JP2018083437A - Vehicle front structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress bump steer in a vehicle in which a lower arm and tie rod are connected to a knuckle supporting a steering wheel.SOLUTION: In a vehicle front structure which includes a steering shaft 17, a translation member 21, a knuckle 56, a lower arm 58, a tie rod 36 and a rear extension member 90, and in which engagement means 25 and the rear extension member 90 are arranged on the same side sandwiching the vehicle center in the vehicle body width direction at the vehicle body cross direction position where the engagement part between the lower end part of the steering shaft 17 and the translation member 21 is located, the lower arm 58 and the tie rod 36 are arranged substantially in parallel when viewed from the vehicle body cross direction, and a region P1 of occupation of the engagement means 25 in the vehicle body width direction overlaps a region P10 of the rear extension member 90 in the vehicle body width direction at the vehicle body cross direction position where the engagement part between the lower end part of the steering shaft 17 and the translation member 21 is located.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle front structure in which a lower arm and a tie rod are connected to a knuckle that supports a wheel.

  In general, an automobile steering mechanism includes a steering shaft that transmits rotation of a steering wheel, a steering gear box that is engaged with a lower end portion of the steering shaft, and converts the rotational movement of the steering shaft into a translational movement along the vehicle body width direction. It has. A translation member such as a rack shaft provided in the steering gear box is connected to a knuckle that supports the steered wheels at each end in the vehicle body width direction via a tie rod extending in the vehicle body width direction.

  The tie rod is connected to the knuckle through a ball joint or the like at the outer end in the vehicle width direction. When the steering operation is performed, the tie rod moves in the vehicle body width direction together with the translation member of the steering gear box, and thereby the connection portion of the knuckle with the tie rod is moved to the right side or the left side in the vehicle body width direction. The wheel is steered.

  The knuckle that supports the steered wheels may be further coupled with a lower arm that constitutes a suspension mechanism. The lower arm is usually connected to a subframe (suspension member) via a shaft member and a rubber bush at two locations inside the vehicle width direction, respectively, and a knuckle via a ball joint or the like at one location outside the vehicle width direction. Connected to

  For example, as disclosed in Patent Document 1 (particularly, refer to FIG. 5 of the same document), when a lower arm and a tie rod are connected to a steering wheel knuckle, the lower arm and the tie rod are viewed from the vehicle longitudinal direction. They may be arranged substantially parallel to each other.

JP 2006-306247 A

  When the lower arm and the tie rod are disposed substantially parallel to each other when viewed from the front-rear direction of the vehicle body, when the steered wheel strokes (bumps or rebounds) in the vertical direction of the vehicle body, the lower arm 101 and the tie rod 201 are The behavior as shown in the schematic diagrams of a) to FIG.

  6A shows an example in which the vehicle body width direction length L1 of the lower arm 101 is larger than the vehicle body width direction length L2 of the tie rod 201 when viewed from the front side of the vehicle body, and FIG. 6B shows the lower arm 101 and the tie rod 201. In the example in which the vehicle body width direction lengths L1 and L3 are equal, FIG. 6C shows that the vehicle body width direction lengths L4 and L5 of the lower arm 101 and the tie rod 201 are larger than the lengths L1 and L2 of FIG. In addition, examples in which the length L4 of the lower arm 101 is larger than the length L5 of the tie rod 201 are shown.

  6 (a) to 6 (c), the connecting portion 103 of the lower arm 101 to the knuckle and the connecting portion 203 of the tie rod 201 to the knuckle are connected to the vehicle body according to the bump or rebound of the steering wheel. When the lower arm 101 and the tie rod 201 swing around the connecting portions 102 and 202 on the inner side in the vehicle width direction, the connecting portions 103 and 203 for the knuckle are always the same in the vehicle width direction. Can be displaced sideways.

  However, as shown in FIG. 6A, when the length L1 of the lower arm 101 and the length L2 of the tie rod 201 in the vehicle body width direction are different, both connecting portions 103 and 203 with respect to the knuckle have the same height in the vehicle body vertical direction. When the stroke is H1, the swinging angles R1 and R2 of the lower arm 101 and the tie rod 201 are different, so that the displacement amounts D1 and D2 of the connecting portions 103 and 203 in the vehicle body width direction are different.

  For example, as shown in FIG. 6A, when the length L2 of the tie rod 201 is shorter than the length L1 of the lower arm 101, the swing angle R2 of the tie rod 201 compared to the swing angle R1 of the lower arm 101. Is increased, the displacement amount D2 of the connecting portion 203 of the tie rod 201 is larger than the displacement amount D1 of the connecting portion 103 of the lower arm 101 with respect to the knuckle.

  As a result, a difference occurs between the displacement amounts D1 and D2 of both the connecting portions 103 and 203, thereby changing the toe angle of the steered wheels. That is, so-called bump steer in which the toe angle changes according to the vehicle body vertical stroke of the steered wheels occurs.

  Therefore, as shown in FIG. 6 (b), if the length L1 of the lower arm 101 and the length L3 of the tie rod 201 are made equal, both swing angles R1 of the lower arm 101 and the tie rod 201 become equal, so The displacements D1 and D3 in the vehicle body width direction of the connecting portions 103 and 203 can be made equal, thereby suppressing bump steer.

  Further, even when the lengths of the lower arm 101 and the tie rod 201 cannot be made completely equal, as shown in FIG. 6C, if the vehicle body width direction lengths L4 and L5 of the lower arm 101 and the tie rod 201 are as large as possible, The swinging angles R4 and R5 of the lower arm 101 and the tie rod 201 at the time of bumping or rebounding can be reduced, and thereby the displacement amounts D4 and D5 of the connecting portions 103 and 203 with respect to the knuckle can be reduced. Therefore, the difference between the displacement amounts D4 and D5 of both the connecting portions 103 and 203 can be reduced, thereby suppressing bump steer.

  In other words, in order to effectively suppress the bump steer, it is effective to make the lengths of the lower arm 101 and the tie rod 201 in the vehicle width direction as large as possible and as equal as possible. For this purpose, the swinging of the lower arm 101 and the tie rod 201 is effective. It is preferable to arrange the connecting portions 102 and 202 on the inner side in the vehicle width direction as shafts as close as possible to the inner side in the vehicle width direction.

  However, there is an engaging means (for example, a pinion gear meshing with the rack shaft) that engages the lower end portion of the steering shaft with the translation member on the inner side in the vehicle width direction of the connecting portion between the tie rod and the translation member such as the rack shaft. Further, an exhaust pipe of an engine, a propeller shaft, and the like may be disposed further inside the engagement means in the vehicle width direction.

  In such a case, it is difficult to arrange the connecting portion between the tie rod and the translation member inward in the vehicle body width direction, so it is difficult to secure a large tie rod size in accordance with the size of the lower arm in the vehicle body width direction. It becomes. For this reason, when the steering wheel bumps or rebounds, the difference in the amount of displacement in the vehicle body width direction between the connecting portions of the lower arm and the tie rod with respect to the knuckle tends to increase, and it becomes difficult to suppress the bump steer.

  Therefore, an object of the present invention is to effectively suppress bump steer in a vehicle in which a lower arm and a tie rod are connected to a knuckle that supports a steered wheel.

  In order to solve the above-described problems, the vehicle front structure according to the present invention is configured as follows.

First, the invention according to claim 1 of the present application is
A steering shaft extending in a direction inclined toward the vehicle body lower side toward the vehicle body front side, and is engaged with a lower end portion of the steering shaft via predetermined engagement means to rotate around the axis of the steering shaft. A translation member that translates along the vehicle body width direction in conjunction with the vehicle body, a knuckle that supports a steering wheel, a lower arm that couples the knuckle to a subframe, a tie rod that couples the knuckle to the translation member, and the translation member A rear extension member extending from the front side portion of the vehicle body to the rear side of the vehicle body, and sandwiching the vehicle center in the vehicle body width direction at the vehicle longitudinal direction position where the engaging portion between the lower end portion of the steering shaft and the translation member is located It is a vehicle front structure in which the engagement means and the rear extension member are arranged on the same side,
The lower arm and the tie rod are disposed substantially in parallel when viewed from the front-rear direction of the vehicle body,
The region occupied by the engaging means in the vehicle body width direction overlaps the region occupied by the rearward extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engaging portion between the lower end portion of the steering shaft and the translation member is located. It is characterized by.

  Specific examples of the “engagement means” here include a pinion gear that meshes with the rack shaft of the steering gear box. Further, specific examples of the “rear extension member” herein include an engine exhaust pipe or a propeller shaft that transmits power from the engine side to the rear wheel side.

According to a second aspect of the present invention, there is provided a vehicle front structure according to the first aspect of the present invention.
The region occupied by the engagement portion between the lower end portion of the steering shaft and the translation member in the vehicle body width direction overlaps the region occupied by the rear extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engagement portion is located. It is characterized by.

According to a third aspect of the present invention, there is provided the vehicle front portion structure according to the first or second aspect of the invention.
The rear extension member is an exhaust pipe of an engine;
An insulator is interposed between the cover member that covers the steering shaft and the exhaust pipe.

According to a fourth aspect of the present invention, there is provided the vehicle front structure according to the third aspect of the present invention.
The insulator is attached to a case that houses the translation member.

According to a fifth aspect of the present invention, there is provided the vehicle front structure according to the third or fourth aspect of the invention.
The cover member is a cylindrical member that covers the steering shaft,
The insulator includes a side covering portion that covers the cover member from the vehicle width direction inner side and a front covering portion that covers the cover member from the vehicle body front side.

  According to the first aspect of the present invention, on one side of the vehicle center in the vehicle body width direction, the region in which the engagement means for engaging the lower end portion of the steering shaft with the translation member of the steering mechanism occupies the vehicle body width direction is Since the rear extension member overlaps the region occupied in the vehicle body width direction at the vehicle body front-rear direction position where the engagement portion between the lower end portion of the steering shaft and the translation member is located, the engagement means is moved inward in the vehicle body width direction. Easier to place. Therefore, it becomes easy to arrange the connecting portion between the translation member and the tie rod so as to be closer to the inner side in the vehicle body width direction in accordance with the engaging means. This makes it easy to ensure a large vehicle body width direction length of the tie rod in accordance with the vehicle body width direction length of the lower arm that is not subject to the arrangement restriction by the engaging means.

  Accordingly, the lower arm and the tie rod arranged substantially in parallel when viewed from the front-rear direction of the vehicle body have a large and equivalent length in the vehicle width direction, so that when the steering wheel strokes in the vertical direction of the vehicle body, It is possible to reduce the difference in displacement in the vehicle body width direction between the connecting portions of the lower arm and the tie rod with respect to the knuckle that supports the bumps, thereby effectively suppressing the bump steer.

  According to the second aspect of the present invention, the region where the engagement portion between the lower end portion of the steering shaft and the translation member occupies the vehicle body width direction is the vehicle body longitudinal direction position where the engagement portion is located. Since it overlaps with the area which occupies in the width direction, it becomes easier to place the connecting portion between the translation member and the tie rod closer to the inner side in the vehicle body width direction, so the above-described suppression of bump steer is more effective. Can be realized.

  According to the third aspect of the present invention, the lower end side portion of the steering shaft is disposed close to the exhaust pipe of the engine, and the exhaust pipe is provided by the insulator interposed between the cover member that covers the steering shaft and the exhaust pipe. Since the heat is blocked, the cover member can be protected from heat damage.

  If the invention according to claim 4 is applied to the invention according to claim 3, since the insulator is attached to the case that accommodates the translation member, the cover member omits the protruding portion such as the boss for attaching the insulator. be able to. Therefore, it becomes easy to arrange the insulator close to the cover member, and this facilitates the arrangement in which the exhaust pipe and the engaging means are overlapped in the vehicle body width direction as described above.

  When the invention according to claim 5 is applied to the invention according to claim 3 or claim 4, the cylindrical cover member is covered with the insulator from the vehicle body width direction inner side and the vehicle body front side, so that the cover member Can be more effectively suppressed.

It is the front view which looked at the vehicle front part structure concerning the embodiment of the present invention from the body front side. It is the top view which looked at a part of the structure from the vehicle body upper side. It is sectional drawing which looked at the internal structure of the engagement unit and its peripheral part from the vehicle body width direction. FIG. 2 is a partially enlarged view of FIG. 1 in which the engaging unit and its peripheral part are viewed from the front side of the vehicle body. It is the side view which looked at the engagement unit and its peripheral part from the body width direction. It is a figure for demonstrating the relationship between the vehicle body width direction length of a lower arm and a tie rod, and bump steer.

  Hereinafter, a vehicle front structure according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, terms indicating directions such as “front”, “rear”, “right”, “left”, “up”, “down”, and the like are used unless otherwise specified. Each direction of the vehicle body when the traveling direction during forward traveling is set to “front” shall be indicated.

  FIG. 1 is a front view of the vehicle front structure according to the present embodiment as viewed from the front side of the vehicle body, and FIG. 2 is a plan view of a part of the right side portion of the vehicle as viewed from above the vehicle body. .

  As shown in FIGS. 1 and 2, the dash panel 2 that partitions the vehicle interior space and the engine room in the longitudinal direction of the vehicle body includes a dash panel lower 3 and a dash panel upper joined to the upper end of the dash panel lower 3. (Not shown) and a toe board 4 joined to the lower end of the dash panel lower 3.

  A tunnel portion 3a is provided at the center of the lower end portion of the dash panel lower 3 in the vehicle body width direction, and an engine exhaust pipe 90 extending in the longitudinal direction of the vehicle body is passed through the tunnel portion 3a. The exhaust pipe 90 is disposed offset to the right side of the center of the vehicle in the vehicle body width direction.

  The toe boards 4 are arranged on both the left and right sides of the tunnel portion 3a in the vehicle body width direction. The toe board 4 is disposed so as to be inclined toward the vehicle body upper side toward the vehicle body front side. A side frame 6 extending in the longitudinal direction of the vehicle body is joined to the lower surface (front surface) of the toe board 4. A pair of side frames 6 are provided on the left and right sides with a gap in the vehicle body width direction.

  A suspension mechanism 50 is provided on the vehicle body front side of the dash panel 2. In the present embodiment, the suspension mechanism 50 is a so-called strut type front suspension.

  The suspension mechanism 50 includes a subframe (suspension member) 8 coupled to the vehicle body, a pair of left and right knuckles 56 that rotatably support a hub 52 of a wheel (steering wheel) via a bearing 54, and each knuckle 56 is supported by the subframe 8. And a pair of left and right struts 69 provided between each knuckle 56 and a wheel house (not shown) of the vehicle body.

  The sub frame 8 is supported by the vehicle body by being connected to the side frame 6. A power train (not shown) including an engine is supported on the subframe 8.

  As shown in FIG. 2, each lower arm 58 is provided so as to extend in the longitudinal direction of the vehicle body at an inner portion in the vehicle body width direction and to extend while curving from the front end portion toward the outer side in the vehicle body width direction.

  The lower arm 58 is connected to the subframe 8 via a pair of front and rear connecting portions 60 at the inner side in the vehicle width direction. Although the illustration of the connecting portion on the rear side is omitted, the connecting portion is connected so as to be rotatable around an axis extending in the vertical direction of the vehicle body. The front connection portion 60 connects the lower arm 58 to the sub-frame 8 so as to be rotatable around an axis extending in the longitudinal direction of the vehicle body.

  The outer end of the lower arm 58 in the vehicle width direction is connected to the knuckle 56 via a connecting portion 62 made of, for example, a ball joint. Thus, the knuckle 56 is connected to the subframe 8 via the lower arm 58.

  As shown in FIG. 1, each strut 69 is provided as a main component such that a coil spring 80 interposed between the wheel and the vehicle body to absorb shocks and extendable and contractable between the wheel and the vehicle body. And a damper 70 for absorbing the vibration of the coil spring 80.

  The damper 70 is, for example, a telescopic type provided with a cylinder and a piston rod. The axis of the damper 70 is disposed so as to be inclined inward in the vehicle body width direction toward the vehicle body upper side with respect to the vehicle body vertical direction. The lower end portion of the damper 70 is fixed to the knuckle 56.

  An upper mount 72 is attached to the upper end portion of the damper 70. The upper mount 72 is fixed to, for example, a wheel house (not shown) of the vehicle body by bolts, for example. Accordingly, the upper end portion of the damper 70 is connected to the vehicle body via the upper mount 72.

  An upper spring seat 74 is provided on the lower side of the vehicle body of the upper mount 72. The upper spring seat 74 is attached to the upper end portion of the damper 70 via the upper mount 72.

  A lower spring seat 76 is attached to an intermediate portion in the length direction of the damper 70. The lower spring seat 76 is fixed to the outer peripheral surface of the damper 70 by welding, for example.

  The coil spring 80 is interposed between the upper spring seat 74 and the lower spring seat 76. Seat rubbers (not shown) are interposed between the coil spring 80, the upper spring seat 74, and the lower spring seat 76, respectively, thereby reducing the impact and reducing noise. The coil spring 80 is provided so as to surround the damper 70.

  As shown in FIGS. 1 and 2, a tie rod 36 arranged to extend in the vehicle body width direction is connected to a knuckle 56 that supports a wheel (steering wheel) via a connecting portion 64 made of, for example, a ball joint. Has been.

  The connecting portion 64 of the tie rod 36 with respect to the knuckle 56 is disposed behind the connecting portion 62 of the lower arm 58 with respect to the knuckle 56, on the rear side in the vehicle longitudinal direction, on the upper side in the vehicle vertical direction, and on the inner side in the vehicle width direction in the steering neutral state. .

  As shown in FIG. 1, the tie rod 36 is disposed substantially parallel to the lower arm 58 when viewed from the front-rear direction of the vehicle body. The end of the tie rod 36 on the inner side in the vehicle body width direction is connected to a steering mechanism 10 described below. Has been.

  As shown in FIG. 2, the steering mechanism 10 includes a steering wheel 12 disposed on the vehicle body front side of the driver's seat in the vehicle interior space, and a direction inclined toward the vehicle body lower side from the steering wheel 12 toward the vehicle body front side. A steering shaft 14 arranged to extend, and a steering gear box 20 engaged with a lower end portion of the steering shaft 14 are provided.

  The vehicle in the present embodiment is a so-called right-hand drive vehicle in which the driver's seat is provided on the right side of the vehicle body, and the steering wheel 12 and the steering shaft 14 are disposed on the right side of the vehicle center in the vehicle body width direction.

  The steering shaft 14 includes a plurality of shaft members 15, 16, and 17 that are connected to each other via universal joints 18 and 19. More specifically, the steering shaft 14 in the present embodiment is configured by connecting an upper shaft member 15, an intermediate shaft member 16, and a lower shaft member 17 in this order from the vehicle body upper side. When the steering wheel 12 is rotated, this rotational motion is transmitted to the lower shaft member 17 via the upper shaft member 15 and the intermediate shaft member 16.

  The upper shaft member 15 and the intermediate shaft member 16 are disposed on the rear side of the vehicle body from the dash panel 2, and the lower shaft member 17 is disposed through the toe board 4 of the dash panel 2. The lower shaft member 17 is disposed to be inclined toward the vehicle body front side and the vehicle body lower side and the vehicle body width direction. An engagement unit 24 that engages the steering shaft 14 with the steering gear box 20 is provided at the lower end of the lower shaft member 17.

  As shown in FIG. 3, the engagement unit 24 includes a pinion gear 25 as an engagement means provided at the lower end portion of the lower shaft member 17, and a pinion case 26 that houses the pinion gear 25.

  The pinion gear 25 is formed on the outer peripheral surface of the lower end portion of the lower shaft member 17. The pinion case 26 is made of, for example, metal. The pinion case 26 is provided integrally with a rack case 22 described later, and is supported by the subframe 8 (see FIGS. 1 and 4) via the rack case 22.

  The pinion case 26 is integrally connected to the cylindrical first case portion 26a surrounding the outer peripheral surface of the pinion gear 25 and the upper end side of the first case portion 26a, and has a cylindrical first diameter that is larger than the first case portion 26a. 2 case part 26b. The second case portion 26 b is fitted to the outside of the lower shaft member 17 via the bearing 28. Thus, the lower end portion of the steering shaft 14 is supported by the pinion case 26 via the bearing 28 so as to be rotatable.

  The lower shaft member 17 is covered with a cylindrical cover member 32 in a portion between the toe board 4 and the pinion case 26 of the dash panel 2. The cover member 32 is made of, for example, resin.

  An enlarged diameter portion 32 a is provided at the lower end portion of the cover member 32, and the enlarged diameter portion 32 a is fitted to the outside of the second case portion 26 b of the pinion case 26. An O-ring 30 is interposed between the enlarged diameter portion 32a and the pinion case 26.

  A plate-like portion 32 b that extends outward in the radial direction is provided at the upper end portion of the cover member 32. An annular seal member 34 that seals between the cover member 32 and the toe board 4 is attached to the plate-like portion 32b. The seal member 34 is made of rubber, for example.

  As shown in FIGS. 3 and 4, the steering gear box 20 includes a rack shaft 21 disposed so as to extend in the vehicle body width direction, and a cylindrical rack case 22 that accommodates the rack shaft 21. The rack case 22 is made of, for example, metal and is supported by the subframe 8.

  The rack shaft 21 is rotatably supported by the rack case 22 via a bearing (not shown). The teeth 21 a formed on the outer peripheral surface of the rack shaft 21 mesh with the pinion gear 25 described above. Thereby, when the steering shaft 14 is rotated in accordance with the operation of the steering wheel 12 (see FIG. 2), the rack shaft 21 translates in the axial direction while rotating around its axis. That is, in the meshing portion between the pinion gear 25 and the rack shaft 21, the rotational motion around the axis of the steering shaft 14 is converted into the translational motion of the rack shaft 21 along the vehicle body width direction.

  The rack shaft 21 is disposed so as to protrude outward from the end of the rack case 22 on both sides in the vehicle body width direction. Each end of the rack shaft 21 is connected to a tie rod 36 via a connecting portion 38 made of, for example, a ball joint. The connecting portion 38 is covered with, for example, a bellows-like joint cover 39. The joint cover 39 is attached to the rack case 22 at the inner end in the vehicle width direction, and is attached to the tie rod 36 at the outer end.

  The tie rod 36 translates in the vehicle body width direction together with the rack shaft 21 according to the steering operation. At this time, the connection part with the tie rod 36 in the knuckle 56 is moved right and left, and the wheel supported by the knuckle 56 is steered.

  As shown in FIG. 4, the exhaust pipe 90 of the engine is disposed on the right side of the vehicle center in the vehicle body width direction, like the lower shaft member 17, on the vehicle front side of the dash panel 2.

  The cross section of the exhaust pipe 90 shown in FIG. 4 is a cross section at a position in the longitudinal direction of the vehicle body where the meshing portion between the pinion gear 25 and the rack shaft 21 is located.

  The front end portion of the exhaust pipe 90 is connected to an engine (not shown) disposed on the front side of the vehicle body with respect to the steering gear box 20 and the engagement unit 24. The exhaust pipe 90 is connected to the vehicle body from the connection portion with the engine. It arrange | positions so that it may extend to back side. Further, the exhaust pipe 90 is disposed so as to pass through the dash panel 2 by passing through the tunnel portion 3a, and further to the vehicle body rear side through a floor tunnel (not shown).

  The lower shaft member 17 passes through the toe board 4 of the dash panel 2 at a position inside the connecting portion 38 between the rack shaft 21 and the tie rod 36 and outside the tunnel portion 3a in the vehicle body width direction. . The engine exhaust pipe 90 is disposed so as to pass through a position adjacent to the inner side in the vehicle body width direction of the penetrating portion of the lower shaft member 17 in the dash panel 2.

  The lower shaft member 17 is disposed to be inclined inward in the vehicle body width direction toward the vehicle body lower side. The pinion gear 25 provided at the lower end of the lower shaft member 17 is arranged so that the position in the vehicle width direction overlaps with the tunnel portion 3a. The exhaust pipe 90 of the engine is arranged so as to pass through a position adjacent to the upper side of the vehicle body of the pinion gear 25.

  That is, the region P1 that the pinion gear 25 occupies in the vehicle body width direction overlaps the region P10 that the exhaust pipe 90 occupies in the vehicle body width direction at the vehicle body front-rear direction position where the engagement portion between the pinion gear 25 and the rack shaft 21 is located. Further, a region P2 in which the meshing portion between the pinion gear 25 and the rack shaft 21 occupies in the vehicle body width direction also overlaps with a region P10 in which the exhaust pipe 90 occupies in the vehicle body width direction.

  Thus, according to the present embodiment, the pinion gear 25 and the meshing portion with the rack shaft 21 are arranged so that the vehicle body width direction regions P1 and P2 overlap the region P10 of the exhaust pipe 90. Accordingly, the pinion gear 25 or the engagement unit 24 can be easily arranged close to the inner side in the vehicle body width direction.

  For this reason, the connecting portion 38 between the rack shaft 21 and the tie rod 36 can be easily arranged close to the inner side in the vehicle body width direction in accordance with the engagement unit 24. Therefore, it is easy to ensure a large length of the tie rod 36.

  On the other hand, as shown in FIGS. 1 and 2, the connecting portion 62 with the knuckle 56 at the outer end in the vehicle width direction of the lower arm 58 is more outward in the vehicle width direction than the connecting portion 64 with the knuckle 56 of the tie rod 36. A member that is positioned and restricts the arrangement of the connecting portion 60 with the subframe 8 at the inner end in the vehicle width direction of the lower arm 58 does not exist on the inner side in the vehicle width direction. It is easy to secure a large length as in the conventional case.

  Therefore, according to the present embodiment, the lengths of the lower arm 58 and the tie rod 36 in the vehicle body width direction can be configured to be large and substantially the same. Therefore, when the wheel strokes in the vertical direction with respect to the vehicle body, and when both the connecting portions 62 and 64 of the lower arm 58 and the tie rod 36 with respect to the knuckle 56 that supports the wheel stroke in the vertical direction of the vehicle body, It is possible to reduce the difference in the displacement amount of the connecting portions 62 and 64 in the vehicle body width direction, thereby effectively suppressing the bump steer.

  As shown in FIGS. 4 and 5, the cover member 32 and the O-ring 30 (see FIG. 3) are disposed between the lower shaft member 17 and the engine exhaust pipe 90 arranged close to each other as described above. Insulator 44 is provided to suppress thermal damage (see reference).

  The insulator 44 is composed of a single plate material. The insulator 44 is made of a metal such as iron, for example. The insulator 44 includes a base portion 45 that is disposed opposite to the upper side of the vehicle body of the rack case 22 of the steering gear box 20, and a side cover portion that is disposed to face the inner side in the vehicle body width direction of the upper ends of the cover member 32 and the pinion case 26. 46, and a front covering portion 47 disposed to face the vehicle body front side of the upper end portions of the cover member 32 and the pinion case 26.

  The base portion 45, the side covering portion 46, and the front covering portion 47 of the insulator 44 are each constituted by a flat plate portion. A flange portion 48 that is inclined from the base portion 45, the side covering portion 46, and the front covering portion 47 to the back surface side (the surface facing the rack case 22 or the cover member 32) is provided on the peripheral portion of the insulator 44. . Thereby, the surface rigidity of the insulator 44 is increased, and the vibration of the insulator 44 is suppressed.

  The base portion 45 is provided at an end portion of the insulator 44 on the vehicle body lower side and an inner end portion in the vehicle body width direction. The base portion 45 is disposed at a distance from the outer peripheral surface of the rack case 22 along a surface perpendicular to the vertical direction of the vehicle body.

  The rack case 22 is integrally provided with, for example, a pair of boss portions 22a and 22b protruding from the outer peripheral surface to the vehicle body upper side. The pair of boss portions 22a and 22b are disposed so as to be spaced apart from each other in the vehicle body width direction and shifted in the vehicle body longitudinal direction. The base portion 45 of the insulator 44 is fixed to the rack case 22 by bolts 40 and 41 screwed into the boss portions 22a and 22b. Thereby, the insulator 44 is supported in a cantilevered manner by the rack case 22.

  The side covering portion 46 is disposed so as to oppose the portion of the outer peripheral surface of the cover member 32 facing the inner side in the vehicle width direction with a space between the portion. The side covering portion 46 is disposed so as to be inclined toward the vehicle body lower side toward the inner side in the vehicle body width direction when viewed from the vehicle body front side (see FIG. 4). A lower end portion of the side covering portion 46 is connected to an end portion of the base portion 45 on the outer side in the vehicle width direction via a curved portion.

  The front covering portion 47 is disposed to face the front surface of the cover member 32 along the portion facing the front side of the vehicle body with a space therebetween. The front covering portion 47 is disposed so as to be inclined toward the vehicle body lower side toward the vehicle body front side when viewed from the vehicle body width direction (see FIG. 5). An edge of the front covering portion 47 on the inner side in the vehicle width direction is connected to the side covering portion 46 via a curved portion.

  The distance between the outer peripheral surface of the cover member 32 and the side cover portion 46 and the distance between the outer peripheral surface of the cover member 32 and the front cover portion 47 are smaller than the distance between the outer peripheral surface of the rack case 22 and the base portion 45. .

  Since the insulator 44 is disposed as described above, the cover member 32 is substantially entirely covered with the side covering portion 46 from the inner side in the vehicle body width direction (see FIG. 5), and the exhaust pipe 90 side one side. The portion is covered with a front covering portion 47 from the front side of the vehicle body (see FIG. 4).

  Therefore, according to the present embodiment, the lower shaft member 17 is disposed between the cover member 32 that covers the lower shaft member 17 and the exhaust pipe 90 while the lower end side portion of the lower shaft member 17 is disposed close to the exhaust pipe 90 of the engine. Since the heat of the exhaust pipe 90 is blocked by the insulator 44, the cover member 32 and the O-ring 30 (see FIG. 3) can be protected from heat damage.

  Further, since the insulator 44 is attached to the rack case 22, it is not necessary to provide a protruding part such as a boss part for attaching the insulator 44 in the cover member 32. Therefore, it is possible to avoid changing the material of the cover member 32 to metal or complicating the shape of the cover member 32.

  Furthermore, since there is no protrusion on the outer peripheral surface of the cover member 32, the insulator 44 can be easily placed close to the cover member 32. Therefore, it is easy to place the lower end portion of the lower shaft member 17 and the cover member 32 close to the inner side in the vehicle body width direction while securing a necessary interval between the insulator 44 and the exhaust pipe 90, and as described above. Such an arrangement in which the exhaust pipe 90 and the pinion gear 25 are overlapped in the vehicle body width direction can be easily realized.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the example in which the rack and pinion mechanism is used for the engagement between the lower end portion of the steering shaft and the translation member of the steering gear box has been described. The mechanism is not particularly limited.

  In the above-described embodiment, the example in which the exhaust pipe of the engine is provided as the “rear extension member” in the claims is described. However, in the present invention, the rear extension member is not limited to this, for example, A propeller shaft that transmits power from the engine side to the rear wheel side may be used.

  Furthermore, in the above-described embodiment, an example in which a so-called strut-type suspension mechanism is provided has been described. However, in the present invention, if the lower arm and the tie rod are connected to the knuckle, a specific type of the suspension mechanism is It is not limited.

  Furthermore, in the above-described embodiment, the present invention has been described by taking a so-called right-hand drive vehicle in which the driver's seat and the steering mechanism are arranged on the right side of the vehicle body as an example, but the present invention can be similarly applied to the left handle. is there.

  As described above, according to the present invention, bump steer can be effectively suppressed in an automobile in which a lower arm and a tie rod are connected to a knuckle that supports a steered wheel. There is a possibility that it is preferably used.

2 Dash panel 8 Subframe 10 Steering mechanism 14 Steering shaft 20 Steering gear box 21 Rack shaft (translation member)
22 rack case 22a, 22b boss portion 24 engagement unit 25 pinion gear 26 pinion case 30 O-ring 32 cover member 36 tie rod 38 connecting portion 44 insulator 45 base portion 46 side covering portion 47 front covering portion 50 suspension mechanism 52 wheel hub 56 Knuckle 58 Lower arm 60 Connecting portion 62 Connecting portion 64 Connecting portion 69 Strut 70 Damper 80 Coil spring

First, the invention according to claim 1 of the present application is
A dash panel that partitions the space between the vehicle interior space and the engine room in the longitudinal direction of the vehicle body, and a steering shaft that extends through the dash panel in a direction inclined downward from the vehicle interior space toward the front side of the vehicle body A translation member that engages with a lower end portion of the steering shaft via predetermined engagement means and performs a translational motion along the vehicle body width direction in conjunction with a rotational motion around the axis of the steering shaft; A steering knuckle, a lower arm that couples the knuckle to a subframe, a tie rod that couples the knuckle to the translation member, and a rear extension member that extends from the front side portion of the vehicle body to the rear side of the vehicle body than the translation member. In the vehicle body longitudinal direction position where the engagement portion between the lower end of the shaft and the translation member is located, A vehicle front structure sandwiching the vehicle center the said engaging means on the same side rear extension member is disposed that,
The lower arm and the tie rod are disposed substantially in parallel when viewed from the front-rear direction of the vehicle body,
The region occupied by the engaging means in the vehicle body width direction overlaps the region occupied by the rearward extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engaging portion between the lower end portion of the steering shaft and the translation member is located. ,
The region occupied by the engagement portion between the lower end portion of the steering shaft and the translation member in the vehicle body width direction overlaps the region occupied by the rear extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engagement portion is located. ,
The tie rod is located on the rear side of the connecting portion between the knuckle and the lower arm ,
The dash panel includes a dash panel lower and a toe board joined to a lower end of the dash panel lower,
The dash panel lower has a tunnel portion at a vehicle width direction center portion at a lower end portion,
The engagement portion overlaps with the tunnel portion at a position in the vehicle body width direction,
The rear extension member extends rearward from the dash panel through the tunnel portion;
The engagement portion and the rear extension member are respectively disposed on the inner side in the vehicle width direction away from a seal portion that seals the toe board through which the steering shaft passes .

According to a second aspect of the present invention, there is provided a vehicle front structure according to the first aspect of the present invention.
The rear extension member is an exhaust pipe of an engine;
An insulator is interposed between the cover member that covers the steering shaft and the exhaust pipe.

According to a third aspect of the present invention, there is provided a vehicle front structure according to the second aspect of the present invention.
The insulator is attached to a case that houses the translation member.

According to a fourth aspect of the present invention, there is provided the vehicle front structure according to the second or third aspect of the invention.
The cover member is a cylindrical member that covers the steering shaft,
The insulator includes a side covering portion that covers the cover member from the vehicle width direction inner side and a front covering portion that covers the cover member from the vehicle body front side.

Further , the region occupied by the engaging portion between the lower end portion of the steering shaft and the translation member in the vehicle body width direction overlaps the region occupied by the rear extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engaging portion is located. As a result, the connecting portion between the translation member and the tie rod can be arranged more effectively closer to the inner side in the vehicle body width direction, so that the above-described suppression of bump steer can be realized more effectively.

According to the second aspect of the present invention, the lower end side portion of the steering shaft is disposed close to the exhaust pipe of the engine, and the exhaust pipe is provided by the insulator interposed between the cover member covering the steering shaft and the exhaust pipe. Since the heat is blocked, the cover member can be protected from heat damage.

Omitted by applying the invention described in claim 3 in the invention of claim 2, since the insulator is attached to the case housing the translation member, the cover member, the protruding portion of the boss portion or the like for the insulator mounting be able to. Therefore, it becomes easy to arrange the insulator close to the cover member, and this facilitates the arrangement in which the exhaust pipe and the engaging means are overlapped in the vehicle body width direction as described above.

When the invention according to claim 4 is applied to the invention according to claim 2 or claim 3 , the cylindrical cover member is covered with an insulator from the vehicle body width direction inner side and the vehicle body front side, whereby the cover member Can be more effectively suppressed.

Claims (5)

A steering shaft extending in a direction inclined toward the vehicle body lower side toward the vehicle body front side, and is engaged with a lower end portion of the steering shaft via predetermined engagement means to rotate around the axis of the steering shaft. A translation member that translates along the vehicle body width direction in conjunction with the vehicle body, a knuckle that supports a steering wheel, a lower arm that couples the knuckle to a subframe, a tie rod that couples the knuckle to the translation member, and the translation member A rear extension member extending from the front side portion of the vehicle body to the rear side of the vehicle body, and sandwiching the vehicle center in the vehicle body width direction at the vehicle longitudinal direction position where the engaging portion between the lower end portion of the steering shaft and the translation member is located It is a vehicle front structure in which the engagement means and the rear extension member are arranged on the same side,
The lower arm and the tie rod are disposed substantially in parallel when viewed from the front-rear direction of the vehicle body,
The region occupied by the engaging means in the vehicle body width direction overlaps the region occupied by the rearward extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engaging portion between the lower end portion of the steering shaft and the translation member is located. The vehicle front part structure characterized by the above-mentioned.   The region occupied by the engagement portion between the lower end portion of the steering shaft and the translation member in the vehicle body width direction overlaps the region occupied by the rear extension member in the vehicle body width direction at the vehicle body longitudinal direction position where the engagement portion is located. The vehicle front part structure according to claim 1, wherein The rear extension member is an exhaust pipe of an engine;
The vehicle front part structure according to claim 1 or 2, wherein an insulator is interposed between the cover member that covers the steering shaft and the exhaust pipe.   The vehicle front structure according to claim 3, wherein the insulator is attached to a case that accommodates the translation member. The cover member is a cylindrical member that covers the steering shaft,
The said insulator is provided with the side coating | coated part which coat | covers the said cover member from the vehicle body width direction inner side, and the front coating | coated part which coat | covers the said cover member from the vehicle body front side. 4. The vehicle front structure according to 4.

Images