JP2019043163A - Traverse-mounted leaf spring structure - Google Patents

Abstract

To provide a traverse-mounted leaf spring structure which can prevent or avoid that an upper-stage side leaf spring pushes and expands a rubber cap, and thereby generates cracks at the rubber cap.SOLUTION: A traverse-mounted leaf spring structure comprises: a plurality of leaf springs 3, 4 which are arranged while being bridged between left and right lower arms 10 of an independent suspension device 1, arranged while being vertically overlapped on each other, and formed into tapered shapes at end parts; and a rubber cap 13 for bundling the end parts of the leaf springs 3, 4. The upper-stage leaf spring 4 is formed shorter than the lower-stage leaf spring 3, and arranged so as to make an inclined part 15 separate from the rubber cap 13 to the inside of a vehicle width direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a transverse leaf spring structure used in an independent suspension system.

  Some independent suspension systems use transversely placed leaf springs. Such an independent suspension device slidably mounts the end of a leaf spring extending in the vehicle width direction on the left and right lower arms. As a result, the left and right lower arms are biased downward by the horizontal leaf spring. The leaf spring is formed in an arched shape and is stacked two on top of the other. In addition, these leaf springs are bundled with rubber caps at both ends. The rubber cap is formed in a tubular shape having a substantially rectangular cross section. In addition, a reinforcing member having a U-shaped cross section is embedded in the rubber cap.

  Further, the lower arm is formed in a triangular shape in plan view so as to avoid interference with the wheel. Therefore, the tips of the rubber cap and the leaf spring are tapered so as to follow the shape of the tip of the lower arm, and are engaged with the tip of the lower arm.

JP-A-8-318721 JP, 2015-85894, A JP, 2016-223602, A

  By the way, the leaf springs stacked vertically are formed to have the same length and the same shape. Also, the rubber cap is in contact with the front and rear edges of each leaf spring. The leaf spring absorbs the upward load while being deformed when an upward load is applied to the end. At this time, the leaf spring on the upper stage side is slid outward in the vehicle width direction with respect to the leaf spring on the lower stage side.

  For this reason, when the leaf spring on the upper side slides outward with respect to the leaf spring on the lower side in the vehicle width direction, the leaf spring on the upper side pushes the rubber cap at the inclined portion of the tapered shape and spreads. There was a possibility that it could occur.

  Accordingly, the present invention has been made in view of such circumstances, and an object thereof is to provide a horizontally placed leaf spring structure capable of preventing or suppressing that the leaf spring on the upper side pushes and expands the rubber cap to cause the rubber cap to crack. It is.

According to one aspect of the invention,
A plurality of leaf springs provided so as to extend between the lower arms of the left and right independent suspension devices and disposed one on top of the other with tapered end portions;
And a rubber cap for bundling the ends of these leaf springs,
The leaf spring on the upper side is formed to be shorter than the leaf spring on the lower side, and the inclined portion of the end portion is arranged to be spaced apart inward in the vehicle width direction from the rubber cap. A laterally placed leaf spring structure is provided.

  Preferably, when the lower arm is pivoted to the upper limit position, the inclined portion of the leaf spring on the upper side is formed so as not to project outward in the vehicle width direction from the inclined portion of the leaf spring on the lower side. Good.

Preferably, an end front edge of the leaf spring is formed with a straight portion linearly extending in the vehicle width direction,
The inclined portion is formed at an end rear edge of the leaf spring,
The inclined portion is inclined forward as it goes outward in the vehicle width direction,
The rubber cap is formed in a tubular shape having a rectangular cross section, and a front inner surface is formed in a planar shape along the straight portion of the lower leaf spring, and a rear inner surface is in the lower leaf spring. It is good to form in the planar shape which follows the said inclination part.

  According to the present invention, it is possible to prevent or suppress that the leaf spring on the upper side pushes and expands the rubber cap to cause the rubber cap to crack.

It is the rear view which looked at the independent suspension system where horizontal installation leaf spring structure concerning this embodiment is used from the vehicles back. It is a principal part expanded sectional view of a horizontally placed leaf spring. It is the top view which looked at the edge part of the horizontal placement leaf spring from the upper part. It is a principal part expanded sectional view of FIG. FIG. 5 is a cross-sectional view taken along line AA of FIG. 4; It is the rear view which looked at the leaf spring which deform | transforms from back. It is a principal part expanded sectional view of the horizontal placement leaf spring which shows other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, each direction of front and rear, right and left upper and lower sides in embodiment mentioned later shall mean each direction of a vehicle.

  FIG. 1 is a rear view of an independent suspension device 1 in which a laterally placed leaf spring structure according to an embodiment of the present invention is used, viewed from the rear. The independent suspension system 1 in FIG. 1 suspends a front wheel 2 which is a steering wheel. FIG. 2 is an enlarged sectional view of the left end portions of the leaf springs 3 and 4 shown in FIG. For convenience of explanation, the vehicle 5 provided with the independent suspension device 1 is shown with only the main parts omitted.

  As shown in FIG. 1, the vehicle 5 is, for example, a large vehicle such as a truck. The vehicle 5 includes a frame 6, an independent suspension system 1 supported by the frame 6, and a front wheel 2 suspended by the independent suspension system 1.

  The frame 6 includes a ladder frame 7 and a support frame 8 provided on the ladder frame 7 for supporting the independent suspension device 1. The ladder frame 7 is formed by bridging a plurality of cross members 7 a between a pair of parallel side members (not shown). The support frame 8 includes a vertical frame portion 8a provided on the ladder frame 7 and extending in the vertical direction, and a horizontal frame portion 8b extending outward in the vehicle width direction from the upper end of the vertical frame portion 8a.

  The independent suspension system 1 is configured of a double wishbone type independent suspension system. The independent suspension device 1 is provided rotatably on an upper arm 9 rotatably provided on an upper portion of the vertical frame portion 8a in the front and rear direction and on an axial extending in the front and rear direction on the lower portion of the vertical frame portion 8a. Between the lower arm 10, the knuckle 11 provided between the upper arm 9 and the lower arm 10 and rotatably supporting the front wheel 2, the shock absorber 12 provided between the lower arm 10 and the lateral frame portion 8b, and the left and right lower arms 10 It is provided with two leaf springs 3 and 4 which are provided so as to be bridged and arranged in layers one above the other, and a rubber cap 13 (see FIG. 2) for bundling the end portions of these leaf springs 3 and 4.

  The lower arm 10, the upper arm 9, and the knuckle 11 are parts constituting a parallel link, and support the front wheel 2 so as to ascend and descend while maintaining the substantially same posture. As shown in FIG. 2, on the upper surface 10a of the lower arm 10, a guide groove 10b for slidably guiding a rubber cap 13 described later in the vehicle width direction is formed. Further, as shown in FIGS. 3 and 4, lower arm 10 and upper arm 9 are formed in a triangular shape in plan view so as to avoid interference with front wheel 2.

  The lower end side leaf spring (hereinafter, lower end leaf spring) 3 is formed in a tapered shape at both ends so as to match the tip shape of the lower arm 10. Specifically, the lower leaf spring 3 is formed at the front end of the left and right ends and extends straight along the vehicle width direction, and at the rear end of the left and right ends outward in the vehicle width direction. And an inclined portion 15 which is inclined forward as it goes.

  The upper-stage leaf spring (hereinafter, upper-stage leaf spring) 4 is formed shorter than the lower-stage leaf spring 3, and both end portions are formed in the same shape as the lower-stage leaf spring 3. That is, at both end portions of the upper-stage leaf spring 4, linear portions 16 and inclined portions 17 having the same shape as the lower-stage leaf spring 3 are formed. Further, the upper stage leaf spring 4 is disposed so that both ends thereof are displaced inward in the vehicle width direction by the same length (displacement amount L) from both ends of the lower stage leaf spring 3 when the vehicle is stopped. Further, the inclined portion 17 of the upper stage leaf spring 4 is disposed inward in the vehicle width direction by a displacement amount L from the inclined portion 15 of the lower stage leaf spring 3. As a result, the inclined portion 17 of the upper leaf spring 4 is separated inward in the vehicle width direction from the rear inner surface 13b of the rubber cap 13 described later by the displacement amount L. As shown in FIG. 6, when the lower arm 10 is rotated to the upper limit position, the upper leaf spring 4 is shifted from the lower leaf spring 3 when the lower arm 10 is rotated to the upper limit position. The length is set so as not to protrude outward in the vehicle width direction.

  As shown in FIGS. 2 and 5, a sliding member 18 is interposed between the end of the upper leaf spring 4 and the lower leaf spring 3. The sliding member 18 is formed of a lubricating resin. Further, the sliding member 18 is formed with a convex portion 20 to be fitted in the locking hole 19 formed in the upper stage leaf spring 4. Thus, when the end of the upper leaf spring 4 slides on the lower leaf spring 3, the sliding member 18 slides with the upper leaf spring 4.

  The upper leaf spring 4 and the lower leaf spring 3 are engaged with the cross member 7a at the center in the vehicle width direction.

  The rubber cap 13 is formed in a tubular shape having a rectangular cross section so as to surround the end outer periphery of the lower leaf spring 3. Further, as shown in FIG. 4, the rubber cap 13 is formed in a generally tapered shape in plan view so as to follow the end shape of the lower leaf spring 3. The rubber cap 13 has a front inner surface 13 a formed in a planar shape along the straight portion 14 of the lower leaf spring 3, and a rear inner surface 13 b formed in a planar shape along the inclined portion 15 of the lower leaf spring 3. Further, the rubber cap 13 includes a rubber portion 21 formed in a tubular shape having a rectangular cross section, and a reinforcing member 22 having a U-shaped cross section and embedded in the rubber portion 21. The reinforcing member 22 is formed by bending a metal plate. Movement of the rubber cap 13 outward in the vehicle width direction is restricted by the guide groove 10 b of the rubber cap 13, and movement inward in the vehicle width direction is restricted by the inclined portion 15 of the lower leaf spring 3. Also, even if the lower end of the lower leaf spring 3 is moved inward in the vehicle width direction with respect to the rubber cap 13, the lower end of the lower arm 10 is pivoted to the lower side. The side leaf spring 3 is formed so as not to come off.

  Next, the operation of this embodiment will be described.

  When the left front wheel 2 receives an upward force from the ground, the force acts on the leaf springs 3 and 4 and the shock absorber 12 through the lower arm 10 on the left side. The lower arm 10 is thereby pivoted upward. In addition, the upper and lower leaf springs 3 and 4 are deformed so that the left end jumps up to absorb the aforementioned force. At this time, the left end portion of the upper stage leaf spring 4 is slid to the left (tip direction) with respect to the lower stage leaf spring 3 and the rubber cap 13 in accordance with the above-described deformation. At this time, the left end of the upper stage leaf spring 4 is disposed in advance inward in the vehicle width direction from the left end of the lower stage leaf spring 3. Therefore, the inclined portion 17 of the upper leaf spring 4 can be prevented or suppressed from contacting the rear inner surface 13 b of the rubber cap 13.

  When the lower arm 10 is pivoted to the preset upper limit position, the left end of the upper leaf spring 4 is slid to the vicinity of the left end of the lower leaf spring 3. However, basically, the upper leaf spring 4 does not protrude leftward beyond the lower leaf spring 3. Further, since the end shape of the upper leaf spring 4 is the same as the end shape of the lower leaf spring 3, the inclined portion 17 of the upper leaf spring 4 also protrudes leftward beyond the inclined portion 15 of the lower leaf spring 3. I have not. Therefore, the inclined portion 17 of the upper leaf spring 4 can be prevented or suppressed from contacting the rear inner surface 13 b of the rubber cap 13.

  Thus, the upper-stage leaf spring 4 is formed shorter than the lower-stage leaf spring 3 and disposed so as to separate the inclined portion 17 inward in the vehicle width direction from the rubber cap 13. Therefore, when the leaf springs 3 and 4 are deformed by receiving an upward force from the lower arm 10, the inclined portion 17 of the upper-stage leaf spring 4 can be prevented or suppressed from contacting the rubber cap 13. And it can prevent or suppress that the rubber cap 13 is pushed and spread by the inclination part 17, and it can prevent or suppress that a crack is generated in the rubber cap 13.

  The inclined portion 17 of the upper leaf spring 4 is formed so as not to protrude outward in the vehicle width direction from the inclined portion 15 of the lower leaf spring 3 when the lower arm 10 is rotated to the upper limit position. Therefore, even when the lower arm 10 is pivoted to the upper limit position, the inclined portion 17 of the upper leaf spring 4 can be prevented or suppressed from contacting the rubber cap 13.

  Although the embodiments of the present invention have been described in detail above, the present invention can be applied to other embodiments as follows.

  (1) The two leaf springs 3 and 4 are stacked vertically, but the present invention is not limited to this. The leaf spring may be three or more stacked vertically.

  In this case, the leaf spring may be formed shorter toward the upper stage. Further, it is preferable that both ends of the leaf spring be disposed more inward in the vehicle width direction as the upper side of the leaf spring. Further, when the lower arm 10 is pivoted to the upper limit position, it is preferable that none of the leaf springs project outward in the vehicle width direction from the leaf springs of the lowermost stage.

  (2) Straight portions 14 and 16 are formed at the front edge of the end portions of the leaf springs 3 and 4, and inclined portions 15 and 17 are formed at the rear edge of the end portions of the leaf springs 3 and 4 It is not limited to As shown in FIG. 7, sloped portions 25, 26 may be formed on both the front end edge and the rear end edge of the leaf springs 23, 24. Also, a slope may be formed at the end front edge of the leaf spring (not shown) and a straight portion may be formed at the end rear edge of the leaf spring.

  (3) The upper stage leaf spring 4 is formed to have the same shape as that of the lower stage leaf spring 3, but the present invention is not limited to this. When the vehicle is stopped, the inclined portion 17 of the upper leaf spring 4 may be displaced inward in the vehicle width direction by at least a displacement amount L with respect to the inclined portion 15 of the lower leaf spring 3 and the rear inner surface 13b of the rubber cap.

  The configurations of the embodiments described above can be partially or totally combined unless there is a particular contradiction. The embodiments of the present invention are not limited to the above-described embodiments, and all variations, applications, and equivalents included in the concept of the present invention defined by the claims are included in the present invention. Accordingly, the present invention should not be interpreted in a limited manner, and can be applied to any other technology falling within the scope of the present invention.

1 Independent Suspension Device 3 Lower Leaf Spring 4 Upper Leaf Spring 10 Lower Arm 13 Rubber Cap 15 Sloped Part

Claims (3)

A plurality of leaf springs provided so as to extend between the lower arms of the left and right independent suspension devices and disposed one on top of the other with tapered end portions;
And a rubber cap for bundling the ends of these leaf springs,
The leaf spring on the upper side is formed to be shorter than the leaf spring on the lower side, and the inclined portion at the end portion is arranged to be spaced apart inward in the vehicle width direction from the rubber cap. Horizontally placed leaf spring structure.   The inclined portion of the leaf spring on the upper side is formed not to protrude outward in the vehicle width direction from the inclined portion of the leaf spring on the lower side when the lower arm is rotated to the upper limit position. The horizontally placed leaf spring structure according to claim 1. At an end front edge of the leaf spring, a straight portion extending in a straight line along the vehicle width direction is formed.
The inclined portion is formed at an end rear edge of the leaf spring,
The inclined portion is inclined forward as it goes outward in the vehicle width direction,
The rubber cap is formed in a tubular shape having a rectangular cross section, and a front inner surface is formed in a planar shape along the straight portion of the lower leaf spring, and a rear inner surface is in the lower leaf spring. The horizontal leaf spring structure according to claim 1, wherein the horizontal leaf spring structure is formed in a planar shape along the inclined portion.

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