JPH08246868A - Installing collar of exhaust manifold of engine for automobile - Google Patents

Abstract

PURPOSE: To enhance inserting workability of a stud bolt by forming a corner square part between a collar nut seat and an inner peripheral surface of a collar main body in a taper shape in a cylindrical installing collar to restrain thermal expansion/contraction of the installing collar by forming a clearance between the stud bolt and the collar main body. CONSTITUTION: An installing collar X is composed of a collar main body 1 and a collar nut seat 2, and restrains thermal expansion/contraction of the installing collar X by arranging a clearance between a stud bolt 6 and the collar main body 1. In this case, an end part on the collar nut seat 2 side of the collar main body 1, that is, a corner square part between an inner peripheral surface of the collar main body 1 and the collar nut seat 2 is formed in a truncated cone-shaped taper surface whose inside diameter reduces as it proceeds in the collar nut seat 2 direction, and is formed as a stud bolt guide 4. Therefore, when the installing collar X is installed on the stud bolt 6, an inserting guide of the installing collar X to the stud bolt is smoothed, and inserting workability is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting collar for an exhaust manifold of an automobile engine used when mounting an exhaust manifold on a cylinder head with a stud bolt.

[0002]

2. Description of the Related Art Conventionally, as an attachment of an exhaust manifold to a cylinder head, one shown in FIG. 6 has been known.
This will be described.

In order to attach an exhaust manifold a as shown in the figure to the cylinder head, a stud bolt c planted in the cylinder head b is passed through a bolt hole f of a flange portion e of a branch d of the exhaust manifold a. After that, a mounting collar g is attached to the stud bolt c, and finally the stud bolt nut h is generally tightened. By the way, the mounting collar g, as shown in FIG.
It is composed of a collar body i and a collar nut seat j formed at one end of the collar body i, and when the stud bolt nut h is fastened, a gap k is formed between the outer peripheral surface of the stud bolt c and the inner peripheral surface of the collar body i. To be formed.

The reason for mounting the mounting collar g is directly
When the stud bolt nut h is brought into contact with the exhaust manifold a, thermal expansion or contraction of the exhaust manifold a causes
This is because the stud bolt nut h is loosened, and the mounting collar g serves to absorb this thermal expansion or contraction. The reason for providing the gap k is that without the gap k, the radial movement range of the open end of the collar body i is limited to a smaller range due to the contact of the open end with the stud bolt c. This is because movement of the exhaust manifold a due to thermal expansion or contraction is restricted and the exhaust manifold a itself is damaged.

Therefore, from the viewpoint of providing such a gap k, in the conventional mounting collar g, the wall thickness t of the collar body i is constant over the entire length thereof.

[0006]

To mount the mounting collar g on the stud bolt c, the mounting collar g is sequentially mounted on a large number of stud bolts c so that the stud bolt c is inserted into the mounting collar g. But at this stage,
As shown in FIG. 8, the mounting collar g has a stud bolt c at the corner between the inner peripheral surface of the collar body i and the collar nut seat j.
The tip end of the abutment portion abuts, and the mounting collar g is given a turning force by its own weight with the abutment portion as a fulcrum, and its open end abuts the stud bolt c.

Therefore, in the above-described conventional example, in order to pass the tip end of the stud bolt c through the bolt hole 1 of the collar nut seat j, the mounting collar g is moved up and down and to the left and right, and so to speak, it is mounted while repeating trial and error. Color g
Had to be moved along the longitudinal direction of the stud bolt c, which made workability poor. Further, the tip portion of the stud bolt c may be caught at the corner between the collar nut seat j and the collar body i, which is also one of the factors leading to a reduction in workability.

Further, the corners between the inner peripheral surface of the collar body i and the inner surface of the collar nut seat j are formed at right angles,
Or, even if it is rounded, its radius of curvature is small, so that the rigidity of the corner portion is insufficient when the stud bolt nut h is tightened, and as shown by the dotted line in FIG.
There was a problem that the collar nut seat j was bent inward.
The present invention has been made in view of the above problems, and an object thereof is to provide a mounting collar for an exhaust manifold of an automobile engine, which improves workability in mounting the exhaust manifold and improves rigidity of a collar nut seat. And

[0009]

The present invention has the following constitution in order to achieve the above object. In the invention according to claim 1, the stud bolt implanted in the cylinder head is inserted, and when the stud bolt nut is fastened,
At least a mounting collar of a tubular automobile engine exhaust manifold having a collar nut seat of the stud bolt nut, wherein a gap is formed between an outer peripheral surface of the stud bolt and an inner peripheral surface of the collar body, A stud bolt guide is formed at a corner portion between the collar nut seat and the inner peripheral surface of the collar body, the stud bolt guide whose inner diameter at the corner portion gradually decreases in the direction of the collar nut seat.

According to a second aspect of the invention, the stud bolt guide is formed in a tapered shape. The invention according to claim 3 is characterized in that the stud bolt guide is formed over the entire length in the axial direction of the collar body.

According to a fourth aspect of the present invention, the outer peripheral surface of the collar body is formed into a tapered surface having a slope substantially equal to the slope of the stud bolt guide. The invention according to claim 5 is characterized in that the stud bolt guide has an arc-shaped cross-section.

[0012]

According to the present invention, when the mounting collar is mounted, the tip of the stud bolt of the cylinder head contacts the stud bolt guide formed on the mounting collar. With the open end of the collar body in contact with the stud bolt by the turning force given by its own weight, without moving the mounting collar up and down,
If you go straight in the longitudinal direction of the stud bolt as it is, the diameter of the stud bolt guide decreases as it goes to the collar nut seat, so the stud bolt guide automatically installs the stud bolt in the bolt hole of the collar nut seat. Is guided so that the tip of the

Further, since the stud bolt guide is provided at the corner between the collar nut seat and the inner peripheral surface of the collar body, the rigidity of the collar nut seat when the stud bolt nut is tightened is sufficient. In the invention according to claim 2, the mounting collar is guided by the tapered stud bolt guide.

According to the third and fourth aspects of the invention, the tip of the stud bolt is always in contact with the stud bolt guide of the mounting collar. In the invention according to claim 5, the mounting collar is guided by the arc-shaped stud bolt guide.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, X is a mounting collar of the exhaust manifold according to the present invention, and shows a state of being mounted on a stud bolt 6 described later. The mounting collar X shown in the figure is the mounting collar of the first embodiment shown in FIG. 2 corresponding to the invention of claim 2. Therefore, first, the mounting collar X of the first embodiment shown in the figure will be described.

The mounting collar X is composed of a collar body 1 and a collar nut seat 2. The collar main body 1 is formed in a cylindrical shape, a collar nut seat 2 is formed at one end thereof, and a bolt hole 3 is formed substantially at the center of the collar nut seat 2. The other end of the collar body 1 is open to form an open end 3a. The end portion of the collar body 1 on the side of the collar nut seat 2, that is, the corner portion between the inner peripheral surface of the collar body 1 and the collar nut seat 2 has a truncated cone whose inner diameter decreases toward the collar nut seat 2 direction. It is formed in a tapered surface.

The tapered surface constitutes the stud bolt guide 4, and the tip of the stud bolt guide 4 is continuous with the bolt hole 3. The inclination of the stud bolt guide 4 is 15 ° or less from the viewpoint of increasing the wall thickness of the corner portion between the inner peripheral surface of the collar body 1 and the collar nut seat 2, that is, the portion corresponding to the stud bolt guide 4. It is preferable to set it at 30 °.

FIG. 3 shows another embodiment of the present invention and corresponds to the third aspect of the invention. In this embodiment, the inner peripheral surface of the collar main body 1 is formed in a tapered shape over the entire length in the longitudinal direction, in other words, the inner peripheral surface of the collar main body 1 is formed in a truncated cone shape, and the entire inner peripheral surface is a stud bolt. It constitutes the guide 4a. Other configurations are similar to those of the first embodiment.

The inclination of the stud bolt guide 4a is 10 ° to 15 ° from the same reason as described above that the thickness of the corner portion is made as thick as possible and from the viewpoint that the attachment to the stud bolt 6 is made as smooth as possible. It is preferable to set to. FIG. 4 shows still another embodiment of the present invention and corresponds to the invention described in claim 4. In this embodiment, the outer peripheral surface of the collar body 1 and the outer peripheral surface of the collar nut seat 2 are also formed into tapered surfaces, and the entire mounting collar X is formed into a truncated cone shape, unlike the second embodiment. Other configurations are similar to those of the second embodiment. The gradients of the inner peripheral surface and the outer peripheral surface of the color main body 1 are equal to each other, and it is preferable that both are 10 ° to 15 °. The reason for selecting such a numerical value is to increase the deformation resistance against axial load in addition to the same reason as in the embodiment shown in FIG.

FIG. 5 shows a fourth embodiment of the present invention and corresponds to the invention described in claim 5. In this embodiment, the end portion of the collar body 1 on the collar nut seat 2 side,
That is, the corner portions of the collar main body 1 and the collar nut seat 2 are formed in a spherical surface having an arcuate cross-sectional shape, and this spherical portion constitutes the stud bolt guide 4b. Although different, the other configurations are similar to those of the first embodiment.

The radius of curvature of the stud bolt guide 4b is 3 for the same reason as in the case of the first embodiment shown in FIG.
It is preferable to set to 5 mm. in this way,
The stud bolt guides 4, 4a, 4b may have a tapered shape or an arc shape. In short, the inner diameter of the corner portion gradually decreases toward the collar nut seat 2 as in the invention of claim 1. It only has to be configured to do so.

Next, the operation of this embodiment will be described.
The case where the mounting collar X of the first embodiment shown in FIG. 2 is attached to the stud bolt 6 planted in the cylinder head 5 shown in FIG. 1 will be described as an example. First, the flange portion of the branch 8 of the exhaust manifold 7 will be described. After passing the stud bolt 6 through the bolt hole 10 formed in
The mounting collar X of the first embodiment is attached to the stud bolt 6 protruding from the.

In this case, the tip of the stud bolt 6 normally abuts on the stud bolt guide 4 of the collar body 1. However, if the collar body 1 is moved in the longitudinal direction of the stud bolt 6 as it is, the collar body 1 Guided by the stud bolt guide 4, the bolt hole 3 formed in the collar nut seat 2 reaches the tip of the stud bolt 6. Further, when the collar body 1 is moved, the tip portion of the stud bolt 6 projects from the bolt hole 3 to the outside of the collar body 1.

In the second and third embodiments, the tip of the stud bolt 6 is attached to the stud bolt guide 4a.
It always comes into contact, and in the fourth embodiment, it comes into contact with the arc-shaped stud bolt guide 4b. Finally, the stud bolt nut 11 is screwed onto the tip of the stud bolt 6 protruding from the collar body 1 and tightened.

A nut seat portion 13 having a diameter larger than the diameter of the nut body 12 is formed at one end of the stud bolt nut 11, which serves to increase the rigidity of the collar nut seat 2. When the stud bolt guides 4, 4a, 4b are provided as in the example, the thickness can be made thinner than the conventional nut seat portion, or can be omitted altogether.

In the embodiment shown in FIG. 4, the thickness of the corner portion is not so thick as compared with the other embodiments, but as described above, the mounting collar X itself has a truncated cone shape so that the axial direction is reduced. Since the deformation resistance force against the load is increased, the thickness of the nut seat portion 13 can be set to 0 and omitted. By the way, the thickness of the nut seat is 2mm in the past.
Although it was 3 mm to 3 mm, in the present embodiment, it can be 1 mm to 0 mm.

Since this embodiment is constructed as described above, when the mounting collar X is mounted on the stud bolt 6, the mounting collar X is studd so that the tip of the stud bolt 6 is inserted into the collar body 1. After the collar body 1 is attached to the bolt 6, the bolt hole 3 automatically reaches the tip portion of the stud bolt 6 only by moving the collar body 1 along the longitudinal direction of the stud bolt 6, so that workability is improved.

The stud bolt guides 4, 4 are provided at the corners between the inner peripheral surface of the collar body 1 and the collar nut seat 2.
Since a and 4b are formed, the rigidity is high, and therefore the collar nut seat 2 does not bend inward even when tightened with the stud bolt nut 11. Furthermore, as mentioned above,
Since the rigidity of the collar nut seat 2 is increased by the formation of the stud bolt guides 4, 4a, 4b, the thickness of the nut seat portion 13 of the stud bolt nut 11 can be reduced or omitted.

[0029]

Since the present invention is constructed as described above, in the invention described in claim 1, when the mounting collar is mounted on the stud bolt planted in the cylinder head, the mounting collar is the stud bolt. Since it is automatically guided by the guide, there is no need to move the mounting collar itself up, down, left or right,
Therefore, workability is improved.

Further, since the stud bolt guide has a shape in which the inner diameter is gradually reduced, no catch is generated when the stud bolt guide guides the mounting collar, so that the work proceeds smoothly. In addition, the rigidity of the collar nut seat is improved by forming the stud bolt guide at the corner between the inner peripheral surface of the collar body and the collar nut seat. There is no way to go along.

Further, since the rigidity of the collar nut seat is improved, the thickness of the stud bolt nut can be reduced or omitted. In the invention according to claim 2, since the stud bolt guide is formed in a tapered shape, the guide of the mounting collar by the stud bolt guide becomes smoother.

According to the third aspect of the present invention, since the stud bolt guide is formed over the entire length of the collar body, the mounting collar can be smoothly guided regardless of which part of the collar body the tip end of the stud bolt abuts. Will be. In the invention according to claim 4, since the collar body itself is formed in a tapered shape, the spring force of the collar body is increased, and as a result, a strong tightening force is obtained when the stud bolt nut is fastened. .

In the invention according to claim 5, since the stud bolt guide is formed in an arcuate cross section, the guide of the mounting collar by the stud bolt guide becomes smoother and the rigidity of the collar nut seat increases.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a mounting state of a mounting collar according to a first embodiment of the present invention.

FIG. 2 is likewise a side sectional view of the mounting collar.

FIG. 3 is a side sectional view of a mounting collar according to the second embodiment of the present invention.

FIG. 4 shows a third embodiment of the present invention and is a side sectional view of a mounting collar.

FIG. 5 is a side sectional view of a mounting collar according to the fourth embodiment of the present invention.

FIG. 6 is a front view showing a conventional exhaust manifold.

FIG. 7 is a sectional view showing a mounting state of a conventional mounting collar.

FIG. 8 is an operation explanatory view showing a mounting state of a conventional mounting collar.

[Explanation of symbols]

 1 Color Body 2 Color Nut Seat 4, 4a, 4b Stud Bolt Guide 5 Cylinder Head 6 Stud Bolt 7 Exhaust Manifold 11 Stud Bolt Nut X Mounting Collar

Claims (5)

[Claims] 1. A stud in which a stud bolt implanted in a cylinder head is inserted and a gap is formed between an outer peripheral surface of the stud bolt and an inner peripheral surface of the collar body when the stud bolt nut is fastened. In a mounting collar of an exhaust manifold of a tubular automobile engine provided with a collar nut seat of a bolt nut, at least a corner portion between the collar nut seat and the inner peripheral surface of the collar body has an inner diameter at the corner portion. A collar for mounting an exhaust manifold of an automobile engine, which is formed with a stud bolt guide that gradually decreases in the direction of the collar nut seat. 2. The exhaust manifold mounting collar for an automobile engine according to claim 1, wherein the stud bolt guide is formed in a tapered shape. 3. The mounting collar for an exhaust manifold of an automobile engine according to claim 2, wherein the stud bolt guide is formed over the entire length of the collar body in the axial direction. 4. The exhaust manifold of an automobile engine according to claim 3, wherein an outer peripheral surface of the collar body is formed as a tapered surface having a slope substantially equal to a slope of the stud bolt guide. Mounting color. 5. The mounting collar for an exhaust manifold of an automobile engine according to claim 1, wherein the stud bolt guide has an arc-shaped cross-section.