upper and lower two rows of stud bolts 21 implanted in the cylinder head is located below the flange mounting hole 25 and the pipe mounting hole 37 provided in the upper part. An elongated hole 33 parallel to the line p connecting the point o is provided.
The head side flange 39 may be formed so that the outer periphery of the stud bolt 21 abuts on the lower edge 33b of the third stud.

According to the exhaust manifold in which the head-side flange 39 is fixed to the end of the pipe 3, the outer periphery of the stud bolt 21 comes into contact with the lower edge 33b of the long hole 33 when the exhaust manifold is attached. The rotation of the exhaust manifold in the direction of arrow B about the center of rotation of the stud bolt 21 inserted into the reference hole 23 is restricted. Therefore, according to this embodiment, similarly to the above-described embodiment, when the exhaust manifold is mounted, the exhaust manifold is connected to the reference hole 2 as in the related art.
3 does not tilt around the stud bolt 21 inserted, so that the intended purpose can be achieved.

[0016]

[0017]

As described above , according to the present invention, the exhaust gas
When the manifold is installed, the exhaust manifold is
Can be tilted around the stud bolt inserted into the reference hole.
As a result, the exhaust system on the downstream side may be twisted.
And the exhaust system can be correctly mounted in the correct position.
It has become possible. Further, according to the present invention, the elongated hole is formed with a flange.
Since it is formed with the same minor diameter width as the diameter of the perforated hole,
Head bolts are easy to insert, and the exhaust
It does not hinder assembly workability of the manifold.
No.

[0018]

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an exhaust manifold according to one embodiment of the present invention.

FIG. 2 is an enlarged view of a head-side flange of the exhaust manifold shown in FIG.

FIG. 3 is an enlarged view of a head-side flange of an exhaust manifold according to another embodiment of the present invention.

FIG. 4 is an overall perspective view of a conventional exhaust manifold.

FIG. 5 is a partially enlarged view of the exhaust manifold shown in FIG.

[Explanation of symbols]

 3, 5, 7, 9 Pipe 13, 15, 17, 29, 39 Head side flange 21 Stud bolt 23 Reference hole 25 Flange mounting hole 27 Exhaust manifold 33 Slot

Claims (1)

(57) [Claims] 1. A single tip having a substantially L-shaped bent end
Pipe (3) and three short pipes connected to the peripheral wall of the pipe (3)
(5, 7, 9) and a flange attached to the downstream end of the pipe (3)
(19), the bent tip of the pipe (3) and each pipe
(5, 7, 9)
(17, 29, 13, 15), and the upper and lower sides of each head-side flange (17, 29, 13, 15).
Into the flange mounting hole (25)
A switch implanted in the exhaust manifold attachment site of Dahead
Insert the stud bolt (21), screw a nut to the stud bolt (21), and
An exhaust manifold mounted on the flange, wherein one of the flange mounting holes (25) is provided with a stud bolt.
A reference hole (23) slightly larger in diameter than (21) is formed, and the other flange mounting holes (25) are provided with the stud bolts.
(21) Exhaust made of pipe with a fool hole larger in diameter than
In the manifold, one of the flange mounting holes (25) formed as fool holes
One of the minor diameter widths (n) larger than the diameter of the stud bolt (21)
And the reference hole (23) and the same hole as the reference hole (23)
Stud bolt (2) inserted into the flange mounting hole (25)
Center line (m) connecting the center point (o) of 1) or reference hole
Insert into each flange mounting hole (25) on the opposite side to (23).
Center line connecting the center points (o) of the stud bolts (21)
(P), and one edge (33a, 33b) of the elongated hole (33) is stuck when the exhaust manifold (27) is attached.
Abut on the bolt (21) and insert it into the reference hole (23).
Exhaust manifold centered on the stud bolt (21)
Characterized in that the rotation of the hold (27) is regulated.
Pipe exhaust manifold.