JP4158557B2 - Front suspension device for automobile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a front suspension device for an automobile.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a power steering device is mounted on a vehicle in order to reduce a steering force required for a driver's steering operation. In recent years, instead of the conventional hydraulic type, such an electric type using an electric motor has been adopted for such a power steering device, which reduces the engine load and contributes to the improvement of fuel consumption. (For example, see Patent Document 1 below).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 08-332964
[Problems to be solved by the invention]
Such an electric power steering device is generally attached to a suspension cross member that supports a front suspension and is provided at a lower portion of an engine room of a vehicle. However, when a wide tire is attached to the front for improving the vehicle performance, a large lateral force is input from the tire to the electric power steering device through the tie rod while the vehicle is running. At this time, particularly when the electric power steering device is a ball screw type, the rigidity is relatively low due to the fact that the electric power steering device is configured to be small and light in order to improve response and reduce power consumption. In some cases, the shaft in the power steering apparatus is deformed such as torsion due to a lateral force, resulting in an increase in friction and a target steering feeling cannot be obtained. Although such problems can be dealt with by increasing the cross-sectional area of the suspension cross member to which the power steering device is attached to increase the support rigidity of the power steering device, it is limited by the layout in the engine room of the vehicle. When the cross-sectional area of the suspension cross member cannot be secured, the suspension cross member itself is deformed by the lateral force from the tire applied via the power steering device, so the problem of the deterioration of the steering feeling described above is Inevitable.
[0005]
Therefore, in the above case, the steering feeling is not limited to the fact that the motor of the electric power steering apparatus has a large output and the assist of the steering force can be smoothly performed even if the electric power steering apparatus is slightly deformed. However, since this method requires a large amount of electric power and increases the load on the battery of the vehicle, a more preferable solution has been desired.
[0006]
The present invention has been made in view of the above problems, and the object of the present invention is to reinforce the mounting portion of the electric power steering device to the suspension cross member by a simple method in the front suspension device of an automobile. It is to prevent the deterioration of the steering feeling due to the deformation of the electric power steering device.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a front suspension device for an automobile including a suspension cross member to which a ball screw type electric power steering device is attached. The suspension cross member is provided below the engine and on the front side frame. It has a front and rear frame that is disposed below and extends in the vehicle width direction and is arranged in the vehicle front-rear direction, and has a substantially rectangular frame shape in a vehicle plan view. It is attached to the front side frame that extends upward in the vehicle front view and is arranged on the left and right sides of the vehicle with respect to the intermediate portion in the width direction, and the intermediate portion in the vehicle width direction of the front frame of the suspension cross member mounting seat is provided for fixing the electric power steering apparatus, the electric Pawasute The ring device, a plurality of mounting portions which are bolted to the mounting seat of the front frame of the suspension cross member is provided, the integrally has an attachment portion that corresponds to the respective mounting portion of the electric power steering apparatus reinforcement comprising a plate, the reinforcing plate includes a main body portion with the electric power steering device via the mounting portion of the reinforcing plate Ru are fastened together by bolts to the mounting seat of the front frame, respectively from both ends of the body portion An extension portion that extends outward in the vehicle width direction and is fixed to the left and right front side frames of the vehicle. The main body portion and the extension portion of the reinforcing plate correspond to the front frame in a vehicle front view. It has a shape .
[0008]
According to the above configuration, the electric power steering device is fixed to the suspension subframe with the bolt together with the reinforcing plate integrally having the attachment portion, so that the attachment portion of the electric power steering device is reinforced together with the suspension subframe. Reinforced by plates. Therefore, even if an external force from the tire is applied, the electric power steering device can be prevented from being deformed, and in particular, it is possible to prevent the deterioration of the steering feeling that is likely to occur in the case of a ball screw type electric power steering device. Moreover, such an effect can be realized with a simple structure in which the reinforcing plate is fastened together.
[0009]
Further, since the reinforcement plate is attached to the vehicle body frame via the extension portion in addition to the plurality of attachment portions, the reinforcement plate is more firmly fixed. Therefore, the reinforcing plate itself is prevented from being deformed or displaced to the maximum, and the steering feeling can be ensured more reliably.
[0010]
Further, since the electric power steering is attached to the front of the suspension cross member, the power train mounting position can be located further rearward. That is, there is a need to lay out the power train as far as possible in order to improve the motion performance of the vehicle, particularly in a vehicle having a front engine / rear drive (FR) drive configuration. At that time, in FR vehicles, it tends to be difficult to secure a space behind the power train in the engine room due to the vertical installation of the transmission. In addition, it is possible to secure the mounting location of the electric power steering device on the suspension cross member. Further, since the electric power steering device is attached to the front of the suspension cross member via the mounting seat and the suspension cross member is reinforced by the reinforcing plate, the vertical dimension of the suspension cross member can be made as small as possible. Therefore, the mounting height of the engine can be reduced, which contributes to increasing the degree of freedom in the appearance design of the vehicle.
[0011]
According to a second configuration of the present invention, the electric power steering device is provided with at least three attachment portions that are not arranged linearly, and the reinforcing plate corresponds to the attachment portion of the electric power steering. And at least three attachment portions.
[0012]
According to the above configuration, since the reinforcing plate and the attachment portion to the suspension cross member of the electric power steering apparatus are at least three, and they are not arranged linearly, the reinforcing plate is formed by the three attaching portions. Acts as a surface. Therefore, the reinforcing effect is surely exhibited even in the twisting direction, and the reinforcing effect by the reinforcing plate can be further enhanced.
[0013]
According to a third configuration of the present invention, the reinforcing plate has a bent portion along the longitudinal direction of the electric power steering device in a state where the reinforcing plate is fastened together with the suspension cross member together with the electric power steering device. It is.
[0014]
According to said structure, since a reinforcement plate has a bending part along the longitudinal direction of an electric power steering apparatus, the bending direction deformation | transformation of an electric power steering apparatus is prevented by a bending part.
[0015]
【The invention's effect】
According to the present invention, in the front suspension device of an automobile, the attachment part of the electric power steering device to the suspension cross member is reinforced by a simple method, thereby deteriorating the steering feeling due to the deformation of the electric power steering device. Can be prevented.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to FIGS.
[0017]
FIG. 1 is a schematic side view of a vehicle V to which a front suspension apparatus 10 according to the present invention is applied. The vehicle V is of a so-called front engine / rear drive type (FR), and a power train P including an engine E and a transmission T is mounted in an engine room EC formed in the front portion of the vehicle V. . The transmission T is mounted in a so-called vertical position immediately after the engine E, and the power train P occupies the front part of the vehicle compartment PC from the rear part of the engine room EC in a side view. Specifically, the power train P is mounted so as to be located behind the front axle, and the vehicle V is in the form of a so-called front midship.
[0018]
In the lower part of the engine E, the suspension cross member 1 is attached below the front side frame of the vehicle V (not shown). As will be described in detail later with reference to FIG. 2, the suspension cross member 1 includes a suspension arm 101 and a coil damper 102 that constitute the suspension device 10, and an electric power steering unit 2 (hereinafter referred to as a power steering unit) that will be described later. The front suspension device 10 is assembled in advance and is mounted on the vehicle V as a suspension unit. The power steering unit 2 is attached to the front surface of the suspension cross member 1 because the power train P occupies the rear part of the engine room EC as described above.
[0019]
Next, attachment of the power steering unit 2 to the suspension cross member 1 will be described with reference to FIG. FIG. 2 is an exploded perspective view of the suspension unit 10 including the suspension cross member 1, the power steering unit 2, and a reinforcing plate 3 described later, as viewed from the front side.
[0020]
As described above, the suspension cross member 1 includes the suspension arm 101, the coil damper 102, the wheel support 103, the brake disc 104, the brake caliper 105, the stabilizer 106, and the like as components constituting the suspension device 10 of the vehicle V. It is attached. The suspension cross member 1 has a substantially rectangular shape when viewed from above, and both sides of the front frame 11 extending in the vehicle width direction on the front side of the vehicle V are curved upward, and the attachment portion and the suspension to the front side frame A mounting portion of the arm 101 is configured. Further, on the front surface of the front frame 11 in the suspension cross member 1, two sets of two mounting seats 110 that are spaced apart in the vertical direction are provided spaced apart in the vehicle width direction, and a total of four mounting seats 110 are formed. Has been. That is, the suspension cross member 1 is formed with four mounting seats 110 that are not in a straight line. The mounting seat 110 is formed by protruding the front surface of the front frame 11 forward, and the power steering unit 2 and the reinforcing plate 3 are fixed as described later.
[0021]
On the other hand, the power steering unit 2 is of a ball screw type, and is provided with four through holes 20 as mounting portions corresponding to the mounting seats 110 formed on the front frame 11. In addition, tie rods 21 extending on the left and right sides of the power steering unit 2 are rotatably fixed to a knuckle arm 107 extending from the wheel support 103. Therefore, when the steering force is input to the power steering unit 2 through the steering shaft (not shown) by the steering of the steering wheel (not shown) by the driver, the steering force is assisted by the motor (not shown) in the power steering unit 2. Then, the tie rod 21 is displaced left and right in accordance with the steering direction, whereby the wheel is steered. Since the configuration and operation of the ball screw type power steering unit 2 are well known, description thereof will be omitted.
[0022]
The reinforcing plate 3 is fastened together with the power steering unit 2 from the front of the power steering unit 2 to the mounting seat 110 of the front frame 11 by bolts 4. The reinforcing plate 3 has a shape that covers the four mounting seats 110, and a bolt hole 30 through which the bolt 4 can pass is provided at a location corresponding to the mounting seat 110. That is, four bolt holes 30 are integrally formed in the reinforcing plate 3 so as not to be in a straight line corresponding to the mounting seat 110 provided in the suspension cross member 1. Further, the reinforcing plate 3 is bent along its longitudinal direction (direction substantially coincident with the longitudinal direction of the power steering unit 2 when attached to the vehicle), and the cross section in the direction perpendicular to the longitudinal direction is substantially uniform. It is Ω-shaped. In other words, it has a main body 31 composed of a curved portion 310 whose cross section is formed in an arc shape and flange portions 311 on both sides thereof. The bolt hole 30 is formed in the flange portion 311. Furthermore, the extension part 32 which protrudes right and left is provided in the longitudinal direction both ends of the reinforcement plate 3. As shown in FIG. The extension part 32 is formed separately from the main body part 31, and two bolt holes (not shown) corresponding to the bolt holes 30 are formed on the main body part 31 side of the left and right extension parts 32, respectively. The fastening plate 110 and the power steering unit 2 are fastened together with the mounting seat 110 together. On the other hand, the end portion 320 of the extension portion 32 corresponding to the vehicle width direction is bolted to the lower surface of the front side frame of the vehicle V. The end 320 is preferably detachably fixed so that the entire suspension unit 1 can be easily removed from the vehicle V for maintenance inspection of the engine E or the like. The shape of the reinforcing plate 3 will be described in detail later.
[0023]
Therefore, the power steering unit 2 is fastened and fixed to the front frame 11 by the four bolts 4 from the outside (front) through the reinforcing plate 3. In fixing the power steering unit 2 and the reinforcing plate 3 to the front frame 11, first, the power steering unit 2 is positioned so that the tie rod 21 is positioned with respect to the knuckle arm 107 and the through hole 20 corresponds to the mounting seat 110 of the front frame 11. In the applied state, the body portion 31 of the reinforcing plate 3 is positioned from the outside (front) so that the bolt hole 30 corresponds to the through hole 20 of the power steering unit 2 and the bolt hole of the extension portion 32 is similarly formed in the through hole 20. In such a state, positioning is performed so that the main body 31, the extension 32, and the power steering unit 2 are fastened and fixed to the mounting seat 110 with the four bolts 4. When the suspension unit 10 to which the power steering unit 2 and the reinforcing plate 3 are attached is fixed to the vehicle V, or in the subsequent process, the end portion 320 of each extension portion 32 is bolted to the front side frame of the vehicle V. Then, the attachment of the reinforcing plate 3 is completed.
[0024]
The power steering unit 2 and the reinforcing plate 3 may be fixed to the front frame 11 after the suspension unit 10 is assembled to the vehicle V. That is, after the suspension unit 10 is fixed to the vehicle V, the power steering unit 2 and the main body portion 31 and the extension portion 32 of the reinforcing plate 3 are positioned and fixed together with the bolt 4 as described above, and then the end of the extension portion 32 is fixed. The part 320 may be fixed to the front side frame.
In a state where the fixing of the reinforcing plate 3 to the vehicle V is completed, the reinforcing plate 3 is fastened to the front frame 11 together with the power steering unit 2 at four locations, and therefore combined with the shape of the curved portion 310, It functions as a reinforcement against external force applied to the power steering unit 2 and the suspension cross member 1. That is, even if a lateral force is input from the front tire while the vehicle is running, the reinforcing plate 3 is fixed at three or more attachment points that are not arranged linearly, and in the longitudinal direction of the power steering unit 2. Since the power steering unit 2 and the front frame 11 are not deformed even if a twist or an external force in the bending direction is applied to the power steering unit 2, the power steering unit 2 is not deformed. The steering torque can be assisted smoothly and the target steering feeling can be secured. Further, since the reinforcing plate 3 is also fixed to the front side frame by the extension portion 32, the reinforcing plate 3 is more firmly fixed to the vehicle V, and the reinforcing plate 3 itself can be prevented from being deformed or displaced to the maximum. .
[0025]
Next, the shape of the reinforcing plate 3 will be described with reference to FIGS. 3 (a) to 3 (c). 3A is a front view of the reinforcing plate 3 viewed from the direction corresponding to the front in the vehicle mounting state, and FIG. 3B is a bottom view of the reinforcing plate 3 viewed from the lower side in the vehicle mounting state. (C) is the side view seen from the direction equivalent to the vehicle advancing direction left side similarly in a vehicle attachment state.
[0026]
As described above, the reinforcing plate 3 is bent along its longitudinal direction (a direction substantially coincident with the longitudinal direction of the power steering unit 2 when attached to the vehicle), and the cross section in the direction perpendicular to the longitudinal direction is one. It is almost like Ω shape. In other words, it has a main body 31 composed of a curved portion 310 whose cross section is formed in an arc shape and flange portions 311 on both sides thereof. The bolt hole 30 is formed in the flange portion 311. Further, a substantially triangular extension 32 is provided at a predetermined angle from both longitudinal ends of the reinforcing plate 3, and the power steering unit 2 and the main body 31 are connected to the main body 31 side of the left and right extension 32 by bolts 4. The end 320 is bolted to the lower surface of the front side frame of the vehicle V in a detachable manner.
[0027]
Specifically, the main body 31 is formed by press-forming a rectangular steel plate so that the cross section has a substantially Ω shape. Thereafter, bolt holes 30 are formed in the vicinity of both side ends of each flange portion 311.
[0028]
Further, the extension portion 32 protrudes left and right at a predetermined angle with respect to the main body portion 31 from both ends of the bending portion 310 of the main body portion 31 as described above. The extension part 32 has a substantially triangular shape with the edge on the main body part 31 side as a base, and a part corresponding to the apex of the triangle is an end part 320. The main body 31 side of the left and right extension portions 32 is bifurcated, and bolt holes (not shown) are formed corresponding to the bolt holes 30 provided in the flange 311 at each branch portion. The extension 32 is fastened together with the main body 31 and the power steering unit 2 to the mounting seat 110 of the suspension subframe 1 through the bolt holes.
[0029]
On the other hand, a bolt hole is formed in the end portion 320 of the extension portion 32, and is detachably fixed to the front side frame via a bolt (not shown). When the main body 31 of the reinforcing plate 3 is fixed to the suspension cross member 1 and the extension 32 is fixed to the front side frame of the vehicle V, the extension 32 is connected to the main body 31 of the reinforcing plate 3 and the front side frame. It will be stretched between.
[0030]
Although the present invention has been described with reference to the preferred embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. . For example, the main body 31 of the reinforcing plate 3 is not limited to having a substantially Ω-shaped cross section, but may have a substantially hat-shaped cross section. Further, the reinforcing plate 3 can perform a reinforcing function as long as the reinforcing plate 3 and the power steering unit 2 are attached to the suspension cross member 1 at least a plurality of locations. More preferably, if there are at least three mounting locations and they are not arranged in a straight line, the reinforcing plate 3 acts as a surface constituted by the mounting portion, so that the suspension cross member 1 and the power steering unit 2 can be made stronger. Can be reinforced. Or you may provide five or more places by the arrangement | positioning which is not on a straight line.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a vehicle to which a front suspension device according to the present invention is applied.
FIG. 2 is an exploded perspective view of a suspension device, a power steering unit, and a reinforcing plate as viewed from the front side.
3A is a front view of the reinforcing plate viewed from the direction corresponding to the front in the vehicle mounted state, FIG. 3B is a bottom view of the reinforcing plate viewed from the lower side in the vehicle mounted state, and FIG. FIG. 4 is a side view of the reinforcing plate viewed from the direction corresponding to the left side in the vehicle traveling direction in the vehicle mounting state.
[Explanation of symbols]
1 Suspension cross member 2 Electric power steering device (electric power steering unit, power steering unit)
3 Reinforcing plate 4 Bolt
20 Through hole (Mounting part)
30 Bolt hole (mounting part)
32 Extension
110 Mounting base
310 Curved part (bent part)
V Vehicle (Automobile)

Claims (3)

A front suspension device for an automobile including a suspension cross member to which a ball screw type electric power steering device is attached,
The suspension cross member is disposed below the engine and below the front side frame. The suspension cross member includes front and rear frames that extend in the vehicle width direction and are arranged in the vehicle front-rear direction. ,
Both ends of the front frame in the vehicle width direction are attached to the front side frames that extend upward in the vehicle front view and are arranged on the left and right sides of the vehicle with respect to the vehicle width direction intermediate portion, respectively.
A mounting seat for fixing the electric power steering device is provided in the vehicle width direction intermediate portion of the front frame of the suspension cross member,
The above electric power steering apparatus, a plurality of mounting portions which are bolted to the mounting seat of the front frame of the suspension cross member is provided,
A reinforcing plate integrally having a mounting portion corresponding to each of the mounting portions of the electric power steering device;
The reinforcing plate includes a main body with the electric power steering device via the mounting portion of the reinforcing plate Ru are fastened together by bolts to the mounting seat of the front frame, respectively the vehicle width direction outer side from both ends of the body portion And has an extension fixed to the left and right front side frames of the vehicle,
A front suspension device for an automobile, wherein the main body portion and the extension portion of the reinforcing plate have a shape corresponding to the front frame when viewed from the front of the vehicle .   The electric power steering apparatus is provided with at least three attachment portions that are not arranged linearly, and the reinforcing plate is provided with at least three attachment portions corresponding to the attachment portions of the electric power steering. The front suspension apparatus for an automobile according to claim 1, wherein the front suspension apparatus is an automobile.   The said reinforcing plate has a bending part along the longitudinal direction of the said electric power steering apparatus in the state fastened together with the said suspension cross member with the said electric power steering apparatus, The said 1 or characterized by the above-mentioned. 3. The front suspension device for an automobile according to any one of 2 above.

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