JPH0829548B2 - Propeller shaft manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a propeller shaft applied to a traveling vehicle.

(Prior Art) An example of a conventional propeller shaft is shown in FIG. That is, the propeller shaft 10 has a universal joint yoke 11 and a spline joint yoke 12 at both ends thereof, and the main body portion of the propeller shaft 10 is made of a pipe material. The propeller shaft 10 transmits, for example, a driving force output from a transmission of an engine mounted on the front side of the vehicle body to a final speed reducer attached to a drive shaft on the rear side of the vehicle body. Since the propeller shaft 10 rotates at high speed while constantly receiving varying engine torque, it is prone to torsional vibrations and other vibrations.Because the inside is hollow, air inside the hollow part causes air column vibrations. Cause resonance with the propeller shaft 10, which causes vibrations of the propeller shaft 10 to be transmitted to the passenger compartment and generate muffled noise, or to the transmission and final reduction gear to generate gear noise, which is a so-called vibration transmission sound. There's a problem. Therefore, in order to solve this problem, in the hollow part of the hollow propeller shaft,
A countermeasure is known in which a vibration absorber that damps the vibration of the propeller shaft is inserted. That is, this vibration absorber is made of paper, vinyl chloride, rubber, hard urethane, or the like, and the outer diameter of each is fitted into the inner diameter of the hollow portion, which is solid (see FIG. 5 (a)). Reference numeral 10a), a hollow one (reference numeral 10b in FIG. 9B), and a hollow one with a slit provided in the longitudinal direction (reference numeral 10c in FIG. 10C).

(Problems to be Solved by the Invention) However, even if the vibration absorbers 10a, 10b, and 10c as described above are inserted into the hollow portion of the propeller shaft, there is a problem that a sufficient effect of reducing the vibration transmission sound cannot be obtained. . The reason is that it is not yet clear what kind of material and shape of the vibration absorber is suitable for the effect of reducing the vibration transmission sound.
In many cases, the characteristics of the selected vibration absorber are inappropriate. In addition, it is also possible that the characteristics of the vibration absorber are not uniform in the longitudinal direction because the production method has not been established.Furthermore, the method of inserting the vibration absorber into the hollow part of the propeller shaft is that the vibration is absorbed by long-term operation. There is also a fear that the contact between the body and the propeller shaft becomes incomplete and rather the vibration and tapping noise are induced.

(Means for Solving the Problems) Therefore, in order to solve the above problems in the conventional method, the present invention is a semi-hard material having a density of 0.2 to 0.4 g / cm ^{3 in} the hollow portion of the propeller shaft body made of a pipe. This is a method for manufacturing a prom propeller shaft, which comprises filling urethane foam and then fixing yokes to both ends thereof.

(Operation) A hollow propeller shaft main body is filled with semi-rigid urethane foam having a density of 0.2 to 0.4 g / cm ³ , and then this is sealed.

(Example) Hereinafter, the present invention will be described in detail based on an illustrated example.

FIG. 1 shows a cross section of a propeller shaft 1 obtained by carrying out the present invention, in which a front yoke 2 and a rear yoke 3 are fitted and welded at both ends to a hollow portion of a pipe 4 as a propeller shaft body. Hard urethane foam 5 is filled. On the surface of the pipe near the rear yoke 3, a mass balance 6 is attached for dynamic balance.

First, the semi-rigid urethane foam 5 as a filler will be described. According to the Ashida method, which is one of the classification methods for plastic foams, when 20% compressive deformation is applied, the material that breaks is hard foam, which does not break and has a 25% compressive elastic modulus of 100 g / cm ³ or more. Is classified as semi-rigid foam. The inventor prepared a rigid urethane foam and a semi-rigid urethane foam having different densities, and tested the vibration characteristics (first bending level) of the propeller shaft. The result is shown in FIG. That is, in the figure, the tendency that the vibration level decreases as the density increases is the same for these two materials, but the loss coefficient of the rigid urethane foam shows a low value with almost no effect on the density. On the other hand, in the case of semi-rigid polyurethane foam, it tends to increase in proportion to the density. Therefore, based on such experimental results, it can be said that the most suitable material for the hollow portion filler of the propeller shaft is a semi-rigid urethane foam having a density of 0.2 to 0.4 g / cm ³ . Table 1 shows other characteristic values of the semi-rigid urethane foam. The compressive strength in the table is the value at 50%.

Next, a method for manufacturing such a propeller shaft will be described. In the process diagram shown in FIG. 2, first, an isocyanate, a polyol, a foaming agent, a catalyst and others as raw materials are weighed, put into a mixing device and mixed by hand mix. On the other hand, as shown in FIG. 3, the pipe 4 of the propeller shaft is fixed with an inclination of about 15 ° with respect to the horizontal plane H in order to make the density distribution in the longitudinal direction uniform, and the lower opening is It is sealed by a lower lid 13 and the upper end is open. Next, the mixed liquid is injected from the upper end opening of the inclined pipe 4, and when the mixture is injected up to the vicinity of the upper end opening, the pipe is erected and foamed. After this, the lid 14 is used to seal the upper end opening.
You can put 14 on. In this case, in order to enhance the adhesiveness between the filler and the inner peripheral surface of the pipe, it is necessary to mix an adhesive agent in the mixed solution or apply an adhesive agent to the inner surface of the pipe prior to injecting the mixed solution. , An adhesive strength of about 0.2 to 0.5 kg / cm ² can be obtained. After the mixed liquid inside the pipe 4 foamed and solidified sufficiently, the lids 13 and 14 were removed from both ends, and the front yoke 11 and the rear yoke 12 (see FIG. 1) were fitted in place of them, and the pipe ends Weld to each part and fix.
Next, the front yoke 11 and the rear yoke 12 at both ends of the pipe 4
The drive unit and the driven unit are connected to each to measure the rotation,
If necessary, install the mass balance and then install it on the actual vehicle.

The propeller shaft 1 configured as described above is used for transmitting a driving force output from, for example, a transmission arranged in front of a vehicle body to a final reduction gear mounted on a drive shaft at the rear of the vehicle body. The generated torsional vibration and other vibrations are damped by the filling material 5 in the hollow portion of the pipe 4 to reduce the generation of vibration transmission sound.

(Effect of the invention) As apparent from the above description, the present invention has a good vibration absorbing property in the longitudinal direction of the pipe by inclining the pipe at about 15 ° and injecting the semi-rigid urethane foam raw material liquid mixed by hand mix. A density of 0.2 to 0.4 g / cm ³ can be evenly distributed, the effect of reducing vibration transmission noise can be improved, and the balance is not lost during high speed rotation. In addition, since the filling material is light, the moment of inertia around the axis of the propeller shaft is not significantly increased, and the use of an adhesive does not cause a relative deviation between the filling material and the pipe for a long period of time. Play.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a propeller shaft obtained by carrying out the present invention, FIG. 2 is a process drawing showing a manufacturing process of an embodiment of the present invention, and FIG. 3 is tilted at the time of injecting a filler. 4 is a sectional view showing a pipe, FIG. 4 and FIG. 5 are partial sectional external perspective views and sectional views showing an example of a conventional propeller shaft,
FIG. 6 is a diagram showing a graph comparing the properties of the semi-rigid urethane foam and the rigid urethane foam with respect to vibration absorption. 1 ... Propeller shaft, 2,3 ... Yoke, 4 ... Pipe, 5 ... Filling material.

Claims (1)

[Claims] 1. A propeller shaft main body made of a pipe has one opening closed and 0.2 to 0.4 g /
A propeller shaft characterized in that a semi-rigid urethane foam raw material having a density of cm ³ is filled, this is foamed and solidified, then the other opening is closed, and yokes are fixed to both ends of the propeller shaft body. Manufacturing method.