JPS647250B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a second spring plate for a stacked leaf spring device,
In particular, the present invention relates to a second spring plate for a stacked leaf spring device, which has a second winding portion along the centerline of the first spring plate and having a width narrower than the centerline.

Mainly in a stacked leaf spring device for suspending heavy vehicles such as trucks, if a breakage accident occurs near the center point 2 of spring 1 (see Figure 1), the stacked leaf spring device will separate from the vehicle. As a temporary measure to prevent this, a second winding portion 5 is provided at the end portion 4 of the second spring plate 3 in a curved manner along the center portion 2. This second volume part 5 includes 3/4 volume, 1/2 volume, 1/4 volume, etc. that surround approximately 3/4 circumference, 1/2 circumference, and 1/4 circumference of the eyeball part 2, respectively. ,
(The figure shows 3/4 volume) The width is formed narrower than the eyeball part so as to avoid interference with the bracket provided on the vehicle body side for connecting the eyeball part 2 to the vehicle.

When forming the second spring plate 3 as described above, conventionally, the width and thickness of the material ₆ are approximately constant. Over a length range L corresponding to the sum of the length L ₂ which is approximately equal to 1/2 of the diameter, a knob processing 7 in which both sides in the width direction are cut in parallel or a triangular knob processing 8 in which a triangular shape is cut is applied. I was doing it. Therefore, the cut-off portion resulted in material loss, which worsened the material yield.

Furthermore, in order to reduce the weight of the stacked leaf spring device, the total number of spring plates is reduced and the plate thickness is increased; however, in this case, the second winding portion 5 has the same weight as the material 6. Therefore, the outer diameter of the eyepiece portion 2 and the thickness of the second turn portion 5 increase, resulting in problems such as the need to increase the size of the bracket.

The present invention has been made under the above circumstances, and its object is to provide a stacked leaf spring that has a good material yield and that can avoid the occurrence of interference at the connecting portion even when the material thickness increases. An object of the present invention is to provide a second spring plate for a device.

Hereinafter, the present invention will be described with reference to an illustrated embodiment. In FIG. 2, a material 10 formed into a strip of a predetermined length from a suitable spring steel, for example, has a flat plate end 11 having a constant width and thickness. This plate end 11 has a predetermined length range L ₀
As shown in FIG. 3, both sides 12 in the width direction are compressed and both sides 13 in the thickness direction are bulged, and then rolled so that the thickness becomes thinner. As shown in FIG. 4, it is formed in a tapered shape with a substantially constant width and a thickness that decreases toward the distal end, so that the length L is longer than the above length range L ₀ . The plate end portion 11 thus formed is curved along the eyelet b of the first spring plate a to form the second winding portion 14, as shown in FIG. Therefore, the length range L ₀ is set in advance so that a desired developed length of the second turn 14 can be obtained.

Each process such as rolling and bending as described above may be performed either cold or hot, and whether it is performed depends on the material of the material 10, the degree of processing of the plate end 11, finished dimensions, etc. will be set accordingly.

The second spring plate formed as described above is subjected to other appropriate processing, heat treatment, surface treatment, etc. as necessary, and is then combined with the first spring plate a and each of the third and subsequent springs provided as necessary. It overlaps with the plate and is incorporated into the stacked plate spring device.

According to the above structure, since the width of the plate end portion 11 is narrowed by rolling, there is no need to cut off the material, and the length is increased by rolling so that the thickness decreases toward the tip. Therefore, the length of the material 10 can be shortened, and together with this, it is possible to contribute to improving the material yield and reducing the weight.

In other words, if we look at the edge of a plate whose width is 80 mm, thickness is 16 mm, and the desired length range L is 214 mm, its weight is 2.15 kg, but it is necessary to cut 7 mm on each side on both sides in the width direction. In the conventional method of dropping, approximately 0.376 kg of caustic wood is produced, but according to the present invention, this can be reduced to zero. Also, since the weight of the second winding portion 14 is approximately 1.376Kg, it is approximately 22.4Kg compared to the weight of approximately 1.774Kg when using the conventional method.
%, which is about a 36% reduction compared to the material weight of 2.15Kg.

In addition, since the second winding part 14 is formed in a tapered shape in which the thickness decreases toward the distal end, even if the outer diameter of the eyeball part b increases due to an increase in the plate thickness, the outer diameter of the second winding part 14 remains the same as the thickness. It does not increase as it would if it remained unchanged.
Therefore, even if the thickness of the spring plates is increased in order to reduce the weight by reducing the number of spring plates constituting the stacked leaf spring device, for example, it is not necessary to increase the size of the connecting bracket.

Moreover, the second winding portion 14 does not substantially contribute to the spring characteristics of the leaf spring, and the first spring leaf a
In the event of an accident such as breakage of the vehicle body, it is sufficient to temporarily maintain the posture of the vehicle body in a substantially normal state, so even if the vehicle body is formed into a tapered shape as described above, there will be no problem in practical use.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, the first volume center part b as shown in the figure
In addition, it can also be applied to the centerpiece of the lower volume, the Berlin-shaped centerpiece, etc. Further, the plate end portion 11 corresponding to the second turn portion 14 may be formed by rolling so that the width becomes narrower toward the tip (see FIGS. 6A and B), or the thickness may be approximately constant. It may be rolled and formed (see Fig. 7). In short,
Instead of separately performing the step of rolling so that the sub-side becomes narrower and the step of rolling so that the thickness becomes thinner, they may be performed almost simultaneously. In addition, various modifications and applications are possible within the scope of the gist of the present invention.

As described above, the end portion of the material plate corresponding to the second winding portion is formed by rolling to have a narrow width and a thin thickness. Spring plates can contribute to improved material yield and weight reduction when compared to conventional spring plates, and even if the outer diameter of the center part increases, the outer diameter of the second turn can be made smaller than when the thickness remains unchanged. Even if the weight of the leaf spring device is reduced by increasing the thickness and reducing the number, there is an effect that there is no need to change the vehicle body side connection structure to the eyeball portion.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional example, Figs. 2 to 5 show an embodiment of the present invention, Figs. 2 A and B are a top view and a side view of the end of the material plate, and Figs. 3 A and 5. B is a top view and a side view showing the state after rolling to reduce the width, FIGS. 4A and B are a top view and side view showing the state after rolling to reduce the thickness, and FIG.
FIG. 6 is a side view showing the state after molding of the number part, and FIGS. 6A and 6B and FIG. 7 are explanatory views showing modified examples. DESCRIPTION OF SYMBOLS 10...Material, 11...Plate end, 12...Both sides in the width direction, 13...Both sides in the thickness direction, 14...2nd winding portion, a...1st spring plate, b...eye portion.

Claims (1)

[Claims] 1. In a spring plate having a second winding part that is narrower in width than the eyelet part of the first spring plate, the end part of the material plate corresponding to the second winding part is rolled to be narrower and narrower than the eyelet part. A second spring plate for a stacked leaf spring device, characterized in that it is formed to have a thinner thickness.