JPH0726173Y2 - Front suspension for ultra low floor vehicles - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a front suspension of an ultra-low floor vehicle, particularly,
The present invention relates to a front suspension equipped with an air spring and a link system.

(Prior Art) Vehicles, particularly city route buses, are being made lower in floor and widening the entrances at the front and rear sides of the vehicle body for the purpose of facilitating getting on and off.

By the way, among the front body structures of medium- and large-sized vehicles such as buses, those of the suspension type are configured as shown in FIGS. 5 and 6, for example.

Here, the front axle 1 which is long in the vehicle width direction is attached to the vehicle body via, for example, an air spring type suspension, and the front wheels 3 are pivotally supported by knuckles 2 at the left and right ends thereof.

This air spring type suspension is connected to the left and right front side members 5 via a pair of air springs 4 arranged on the left and right of the central straight portion of the front axle 1. Further, a protruding bracket 6 extending upward is attached to the center of the front axle 1 here, and left and right brackets 7 are attached to the left and right of the axle, respectively.

The upper part of the projecting bracket 6 and the left and right brackets 7 are respectively pin-coupled to the respective frontwardly extending apparadias rods 8 and the left and right lower radius rods 9, and the tips of the rods are respectively pinned to the vehicle body base side. It constitutes the leverage mechanism. Further, one end of a lateral rod 10 extending in the vehicle width direction is pin-connected to the rear wall surface of the protruding bracket 6, and the other end is pin-connected to the vehicle body base.

A floor member 11 of a vehicle equipped with such an air spring type suspension is attached to the upper surfaces of the brackets 7 of the left and right front side members 5, and a floor surface F is formed on the floor member 11.

(Problems to be solved by the invention) By the way, in the case of a vehicle equipped with a front suspension as shown in FIG. 5, the straight portion 12 of the front axle 1 is curved sufficiently lower than its left and right ends, Thus, the height H1 of the floor member 11 from the road surface is kept low. However, even in this case, the height H1 from the road surface is regulated by the vertical widths of the protruding bracket 6, the upper radius rod 8, the left and right lower radius rods 9, the pair of left and right air springs 4, and the left and right front side members 5, respectively. Could not be placed at a sufficiently low position. That is, even in this case, the occupant from the entrance / exit reaches the floor surface F by climbing the two steps, and there is a problem in the entry / exitability.

An object of the present invention is to provide a front suspension for an ultra-low floor vehicle that allows the floor surface of the vehicle to be formed relatively low.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention is directed to a straight portion that is longer than a space between a pair of left and right front side frames of a vehicle. A front axle having a pair of vertically elongated columns and a pair of left and right knuckle support portions that extend to the vehicle side end side from the vertically elongated columns and pin-connect each left and right knuckles, and a mounting base at the upper end of the vertically elongated columns and the vehicle. An air spring mounted between the rigid base materials of the tire house, upper and lower mounting projections projecting from the vertically long pillars, and upper and lower mounting brackets on the vehicle body side located in front of the vertically long pillars to form a double lever mechanism. A long rail in the vehicle width direction in which one end is connected to the front facing surface of the front axle and the other end is pin-coupled to the bracket on the vehicle body side, respectively, which are connected to the upper side rod and the lower side rod to be connected. It is characterized by adopting a structure having a teral rod.

(Operation) The straight portion of the front axle is formed to be longer than the distance between the pair of left and right front side frames of the vehicle, and the pair of left and right vertically elongated columns are formed to extend vertically from the left and right ends of the straight portion.
Since the upper end of the straight part was attached to the rigid base material of the tire house of the vehicle via the air spring, and the upper and lower positions were connected to the upper and lower mounting brackets on the vehicle body side via the upper radius rod and the lower radius rod. The front axle can be arranged directly under the pair of front side frames, and the front side frame and the floor member attached thereto can be arranged at a relatively low position.

(Embodiment) The front suspension of the ultra-low floor vehicle shown in FIGS. 1 to 4 is mounted on the front part of the route bus.

The body of this route bus has a frameless structure in which the body of the body is formed by a well-known stress skin structure. A member corresponding to a frame for transmitting an input to the side structure side of the body is integrally welded to the lower portion of the body.
That is, this frame-equivalent member is composed of a plurality of auxiliary frames (not shown) that support a floor material that is long in the vehicle width direction, left and right front side frames 20R, 20L, left and right rear side frames, and the like.

Here, the left and right front side frames 20R, 20L are respectively formed by sequentially connecting the front and rear continuous frame constituent members integrally. The right front side frame 20R side is continuously formed by a main frame member 201 that is uniformly long before and after the tire house T, and the left front side frame 20L is relatively short main frame member 201 and the same main body member before and after the tire house T. Frame member 2
A low position frame member 202 is integrally formed with the front end of 01 and the rear end of itself.

The tire house T of the vehicle is a rigid member that secures a box-shaped space.
The main part of the box-shaped space is formed by 22, 22 ..., In particular, the inner wall surface of the upper corner of the tire house is formed by a reinforcement 23 having a long U-shaped cross section in the front and rear. A box-shaped bracket 24 is integrally welded to the center of 23 so as to project outward, and the lower surface thereof is formed as a mounting portion for an air spring 26 described later.

A front axle 25, which is long in the vehicle width direction and pivotally supports front wheels 21 at the left and right ends, is arranged at the front of the vehicle body of this route bus, which is attached to the vehicle body base via an air suspension A,
Moreover, the left and right front wheels 21 have the power steering mechanism S
It is configured to be steered by (see FIG. 2).

The front axle 25 includes a straight portion 251 located in the center of a straight shape longer than a pair of left and right front side frames L, and a pair of left and right vertically elongated pillars each extending upward from both side ends of the straight portion 251. 252 and a pair of left and right knuckle support portions 253 that extend to the vehicle-side end side from the vertically long columns 252 and that pin-connect the left and right knuckles 27, respectively. Moreover, each of the vertically long columns 252 is arranged in the tire house T of the vehicle, and a disc-shaped mounting base 254 is provided at the upper end thereof, and upper and lower mounting projections 255, 256 projecting vertically from the front wall of the mounting base 254, respectively. The extension is formed, and these are integrally cast. The front axle 25 may be integrally formed by forging.

In this vehicle body, the floor member 28 is attached to the frame equivalent member,
A floor surface F is formed on the floor member 28. Especially, the floor member 28 in the area facing the front side frames 20L, 20R.
Is the left front side frame 20L as shown in Fig. 1.
The floor surface F is formed so as to spread horizontally evenly over the upper position (the front end of which is constituted by the low-position frame member 202) and the lower position of the right front side frame 20R. Therefore, the step-facing floor surface F1 facing the entrance 29 at the front left of the vehicle has a height H2 from the road surface so that the passenger can easily reach the floor surface F through the first step 30. Is secured.

The pair of left and right vertically long columns 252 of the front axle 25 are disposed directly below the tire house T, and the lower portion of the air spring 26 is bolted to the mounting base 254 at the upper end thereof. The upper portion of the air spring 26 is fixed to the box bracket 24.

The upper and lower mounting projections 255, 256 projecting from the vertically long pillar 252 of the front axle 25 are respectively pin-coupled to the upper radius rod 31 and the lower radius rod 32, and the tips of the rods are respectively pin-coupled to the downward bracket 33 on the vehicle body base side. Thus, the vertically long column 252 is configured to form a double lever mechanism.

Here, both the upper radius rods 31 and the lower radius rods 32 are arranged in the tire house T at the outer sides of the front side frames 20L and 20R.

One end of a lateral rod 34 extending in the vehicle width direction is pin-connected to a portion of the front axle 25 facing the left front side frame 20L, and the other end is pin-connected to a vehicle body base via a bracket 35. Incidentally, reference numeral 36 indicates a shock absorber, by which the exciting force applied to the front axle is attenuated.

The upper radius rod 31 and the lower radius rod 32, the lateral rod 34, the air spring 26 and the shock absorber 36 cooperate with each other so that the front axle
Acts as an axle suspension type air suspension A that supports 25.

Power steering mechanism S for steering the left and right front wheels 21
Is configured so that the steering received by the steering wheel 37 is boosted by a power steering booster (not shown) and is transmitted to the drag link 39 via a pitman arm (not shown). this. The drag link 39 is composed of a pair of front and rear rod-shaped members that are connected to each other at the center via an intermediate lever 40, and the rear end thereof is connected to the central arm portion 443 on the right front wheel 21 side via a ball joint 42.

The knuckle 27 on the right front wheel 21 side is pin-connected to the bearing portion at the projecting end of the knuckle support portion 253 by a king pin (not shown), and a tie rod arm 44 is bolted to the inner surface of the lower portion thereof. The tie rod arm 44 is composed of a base portion 441, a rear arm 442 extending rearward from the base portion, and a central arm 443 extending from the center of the base portion to the vehicle center, and is integrally formed as a forged product. A tie rod 45 is connected to a tip end of the rear arm 442 via a ball joint 46.

A knuckle 43 on the left front wheel 21 side (see FIG. 4) has a shape in which the central arm is removed from the tie rod arm on the right front wheel 21 side, that is, a tie rod arm 44 including a base 441 ′ and a rear arm 442 ′ is bolted. Cage, rear arm 442 '
A tie rod 45 is connected to the projecting end of the through a ball joint 46.

A vehicle equipped with such a front suspension of an ultra-low floor vehicle. When the vehicle is running, the air suspension A acts to buffer an excessive input from the road surface and ensure a good riding comfort for the occupant. Further, the left and right front wheels 21 are relatively easily steered by the power steering mechanism S, the steering angles of the front wheels 21 can be easily operated, and the vehicle can be turned in a desired state.

In this case, especially the left and right front side frames 20L, 20R
Is formed so that the height H1 from the road surface is sufficiently low,
The height H2 of the floor surface F from the road surface can be made relatively low, and the occupant can easily reach the floor surface F through the first step 30.

Moreover, the front axle 25 does not have any member projecting upward on the straight portion 251 thereof, so that interference with the front side frames 20L, 20R having a relatively low height H3 from the road surface is reliably prevented. There is. In addition, the Apparatus rod
Both the 31 and the lower radius rod 32 are arranged long outside of the front side frames 20L and 20R in the front-rear direction, and the main parts thereof can swing in the tire house T without vertically interfering with each other.

Moreover, the air spring 26 is disposed substantially in the center of the inside of the tire house T (see FIG. 2), and the same position is a dead space that does not originally interfere with the turning trajectory of the wheel 21, and the same portion is effectively used. Therefore, the problem that the passenger compartment space is reduced in order to secure the accommodation space for the air spring 26 is prevented.

On the other hand, the steering angle operation force from the drag link 39 is transmitted to the central arm 443 on the right front wheel 21 side, and via the same portion, the left front wheel 21.
It is transmitted to the side via a tie rod 45. In this case, the central arm 443 can rotate in a space below the knuckle support portion 253 on the vehicle side end side of the vertically long column 252 and in a position where the height from the road surface is higher than the straight portion 251 and that portion interferes with the road surface. Are prevented from doing so.

(Effects of the Invention) As described above, according to the present invention, the straight portion of the front axle is formed longer than the left and right front side frames, and the members protruding above the same are not attached. The frame and floor member can be arranged at a relatively low position, the floor surface can be made low, and getting on and off can be facilitated. Moreover, the distance between the pair of air springs can be made relatively wide, and the rolling regulation characteristic of the vehicle can be improved. It also has the advantage of being excellent.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a front suspension and a steering system of an ultra-low floor vehicle as an embodiment of the present invention, and FIG. 2 is a plan view of a main part of the same suspension and a steering system as seen through a floor surface. FIG. 3 is a side view of a main part of the suspension and steering system, FIG. 4 is a rear view of the main part of the suspension and steering system, FIG. 5 is a perspective view of a main part of a conventional front suspension, and FIG. FIG. 3 is a schematic front view of a main part of the front suspension of FIG. 20L, 20R …… Front side frame, 21 …… Front wheels, 2
5 …… Front axle, 26 …… Air spring, 27
...... Knuckle, 28 …… Floor member, 31 …… Apparatus rod, 32 …… Lower radius rod, 251 …… Straight section, 252
…… Vertical pillar, 253 …… Knuckle support, 33 …… Downward bracket, 34 …… Lateral rod.

Claims (1)

[Scope of utility model registration request] 1. A straight portion that is longer than a distance between a pair of left and right front side frames of a vehicle, a pair of left and right vertically elongated columns that extend from the left and right ends of the same straight portion and that are vertically long, and closer to the vehicle end than the vertically elongated columns. A front axle having a pair of left and right knuckle support portions for pinning out each of the left and right knuckles, an air spring attached between a mounting base at the upper end of the vertically long pillar and a rigid base material of a vehicle tire house, and The upper and lower mounting projections projecting from the vertically long pillars and the upper and lower mounting brackets on the vehicle body side located in front of the vertically long pillars are connected so as to form a double lever mechanism. A front support for an ultra-low-floor vehicle having a lateral rod that has one end on the surface and the other end that is pin-connected to the bracket on the vehicle body side and is long in the vehicle width direction. Pension.