JP6732377B2 - Vehicle frame structure - Google Patents

Description

The present invention relates to a vehicle frame structure.

FIG. 7 shows the structure of the rear portion of the chassis frame 1 in a conventional heavy-duty transportation vehicle such as a bus. This type of chassis frame 1 includes a pair of left and right side rails 2 and 2 extending in the vehicle front-rear direction, and a plurality of cross members (the rear end in FIG. 7) connecting the side rails 2 and 2 in the vehicle width direction at a plurality of positions in the vehicle front-rear direction. Cross member 3 and only the second and third cross members 4 and 5 from the last end).

An engine 6 is mounted between the rearmost cross member 3 and the third cross member 5, and the engine 6 includes engine mount brackets (front engine mounts) attached to the left and right of the second cross member 4. Brackets 7 and 7 and engine mount brackets (rear engine mount brackets) 8 and 8 mounted on the side rails 2 and 2 between the cross member 3 and the cross member 4, respectively. Is fixed between.

Reference numeral 9 in FIG. 7 denotes an exhaust gas purification device, 10 denotes a radiator, and 11 denotes a rear axle.

As a document showing a general technical level regarding the frame structure of this type of vehicle, there are, for example, the following Patent Documents 1 and 2.

JP, 2010-149752, A Japanese Utility Model Publication No. 62-48833

The structure for supporting the engine 6 by the chassis frame 1 is required to have not only strength for supporting the weight of the engine 6 but also torsional rigidity capable of sufficiently suppressing vibration accompanying the operation of the engine 6. Since the space between the rearmost cross member 3 and the second cross member 4 is occupied by the engine 6, the left and right side rails 2, 2 may be directly connected to each other. However, it is difficult to increase the rigidity of the rear portion of the chassis frame 1.

On the other hand, in recent years, the exhaust emission control device 9 tends to increase in size due to measures against environmental standards that are becoming stricter year by year. In addition, the radiator 10 is inevitably increased in size with the increase in the output of the engine 6, and when a turbocharger (not shown) mounted on the engine 6 is a two-stage supercharger, This also requires a large installation space. Under these circumstances, it is becoming more and more difficult to secure the strength and rigidity of the chassis frame 1 while installing these devices in a certain space.

In view of such circumstances, the present invention is to provide a frame structure of a vehicle capable of ensuring mountability of an engine and peripheral devices without impairing the rigidity of the chassis frame.

The present invention is a frame structure of a vehicle in which an engine is mounted between left and right side rails connected by a cross member, and one side is provided near an engine mount bracket that connects the left and right side rails and the engine. The cross-sectional dimension of the rail is smaller than the cross-sectional dimension of the other side rail, and a support beam that connects the left and right side rails is attached near the engine mount bracket. It relates to the frame structure of a vehicle.

Thus, in this way, the rigidity of the other side rail having a large cross-sectional dimension is transmitted to the one side rail via the support beam, and sufficient rigidity is secured even on the side rail having a small cross-sectional dimension. be able to.

In the frame structure of a vehicle of the present invention, the one side rail is configured by including flanges above and below a web that forms a vertical plane along the vehicle body direction, and one end side of the support beam has one side rail of the one side rail. The lower surface of the other side rail is connected to the one side rail via a support beam bracket that is connected to a web forming a side surface and has a lower surface connected to one end side of the support beam. It is preferable that the support beam is connected to the side rail, and the rigidity of the other side rail is surely transmitted to the one side rail side through the support beam, while facilitating the removal of the support beam from the side rail. be able to.

In the vehicle frame structure of the present invention, it is preferable to provide a box portion having a closed cross section in the attachment portion of the engine mount bracket on the other side rail and the connection portion with the support beam. The box part having high rigidity can support the engine mount bracket, and the rigidity of the box part can be transmitted to one side rail side via the support beam.

According to the vehicle frame structure of the present invention, various excellent effects as described below can be obtained.

(I) According to the first aspect of the present invention, since the rigidity of the other side rail having a large cross-sectional dimension is transmitted to the side rail having the small cross-sectional dimension, the rigidity of the chassis frame is not impaired. The mountability of the engine and peripheral devices can be secured.

(II) According to the second aspect of the present invention, even if one of the side rails is designed to have a small dimension in the width direction, the rigidity of the other side rail is reliably transmitted to the one side rail side. As a result, the rigidity of the chassis frame as a whole can be secured, and the support beam can be easily removed to maintain workability during maintenance and the like.

(III) According to the invention described in claim 3 of the present invention, the high rigidity of the box portion can be transmitted to one side rail side, and the rigidity of the entire chassis frame can be more reliably maintained.

FIG. 1 is a plan view showing an example (embodiment) of a vehicle frame structure according to an embodiment of the present invention. It is sectional drawing of each part of the side rail in the Example of this invention, (A) is a IIA-IIA arrow equivalent view of FIG. 1, (B) is a IIB-IIB arrow equivalent view of FIG. 1, (C) is It is an IIC-IIC arrow equivalent figure of FIG. It is the perspective view which looked at the example of the present invention from the slanting lower part. It is sectional drawing which shows the principal part of the Example of this invention, and is an IV-IV arrow equivalent view of FIG. It is a figure which shows the support beam used for the Example of this invention, (A) is a front view, (B) is a top view, (C) is a side view. It is a figure which shows the support beam bracket used for the Example of this invention, (A) is a front view, (B) is a top view, (C) is a side view. It is a top view which shows an example of the conventional frame structure of a vehicle.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 6 show an example of a form of a frame structure of a vehicle according to an embodiment of the present invention. In the drawings, portions denoted by the same reference numerals as those in FIG. This is similar to the conventional one shown in FIG.

The chassis frame 12 shown here is a pair of left and right connected to each other by a plurality of cross members (here, only the cross members 3, 4 and 5 on the rear side of the vehicle are shown), as in the conventional example (see FIG. 7). Although the engine 6 is mounted between the side rails 13 and 14, in the present embodiment, one side rail 13 is cut at a position immediately after the third cross member 5, and this position (cut position) is set. The rear side is configured as a small cross section 13a. In other words, the one side rail 13 is composed of a small cross-section portion 13a rearward from the cut position and a large cross-section portion 13b frontward from the cut position.

At the cut position, the outer side in the vehicle width direction of the rear end of the large cross section 13b and the inner side in the vehicle width direction of the front end of the small cross section 13a face each other through welding, fastening or the like via a bracket (not shown). Both are connected by means. That is, the small cross section 13a is arranged so as to be offset outward from the large cross section 13b by the lateral width of the large cross section 13b.

The large cross-section 13b and the other side rail 14 are designed to have the same cross-sectional dimensions as the side rail 2 of the conventional example (see FIG. 7), but the small cross-section 13a has the large cross-section 13b and the other side. It is designed to have a smaller cross-sectional dimension than the rail 14.

Specifically, as shown in FIGS. 2A to 2C, the small cross-section portion 13a and the large cross-section portion 13b forming one side rail 13 and the other side rail 14 are vertically arranged along the vehicle body direction. It is configured to have a lateral U-shaped cross section in which flanges projecting inward in the vehicle width direction are arranged above and below a surface web, and the small cross-section portion 13a includes the upper and lower flanges in the vehicle width direction. Is shorter than the large cross section 13b and the other side rail 14, and is designed to have a small dimension in the width direction.

The positions and the cross-sectional dimensions of the small cross-section portion 13a are a configuration for appropriately laying out these devices on the chassis frame 12 according to the enlargement of the devices such as the exhaust emission control device 9 and the radiator 10. That is, since the equipment around the installation position of the engine 6 is originally crowded and individual equipment is also becoming larger, in order to secure an installation space for these equipment, the side rail 13 of the side rail 13 is provided in the vicinity of the engine 6. The cross-sectional dimensions are made smaller and the positions are shifted. Further, in order to secure workability at the time of assembly and maintenance, it is necessary to cut out the flanges forming the side rails 13 and 14 at appropriate places.

On the other hand, the periphery of the engine 6 is also a portion of the chassis frame 12 which is particularly required to have strength and rigidity. Above all, since the vibration from the engine 6 is directly transmitted to the vicinity of the rear engine mount brackets 8 and 8 on which the engine 6 is mounted, the side rails 13 and 14 require particularly high torsional rigidity at this position. .. However, when the side rails 13 near the rear engine mount brackets 8 and 8 are configured as the small cross-section portion 13a having a short cross-sectional shape as in the present embodiment, the torsional rigidity of the side rails 13 decreases at this portion. It cannot be avoided.

Therefore, in the present embodiment, the support beam 15 is stretched over a position near the rear engine mount brackets 8 and 8 between the rearmost cross member 3 and the second cross member 4 of the pair of side rails 13 and 14. The side rails 13 and 14 are connected to each other so that the rigidity of the other side rail 14 having a large cross-sectional dimension is transmitted to the one side rail 13. By doing so, sufficient rigidity can be ensured even on the side rail 13 side having a small cross-sectional dimension, and torsional rigidity of the chassis frame 12 as a whole can be ensured.

A specific configuration of the support beam 15 and the connection structure by the support beam 15 will be described below. As shown in FIGS. 3 and 4, the support beam 15 is arranged so as to bridge between the lower surface of the one side rail 13 and the lower surface of the other side rail 14, but with respect to the other side rail 14. While the ends are directly connected, one side rail 13 is connected via a support beam bracket 16.

As shown in FIG. 5, the support beam 15 is provided with connecting portions 18 at both ends of a pipe 17 extending in the vehicle width direction. Each connecting portion 18 is a suspending tool 18a that suspends and supports the end portion of the pipe 17 from the lower surface (see FIGS. 3 and 4) of the support beam bracket 16 or the side rail 14, and the suspending tool 18a and the pipe 17. It is provided with a reinforcing plate 18b that reinforces the connection structure with the end portion. The suspending tool 18a is formed by bending a steel plate into an L shape, is orthogonal to the pipe 17 in the vicinity of the end of the pipe 17, and has a vertical lower surface that penetrates the end of the pipe 17 and forms a vertical plane. 18 c, and a connecting surface 18 d that bends inward in the vehicle width direction from the hanging lower surface 18 c and extends upward to form a horizontal plane above the pipe 17. The penetrating portion of the pipe 17 on the hanging lower surface 18c is welded to the outer periphery of the pipe 17. The connecting surface 18d is provided with a plurality of holes 18e, and is fastened to the lower surface of the support beam bracket 16 or the lower surface of the side rail 14 through fasteners 19 such as bolts and nuts in the holes 18e (FIGS. 3 and 4). reference).

The reinforcing plate 18b has a vertical plane orthogonal to the hanging lower surface 18c and the connecting surface 18d, and two reinforcing plates 18b are provided for each connecting portion 18. The two reinforcing plates 18b are arranged so as to sandwich the ends of the pipe 17 from both sides along the direction of the pipe 17. The upper edge 18f of the reinforcing plate 18b has a shape along the lower surface side of the connecting surface 18d formed by the hanging tool 18a and is welded to the connecting surface 18d, and the outer edge 18g on the vehicle width direction outer side is the vehicle width direction of the hanging lower surface 18c. It is welded to the hanging lower surface 18c in a shape along the inner surface. The lower edge 18h of the reinforcing plate 18b is in contact with the surface of the pipe 17 along the direction of the pipe 17, and is welded to the pipe 17. In this way, the two reinforcing plates 18b reinforce the connection between the suspension 18a and the end of the pipe 17, thereby strengthening the overall structure of the connecting portion 18.

As shown in FIG. 6, the support beam bracket 16 includes a first connecting surface 16a that forms a vertical surface on the inner side in the vehicle width direction and a horizontal surface that extends outward from the vehicle width direction while bending from the lower side of the first connecting surface 16a. And a second connecting surface 16b forming The first connecting surface 16a and the second connecting surface 16b are combined to form an L-shaped cross-sectional shape, and a reinforcing plate 16c forming a vertical plane orthogonal to the first connecting surface 16a and the second connecting surface 16b is connected between them. And is reinforced. A plurality of holes 16d for fastening are formed in each of the first connecting surface 16a and the second connecting surface 16b. Then, the first connecting surface 16a is connected to the web forming the side surface of the one side rail 13 from the outside in the vehicle width direction by a fastener 19, and the second connecting surface 16b is supported on the lower surface. The connecting member 18d is connected to the connecting surface 18d of the beam 15 by a fastener 19 so as to face the connecting surface 18d (see FIG. 4).

In addition, a positioning portion 16e that is provided at an end portion of the second connecting surface 16b on the outer side in the vehicle width direction and that protrudes downward in a vertical plane orthogonal to the vehicle width direction is provided. When attaching one end of the support beam 15 to the support beam bracket 16 (see FIGS. 3 and 4), the one end side of the pipe 17 is abutted against the positioning portion 16e, so that the second connecting face 16b is connected to the connecting face. 18d can be easily positioned. Here, the lower end of the positioning portion 16e is bent toward the inner side in the vehicle width direction, and by inserting this portion into the tip of the pipe 17 (see FIGS. 3 and 4) at the time of assembly, positioning can be performed more easily. You can do it.

With such a structure, as shown in FIG. 4, one end of the support beam 15 is fixed to the second connecting surface 16b of the support beam bracket 16 attached to the side rail 13, and the other end is fixed to the flange of the side rail 14. .. By fixing the pipe 17 by suspending it from the support beam bracket 16 or the suspension 18a connected to the lower surface of the side rail 14, the support beam 15 as a whole goes around from both side rails 13 and 14 to the lower side. The support beam 15 can connect the side rails 13 and 14 to each other while avoiding interference with the engine 6. The degree to which the support beam 15 turns around from the side rails 13 and 14 to the lower side depends on the positional relationship between the engine 6 and the side rails 13 and 14, and the suspending tool 18a or the reinforcing plate 18b forming the connecting portion 18 is provided. It can be adjusted as appropriate by changing the vertical dimension of.

Further, as shown in FIG. 4, a U-shaped cross-sectional shape is formed in the vicinity of a portion of the other side rail 14 to which the support beam 15 is connected so as to face the U-shaped cross-sectional shape of the other side rail 14. The box portion 14b having the closed cross-sectional shape is assembled to the box portion 14b, and the box portion 14b has particularly high torsional rigidity. Since the rigidity is transmitted from the box portion 14b, which is a portion having high rigidity, to the small cross-section portion 13a of the side rail 13 via the support beam 15, sufficient rigidity is achieved even in the small cross-section portion 13a originally having low torsional rigidity. Can be secured.

Here, the one end side of the support beam 15 is connected to the side surface on the outer side in the vehicle width direction rather than the lower surface of the small cross-section portion 13a through the support beam bracket 16. As described above, the small cross-section portion 13a is designed to have a short dimension in the width direction, so that even if the support beam 15 is directly connected to the flange portion forming the lower surface, the rigidity of the other side rail 14 is sufficiently transmitted. It is not possible. For this reason, one end of the support beam 15 is connected to the web of the small cross section 13a via the support beam bracket 16 so that sufficient connection strength is maintained between the support beam 15 and the side rails 13.

Further, as described above, the connection position of the side rails 13 and 14 with the support beam 15 is in the vicinity of the rear engine mount brackets 8 and 8 and is a portion of the chassis frame 12 that requires particularly high rigidity. Further, the rear engine mount bracket 8 is attached to the box portion 14b provided on the other side rail 14 together with the support beam 15. That is, the box portion 14b forms a connecting portion with the support beam 15 and also constitutes a mounting portion for the rear engine mount bracket 8, and supports the rear engine mount bracket 8 on the other side rail 14 side with high rigidity. In addition, it also supports the vicinity of the rear engine mount bracket 8 on one of the side rails 13 via the support beam 15.

From the mechanical viewpoint as described above, it is not always necessary to connect the support beam 15 and the side rail 13 via the support beam bracket 16. For example, one end side of the support beam 15 itself has a shape extending upward while wrapping around the outside of the side rail 13 in the vehicle width direction (in other words, a shape in which the support beam 15 and the support beam bracket 16 are integrally formed. By doing so, it is possible to directly connect the support beam 15 and the side rails 13. However, in this case, workability at the time of assembling and dismounting is deteriorated, so that the support beam 15 and the support beam bracket 16 are configured as separate members as shown in FIG.

That is, when the support beam 15 or the support beam bracket 16 is connected to the side surface of the web forming the side rail 13, the fastener 19 is provided so as to penetrate the web of the side rail 13 in the horizontal direction. The fasteners 19 provided at different angles cannot be easily removed for maintenance or the like. On the other hand, when the support beam bracket 16 is attached to the web of the side rail 13 and the support beam 15 is connected to the lower surface of the support beam bracket 16 as in the present embodiment, the fastener 19 is located on one end side of the support beam 15. It is provided so as to vertically penetrate the upper surface and the lower surface of the support beam bracket 16. The fastener 19 in this position can be easily removed from below using a tool. Further, since the other end side of the support beam 15 is connected to the lower surface of the other side rail 14, the fastener 19 here can also be easily removed from below. When performing work such as maintenance, by removing the fasteners from both ends of the support beam 15, the support beam 15 can be removed and the engine 6 can be easily accessed. As described above, in this embodiment, by connecting the support beam 15 to the one side rail 13 via the support beam bracket 16, both the torsional rigidity is secured and the workability is achieved.

As described above, according to the present embodiment, the left and right side rails 13 are related to the frame structure of the vehicle in which the engine 6 is mounted between the left and right side rails 13, 14 connected by the cross members 3, 4, 5. , 14 and an engine mount bracket (rear engine mount bracket) 8 for connecting the engine 6 to each other, the cross-sectional dimension of one side rail 13 is smaller than the cross-sectional dimension of the other side rail 14, and Since the support beam 15 that connects the left and right side rails 13 and 14 is mounted near the engine mount bracket (rear engine mount bracket) 8 and 8, the rigidity of the other side rail 14 having a large cross-sectional dimension is supported. It can be transmitted to one of the side rails 13 via the beam 15, and sufficient rigidity can be secured even on the side rail 13 side having a small cross-sectional dimension.

In addition, in the present embodiment, one side rail 13 is configured by including flanges at the top and bottom of a web that forms a vertical plane along the vehicle body direction, and one end side of the support beam 15 has a side surface of the one side rail 13. Is connected to one of the side rails 13 via a support beam bracket 16 which is connected to the formed web and has a lower surface connected to one end side of the support beam 15, and the other end side of the support beam 15 is connected to the lower surface of the other side rail 14. Since they are connected, even if one of the side rails 13 is designed to have a small dimension in the width direction, the rigidity of the other side rail 14 is surely transmitted to the one side rail 13 side via the support beam 15 and thus the chassis is supported. The rigidity of the frame 12 as a whole can be secured, and further, the support beam 15 can be easily removed from the side rails 13 and 14, and the workability at the time of maintenance can be maintained.

Further, in the present embodiment, the box portion 14b having a closed cross section is provided at the attachment portion of the engine mount bracket (rear engine mount bracket) 8 on the other side rail 14 and the joint portion with the support beam 15. The box mount 14b having high rigidity supports the engine mount bracket (rear engine mount bracket) 8, and the rigidity of the box part 14b is transmitted to one side rail 13 side through the support beam 15 so that the chassis frame 12 as a whole. The rigidity can be maintained more reliably.

Therefore, according to the present embodiment described above, the mountability of the engine and peripheral devices can be secured without impairing the rigidity of the chassis frame.

The vehicle frame structure of the present invention is not limited to the above-described embodiment, and the same structure may be applied to the vicinity of the front engine mount bracket, and the front engine or mid engine type may be used. Needless to say, various modifications can be made without departing from the scope of the present invention, such as being applicable to the vehicle.

3 Cross member 4 Cross member 5 Cross member 6 Engine 8 Engine mount bracket (rear engine mount bracket)
13 Side rail (one side rail)
14 Side rail (other side rail)
14b Box part 15 Support beam 16 Support beam bracket

Claims (3)

A frame structure of a vehicle in which an engine is mounted between left and right side rails connected by a cross member, and a cross-sectional dimension of one side rail in the vicinity of an engine mount bracket connecting the left and right side rails and the engine. Is smaller than the cross-sectional dimension of the other side rail, and a support beam that connects the left and right side rails is mounted near the engine mount bracket. .. The one side rail includes flanges above and below a web that forms a vertical plane along the vehicle body direction, and one end side of the support beam is connected to a web that forms a side surface of the one side rail and has a lower surface. Is connected to the one side rail via a support beam bracket connected to one end side of the support beam, and the other end side of the support beam is connected to a lower surface of the other side rail. The frame structure for a vehicle according to claim 1. The frame structure for a vehicle according to claim 1 or 2, wherein a box portion having a closed cross section is provided at an attachment portion of the engine mount bracket on the other side rail and a connection portion with the support beam.

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