JPS62127534A - Leaf - Google Patents

Abstract

PURPOSE:To alter characteristic frequency in a lead as well as to prevent the occurrence of resonance of a leaf to vibrations to be produced out of a gear or the like, by forming each convex part as a mass damper solidly in plural spots in a longitudinal direction of the lead at the time of rolling. CONSTITUTION:In this lead 2, each convex part as a mass damper is formed in a lower surface 2d of the leaf 2 at plural spots in both longitudinal directions of a clamping part 2u by a U-bolt 8 by means of rolling, and this leaf 2, as a long tapered leaf as a whole, is formed so as to increase its thickness gradually ranging from an eye part 2e to the central part in design. To constitute a laminated spring 3 with this leaf 2, another leaf 4 formed like the leaf 2 is superposed on the lower side, inserting a spacer of plastics or the like at need, whereby these leaves 2 and 4 are made contact with each other so that proper intermediate friction is securable, thus a damping characteristic of the laminated spring 3 is improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a spring, in particular, a mass damper for preventing resonance due to the meshing sound of a differential gear on a rear axle of a vehicle, which is integrally formed by rolling a spring plate. This invention relates to a spring whose natural frequency can be freely changed by rolling.

Prior Art Conventionally, according to Japanese Utility Model Application No. 59-133847, a leaf spring 1 as shown in FIG. 4 resonates with a frequency component around 40 Hz of vibration generated by engagement of a differential gear on a rear axle of a vehicle. Although differential noise was amplified and propagated into the vehicle interior, this structure can be prevented by integrally providing a mass damper at the center of the front and rear spans of the uppermost spring plate of the temporary spring. However, since the mass damper shown in the conventional example was formed in a rectangular shape protruding above the spring plate, it may be difficult to implement in actual manufacturing, and there is room for improvement. was there.

Purpose The present invention has been made in order to eliminate the drawbacks of the prior art described above, and its purpose is to cause a leaf spring to resonate with vibrations generated from a differential gear on the rear axle of a vehicle, causing the gear to By forming an integrated mass damper on the spring plate at the same time as the spring plate is rolled, the natural frequency of the spring plate can be adjusted freely depending on the method of rolling. The purpose is to make it possible to change the shape of the leaf spring, and thereby to more completely prevent the leaf spring from resonating with respect to the above-mentioned vibrations.

Another purpose is to facilitate the formation of such a mass damper and to improve mass productivity.

Structure In short, the present invention is characterized in that convex portions serving as mass dampers are integrally formed at a plurality of locations in the length direction by rolling.

The present invention will be explained below based on embodiments shown in the drawings. As shown in FIG. 1, the spring plate 2 according to the present invention has convex portions 2a as mass dampers at a plurality of locations in the longitudinal direction, for example, at the center of one left and right span of a portion 2u for tightening with U bolts. It is formed integrally by rolling. Further, this spring plate 2 is formed so that the plate thickness gradually increases from the center portion 2e toward the portion 2u when tightened with a U bolt so that the entire spring plate is basically formed as a long taper spring plate. . Therefore, unlike the conventional example, the convex portion 2a of the spring plate 2 according to the present invention is formed not on the upper surface 2c but on the lower surface 2d of the spring plate 2, and the convex portion 2a closer to the eyeball portion 2e is formed on the lower surface 2d of the spring plate 2. For tightening with bolts, use the convex part 2 that is closer to part 2u.
Its height is formed lower than that of a.

In order to construct a stacked leaf spring 3 as shown in FIG. 2 using such a spring plate 2 according to the present invention, another spring plate 4 having a convex portion 4a formed in the same manner as the spring plate 2 is required. Spring Ii 2
The upper end 4b of the spring plate 4 is brought into contact with the end 2b of the spring plate 2, and both spring plates 2 are stacked on top of each other as necessary.
A spacer 5 made of, for example, polycarbonate resin is interposed between the spring plates 2 and 4, and the spring plates 2 and 4 are brought into contact with each other in the middle of one span through the spacer 5, thereby achieving appropriate friction between the plates. Obtainable. Then, the axle 9 and the stacked leaf spring 3 can be fixed with the U bolt 8 via the pad 6.

Next, the rolling process of the spring plate 2 according to the present invention will be explained with reference to FIG. The rolling rolls 12 rotate in the direction of arrow C, respectively. In this case, the rolling roll 12 has, for example, two convex portions 1.
2a and two concave portions 12b are formed, and the other portions are comprised of a profile with a gradually increasing radius of curvature, a profile of concentric circles, etc. to give the spring plate 2 a long taper. Then, as described above, the re-rolling rolls 11 and 12 are rotated in the directions of arrows B and C, and the spring plate material 10 is
By supplying the convex portion 2a in the direction of arrow A, it is possible to roll the convex portion 2a as shown in FIG. Further, the number of convex portions 2a is not limited to two per span, and the number of convex portions 2a may be one or three or more as necessary.

Function The present invention is constructed as described above, and its function will be explained below. By using the spring plate 2 according to the present invention in a vehicle, the tightening of the spring plate with the U-bolt can be performed by the part 2.
Since a plurality of convex portions 2a are formed between u and the eyeball portion 2e, the partial mass of the spring plate changes at the convex portions, and the natural frequency of the spring plate 2 changes. This prevents the temporary spring from resonating with the vibrations generated by the differential gear (not shown) on the rear axle and amplifying the meshing vibrations of the gears, thereby making it possible to reduce the indoor noise of the vehicle. In addition, such a convex portion 2a can be formed at the same time as the rolling process, and its position is also determined by the rolling roll 1.
Since the shape of the spring plate 2 can be changed arbitrarily, it is extremely suitable for mass production, and the spring plate 2 can have an arbitrary natural frequency.

Furthermore, by using the spring plates 2 and 4 according to the present invention in the stacked plate spring 3 as shown in FIG. 2, a spacer 5 can be interposed between the spring plates 2 and 4, and the Since the convex portion 2a of the spring plate 2 is in contact with the spacer, and the spacer is in constant contact with the upper surface 4C of the spring plate 4, a large friction between the plates can be obtained, and the damping characteristics of the stacked leaf spring 3 can be improved. can be improved.

Further, as shown in FIG. 3, an intermediate spring plate 14 is interposed between the first spring plate 11 and the second spring plate 12 of the stacked leaf spring 13, and a plurality of asymmetrical spring plates are provided on both upper and lower surfaces of the intermediate spring plate. It is also possible to form a convex portion 14a as a mass damper. Also the fourth
As shown in the figure, the first spring plate 21 and the second spring plate of the stacked leaf spring 23 are
It is also possible to interpose an intermediate spring vi24 between the intermediate spring plate 22 and form a plurality of convex portions 24a as mass dampers symmetrically on both upper and lower surfaces of the intermediate spring plate. Note that the functions of these embodiments shown in FIGS. 3 and 4 are the same as those described above, and therefore explanations regarding the functions will be omitted.

Effects Since the present invention is configured and operates as described above, the temporary spring resonates with the amplitude generated from the differential gear of the rear axle of the vehicle, and the leaf spring amplifies the meshing vibration of the gears. Since the integral mass damper that prevents vibrations is formed on the spring plate at the same time as the spring plate is rolled, the natural frequency of the spring plate can be freely changed depending on the method of rolling. As a result,
The effect of being able to more completely prevent resonance of the leaf spring due to the above-mentioned vibration can be obtained. Further, the formation of such a mass damper can be facilitated, and there is an effect that mass productivity can be improved.

[Brief explanation of drawings]

1 to 5 relate to embodiments of the present invention, FIG. 1 is a side view of a spring plate, FIG. 2 is a side view of a stacked leaf spring using spring plates according to the present invention, and FIG. 3 is a side view of a spring plate according to the present invention. FIG. 4 is a side view of a stacked leaf spring in which convex portions are formed asymmetrically on both the upper and lower surfaces of the intermediate spring plate. FIG. FIG. 6 is a side view showing a process of forming a convex portion by rolling, and FIG. 6 is a side view of a conventional long taper spring plate. 2.4 is a spring plate, and 2a, 4a, 14a, and 24a are convex portions as mass dampers.

Claims (1)

[Claims] A spring plate characterized in that convex portions serving as mass dampers are integrally formed at multiple locations in the length direction by rolling.