JPS6251186B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a vehicle steering system that steers both the front wheels and the rear wheels.

The present applicant has previously provided a vehicle steering device in which front wheels and rear wheels can be steered by steering operation of a steering wheel. Basically, such a device connects the front wheel steering mechanism and the rear wheel steering mechanism with a linkage member such as a linkage shaft, and moves the rear wheels in the same direction as the front wheels by operating a small steering angle of the steered wheels. In addition, a steering angle function generating mechanism is configured to steer the vehicle in the opposite direction in the case of a large steering angle operation, or to return the steering angle of the rear wheels to zero in the latter case.

By the way, in this type of vehicle, the rear wheels are independently suspended, and the lower arms that make up the rear wheel suspension mechanism may be lengthened depending on the suspension characteristics. In this case, the bearings of the left and right lower arms are placed near the center line of the vehicle body.
Therefore, the tie rods for steering the left and right rear wheels are also disposed opposite to each other near the center line of the vehicle body, and therefore, it is desirable to make the rear wheel steering mechanism more compact, especially in the vertical direction from the viewpoint of the vehicle body structure.

Furthermore, if each component that makes up the rear wheel steering mechanism can be assembled into so-called sub-assemblies (small assemblies) as much as possible and installed on the car body, it will be advantageous in terms of installation workability, and moreover, it will be possible to perform particularly high-precision machining on the car body side. It can also be expected to have an advantage in terms of workability, since it is not necessary to apply.

The present invention has been made to achieve the above-mentioned compactness and subassembly at once, and its purpose is to improve the shaft of a rear wheel steering mechanism that is connected to the front wheel steering mechanism via a linkage member. The member is inserted into a cylindrical shaft holder that rotatably holds the member, and the crank pin of the crank part provided on the shaft member is connected to tie rods for steering the left and right rear wheels, and a link member suspended from the vehicle body. The shaft holder is attached to a cylindrical shaft collar fixed to the vehicle body by loosely fitting and pre-assembling the joint member which is fixedly supported by the arm member which is pivotally connected to the cylindrical shaft collar. It is an object of the present invention to provide a steering device for a vehicle that is intended to improve processing and installation workability by inserting and attaching the steering device, and can be disposed compactly in the vertical direction.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that FIG. 1 is an explanatory front view of a four-wheeled vehicle equipped with the steering system of the present invention, and FIGS.
The figures are a side view and a rear view, and FIG. 4 is an enlarged perspective view showing the basic configuration of the main parts according to the present invention.

The steering rotation of the steering wheel 1, which is a steering wheel, is converted to the left and right movement of the tie rods 4, 4 for steering the front wheels 3, 3 via a rack-and-pinion type steering gear 2 equipped with power steering. Knuckle arms 5, 5 connected to the outer ends of
The front wheels 3, 3 are also steered by this rotation.

A linkage member 6 is connected to approximately the center of the steering gear 2, and a linkage shaft 9 is extended to the rear of the vehicle body via a universal joint 8 to a pinion shaft 7 that easily meshes with it, and is further extended to the rear via a universal joint 10. Ring 11,1
A shaft member 12 constituting one steering mechanism is connected.

The shaft member 12 is disposed on the main center line of the vehicle body with its rear end facing downward, and a crank portion 13 is provided at the rear end thereof, and a crank pin 14 of the shaft member 12 is formed to protrude rearward. Such shaft member 1
2 is inserted and supported within a shaft collar 16 that is fixedly integrated with a rear wheel lower arm bracket 15 provided on a cross member of the vehicle body frame.

That is, as shown in FIG. 5, between the shaft collar 16 fixed to the bracket 15 and the shaft holder 17 of the shaft member 12 supported within this 16, there are two front and rear parts as shown in FIG. Rubber bushes 18 and 19 are interposed, and the shaft holder 17 is press-fitted into the shaft collar 16 via these rubber bushes 18 and 19. In this way, the shaft member 12 is rubber-mounted to the vehicle body and is therefore supported in a floating manner.

5 and 6, the direction in which the cross section of the shaft collar 16 is shown is reversed.

A joint member 20 having an approximately inverted T shape in the front is loosely fitted into the crank pin 14 of the crank portion 13 provided on the shaft member 12 with its upper part 21, and protrusions 2 forming lower portions on both left and right sides of this joint member 20.
Rear wheel steering tie rods 23, 23 are provided with ball joints 24, 24 on the upper surfaces 22a, 22a of the wheels 2, 22, respectively.

On the other hand, a ring bracket 25 is fixedly suspended from a portion rearward of the joint member 20 on one side of the floor panel of the vehicle, and a link member 26 is attached to this 25.
is suspended from a pivot. An arm member 27 is pivotally attached to the lower part of the link member 26.
is formed sufficiently long beyond the center line of the vehicle body, and both left and right protrusions 22 of the joint member 20,
The tip portion 27a of the arm member 27 is fixed to the rear surface portions 22b, 22b of the arm member 22 with two bolts 28, 28. As a result, the joint member 20 performs a combined rocking motion of vertical and horizontal movements in conjunction with the crank movement of the crank pin 14.

In the figure, 29 is a knuckle arm connected to the outer end of the tie rod 23 for steering the rear wheels, and 30 is a lower arm for the rear wheels.

In the present invention, the shaft member 12, joint member 20, etc. are made into a sub-assembly and attached to the vehicle body. This will be explained in detail based on FIG. 7, which is an exploded perspective view, and FIGS. 5 and 6.

As described above, the shaft collar 16 is fixedly attached to the rear wheel lower arm bracket 15, which is a cross member of the vehicle body frame, and is located on the center line of the vehicle body, with its rear portion downwardly inclined. A mounting seat portion 31 is formed on the outer periphery of the rear end of the cylindrical shaft collar 16, and the mounting seat portion 31 extends radially in the outer diameter direction.
one piece 31a at the bottom, one piece 3 each at the left and right upper sides.
It has mounting pieces 1b and 31b.

The tip of the cylindrical shaft holder 17, which is inserted into the shaft collar 16 and rotatably holds the shaft member 12, has a large inner and outer diameter 17a.
A flange portion 32 is formed on the outer periphery of the large-diameter tip portion 17a near the tip. A flange portion 33 is further formed on the rear outer periphery of the large-diameter tip portion 17a at a slight distance from the large-diameter tip portion 17a, and the rear portion of the shaft holder 17 is also formed to have a large diameter 17b like the tip portion. A positioning piece 34 is formed near the rear end of the outer periphery of the radial rear portion 17b. The positioning piece 34 consists of three radial pieces.

The rear portion of the shaft member 12 is formed to have a large diameter 12a, a flange portion 35 is formed at the rear end of the large diameter rear portion 12a, and a crank portion 13 is further formed on the rear surface of the flange portion 35. The crank portion 13 consists of a flange portion 36 eccentric to the shaft member 12, and a crank pin 14 protruding from the rear surface of the flange portion 36. The rear end portion of the crank pin 14 is provided with a female screw portion 14a, and a diameter A hole 14b is formed to penetrate in the direction.

The joint member 20 that is loosely fitted onto the crank pin 14 is formed into a generally inverted T-shape from the front with a low height.
The upper part 21 has a large-diameter crank pin insertion hole 37 formed through it in the front-rear direction, and the protrusions 22, 22 forming the lower portions on both left and right sides have small-diameter ball joint pin holes formed through it in the vertical direction. 38, 38
It also has small-diameter arm member attachment holes 39, 39 formed to penetrate in the front-rear direction inwardly from these 38, 38.

As shown in FIG. 6, first the shaft holder 1 is
Bearings 40 and 41 are fitted into the large-diameter front and rear parts 17a and 17b of No. 7, respectively, and the shaft member 12 is inserted into the holder 17 so that the outer periphery of the shaft member 12 protrudes forward from the tip of the holder 17. The washer 42 is installed, the circlip 43 prevents the thrust movement of the washer 42, the washer 42 is brought into contact with the distal end surface of the holder 17, and in this state, the seal cap 44 is inserted from the front to the flange portion 32 near the distal end of the holder 17. to be crowned. At this time, the rear end flange portion 35 of the shaft member 12 is slightly separated from the rear end surface of the holder 17.

A seal ring 45 is attached to the flange portion 36 of the crank portion 13 from behind the rear end flange portion 35 of the shaft member 12, and a bearing 4 is attached to the crank pin 14.
6 are respectively attached, and the crank pin 14 is inserted into the insertion hole 37 of the upper part 21 of the joint member 20 via the bearing 46. A washer 47 is attached to the rear part of the crank pin 14 that protrudes to the rear of the joint member 20, and a nut 48 is screwed onto the female threaded portion 14a to bring the washer 47 into contact with the periphery of the insertion hole 37 of the joint member 20. The split pin 49 is inserted and locked into the hole 14b provided at the rear end of the crank pin 14, and the seal cap 50 is further fitted onto the upper part 21 of the joint member 20 from the rear.

The assembly member consisting of the shaft member 12, shaft holder 17 and joint member 20, which have been assembled in advance into a sub-assembly, is attached to the vehicle body in the following manner.

First, a seal ring 51 different from the one described above is installed from the front across the rear end flange portion 35 of the shaft member 12 and the rear end of the large diameter rear portion 17b of the shaft holder 17, and then the three mounting pieces 52a are attached radially. The mounting member 52 having the above-mentioned structure is attached to the outer periphery of the tip of the seal ring 51. The mounting member 52 has a central portion that is concave 5 to the rear.
3 is formed, and the recessed portion 53 accommodates the rubber bushing 19 described below and prevents its rotation.

Next, two rubber bushings 18 and 19 are attached to the outer periphery of the shaft holder 17 at the front and rear.

A small diameter portion 19a is formed on the inner periphery of the tip of the rear rubber bush 19, and a large diameter portion 54 for positioning is formed in the rear half.
It consists of The large diameter positioning portion 54 is formed to be sufficiently larger than the positioning piece 34 of the shaft holder 17, and an engagement groove 54a is formed on its inner periphery. It is formed in a shape having notches 54b.

Further, a small diameter portion 18a is formed from the inner periphery of the tip of the front rubber bush 18 to the inner periphery of the rear end.
a is engaged between the large-diameter tip 17a of the shaft holder 17 and the flange 33 at the rear thereof.

Then, attach the shaft holder 17 to the rubber button 1.
8, 19 into the shaft collar 16 from the rear, and bring the mounting pieces 52a of the mounting member 52 into contact with the mounting pieces 31a, 31b... of the mounting seat 32 on the outer periphery of the rear end of the collar 16, respectively. Combine at... In this case, as shown in FIG. 8, the positioning piece 34 of the shaft holder 17 abuts against the mounting seat 31 of the shaft collar 16 via the positioning large-diameter portion 54 of the rear rubber bush 19 to achieve positioning.

Thereafter, as described above, attach the left and right rear wheel tie rods 23, 23 to the joint member 20 at the ball joint 2.
4, 24, and then the arm member 27 is tied to the joint member 20, completing the assembly of each component of the rear wheel steering mechanism.

The operation of the above-mentioned steering system will now be described. First, when the steering wheel 1 is in the neutral position when the vehicle is moving straight, the crank portion 13 is in a vertical position with the crank pin 14 facing downward, for example.

For example, when steering wheel 1 is steered to the right, front wheel 3
is similarly steered to the right, and the shaft member 12 rotates clockwise as seen from the rear of the vehicle via the linkage member 6 consisting of the pinion shaft 7 and linkage shaft 9 derived from the steering gear 2. . As a result, the crank pin 14 of the crank portion 13 similarly rotates clockwise, and the joint member 20 loosely fitted onto the pin 14 first swings to the left. Therefore, the tie rods 23, 23 connected to both the left and right protrusions 22, 22 of the joint member 20, which forms a substantially inverted T-shape from the front, move to the left, the knuckle arms 29, 29 rotate clockwise, and the rear wheel 11 moves toward the front wheel 3. At the same time, the ship is steered to the right.

The right steering amount of the rear wheel 11 is maximum when the crank pin 14 becomes horizontal to the left, and thereafter the joint member 20 swings to the right until the pin 14 becomes vertically upward. The right steering amount of the wheel 11 is gradually reduced to zero.

When the pin 14 further cracks clockwise, the joint member 20 swings further to the right from the neutral position, and the rear wheel 11 then moves to the left in the opposite direction to the front wheel 3 until the pin 14 becomes horizontal to the right. The steering wheel is steered with a gradually increasing amount of steering.

Then, the joint member 20 swings leftward until the pin 14 reaches the downward vertical position again, exceeding the above-described state in which the left steering amount is at its maximum.
The left steering amount gradually decreases to zero. The left steering is done in the same way.

In this way, a small steering angle operation of the steered wheel 1 (up to 180 degrees with the neutral position of the crank pin 14 set at 0 degrees) causes the rear wheel 11 to move in the same direction as the front wheel 3, and a large steering angle operation (from 180 degrees to 360 degrees) 2), a steering angle function generating mechanism was constructed that can steer the vehicle in the opposite direction, or in the latter case, return the steering angle of the rear wheels 11 to zero.

Moreover, the vehicle steering system of the present invention capable of generating the above-mentioned steering angle function has a joint member 20 loosely fitted to the crank pin 14, which is a small component with a substantially inverted T-shape when viewed from the front.
Make a mold, and hold this 20 at the upper part 21 and attach it to the pin 1.
4, and the upper surface portion 2 of the protrusions 22, 22 forming the lower portions of the left and right sides of the joint member 20.
Tie rods 23, 23 for rear wheel steering are attached to 2a and 22a.
are connected to each other, and further the rear surface 2 of the protrusions 22, 22 is connected to each other.
An arm member 27 is connected to 2b and 22b, and the arm member 27 is pivotally supported by a link member 26 hanging biased toward the rear part of the joint member 20 on one side of the floor panel of the vehicle. .

Therefore, the lower arm 30 that constitutes the rear wheel suspension mechanism
is made longer depending on the suspension characteristics, so the bearings of the left and right lower arms 30, 30 are placed near the center line of the vehicle body,
Along with this, tie rods 23, 23 for rear wheel steering
They can also be compacted and placed facing each other near the centerline of the vehicle body, and compactness in the vertical direction, which is particularly desirable from the standpoint of vehicle body structure, can be achieved.

In particular, in the present invention, the shaft member 12, the shaft holder 17, and the joint member 20 are made into a sub-assembly and assembled in advance, and then the assembly member is inserted into the shaft collar 16 fixed to the vehicle body for installation, making installation easy. This is extremely advantageous in terms of installation workability, and since it is no longer necessary to individually attach each component to the vehicle body, there is no need for special precision machining on the vehicle body. It is also very convenient in terms of workability.

Although not shown in the drawings, since rubber bushings are interposed at each pivot point between the link member 26, the bracket 25, and the arm member 27, the vibration-proofing effect is excellent in combination with the rubber mount of the shaft member 12. In addition, the joint member 20 is composed of a small part with a generally inverted T-shape when viewed from the front, and an arm member 27, which is a member that ensures the rocking of the joint member 20, is suspended from the vehicle body with an offset toward the rear on one side of the joint member 20. Since the joint member 20, which requires great strength, can be reliably miniaturized, a large load is not applied to the arm member 27, which is a large component, so that it has sufficient strength. It is possible to achieve a thinner wall without having to reduce the thickness of the device, and it is also possible to reduce the weight of the entire device.

As is clear from the above description, according to the present invention, the rear wheel steering mechanism can be arranged compactly without taking up space in the vertical direction, and each component is assembled into sub-assemblies as much as possible and installed on the vehicle body. It is extremely advantageous in terms of installation workability,
Furthermore, it is possible to exhibit many advantages such as ease of processing in terms of workability.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory plan view of a vehicle equipped with the steering system of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a rear view of the same, and FIG.
The figure is an enlarged perspective view showing the basic configuration of the main parts according to the present invention, FIG. 5 is a vertical sectional side view of the shaft collar attachment part, FIG. 6 is a partially cutaway side view of the shaft member assembly part, and FIG. 7 is a FIG. 8 is an exploded perspective view of the assembly member and an enlarged longitudinal sectional view of the positioning structure. In the drawing, 1 is a steering wheel, 3 is a front wheel, 11 is a rear wheel,
12 is a shaft member, 13 is a crank portion, 14 is a crank pin, 16 is a shaft collar, 17 is a shaft holder, 20 is a joint member, 23 is a rear wheel steering tie rod, 26 is a link member, and 27 is an arm member.

Claims (1)

[Claims] 1. A steering device for a vehicle in which front wheels and rear wheels are steered by steering operation of a steering wheel, which includes a shaft member that rotates in conjunction with the steering wheel, and a cylindrical shaft member that rotatably holds the shaft member. It is loosely fitted into the shaft holder and the crank pin of the crank part provided on the shaft member, connects the left and right rear wheel steering tie rods, and is further tied to an arm member that is pivotally supported by a link member suspended from the vehicle body. A steering device for a vehicle, characterized in that the shaft holder is inserted into a cylindrical shaft collar in which joint members to be supported are assembled in advance and these assembled members are fixed to a vehicle body.