JP2009248880A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device having a function for absorbing impact force in a vehicle longitudinal direction and capable of achieving careful consideration for other on-vehicle apparatuses after absorbing. <P>SOLUTION: This suspension device 1 is provided with: a support means for rotatably supporting a wheel; a connection means 2 for rockably connecting the support means with respect to a vehicle longitudinal member 9 constituting a chassis; a first torsional elastic means 5 connected to the connection means 2 and extended to a vehicle front part; and a second torsional elastic means 6 connected to a vehicle front part end of the first torsional elastic means 5, extended to a vehicle rear part, and connected to the vehicle longitudinal member 9. The second torsional elastic means 6 wraps the first torsional elastic means 5, and a connection member 7 is provided for connecting a vehicle front part end of the second torsional elastic means 6 and a vehicle width direction member 18 constituting a vehicle front part end of the chassis. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a suspension device suitable for being applied to vehicles such as passenger cars, trucks, and buses.

  In a suspension device applied in a vehicle, a knuckle that rotatably supports a wheel is connected to a chassis side via an arm or a link, and the knuckle or arm or link is connected to a body side via a shock absorber and a spring. In addition, a structure is adopted in which a tie rod constituting the steering mechanism is connected to a knuckle or a strut outer shell of a shock absorber via a knuckle arm.

  In such a suspension device, the vertical dimension between the hood and the suspension tower of the vehicle is sufficiently large by reducing the vertical dimension of the suspension device and lowering the height of the suspension tower, which is the part connecting the shock absorber on the body side. It is preferable from the viewpoint of a request for pedestrian protection mainly.

  For this purpose, as described in Patent Document 1, for example, instead of a spiral spring, a torsion bar spring is used to connect the arm or link to the chassis side. As a result, a torsional elastic force is generated in the torsion bar spring based on the relative displacement between the arm or the link and the chassis side that occurs with the bounding and rebounding of the wheel. Wheel grounding.

  In the suspension device described in Patent Document 1, in order to generate a torsional elastic force on the torsion bar spring based on the relative displacement between the arm or link and the chassis side, the torsion bar spring is moved in the vehicle longitudinal direction. It has been proposed that the torsion bar spring supports and absorbs the impact force in the vehicle front-rear direction by making use of the necessity to extend.

In such a torsion bar spring described in Patent Document 1, when the impact force acting in the vehicle front-rear direction at the time of frontal collision or offset frontal collision of the vehicle exceeds a certain threshold value, the vehicle interior space of the vehicle is intentionally Other parts, especially the hood and the chassis located under the hood, are compressed in the longitudinal direction of the vehicle and crushed, that is, crushed, so as to absorb the impact force to secure the passenger compartment and secure passengers in the passenger compartment. It is required to protect.
Japanese Patent Application Laid-Open No. 11-245639

  However, in the torsion bar spring of the suspension device described in Patent Document 1 described above, which part of the torsion bar spring in the vehicle front-rear direction is crushed when the load acting in the vehicle front-rear direction exceeds a certain threshold value. It is difficult to prevent the torsion bar springs after being controlled and crushed from interfering with the tires, shock absorbers or other in-vehicle devices constituting the wheels, and absorb the impact force in the vehicle longitudinal direction. There was a problem that detailed consideration for other in-vehicle devices after the function was not realized.

  In view of the above problems, an object of the present invention is to provide a suspension device that has a function of absorbing an impact force in the vehicle front-rear direction and can realize detailed consideration for other in-vehicle devices after absorption. To do.

In order to solve the above problem, the suspension device according to the present invention is:
Support means for rotatably supporting the wheels, connection means for swingably connecting the support means to a vehicle longitudinal member constituting the chassis, and a first twist joined to the connection means and extending forward of the vehicle Elastic means and second torsion elastic means joined to the vehicle front-rear direction member joined to the vehicle front end of the first torsion elastic means, and the second torsion elastic means A coupling member that has a form of enclosing the first torsional elastic means and connects a vehicle front end portion of the second torsional elastic means and a vehicle width direction member constituting the vehicle front end portion of the chassis; It is characterized by.

  The suspension device may be any of a double wishbone type, a multi-link type, a strut type, and a trailing arm type. For example, in the case of a double wishbone type, the wheel and the road surface of the upper arm and the lower arm. The lower arm close to the contact surface corresponds to the connecting means. The lower arm may be any of A arm, T arm, and L arm. Further, if the suspension device is a strut type, the arm corresponds to the connecting means, and if the suspension device is a multi-link type, one or more links close to the contact surface between the wheel and the road surface correspond to the connecting means. .

  The wheel refers to a combination of a tire and a wheel, and the support means refers to a knuckle that rotatably supports the wheel. The first torsional elastic means corresponds to a torsion bar spring, and the second torsional elastic means corresponds to a cylindrical reaction spring.

  Further, since it is assumed that the suspension device is on the front side, the vehicle longitudinal direction member corresponds to a so-called front side member, and the vehicle width direction member typically corresponds to a radiator support. Further, since the vehicle width direction member is located in front of the vehicle with respect to the vehicle front end portions of the first torsion elastic means and the second torsion elastic means, the coupling member is constituted by a connecting plate extending in the vehicle front-rear direction. .

Here, in the suspension device,
It is preferable that the compressive strength in the vehicle longitudinal direction at a predetermined location of the second torsional elastic means is smaller than the compressive strength in the vehicle longitudinal direction other than the predetermined location.

  According to this, at the time of a frontal collision of the vehicle or an offset frontal collision, the vehicle longitudinal direction impact force acting on the second torsional elastic means from the vehicle width direction member via the coupling member has exceeded a certain threshold value. In this case, the second torsion elastic means can be intentionally crushed at the predetermined position in the vehicle front-rear direction.

Furthermore, in the suspension device,
It is preferable that the compressive strength in the vehicle front-rear direction at the predetermined location is smaller than the compressive strength in the vehicle front-rear direction of the first torsional elastic means.

  According to this, at the time of a frontal collision of the vehicle or an offset frontal collision, the vehicle longitudinal direction impact force acting on the second torsional elastic means from the vehicle width direction member via the coupling member has exceeded a certain threshold value. In this case, the predetermined portion of the second torsion elastic means can be crushed before the first torsion elastic means.

  Accordingly, the first torsion elastic means can be bent by causing the second torsion elastic means that has been crushed and deformed to interfere with the first torsion elastic means. Thus, after the collision further proceeds, the vehicle front-rear direction gap between the vehicle front end portion of the first torsion elastic means and the vehicle width direction member disappears, and the first torsion elastic means has the vehicle width direction. The impact force in the vehicle front-rear direction is directly transmitted from the member, and the first torsion elastic means is bent more greatly at the bent position by the impact force, and the impact force is applied by the first torsion elastic means. Can be absorbed.

  That is, the impact force in the vehicle front-rear direction is first crushed by the second torsional elastic means, and then the first torsional elastic means is bent, so that the impact force can be more effectively absorbed and the vehicle interior space can be absorbed. To protect the passengers. In the suspension device having such a configuration, the coupling at the predetermined position and the predetermined position of the second torsional elastic means is appropriately set from the vehicle width direction member at the time of a vehicle frontal collision or an offset frontal collision. When the impact force in the vehicle longitudinal direction acting on the second torsional elastic means via the member exceeds a certain threshold value, the energy absorption amount and the deformation mode with respect to the impact force can be set to desired values. Thereby, the energy absorption amount of the whole vehicle can be increased together with the energy absorption amount of the vehicle longitudinal member.

  At the same time, the second torsional elastic means can be crushed at the predetermined place where the presetting is possible, and the first torsional elastic means can be bent in the vicinity of the predetermined place. The second torsional elastic means and the bent first torsional elastic means interfere with a tire constituting the wheel, a shock absorber constituting the suspension device, and other in-vehicle devices, as described above. Can be avoided by appropriately setting. Thereby, even after the impact force is absorbed by the second torsional elastic means and the first torsional elastic means, it is possible to realize detailed consideration for other in-vehicle devices.

  Furthermore, the first torsion elastic means and the second torsion elastic means are both formed as two torsion bar springs, and they are connected by gears. By adopting a form in which the torsion elastic means is enclosed, it is possible to easily realize the crushing of the second torsion elastic means by the impact force before the first torsion elastic means.

Here, in the suspension device,
It is preferable that the torsional elasticity of the coupling member around the vehicle front-rear direction is smaller than the compression rigidity in the vehicle front-rear direction.

  According to this, since the compression rigidity in the vehicle front-rear direction of the coupling member can be increased at the time of a frontal collision or an offset frontal collision of the vehicle, the first through the coupling member from the vehicle width direction member. The impact force in the vehicle longitudinal direction can be more efficiently transmitted to the two-twist elastic means.

  At the same time, in the initial stage of the collision, a vehicle front-rear direction clearance between the vehicle front end portion of the first torsion elastic means and the vehicle width direction member is secured, and the first torsion elastic means is provided in the vehicle front-rear direction. By not transmitting the impact force, the second torsion elastic means can be more reliably crushed before the first torsion elastic means.

  Furthermore, since the torsional elasticity of the coupling member can be reduced, the coupling means is coupled to the chassis by coupling the vehicle front end portion of the second torsional elastic means to the vehicle width direction member by the coupling member. By swinging with respect to the first torsion elastic means and the second torsion elastic means, it is possible to avoid the coupling member from affecting the relation between the torsional elastic force generated by the first torsion elastic means and the swing, that is, the spring constant. be able to.

Here, in the suspension device,
It is preferable that a plurality of joint portions of the coupling member with the second torsional elastic means are provided in the vehicle front-rear direction.

  According to this, when joining the coupling member to the second torsional elastic means, it is possible to avoid as much as possible that the coupling member restrains the circumferential torsional displacement of the second torsional elastic means. This also causes the relationship between the torsional elastic force generated by the first torsional elastic means and the second torsional elastic means and the oscillation, that is, the spring constant, as the connecting means swings with respect to the chassis. It is possible to avoid the influence of the coupling member as much as possible.

In the suspension device, as specific means for making the torsional elasticity of the coupling member around the vehicle longitudinal direction smaller than the compression rigidity in the vehicle longitudinal direction,
In addition to making the cross-sectional shape of the coupling member perpendicular to the vehicle front-rear direction U-shaped, the coupling member may be a flat plate, and a rib extending in the vehicle front-rear direction may be provided at the center in the vehicle width direction. Various shapes can be selected.

Furthermore, as a specific form for realizing the suspension device,
The connecting means is connected to the vehicle longitudinal member at two connecting points, and the vehicle rear end of the first torsional elastic means is a portion constituting the vehicle rear side connecting point of the support means. It is good also as joining.

In this case,
It is preferable that a portion constituting a connecting point on the vehicle front side of the connecting means has a hollow cylindrical portion with the vehicle longitudinal direction as an axis, and the first torsional elastic means is inserted into the hollow cylindrical portion.

  According to this, the length of the first torsional elastic means protruding forward of the vehicle with respect to the connection means can be shortened by the interval length of the two connection points in the connection means. The dimension of the suspension device in the longitudinal direction of the vehicle can be made as small as possible. Thereby, by providing the first torsional elastic means, it is possible to prevent the vehicle interior space and the engine compartment space from being restricted.

  Furthermore, when the two connection points are constituted by known bushes, the central axes of the two bushes are made to coincide with each other so that the swinging of the connection means relative to the vehicle longitudinal member is smoother. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, while having the function which absorbs the impact force of a vehicle front-back direction, the suspension apparatus which can implement | achieve the detailed consideration to the other vehicle equipment after absorbing can be provided.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing an embodiment of a suspension device according to the present invention.

  As shown in FIG. 1, the suspension device 1 of this embodiment is of a double wishbone type, and includes a knuckle (not shown), a shock absorber (not shown), a lower arm 2, a bush 3, a bush 4, and a torsion bar spring. 5, a reaction spring 6, and a connecting plate 7. In FIG. 1, F indicates the front of the vehicle, and L indicates the outer side in the vehicle width direction, that is, the left side of the vehicle.

  Here, the knuckle rotatably supports a tire and a wheel (not shown), and a lower end portion thereof is connected to an outer end portion in the vehicle width direction of the lower arm 2 via a ball joint B / J.

  Further, the lower arm 2 is configured by a so-called A arm that extends in the vehicle width direction and is formed so that the inner side in the vehicle width direction branches into a bifurcated shape. In addition, the outer end of the lower arm 2 in the vehicle width direction, that is, the apex side of the A arm is connected to the lower end of the knuckle through a ball joint B / J.

  In addition, among the two connecting points on the inner side in the vehicle width direction of the lower arm 2, that is, on the opposite side of the apex of the A arm, the connecting point on the vehicle front side is swingable to the suspension member 8 via the bush 3. And a connecting point on the vehicle rear side is swingably connected to the suspension member 8 via the bush 4. Further, the suspension member 8 is joined to the front side member 9, whereby the knuckle and the front side member 9 are connected via the lower arm 2.

  Furthermore, an outer cylindrical portion 2a is formed at a connecting point on the vehicle front side of the lower arm 2, and an inner cylindrical portion 2b is coaxially disposed on the inner peripheral side of the outer cylindrical portion 2a, and the outer cylindrical portion 2a An elastic member such as rubber rubber is filled in the annular columnar radial gap with the inner cylindrical portion 2b to form a bush 3, and a female screw is formed on the inner peripheral surface of the inner cylindrical portion 2b.

  A female screw having the same size as the female screw of the inner cylindrical portion 2b is formed on the inner peripheral surface of the hole portion 10a formed in the lower arm bracket 10 rigidly coupled to the suspension member 8 and centered in the vehicle front-rear direction. By screwing the male screw of the hollow bolt nut 11 from the front of the vehicle to the female screw of the hole 10a and the female screw of the inner cylindrical portion 2b, and screwing the nut 12 to the vehicle rear side of the hollow bolt nut 11, The inner cylindrical portion 2 b of the lower arm 2 is connected to the lower arm bracket 10.

  Further, an outer cylindrical portion 2c is formed at a connecting point on the vehicle rear side of the lower arm 2, and an inner cylindrical portion 2d is coaxially arranged on the inner peripheral side of the outer cylindrical portion 2c, and the outer cylindrical portion 2c An elastic member such as rubber rubber is filled in the annular columnar radial gap with the inner cylindrical portion 2d to form a bush 4, and a female screw is formed on the inner peripheral surface of the inner cylindrical portion 2d.

  The lower arm bracket 13 rigidly coupled to the suspension member 8 is formed with a hole 13a centered in the vehicle front-rear direction, and a bush bolt 14 having a male screw threadedly engaged with the female screw of the inner cylindrical portion 2b is provided in the hole portion. The inner cylinder portion 2d of the lower arm 2 is connected to the lower arm bracket 13 by being inserted from the rear side of the vehicle 13a and the male screw of the bush bolt 14 is screwed into the female screw of the inner cylindrical portion 2d.

  The hole portion 10a of the lower arm bracket 10 and the hole portion 13a of the lower arm bracket 13 are arranged coaxially, so that the outer cylindrical portion 2a and the outer cylindrical portion 2c of the lower arm 2 are centered on the same axis, and the suspension member 8 and thus the front The side member 9 is swingably connected.

  Further, a shallow bottom cylindrical clasp 15 opened to the vehicle rear side is fitted to the vehicle front side end portion of the outer cylindrical portion 2c of the lower arm 2, and a female axis is located near the central axis of the clasp 15. A male serration that can be fitted to the female serration is formed at the rear end portion of the torsion bar spring 5, and the torsion bar spring 5 is inserted through the hollow bolt nut 11 from the front of the vehicle. The lower arm 2 and the torsion bar spring 5 are joined by fitting the male serration of the torsion bar spring 5 to the clasp 15.

  The reaction spring 6 has a bottomed cylindrical shape that is coaxially arranged so as to enclose the torsion bar spring 5, and a female side serration is formed on the bottomed portion 6 a at the front end of the reaction spring 6. A male serration that can be fitted to the female serration is formed at the front end of the torsion bar spring 5, and the male serration of the torsion bar spring 5 is changed to the female serration at the front end of the reaction spring 6. By fitting, the reaction spring 6 and the torsion bar spring 5 are joined.

  Further, a flange portion 6b that protrudes radially outward is formed at the vehicle rear side end portion of the reaction spring 6, and the flange portion 6b is in contact with the vehicle front end surface of the lower arm bracket 10, so that the flange portion 6b and the lower arm Reaction spring bolts 16 are inserted from the front of the vehicle through holes provided at equal intervals around the circumference of the bracket 10 and the nuts 17 are screwed from the rear of the vehicle to the reaction springs. 6 is joined to the lower arm bracket 10 at the rear end of the vehicle.

  Further, the shock absorber has an upper end portion connected to the vehicle body via an upper support (not shown), and a lower end portion of the strut outer shell is connected to an upper end surface near the knuckle of the lower arm 2 so that the tire and the wheel Due to the vibration from the road surface transmitted through the knuckle, the damping force prevents the knuckle from continuing to vibrate by its damping force.

  In addition, the torsion bar spring 5 and the reaction spring 6 are transmitted from the tire and wheel to the vehicle body side via the knuckle by the torsional elastic force generated by the swing of the lower arm 2 due to the bound rebound of the tire and wheel. In addition to having a buffering action to reduce vibrations, it ensures contact with the road surface of the tire.

  In addition, in the place mentioned above, a tire and a wheel correspond to a wheel, and a knuckle comprises the support means which supports a wheel rotatably. The torsion bar spring 5 corresponds to the first torsion elastic means, and the reaction spring 6 corresponds to the second torsion elastic means. Furthermore, the connecting plate 7 constitutes a coupling member. The front side member 9 corresponds to a vehicle front-rear direction member constituting the chassis, and the radiator support 18 corresponds to a vehicle width direction member constituting the chassis.

  Further, the vehicle front end portion of the reaction spring 6 is coupled to the radiator support 18 by the connecting plate 7. Hereinafter, the detailed form of the connecting plate 7 and the details of the joining mode to the reaction spring 6 will be described with reference to the drawings.

  2 is a schematic cross-sectional view showing an AA cross section of the suspension apparatus according to the present invention shown in FIG. 1, and FIG. 3 is a schematic cross-sectional view showing a BB cross section of the suspension apparatus according to the present invention shown in FIG. is there. FIG. 4 is a schematic cross-sectional view showing a CC cross section of the suspension device according to the present invention shown in FIG.

  As shown in FIG. 2, the cross-sectional shape of the connecting plate 7 perpendicular to the vehicle front-rear direction is a U-shape that opens upward. As a result, the torsional elasticity of the connecting plate 7 around the vehicle longitudinal direction is made smaller than the compression rigidity in the vehicle longitudinal direction.

  Further, as shown in FIGS. 3 and 4, a plurality of connecting portions of the connecting plate 7 with the reaction spring 6 are provided in the vehicle front-rear direction here, and the upper surface of the connecting plate 7 is reacted at each of the connecting portions. The connecting plate bolt 19 is inserted into two holes formed in advance in the flat portion in contact with the flat portion provided on the lower surface of the spring 6, and the nut 20 is screwed into the connecting plate bolt 19. . Further, the vehicle front side portion of the reaction spring 6 is fastened and joined to the radiator support 18 by the radiator support bolt 21.

  Further, as shown in FIG. 4, the compressive strength in the vehicle longitudinal direction at a predetermined location of the reaction spring 6 is made smaller than the compressive strength in the vehicle longitudinal direction other than the predetermined location. Specifically, as shown in FIG. 4, a groove-like suddenly deformed portion 22 is provided on the outer peripheral surface of the cylindrical reaction spring 6.

  Further, the external dimensions and material of the torsion bar spring 5, the external dimensions of the reaction spring 6, and the reaction spring 6 are set so that the compressive strength in the vehicle longitudinal direction of the suddenly deformed portion 22 is smaller than the compressive strength of the torsion bar spring 5 in the vehicle longitudinal direction. The material is appropriately selected.

  The mutual positional relationship among the connecting plate 7, the radiator support 18, the suspension member 8 and the front side member 9 of the suspension device 1 described above will be described with reference to the drawings. FIG. 5 is a schematic perspective view showing a structure including a chassis of a vehicle to which the suspension device according to the present invention is applied.

  As shown in FIG. 5, the front side member 9 is provided in a pair of left and right with respect to the center in the vehicle width direction in the vehicle front-rear direction, and a front bumper reinforcement 23 is joined to the vehicle front end portion of the front side member 9. A radiator support 18 having a square shape is joined to a portion of the side member 9 located behind the front bumper reinforcement 23 in the vehicle.

  The lower side portion of the radiator support 18 is offset downward from the front side member 9, and a sub front bumper reinforcement 24 is joined to the front of the variable portion of the radiator support 18. Although illustration of the suspension device 1 and the individual elements constituting the suspension device 1 is omitted here, the connecting plate 7 that connects the reaction tube 6 and the lower side of the radiator support 18 extends in the vehicle longitudinal direction as shown in FIG. Present.

  A wheel house 25 is formed outside the front side member 9 in the vehicle width direction, and a suspension tower 26 to which a shock absorber constituting the suspension device 1 is connected is formed in the wheel house 25.

  According to the suspension device 1 of the present embodiment described above, the following operational effects can be obtained. That is, the vehicle of the reaction spring 6 when the vehicle front-rear impact force acting on the reaction spring 6 from the radiator support 18 via the connecting plate 7 exceeds a certain threshold at the time of a frontal collision or an offset frontal collision of the vehicle. It can be intentionally crushed at a predetermined portion in the front-rear direction, that is, at the shape suddenly changing portion 22.

  At the same time, by reducing the compressive strength in the vehicle front-rear direction of the predetermined portion, that is, the suddenly changing shape portion 22, smaller than the compressive strength of the torsion bar spring 5 in the vehicle front-rear direction, When the impact force in the vehicle front-rear direction acting on the reaction spring 6 from the support 18 via the connecting plate 7 exceeds a certain threshold value, the shape suddenly changing portion 22 of the reaction spring 6 is crushed before the torsion bar spring 5. be able to.

  Accordingly, the reaction spring 6 that has been previously crushed and deformed can be caused to interfere with the torsion bar spring 5 from the initial stage to the end stage at the time of frontal collision or offset frontal collision of the vehicle. Thereby, the torsion bar spring 5 can be bent based on the interference force of the reaction spring 6.

  Thereby, after the collision further proceeds from the initial stage toward the end stage, the vehicle front-rear direction gap, that is, the stroke A shown in FIG. 4 between the vehicle front end portion of the torsion bar spring 5 and the radiator support 18 is eliminated. An impact force in the vehicle front-rear direction is directly transmitted from the radiator support 18 to the torsion bar spring 5, and the torsion bar spring 5 is bent more greatly at the position where the torsion bar spring 5 is bent by the impact force. The spring 5 can absorb the impact force.

  In other words, the reaction spring 6 is first crushed by the impact force in the longitudinal direction of the vehicle, and then the torsion bar spring 5 is bent to absorb the impact force more effectively to secure the passenger compartment and protect the passenger. can do.

  In the suspension device 1 having such a configuration, the strength at the shape suddenly changing portion 22 and the shape suddenly changing portion 22 of the reaction spring 6 is appropriately set, so that the connecting plate is connected from the radiator support 18 to the vehicle at the time of frontal collision or offset frontal collision. When the impact force in the vehicle front-rear direction acting on the reaction tube 6 via 7 exceeds a certain threshold value, the energy absorption amount and deformation mode for the impact force can be set to desired values.

  That is, the sum of the energy absorption amount of the front side member 9 and the energy absorption amount of the reaction tube 6 and the torsion bar spring 5 is the energy absorption amount of the entire vehicle, and therefore the energy absorption amount of the entire vehicle can be increased. .

  At the same time, the reaction spring 6 is crushed at a predetermined place where the reaction spring 6 can be set in advance, that is, the shape sudden change portion 22, and the torsion bar spring 5 is also bent near the shape sudden change portion 22 of the reaction spring 6, that is, the predetermined portion. Therefore, the reaction spring 6 after being crushed and the torsion bar spring 5 after being bent are prevented from interfering with the tire constituting the wheel, the shock absorber constituting the suspension device 1 and other in-vehicle devices. be able to.

  Thereby, even after the impact force is absorbed by the reaction spring 6 and the torsion bar spring 5, the reaction spring 6 and the torsion bar spring 5 to other in-vehicle devices are prevented from interfering with each other. Detailed consideration can be realized.

  In addition, the shape sudden change portion 22 is appropriately changed so that the deformation mode of the torsion bar spring 5 and the reaction spring 6 is in the desired order and manner from the initial stage to the end stage at the time of frontal collision or offset frontal collision of the vehicle. As a result, the degree of freedom in designing the deformation mode can be increased.

  Further, by providing a front bumper reinforcement 23 in front of the front side member 9 and a sub front bumper reinforcement 24 in front of the connecting plate 7, an impact when the front bumper reinforcement 23 mainly collides with a building or a vehicle. The force is transmitted to the front side member 9, and when the collision target is a pedestrian, the impact force is transmitted to the sub-front bumper reinforcement 24. As a result, the performance of protecting the pedestrian can be enhanced.

  In addition, by providing the front bumper reinforcement 23 and the sub-front bumper reinforcement 24 offset in the vertical direction, the area in contact with the pedestrian can be increased, and the impact given to the pedestrian can be reduced.

  Further, in such a suspension device 1, the use of a coil spring can be avoided, so that the height of the suspension tower 26, which is a portion for connecting the shock absorber on the body side by reducing the vertical dimension of the suspension device 1. , And a sufficient vertical clearance between the hood (not shown) of the vehicle and the suspension tower 26 can be secured, and the pedestrian protection performance can be enhanced.

  In addition, the normal coil spring usually has a configuration in which a cylindrical steel material is wound in the same direction on the right and left sides of the vehicle, and the left and right suspension devices of the vehicle bounce in the same phase, In the case of rebound, that is, due to nose dive or tail lift, the component force in the vehicle width direction of the reaction force accompanying the bound rebound of the coil spring cannot be canceled between the left side and the right side, causing the vehicle flow. Problem arises.

  For this reason, in order to solve this problem, it was necessary to use coil springs whose winding directions were opposite on the right side and the left side, which led to an increase in cost. By using the bar spring 5 and the reaction spring 6, such a problem of cost increase can be avoided.

  Further, by eliminating the coil spring, it is possible to reduce the size of the suspension tower 26, and to prevent a reduction in rigidity caused by installing the suspension tower 26 in the wheel house 25 in which the suspension tower is normally configured. Can do.

  Instead of the reaction spring 6, the second torsion elastic means is solid, the first torsion elastic means and the second torsion elastic means are both two torsion bar springs, and they are connected by gears. Although the second torsion elastic means is a reaction spring 6 having a cylindrical shape enclosing the first torsion elastic means, the following effects can be obtained.

  That is, if the second torsion elastic means is a solid-shaped torsion bar spring, in the solid-shaped torsion bar spring, if the shape suddenly changing portion 22 as shown in FIG. 4 is provided, the axis of the torsion bar spring It is necessary to reduce the outer diameter of a part of the direction, and in order to make the torsional elastic force accompanying the swing of the lower arm 2 in accordance with the specifications required for the suspension device 1, It is necessary to generate the necessary torsional elastic force.

  That is, it is necessary to set the outer diameter of the portion other than the suddenly changing portion 22 of the torsion bar spring which is not reduced in outer diameter to an unnecessarily large outer diameter than the torsional elastic force required in the specifications. As a result, an increase in external dimensions and an increase in volume and weight are caused, resulting in waste in design.

  However, if the second torsional elastic means is a cylindrical reaction spring 6 as in the present embodiment, the shape suddenly changing portion 22 is, for example, a groove extending in the radial direction on the outer peripheral surface of the cylindrical reaction spring 6. Well, by providing the circumferential groove in the cylindrical material, the torsional elastic force in the shape sudden change portion 22 and the other portions compared to providing the shape sudden change portion 22 in the solid torsion bar spring. It is possible to prevent an extreme difference from occurring in the torsional elastic force.

  That is, because the shape in the cross section perpendicular to the central axis of the reaction spring 6 is an annular shape that is separated from the central axis by the same distance in the circumferential direction, the secondary moment of the cross section has the shape suddenly changing portion 22 and the others. In addition to the fact that the ratio that differs from the first part is smaller than the other, the ratio that differs by means such as adjusting the thickness of the shape sudden change part 22 can be appropriately suppressed. It is possible to avoid the necessity of giving the part more strength than necessary, and it is possible to prevent wasteful increase in volume and weight as a torsion bar spring, resulting in design waste.

  Furthermore, providing the circumferential groove in the cylindrical material can be easily realized by using press forming such as cold rolling or hot rolling, so the shape suddenly changing portion 22 is formed on the solid torsion bar spring. Compared to the provision of the first torsional elastic means, it is easier to configure, and it is possible to more easily realize the crushing by the impact force before the first torsional elastic means.

  Furthermore, the cross-sectional shape perpendicular to the vehicle longitudinal direction of the connecting plate 7 is a U-shape, and the torsional elasticity centered on the vehicle longitudinal direction is made smaller than the compression rigidity in the vehicle longitudinal direction, so that at the time of a frontal collision of the vehicle or In the event of an offset frontal collision, the compressive rigidity in the vehicle longitudinal direction of the connecting plate 7 can be increased, so that the impact force in the vehicle longitudinal direction is more efficiently transmitted from the radiator support 18 to the reaction spring 6 via the connecting plate 7. can do.

  At the same time, at the initial stage of the collision, a front-rear direction clearance between the vehicle front end portion of the torsion bar spring 5 and the radiator support 18, that is, a stroke A shown in FIG. By not transmitting the impact force in the direction, the reaction spring 6 can be more reliably crushed before the torsion bar spring 5.

  Further, since the torsional elasticity of the connecting plate 7 can be reduced, the front side member 9 in which the lower arm 2 constitutes the chassis is formed by connecting the vehicle front end portion of the reaction spring 6 to the radiator support 18 by the connecting plate 7. By swinging with respect to the torsion bar spring 5 and the reaction spring 6, it is possible to avoid the connecting plate 7 from affecting the relationship between the torsional elastic force generated by the torsion bar spring 5 and the reaction spring 6, that is, the spring constant, as much as possible.

  Here, when connecting the connecting plate 7 to the reaction spring 6 and connecting the connecting plate bolt 19 and the nut 20 in a plurality of positions in parallel in the vehicle front-rear direction, the connecting plate 7 is connected to the reaction spring 6. It can be avoided as much as possible that the connecting plate 7 restrains the circumferential displacement of the reaction spring 6.

  Also by this, the lower arm 2 swings with respect to the front side member 9 constituting the chassis, so that the torsional elastic force generated by the torsion bar spring 5 and the reaction spring 6 and the swinging of the lower arm 2 with respect to the front side member 9 are reduced. It can be avoided as much as possible that the connecting plate 7 influences the relationship, that is, the spring constant.

  In the suspension device 1 described above, as a specific means for making the torsional elasticity of the connecting plate 7 centered in the vehicle longitudinal direction smaller than the compression rigidity in the vehicle longitudinal direction, a cross-sectional shape perpendicular to the vehicle longitudinal direction is used. In addition to the shape of the letter, the following means can be used. In other words, the connecting plate 7 may be a flat plate, and a bead-shaped rib extending in the vehicle longitudinal direction may be provided at the center in the vehicle width direction. The material constituting the connecting plate 7 has a large compression rigidity in the vehicle longitudinal direction and is As a material having anisotropy with a small torsional rigidity, an appropriate means such as a simple flat plate shape can be selected.

  Furthermore, in the suspension device 1 of the present embodiment, the lower arm 2 is connected to the front side member 9 via the suspension member 8 at two connection points, that is, the bush 3 and the bush 4. The rear end portion of the vehicle is joined to the portion constituting the connecting point of the knuckle on the rear side of the vehicle, that is, the outer cylindrical portion 2c shown in FIG.

  At the same time, in the suspension device 1 of the present embodiment, the portion constituting the connecting point on the vehicle front side of the lower arm 2 is the hollow cylindrical portion whose axis is the vehicle longitudinal direction, that is, the inner portion of the outer cylindrical portion 2a shown in FIG. It has a hollow bolt nut 11 located on the circumferential side, and a torsion bar spring 5 is inserted into a hollow cylindrical portion formed by the hollow bolt nut 11.

  According to these, the length that the torsion bar spring 5 protrudes forward of the vehicle with respect to the lower arm 2 is the distance between the two connecting points of the lower arm 2 in the longitudinal direction of the vehicle, that is, the bush 3 and the bush Therefore, the size of the suspension device 1 in the vehicle longitudinal direction can be made as small as possible. Thereby, providing the torsion bar spring 5 can prevent the vehicle interior space and the engine compartment space of the vehicle from being restricted.

  Further, when the two connecting points of the lower arm 2 to the suspension member 8 are constituted by the well-known bushes 3 and 4, the center axis lines of the two bushes 3 and the bush 4 are made to coincide with each other so that the front side member of the lower arm 2 is matched. The swing with respect to 9 can be made smoother.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

  For example, in the embodiment described above, the lower arm 2 is a so-called A-arm, but other shapes can be used as long as the rigidity for supporting the knuckle can be ensured. It is also possible.

  In the above-described embodiments, the suspension device 1 is of the double wishbone type, but the type of the suspension device 1 is not particularly limited, and is of multi-link type, strut type, trailing arm type. Either may be sufficient. In any type of suspension device, the torsion bar spring 5 may be connected at the connection point on the vehicle body side of the arm or link connecting the knuckle and the vehicle body side.

  For example, as shown in FIG. 6, when the suspension device 1 is a multi-link type and there are two I-arms corresponding to the connecting means, the inside of the outer cylindrical portion 2Aa of the I-arm 2A located in front of the vehicle A hollow bolt nut 11 similar to that shown in FIG. 1 is screwed on the circumferential side, a torsion bar spring 5 is inserted into the hollow bolt nut 11, and the outer cylindrical portion 2Bc of the I arm 2B located at the rear of the vehicle. The suspension device 1 is configured by fitting the clasp 15 and fitting the torsion bar spring 5 to the clasp 15 by serration.

  In this case, two ball joints are required: a ball joint B / J1 for connecting the knuckle and the I arm 2A, and a ball joint B / J2 for connecting the knuckle and the I arm 2B.

  Note that the torsion bar spring may be connected to the upper arm or the upper side link as the upper arm of the so-called double wishbone type suspension device or the upper side link of the multi-link type suspension device. Conceivable.

  However, in this case, since the upper arm and the link on the upper side are necessarily positioned above the lower arm, when the torsion bar spring is extended in the vehicle front-rear direction, the vehicle interior space and the engine compartment space The restriction on the torsion is increased, and the advantage of using the torsion bar spring is reduced.

  For this reason, as shown in the above-described embodiments, it is preferable to use the lower arm 2 as the connecting means in order to secure as large a vehicle interior space as possible. Further, since it is difficult for a passenger car to secure the elements constituting the chassis at a position corresponding to the upper arm in the front portion of the vehicle, it is preferable that the connecting means is a lower arm as shown in the embodiment.

  The present invention relates to a suspension device suitable for being applied mainly to a front suspension device of a vehicle, and has a function of absorbing impact force in the longitudinal direction of the vehicle with a relatively simple configuration and minor changes. Since it is possible to realize detailed consideration for other in-vehicle devices after absorption, it is useful in enhancing safety by applying to various vehicles such as ordinary passenger cars, trucks, buses and the like.

It is a mimetic diagram showing one embodiment of a suspension device concerning the present invention. 1 is a schematic cross-sectional view showing an embodiment of a suspension device according to the present invention. 1 is a schematic cross-sectional view showing an embodiment of a suspension device according to the present invention. 1 is a schematic cross-sectional view showing an embodiment of a suspension device according to the present invention. 1 is a schematic perspective view showing a structure of a chassis to which an embodiment of a suspension device according to the present invention is applied. It is a mimetic diagram showing one embodiment of a suspension device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Suspension apparatus 2 Lower arm 2a Outer cylindrical part 2b Inner cylindrical part 2c Outer cylindrical part 2d Inner cylindrical part 3 Bush 4 Bush 5 Torsion bar spring 6 Reaction spring 7 Connecting plate 8 Suspension member 9 Front side member 10 Lower arm bracket 11 Hollow bolt nut 12 Nut 13 Lower arm bracket 14 Bush bolt 15 Clasp 16 Reaction spring bolt 17 Nut 18 Radiator support 19 Connecting plate bolt 20 Nut 21 Radiator support bolt 22 Shape sudden change 23 Front bumper reinforcement 24 Subfront bumper reinforcement 25 Wheel house 26 Suspension tower

Claims (8)

  Support means for rotatably supporting the wheels, connection means for swingably connecting the support means to a vehicle longitudinal member constituting the chassis, and a first twist joined to the connection means and extending forward of the vehicle Elastic means and second torsion elastic means joined to the vehicle front-rear direction member joined to the vehicle front end of the first torsion elastic means, and the second torsion elastic means A coupling member that has a form of enclosing the first torsional elastic means and connects a vehicle front end portion of the second torsional elastic means and a vehicle width direction member constituting the vehicle front end portion of the chassis; Suspension device characterized by this.   2. The suspension device according to claim 1, wherein a compressive strength in a vehicle longitudinal direction at a predetermined location of the second torsional elastic means is made smaller than a compressive strength in the vehicle longitudinal direction other than the predetermined location.   The suspension device according to claim 2, wherein the compressive strength in the vehicle front-rear direction at the predetermined location is made smaller than the compressive strength in the vehicle front-rear direction of the first torsional elastic means.   The suspension device according to claim 3, wherein the torsional elasticity of the coupling member around the vehicle longitudinal direction is made smaller than the compression rigidity in the vehicle longitudinal direction.   The suspension device according to claim 4, wherein a plurality of joint portions of the coupling member with the second torsional elastic means are provided in the vehicle front-rear direction.   The suspension device according to claim 5, wherein a cross-sectional shape of the coupling member perpendicular to the vehicle front-rear direction is a U-shape.   The connecting means is connected to the vehicle longitudinal member at two connecting points, and the vehicle rear end of the first torsional elastic means is a portion constituting the vehicle rear side connecting point of the support means. The suspension device according to any one of claims 1 to 6, wherein the suspension device is joined.   A portion constituting a connecting point on the vehicle front side of the connecting means has a hollow cylindrical portion with the vehicle longitudinal direction as an axis, and the first torsion elastic means is inserted into the hollow cylindrical portion. The suspension device according to claim 7.