JP2016141386A - Strut type suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strut type suspension device which achieves stable damping performance of a damper strut even when processing accuracy of a terminal of a coil spring is not sufficient.SOLUTION: A support mechanism 7 is disposed between a lower spring seat 10 and a cylinder case 5a. The support mechanism 7 supports the lower spring seat 10 in a state where the lower spring seat 10 may tilt relative to a center axis O2 of a coil spring 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a strut suspension device including a coil spring and a damper trast.

  As is well known, the strut type suspension device includes a coil spring and a damper trat. In this type of strut suspension device, a spring seat is fixed to each cylinder case and piston rod of a damper trast, and a coil spring is interposed between the pair of spring seats (for example, Patent Document 1). reference).

  The coil spring held in this manner has an action of canceling a bending moment that is structurally generated in the damper trast.

JP 2003-63226 A

  Incidentally, the coil spring in the strut type suspension device generally has a predetermined processing error at the terminal.

  However, such processing errors make it difficult to evenly press the spring seat fixed to the damper trast by the coil spring. Specifically, for example, when the shape accuracy of the coil spring is low, individual differences occur in the contact position with the spring seat and the load distribution when the spring seat is pressed.

  And when a coil spring presses in the state which biased the spring seat in this way, there exists a possibility that coil spring itself may generate a new bending moment with respect to a damper trat. Such a bending moment may cause an increase in friction of the damper trat and a difference between the left and right sides, which may make it difficult to achieve a stable damping performance of the damper trat.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a strut-type suspension device capable of realizing stable damping performance of a damper trast even when the processing accuracy of the end of the coil spring is not sufficient. And

  A strut-type suspension device according to an aspect of the present invention includes a coil spring that elastically receives vertical movement of a wheel with respect to a vehicle body, a cylinder case, and a piston rod that is movable forward and backward with respect to the cylinder case. A damper trast that is loosely inserted into the inner space of the spring and transmitted to the vehicle body is damped, and is connected to the cylinder case and the piston rod, respectively, and the coil spring is pressed. A pair of spring seats, and between the cylinder case and the spring seat, or at least one of the piston rod and the spring seat, and the spring seat of the coil spring A support mechanism that supports tilting with respect to the central axis. Those were.

  According to the strut type suspension device of the present invention, stable damping performance of the damper trast can be realized even when the processing accuracy of the end of the coil spring is not sufficient.

The principal part sectional view of a strut type suspension device concerning a 1st embodiment of the present invention. Same as above, plan view of lower spring seat Same as above, enlarged sectional view of the main part showing the support structure of the lower spring seat Same as the above, (a) is an explanatory view schematically showing the relationship between the coil spring and the spring seat, and (b) is an explanatory view schematically showing a comparative example of the relationship between the coil spring and the spring seat. Same as above, enlarged cross-sectional view of the main part showing a modification of the support structure of the lower spring seat Same as above, enlarged cross-sectional view of the main part showing a modification of the support structure of the lower spring seat Sectional drawing of the principal part of a strut type suspension apparatus concerning the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to a first embodiment of the present invention, FIG. 1 is a cross-sectional view of a main part of a strut suspension device, FIG. 2 is a plan view of a lower spring seat, and FIG. 3 is an enlarged main part showing a support structure of the lower spring seat. FIG. 4A is an explanatory view schematically showing the relationship between the coil spring and the spring seat, and FIG. 4B is an explanatory view schematically showing a comparative example of the relationship between the coil spring and the spring seat. FIG. 5 is an enlarged cross-sectional view of a main part showing a modification of the support structure for the lower spring seat, and FIG. 6 is an enlarged cross-sectional view of a main part showing a modification of the support structure for the lower spring seat.

  As shown in FIG. 1, a strut suspension device (hereinafter referred to as “suspension device”) 1 employed in the present embodiment is used for a front suspension of a four-wheel drive vehicle, for example. In FIG. 1, the right front wheel side is illustrated.

  The suspension device 1 has a suspension mounting portion 2 and a strut 3 provided on a wheel apron on the vehicle body side. The strut 3 includes a coil spring 4 that elastically receives the vertical movement of the wheel with respect to the vehicle body, and a damper strut 5 that is loosely inserted in an inner space of the coil spring 4 and attenuates the vertical movement of the wheel. ing.

  The damper trast 5 includes a cylinder case 5a and a piston rod 5b that is inserted into and supported by the cylinder case 5a so as to freely advance and retract. A bracket 6 is fixed to the lower end of the cylinder case 5a, and the bracket 6 is fixed to a knuckle housing (not shown) for fixing a wheel. The upper end of the piston rod 5b is supported via a bearing 9 on a strut mount 8 mainly composed of an elastic body such as rubber, and the strut mount 8 is fixed to the suspension mounting portion 2.

  A lower spring seat 10 is supported in a tiltable manner in the middle of the cylinder case 5 a provided in the damper trast 5 via a support mechanism 7. An upper spring seat 11 is fixed between the upper portion of the piston rod 5 b and the bearing 9. In addition, a coil spring 4 is pressed between the pair of spring seats 10 and 11.

  Here, the center part of the lower spring seat 10 is disposed at a position offset from the center axis O1 of the damper trast 5, and the support mechanism 7 is connected to the offset center part, whereby the lower spring seat 10 can tilt. It is supported by. The lower spring seat 10 is thus supported in an offset state, whereby the central axis O2 of the coil spring 4 is inclined at a predetermined angle with respect to the central axis O1 of the damper trast 5. . The inclination angle of the central axis O2 is set in advance by experiments and the like to a value effective for canceling the bending moment generated in the structure of the damper trat 5 by the coil spring 4.

  The upper part of the cylinder case 5a is covered with a telescopic dust cover 12 formed in a substantially cylindrical and bellows shape, and its lower end is seated on the lower spring seat 10. Further, the upper surface of the dust cover 12 is positioned above the upper end of the cylinder case 5a, and a helper spring 13 is projected from the upper surface of the dust cover 12. The helper spring 13 is inserted into the piston rod 5b, and its upper surface is in contact with the upper spring seat 11 in a slightly compressed state. The helper spring 13 has a relatively thick wall and a bellows-like expandable shape.

  The dust cover 12 and the helper spring 13 are an integrally formed product made of an elastic body such as urethane rubber. The thickness and shape of the helper spring 13 are obtained in advance through experiments or the like so that the coil spring 4 can be assisted. Is set.

  Next, the support structure of the lower spring seat 10 in the present embodiment will be specifically described. As shown in FIGS. 1 and 2, the lower spring seat 10 is formed of a sheet metal member having a substantially disk shape. A bush receiving portion 21 having a partially spherical shape is formed at the center portion of the lower spring seat 10 so as to protrude upward. A strut insertion hole 22 into which the cylinder case 5a of the damper trast 5 can be freely inserted is opened on one side of the bush receiving portion 21.

  As shown in FIGS. 1 and 3, the support mechanism 7 that supports the lower spring seat 10 includes a bracket 25 fixed to the outer peripheral surface of the cylinder case 5 a by welding or the like, and an arm extended from the bracket 25. A bushing 28 which is mainly composed of an elastic body such as rubber, and is bonded and fixed to the surface of the joint ball 27 in a partial spherical shape. And is configured.

  The lower spring seat 10 is supported so as to be tiltable with respect to the central axis O <b> 2 of the coil spring 4 by bonding and fixing the inner surface of the bush receiving portion 21 to the surface of the bush 28.

  According to such an embodiment, the support mechanism 7 is interposed between the lower spring seat 10 and the cylinder case 5 a, and the lower spring seat 10 is moved with respect to the central axis O <b> 2 of the coil spring 4 by the support mechanism 7. By supporting in a tiltable state, even when the processing accuracy of the end of the coil spring 4 is not sufficient, stable damping performance of the damper trast 5 can be realized.

  That is, by supporting the lower spring seat 10 so as to be tiltable, for example, as shown in FIG. 4A, the lower spring seat 10 can be tilted following the shape of each terminal of the coil spring 4. . Thereby, even when the processing accuracy of each end of the coil spring 4 is not sufficient, each end of the coil spring 4 has a uniform load distribution without causing the end portions of the coil spring 4 to come into contact with the lower spring seat 10 and the upper spring seat 11. Can be brought into contact with each other. Therefore, it is possible to prevent a new bending moment from being generated in the damper trast 5 due to the input of biasing forces biased to the spring seats 10 and 11, and the coil spring in a direction substantially along the direction of the central axis O2. With the urging force of 4, the bending moment generated in the structure of the damper trast 5 can be preferably canceled. FIG. 4B shows the operation when both the lower spring seat 10 and the upper spring seat 11 are rigidly fixed to the cylinder case 5a and the piston rod 5b as a comparative example. It is. In this case, a bending moment M caused by the end contact of the end of the coil spring 4 is applied to the damper trast via the lower spring seat 10 and the upper spring seat 11.

  Further, since the support mechanism 7 is configured to elastically connect the lower spring seat 10 and the cylinder case 5a via the bush 28, the bush 28 is elastically configured to relatively rotate the lower spring seat 10 and the cylinder case 5a. It can also function as an insulator for restricting.

  Here, it is preferable that the support mechanism 7 allows only the tilting of the lower spring seat 10 and restricts sliding or the like in a direction perpendicular to the central axis O2 of the coil spring 4. Therefore, for example, as shown in FIG. 5, the bush 28 is configured by a multi-layer structure including a plurality of elastic body layers 28 a in which a metal rigid body layer 28 b is interposed in an intermediate layer. Can be made relatively higher than the rigidity in the tilting direction.

  Furthermore, for example, as shown in FIG. 6, in order to realize a suitable tilting operation even when the rigid body layer 28b is interposed, a hollow portion (crank) 27c is formed near the center of the bush 28, and tilting is performed. It is also possible to make the direction rigidity relatively lower than the rigidity in the sliding direction.

  Next, FIG. 7 relates to a second embodiment of the present invention, and FIG. 7 is a cross-sectional view of the main part of the strut suspension device. Note that this embodiment mainly differs from the first embodiment described above in that the upper spring seat is tiltably supported. In addition, about the structure similar to the above-mentioned 1st Embodiment, a same sign is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 7, the tip end side of the piston rod 5b is loosely inserted into the upper spring seat 11 of the present embodiment.

  Further, a support mechanism 30 is interposed between the bearing 9 fixed to the piston rod 5 b and the upper spring seat 11, and the upper spring seat 11 can be tilted to the bearing 9 via the support mechanism 30. It is supported by.

  More specifically, for example, as shown in FIG. 7, the support mechanism 30 includes a bush mounting portion 31 having a hook shape that is rotatably connected to the strut mount 8 via a bearing 9, and an elastic material such as rubber. And a bush 32 that is mainly composed of a body and is bonded and fixed inside the bush mounting portion 31. Further, the bush 32 is provided with a cavity 32a for adjusting the rigidity.

  The upper surface of the upper spring seat 11 is bonded and fixed to the bush 32 of the support mechanism 30 configured as described above, so that the upper spring seat 11 can tilt with respect to the central axis O2 of the coil spring 4. It is supported.

  According to such an embodiment, substantially the same operations and effects as the first embodiment described above can be achieved.

  In addition, this invention is not limited to each embodiment described above, A various deformation | transformation and change are possible, and they are also in the technical scope of this invention. For example, it goes without saying that the configurations of the above-described embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... Suspension apparatus 2 ... Suspension attaching part 3 ... Strut 4 ... Coil spring 5 ... Damper path 5a ... Cylinder case 5b ... Piston rod 6 ... Bracket 7 ... Support mechanism 8 ... Strut mount 9 ... Bearing 10 ... Lower spring seat (spring seat) )
11 ... Upper spring seat (spring seat)
DESCRIPTION OF SYMBOLS 12 ... Dust cover 13 ... Helper spring 21 ... Bush receiving part 22 ... Strut insertion hole 25 ... Bracket 26 ... Arm part 27 ... Joint ball 28 ... Bush 28a ... Elastic body layer 28b ... Rigid body layer 28c ... Hollow part 30 ... Support mechanism 31 ... Bush mounting part 32 ... Bush 32a ... Cavity

Claims (4)

A coil spring that elastically receives the vertical movement of the wheel with respect to the vehicle body,
A damper case that has a cylinder case and a piston rod that is movable forward and backward with respect to the cylinder case, and that is loosely inserted into an inner space of the coil spring and attenuates the vertical movement of the wheel transmitted to the vehicle body;
A pair of spring seats connected to the cylinder case and the piston rod, respectively, and interposed in a state where the coil spring is pressed;
It is interposed between the cylinder case and the spring seat, or at least one of the piston rod and the spring seat, and supports the spring seat so that it can tilt with respect to the central axis of the coil spring. A strut-type suspension device. The support mechanism has a bush fixed to the spring seat,
The strut-type suspension device according to claim 1, wherein the spring seat is allowed to tilt by elastic deformation of the bush.   The bush is configured by a multilayer structure composed of a plurality of elastic body layers with a rigid body layer interposed in an intermediate layer, and the rigidity of the spring seat in the sliding direction is greater than the rigidity in the tilting direction by the rigid body layer. The strut suspension device according to claim 2, wherein the suspension is set to be relatively high.   The bush has a hollow portion therein, and the hollow portion is set so that rigidity in the tilting direction of the spring seat is relatively lower than rigidity in a sliding direction. The strut suspension device according to claim 1 or 2.

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