JP5685207B2 - Engine support structure - Google Patents

Description

  The present invention relates to a support structure that supports an engine, and more particularly, to an engine support structure that absorbs energy with a vehicle body skeleton frame in the event of a collision from the vehicle longitudinal direction.

As a conventional engine support structure, there is one described in Patent Document 1, for example. In the structure described in Patent Document 1, as shown in FIG. 4A, a predetermined distance is provided below the vehicle body front skeleton frame 50 extending in the vehicle front-rear direction and above and below the vehicle body front skeleton frame 50. A sub frame 51 extending in the vehicle front-rear direction is disposed, and the front side of the vehicle body front skeleton frame 50 and the front side of the sub frame 51 are connected by a connecting member 52 extending vertically. An engine is mounted on the subframe 51.
Further, when a predetermined load or more is input from the front of the vehicle toward the rear due to a collision or the like, the vehicle body front skeleton member 50 is crushed and deformed to increase the efficiency of energy absorption with respect to the input load. .

JP 2002-160663 A

  Here, at the time of a collision, a collision input acts on the vehicle body skeleton frame 50 via the bumper 53. In order to reduce the deformation of the passenger compartment from the viewpoint of occupant protection, it is desirable to efficiently absorb the energy of the collision input by the deformation of the vehicle body skeleton frame 50 on the front side or the rear side in the vehicle longitudinal direction from the passenger compartment. The deformation mode in which the vehicle body frame 50 can absorb the collision input energy most efficiently is a mode in which the body frame 50 compresses and deforms in the axial direction.

However, in the prior art, as shown in the schematic diagram of FIG. 4, the connecting member 52 that connects the sub frame 51 and the vehicle body frame 50 is rigidly fixed to the vehicle frame 50 and extends in the vehicle vertical direction. It has a predetermined length. For this reason, when a vehicle front-rear direction force is input to the vehicle body frame 50 at the time of a collision, the center position of the rigidity of the integrated structure of the vehicle body frame 50 and the connection member 52 that receives the collision input in the AA cross section of FIG. Since G is at point G on the lower side of the vehicle in the vertical direction from the collision input point, moment A is applied centering on point G, and moment B is applied even in the middle in the longitudinal direction. As shown in the schematic diagram shown in b), the body frame 50 may be deformed in the out-of-plane direction. In the case of deformation in the out-of-plane direction, the amount of the body skeleton frame 50 that is crushed in the compression direction (vehicle front-rear direction) is reduced, and the energy absorption amount is reduced.
The present invention has been made paying attention to the above points, and it is an object of the present invention to improve the energy absorption efficiency in the vehicle body skeleton frame with respect to a collision input in the vehicle longitudinal direction.

In order to solve the above-described problems, the present invention provides a vehicle body skeleton frame having an extending portion extending in the vehicle front-rear direction, a subframe that is disposed below the vehicle body skeleton frame and supports an engine, and the extension An engine support structure comprising: a connecting member that connects the portion and the subframe;
The sub-frame has a frame main body portion that vertically faces the extension portion and extends in the vehicle front-rear direction in parallel with the extension portion,
The connecting member is orthogonal to both the extending part and the frame main body part,
The vehicle body skeleton frame has an inclined portion that is bent downward continuously from the rear end portion of the extending portion in the vehicle front-rear direction, and between the lower position of the inclined portion and the rear end portion of the subframe. Is elastically supported through an insulator,
By connecting the extending part and the upper part of the connecting member via an elastic body that is disposed closer to the extending part than the subframe and is elastically deformable in the vehicle longitudinal direction, the vehicle width direction is About the restraining force in the rotation direction as the shaft, the restraining force at the connecting portion between the extending portion and the connecting member is smaller than the restraining force at the connecting portion between the subframe and the connecting member. .

  According to the present invention, the deformation mode of the vehicle body skeleton frame at the time of a collision from the vehicle body longitudinal direction is predominantly the compression deformation in the vehicle longitudinal direction even when the vehicle frame and the sub frame are spaced apart from each other in the vertical direction. As a result, collision energy can be absorbed efficiently.

It is a typical side view which shows the engine support structure which concerns on embodiment based on this invention, Comprising: (a) shows the state before a deformation | transformation, (b) shows the state after a deformation | transformation, respectively. It is sectional drawing which shows the connection structure with the sub member of the front frame side member via the connection member which concerns on embodiment based on this invention. It is a figure which shows another engine support structure which concerns on embodiment based on this invention. It is a typical side view explaining the conventional engine support structure, Comprising: (a) shows the state before a deformation | transformation, (b) shows the state after a deformation | transformation, respectively.

Next, embodiments of the present invention will be described with reference to the drawings.
In the present embodiment, a vehicle configuration of a front engine in which an engine is mounted on the front side in the vehicle front-rear direction will be described as an example. FIG. 1 is a schematic side view showing an engine support structure of the present embodiment.
The body skeleton frame 1 includes a pair of left and right front skeleton side members 2 (extending portions) extending in the vehicle front-rear direction and a plurality of cross skeleton members extending in the vehicle width direction and connecting the left and right front skeleton side members 2. (Not shown). Each of the front skeleton side members 2 is bent downward at the portion reaching the dash panel to form an inclined portion 2a, and an extension in which the rear in the vehicle front-rear direction is disposed below and on both sides of the vehicle body floor relative to the inclined portion 2a. It is a side member 2b. Reference numeral 11 denotes a bumper.

Below the vehicle body skeleton frame 1, a sub-frame 3 is disposed to face each other with a predetermined distance in the vertical direction. The subframe 3 is composed of left and right frame main body portions 4 extending in the vehicle front-rear direction so as to face the front skeleton side member 2 and a cross submember (not shown) connecting the left and right frame main body portions 4. It is configured. The sub-frame 3 is elastically supported by the front skeleton side member 2 at the front end and the rear end of the frame body 4.

Next, the elastic support structure will be described.
The front end portion of the front skeleton side member 2 and the front end portion of the frame main body portion 4 are connected via a connecting member 5 extending vertically. The lower portion of the connecting member 5 is integrally coupled to the front end portion of the frame main body portion 4.
The upper part of the connecting member 5 is connected to the front end of the front skeleton side member 2 via an insulator 6. As shown in FIG. 2, the insulator 6 is configured by an elastic body 6c interposed between an inner cylinder 6a and an outer cylinder 6b that are arranged coaxially with their axes directed vertically. The outer cylinder 6b is fixed to the upper part of the connecting member 5 by press-fitting or the like, and the inner cylinder 6a is fixed to the front skeleton side member 2 via mounting bolts 12 penetrating the inner cylinder 6a. . Here, the length of the outer cylinder 6 b is shorter than the inner cylinder 6 a, and a predetermined gap is provided between the upper end surface of the outer cylinder 6 b and the lower surface of the front skeleton side member 2.
The end portion after the frame main body portion 4, through the similar insulator 8, is elastically supported at the bottom position of the inclined portion 2a of the front framework side members 2.
An engine 7 is mounted on the subframe 3 via a mount member 13.

Next, functions and effects of this embodiment will be described.
In the engine support structure described above, the connecting member 5 is integrally coupled to the subframe 3 so that both the members 5 and 3 have high rigidity, that is, a large restraining force in the rotational direction around at least the vehicle width direction. Linked in state. On the other hand, the connecting member 5 is connected to the front skeleton side member 2 via the elastic body 6c so that the connecting member 5 can be swung with each other, that is, connected in a state where the rigidity of the connecting portion is low. It is connected in a state where the restraining force in the rotational direction is small and close to zero. For this reason, when an input in the vehicle longitudinal direction is applied to the front skeleton side member 2, the rigidity in the vehicle vertical direction at the connection position (AA position in FIG. 1 ) between the front skeleton side member 2 and the connection member 5 is obtained. The center position G substantially coincides with the cross-sectional center of the front skeleton side member 2, and the front skeleton side member 2 of the front skeleton side member 2 is also located in the longitudinal direction of the front skeleton side member 2 (BB position in FIG. 1 ). The center position G ′ of rigidity in the direction substantially coincides with the cross-sectional center of the front skeleton side member 2.

  Accordingly, when a force in the vehicle longitudinal direction is input to the front skeleton side member 2 due to a collision, the moments around the rigid center positions G and G ′ due to the collision input are not generated or are small. Even if there is a distance between the frame and the sub-frame 3 and the sub-frame 3 is connected by the connecting member 5, the bending moment input to the front skeleton side member 2 by the reaction force of the sub-frame 3 at the time of collision can be reduced. As a result, the deformation in the compression direction becomes dominant with respect to the vehicle front-rear direction input at the time of the collision, and the front skeleton side member 2 does not deform in the out-of-plane direction, as shown in FIG. The energy absorption amount increases.

  Further, as described above, as the front skeleton side member 2 is compressed in the vehicle front-rear direction, the upper portion of the outer cylinder 6 b fixed to the connection member 5 is connected to the connection member 5, although the upper portion thereof is inclined in the vehicle front-rear direction. Since a predetermined gap is provided between the front skeleton side member 2 and the lower surface of the front skeleton side member 2, the connection between the front skeleton side member 2 and the connecting member 5 is continued until the upper end of the outer cylinder 6 b comes into contact with the front skeleton side member 2. It is possible to prevent the restraining force at the portion from increasing. Even if the upper end of the outer cylinder 6b abuts against the front skeleton side member 2 and the restraining force in the rotational direction is increased, it is much smaller than the restraining force at the connecting portion between the connecting member 5 and the subframe 3. The vertical bending moment input to the front skeleton side member 2 is small, so that the deformation in the compression direction tends to remain dominant.

  Further, since the front end portion and the rear end portion of the subframe 3 on which the engine 7 is mounted are elastically supported by the front skeleton side member 2 via the insulators 6 and 8, the subframe 3 mounted by the vibration of the engine 7 is used. It is difficult to transmit the vibration of the frame 3 to the front skeleton side member 2. That is, noise and vibration performance can be improved by preventing the vibration of the sub-frame 3 that is vibrated by the vibration of the engine 7 from being transmitted to the front skeleton side member 2.

  Here, in the above-described embodiment, the elastic members 6c are interposed so that both the members 2 and 5 are swingably connected, and the vehicle width direction of the connecting portion between the connecting member 5 and the front skeleton side member 2 is used as an axis. Although the restraining force in the rotational direction is reduced, the present invention is not limited to this. For example, the binding force in at least the rotational direction about the width direction may be set to zero or low by connecting the shaft with a pin joint or a universal joint whose direction is the vehicle width direction.

Moreover, in the said embodiment, although the connection member 5 and the sub-frame 3 are integrally connected, even if it connects the connection member 5 and the sub-frame 3 via the elastic body 10 like FIG. good. In this case, the rigidity of the elastic body 10 that connects the connecting member 5 and the subframe 3 is set to be larger than the rigidity of the elastic body 6 c that is interposed between the front skeleton side member 2 and the connecting member 5. If it does in this way, it can make it difficult to transmit the vibration of subframe 3 to front frame side member 2 further, maintaining the above-mentioned effect.
Further, in the above embodiment, the case where the present invention is applied to the vehicle configuration of the front engine is illustrated, but the present invention can be applied even to the vehicle configuration of the rear engine. Can be obtained.

1 Body frame 2 Front frame side member (extension)
Reference Signs List 3 Subframe 4 Frame body 5 Connection 6 Insulator 6a Inner cylinder 6b Outer cylinder 6c Elastic body 7 Engine 10 Elastic body 12 Mounting bolt

Claims (6)

A vehicle body skeleton frame having an extending portion extending in the longitudinal direction of the vehicle, a subframe disposed below the vehicle body skeleton frame to support the engine, and a connecting member connecting the extension portion and the subframe; An engine support structure comprising:
The sub-frame has a frame main body portion that vertically faces the extension portion and extends in the vehicle front-rear direction in parallel with the extension portion,
The connecting member is orthogonal to both the extending part and the frame main body part,
The vehicle body skeleton frame has an inclined portion that is bent downward continuously from the rear end portion of the extending portion in the vehicle front-rear direction, and between the lower position of the inclined portion and the rear end portion of the subframe. Is elastically supported through an insulator,
By connecting the extending part and the upper part of the connecting member via an elastic body that is disposed closer to the extending part than the subframe and is elastically deformable in the vehicle longitudinal direction, the vehicle width direction is An engine support structure characterized in that the restraining force at the connecting portion between the extending portion and the connecting member is smaller than the restraining force at the connecting portion between the subframe and the connecting member with respect to the restraining force in the rotational direction as the shaft. . The connecting member is composed of a member extending in the vertical direction,
The extending portion and the connecting member are connected via an insulator in which an elastic body is interposed between an outer cylinder and an inner cylinder whose shafts are directed upward and downward, and extend one of the inner cylinder and the outer cylinder. 2. The engine support structure according to claim 1, wherein the engine support structure is fixed to an existing portion, and the other of the inner cylinder and the outer cylinder is fixed to an upper portion of the connecting member.   The engine support structure according to claim 2, wherein the inner cylinder is fixed to the extending portion by a bolt penetrating the inner cylinder, and the outer cylinder is fixed to an upper portion of the connecting member.   The engine support structure according to claim 3, wherein a vertical gap is provided between the upper end of the connecting member and the upper end of the outer cylinder, and the extending portion.   The said sub-frame and the connection member are connected via the elastic body whose rigidity is larger than the connection part of the said extension part and a connection member, The any one of Claims 1-4 characterized by the above-mentioned. The engine support structure described in the item.   The engine support structure according to any one of claims 1 to 4, wherein the subframe and the connecting member are fixed integrally.

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