JPH02120129A - Balance weight mounting structure for light alloy propeller shaft - Google Patents

Abstract

PURPOSE:To aim at the promotion of simplification for installation and of miniaturization for a balance weight by supporting this balance weight, consisting of a high specific gravity material, on a light alloy properller shaft body via a support pin consisting of the same material with this body. CONSTITUTION:A steel balance weight 3 is attached to a requisite balancing part on an outer surface in a ring propeller shaft body 1 made of aluminum via an aluminum stud pin 2. At this time, in this stud pin 2, there are provided with a large diametral part 2a and a small diametral part 2b at both the upper and lower parts. The large diametral part 2a is embedded in the balance weight 3, while the small diametral part 2b is welded to a well surface of the shaft body 1 through a clearance of a specified size B. In addition, the balance weight 3 is set up at a specified interval to a surface of the shaft body 1. With this constitution, welding of the balance weight 3 is made so easy and simultaneously its weight is made larger and its volume is made smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a balance weight mounting structure for balancing the rotation of a propeller shaft, and specifically relates to a balance weight mounting structure when a light alloy material is used as the propeller shaft. It's about structure.

(Prior Art) Adjustment of the rotational balance of a propeller shaft of an automobile or the like is generally performed by welding a balance weight to the propeller shaft body in consideration of ease of manufacture. Since steel has generally been used as the material for forming propeller shafts, the balance weight is also made of steel, and this is attached to the balancing part of the propeller shaft body by projection welding to adjust the rotational balance. I was doing it.

On the other hand, recently, for the purpose of reducing the weight of propeller shafts, it has become known that the main body of the propeller shaft is made of light alloy metal such as aluminum, and such propeller shafts are similar to the steel propeller shafts mentioned above. It is necessary to adjust the rotational balance.

(Problems to be Solved by the Invention) However, when the propeller shaft body is made of aluminum, it is technically difficult to weld a steel balance weight directly to the shaft body, and if the balance weight is made of aluminum, Aluminum has a light specific gravity of about 1/3 compared to steel, so it inevitably has a large volume, which causes the weight to be dispersed, resulting in poor balance efficiency and problems such as the balance weight protruding too far in the radial direction of the shaft. Furthermore, since the propeller shaft is exposed to the outside of the vehicle and exposed to rainwater, etc., if a material with a different ionization tendency from the propeller shaft forming material is used as the balance weight forming material, electrolytic corrosion may occur between the two parts. There is a problem that crevice corrosion occurs.

The present invention was made to solve such problems, and when the propeller shaft body is made of a light alloy type, this invention can be used to adjust the rotational balance of the propeller shaft without increasing the volume of the balance weight. The object of the present invention is to provide a balance weight mounting structure for a light alloy propeller shaft that can facilitate welding of the balance weight and also prevent corrosion such as electrolytic corrosion between the propeller shaft body and the balance weight. It is something to do.

(Means for Solving the Problems) The balance weight mounting structure for a light alloy propeller shaft of the present invention has a light alloy propeller shaft body formed of the same material as the shaft body in a portion where balance adjustment is required. Welded a support pin, and with this support pin,
A balance weight made of a metal material with a higher specific gravity than a light alloy is engaged and supported, and when this balance weight is engaged and supported by this support pin, water does not accumulate between this balance weight and the propeller shaft body. This is characterized in that a predetermined gap is formed.

Here, the above-mentioned "material similar to the shaft body" refers not only to the same material as the material forming the propeller shaft body, but also to
This means a metal material that can be more easily welded to the propeller shaft body than steel.

(Function) According to the above configuration, a support pin made of the same material as the shaft body is welded to the light alloy propeller shaft body, and the balance weight attached via this support pin is welded to the light alloy propeller shaft body. Made in Japan.

In other words, since the balance weight is engaged with and supported by the shaft body using a support pin, there is no need to weld the balance weight directly to the propeller shaft body. This makes it possible to use metals with high specific gravity. This makes it possible to reduce the volume of the balance weight compared to a case where the balance weight is made of a light alloy material.

Furthermore, since the support pin is made of the same material as the shaft body, it is easy to weld the support pin to the shaft body. Furthermore, if the balance weight is made of a material different from the propeller shaft body, there is a risk of electrolytic corrosion occurring between these two parts since the propeller shaft is placed in a position exposed to rainwater, etc. According to the structure, these balance weights and the propeller shaft body are arranged at a predetermined interval to prevent water from accumulating, so there is no risk of water intervening between these two members for a long time, thereby preventing electrolytic corrosion etc. Can prevent corrosion from occurring.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a front view showing a propeller shaft to which a balance weight is attached using an embodiment of the present invention, and FIG. 1 is a sectional view taken along the line XX in FIG. According to FIG. 1, a balance weight 3 made of steel is disposed via a stud pin 2 made of aluminum at a necessary balance portion on the outer surface of an annular propeller shaft body 1 made of aluminum. As shown in FIG. 3, this balance weight 3 is formed in an arc shape along the outer surface of the propeller shaft body 1, and is made of steel having a high specific gravity to prevent the weight from dispersing. Further, stud pins 2 for supporting the balance weight 3 on the propeller shaft body 1 are fitted into both ends of the balance weight 3.

This stud pin 2 has a large diameter part 2a above it and a small diameter part 2b below it, and this large diameter part 2a and the part following it are embedded in a balance weight 3, and balanced with a suitable adhesive. It is glued to weight 3.

On the other hand, the height A of the small diameter portion 2b is set to, for example, about 1 mm, and the distance B from the end surface where the small diameter portion 2b is formed to the lower surface of the balance weight 3 is, for example, 1 mm.
It is formed to about several m1. To install the balance weight 3, the balance weight 3 fitted with the stud pin 2 is placed on a predetermined position on the propeller shaft body 1 and pressurized, and the contact part between the stud pin 2 and the propeller shaft body 1 is placed in a predetermined position. This is done by spot welding by applying a current of . By this spot welding, the small diameter portion 2b is welded to the wall surface of the shaft body 1. By this welding, the small diameter portion 2b of the stud pin 2 is in a collapsed state, and after the welding is completed, the balance weight 3 and the shaft body 1 are placed at a position with an interval substantially equal to the above-mentioned distance B. The propeller shaft is exposed to the outside from the vehicle body, and there is a risk that it will be constantly exposed to rainwater, etc. Therefore, as in this example, the propeller shaft body 1
When the balance weight 3 and the balance weight 3 are made of different materials, electrolytic corrosion may occur if water remains between the two members 1 and 3 for a long time. Therefore, in the above embodiment, a gap corresponding to the above distance B is provided between the two members 1.3 to prevent water from accumulating. In addition,
If a gap is formed in the bonded portion between the balance weight 3 and the stud pin 2, problems such as the above-mentioned electrolytic corrosion will occur, so the bonding should be done securely so that such a gap does not occur. Furthermore, it is desirable that the balance weight 3 be subjected to anti-rust treatment.

Note that the mounting structure according to the present invention is not limited to that of the above-mentioned embodiments; for example, the shape and material of the balance weight can be changed in various ways, and other high-grade materials such as lead can be used instead of steel. It is also possible to use specific gravity metal materials. Further, the engagement between the stud pin and the balance weight is not limited to only adhesive bonding as in the above embodiments, but it is also possible to use a mechanical pressure bonding method such as caulking. FIG. 5 shows an example in which the two members are engaged by caulking.

That is, as shown in FIG. 5, the cylindrical stud pin 2
Insert the end of c into the mold 5 and fix it, and fit the stud pin 2C into the fitting hole of the balance weight 4. In this state, press the stud pin 2C from the direction of arrow C to remove the balance weight 4. caulk. FIG. 6 shows the state in which the stud pin 2c is attached after this caulking process. In addition, as mentioned above, the stud pin 2C
If there is a gap between the balance weight 4 and the balance weight 4, problems such as electrolytic corrosion will occur, so it is necessary to securely caulk the balance weight 4 so that there is no gap.

Note that the material for forming the stud pin 2.2c is not limited to aluminum, and other metal materials that are easily welded to aluminum may also be used.

(Effects of the Invention) As described above, according to the balance weight mounting structure for a light alloy propeller shaft of the present invention, a balance weight made of a high specific gravity metal is attached via a support pin made of a material similar to that of the propeller shaft body. Since the weight is attached, welding becomes easy and the volume of the balance weight can be reduced.

Further, since a predetermined gap is provided between the propeller shaft body and the balance weight by the support pin to prevent water from accumulating, problems such as electrolytic corrosion do not occur.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a balance weight mounting structure according to an embodiment of the present invention, FIG. 2 is a front view showing the balance weight mounting structure shown in FIG. 1 together with a propeller shaft, and FIG. 3 is the same as that shown in FIG. 4 is a schematic diagram showing an enlarged view of the stud pin shown in FIG. 1, and FIGS. 5 and 6 are modified examples of the stud pin shown in FIG. 1. It is a schematic diagram for explanation. 1... Propeller shaft body 2.20... Stud pin (support pin) 3.4...
Balance weight X” Shishi↓

Claims (1)

[Claims] A support pin made of the same material as the propeller shaft body is welded to the balancing part of the light alloy propeller shaft body, and a balance weight made of a high specific gravity metal material is engaged and supported by this support pin. A balance weight mounting structure for a light alloy propeller shaft, characterized in that the balance weight is arranged at a predetermined distance from the surface of the propeller shaft body.