JP5469898B2 - Body structure - Google Patents

Description

  The present invention relates to a vehicle body structure in which a subframe is attached to a front portion of a vehicle body frame.

  Some vehicles, such as automobiles, employ a vehicle body structure in which a subframe that supports a suspension and an engine is attached to the front portion of the vehicle body frame. The structure for attaching the subframe includes a fixed attachment structure and a floating attachment structure (floating support structure).

  The fixed attachment structure is a structure in which the subframe is directly attached to the vehicle body frame. When this fixed mounting structure is adopted, when the collision energy acts on the vehicle body from the front, the sub frame can absorb the collision energy integrally with the vehicle body frame.

  By the way, while the vehicle is traveling, vibration is transmitted from the wheel to the subframe via the suspension, and vibration is transmitted from the engine to the subframe via the mount. In the fixed mounting structure, these vibrations are transmitted from the sub frame to the vehicle body frame. For this reason, it is disadvantageous for suppressing vibration and noise transmitted to the passenger compartment and improving ride comfort and comfort of the passenger.

  On the other hand, the floating attachment structure is a structure in which the subframe is attached to the vehicle body frame via an elastic body (anti-vibration rubber). When this floating mounting structure is adopted, vibrations transmitted from the wheels to the subframe via the suspension and vibrations transmitted from the engine to the subframe via the mount are reduced by the elastic body while the vehicle is running. So it is difficult to get to the passenger compartment. For this reason, it is advantageous in suppressing the vibration and noise transmitted to the passenger compartment and improving the ride comfort and comfort of the occupant.

  However, as described above, an elastic body is interposed between the vehicle body frame and the subframe. The elastic body is deformed when collision energy acts on the vehicle body from the front. For this reason, some measures are required to efficiently absorb the collision energy by the subframe. In that case, it is necessary to prevent the structure from becoming complicated and to suppress an increase in the weight of the vehicle body as much as possible. If the vehicle body weight increases, the fuel consumption of the vehicle (the distance that can be traveled per unit capacity of fuel) decreases.

  In recent years, the development of a floating mounting structure that takes into account collision energy has been promoted. This improved floating mounting structure is designed to drop off some of the bolts that connect the rear end of the subframe to the body frame when a certain amount of collision energy acts on the body frame. The rear end of the subframe is dropped (for example, see Patent Document 1). Also in this technique, it is more preferable that the collision energy can be efficiently absorbed by the subframe.

  As is clear from the above description, the vehicle body structure suppresses vibrations and noise transmitted to the passenger compartment to increase the ride comfort and comfort of the occupant, and the occupant when collision energy acts on the vehicle body. It is demanded to improve the protection performance of the.

Japanese Patent Application Laid-Open No. 11-171046

  The present invention provides a vehicle body structure technology that can improve the passenger's protection performance when collision energy acts on the vehicle body while maintaining the ride comfort and comfort of the passenger during normal driving. The issue is to provide.

According to the first aspect of the present invention, the front and rear end portions of the sub-frames disposed below the front side frames are provided on the left and right front side frames extending front and rear in the front portion of the vehicle body. In the vehicle body structure that is attached via the rear elastic bodies, the rear ends of the left and right front side frames are joined to the floor frame via front side extensions that extend rearward and downward. Is a structure in which the rear end portion and the rear elastic body of the subframe are attached by a connecting mechanism, and the connecting mechanism is configured to drop the rear end portion and the rear elastic body of the subframe downward from the front side extension portion. while the enclosure so as to regulate a structure attached to the front side extension portion, the connecting mechanism comprises a bracket provided on the front side extension A support member having a substantially U-shaped cross section when viewed from the front of the vehicle body, the upper open end of which is coupled to the bracket, and the bracket and the support member are provided so as to penetrate vertically and tighten the bracket and the support member vertically. It consists of bolts and nuts, and surrounds the rear end portion of the subframe and the rear elastic body with the bottom surface of the bracket and the support member and sandwiches it vertically, and allows the bolt to vertically penetrate the rear elastic body, The rear end portion of the subframe and the rear elastic body are attached to the bracket and the support member.

According to a second aspect of the present invention, the front and rear end portions of the sub-frames disposed below the front side frames are provided on the left and right front side frames extending front and rear at the front portion of the vehicle body. In the vehicle body structure that is attached via the rear elastic bodies, the rear ends of the left and right front side frames are joined to the floor frame via front side extensions that extend rearward and downward. Is a configuration in which the rear end portion of the subframe and the rear elastic body are attached by a connecting mechanism, and the connecting mechanism is configured to attach the rear end portion of the subframe and the rear elastic body downward from the front side extension portion. It is configured to be attached to the front side extension while enclosing it so as to prevent it from falling off, and the connecting mechanism is a bracket provided on the front side extension. A support member having a substantially U-shaped cross section when viewed from the front of the vehicle body, the open end of which is connected to the bracket, and a bracket and a support member that pass through the bracket and the support member. The rear end of the subframe and the rear elastic body are surrounded by the bottom surface of the bracket and the support member, and are sandwiched up and down by passing the bolt up and down through the rear elastic body. The rear end portion and the rear elastic body of the subframe are attached to the bracket and the support member.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the bolt is provided with a washer having a large outer diameter integrally or separately, and the nut fastened to the bolt also has a large outer diameter. The washer is provided integrally or separately.

  The invention according to claim 1 employs a so-called floating attachment structure in which the subframe is attached to the front side frame via an elastic body. Therefore, vibrations transmitted from the wheels to the subframe through the suspension and vibrations transmitted from the engine to the subframe through the elastic body while the vehicle is traveling are alleviated by the elastic body, and are therefore not easily transmitted to the passenger compartment. . For this reason, vibration and noise transmitted to the passenger compartment can be suppressed, and the ride comfort and comfort of the occupant can be enhanced.

  Furthermore, the invention according to claim 1 is configured such that the rear end portion of the subframe and the rear elastic body are attached to the front side extension provided at the rear end of the front side frame by the connecting mechanism. The coupling mechanism surrounds the rear end portion and the rear elastic body of the subframe so as to restrict the downward drop from the front side extension portion.

  For this reason, when the collision energy acts on the front surface of the vehicle body, the rear end portion of the subframe is restricted from dropping downward from the front side extension portion. Accordingly, since the subframe can be firmly connected to the front side frame and the front side extension, the collision energy can be efficiently absorbed by the subframe. That is, when the vehicle body receives collision energy, the subframe can be used as a collision energy absorbing member. Furthermore, collision energy can be reliably and efficiently transmitted from the rear end of the subframe to the floor frame via the front side extension. As a result, the occupant protection performance when collision energy acts on the vehicle body can be further enhanced.

  In addition, it is a simple configuration only having a coupling mechanism, and the subframe is utilized as a collision energy absorbing member, so that it is not necessary to provide another member for absorbing the collision energy. For this reason, an increase in vehicle body weight can be suppressed as much as possible. Therefore, it is extremely advantageous in increasing the fuel consumption of the vehicle.

  As described above, in the invention according to claim 1, (1) the vibration and noise transmitted to the passenger compartment are suppressed, and the ride comfort and comfort of the occupant are enhanced, and (2) the collision energy acts on the vehicle body. It is possible to simultaneously improve the performance of protecting the occupant.

In the present invention, the rear end portion and the rear elastic body of the subframe are surrounded by the bottom surface of the bracket and the support member and sandwiched vertically, and the bolt is vertically passed through the bracket, the support member, and the rear elastic body. Thus, the rear end portion of the sub-frame and the rear elastic body are attached to the front side extension portion. Regardless of such a simple configuration, when the collision energy acts on the front of the vehicle body, the rear end of the subframe is surely restricted from dropping downward from the front side extension. Can do. Therefore, collision energy can be efficiently transmitted from the rear end portion of the subframe to the floor frame via the front side extension.
In addition, a so-called floating mounting structure is configured by surrounding the subsequent elastic body with the bottom surface of the bracket and the support member and sandwiching the elastic body vertically. Therefore, during the traveling of the vehicle, vibration transmitted from the wheel to the subframe via the suspension and vibration transmitted from the engine to the subframe via the elastic body can be sufficiently mitigated by the elastic body.

In the invention according to claim 2, the left and right front side frames extending in the front-rear direction at the front portion of the vehicle body have the front end portion and the rear end portion of the sub-frames arranged below these front side frames, and the front elastic body. In the vehicle body structure that is attached via the rear elastic bodies, the rear ends of the left and right front side frames are joined to the floor frame via front side extensions that extend rearward and downward. Is a configuration in which the rear end portion of the subframe and the rear elastic body are attached by a connecting mechanism, and the connecting mechanism is configured to attach the rear end portion of the subframe and the rear elastic body downward from the front side extension portion. It is configured to be attached to the front side extension while enclosing so as to restrict the drop-off, and the connecting mechanism is a bracket provided on the front side extension. And a support member having a substantially U-shaped cross section when viewed from the front of the vehicle body, the open end of which is connected to the bracket, and the bracket and the support member are vertically penetrated and the bracket and the support member are tightened up and down. It consists of bolts and nuts provided, and the rear end of the sub-frame and the rear elastic body are surrounded by the bottom surface of the bracket and the support member and sandwiched up and down, and the bolt penetrates the rear elastic body up and down. Thus, the rear end portion and the rear elastic body of the subframe were attached to the bracket and the support member.
First, the invention according to claim 2 employs a so-called floating attachment structure in which the subframe is attached to the front side frame via an elastic body. Therefore, vibrations transmitted from the wheels to the subframe through the suspension and vibrations transmitted from the engine to the subframe through the elastic body while the vehicle is traveling are alleviated by the elastic body, and are therefore not easily transmitted to the passenger compartment. . For this reason, vibration and noise transmitted to the passenger compartment can be suppressed, and the ride comfort and comfort of the occupant can be enhanced.
Further, the invention according to claim 2 is configured such that the rear end portion of the subframe and the rear elastic body are attached to the front side extension provided at the rear end of the front side frame by the connecting mechanism. The coupling mechanism surrounds the rear end portion and the rear elastic body of the subframe so as to restrict the downward drop from the front side extension portion.
For this reason, when the collision energy acts on the front surface of the vehicle body, the rear end portion of the subframe is restricted from dropping downward from the front side extension portion. Accordingly, since the subframe can be firmly connected to the front side frame and the front side extension, the collision energy can be efficiently absorbed by the subframe. That is, when the vehicle body receives collision energy, the subframe can be used as a collision energy absorbing member. Furthermore, collision energy can be reliably and efficiently transmitted from the rear end of the subframe to the floor frame via the front side extension. As a result, the occupant protection performance when collision energy acts on the vehicle body can be further enhanced.
In addition, it is a simple configuration only having a coupling mechanism, and the subframe is utilized as a collision energy absorbing member, so that it is not necessary to provide another member for absorbing the collision energy. For this reason, an increase in vehicle body weight can be suppressed as much as possible. Therefore, it is extremely advantageous in increasing the fuel consumption of the vehicle.
As described above, in the invention according to claim 2, (1) the vibration and noise transmitted to the passenger compartment are suppressed, and the ride comfort and comfort of the occupant are improved, and (2) the collision energy acts on the vehicle body. It is possible to simultaneously improve the performance of protecting the occupant .

In the invention according to claim 3, since the washer having a large outer diameter is provided integrally or separately on the bolt and the nut, the load on the portion where the bracket, the support member and the bolt and nut are in contact with each other is increased. Can be dispersed efficiently. For this reason, it can restrict | limit more reliably that the rear-end part of a sub-frame falls below from a front side extension part.

1 is a perspective view of a front portion of a vehicle (Example 1) according to the present invention. It is a left view of the principal part in the front part of the vehicle shown by FIG. FIG. 3 is a cross-sectional view around the coupling mechanism (Example 1) shown in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. FIG. 4 is an exploded view of the coupling mechanism shown in FIG. 3. It is explanatory drawing explaining transmission of the collision energy which acted on the front of the vehicle shown by FIG. FIG. 3 is an action diagram of the vehicle body by collision energy acting on the front of the vehicle shown in FIG. 2. It is sectional drawing around the connection mechanism of Example 2 which concerns on this invention. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8. FIG. 9 is an exploded view of the coupling mechanism shown in FIG. 8.

  Hereinafter, embodiments of the present invention will be described in detail. "Front", "Rear", "Left", "Right", "Up", "Down" follow the direction seen from the driver, Fr is front, Rr is rear, Le is left, Ri is right , Up indicates the upper side, and Dw indicates the lower side.

First, Example 1 is demonstrated based on FIGS.
As shown in FIG. 1, the front portion of the vehicle body 11 in the vehicle 10 includes a vehicle body frame 20 and a subframe 30 attached to the front portion of the vehicle body frame 20.
The front part of the vehicle body frame 20 extends from the left and right front side frames 21, 21 extending in the front-rear direction of the vehicle body on both sides of the front part of the vehicle body, and in the vehicle width direction outside of the front side frames 21, 21 and upwards in the front-rear direction Left and right upper frames 22, 22; left and right damper housings 23, 23 spanned between the front side frames 21, 21 and the upper frames 22, 22; and front portions of the left and right front side frames 21, 21; A monocoque body mainly composed of a front bulkhead 24 coupled to the front portions of the left and right upper frames 22, 22 and a bumper 25 (see FIG. 2) spanned between the front ends of the left and right front side frames 21, 21 It is.

  As shown in FIG. 2, the rear ends 21a and 21a of the left and right front side frames 21 and 21 are joined to the front ends of the left and right floor frames 27 and 27 via front side extensions 26 and 26 that extend rearward and downward, respectively. Has been. Dashboards 28 for partitioning the engine room 12 and the vehicle compartment 13 are provided at the rear ends 21 a and 21 a of the left and right front side frames 21 and 21 and the rear ends of the left and right front side extensions 26 and 26. ing.

  As shown in FIGS. 1 and 2, the vehicle body frame 20 includes four front and rear left and right four parts (three in FIG. 1) in front parts of the left and right front side frames 21 and 21 and left and right front side extension parts 26 and 26. The sub-frame 30 is suspended through the anti-vibration elastic bush 50. That is, the left and right front end portions 31 of the subframe 30 are attached to the front portions of the left and right front side frames 21 and 21 via the front anti-vibration elastic bushings 50 and 50, respectively. The left and right rear end portions 32, 32 of the subframe 30 are attached to the left and right front side extensions 26, 26 via the rear vibration-proof elastic bushings 50, 50, respectively.

  As described above, the mounting structure of the present invention employs a so-called floating mounting structure in which the subframe 30 is attached to the vehicle body frame 20 via the four vibration-proof elastic bushes 50.

  The subframe 30 is formed of a substantially rectangular frame in plan view. The horizontal engine 41 (power source 41) is mounted on the right half, the transmission 42 is mounted on the left half, and the left and right suspensions 43 are mounted on the left and right sides. (The right side is omitted).

  The left suspension 43 includes an upper arm 44 attached to the front side frame 21 so as to be swingable up and down, a lower arm 45 attached to the left side of the subframe 30 so as to be swingable, and a cushion attached between the lower arm 45 and the damper housing 23. 46 is a front wheel suspension device for mainly suspending a front wheel (wheel) (not shown) on the vehicle body frame 20 with a main component of a knuckle 47 connected to the upper arm 44 and the lower arm 45. Since the left and right suspensions 43 have the same configuration, the description on the right side is omitted.

Next, the mounting structure of the rear end portion 32 of the subframe 30 and the rear vibration-proof elastic bush 50 (hereinafter simply referred to as “elastic bush 50”) will be described.
As shown in FIGS. 3 to 5, the rear end portion 32 and the elastic bushing 50 of the subframe 30 are attached to the front side extension 26 by a connecting mechanism 60. The coupling mechanism 60 is configured to be attached to the front side extension 26 while enclosing the rear end portion 32 of the subframe 30 and the rear elastic bushing 50 so as to restrict downward drop from the front side extension 26. The connection mechanism 60 includes a bracket 61, a support member 71, bolts 81, and nuts 82.

  The bracket 61 is a member provided on an inclined bottom surface 26a (an inclined surface 26a inclined downward from the front to the rear) in the front side extension 26, and is formed in a substantially right-angled triangle in side view where the hypotenuse contacts the bottom surface 26a. . The bracket 61 is, for example, a bent product of a steel plate, and includes a substantially horizontal bottom plate 62, a front plate 63 standing upright from the front end of the bottom plate 62, side plates 64 and 64 closing the left and right of the bottom plate 62, and an open state. And a flange 65 provided at the edge of the oblique side. The flange 65 is joined to the bottom surface 26a of the front side extension 26 by welding.

Inside the bracket 61, a partition wall 66 and a collar 67 are provided.
The partition wall 66 is, for example, a bent product of a steel plate, and has a horizontal plate 66a positioned on the bottom plate 62 with a certain distance D1 (first distance D1), and a bottom plate from the rear end of the horizontal plate 66a. It is a member having a substantially L-shape in a side view, which is composed of a vertical plate 66b extending to 62, and is joined to the inner surface of the bracket 61 by welding.
The collar 67 (distance piece 67) is a cylindrical member interposed between the bottom plate 62 of the bracket 61 and the horizontal plate 66a of the partition wall 66, and extends in the vertical direction. As described above, the collar 67 is provided in a closed cross section surrounded by the bracket 61 and the partition wall 66, and is formed of, for example, a steel pipe.

  The support member 71 is, for example, a bent product of a steel plate, and has a substantially U-shaped cross section when the vehicle body 11 (see FIG. 1) is viewed from the front. The support member 71 has a substantially horizontal bottom plate 72 and left and right sides of the bottom plate 72. Side plates 73 and 73 extending upward. The support member 71 has upper open ends 73a and 73a, that is, upper portions 73a and 73a of the left and right side plates 73 and 73, removably coupled to the side plates 64 and 64 of the bracket 61 by a plurality of bolts and nuts 74, respectively. Yes. The plurality of bolts and nuts 74 are preferably located between the bottom plate 62 and the lateral plate 66a.

  The bolt 81 extends upward from the bottom of the support member 71 through the bottom plate 72, further extends upward through the bottom plate 62, the collar 67 and the lateral plate 66 a of the bracket 61, and a nut 82 is fastened to the upper end thereof. It is. That is, the bolt 81 and the nut 82 are provided so as to penetrate the bracket 61 and the support member 71 in the vertical direction and tighten the bracket 61 and the support member 71 in the vertical direction.

  Further, the bolt 81 is provided with a washer 83 having a large outer diameter integrally or separately. The nut 82 is also provided with a washer 84 having a large outer diameter integrally or separately. For this reason, the load at the portion where the bracket 61 and the support member 71 and the bolts and nuts 81 and 82 are in contact with each other can be efficiently dispersed by the large washers 83 and 84. Therefore, the rear end portion 32 of the subframe 30 can be more reliably restricted from dropping downward from the front side extension portion 26. The nut 82 and the washer 84 are preferably joined to the horizontal plate 66a.

  Since the bracket 61 and the partition wall 66 constitute a closed cross-sectional body and the collar 67 is interposed between the bottom plate 62 and the lateral plate 66a, the load applied from the bolts and nuts 81 and 82 can be sufficiently supported. . About the 1st space | interval D1, it is set to the magnitude | size which can fully support the upper part of the volt | bolt 81 with the baseplate 62 and the horizontal board 66a.

  As is clear from the above description, there is a constant distance D2 (second distance D2) between the bottom surface 62a of the bracket 61 and the bottom plate 72 of the support member 71. Therefore, a space Sp (mount space Sp) surrounded by the bottom surface 62a of the bracket 61 and the bottom plate 72 and the left and right side plates 73, 73 of the support member 71 is provided below the bracket 61. The mount space Sp is open in the longitudinal direction of the vehicle body, and is positioned with the rear end portion 32 of the subframe 30 and the elastic bushing 50 inserted.

  The configuration of the elastic bushing 50 may be a known one for mounting a subframe on a general body frame, and will be described below with an example. In other words, the elastic bush 50 is composed of elastic bush members 51 and 51 which are divided into upper and lower parts. Each of the upper and lower elastic bush members 51, 51 is a vibration isolating member having a configuration in which an inner cylinder 52 and an outer cylinder 53 surrounding the inner cylinder 52 are connected by an elastic member 54 such as rubber (anti-vibration rubber). is there.

The elastic bush members 51, 51 divided into upper and lower parts are fitted into the through holes 33 in the rear end portion 32 of the subframe 30, and are then attached to the bracket 61 and the support member 71 by the bolts 81 penetrating the inner cylinders 52, 52. Mounted.
The configuration of the front elastic bush 50 attached to the front end portion 31 of the subframe 30 shown in FIG. 2 is basically the same as that of the rear elastic bush 50, and thus the description thereof is omitted.

  As shown in FIG. 3, the overall dimensions of the two inner cylinders 52, 52 that are vertically stacked substantially coincide with each other with respect to the second distance D <b> 2. Therefore, in the inner cylinders 52 and 52 located in the mount space Sp, the upper end surface is in contact with the bottom surface 62 a of the bracket 61, and the lower end surface is in contact with the upper surface of the bottom plate 72 of the support member 71.

  As described above, the bottom surface 62a of the bracket 61, the bottom plate 72 and the left and right side plates 73 and 73 of the support member 71 are configured to surround the rear end portion 32 of the subframe 30 and the elastic bush 50 and to be sandwiched vertically. The bolt 81 is configured to attach the rear end portion 32 and the elastic bush 50 of the subframe 30 to the bracket 61 and the support member 71 by penetrating the inner cylinders 52 and 52 vertically and tightening the nut 82. For this reason, the coupling mechanism 60 can be attached to the front side extension 26 while enclosing the rear end 32 and the elastic bushing 50 of the subframe 30 so as to restrict the downward drop from the front side extension 26. . Hereinafter, the elastic bushing 50 is referred to as “elastic body 50” as appropriate.

Next, the operation of the first embodiment having the above configuration will be described.
As shown in FIG. 3, if only the upper end portion (the end portion on the screwing side of the nut 82) of the bolt 81 is supported by the bracket 61, the cantilever is supported. On the other hand, the first embodiment is characterized by a so-called both-end support structure that supports both upper and lower ends of the bolt 81.

  Specifically, as described above, the upper end portion of the bolt 81 is directly supported by the bracket 61. Further, the lower end portion of the bolt 81 (the end portion on the head side of the bolt 81) is supported by the bracket 61 via the support member 71. As a result, the bolt 81 is supported by both end supports. The bolt 81 has a higher bending strength than that of a cantilever support structure. Moreover, both ends of the bolt 81 are supported very stably.

  In addition, the left and right side plates 73, 73 in the support member 71 are vertical plates whose plate surfaces face the vehicle width direction. Such a support member 71 has particularly high bending rigidity in the longitudinal direction of the vehicle body. When collision energy acts on the subframe 30 from the front, the collision energy can be sufficiently received by the bracket 61 and the support member 71.

  Further, the rear end portion 32 of the subframe 30 and the elastic bushing 50 are surrounded by the bottom surface 62a of the bracket 61, the bottom plate 72 and the left and right side plates 73, 73 of the support member 71, and are sandwiched vertically.

  For this reason, when the collision energy acts on the front surface of the vehicle body 11, the rear end portion 32 of the subframe 30 and the rear elastic body 50 are sufficiently restricted from dropping downward from the front side extension portion 26. The

FIG. 6 shows the transmission of collision energy that has acted on the front of the vehicle 10.
As shown in FIG. 6A, when the collision energy E1 acts on the bumper 25 from the front, the collision energy E1 is subtracted from the front side frame 21 as indicated by the solid arrow R1 shown in FIG. It is also distributed to the frame 30 and is transmitted from both the front side frame 21 and the sub frame 30 to the floor frame 27 through the front side extension 26.

  Further, as shown in FIG. 6A, when the collision energy E2 acts on the front end of the subframe 30 from the front, the collision energy E2 is reduced to the front as indicated by the broken arrow R2 shown in FIG. It is also distributed to the side frame 21, and is transmitted from both the front side frame 21 and the sub frame 30 to the floor frame 27 via the front side extension 26.

Thus, the collision energy E1, E2 can be efficiently transmitted from the subframe 30 to the floor frame 27 via the front side extension 26, and the subframe 30 itself can also absorb the collision energy E1, E2. Can do.
Moreover, since the collision energy E2 can be received even though the subframe 30 is located behind the bumper 25, for example, even when a vertical collision with the opponent vehicle occurs, it can be dealt with. .

  FIG. 7 shows the action of the vehicle body 11 due to the collision energy E <b> 1 acting on the front surface of the vehicle 10. As shown in FIG. 7A, consider the case where the collision energy E1 acts on the bumper 25 from the front. The collision energy E1 is distributed from the front side frame 21 to the subframe 30 and transmitted by the distribution energy E11. Accordingly, the collision energy E12 transmitted from the front side frame 21 to the floor frame 27 via the front side extension 26 decreases (E12 = E1-E11).

  In the case of Embodiment 1 shown in FIG. 7B, as described above, the rear end portion 32 of the subframe 30 and the rear elastic body 50 are sufficiently restricted from dropping downward from the front side extension portion 26. Has been. Therefore, the distributed energy E11 is efficiently transmitted from the sub frame 30 to the floor frame 27 via the front side extension 26.

  Since the collision energy E12 transmitted from the front side frame 21 to the front side extension 26 is small, the moment M1 at which the rear end 21a of the front side frame 21 tends to bend toward the vehicle compartment 13 can be small. As a result, the displacement amount X1 by which the dashboard 28 is displaced toward the passenger compartment 13 is small.

  On the other hand, in the comparative example shown in FIG. 7C, the rear end portion 32 of the sub frame 30 drops off from the front side frame 21 when a certain amount of collision energy acts on the front side frame 21. And fall. For this reason, since the collision energy E1 transmitted from the front side frame 21 to the front side extension 26 is large, the moment M2 at which the rear end 21a of the front side frame 21 tries to bend toward the passenger compartment 13 is large (M2> M1). . As a result, the displacement amount X2 by which the dashboard 28 is displaced toward the passenger compartment 13 is large (X2> X1).

  Thus, according to the structure of Example 1 shown in FIG.7 (b), a passenger | crew's protection performance can be improved further compared with the comparative example shown in FIG.7 (c).

The above description is summarized as follows.
In the first embodiment, as shown in FIGS. 3 and 6, the rear end portion 32 of the subframe 30 and the rear elastic body 50 are attached to the front side extension portion 26 by a connecting mechanism 60. The coupling mechanism 60 surrounds the rear end portion 32 of the subframe 30 and the rear elastic body 50 so as to restrict the downward drop from the front side extension portion 26.

  For this reason, when the collision energy E1, E2 acts on the front surface of the vehicle body 11, the rear end portion 32 of the subframe 30 is restricted from dropping downward from the front side extension portion 26. Therefore, since the sub frame 30 can be firmly connected to the front side frame 21 and the front side extension 26, the collision energy can be efficiently absorbed by the sub frame 30.

  That is, when the vehicle body 11 receives the collision energy E1, E2, the subframe 30 can be used as a collision energy absorbing member. Furthermore, the collision energy E1, E2 can be reliably and efficiently transmitted from the rear end portion 32 of the subframe 30 to the floor frame 27 via the front side extension portion 26. As a result, the occupant protection performance when the collision energy E1, E2 acts on the vehicle body 11 can be further enhanced.

  In addition, since the vehicle body 11 has a simple configuration in which the connection mechanism 60 is provided, and the subframe 30 is used as a collision energy absorbing member, it is not necessary to provide another member for absorbing the collision energy. For this reason, the increase in the weight of the vehicle body 11 can be suppressed as much as possible. Therefore, it is extremely advantageous in increasing the fuel consumption of the vehicle 10.

  Furthermore, a so-called floating attachment structure is adopted in which the sub frame 30 is attached to the front side frame 21 via the elastic body 50. Accordingly, during traveling of the vehicle 10, vibrations transmitted from the wheels to the subframe 30 via the suspension 43 (see FIG. 1), and vibrations transmitted from the engine 41 (see FIG. 1) to the subframe 30 via the elastic body. Is relieved by the elastic body 50 and is not easily transmitted to the passenger compartment 13. For this reason, vibration and noise transmitted to the passenger compartment 13 can be suppressed, and the ride comfort and comfort of the occupant can be enhanced.

  As described above, in the first embodiment, (1) vibration and noise transmitted to the passenger compartment 13 are suppressed to improve the ride comfort and comfort of the passenger, and (2) the collision energy E1, E2 is applied to the vehicle body 11. It is possible to make it possible to improve the protection performance of the occupant when acted.

  Next, Example 2 will be described with reference to FIGS. In addition, about the structure similar to the structure shown in the said FIGS. 1-5, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The front side extension 126 of the second embodiment has a closed cross-sectional structure and has substantially the same configuration as the front side extension 26 of the first embodiment shown in FIGS. The front side extension 126 according to the second embodiment is characterized in that the front surface 126a is configured as a vertical flat surface, and an insertion port 126b having a substantially rectangular shape (including a square) in front view is opened on the front surface 126a. To do. The rear end portion 32 and the elastic bushing 50 of the sub frame 30 are attached to the front side extension 126 by a connecting mechanism 160.

  The coupling mechanism 160 is configured to be attached to the front side extension 126 while enclosing the rear end portion 32 of the subframe 30 and the rear elastic bushing 50 so as to restrict downward dropping from the front side extension 126. The connecting mechanism 160 includes an insertion port 126b, a bracket 161, a bolt 181 and a nut 182.

  The bracket 161 is a member having a substantially U-shaped cross section with the front opened when the vehicle body 11 is viewed from the side. The bracket 161 is, for example, a bent product of a steel plate, and includes an upper plate 162, a lower plate 163, a vertical plate 164, and a flange 165.

  The upper plate 162 is a substantially horizontal flat plate that extends from the upper edge 126c of the insertion port 126b to the rear of the vehicle body and is provided inside the front side extension 126. The lower plate 163 is a substantially horizontal flat plate that extends from the lower edge 126d of the insertion port 126b toward the rear of the vehicle body and is provided inward of the front side extension 126. The vertical plate 164 is a vertical flat plate that connects at least the rear ends of the upper plate 162 and the lower plate 163. The flange 165 is provided at the front ends of the upper plate 162 and the lower plate 163.

  Such a bracket 161 is inserted into the front side extension 126 through the insertion port 126b, and the flange 165 is attached to the front 126a by being overlapped with the front 126a of the front side extension 126 and joined by welding. It is done. In addition, it is more preferable that the left and right sides of the bracket 161 are respectively closed by vertical plates.

  A collar 166 (a distance piece 166) is interposed between the bottom plate 126e of the front side extension 126 and the lower plate 163. The collar 166 is a cylindrical member extending in the vertical direction, and is made of, for example, a steel pipe.

  The bolt 181 extends upward from below the front side extension 126 through the bottom plate 126e, further extends upward through the lower plate 163 and the upper plate 162 of the collar 166 and the bracket 161, and a nut 182 at the upper end thereof. It has been concluded. That is, the bolt 181 and the nut 182 are provided so as to penetrate the upper plate 162 and the lower plate 163 in the vertical direction and tighten the upper plate 162 and the lower plate 163 in the vertical direction.

  Furthermore, the bolt 181 is provided with a washer 183 having a large outer diameter integrally or separately. The nut 182 is also provided with a washer 184 having a large outer diameter integrally or separately. For this reason, the load in the part which the front side extension part 126, the bracket 161, and the volt | bolt nuts 181 and 182 contact mutually can be efficiently disperse | distributed by the large washers 183 and 184. Therefore, the rear end portion 32 of the subframe 30 can be more reliably restricted from dropping downward from the front side extension 126. Note that the nut 182 and the washer 184 are preferably joined to the upper plate 162.

  As is clear from the above description, in the bracket 161, the upper plate 162 and the lower plate 163 have a constant interval D2 (second interval D2). For this reason, the bracket 161 has a space portion Sp (mount space portion Sp) surrounded by the upper plate 162 and the lower plate 163. The mount space Sp is open to the front side of the vehicle body, and the rear end portion 32 of the subframe 30 and the elastic bush 50 are located.

  The configuration of the elastic bush 50 (elastic body 50) is the same as that of the elastic bush 50 of the first embodiment. In the inner cylinders 52 and 52 located in the mount space Sp, the upper end surface is in contact with the upper plate 162 and the lower end surface is in contact with the lower plate 163.

  As described above, the coupling mechanism 160 is configured to insert the rear end portion 32 of the subframe 30 and the elastic bushing 50 into the insertion port 126b, and surround the upper frame 162 and the lower plate 163 and sandwich them vertically. The bolt 181 has a configuration in which the rear end portion 32 and the elastic bush 50 of the sub frame 30 are attached to the upper plate 162 and the lower plate 163 by penetrating the inner cylinders 52, 52 vertically and tightening the nut 182. For this reason, the coupling mechanism 160 can be attached to the front side extension 126 while enclosing the rear end portion 32 and the elastic bushing 50 of the subframe 30 so as to restrict the downward drop from the front side extension 126. .

Next, the operation of the second embodiment having the above configuration will be described.
The second embodiment is characterized by a so-called both-end support structure that supports both upper and lower ends of the bolt 181. Specifically, as described above, the upper end portion of the bolt 181 is directly supported by the upper plate 162 of the bracket 161. The lower end of the bolt 181 (the end on the head side of the bolt 181) is supported by the lower plate 163 of the bracket 161 and the bottom plate 126e of the front side extension 126. As a result, the bolt 181 is supported by both end supports. The bolt 181 has higher bending strength than the cantilever support structure. In addition, both ends of the bolt 181 are supported extremely stably.

Further, the rear end portion 32 and the elastic bushing 50 of the subframe 30 are surrounded by the upper plate 162 and the lower plate 163 of the bracket 161 and are sandwiched vertically.
For this reason, when the collision energy acts on the front surface of the vehicle body 11, the rear end portion 32 of the subframe 30 and the rear elastic body 50 are sufficiently restricted from dropping downward from the front side extension 126. The Therefore, the collision energy can be efficiently transmitted from the rear end portion 32 of the subframe 30 to the floor frame 27 via the front side extension 126.

  Furthermore, in the second embodiment, the elastic body 50 after being inserted from the insertion port 126b is surrounded and sandwiched vertically by the upper plate 162 and the lower plate 163 provided inside the front side extension 126. This constitutes a so-called floating mounting structure. Accordingly, vibrations transmitted from the wheels to the subframe 30 via the suspension 43 and vibrations transmitted from the engine 41 to the subframe 30 via the elastic body 50 while the vehicle 10 is traveling are mitigated by the elastic body 50. Therefore, it is difficult to be transmitted to the passenger compartment 13. For this reason, vibration and noise transmitted to the passenger compartment 13 can be suppressed, and the ride comfort and comfort of the occupant can be enhanced.

  Accordingly, in the second embodiment, as in the first embodiment, (1) vibration and noise transmitted to the passenger compartment 13 are suppressed, and passenger comfort and comfort are increased. It is possible to make it possible to improve the occupant's protection performance when collision energy acts on the vehicle.

In the present invention, the subframe 30 may be configured to support at least one of the power source 41 and the suspension 43.
Moreover, the power source 41 should just generate | occur | produce the motive power for driving | running | working, and may be an electric motor other than an engine, for example.

  The vehicle body structure of the present invention is suitable for use in an automobile in which the subframe 30 supporting the power source 41 and the suspension 43 is attached to the vehicle body frame 20 via the elastic body 50.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Vehicle body, 20 ... Body frame, 21 ... Front side frame, 21a ... Rear end, 26 ... Front side extension part, 27 ... Floor frame, 30 ... Sub-frame, 31 ... Front end part, 32 ... Rear end 50, elastic body (elastic bushing for vibration isolation), 60, coupling mechanism, 61, bracket, 62a, bottom surface of the bracket, 71, support member, 73a, open end on top, 81, bolt, 82, nut. 83, 84 ... Washers, 126 ... Front side extension, 126a ... Front surface of front side extension, 126b ... Insert, 160 ... Connection mechanism, 161 ... Bracket, 162 ... Upper plate, 163 ... Lower plate, 164 ... Vertical plate 181 ... bolts, 182 ... nuts, 183,184 ... washers, Sp ... mount space.

Claims (3)

The left and right front side frames extending forward and backward at the front portion of the vehicle body are connected to the front end portion and the rear end portion of the sub-frames disposed below the front side frames via the front elastic body and the rear elastic body, respectively. In the body structure that is designed to be installed,
The rear ends of the left and right front side frames are joined to the floor frame via a front side extension that extends rearward and downward,
The front side extension is configured to attach the rear end portion of the subframe and the rear elastic body by a coupling mechanism,
The coupling mechanism is configured to attach to the front side extension while enclosing the rear end portion of the subframe and the rear elastic body so as to restrict the downward drop from the front side extension ,
The coupling mechanism includes a bracket provided on the front side extension, a support member having a substantially U-shaped cross section when viewed from the front of the vehicle body, the open end of which is connected to the bracket, and the bracket and the support member. And the bolts and nuts provided to tighten the bracket and support member up and down,
Surrounding the rear end portion of the subframe and the rear elastic body by the bottom surface of the bracket and the support member and sandwiching the subframe in the vertical direction,
The rear end of the subframe and the rear elastic body were attached to the bracket and the support member by vertically passing the bolt through the rear elastic body.
Body structure characterized by that. The left and right front side frames extending forward and backward at the front portion of the vehicle body are connected to the front end portion and the rear end portion of the sub-frames disposed below the front side frames via the front elastic body and the rear elastic body, respectively. In the body structure that is designed to be installed,
The rear ends of the left and right front side frames are joined to the floor frame via a front side extension that extends rearward and downward,
The front side extension is configured to attach the rear end portion of the subframe and the rear elastic body by a coupling mechanism,
The coupling mechanism is configured to attach to the front side extension while enclosing the rear end portion of the subframe and the rear elastic body so as to restrict the downward drop from the front side extension,
The coupling mechanism includes a bracket provided on the front side extension, a support member having a substantially U-shaped cross section when viewed from the front of the vehicle body, the open end of which is connected to the bracket, and the bracket and the support member. And the bolts and nuts provided to tighten the bracket and support member up and down,
Surrounding the rear end portion of the subframe and the rear elastic body by the bottom surface of the bracket and the support member and sandwiching the subframe in the vertical direction,
The rear end of the subframe and the rear elastic body were attached to the bracket and the support member by vertically passing the bolt through the rear elastic body.
Body structure characterized by that. The bolt is provided with a washer having a large outer diameter integrally or separately, and the nut fastened to the bolt is also provided with a washer having a large outer diameter integrally or separately. The vehicle body structure according to claim 1 or 2, wherein

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