JP2000225964A - Front body structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front body structure of a vehicle capable of establishing a lightweight construction and high rigidity compatibly. SOLUTION: At the other ends of a left 1A and a right longitudinal frame 1B of a perimeter frame 1, a steering gear unit 2 having a high rigidity in structural terms is installed facing to the left and right of the vehicle body, and the oversurface or undersurface of the steering gear unit 2 is coupled fast to the other ends of the frames 1A and 1B, and thereby the gear unit 2 is allowed to function as a strength member of perimeter frame 1 effectively. As a result, the gear unit 2 ensures a high rigidity of the perimeter frame 1 and accomplishes its lightweight construction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front body structure of a vehicle having a perimeter frame.

[0002]

2. Description of the Related Art In recent years, a monocoque body structure has been frequently used as a vehicle body structure from the viewpoint of improving the rigidity of a vehicle body. In this case, a perimeter frame that is mounted on the vehicle body while supporting the engine is employed. In this case, it is customary to mount a steering gear unit on the perimeter frame in the vehicle width direction (for example, Japanese Utility Model Publication No. 61-61). No. 19936).

[0003]

By the way, the conventional perimeter frame as shown in the above-mentioned known example has a problem in securing its rigidity.
In general, the steering gear unit is formed so as to have a substantially rectangular frame-like planar shape, and a frame portion on one side of the perimeter frame is supported. In addition, conventionally, a pair of members formed by pressing a perimeter frame having a concave cross-section are abutted to each other and joined to obtain a frame having a closed cross-section. From the point of thick plate,
There is a problem that the weight of the perimeter frame increases.

On the other hand, as one means for solving such a problem, it is conceivable to integrally mold the perimeter frame by a hydroform molding method instead of press molding. According to the perimeter frame formed by this hydroform molding method, the plate thickness can be reduced because of good moldability, and as a result, there is an advantage that the perimeter frame can be reduced in weight, but on the other hand, In addition, since the rigidity is reduced, it is necessary to take measures such as enlarging the cross-sectional dimension in order to improve the rigidity, and the weight reduction due to the reduction in the thickness inherent in the hydroform molding method is reduced, which is not preferable. Therefore, there is a demand for the development of a technology that can maintain the rigidity of the perimeter frame formed by the hydroform molding method while maintaining the advantages thereof.

Accordingly, the present invention is based on the premise of a perimeter frame formed by a hydroform molding method, and has been made with the object of proposing a front body structure of a vehicle capable of achieving both light weight and high rigidity. is there.

[0006]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

In the first invention of the present application, a pair of left and right vertical frames extending in the front-rear direction of the vehicle body and a horizontal frame portion extending in the left-right direction of the vehicle body by connecting one end of the pair of vertical frames to each other are provided. A perimeter frame formed by hydroforming and fixed to a vehicle body side frame, and having a ball circulation type disposed near the perimeter frame with its axis oriented in the lateral direction of the vehicle body In the vehicle provided with the steering gear unit, both ends of the steering gear unit are connected to the steered wheels inside the outer cylindrical member forming the outer peripheral wall, and the steering gear unit is capable of linearly moving in the vehicle width direction. An output shaft, a ball screw portion fitted and arranged on the outer peripheral side of the output shaft, and an electric assist device for rotating and driving the ball screw portion. Together and a mechanism, respectively,
The steering gear unit is disposed in the left-right direction of the vehicle so as to straddle between the other end portions of the pair of left and right vertical frame portions of the perimeter frame, and the upper surface or the lower surface thereof is formed by the pair of left and right vertical frame portions. Are fixedly connected to the other end portions of the respective members.

According to a second aspect of the present invention, in the front body structure for a vehicle according to the first aspect, the steering gear unit is rotatable by a plurality of bearings inside the outer cylinder member. The outer cylindrical member is fixed to the perimeter frame in the vicinity of the bearing arrangement position.

In the third invention of the present application, the first or the second
In the front body structure of the vehicle according to the invention, the steering gear unit is configured to support an engine mount arranged in the front-rear direction of the engine.

[0010]

According to the present invention, the following effects can be obtained by adopting such a configuration.

[0011] According to the front vehicle body structure of the vehicle according to the first invention of the present application, a pair of left and right vertical frames extending in the vehicle front-rear direction and one end of the pair of vertical frames are connected to each other and extend in the vehicle left-right direction. At the other end of the pair of left and right vertical frame portions of the perimeter frame formed by the hydroform molding method so as to have a frame-shaped planar form with the horizontal frame portion, an output shaft capable of linearly moving in the vehicle width direction. A steering gear unit having a ball screw portion fitted and arranged on the outer peripheral side of the output shaft and an electric assist mechanism for rotating and driving the ball screw portion inside the outer cylinder member is disposed facing the left and right direction of the vehicle body. The upper or lower surface of the steering gear unit is connected and fixed to the other ends of the pair of left and right vertical frame portions.

Therefore, the output shaft of the steering gear unit has high rigidity, and the electric assist mechanism is provided on the outer peripheral side of the output shaft. Since the rigidity is high, the steering gear unit has a high rigidity in a state of being fixed to the perimeter frame. As a result, by attaching the steering gear unit across the other end of the pair of left and right vertical frame portions of the perimeter frame, the steering gear unit can effectively function as a strength member of the perimeter frame, Even if the plane configuration of the perimeter frame is substantially "U" -shaped and is formed of a thin plate by the hydroform molding method, the perimeter frame and the steering gear unit have a substantially "B" -shaped plane configuration and are rigid. Frame can be obtained, and the perimeter frame is formed by the hydroform molding method, whereby the weight can be reduced, the cost can be reduced, and the engine support performance of the perimeter frame can be improved. .

Further, when the steering gear unit is fixed to the perimeter frame side, a supporting point on the steering gear unit side is set on an upper surface or a lower surface of the steering gear unit, and the two supporting points are set on the steering gear unit. By making the phase in the circumferential direction the same with respect to the axis of the shaft, even if the perimeter frame is torsionally deformed, the torsional force acts only on the steering gear unit as the bending force, and the torsion is applied. It does not act as force. In addition, when a bending force acts on the ball screw portion from the outer cylinder member, the output shaft receives the bending force, and thus has a characteristic that the bending strength is stronger than the torsional strength. Further, since the ball screw portion has a configuration in which the ball is arranged on the outer periphery of the output shaft, the ball screw portion can tolerate displacement in the bending direction. As a result, deformation of the steering gear unit is prevented as much as possible, and good steering performance is maintained for a long period of time.

According to the front body structure of the vehicle according to the second invention of the present application, the steering gear unit includes:
The output shaft is rotatably supported by a plurality of bearings inside the outer cylinder member, and the outer periphery of the outer cylinder member is fixed to the perimeter frame near the position where the bearing is arranged. Therefore, the load from the perimeter frame side can be efficiently supported by the highly rigid output shaft, and further improvement in the rigidity of the perimeter frame can be expected.

[0015] According to the front body structure of the vehicle according to the third invention of the present application, the steering gear unit includes:
Since the engine mount is supported in the front-rear direction of the engine, the steering gear unit has a higher rigidity than a frame material formed by press molding as in the prior art. Transmission or resonance thereof can be more effectively suppressed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A front body structure of a vehicle according to the present invention will be specifically described below based on a preferred embodiment.

FIG. 1 shows a perimeter frame 1 which is attached to a front portion of a vehicle body from below and functions as a support member of an engine unit E. The perimeter frame 1 is integrally formed by a hydroform molding method in which a tube is used as a raw material and is formed by applying an oil pressure thereto, and a pair of left and right vertical frame portions 1A, 1B is formed.
And one end 1Aa, 1 of the pair of vertical frame portions 1A, 1B.
By the horizontal frame portion 1C that makes Ba continuous, substantially “
It has a letter-shaped planar form.

The perimeter frame 1 is attached to a front portion of a vehicle body side frame (not shown) from below at the time of assembling the vehicle body. For this purpose, the other ends 1Ab, 1Bb of the vertical frame portions 1A, 1B are provided. And a vehicle body mounting mount 3 serving as a mounting portion to the vehicle body side frame at a position near both left and right ends of the horizontal frame portion 1C.
5, 35, ... are attached.

Since the perimeter frame 1 serves as a support member for the engine unit E, the bracket 36 for supporting the engine mount 37 is provided.
Are provided in the vertical frame portions 1A and 1B, the horizontal frame portion 1C, and the steering gear unit 2 described below.

By the way, this perimeter frame 1
From the viewpoint of reducing the weight, the shape itself is not changed to a generally general “b” shape, but is changed to a substantially “U” shape.
The thickness of the material is made thinner by applying a hydroform molding method than in the case of, for example, a press molding method. Therefore, the perimeter frame 1 has the advantage of being lightweight, but has insufficient rigidity in terms of the support performance of the engine unit E.

Therefore, in this embodiment,
Focusing on the fact that the steering gear unit 2 described below has a structure with high rigidity,
By using the rigidity of the perimeter frame 1
To improve rigidity.

The steering gear unit 2 is a ball-circulation type steering gear unit. As shown in FIG. 2, the inside of a large-diameter outer cylinder member 28 and a small-diameter outer cylinder member 29 that are concentrically connected to each other. The output shaft 21 is disposed at the center. The output shaft 21 is rotatably supported by bearings 25, 26, and 27 at a plurality of locations in the axial direction, and is movable in the axial direction. Also,
The output shaft 21 has a spiral groove formed on the outer peripheral surface thereof, and a ball nut 19 is fitted outside the spiral groove to form a ball screw portion 22. Further, at one axial end of the ball screw portion 22,
An electric assist mechanism 23 having a motor unit 24 is mounted so as to be located on the outer peripheral side of the output shaft 21, and the ball screw unit 22 is rotationally driven by the motor unit 24 so that the ball screw unit 22 The meshing output shaft 21 is appropriately moved in the axial direction, and steers steering wheels (not shown) connected to both ends. Further, a ball joint portion 20 serving as a connection portion to a steering shaft (not shown) is provided at a position near an end of the outer cylinder member 29 of the steering gear unit 2.

In the steering gear unit 2 having such a configuration, the output shaft 21 has a structure inherently having high rigidity due to a functional requirement.
Since the electric assist mechanism 23 having the motor unit 24 is mounted on the outer peripheral side of the output shaft 21, the outer cylindrical member 28 corresponding to the electric assist mechanism 23
The steering gear unit 2 has high rigidity as a whole because its diameter is large and its rigidity is high. Therefore, in order to improve the rigidity of the perimeter frame 1 by utilizing the rigidity of the steering gear unit 2, the steering gear unit 2 is connected and fixed to the perimeter frame 1.

Specifically, both ends of the perimeter frame 1, that is, the outer portions corresponding to the vicinity of the arrangement position of the bearing 25 for supporting the output shaft 21 to the outer cylindrical member 28 via the ball nut 19 are provided. A bearing 2 that supports the output shaft 21 on the outer peripheral surface of the cylindrical member 28 and the outer cylindrical member 29 side
Brackets 31 and 32 are protrudingly provided on the outer peripheral surface of the outer cylindrical member 29 corresponding to the vicinity of the arrangement position of the bracket 7.
In this case, the mounting position of the pair of brackets 31 and 32 is set at the same phase position in the circumferential direction with respect to the axis of the steering gear unit 2. Also,
An engine mount 37 is provided on the outer peripheral surface of the outer cylinder member 29.
Is provided.

On the other hand, corresponding to the brackets 31 and 32 on the steering gear unit 2 side, the brackets 3 are respectively located at positions near the other ends 1Ab and 1Bb of the pair of left and right vertical frame portions 1A and 1B of the perimeter frame 1.
0, 30 are formed.

The steering gear unit 2
The other end 1A of the pair of left and right vertical frame portions 1A, 1B
b, 1Bb. The brackets 31, 32 on the steering gear unit 2 side are arranged in this state so as to be straddled between the positions closer to 1Bb. And the perimeter frame 1 and the steering gear unit 2 constitute a frame structure having a substantially "B" -shaped plane configuration.

As described above, when the steering gear unit 2 is connected and fixed to the perimeter frame 1 to form a substantially "B" -shaped frame structure, the output shaft 21 of the steering gear unit 2 has high rigidity,
By providing the electric assist mechanism 23 on the outer peripheral side of the output shaft 21, the diameter of the outer cylinder member 28 is increased in the electric assist mechanism 23 and the rigidity thereof is increased. Has high rigidity in the state of being fixed to the perimeter frame 1. Therefore, the steering gear unit 2 is attached to the perimeter frame 1 by straddling the positions of the pair of left and right vertical frame portions 1A, 1B near the other end portions 1Ab, 1Bb. The perimeter frame 1 has a high rigidity as a whole, despite the fact that it functions effectively as a strength member, and the perimeter frame 1 has a substantially U-shaped plane configuration and is formed from a thin plate by a hydroform molding method. As a result, the perimeter frame 1 is formed by the hydroform molding method, whereby the weight is reduced and the cost is reduced, and the perimeter frame 2 improves the engine support performance.

Further, the steering gear unit 2
When fixing the brackets 3 to the perimeter frame 1 side, the support points on the steering gear unit 2 side, that is, the mounting positions of the brackets 31 and 32 are both set on the lower surface of the steering gear unit 2 and these brackets 3
Even if the perimeter frame 1 is twisted and deformed by making the phases of the peripheral gears 1 and 32 coincide with the axis of the steering gear unit 2 in the circumferential direction, the torsional force is applied to the steering gear unit 2. It acts only as a bending force and not as a twisting force. As a result, although the steering gear unit 2 has a characteristic that the torsional strength is weaker than the bending strength due to its structure, deformation of the steering gear unit 2 is prevented as much as possible, and Therefore, good steering performance is maintained for a long time.

The steering gear unit 2
The output shaft 21 is rotatably supported by a plurality of bearings 25 to 27 inside the outer cylinder members 28 and 29, and the outer cylinder member 28 is disposed near the position where the bearings 25 to 27 are arranged. , 29 are fixed to the perimeter frame 1, the perimeter frame 1 is fixed by the output shaft 21 having high rigidity.
The load from the side can be efficiently supported, and further improvement in the rigidity of the perimeter frame 1 can be expected.

Further, the steering gear unit 2
The steering gear unit 2 supports the engine mount 37 disposed on the front side of the engine E by using the steering gear unit 2. Since the rigidity is relatively high, the transmission of the vibration of the engine E to the vehicle body or the resonance thereof can be more effectively suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a front vehicle body structure according to the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

[Explanation of symbols]

1 is a perimeter frame, 2 is a steering gear unit, 20 is a ball joint unit, 21 is an output shaft, 22 is a ball screw unit, 23 is an electric assist mechanism, 24 is a motor unit, 25 to 27 are bearings, and 30 to 32 are brackets. , 33 and 34 are mounting bolts, 35 is a vehicle body mounting mount, 36 is a bracket, 37 is an engine mount, and E is an engine.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B62D 25/20 B62D 25/20 C F-term (Reference) 3D003 AA01 AA04 AA06 BB01 CA09 DA03 DA09 3D033 CA02 CA04 3D035 CA13 CA14 CA27

Claims (3)

[Claims] 1. A hydroform molding process comprising a pair of left and right vertical frames extending in the vehicle longitudinal direction and a horizontal frame extending in the vehicle left and right direction with one end of the pair of vertical frames connected to each other. A perimeter frame formed by a method and supporting the engine in a state fixed to the vehicle body side frame, and a ball circulation type steering gear unit arranged near the perimeter frame with its axis oriented in the left and right direction of the vehicle body. In the vehicle provided with the steering gear unit, an output shaft having both ends connected to steerable wheels and capable of linearly moving in the vehicle width direction inside an outer cylindrical member forming an outer peripheral wall of the steering gear unit; A ball screw part fitted and arranged on the outer peripheral side of the shaft and an electric assist mechanism for rotating and driving the ball screw part are provided. In addition, the steering gear unit is arranged in the left-right direction of the vehicle body so as to straddle between the other end portions of the pair of left and right vertical frame portions of the perimeter frame, and the upper surface or the lower surface of the pair of left and right A front body structure of a vehicle, wherein the vehicle body structure is connected and fixed to the other end of the vertical frame portion. 2. The steering gear unit according to claim 1, wherein the output shaft is rotatably supported by a plurality of bearings inside the outer cylinder member, and the output shaft is provided near a position where the bearings are arranged. A front body structure of a vehicle, wherein an outer peripheral side of the outer cylinder member is fixed to the perimeter frame. 3. The front body structure of a vehicle according to claim 1, wherein the steering gear unit is configured to support an engine mount arranged in a front-rear direction of the engine.