JP2006051866A - Car body structure of vehicle equipped with chassis frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a car body structure of a vehicle equipped with a chassis frame which can reduce a roll directional vibration of a cab occurring when a torsional vibration in the vertical opposite phase is input to the chassis frame. <P>SOLUTION: The vehicle 1 is equipped with the chassis frame 10 with which the cab 20 is combined through cab mounts 13, 14 and 15. In the vehicle 1, the attaching positions of the cab mounts 13, 14 and 15, a spring rate of the cab mounts 13, 14 and 15, and the rigidity distribution of the chassis frame 10 are set in such a manner that moments Ma1 and Ma2 in the rolling direction being applied to the cab 20 and a moment Mb1 in the rolling direction being applied to the cab 20 may be canceled each other. In this case, the moments Ma1 and Ma2 in the rolling direction are applied to the cab 20 by the cab mounts 13 and 14 which are arranged in the vehicle front side of the nodal position S1 of a torsional vibration mode of the chassis frame 10. The moment Mb1 in the rolling direction is applied to the cab 20 by the cab mount 15 which is arranged in the vehicle rear side of the nodal position S1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle body structure including a chassis frame.

  In the cab mount structure that elastically supports the cab on the chassis frame of the vehicle, the axis of the compression direction of each of the left and right cab mounts is inclined, and the elastic main shaft by both cab mounts is aligned with or close to the inertia main shaft of the cab The cab mount structure set to 1 is described in Patent Document 1 below.

  When a torsional vibration in the opposite phase is input to the chassis frame via a spring when traveling on rough roads, the cab is parallel to the rotational direction (roll direction) vibration around the inertial spindle and the lateral direction of the inertial spindle. This produces a translational vibration that displaces the

According to this cab mount structure, since the distance between the elastic main shaft of both cab mounts and the inertia main shaft of the cab is shortened, it is possible to reduce translational vibration in the horizontal direction applied to the cab via the left and right cab mounts. .
JP 2003-220968 A

  However, in the cab mount structure, it is not possible to reduce the vibration in the roll direction of the cab that occurs when torsional vibration in the opposite phase is input to the chassis frame.

  The present invention has been made to solve the above-described problems, and includes a chassis frame that can reduce vibration in the roll direction of the cab that occurs when torsional vibration in the opposite phase is input to the chassis frame. An object of the present invention is to provide a vehicle body structure.

  A vehicle body structure including a chassis frame according to the present invention is a vehicle body structure including a chassis frame to which a cab is coupled via a plurality of cab mounts. The moment in the roll direction applied to the cab by the cab mount arranged in the front and the moment in the roll direction added to the cab by the cab mount arranged at the rear of the vehicle with respect to the node position cancel each other. At least one of a cab mount mounting position, a cab mount characteristic and a node position is set.

  According to the vehicle body structure including the chassis frame according to the present invention, at least one of the mounting position of the cab mount, the characteristics of the cab mount, and the node position is set as described above. The moment in the roll direction applied to the cab from the cab mount disposed in front and the moment in the roll direction applied to the cab from the cab mount disposed behind the vehicle rather than the node position act to cancel each other. Therefore, it becomes possible to reduce the vibration of the cab in the roll direction.

  The characteristic of the cab mount is preferably the spring constant of the cab mount. Since the spring constant of the cab mount can be changed relatively easily, the degree of freedom of setting can be increased.

  The node position is preferably set by changing the rigidity distribution of the chassis frame. By changing the rigidity distribution of the chassis frame, the torsion amount of each part of the chassis frame when the torsional vibrations in the opposite phase are input is changed. Therefore, by appropriately setting the rigidity distribution of the chassis frame, the node position in the torsional vibration mode can be moved to an appropriate position.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the roll direction vibration of the cab which arises when the torsional vibration of an up-down phase is input into the chassis frame.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts.

  First, the vehicle body structure of the vehicle provided with the chassis frame according to the embodiment will be described with reference to FIGS. FIG. 1 is a side view schematically showing a vehicle body structure of a vehicle 1 according to the embodiment. 2 is a cross-sectional view in the II-II direction in FIG. FIG. 3 is a cross-sectional view in the III-III direction in FIG. 4 is a cross-sectional view in the IV-IV direction in FIG. In the present specification, the forward direction when the vehicle is moving forward is defined as “front”, and terms such as front and rear, left and right, and up and down are used.

  In addition, the inertial main axis referred to in this specification is a couple of forces that attempt to change the direction of the rotation axis as seen from the coordinate system that rotates together with the cab when the cab that is a rigid body is rotated around a certain axis. An axis that does not occur. Furthermore, the elastic main axis as used in this specification means that when a force is applied along a certain axis, the direction of the force coincides with the direction of displacement of the applied point, and the plane including the applied point is linearly displaced. An axis that does not cause displacement, which is the center of elastic recovery.

  The vehicle 1 includes a chassis frame 10 having a pair of left and right side members 11 and a plurality of cross members 12 disposed between the pair of side members 11 along the vehicle width direction. In FIG. 1, S <b> 1 indicates a node position of the torsional vibration mode of the chassis frame 10 when torsional vibrations (see the broken line R <b> 1 and the alternate long and short dash line R <b> 2) are input to the chassis frame 10.

  Six cab mounts 13, 13, 14, 14, 15, 15 are attached to the side member 11 and the cross member 12 constituting the chassis frame 10 symmetrically. The cab mounts 13, 14, and 15 are members having a support function and an anti-vibration function, each having a rubber insulator.

  The cab 20 is elastically coupled to the chassis frame 10 through the six cab mounts 13, 13, 14, 14, 15, 15. A seat 21 or the like is attached to the cab 20. A deck 22 is attached to the chassis frame 10.

  The chassis frame 10 is supported by a suspension device 34 that includes springs 30 and 31 that alleviate the impact received from the road surface. Wheels 32 and 33 are rotatably attached to the front and rear suspension devices 34.

  Here, the mounting positions of the cab mounts 13, 14, and 15, the spring constants of the cab mounts 13, 14, and 15 and the node position S1 of the torsional vibration mode of the chassis frame 10 are set as follows. That is, the moment Ma in the roll direction applied to the cab 20 by the cab mounts 13 and 14 disposed in front of the vehicle relative to the node position S1 of the chassis frame 10 in the torsional vibration mode, and the node position of the chassis frame 10 in the torsional vibration mode. It is set so that the magnitude of the moment Mb in the roll direction applied to the cab 20 by the cab mount 15 disposed at the rear of the vehicle with respect to S1 coincides or substantially coincides, and the respective directions are reversed.

ただし、Ｆａｉは節位置よりも車両前方に配置されたキャブマウントを介してキャブに入力される力、Ｌａｉは左右のキャブマウント間の距離である。ここで、Ｆａｉ＝ｋａｉ×Ｄａｉである。なお、ｋａｉはキャブマウントのばね定数、Ｄａｉはキャブマウントの変位量である。 However, the moment Ma includes a roll-direction moment Ma1 applied to the cab 20 by the cab mount 13 (see FIG. 2) and a roll-direction moment Ma2 applied to the cab 20 by the cab mount 14 (see FIG. 3). It is an added value and is obtained by the following equation. In the present embodiment, n = 2.

Here, Fai is a force input to the cab via the cab mount disposed in front of the vehicle relative to the node position, and Lai is a distance between the left and right cab mounts. Here, Fai = kai × Dai. Here, kai is the spring constant of the cab mount, and Dai is the displacement amount of the cab mount.

ただし、Ｆｂｉは節位置よりも車両後方に配置されたキャブマウントを介してキャブに入力される力、Ｌｂｉは左右のキャブマウント間の距離である。ここで、Ｆｂｉ＝ｋｂｉ×Ｄｂｉである。なお、ｋｂｉはキャブマウントのばね定数、Ｄｂｉはキャブマウントの変位量である。 On the other hand, the moment Mb, that is, the moment Mb1 (see FIG. 4) in the roll direction applied to the cab 20 by the cab mount 15 is obtained by the following equation. In the present embodiment, n = 1.

Here, Fbi is a force input to the cab via a cab mount disposed behind the vehicle from the node position, and Lbi is a distance between the left and right cab mounts. Here, Fbi = kbi × Dbi. Here, kbi is the spring constant of the cab mount, and Dbi is the displacement amount of the cab mount.

  Thus, the moment Ma and the moment Mb are respectively the distances Lai and Lbi between the left and right cab mounts, the spring constants kai and kbi of the cab mounts 13, 14, and 15 and the displacement amounts Dai and Dbi of the cab mounts 13, 14, and 15. Determined by. Accordingly, by appropriately adjusting the distances Lai, Lbi between the left and right cab mounts, the spring constants kai, kbi of the cab mounts 13, 14, 15 and the mounting positions of the cab mounts 13, 14, 15 and the node positions S1, It is possible to set so that the magnitudes of Ma and moment Mb coincide or substantially coincide with each other and their directions are reversed.

  The distances Lai, Lbi between the left and right cab mounts are adjusted by moving the mounting positions of the cab mounts 13, 14, 15 in the vehicle width direction. For example, the distances Lai and Lbi between the left and right cab mounts can be adjusted by moving the mounting positions of the cab mounts 13, 14 and 15 from the vehicle outer wall surface of the side member 11 to the vehicle inner wall surface. Further, by moving the mounting positions of the cab mounts 13, 14, and 15 on the cross member 12 in the vehicle width direction, the distances Lai and Lbi between the left and right cab mounts can be adjusted.

  The spring constants of the cab mounts 13, 14 and 15 are adjusted by changing the load receiving method (for example, compression type or shear type), the material of rubber (for example, natural rubber or butyl rubber), the shape, and the like.

  Since the displacement amounts Dai and Dbi of the cab mounts 13, 14, and 15 change according to the amount of twist of the chassis frame 10, by changing the mounting position of the cab mounts 13, 14, and 15, It is adjusted by moving the node position S1 in the torsional vibration mode. For example, by moving the mounting positions of the cab mounts 13, 14, 15 on the side member 11, the mounting positions can be adjusted in the vehicle longitudinal direction. Further, by moving the mounting positions of the cab mounts 13, 14, 15 on the cross member 12, the mounting positions can be adjusted in the vehicle width direction.

  The node position S1 of the torsional vibration mode of the chassis frame 10 is adjusted by changing the rigidity distribution of the chassis frame 10. The rigidity distribution of the chassis frame 10 can be adjusted, for example, by changing the cross-sectional shape, thickness, material, and the like of the side member 11 and the cross member 12 constituting the chassis frame 10. Here, a case where the node position of the chassis frame is adjusted by changing the cross-sectional shape of the side member will be described as an example.

  FIG. 5 shows a node position S2 in the case where the chassis frame 10A is constituted by the side member 11A having a closed cross-sectional structure in the shape of a character. On the other hand, a side member in which the front portion of the vehicle (see the hatched portion in FIG. 6) has a closed cross-sectional structure in the shape of a mouth and the rear portion of the vehicle has an open cross-sectional structure in which a part of the vertical wall portion is cut off in the vehicle width direction. FIG. 6 shows a node position S3 when the chassis frame 10B is configured using 11B.

  Since the open cross-sectional structure is less rigid than the closed cross-sectional structure, the torsion amount increases when torsional vibrations in the opposite phase are input to the chassis frame. Therefore, the node position S3 of the chassis frame 10B moves to the rear of the vehicle compared to the node position S2 of the chassis frame 10A. Therefore, the node position of the torsional vibration mode of the chassis frame can be adjusted by appropriately arranging the closed cross-section structure portion and the open cross-section structure portion.

  Next, the operation of this embodiment will be described. When torsional vibrations in reverse phase (see broken line R1 and alternate long and short dash line R2 in FIG. 1) are input to chassis frame 10, counterclockwise moments Ma1 and Ma2 are added to cab 20 by inputs from cab mounts 13 and 14, respectively. Is done. On the other hand, a clockwise moment Mb <b> 1 is added to the cab 20 by the input from the cab mount 15.

  As described above, in the present embodiment, the cab mounts 13, 14, 15 of the cab mounts 13, 14, 15 are arranged such that the sum of the moments Ma 1 and Ma 2 and the magnitude of the moment Mb 1 are the same or substantially the same and the directions are reversed. The mounting position, the spring constant of the cab mounts 13, 14, 15 and the node position S1 of the torsional vibration mode of the chassis frame 10 are set. Therefore, the added value of moments Ma1 and Ma2 and moment Mb1 cancel each other, so that vibration of cab 20 in the roll direction is reduced.

  As described above, according to the present embodiment, when the torsional vibration in the up-down phase is input to the chassis frame 10, the vibration in the roll direction of the cab 20 can be reduced, so that the vibration characteristics of the vehicle 1 are improved. It becomes possible.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, the number of cab mounts is not limited to six. The applied vehicle is not limited to a truck having a deck, and can be applied to any vehicle provided with a chassis frame.

It is the side view which showed typically the vehicle body structure of the vehicle which concerns on embodiment. It is sectional drawing of the II-II direction in FIG. It is sectional drawing of the III-III direction in FIG. It is sectional drawing of the IV-IV direction in FIG. It is a figure which shows the node position of the torsional vibration mode of a vehicle. It is a figure which shows the node position of the torsional vibration mode of the vehicle which changed the rigidity distribution of the chassis frame.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 10 ... Chassis frame, 11, 12, 13 ... Cab mount, 20 ... Cab, 21 ... Seat, 22 ... Deck, 30, 31 ... Spring, 32, 33 ... Tire, 34 ... Suspension, S1, S2, S3: Node position in torsional vibration mode.

Claims (3)

In a vehicle body structure of a vehicle including a chassis frame to which a cab is coupled through a plurality of cab mounts,
A moment in a roll direction applied to the cab by a cab mount disposed in front of the vehicle with respect to a node position in the torsional vibration mode of the chassis frame, and a cab mount disposed in the rear of the vehicle from the node position in the cab. A chassis frame, wherein at least one of the mounting position of the cab mount, the characteristics of the cab mount, and the node position is set so that the moment in the roll direction to be added cancels each other. Vehicle body structure equipped.   The vehicle body structure having a chassis frame according to claim 1, wherein the characteristic of the cab mount is a spring constant of the cab mount.   The vehicle body structure having a chassis frame according to claim 1, wherein the node position is set by changing a rigidity distribution of the chassis frame.

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