JP3817713B2 - Friction welding surface shape of exhaust manifold and catalyst case - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to the shapes of friction welding surfaces of an exhaust manifold and a catalyst case .
[0002]
[Prior art and problems]
Conventionally, for example, as shown in FIG. 7, when the exhaust manifold 1 and the catalyst case 2 are joined by friction welding, the exhaust manifold 1 and the catalyst case 2 are fixed to the set jigs 3 and 4, respectively, and brought into contact with the pressure contact surface P as shown in FIG. First, as shown in FIG. 10, a rotation is applied to the catalyst case 2 side to perform a rubbing step, and the pressure contact surface P is slid by the predetermined pressure and the number of rotations.
In this rubbing step, the pressure contact surface P is made uniform and brought into contact with the entire surface, and in the friction step, the pressure and the number of rotations are increased to generate frictional heat on the pressure contact surface P. In the upset process, which is the final process after generating the softened layer, the rotation is stopped, a high pressure is applied, and a part of the molten layer and the softened layer is discharged and joined, and the process proceeds to the friction process. The stable state of the pressure contact surface P at the time was a necessary condition for obtaining a good friction pressure welding.
[0003]
However, in the case where the exhaust manifold 1 and the catalyst case 2 are formed of a casting material, the material falls off from the brittleness of the casting material at the beginning of the rubbing process, as shown in FIG. There is a problem that wear powder M is generated on the pressure contact surface P, the pressure contact surface P becomes like rolling friction, heat generation becomes unstable, and the state of the pressure contact surface P is not stable when moving to the friction process. It was.
In addition, since such wear powder M has a large surface area with respect to the volume, if the wear powder M exists on the pressure contact surface P for a long time, it is easy to generate an oxide, and the oxide is higher than the melting point of the metal and the metal. Therefore, it remains on the pressure contact surface P without being decomposed, and a good joint surface cannot be obtained, and the presence of the oxide reduces the depth of the softened layer during the friction process, and the upset process. There is a problem in that the length of the product shape after joining varies due to the change in the shift margin.
In order not to generate such wear powder M, the surface roughness of the pressure contact surface P is processed smoothly and accurately, the accuracy of the perpendicularity of the pressure contact surface P with respect to the set jigs 3 and 4 is increased, and the processing accuracy is increased. There is a problem that it takes a long time for processing and increases the cost.
[0004]
[Means for Solving the Problems]
The present invention has been devised in view of the above-mentioned conventional problems, and is a friction welding surface between the exhaust manifold and the catalyst case that discharges the abrasion powder well and the pressure contact surface comes into full contact with each other to obtain a good joined state. intended to not provide shape, Abstract of its, after being combined sliding in ground-step, in pressure contact surface of the exhaust manifold and catalyst case which is melted by friction step, to discharge abrasion powder generated during the break-step For the sake of simplicity , the pressure contact surface is formed with a cutting groove penetrating from the inside to the outside over the entire circumference, and the cutting groove is formed in a direction intersecting the sliding direction during the rubbing step, and The depth is set so that it disappears before moving to the friction process .
[0005]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a state diagram when the exhaust manifold 1 and the catalyst case 2 are joined by friction welding. A boss portion 1a is formed on the outer periphery of the exhaust manifold 1, and is clamped by a fixing jig 3 from the outside. The boss portion 2a is formed on the outer periphery of one catalyst case 2 and the boss portion 2a is clamped and fixed from the outside with the fixing jig 4, and the catalyst case 2 side is fixed as described above. As shown in FIG. 2, a cutting groove 5 penetrating from the inside toward the outside is formed on the entire circumference of the pressure contact surface P of the catalyst case 2 as shown in FIG. The cutting groove 5 is formed in a direction intersecting the sliding direction of the pressure contact surface P in the grinding process, and the depth of the cutting groove 5 is such that it does not disappear during the grinding process. Formed in the form of cutting marks Has become a thing was.
The pressure contact surface P of the exhaust manifold 1 on one side is processed smoothly.
[0006]
As shown in FIG. 3, when the pressure contact surface P between the exhaust manifold 1 and the catalyst case 2 is set so as not to cause misalignment, the catalyst case 2 side is rotated, and the alignment process is performed, the wear that occurs during the alignment process The powder M falls off into the cutting groove 5, and the abrasion powder M is discharged to the outside along the cutting groove 5 due to the centrifugal force generated by the rotation of the catalyst case 2 as shown in FIG. The cutting groove 5 disappears due to wear, and at that time, the pressure contact surface of the exhaust manifold 1 and the pressure contact surface of the catalyst case 2 are in contact with each other.
[0007]
That is, at this stage, the metal is in contact with the metal in the vicinity of the center portion of the pressure contact surface P, and there is no generation of oxide due to the presence of wear powder M as in the prior art. In a friction process, the frictional heat is uniformly generated over the entire surface of the pressure contact surface P, and a melted layer and a softened layer having a certain depth are generated satisfactorily in the friction process. A part of the layer and the softened layer can be discharged well, and in the state where no oxide is present, the joining of the exhaust manifold 1 and the catalyst case 2 can be completed at the set margin.
[0008]
Since the cutting grooves 5 for discharging the abrasion powder are formed in this way, it is not necessary to process the pressure contact surface as smoothly as in the conventional case, and the setting accuracy of the fixing jigs 3 and 4 is as precise as in the conventional case. Since this is not necessary, the fixing boss portion 2a can be omitted, and the processing cost can be reduced.
The cutting groove may be a cross-hatched cutting groove 5a as shown in FIG. 5, and wear powder can be discharged to the outside through the cross-hatched cutting groove 5a.
Such a cross-hatched cutting groove 5a can be cut using a cutter 6 as shown in FIG. 6, and can be easily processed by setting the diameter and feed speed of the cutter 6. It will be a thing.
[0009]
【The invention's effect】
In the present invention, the pressure contact surface of the exhaust manifold and the catalyst case melted in the friction process after being rubbed together in the friction process, the wear surface generated at the time of the friction process is easily discharged. A cutting groove penetrating from the outside to the outside is formed over the entire circumference, and the cutting groove is formed in a direction intersecting the sliding direction at the time of the rubbing process, and disappears before moving to the friction process. By setting the depth, the wear powder generated during the grinding process can be discharged to the outside along the cutting groove well by using centrifugal force , eliminating the generation of oxide by the wear powder , When moving to the friction process, the pressure contact surface is in full contact, and the entire friction surface is uniformly melted, and the exhaust manifold and catalyst case are formed of a casting material. It becomes capable of obtaining the bonded state.
[Brief description of the drawings]
FIG. 1 is an arrangement configuration diagram in a state where an exhaust manifold and a catalyst case are clamped and a pressure contact surface is brought into contact with each other.
FIG. 2 is a perspective configuration diagram in which a cutting groove is formed on a pressure contact surface of a catalyst case.
FIG. 3 is an arrangement configuration diagram before starting a rubbing process.
FIG. 4 is an operation explanatory view in which wear powder generated during the rubbing step is discharged to the outside along the cutting groove.
FIG. 5 is a perspective configuration diagram showing another example of a cutting groove.
6 is a schematic plan configuration diagram in which the cutting groove of FIG. 5 is cut by a cutter. FIG.
FIG. 7 is an arrangement configuration diagram of a conventional friction welding member.
FIG. 8 is a schematic configuration diagram of a starting state of conventional friction welding.
FIG. 9 is a schematic state diagram in which wear powder has been generated in the pasting process.
FIG. 10 is a diagram showing the relationship between the shift margin due to friction welding, the pressure, and the rotational speed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Exhaust manifold 1a Boss part 2 Catalyst case 3, 4 Fixing jig 5 Cutting groove 5a Cross hatched cutting groove 6 Cutter P Pressure-contact surface M Wear powder

Claims (1)

After being rubbed together in the rubbing process, the pressure contact surface of the exhaust manifold and catalyst case melted in the friction process penetrates the pressure contact surface from the inside to the outside so that it is easy to discharge wear powder generated during the rubbing process. The cutting groove is formed over the entire circumference, and the cutting groove is formed in a direction that intersects the sliding direction during the rubbing process, and is set to a depth that disappears before moving to the friction process. friction welding surface shape of the exhaust manifold and the catalyst casing, characterized in that it is.

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