JPH047029Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a rack-and-pinion steering device for automobiles, and more specifically, a rack-and-pinion steering device with a steering linkage that increases steering force on the principle of leverage. Regarding equipment.

(Prior Art) As a conventional rack-and-pinion type steering device, for example, one described in Japanese Utility Model Application Publication No. 58-3369 is known. This rack-and-pinion steering device has a pinion and a rack with teeth that move together in the axial direction, and supports the pinion so that it can move in the axial direction, thereby preventing vibrations generated in the wheels from being transmitted to the steering handle. be.

As is well known, in such a rack-and-pinion type steering device, each end of the rack is connected to the left and right steering wheels via steering linkages such as left and right tie rods, and the rotation of the steering wheel and the steering force are controlled. Transmitted to the direction wheels.

(Problem to be solved by this invention) However, in such conventional rack-and-pinion steering devices, the overall ratio (steering The problem was that the steering wheel was heavy because the gear ratio could not be increased. In other words, to increase the overall ratio, increase the length of the steering wheel's knuckle arm to increase the moment due to the linear motion of the tie rod, or decrease the diameter of the pinion (reduce the number of teeth). One possibility is to increase the easy stroke relative to the rotation angle of the pinion, but increasing the length of the knuckle arm requires increasing the size of the road wheel, and decreasing the diameter of the pinion reduces the strength of the pinion. Therefore, it was practically impossible to increase the overall ratio.

Furthermore, with such conventional rack-and-pinion steering devices, the left and right tie rods are arranged approximately in a straight line with the rack, increasing the size in the vehicle width direction, which reduces the degree of freedom in linkage arrangement. However, there was a problem in that it was difficult to set the wheel alignment so that changes in the toe angle of the steering wheels, etc. had desired characteristics.

(Means for solving the problems) This invention was made with the aim of solving each of the problems mentioned above. A rack and pinion type steering device comprising a rack connected to each of the steering wheels via a steering linkage, wherein the steering linkage is arranged on both left and right sides of the rack and extends substantially in the longitudinal direction of the vehicle,
a pair of relay levers having one end connected to the rack via a joint and the other end rotatably supported by the vehicle body; and a pair of relay levers having respective ends connected to the pair of relay levers via a joint; a relay rod bridged between the levers substantially parallel to the rack, one end of which is connected to the relay rod through a ball joint, and the other end connected to the knuckle arm of the left steering wheel through a ball joint; and a right tie rod having one end connected to the relay rod through a ball joint and the other end connected to the knuckle arm of the right steering wheel through a ball joint.

(Function) According to the rack-and-pinion steering device according to this invention, as the steering wheel is steered, the pinion rotates and the rack meshed with the pinion is displaced, and the displacement of the rack causes each relay lever to move toward the vehicle body. The relay rod is moved approximately parallel to the rack by swinging around the support point. At this time,
The displacement of the rack is determined by each relay lever depending on the ratio of the length from the point of support of the relay lever to the vehicle body to the point of connection to the rack and the length from the point of support to the vehicle body to the point of connection to the relay rod. It is transmitted in a reduced form. That is, according to this principle, the displacement of the rack is reduced by the swinging of the relay lever and transmitted to the relay rod, and the displacement of the relay rod is transmitted to the left and right steering wheels via the left and right tie rods. Therefore, the overall ratio increases, and the steering force applied to the steering wheel is increased and transmitted to the steering wheels, thereby reducing the steering burden on the driver.

In addition, with this steering device, the steering efficiency can be changed by adjusting the angle at which the relay lever is attached to the vehicle body, in other words, the angle formed between the relay lever and the rack or relay rod.
There is a large degree of freedom in setting its characteristics.

Furthermore, with this steering device, the tie rod can be connected to the relay rod at a position shifted toward the center of the vehicle body, so it can be made smaller in the vehicle width direction, giving greater flexibility in linkage arrangement even in small vehicles. becomes larger, allowing you to set the desired wheel alignment.

(Example) Hereinafter, an example of this invention will be described based on the drawings.

The drawing shows an embodiment of the rack-and-pinion steering device according to the invention.

First, to explain the structure, numeral 11 is a gear housing in which a rack-and-pinion type steering gear mechanism is housed, and the gear housing 11 is supported by a vehicle body 12 by a mounting device (not shown). As is well known, the steering gear mechanism includes a pinion (not shown) that is connected to a steering handle (not shown) via a steering shaft or the like and rotates together with the steering handle, and a pinion (not shown) that is connected to the steering handle (not shown) through a steering shaft or the like and rotates in the approximate width direction of the vehicle. It has an extending rack 13 whose left and right ends protrude from the gear housing 11. When the pinion rotates as the steering wheel is turned, the rack 13 moves in the axial direction (vehicle width direction).
Displaced to.

Auxiliary rods 14 are connected to the left and right ends of the rack 13 through joints 15L and 15R, respectively.
One end of each of L and 14R is connected. These auxiliary rods 14L, 14R extend substantially in a straight line with the rack 13, and each other end is connected to the joint 1.
The relay levers 6L and 16R are connected to the front end portions of relay levers 17L and 17R extending substantially in the longitudinal direction of the vehicle on both sides of the rack 13. These relay levers 17
The rear ends of L and 17R are respectively attached to the vehicle body 12 via joints 18L and 18R,
Further, the ends of a relay rod 19 extending substantially parallel to the rack 13 are connected to each other at predetermined positions between the ends via ball joints 25L and 25R. These relay levers 17L, 17R form a predetermined angle with respect to the longitudinal direction of the vehicle. Relay rod 1 from 18R
The displacement of the rack 13 is reduced in accordance with the ratio (1/L) of the distance 1 to the joints 25L and 25R at both ends of the rack 9 and transmitted to the relay rod 19. here,
The rack 13, the auxiliary rods 14L, 14R, the relay rod 19, and the relay levers 17L, 17R are arranged to move on the same plane and cannot substantially move up and down. relay rod 19
have two tie rods on the left and right between their ends.
One end of 0L and 20R is a ball joint 21
It is bonded via L and 21R. The other end of the left tie rod 20L is connected to the knuckle arm 22L of the left steering wheel 30L via a ball joint 23L, and similarly, the other end of the right tie rod 20R is connected to the knuckle arm 22R of the right steering wheel 30R via a ball joint 23L. They are connected via a joint 23R. The aforementioned auxiliary rods 14L, 14R, relay levers 17L, 17R, relay rod 19 and tie rods 20L, 20R are part of the steering linkage 2.
4.

Next, the action will be explained.

When the driver turns the steering wheel, the pinion of the steering gear mechanism rotates, and the rack 13 meshed with the pinion moves in the axial direction. The movement or displacement of this rack 13 is controlled by relay levers 17L and 14R via auxiliary rods 14L and 14R.
17R, each relay lever 17L, 17
R rotates around joints 18L and 18R on the vehicle body 12 side to move the relay rod 19 approximately parallel to the rack 13. At this time, the displacement δ _R of the rack 13 is
As shown in the formula below, relay lever 1 is
Relay rod 19 is reduced by 7L and 17R.
transmitted to.

δ _S = 1/L・δ _R However, δ _S : Displacement of relay rod 19, δ _R : Displacement of rack 13, L: Joints 18L, 18R on the vehicle body 12 side and joints 16L, 1 on both ends of rack 13.
Distance between 6R and 1: Joints 18L and 18R on the vehicle body 12 side and joints 25 on both ends of the relay rod 19
In other words, the overall ratio is increased by the relay levers 17L and 17R in accordance with the above ratio (1/L), and the steering force applied to the steering wheel is increased and transferred to the relay rod 19. communicated. The displacement of the relay rod 19, that is, the steering force, is transmitted from the left and right tie rods 20L, 20R to the steering wheels 30L, 30R.
Rotate the 30R around the king pin to steer.

In this way, with this rack-and-pinion steering device, the overall ratio can be increased without increasing the size of the road wheel of the steering wheel or reducing the diameter of the pinion, thereby reducing the burden on the driver. can be reduced. Therefore, even in commercial vehicles that carry heavy objects and require a large steering burden, but it is difficult to install a power steering device due to manufacturing cost constraints, the manufacturing cost can be increased by installing the steering device according to this invention. It becomes possible to reduce the burden on the driver without causing any problems.

In addition, in this steering device, the angle formed between the relay levers 17L, 17R and the relay rod 19 or the rack 13, or the angle formed by the tie rod 2
By adjusting the angle formed by 0L, 20R and the relay rod 19, the efficiency of the steering which determines the Atkerman mechanism can be set to an appropriate value, so the degree of freedom in the setting is increased.

Furthermore, in this steering device, the ends of the tie rods 20L and 20R are connected to the relay lever 1.
Since it is connected to the relay rod 19 between 7L and 17R, it is possible to reduce the size in the vehicle width direction, and the degree of freedom in the arrangement position of each link is increased, making it possible to set the desired wheel alignment. become.

In addition, the auxiliary rod 14L in the above embodiment,
14R is not necessarily necessary, relay lever 17
L and 17R may be jointed to the end of the rack shaft 13. In this case, the joint etc. should have relief in the longitudinal direction of the vehicle body, and the relay lever 17L,
It is necessary to prevent the rotation of 17R from being forced.

(Effects of the invention) As explained above, according to the locked pinion type steering device according to this invention,
A pair of relay levers, one end of which is rotatably supported by the vehicle body and the other end of which is easily connected, is bridged by a relay rod with the ends of each of these relay levers rotatably connected. By connecting the other ends of the left and right tie rods, one end of which is connected to the knuckle arm of the steering wheel, it is possible to increase the overall ratio and reduce the steering burden on the driver, as well as to attach the relay lever. It is now possible to adjust the steering efficiency by setting the angle, and it is also possible to reduce the size of the vehicle in the width direction and increase the degree of freedom in setting the wheel alignment.

[Brief explanation of the drawing]

The drawing is a schematic plan view showing an embodiment of the rack-and-pinion steering device according to the invention. 11...Gear housing, 12...Vehicle body, 13
...Rack, 15L, 15R, 16L, 16R,
18L, 18R, 25L, 25R...Joint, 21L, 21R, 23L, 23R...Ball joint, 14L, 14R...Auxiliary rod, 1
7L, 17R...Relay lever, 19...Relay rod, 20L, 20R...Tie rod, 30
L, 30R...Steering wheel, 22L, 22R...Natsukuru arm, 24...Steering linkage.

Claims (1)

[Scope of utility model registration request] In a rack-and-pinion steering device comprising a pinion that rotates together with a steering handle, and a rack that meshes with the pinion and is connected to left and right steering wheels via steering linkages, the steering linkage is connected to the rack. a pair of relay levers disposed on the left and right sides and extending substantially in the longitudinal direction of the vehicle, one end of which is connected to the rack via a joint and the other end rotatably supported by the vehicle body; a relay rod whose ends are connected to the relay levers via joints, and which are bridged between the pair of relay levers in substantially parallel to the rack; and whose one end is connected to the relay rod via a ball joint and the other end is connected to the relay rod through a ball joint. a left tie rod connected to the knuckle arm of the left steering wheel via a ball joint; and a knuckle arm of the right steering wheel, one end of which is connected to the relay rod via a ball joint and the other end of the tie rod connected to the knuckle arm of the right steering wheel. A rack-and-pinion steering device characterized by having a right tie rod coupled to the right tie rod through a ball joint.