JPH02217632A - Laminated leaf-spring - Google Patents

Abstract

PURPOSE:To enhance riding comfortableness and damp the vibration of a load- carrying platform caused by impact so as to prevent loading from being broken by forming protrusions corresponding to respective recessed and projecting portions in which spacers abutting to the sliding shuckle side of a top plate are arranged, and causing the protrusions to abut to under plates. CONSTITUTION:Until a spring plate slides on between respective contacts A of a spacer 6 and a sliding shuckle 5, slippage will not occur between spring plates of the laminated leaf-spring by friction muP generated between the contacts A when the top plate 1 is bent, whereas by friction muP generated between respective contacts B of the top plate 1 and an under plate 3 until a spring plate slides on between the contacts B; then the top plate 1 is deformed so that the leaf-spring is bent. When loads are further increased and bending increased accordingly, a sliding force between the contacts generated by variation of leaf-spring spans overcomes the friction muP and muP so that slippage parts to occur. When loads are decreased distortion energy of bending moment acting on the top plate 1 is released and then the plates start to return from their bent state to original state while slippage does not occur between the leaf springs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stacked leaf spring having one end configured in the form of a sliding shackle.

[Conventional technology]

Conventionally, in a stacked leaf spring constituting a suspension for an L-rack, a main plate 1 of a sliding structure is used, as shown in FIG. It has been known. The load-deflection characteristic of such a stacked leaf spring, that is, the spring constant, is the 11th
It is as shown in the figure.

Also, for example, in Japanese Patent Application Laid-Open No. 56-141433,
A stacked leaf spring device is disclosed in which the spring constant changes discontinuously at a predetermined load value. The stacked leaf spring device includes a main leaf spring and an auxiliary leaf spring whose only end portion of the drawing plate can freely move toward and away from the main leaf spring, and the main leaf spring only contacts the end of the drawing plate of the auxiliary leaf spring in a load region of a predetermined value or more. Further, the auxiliary leaf spring has a tapered portion whose thickness gradually decreases toward the end of the plate.

[Problem to be solved by the invention]

However, when we calculate the diagonal spring constant, the so-called dynamic spring constant, and the amplitude dependence of frixigin based on the load-deflection characteristics of a sliding shackle type stacked leaf spring as shown in FIG. This is shown by the solid line in Figure 13. That is, it can be seen that the diagonal spring constant is high in a small amplitude range, and as the amplitude increases, the diagonal spring constant decreases and approaches the static spring constant. By the way, as for vehicle suspension,
A spring is desired that has a low spring constant at small amplitudes, providing a soft ride, and a high spring constant at large amplitudes, providing a stable and rigid feel. Therefore, the conventional stacked leaf spring is
It has completely opposite characteristics and can be said to be disadvantageous in terms of performance.

In conventional stacked leaf springs, as a means to obtain a soft ride, in order to keep the diagonal spring constant low at small amplitudes, the number of springs that make up the stacked leaf spring is reduced (or by adding low friction to the end of the leaf). It has also been done to reduce the friction by inserting a material, but when a stacked leaf spring is constructed in this way, it becomes as shown by the dotted line in FIGS. 12 and 13.

That is, the friction at large amplitudes is reduced and the diagonal spring constant is reduced, resulting in a suspension that lacks a sense of rigidity and has poor stability.

In addition, the stacked leaf spring device disclosed in the above-mentioned Japanese Patent Application Laid-open No. 56-141433 has a tapered portion in which the thickness force q gradually decreases in the direction of the public information section in the auxiliary leaf spring as in the above configuration. Not only does it have discontinuous spring characteristics, but the stress distribution in the longitudinal direction is evened out, making effective use of materials and reducing weight.

The purpose of this invention is to solve the above problems,
In a stacked leaf spring consisting of a main plate with one end configured in the form of a sliding shackle and several child plates, the shape of the main plate is configured so that the sliding shackle can take advantage of the friction that acts on the parent unit, and the amplitude is small. It is configured to suppress the friction in
In addition to improving ride comfort, 13% of the cargo space! To provide a stacked leaf spring capable of alleviating vibration and preventing damage to cargo.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, this invention consists of a main plate whose negative end abuts the sliding shackle and a daughter plate fixed to the main plate with bolts, and a recess in which a spacer is disposed on the sliding shackle side of the main plate, and a recess corresponding to the recess. The present invention relates to a stacked leaf spring in which a protrusion is formed on the daughter plate side, the spacer and the sliding shackle are in contact with each other, and the protrusion and the daughter plate are in contact with each other.

Alternatively, in this invention, -4 is made up of a master unit that comes into contact with a sliding shackle and a slave plate fixed to the master machine with bolts; The present invention relates to a stacked leaf spring in which the spring plate shape of the parent plate is formed into a downwardly inclined concave curved surface, and the daughter plate is formed into a downwardly inclined concave curved surface so as to correspond to the concave curved surface.

[Effect]

The stacked leaf spring according to the present invention is constructed as described above and operates as follows. That is, this stacked leaf spring is
Bringing the sliding shackle into contact with the spacer fixed to the recess on the sliding shackle side of the parent plate,
Since the protrusion protruding toward the daughter plate side is brought into contact with the daughter plate, when the spring plate bends due to a change in load, the spring plate bends to the parent plate due to the friction generated between the contact points of the spacer and the sliding shackle. A moment is generated, and the parent plate is subjected to a bending moment due to frixidine generated between the contact points of the protrusion and the daughter plate.

Alternatively, in this stacked leaf spring, the shape of the main plate on the center side from each contact point between the main plate, the sliding shackle, and the daughter plate is formed into a downwardly inclined concave curved surface, so that the same friction and bending moment as described above can be generated. Spring characteristics can be obtained.

〔Example〕

Hereinafter, one embodiment of a stacked leaf spring according to the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram showing an embodiment of a stacked leaf spring according to the present invention, Fig. 2 is an explanatory diagram showing the main part of Fig. 1, and Fig. 3 shows a part of the main plate of Fig. 1. FIG.

FIG. 1 shows a stacked leaf spring according to the invention. This stacked leaf spring consists of a main plate 1 which has an eye 2 at one end and contacts a sliding shackle 5 at the other end, and a plurality of daughter plates 3 (two in the figure), which are stacked over the entire length of the spring plates. , a center bolt 4 and a clip placed at a predetermined position in the center of each spring machine (not shown)
Each spring plate is fixed by. This stacked leaf spring is configured as a taber leaf spring in which a parent plate 1 and a daughter plate 3 are formed in a tabular shape.

Generally, in a stacked leaf spring, each spring leaf is formed to obtain a predetermined spring constant, each has its own deflection curve, and deforms in response to external force. It shows the load-deflection characteristics as shown.

In the stacked leaf spring according to the present invention, the end of the main plate 1 that comes into contact with the sliding shackle 5 has a recess with a semicircular cross section on the sliding shackle side surface of the main plate 1, as shown in FIG. 2 or 3. 7 is formed in the width direction of the spring plate, and a protrusion 8 is formed in the width direction of the spring plate on the surface of the main plate 1 on the child plate 3 side corresponding to the recess 7 and protruding toward the child plate 3 side. ing.

A spacer 6 is fixed to a recess 7 formed in the main plate 1. Due to the above structure of the main plate 1, the spacer 6 fixed to the recess 7 of the main plate 1 and the sliding shackle 5 are placed in contact with each other, and the protrusion 8 formed on the main plate 1
is arranged in contact with the upper surface of the daughter plate 3 located at the top.

Regarding the stacked leaf spring according to the present invention, when the spring plate is bent due to a change in load, a bending moment is generated due to frixigin generated between the contact point of the sliding shackle 5 and the spacer 6 housed in the recess 7 having a semicircular cross section of the parent plate 1. occurs on the main board 1.

That is, as shown in FIG.
When the radius of the protrusion 8 formed corresponding to the formation of is R, the friction generated between the contact point A of the spacer 6 and the sliding shackle 5 is μP1, and therefore the bending moment generated on the main plate 1 is , R×μP1. Furthermore, the protrusion 8 formed on the main plate 1 is in contact with the uppermost surface of the daughter board 3, and the main board 1 is also subjected to friction at the contact point B with the daughter board 3. That is, if the load applied to the daughter plate 3 is Pt and the coefficient of friction is μ, the friction generated between the contact point B between the mother plate 1 and the daughter plate 3 is μP2, and therefore, the bending moment that the mother plate 1 receives is: R×
There will be one μP.

Regarding the stacked leaf spring according to the present invention, the friction μP1 and μPL as described above and the bending moment)R
Since XμP and R×μPt are generated, the following effects occur. That is, the bending moment acting on the main plate l is
When the vAAl1 spring plate is bent, the friction μP that occurs between the contact point A of the spacer 6 and the sliding shackle 5 causes a Due to Frixigin μP2 occurring between contact points B, no slipping occurs between the spring plates of the stacked leaf spring until the spring plates begin to slide between contact points B.
The spring plate bends due to the deformation of the main plate 1.Furthermore, as the load applied to the spring plate increases and the deflection of the spring plate increases, the sliding force between each contact point due to the change in the spring plate span increases due to the friction μ.
P1 and friction μP2 are overcome and slipping begins to occur.Next, when the load on the spring plate begins to decrease, the strain energy corresponding to the bending moment acting on the parent plate l is released, causing the parent plate to Since it acts in the direction of restoring the deformation of the plate l, the deflection begins to return to its original state without slipping between the spring plates. The above phenomena are all effects in the case of a small amplitude range, but when the amplitude is large, after passing through the effects of the bending moments R×μP1 and R×μP2, a sliding phenomenon between each spring plate occurs. is similar to that of a conventional stacked leaf spring.

From the above, the overlapped spring according to the present invention has a load-deflection characteristic that occurs in the small amplitude region before the spring plates begin to slip, and a load-deflection characteristic that occurs in the medium-width region to large amplitude region where the spring plates start to slip. The observed load-deflection characteristics are shown in FIG. That is, in the load-deflection characteristics, the transition portion, that is, the slope of the curve B-C, can obtain smooth characteristics.
Further, the size of the frixillon, that is, the size of points A to C can be configured in the same manner as in the conventional case.

As a result of the above, for the stacked leaf spring according to the present invention, the amplitude dependence of the diagonal spring constant becomes as shown in Fig. 8, and the amplitude dependence of Frixilon becomes as shown in Fig. 9, which is ideal. characteristics can be obtained. That is,
As shown in the relationship between amplitude and friction in Figure 9, since the change in span is small in the small amplitude region, static friction becomes dominant until slippage occurs, and a characteristic with a steep rising slope can be obtained. . Due to the friction-amplitude characteristics shown in FIG. 9, the diagonal spring constant-amplitude characteristics become as shown in FIG.

When looking at the above characteristics in terms of load-deflection characteristics, as shown in FIG. 7, the load transfer portion draws a smooth hysteresis curve.

4, 5 and 6 show different structures of the parent plate 1 in the stacked leaf spring according to the invention.

In the embodiment shown in FIG. 4, the spacer 6 accommodated in the recess 7 having a semicircular cross section formed in the main plate 1 is prevented from falling off or shifting from the main plate 1. Therefore, the spacer 6 is fixed to the main plate 1 by welding 9. Similarly, in another embodiment shown in FIG.
Regarding the spacer 6 accommodated in the recess 7 having a semicircular cross section formed in the main plate 1, in order to prevent the spacer 6 from falling off or shifting from the main plate 1, the spacer 6 is
is fixed to the main plate l with bolts 10. In addition,
In the figure, the symbol R indicates the radius of the protrusion 8 formed in correspondence with the formation of the recess 7 having a semicircular cross section in the parent plate l.

Alternatively, in yet another embodiment of the stacked leaf spring according to the present invention shown in FIG. This stacked leaf spring is configured to apply a bending moment due to friction to the contact portions of side main board 1
The spring plate shape is formed into a downwardly inclined concave curved surface 12,
The daughter plate 3 is formed with a downwardly inclined concave curved surface 13 so as to correspond to the concave curved surface 12.

Therefore, a step H is formed in the spring plate eye of the main plate 1 inward from the contact points A and B by the concave curved surface 12 extending downward from the surface connecting the contact point between the central part 11 of the main plate 1 and the sliding shackle. Become so. The size of this step H is approximately the same as the radius R in each of the above embodiments.

In the stacked leaf spring according to the present invention, by configuring the main plate 1 as described above, similar to the above, when the spring plate is bent due to a change in load, a phenomenon occurs between the contact point between the main plate 1 and the sliding shackle 5. A bending moment is generated in the main plate 1 due to the friction caused by the bending. That is, if the load applied to the main plate 1 is Pl, the coefficient of friction is μ, and the level difference of the main plate 1 is H, then the friction generated between the contact point A of the main plate 1 and the sliding shackle 5 is μP1, and the friction coefficient of the main plate l is The bending moment generated is H×μP+.

In addition, the lower surface of the main plate 1 is in contact with the uppermost surface of the child plate 3, and the main plate 1
Also at the point of contact B with the daughter plate 3, the spring receives friction in the same way as the stacked leaf spring of the above embodiment.

That is, if the load applied to the daughter plate 3 is P and the coefficient of friction is μ, the friction generated between the contact points of the parent plate 1 and daughter plate 3 is μP2, and therefore, the bending moment that the parent plate 1 receives is HX μP , becomes.

〔Effect of the invention〕

The stacked leaf spring according to the present invention is constructed as described above, and has the following effects. That is, this stacked leaf spring consists of a main plate whose one end abuts the sliding shackle and a daughter plate fixed to the main plate with bolts, and a recess in which a spacer is arranged on the sliding shackle side of the tU plate and a recess in the recess. Correspondingly, a protrusion is formed on the daughter plate side, and the spacer and the sliding shackle are brought into contact with each other, and the protrusion and the daughter plate are brought into contact with each other, so that the spring plate flexes as the load increases. When mounting, a bending moment is generated in the main plate due to the friction generated between the contact points of the spacer and the sliding shackle, and furthermore, the friction generated between the contact points of the protrusion and the daughter plate causes the main plate to bend. subjected to bending moment. Therefore,
In the small amplitude region where the span change is small, the friction is suppressed and becomes small, and in the large amplitude region where the span change is large, it is possible to obtain characteristics dominated by the normal sliding friction between the plates, and the friction is reduced compared to the conventional stacked plate. Similar to springs, sufficient size can be obtained.

Therefore, by applying the laminated leaf spring according to the present invention to a vehicle, it is possible to obtain ride comfort characteristics, especially ideal frixidine characteristics in a small amplitude region, so that it can be used with a relatively small load. For the front axle suspension, which requires a low spring constant and large spring deflection, and for the rear axle suspension, which can handle large loads and large deflections and has a high spring constant, it is possible to soften vibrations in the small amplitude range. Not only does it improve the riding comfort of the vehicle, but it can also have great effects, such as preventing damage to cargo due to the mitigation of vibrations in the cargo platform.

Alternatively, this stacked leaf spring is composed of a parent plate whose one end abuts the sliding shackle and a daughter plate fixed to the parent plate with bolts, and the center side of each contact point between the parent plate, the sliding shackle, and the daughter plate. The spring plate shape of the parent plate is formed into a downwardly inclined concave curved surface, and the child plate is formed into a downwardly inclined concave curved surface to correspond to the concave curved surface, so that the same spring characteristics as above are obtained. In the same way as described above, it is possible to achieve ride comfort characteristics and the effect of preventing damage to cargo due to mitigation of impact vibration of the cargo platform.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of a stacked leaf spring according to the present invention, Fig. 2 is an explanatory diagram showing the main part of Fig. 1, and Fig. 3 is a perspective view showing a part of the main plate of Fig. 1. 4 is an explanatory diagram showing an example of the main plate in the laminated leaf spring according to the present invention, FIG. 5 is an explanatory diagram showing another example of the main plate in the laminated temporary spring according to the present invention, and FIG. Fig. 7 is a graph showing the load-deflection characteristics of the laminated leaf spring according to the present invention, and Fig. 8 shows the amplitude and diagonal line of the laminated leaf spring according to the present invention. 9 is a graph showing the relationship between the amplitude and friction of the stacked leaf spring according to the present invention, FIG. 10 is a schematic diagram showing an example of a conventional stacked leaf spring, and FIG. 11 is a graph showing the relationship between the spring constant and the spring constant. Graph showing the load-deflection characteristics of a conventional stacked leaf spring, No. 12
The figure is a graph showing the relationship between the amplitude and the diagonal spring constant of a conventional stacked leaf spring, and FIG. 13 is a graph showing the relationship between the amplitude and friction of a conventional stacked leaf spring. 1--Main board, 2--Eyeball, 3--Child board, 5 Sliding shaft, 6--Spacer, 7
- recessed portion, 8-- one protruding portion, 12-- concave curved surface. Figure 2 Figure 3 Applicant IsuV° Jidosha Co., Ltd. Agent Patent Attorney O Naka - So Figure Figure Figure Figure Amplitude - Figure Figure Figure Amplitude -

Claims (2)

[Claims] (1) Consisting of a parent plate whose one end abuts the sliding shackle and a daughter plate fixed to the parent plate with bolts, a recess in which a spacer is arranged on the sliding shackle side of the parent plate, and a daughter plate corresponding to the recess. A stacked leaf spring having a protrusion formed on a side thereof, the spacer and the sliding shackle being in contact with each other, and the protrusion and the daughter plate being in contact with each other. (2) Consisting of a parent plate whose one end abuts the sliding shackle and a daughter plate fixed to the parent plate with bolts, the parent plate is located on the center side of each contact point between the parent plate, the sliding shackle, and the daughter plate. A stacked leaf spring in which the spring plate shape is formed into a downwardly inclined concave curved surface, and the daughter plate is formed into a downwardly inclined concave curved surface so as to correspond to the concave curved surface.