JP2009113692A - Rear axle adjustment mechanism for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rear axle adjustment mechanism capable of surely and smoothly adjusting relative position of a rear axle of a vehicle. <P>SOLUTION: This rear axle adjustment mechanism for vehicle comprises a linked rigid axle suspension connecting a right and a left rear wheels of a vehicle with one axle 10 and having at least four links, and adjusts relative position of the axle to a vehicle body by displacing the axle relative to the vehicle body. An actuator 30 is fixed to the vehicle body, and connected to at least one link (a lower arm 13 or 14) of the four links. In response to the movement of the actuator in the back and forth direction of the link, relative position of the axle to the vehicle body is adjusted. Further, by arranging the actuators in right and left of the vehicle, they can be driven at the same time, and both output shafts are extended to set a wheel base in the extended state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rear axle adjustment mechanism of a vehicle, and more particularly to a vehicle equipped with a link type rigid axle suspension in which left and right wheels at the rear of the vehicle are connected by one axle and has at least four links. The present invention relates to a rear axle adjustment mechanism that adjusts the relative position of the axle behind the vehicle.

  As for the suspension of the vehicle, for example, as described in Non-Patent Document 1 below, a rigid axle suspension that connects the left and right wheels of the vehicle with a single axle, and an independent that the left and right wheels move independently It is divided into dent suspensions, and there are various types of suspensions. For example, the rigid axle suspension includes a parallel leaf suspension and a link suspension, and the former is used for trucks and the like. The latter is also known as a four-link type consisting of four links of a pair of upper arms and a pair of lower arms, and a five-link type consisting of five links plus a lateral rod. -It is used for vehicles called utility vehicles (hereinafter referred to as SUV vehicles).

  On the other hand, the following Patent Document 1 relates to a rear axle steering mechanism in a truck or the like: “A rear axle housing that supports rear wheels at both ends in the vehicle width direction is suspended on a vehicle body via a laminated leaf spring device. It has been proposed that the housing itself be rotated around the center of rotation on the center line in the longitudinal direction of the vehicle body (paragraph [0004] of Patent Document 1). Further, Patent Document 2 below provides “a rear wheel steering device that is durable and reliable and can stably steer rear wheels even in a truck or the like in which double tires are used for rear wheels”. (Paragraph [0007] of Patent Document 2) has been proposed.

  Further, the following Patent Document 3 states that “in a truck or the like in which a rigid rear axle housing is suspended on a chassis frame via a laminated leaf spring device, it is possible to improve steering stability during high-speed traveling, and The rear axle housing, which supports the rear wheels at both ends in the vehicle width direction, has a V-shaped upper part for the purpose of alleviating the shock at the time of passing through the seam and improving the riding comfort and reducing vibration noise. It is configured so that the rear wheels are steered when the vehicle is traveling at a high speed by being integrally rotated around the center of the ball joint at the apex of the radius slot. "(Patent Document 3 Summary) ing.

Japanese Patent Laid-Open No. 7-10029 Japanese Patent Laid-Open No. 5-105108 JP-A-6-171544 Kayaba Kogyo Co., Ltd. “Suspension of automobiles”, Sankai-do Co., Ltd., May 8, 1997, 8th edition, pages 13-22

  As described above, a rigid rigid axle suspension is effective for SUV-based vehicles with many opportunities for driving on rough roads, but a rear-wheel steering function (hereinafter referred to as a 4WS function) in a four-wheel steering system is also required. For this, as described in Patent Documents 1 to 3, it is conceivable to provide a rear axle steering mechanism.

  However, all of the devices described in Patent Documents 1 to 3 have a structure peculiar to a truck and are premised on leaf type suspensions. Therefore, they cannot be immediately applied to SUV type vehicles having link type suspensions. Absent. In addition, in the devices described in Patent Documents 1 to 3, it is necessary to add the V-shaped rod, push rod, and the like described in the Patent Document due to the suspension structure, and the number of parts to be added increases. Furthermore, in an SUV system vehicle, if the wheelbase can be extended and set in an extended state when traveling straight ahead, the running stability can be improved, and conversely, the vehicle can be turned back by contracting. However, this is not possible with the devices described in Patent Documents 1 to 3.

  Accordingly, an object of the present invention is to provide a rear axle adjustment mechanism that can reliably and smoothly adjust the relative position of the rear axle of the vehicle with respect to the vehicle body in the rear axle adjustment mechanism of the vehicle. It is another object of the present invention to make the wheel base extendable and improve the straight running stability and turning ability of the vehicle.

  In order to achieve the above object, according to the present invention, a linked rigid axle suspension having at least four links in which left and right wheels at the rear of a vehicle are connected by one axle is provided. A rear axle adjusting mechanism that is mounted on a vehicle and adjusts the relative position of the axle with respect to the vehicle body by displacing the axle with respect to the vehicle body, and is fixed to the vehicle body and at least one of the four links. And an actuator for driving the link in the front-rear direction of the vehicle, and adjusting the relative position of the axle with respect to the vehicle body according to the movement of the link in the front-rear direction by the actuator. Further, a lateral rod may be provided to constitute a 5-link type rigid axle suspension.

  In the rear axle adjustment mechanism, as described in claim 2, the vehicle body includes a pair of side rails arranged in parallel to the left and right of the vehicle and extending in the front-rear direction of the vehicle, The link type rigid axle suspension includes a pair of upper arms and a pair of lower arms arranged on the left and right sides of the vehicle and connected to the axle, and the actuator is supported by side rails on the left and right sides of the vehicle. It is good to set it as the structure connected with the front-end part of the lower arm of the right-and-left one side.

  Alternatively, in the rear axle adjustment mechanism, as described in claim 3, the vehicle body includes a pair of side rails arranged in parallel to the left and right of the vehicle and extending in the front-rear direction of the vehicle. The link type rigid axle suspension includes a pair of upper arms and a pair of lower arms arranged on the left and right sides of the vehicle and connected to the axle, and the actuator is supported by side rails on the left and right sides of the vehicle, respectively. It is good also as a structure connected with the front-end part of the lower arm of the both right and left sides of the said vehicle, respectively.

  Further, according to a fourth aspect of the present invention, there is provided a lever that is rotatably supported by the side rail and orthogonal to the side rail, and the actuator is rotatably supported at one end of the lever. In addition, the front end portion of the lower arm may be rotatably supported on the other end of the lever. The actuator may include an electric motor having an output shaft that moves in the front-rear direction of the vehicle by a rotation-linear conversion mechanism, and the output shaft of the electric motor may be connected to the front end portion of the lower arm. .

  In the rear axle adjustment mechanism, the actuator is configured to be supported on the outside of the vehicle with respect to the side rail as described in claim 5, or as described in claim 6, It is good also as a structure supported by the inner side of the said vehicle with respect to a rail, and also the structure supported below the said vehicle with respect to the said side rail as described in Claim 7.

  Since this invention is comprised as mentioned above, there exist the following effects. That is, in the rear axle adjusting mechanism configured as described in claim 1, the 4WS function is exhibited with respect to the wheel behind the vehicle, and the running stability and the emergency avoidance performance in the medium / high speed range can be improved. Moreover, the relative position (angle) with respect to the vehicle body is adjusted with respect to the rear axle of the vehicle used for the rigid axle suspension similar to the conventional one, so that the number of parts is greatly increased compared to the conventional device. With a simple configuration, it is possible to ensure stable running that is effective particularly for SUV vehicles that have many opportunities for running on rough roads.

  In particular, when configured as described in claim 2, it is possible to exhibit a 4WS function with respect to the rear wheels of the vehicle with a simple configuration in which an increase in the number of parts is minimized as compared with the conventional device and an actuator is attached. An inexpensive apparatus can be provided.

  Further, according to the third aspect of the present invention, in addition to the above-described effects, a wheel base extending function for extending both output shafts by simultaneously driving the left and right actuators is provided. As a result, when the vehicle is traveling at a medium to high speed, the wheel base can be extended and extended to improve the straight traveling stability of the vehicle. Thus, in addition to the 4WS function described above, the wheelbase extension function can also be exhibited. By combining these two functions, the low speed turning ability in the shortened state (or the original state), the middle speed range in the extended state, Driving stability and emergency avoidance performance due to the 4WS function can be improved.

  Furthermore, if the lever is provided as described in claim 4, the burden on the actuator can be reduced, so that the actuator can be made small and inexpensive. If the actuator is configured by an electric motor, the 4WS function and the wheelbase extension function can be easily and reliably exhibited.

  And if the said actuator is arrange | positioned as described in Claim 5, it can mount | wear with respect to the existing vehicle easily. Or if it arrange | positions like Claim 6, an actuator can be accommodated between parallel side rails and it will become compact. Furthermore, if it arrange | positions as described in Claim 7, even when there is no margin in the both sides of a side rail, an actuator can be suitably attached to a side rail.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a suspension system for a rear part of a vehicle equipped with a rear axle adjusting mechanism according to an embodiment of the present invention. The left and right wheels RR and RL on the rear side of the vehicle are connected by a single axle 10 and are linked rigidly. An axle suspension is configured. In the present embodiment, as shown by a two-dot chain line in FIG. 1, a pair of side rails 21 and 22 that are arranged in parallel to the left and right of the vehicle and extend in the front-rear direction of the vehicle are provided. As shown by solid lines in FIGS. 1 to 3, five links including a pair of upper arms 11 and 12, a pair of lower arms 13 and 14, and a lateral rod 15 disposed on the left and right of the vehicle and connected to the axle 10. Thus, a 5-link type rigid axle suspension is configured.

  As shown in FIG. 1, a pair of actuators 30 are supported by the left and right side rails 21 and 22, respectively, and are connected to the front end portions of the left and right lower arms 13 and 14, respectively. 2 and 3, the arrangement of each link is shown, and the actuator 30 is omitted. The actuators 30 arranged on the left and right sides of the vehicle have the same structure, and are configured to be enlarged as shown in FIGS. 4 and 5. Further, as shown as enlarged in FIGS. Via the front ends of the lower arms 13 and 14.

  4 and 5, the actuator 30 of the present embodiment includes an electric motor 31 so that the output shaft 32 moves in the vehicle front-rear direction (left-right direction in FIG. 4) by a rotation-linear conversion mechanism (not shown). Controlled. The electric motor 31 is rotatably supported by a bracket 36 via a bearing 35 at a support portion 34 opposite to the output shaft 32, and the bracket 36 is fixed to the side rail 21 (or 22 in FIG. 1). ing.

  On the other hand, a bearing 33 is fixed to the tip of the output shaft 32 of the electric motor 31, and the bearing 33 is interposed between a pair of arm portions 42 and 42 formed at one end of the lever 41 as shown in FIGS. The output shaft 32 and the lever 41 are supported so as to be able to rotate around a bolt 43 that passes through them. The lever 41 is inserted in a bracket 44 fixed to the side rail 21 (or 22), and is supported to be swingable around a pin 45 fixed to the bracket 44 by a nut 45x. The other end side of the lever 41 is rotatably supported by the front end portion of the lower arm 13 (or 14) via the pin 46, and the lever 41 and the lower arm 13 (or 14) are supported so as to be swingable with respect to each other. . Thus, in the present embodiment, the lever 41 swings around the pin 45 in accordance with the back and forth movement of the output shaft 32 of the electric motor 31, and the lower arm 13 (or in response to the swing of the lever 41). 14) is driven in the longitudinal direction of the vehicle.

  The operation of the rear axle adjusting mechanism having the above-described configuration will be described. When one output shaft 32 of the left and right actuators 30, 30 is extended (distance Lw in the longitudinal direction of the vehicle) and the other is shortened (or original state). The left and right lower arms 13 and 14 are driven in opposite directions. As a result, the entire rear axle including the wheels RR and RL and the axle 10 is swung, and the wheels RR and RL are steered, for example, as shown in FIG. Thus, the 4WS function can be exhibited with respect to the wheels RR and RL at the rear of the vehicle, and the running stability and the emergency avoidance performance in the medium / high speed range can be improved.

  On the other hand, when the output shafts 32 of the left and right actuators 30 and 30 are extended by the same distance, the left and right lower arms 13 and 14 move rearward of the vehicle. As a result, the entire rear axle including the wheels RR and RL and the axle 10 moves in parallel to the rear of the vehicle. For example, as shown in FIG. 9, the wheel base W is extended by approximately the extension distance (Lw) of the output shaft 32. . Thus, the wheelbase extension function can be exhibited and the straight running stability at high speeds can be improved. On the contrary, when the output shafts 32 of both the left and right actuators 30 and 30 are shortened by the same distance (or when they are shortened relative to the extended state by returning to the original state), the left and right lower arms 13 And 14 move forward of the vehicle. As a result, the entire rear axle including the wheels RR and RL and the axle 10 moves forward of the vehicle, and the wheel base W is shortened by a substantially shortened distance of the output shaft 32. Thus, in this case, it is possible to improve the turning and turning ability in the low speed range.

  As described above, according to the rear axle adjustment mechanism of the present embodiment, both the 4WS function and the wheelbase extension function can be exhibited. Therefore, by combining these functions, the low speed range due to the shortened state (or the original state) is achieved. Can be improved, the running stability in the medium and high speed range due to the extended state, and the emergency avoidance performance due to the 4WS function.

  On the other hand, in the case of a rear axle adjusting mechanism focusing only on the 4WS function, the actuator 30 shown in FIG. 1 is provided only on the side rail 21 (or 22) on the left and right side of the vehicle, and the lower arm 13 on the left and right side is provided. What is necessary is just to set it as the structure connected with the front-end part of (or 14). As a result, when the output shaft 32 of the actuator 30 is extended, the left and right lower arms 13 and 14 are driven in opposite directions. As a result, the entire rear axle including the wheels RR and RL and the axle 10 is swung, and the wheels RR and RL are steered. Thus, the 4WS function can be exhibited with respect to the wheels RR and RL at the rear of the vehicle, and the running stability and the emergency avoidance performance in the medium / high speed range can be improved.

  By the way, the actuator 30 of the present embodiment is configured as shown in FIGS. 4 to 7, and is connected to the left and right lower arms 13 and 14 via the lever 41 and the like, so that the lever ratio is set appropriately. The thrust with respect to the lower arms 13 and 14 and the stroke speed can be adjusted. Further, when the vehicle moves forward (when traveling forward), a tensile force is applied to the lower arms 13 and 14, but a compression force is applied to the output shaft 32 of the actuator 30 via the lever 41. Will be. As described above, when the vehicle is traveling forward with absolutely high frequency, a compressive force is applied to the output shaft 32 of the actuator 30, so that a heavy burden can be reduced. Further, the swinging and torsional force of the rear axle (axle 10) transmitted through the lower arms 13 and 14 is absorbed by the lever 41 and is not directly transmitted to the actuator 30. Also in this respect, the strength against the actuator 30 is high. The burden can be reduced.

  In addition to the above-described aspects, various aspects can be configured as shown in FIGS. For example, as shown in FIG. 10, if the actuator 30 is configured to be supported inside the vehicle with respect to the side rails 21 and 22, the actuator 30 can be accommodated between the parallel side rails 21 and 22. become. Alternatively, when there is no margin on both sides of the side rails 21 and 22, the actuator 30 may be configured to be supported on the lower side of the vehicle with respect to the side rails 21 and 22, as shown in FIG. For example, as shown in FIG. 11, the actuator 30 provided for these may be directly connected to the front end portions of the lower arms 13 and 14 without using a lever 41 or the like.

It is a top view which shows the suspension system of the vehicle rear part provided with the rear-axle adjustment mechanism which concerns on one Embodiment of this invention. It is a side view which shows arrangement | positioning of each link of the suspension system of the vehicle rear part in one Embodiment of this invention. It is a rear view which shows arrangement | positioning of each link of the suspension system of the vehicle rear part in one Embodiment of this invention. It is a partial section top view of an actuator in one embodiment of the present invention. It is a side view of an actuator in one embodiment of the present invention. It is a side view which expands and shows the connection part of the output shaft and lower arm of an actuator in one Embodiment of this invention. It is a partial section rear view which expands and shows the connection part of the output shaft of an actuator in one Embodiment of this invention, and a lower arm. It is a top view showing the state where the rear axle adjustment mechanism was driven and the wheel behind the vehicle was steered in one embodiment of the present invention. It is a top view showing the state where the rear axle adjustment mechanism was driven in the embodiment of the present invention, and the wheel base behind the vehicle was extended. FIG. 10 is a plan view illustrating a configuration in which an actuator is supported on the inner side of a vehicle with respect to a side rail according to another embodiment of the present invention. FIG. 10 is a plan view showing a configuration in which an actuator is supported on the lower side of a vehicle with respect to a side rail according to still another embodiment of the present invention.

Explanation of symbols

RR, RL Wheel 10 Axle 11, 12 Upper arm 13, 14 Lower arm 15 Lateral rod 21, 22 Side rail 30 Actuator 31 Electric motor 32 Output shaft 36, 44 Bracket 41 Lever

Claims (7)

  The vehicle is mounted on a vehicle having a link type rigid axle suspension in which the left and right wheels on the rear side of the vehicle are connected by one axle and has at least four links, and the axle is displaced with respect to the vehicle body to displace the axle with respect to the vehicle body. A rear axle adjustment mechanism for adjusting a relative position, comprising: an actuator that is fixed to the vehicle body and connected to at least one of the four links, and that drives the link in the longitudinal direction of the vehicle. A rear axle adjustment mechanism for a vehicle, wherein the relative position of the axle with respect to the vehicle body is adjusted in accordance with the movement of the link in the front-rear direction.   The vehicle body includes a pair of side rails arranged in parallel to the left and right of the vehicle and extending in the front-rear direction of the vehicle, and the link-type rigid axle suspension is arranged on the left and right of the vehicle and connected to the axle. A pair of upper arms and a pair of lower arms are provided, and the actuator is supported by a side rail on one of the left and right sides of the vehicle and is connected to a front end portion of a lower arm on the left and right side of the vehicle. The rear axle adjustment mechanism of the vehicle according to 1.   The vehicle body includes a pair of side rails arranged in parallel to the left and right of the vehicle and extending in the front-rear direction of the vehicle, and the link-type rigid axle suspension is arranged on the left and right of the vehicle and connected to the axle. A pair of upper arms and a pair of lower arms are provided, and the actuators are supported by side rails on both the left and right sides of the vehicle, and are connected to front end portions of the left and right lower arms of the vehicle, respectively. The rear axle adjustment mechanism of the vehicle according to 1.   The lever is rotatably supported by the side rail and is orthogonal to the side rail. The actuator is rotatably supported at one end of the lever, and the front end of the lower arm is disposed at the other end of the lever. 4. The rear axle adjusting mechanism for a vehicle according to claim 2 or 3, wherein the rear axle is rotatably supported.   4. The rear axle adjustment mechanism for a vehicle according to claim 2, wherein the actuator is supported outside the vehicle with respect to the side rail.   The vehicle rear axle adjusting mechanism according to claim 2 or 3, wherein the actuator is supported on the inner side of the vehicle with respect to the side rail.   The rear axle adjustment mechanism of the vehicle according to claim 2 or 3, wherein the actuator is supported on the lower side of the vehicle with respect to the side rail.

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