JPS619376A - Front and rear wheel steering system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a steering device for front and rear wheels of a vehicle.

(Prior Art) In the four-wheel steering system of a vehicle, the present applicant has filed a patent application as one of the so-called symmetrical function type steering systems in which the rear wheels have the same maximum steering angle as the front wheels in the same phase and in the opposite phase. Showa 57-933
No. 94 (Japanese Unexamined Patent Publication No. 58-209657). In this steering system, a joint member that connects and supports the left and right rear wheel tie rods is rotatably fitted onto an eccentric shaft installed at the rear end of the input shaft of the rear wheel steering system, which rotates in conjunction with the steering wheel. Furthermore, this joint member is supported on the vehicle body via a link mechanism to restrict the swinging of the joint member.

In addition, prior to this, the present applicant had filed a patent application No. 56-12718.
No. 8 (Japanese Unexamined Patent Publication No. 58-30869) proposes a steering system in which the eccentric shaft and a joint member are slidably engaged, and the joint member can only be moved in the left-right direction. (Problems to be Solved by the Invention) The steering system disclosed in Japanese Patent Application No. 57-93394 has the following technical problems.

First of all, since a link mechanism is used to restrict the swing of the joint member, it is necessary to take up space for this, making the device as a whole difficult to compact, making it difficult to check performance before assembling it into a vehicle, and making it difficult to attach the link to the vehicle body. Installation is difficult both in terms of strength and precision. In addition, since a link mechanism that extends to one side of the vehicle body is used, the structure is asymmetrical, and the relationship between the rotation of the input shaft and the left-right position of the ball joint is slightly different between counterclockwise and clockwise rotations, so the left and right steering angle is Causes errors in changes.
) Specifically, the rear wheel tie rods are connected to the left and right sides of the joint member via ball joints.
Since the joint member performs a combined movement in the left-right and up-down directions, the ball joint also moves up and down, which causes an error in setting the rear wheel steering angle. Also, if the ball joint is placed far from the center of the joint member, the force applied to the link mechanism will increase, increasing the strength.
Due to rigidity limitations, there are restrictions when determining the position of the ball joint to match the suspension, making it difficult to freely combine it with various types of suspension.

Furthermore, since the input shaft and the joint member are all sliding in the thrust direction, friction is large, accuracy is difficult to achieve, play is unavoidable, and there is a possibility of the occurrence of hitting noise.

In addition, the clearance of all roller bearings used for input shafts, eccentric shafts, and joint member bearings cannot be adjusted, so strict precision is required to assemble without play, resulting in high costs and long processing and inspection times. .

Furthermore, since the input shaft is supported by a relatively thin holder attached to the vehicle body, force is concentrated and soft mounting rubber cannot be used, making it difficult to insulate sound and vibration.

On the other hand, according to the steering system disclosed in Japanese Patent Application No. 56-127188, since the circumference of the eccentric shaft is directly engaged with the joint member, precision is required for alignment, and in particular, the occurrence of clearance in the radial direction at the engagement part is avoided. There are technical issues that make it difficult.
- The present invention has been made to solve the technical problems in both of the above-mentioned steering systems, and the objective of the first invention, which is the specific invention, is to simultaneously provide the advantages of both steering systems, that is, to make the device compact as a whole. In addition to eliminating errors in left and right steering angle changes and set steering angles, and adapting to various types of suspensions, automatic alignment of the eccentric shaft and joint member is achieved, and the use of soft mount rubber It is an object of the present invention to provide a steering device for front and rear wheels that is usable, is advantageous in blocking noise and vibration, and has excellent practicality, such as being able to adjust the assembly of an input shaft and a joint member.

A second invention having the first invention as a main part further provides a steering device for front and rear wheels that can maintain zero clearance between an input shaft and a joint member during long-term use. purpose.

(Means for Solving the Problems) Accordingly, in the first aspect of the present invention, an eccentric shaft (22) is provided at the rear end of an input shaft (20) of a rear wheel steering system that rotates in conjunction with a steering wheel. and left and right rear wheel tie rods (15),
(15), and slidably engages with a joint member (30) supported by the vehicle body so as to be horizontally movable in the left-right direction. ) and the joint member (30), the tapered engaging portion ( 37), and the input shaft (
20) is characterized in that it is provided with an adjusting means for adjusting the position in the front-rear direction.

Specifically, the adjustment means includes angular bearings (28), (29), and (123) interposed between the input shaft (20) and its bearing holder (42), and the bearing holder (
42), a sleeve (142) screwed into the interior of the
50), (150), and thrust washers (51), (151) interposed between this sleeve and the outer rings (29), (125) of the bearing.

Furthermore, a second invention is characterized in that, in addition to the configuration of the first invention, a preload means for urging the input shaft (20) toward the joint member (30) is provided.

Specifically, the preload means includes the sleeve (50),
(150) and the washers (51), (1
Coil springs (52), (51) that push the
152).

(Function) In this way, since the eccentric shaft (22) and the joint member (30) are slidably engaged at the left and right taper engaging portions (37), the centripetal action of the tapered engaging portions (37) automatically Center alignment can be performed, and high accuracy can be maintained especially in changing the left and right steering angle of the rear wheels and setting the steering angle.

Since the adjustment means for adjusting the position of the input shaft (20) in the front and back direction is provided, the input shaft (20) can be moved backward and adjusted to properly initialize the engagement state of the tapered engagement portion (37). .

Furthermore, since a preload means is provided to urge the input shaft (20) in the direction of the joint member (30), the engagement state of the tapered engaging portion (37) can be maintained properly at all times by the pressing force. The clearance of the tapered engaging portion (37) during use can be maintained at zero in both the radial and thrust directions.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a steering angle function generating mechanism of a rear wheel steering system showing the main part of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-II.
FIG. 4 is a schematic perspective view of the entire steering system.

As shown in Figure 4, the support shaft (2) of the handle (1) is built into a rack and pinion gearbox (3), and tie rods (5) are connected to both ends of the rack shaft (0). ,
Tie rods (5), (5,) have front wheels (7), (7)
Knuckle arms (El) and (8) supporting the are connected, and as is known, the front wheels (7) and (7) are steered in the steering direction of the steering wheel (1).

The pinion shaft (
8) is connected to a long linkage shaft (
10) are connected, and a universal joint (10) is connected to the rear end of the shaft (lO).
1), an input shaft (20) of a rear wheel steering system is connected thereto. As shown in FIG. 1, a flange (21) is formed at the rear end of this input shaft (20), and an extremely short eccentric shaft (22) is provided protruding from this flange (21).

On the other hand, as shown in Fig. 4, the tie rods (15) and (15) connected to the knuckle arms ([1) and (1, 8) that support the rear wheels (1?) and (17) are respectively connected to ball joints ( 13),
It is connected and supported to both ends of the joint shaft (30) via (13). As shown in FIG. 1, an engaged member (31) is fixedly provided at the center of the joint shaft (30).

That is, the engaged member (31) is connected to the cylindrical portion (32) by two bolts (39) from the rear, the joint shaft (
Acid tapered surfaces (34), (34) facing forward are fixed and integrated in the center of the joint shaft (30), and the two left and right vertical walls (33), (33) protrude forward of the joint shaft (3o). - and a pole (23) on said eccentric shaft (22)
)..., the engaging member (20) is installed, and the eccentric shaft (
22) is equipped with a contact type angular bearing. The left and right vertical walls (25) of this engaging member (24),
Male tapered surface (2B) facing rearward on the side of (25), (
2B) is formed. This double-sided tapered surface (2B), (
There is a stopper protrusion (2?) on the lower end of 2B),
Protrude (2?), (27), and (27).

Furthermore, the engagement member (20) and the engaged member (31) are sometimes assembled by using both the left and right tapered surfaces (2111),
As shown in Fig. 2 between (34), (2B), and (34), there are rollers (36) whose axes are horizontal, which are held by retainers (35) and (35), (3B). ... respectively.

The above input shaft (20) and joint shaft (30) are connected to a box (41) at the center and pipes (42) at the front and left and right sides.
) , (43) , (43) are integrally formed with the holder (
40). That is, the box of the holder (40) (
41) With the engaged member (31) facing inside, insert the joint shaft (30) into the left and right pipes (43), and the metal bearings (40° (44) so that it can slide horizontally to the left and right). Then, with the eccentric shaft (22) facing inside the box (41), the engaging member (20) is connected to the engaged member (31) and the rollers (38)..., (3B)... engage through,
The input shaft (20) is rotatably supported in the front pipe (42).

Specifically, the input shaft (20) is supported by installing a ring (28) on the front part of the flange (21) at the rear end with a pole (28) interposed therebetween, and using a contact type angular bearing. The ring (28) is lightly fitted to the inner periphery of the base end of the pipe (42). Then, place the thrust washer (51) on the front surface of the ring (29), screw and insert the sleeve (50) into the pipe (42), and then insert the sleeve (50) into the pipe (42).
Abut the rear end against the washer (51). Sleeve (50
) and the input shaft (20), a coil spring (52) is placed in this space, and the seat (53) is regulated by a step (54) at the middle of the inner circumference of the sleeve (50).
A spring (52) is compressed between the ring (51) and the washer (51) to preload the ring (51) to bias it rearward. In addition, the sleeve (50) - Rock Nara) (55
).

Also, is there a low wire between the front end of the sleeve (50) and the input shaft (20)? A rubber bearing (5B) is inserted, and a seal cap (57
) to be crowned.

In this way, the opening of the box (41) is closed with the cover (45), the input shaft (20) is aligned with the left and right center line of the vehicle body, and the left and right pipes (43) are connected to the soft mounting rubber (4B). , (4B) are interposed and supported by the vehicle body side brackets (47), (47). In addition, the left and right ball joints (1
3).

(13) is covered with compact rubber boots (48) and (4B) fastened with bands to the ends of the pipe (43) and the tie rod (15), respectively.

In order to set up the steering system, the eccentric shaft (22) is connected to the input shaft (
20), if the initial setting is vertically downward, for example, as shown in Figure 2, and the front wheels (7), (7) are steered to the right, the eccentric shaft (22) will rotate clockwise in Figure 2. Set the crank to rotate.

Therefore, when the crank rotates from the initial position of the eccentric shaft (22), the rotation angle of less than 180° is the rear wheel (17).

(17) is steered in the same direction as the front wheels (7), (7), in this case the rear wheel steering angle of 90@ is maximum, and further 180
When the angle exceeds 270°, the rear wheels are steered in the opposite direction, and the rear wheels are steered at a maximum angle of 270°. ) have the same maximum steering angle.

And join with the eccentric shaft (22)!・Sliding engagement with the shaft (30) at the tapered engagement portion (37), that is, the eccentric shaft (22)
A male taper member (24) is inserted with a pole (23)...
), and the joint shaft (30) is equipped with left and right acid taper members (33), (33) integrated, and both male and female tapered surfaces (2fl), (34), (28), (34) Since the rollers (3B)..., (3B)... are interposed between them, friction can be minimized to an extremely low level, and automatic centering can be performed by the centripetal action of the tapered engagement.

Moreover, the joint member that connects and supports the rear wheel tie rods (15), (15) is a joint shaft (30) that does not swing vertically, that is, horizontally moves only in the left and right direction,
Since the ball joints (13) and (13) are prevented from swinging up and down, errors in left and right steering angle changes can be prevented, and errors in setting the rear wheel steering angle can also be prevented, making performance confirmation easy. be able to.

Further, such a rear wheel steering system does not require a link mechanism and the eccentric shaft (22) can be made as short as possible, so the device can be made compact and the left and right shapes can be symmetrical.

Furthermore, you can select joint shafts (30) with different lengths according to the suspension type, and ball joints (13).

There are no restrictions on the arrangement of (13).

In addition, the left and right pipes (43) of the holder (40), (
Since the 43) part has a wide span to support the vehicle body, high rigidity can be obtained even when using soft mount rubber (4θ) and (4B), which is also advantageous in blocking sound and vibration. Become.

] - The sleeve (50) is inserted into the front pipe (42) of the holder (40) so that it can be adjusted forward and backward, and the sleeve (50) connects the washer (51) and the angular pole bearings (28) and (29). Input shaft (20)
The position of the locking lever (55) is made adjustable, and the engagement relationship can be adjusted. That is, the input shaft (20) is connected to the joint member (3
By moving the tapered engaging portion (37) backward to the o) side, the initial setting of the engagement state of the tapered engaging portion (37) can be properly performed without clearance while checking the performance. Therefore, the occurrence of hitting sounds can be prevented in advance 11-
can.

Furthermore, since the assembly and adjustment can be performed in this manner, there is no need for the accuracy control and inspection of each part to be very high.

Furthermore, since the preload spring (52) presses the input shaft (20) backward through the washer (51) and the angular pole bearings (2B) and (29), play in the tapered engagement portion (37) is constantly prevented. This can be prevented, and the state of retention can be maintained well even during long-term use.

That is, due to the pressing force of the spring (52), the angular ball bearings (28), (28), (23), (2
4) Since the clearance of the tapered engaging portion (37) can be maintained at zero in both the radial and thrust directions, it is possible to prevent rattling between each component and to guarantee the set steering angle.

Next, another embodiment of the adjustment and preload structure will be described with reference to FIG.

A pipe (142) that pivotally supports the input shaft (20) is formed long in the front, and a roller bearing (15B) is interposed between the rear part of the input shaft (20) and the pipe (142).
Previous□2. E% (142) 11□11□,. □□Yu
□Complete.

That is, the front part of the input shaft (20) is formed into a small diameter part (121), and the angular ball bearing (
Press-fit the inner ring (120) of the outer ring (123) and the outer ring (125).
into the large diameter portion (149) at the front of the pipe (142). Then, apply the thrust washer (151) to the front surface of the outer ring (125), screw and insert the sleeve (150) into the large diameter part of the pipe (1413), and then
Place the rear end against the washer (151). Sleeve (1
A coil spring (152) is inserted into the space between the sleeve (150) and the input shaft (20), and the spring (152) is compressed between the flange (150) provided on the inner periphery of the front part of the sleeve (150) and the washer (151). .Furthermore, screw the lock nut (155) onto the sleeve (150). In the figure (158
) is a seal ring.

Such adjustment means and preload means are also included in the present invention.

(Effects of the Invention) As described above, according to the front and rear wheel steering device of the first invention, in particular, the eccentric shaft and the joint member that moves horizontally in the left and right direction are slidably engaged by the tapered engagement portion, By providing an adjustment means to adjust the longitudinal position of the input shaft, it is possible to make the device more compact, eliminate errors in the rear wheel steering angle, and apply it to a variety of suspensions, as well as automatically align the eccentric shaft and joint member. This allows the steering angle to be maintained with high precision, and allows the use of soft mount rubber, which is advantageous in blocking noise and vibration, and also allows for assembly adjustment between the input shaft and joint member. , it is possible to achieve appropriate initial setting of the tapered engagement portion, and is highly practical.

Furthermore, in the second invention, since a preload means for biasing the input shaft toward the joint member is provided, the taper engagement portion can always be adjusted properly, preventing play from occurring due to long-term use and guaranteeing the set steering angle. be able to.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the steering angle function generation mechanism of the rear wheel steering system showing the main part of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a cross-sectional view of the adjustment and preload structure. FIG. 4 is a cross-sectional view of main parts showing another embodiment, and FIG. 4 is a schematic perspective view of the entire steering device. In the drawing, (1) is the handle, (15) is the tie rod for the rear wheel, (20) is the input shaft, (22) is the eccentric shaft, (23)
is the pole, (24) is the male tapered member, (26) is the male tapered surface, (2B), (29) and (123) are the angular bearings, (28) and (125) are the outer ring, (30)
is a joint member, (33) is an acid taper member, (34)
is the acid tapered surface, (36) is the roller, (37) is the tapered engagement part, (42) and (142) are the bearing holder, (50) and (150) are the sleeves, (51) and (+51) are the thrust Washers (52) and (152) are coil springs.

Claims (4)

[Claims] (1) The eccentric shaft installed at the rear end of the input shaft of the rear wheel steering system that rotates in conjunction with the steering wheel connects and supports the left and right rear wheel tie rods, and is supported on the vehicle body so that it can be horizontally moved in the left and right direction. In a vehicle steering system, the engagement portion between the eccentric shaft and the joint member is slidably engaged with the joint member so that both the front wheels and the rear wheels are steered by steering operation of the steering wheel. The input shaft is located on the left and right sides with respect to the shaft, is formed in a vertical direction, and is configured as a tapered engagement portion where the distance between the left and right is larger at the front part than at the rear part, and is provided with adjustment means for adjusting the position of the input shaft in the front and back direction. A front and rear wheel steering device characterized by: (2) In claim 1, the adjusting means includes an angular bearing interposed between the input shaft and its bearing holder, and a sleeve screwed into the bearing holder so that it can move forward and backward. A front and rear wheel steering device comprising a sleeve and a thrust washer interposed between the outer ring of the bearing. (3) The eccentric shaft installed at the rear end of the input shaft of the rear wheel steering system that rotates in conjunction with the steering wheel connects and supports the tie rods for the left and right rear wheels, and is supported on the vehicle body so that it can move horizontally in the left and right direction. In a vehicle steering system, the engagement portion between the eccentric shaft and the joint member is slidably engaged with the joint member so that both the front wheels and the rear wheels are steered by steering operation of the steering wheel. The input shaft is located on the left and right sides with respect to the shaft, is formed in a vertical direction, and is configured as a tapered engagement portion where the distance between the left and right is larger at the front part than at the rear part, and is provided with adjustment means for adjusting the position of the input shaft in the front and back direction. A steering device for front and rear wheels, further comprising a preload means for biasing the input shaft toward the joint member. (4) In claim 3, the adjustment means includes an angular bearing interposed between the input shaft and its bearing holder, and a sleeve screwed into the bearing holder so that it can move forward and backward. A steering device for front and rear wheels comprising a sleeve and a thrust washer interposed between an outer ring of the bearing, and the preload means is a coil spring compressed within the sleeve to press the washer rearward.