JP2008173991A - Suspension device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device of a vehicle capable of providing a driver with bodily steering feeling even when the vehicle is in a turning state. <P>SOLUTION: When the vehicle is in the turning state by a steering operation of a steering mechanism 10, rotation torques around right and left king pin shafts are generated according to relative relations of the right-left king pin shafts KP supplied to a steering mechanism and spring reaction force lines of right and left coil springs 22r and 22l supplied to the suspension mechanism 20. In addition, with an adjusting means AJ, for at least one of wheels, the suspension mechanism 20 is adjusted so that a rotation torque works on a wheel of rotation outside in a toe-out increase direction and a rotation torque works on a wheel of rotation inside in a toe-in increase direction by a spring reaction force of the coil spring while the vehicle is in the turning state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle suspension device, and more particularly to a vehicle suspension device that generates rotational torque about a kingpin axis when the vehicle is in a turning state.

  Various suspension mechanisms are known as suspension systems for vehicles, but since the suspension mechanism related to the steering system supports the left and right wheels in front of the vehicle as steering wheels, coils that are generally arranged on the left and right in front of the vehicle A spring and left and right upper seats and lower seats for supporting these are provided. Further, the left and right wheels in front of the vehicle are connected to the steering mechanism as steering wheels, and a kingpin shaft (or simply kingpin) that is a geometrical central axis that rotates around the steering wheel is provided to the steering mechanism. Used for suspension mechanism. That is, the main component of the steering force is the torque around the kingpin axis, and the kingpin tilt angle, which is the angle with respect to the vertical line of the kingpin axis, is one of the factors representing the performance of the suspension. Served for both. In other words, in the vehicle suspension system, when various measures are taken with the kingpin shaft as a reference, it is necessary to examine the suspension system as a device that includes a part of the steering mechanism.

  In relation to the above suspension mechanism, Patent Document 1 discloses a method for compensating side pull, and Patent Document 2 discloses a method for adjusting a rotational moment by a coil spring. First, Patent Document 1 states that “in order to correct a side pull in a specific direction and, if appropriate, a correction action incorporated in the initial design of the vehicle to correct a side pull in the opposite direction. "To propose a solution for vehicles with a MacPherson steering axle", the "strut (1) is offset and / or tilted with respect to the axis of the shock absorber rod (3) It has a support axis (4) for the spring (5) on the lower spring seat (6), this arrangement allows the thrust (vector F) axis of the spring (5) to be a distance (d) from the pivot axis (DB). Spaced apart and generating torque about the pivot axis (DB), the action of this torque and the corresponding torque in the opposing struts It is can be "effect wherein to compensate the tendency of the vehicle to skid from a straight course with action.

  Further, in Patent Document 2, an object is to “use a rotational moment acting on a wheel holding member based on the elastic force of a coil spring”, and “hold the left wheel and the right wheel together with the wheel. In a suspension device including each coil spring provided between a wheel holding member rotatable around a turning shaft and a vehicle body side member, a coil spring corresponding to each of the left wheel and the right wheel is provided with a coil spring. This is solved by causing the wheel holding members to generate rotational moments around the turning shaft as the wheel is compressed, and the directions of the rotational moments to be opposite to each other on the left and right.

JP-T-2003-521411 Japanese Patent Laid-Open No. 9-300932

  The above-mentioned Patent Documents 1 and 2 do not refer to the relationship with the steering mechanism and do not take into consideration the turning state of the vehicle. However, like a general suspension device, the vehicle is controlled by the steering operation of the steering mechanism. Rotating torque around the left and right kingpin shafts according to the relative relationship between the left and right kingpin shafts used for the steering mechanism and the spring reaction force lines of the left and right coil springs used for the suspension mechanism Is configured to occur.

  With regard to the above suspension device, in the device described in Patent Document 1, the rotational torques of the left and right wheels at the time of turning of the vehicle are canceled out, resulting in a steering feeling unresponsive to the driver. Further, in the device described in Patent Document 2, when the vehicle is in a turning state, a rotational torque is generated in a direction in which the wheels are steered in the toe-in direction. The steering return torque transmitted to the vehicle is in the opposite phase, resulting in a steering feeling unresponsive to the driver.

  Accordingly, an object of the present invention is to provide a vehicle suspension device that can provide a steering feeling that is responsive to the driver even when the vehicle is in a turning state.

  In order to solve the above-described problems, according to the present invention, as described in claim 1, when the vehicle is in a turning state by a steering operation of the steering mechanism of the vehicle, In a vehicle suspension apparatus configured to generate rotational torque about the left and right kingpin shafts according to a relative relationship with spring reaction force lines of left and right coil springs provided for a suspension mechanism, With respect to at least one of the wheels, a rotational reaction force is exerted on a wheel outside the turning of the vehicle in a toe-out increasing direction by a spring reaction force of the coil spring in the turning state of the vehicle, and the inside of the turning of the vehicle Adjusting means for adjusting the suspension mechanism so that rotational torque acts on the wheels of the vehicle in the toe-in increasing direction It is obtained by a comprise.

  In the suspension apparatus, as described in claim 2, the suspension mechanism supports a shock absorber disposed in the vehicle and the coil spring so as to surround the shock absorber, and fixes the suspension to a vehicle body of the vehicle. An upper seat is provided, and the adjusting means may be set so that the central axis of the upper seat is offset to the rear side of the vehicle with respect to the central axis of the shock absorber. Alternatively, as described in claim 3, the suspension mechanism includes a shock absorber disposed in the vehicle, and a lower seat that supports the coil spring so as to surround the shock absorber and is fixed to the shock absorber. The adjusting means may be set so that the center axis of the lower seat is offset to the front side of the vehicle with respect to the center axis of the shock absorber.

  According to a fourth aspect of the present invention, the suspension mechanism includes a shock absorber disposed in the vehicle, an upper seat that supports the coil spring so as to surround the shock absorber, and is fixed to a vehicle body of the vehicle. A lower seat fixed to the shock absorber is provided, and the adjustment means may use a coil spring having a coil shaft curved on the rear side of the vehicle as the coil spring.

  Further, according to claim 5, the suspension mechanism includes a shock absorber disposed in the vehicle, an upper seat that supports the coil spring so as to surround the shock absorber, and is fixed to the vehicle body of the vehicle. The adjustment means may be arranged such that the coil spring is in contact with the upper seat on the front side of the vehicle and a gap is formed on the rear side of the vehicle. Alternatively, as described in claim 6, the suspension mechanism includes a shock absorber disposed in the vehicle, and a lower seat that supports the coil spring so as to surround the shock absorber and is fixed to the shock absorber. The adjusting means may be arranged such that the coil spring is in contact with the lower seat on the front side of the vehicle so that a gap is formed on the rear side of the vehicle.

  Further, in each of the suspension devices, as described in claim 7, the left and right coil springs may be set to be reversely wound with each other.

  Since this invention is comprised as mentioned above, there exist the following effects. That is, in the suspension device according to the present invention, the adjusting means causes a rotational torque to act on the outer wheel of the turning in the toe-out increasing direction by the spring reaction force of the coil spring in the turning state of the vehicle. On the other hand, the torque is adjusted so that the rotational torque acts in the toe-in increasing direction. Therefore, when the vehicle turns, the rotational torque increases or decreases in the direction opposite to the turning direction with respect to the wheels as the amount of increase or decrease of the rotational torque due to the spring reaction force of the coil spring. Thus, the steering feeling during turning of the vehicle can be adjusted appropriately.

  Further, if the suspension mechanism and the adjusting means are configured as described in claims 2 to 5, the steering feeling during turning of the vehicle can be appropriately adjusted with a simple configuration.

  Further, by configuring as described in claim 7, it is possible to reliably and more appropriately adjust the steering feeling when the vehicle turns.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The suspension device according to one embodiment of the present invention has the appearance shown in FIGS. 2 and 3, and FIG. 1 shows a part of the steering mechanism and suspension mechanism related to one wheel. First, as shown in FIGS. 1 and 2, in the steering mechanism 10, a steering wheel 11 is connected to a gear box 13 via a steering column 12, and tie rods 14l and 14r and knuckle are respectively provided on the left and right sides of the gear box 13. Knuckles 16l and 16r are connected via linkages of the arms 151 and 15r, and tires LT and RT are pivotally supported by the knuckles 16l and 16r. The knuckles 16l and 16r are swingably supported by the lower arms 17l and 17r, respectively, and the lower arms 17l and 17r are swingably supported by the vehicle body.

  On the other hand, the suspension mechanism 20 of the present embodiment is a Max Pherson strut type, and coil springs 22l and 22r are disposed so as to surround shock absorbers 21l and 21r disposed on the left and right sides of the vehicle, respectively. . As shown in FIG. 3, cylindrical coil springs CC are used for the coil springs 22l and 22r of the present embodiment, and left and right upper seats 23l and 23r supported by a vehicle body (not shown) and a shock absorber 21l. And the lower seats 24l and 24r fixed to 21r, respectively, and are held in a compressed state. The shock absorbers 21l and 21r have upper ends supported by the vehicle body together with the upper sheets 23l and 23r, and lower ends fixed to the knuckles 16l and 16r, respectively.

  In the suspension device of the present embodiment, the kingpin shaft KP and the spring reaction force line SP are offset as shown in FIG. 1 as in the conventional suspension device. Further, regarding the support of the coil springs 22l and 22r. The relative positional relationship LR between the upper seats 23l and 23r and the coil springs 22l and 22r is set as shown in FIG. 3 (this will be described later as the first embodiment), or the lower seats 24l and 24r and the coil spring 22l. And 22r are set to the opposite relationship to the above. Alternatively, a coil spring having a special shape is disposed between the upper sheet and the lower sheet similar to the conventional one, and for example, a coil spring CS as shown in FIG. 9 is used (this will be described later as a second embodiment).

  Thus, the adjusting means AJ shown in FIG. 1 is constituted by these, the spring reaction force lines SP of the left and right coil springs 22l and 22r are appropriately adjusted, and finally the vehicle (not shown) is in a turning state. As the amount of compression (Ca) of the coil springs 22l and 22r increases and decreases, the amount of change (Tv) in rotational torque about the left and right kingpin shafts KP rotates the left and right wheels outwardly of the vehicle. To be adjusted. That is, for at least one of the wheels (tires LT or RT), rotational torque acts on the wheels on the outer side of the turn in the toe-out increasing direction by the spring reaction force of the coil spring 22l or 22r in the vehicle turning state, and Adjustment is made so that rotational torque acts on the wheels in the toe-in increasing direction.

  For example, when a vehicle (not shown) is turning rightward as indicated by a clockwise white arrow in FIG. 2, the left coil spring 22l is compressed by the load movement, but the right coil spring is compressed. 22r expands. For this reason, in the apparatus described in Patent Document 2, for example, the steering return torque transmitted to the driver's hand is opposite in phase with respect to the steering force in the turning direction, and the steering feeling is unresponsive. On the other hand, in the present invention, for example, it is configured as in a first embodiment or a second embodiment to be described later, and at least one wheel (tire LT or RT), a wheel outside the turn when the vehicle turns. In contrast, the rotational torque acts in the toe-out increasing direction, and the rotational torque acts on the wheels on the inside of the turn in the toe-in increasing direction. Therefore, as shown by the counterclockwise arrows in FIG. Force torque is applied. As a result, the steering return torque Tc is applied to the steering wheel 11 as shown by the counterclockwise arrow in FIG. 2, so that the steering feeling when the vehicle turns is appropriately adjusted. Thus, when the vehicle turns, a rotational torque acts on the tires LT and RT in the direction opposite to the turning direction as an increase / decrease amount of torque due to the spring reaction force of the coil springs 22l and 22r on the left and right sides of the vehicle. Therefore, the driver can feel an appropriate response (steering feeling).

  FIG. 3 shows a first embodiment of the present invention, in which the central axes of the left and right upper seats 23l and 23r constituting the suspension mechanism 20 are both relative to the central axes of the left and right shock absorbers 21l and 21r. Is set so as to be offset by a distance (Yu) on the rear side, and this Yu is referred to as an upper sheet offset amount. Instead of this configuration, the center axis of the lower seats 24l and 24r may be set to be offset to the front side of the vehicle with respect to the center axis of the shock absorbers 21l and 21r, or may be set to only one wheel. .

  As shown in FIG. 3, due to the offset of the central axes of the upper sheets 231 and 23r, the rotational torque around the left and right kingpin shafts KP is increased according to the increase in the compression amount (referred to as Ca) of the coil springs 22l and 22r. The amount of change (referred to as Tv) is adjusted to decrease, which will be described below with reference to FIGS. First, FIG. 4 is used for the definition of the rotational torque (represented by Mkp) about the kingpin axis KP. The z axis is the central axis of the shock absorber 21l (or 21r), and the x axis is the vehicle width direction ( In the case of the right wheel, the arrow direction indicates outward), the y-axis is the vehicle front-rear direction (arrow direction indicates front), the two-dot chain line indicates the kingpin axis KP, and the origin (0) is the kingpin axis KP And the central axis (z-axis) of the shock absorber. Therefore, the kingpin axis KP is in the xz plane and forms an angle θ with respect to the central axis (z axis) of the shock absorber.

In FIG. 4, the forces input to the shock absorbers 21l and 21r via the bearings are Fx, Fy and Fz, and the moments (torque) are Mx, My and Mz (where Mz is zero). Of these five components, only the moment Mx affects the rotational torque Mkp around the kingpin axis KP, and is expressed by the following equation.
Mkp = Mx · cos {(π / 2) −θ} = Mx · sin θ
Here, there is a relationship of Mx = Yu · Fz, and when the relative angle θ between the kingpin axis KP and the z-axis is given, the rotational torque Mkp around the kingpin axis KP is expressed by Mkp = Yu · Fz · sin θ. Thus, when generating the moment Mx as shown in FIG. 4, Yu is negative and Mkp is also negative. That is, when the direction of Mkp is negative, torque that rotates the tire RT to the right is generated.

  According to the first embodiment shown in FIG. 3, the amount of change ΔMkp (corresponding to the above-mentioned Tv) of the rotational torque Mkp generated as the coil springs 22l and 22r are compressed is as shown in FIGS. Further, it is proportional to the upper sheet offset amount (the offset amount Yu of the upper sheets 231 and 23r). In this case, when the amount of change ΔMkp generated along with the compression of the coil springs 22l and 22r is reduced, the response to the driver is improved, so the upper seat offset amount may be set on the rear side of the vehicle. FIG. 5 shows the experimental results when the left-hand coil spring (L) and the right-hand coil spring (R) are used for different vehicle types (A and B) with respect to the vehicle left wheel (L). In FIG. 5, for example, LAL indicates a case where a left-handed coil spring is used for the left wheel of the vehicle type A. FIG. 6 shows the experimental results when the left-handed coil spring (L) and the right-handed coil spring (R) are used for different vehicle types (A and B) with respect to the right wheel (R) of the vehicle. In FIG. 6, for example, RAR indicates a case where a right-handed coil spring is used for the right wheel of the vehicle type A.

  Furthermore, if the winding directions of the left and right coil springs 22l and 22r are opposite to each other, the amount of change ΔMkp can be further reduced, which is apparent by comparing FIG. 7 and FIG. That is, FIG. 7 shows the experimental results of a general configuration in which right-handed coil springs are mounted on the left and right wheels, and [LAR + RAR] uses a right-handed coil spring on the left wheel for vehicle type A. When the right-handed coil spring is used for the right-hand wheel, the total change amount ΔMkp represents the change with respect to the upper seat offset amount, and [LBR + RBR] is a right-handed coil spring for the left-hand wheel for the vehicle type B. The change with respect to the upper sheet offset amount of the total change amount ΔMkp when a right-handed coil spring is used for the right wheel is shown. On the other hand, FIG. 8 shows the experimental results when the coil springs reversely wound with each other are attached to the left and right wheels, and the total change amount ΔMkp is further reduced. Here, [LAR + RAL] is related to the vehicle type A with respect to the upper seat offset amount of the total change amount ΔMkp when a right-handed coil spring is used for the left wheel and a left-handed coil spring is used for the right wheel. [LBL + RAR] represents the change in the upper seat offset amount for the vehicle type B when the left-handed coil spring is used for the left wheel and the right-handed coil spring is used for the right wheel. Represents the change to.

  FIG. 9 shows a second embodiment of the present invention, in which a coil spring CS having a special shape is used as the coil springs 22l and 22r constituting the suspension mechanism 20. FIG. Specifically, as shown in FIG. 10, the coil spring CS having a curved body having a coil shaft curved toward the rear side of the vehicle is used, and the relative angle between the upper seat and the seat surface is shown. Rotating by changing the direction of the bend (expressed by θu, the arrow direction shown in FIG. 10 is the positive direction) and the body bending direction (the direction in which the vertical line shown in FIG. 10 moves from the one-dot chain line to the solid line is the positive direction) The change amount ΔMkp of the torque Mkp can be adjusted.

  For example, in FIG. 11, when the relative angle θu between the upper seat and the seating surface is large (for example, in the case of + 10 °), the rotational torque Mkp decreases with compression (when the spring height decreases), and the relative angle θu decreases. (For example, in the case of −5 °), the rotational torque Mkp increases with compression. Note that the conventional device exhibits a characteristic in which the relative angle θu is 0 °. Further, as shown in FIG. 12 showing the experimental results of the vehicle type a and the vehicle type b, when the coil spring CS is compressed (for example, from the mounting height +25 mm to the mounting height −25 mm), it changes as the relative angle θu increases. The quantity ΔMkp decreases.

  In addition, instead of the configuration using the coil spring CS of FIG. 9, the coil spring CC may be arranged so as to contact the upper seat on the front side of the vehicle so that a gap is formed on the rear side of the vehicle. The effect of can be obtained. Or it is the same as arrange | positioning so that the coil spring CC may contact | abut on the front side of a vehicle with respect to a lower seat, and a space | gap may be formed in the back side of a vehicle.

  As described above, according to each of the above embodiments, when turning the vehicle, the amount of increase or decrease in rotational torque due to the spring reaction force of the coil springs 22l and 22r on the left and right of the vehicle is opposite to the turning direction with respect to the tires LT and RT. Rotational torque acts in the direction of. Thus, as shown in FIG. 13 in comparison with the conventional apparatus and the steering torque according to the present invention, according to the present invention, a large steering torque is applied at the time of turning of the vehicle. Steering feeling is good.

It is a perspective view which shows the outline | summary of a structure of the suspension apparatus which concerns on one Embodiment of this invention. It is a top view which shows a part of suspension system which concerns on one Embodiment of this invention. It is a perspective view showing a part of suspension system concerning a 1st embodiment of the present invention. FIG. 3 is a three-dimensional diagram illustrating rotational torque about a kingpin axis in the first embodiment of the present invention. It is a graph which shows an example of the experimental result about the wheel on the left side of vehicles in a 1st embodiment of the present invention. It is a graph which shows an example of the experimental result about the wheel on the right side of vehicles in a 1st embodiment of the present invention. It is a graph which shows an example of an experimental result when the right-handed coil spring is mounted on the left and right wheels in the first embodiment of the present invention. It is a graph which shows an example of an experimental result when a mutually reversely wound coil spring is mounted | worn with respect to the left-right wheel in the 1st Embodiment of this invention. It is a perspective view which shows a part of suspension system concerning the 2nd Embodiment of this invention. It is explanatory drawing which shows the adjustment method of the rotational torque change amount by the coil spring with which it uses for the 2nd Embodiment of this invention. It is a graph which shows an example of the experimental result in the 2nd Embodiment of this invention. It is a graph which shows the other example of the experimental result in the 2nd Embodiment of this invention. It is a graph which shows the difference of the effect of the suspension apparatus which concerns on this invention, and a conventional apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Steering mechanism 11 Steering wheel 12 Steering column 13 Gear box 14l, 14r Tie rod 15l, 15r Knuckle arm 16l, 16r Knuckle 17l, 176r Lower arm 20 Suspension mechanism 22l, 22r Coil spring 23l, 23r Upper seat KP Kingpin shaft LT, RT Tire

Claims (7)

  Depending on the relative relationship between the left and right kingpin shafts provided to the steering mechanism and the spring reaction force lines of the left and right coil springs provided to the vehicle suspension mechanism when the vehicle is in a turning state by the steering operation of the vehicle steering mechanism. In the vehicle suspension apparatus configured to generate rotational torque about the left and right kingpin shafts, the coil springs in the turning state of the vehicle are related to at least one of the left and right wheels of the vehicle. The suspension reaction is adjusted so that the rotational torque acts on the outer wheels of the vehicle in the toe-out increasing direction and the rotational torque acts on the inner wheels of the vehicle in the toe-in increasing direction by the spring reaction force. A vehicle suspension device comprising adjusting means for performing   The suspension mechanism includes a shock absorber disposed in the vehicle, and an upper seat that supports the coil spring so as to surround the shock absorber and is fixed to a vehicle body of the vehicle, and the adjusting means includes the upper seat The vehicle suspension system according to claim 1, wherein the central axis of the vehicle is set to be offset toward the rear side of the vehicle with respect to the central axis of the shock absorber.   The suspension mechanism includes a shock absorber disposed in the vehicle, and a lower seat that supports the coil spring so as to surround the shock absorber and is fixed to the shock absorber, and the adjusting means includes a central shaft of the lower seat 2. The vehicle suspension device according to claim 1, wherein the vehicle suspension is set to be offset toward a front side of the vehicle with respect to a central axis of the shock absorber.   The suspension mechanism includes a shock absorber disposed in the vehicle, an upper seat that supports the coil spring so as to surround the shock absorber, and is fixed to a vehicle body of the vehicle, and a lower seat that is fixed to the shock absorber. The suspension device for a vehicle according to claim 1, wherein the adjustment means uses a coil spring having a coil shaft curved toward the rear side of the vehicle as the coil spring.   The suspension mechanism includes a shock absorber disposed in the vehicle, and an upper seat that supports the coil spring so as to surround the shock absorber and is fixed to a vehicle body of the vehicle, and the adjustment means includes the coil spring The vehicle suspension device according to claim 1, wherein the vehicle suspension is disposed so as to abut against the upper seat on the front side of the vehicle so that a gap is formed on the rear side of the vehicle.   The suspension mechanism includes a shock absorber disposed in the vehicle, a lower seat that supports the coil spring so as to surround the shock absorber, and is fixed to the shock absorber, and the adjusting means includes the coil spring, 2. The vehicle suspension device according to claim 1, wherein the vehicle suspension device is disposed so as to abut against the lower seat on the front side of the vehicle and to form a gap on the rear side of the vehicle.   The vehicle suspension apparatus according to any one of claims 1 to 6, wherein the left and right coil springs are reversely wound with each other.

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