JPH0512358U - Rack and pinion type steering device - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce wear of pinion gear bearings,
In addition, interference with the suspension system is eliminated, and sufficient anti-vibration measures can be taken regarding the mounting of the steering gear box. [Structure] The steering gear boxes 4 are arranged on both sides of a pinion gear 34 so as to face each other, mesh with the pinion gears 34, and rotate on the knuckles 8 of each steering wheel 13 on both sides of a kingpin 12. It is provided with a pair of racks 45 and 46 that are movably connected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rack and pinion type steering device for an automobile or the like.

[0002]

[Prior Art]

 Conventionally, as a steering gear mechanism of a steering device of an automobile or the like, a warm sector type, a ball nut type, a rack and pinion type, etc. are known. These inner rack-and-pinion type steering devices are the mainstream of the steering gear mechanism because of their relatively simple structure and sharpness.

In this rack-and-pinion type steering device, as shown in FIG. 3, the rotational steering force applied to the steering wheel 51 is transmitted through the steering shaft 52, the connecting shaft 53 and the like to the steering gear box (steering gear). Transmission to the pinion gear 55 in the ring gear mechanism 54. Then, the rotational steering force transmitted to the pinion gear 55 is converted into reciprocating motion by the single rack 56 meshing with the pinion gear 55 and transmitted to the tie rods 57 and 57 connected to both ends of the rack 56.

The tie rods 57, 57 are rotatably connected to knuckle arms 59, 59 that are fixed to knuckles 58, 58 that pivotally support the steering wheels 63, 63 and project rearward. On the other hand, the steering gear box 54 described above is fixed to the vehicle body frame 60 via a vibration-proof rubber. Suspension arms 61, 61 are attached to the body frame 60 so as to be swingable in a substantially vertical direction. The above-described knuckles 58, 58 are pivotally supported at the tips of the suspension arms 61, 61 via king pins 62, 62. That is, a so-called link mechanism of the steering device is configured in this way.

Therefore, the reciprocating motion transmitted to the tie rods 57, 57 is transmitted to the knuckle arms 59, 59, and the knuckle arms 59, 59 are swung about the king pins 62, 62. As a result, the directions of the knuckles 58, 58 that pivotally support the steered wheels 63, 63 are changed. In the conventional rack-and-pinion type steering device, the steering wheels 63, 63 are steered in this manner.

[0006]

[Problems to be solved by the device]

 However, in the conventional rack-and-pinion type steering device, in order to ensure the meshing between the rack 56 and the pinion gear 55 described above, the back surface of the rack 56 is pushed by a spring, and the rack 56 and the pinion gear 55 are A constant preload is applied between. For this reason, the pinion gear bearing (not shown) that pivotally supports the pinion gear 55 always receives a load from one direction, causing a problem of wear.

Further, in the link mechanism of the steering device described above, it is necessary that each constituent element has high rigidity in order to enhance the steerability of the steered wheels 63, 63. That is, high rigidity must be provided between the steering gear box 54, the vehicle body frame 60, and the suspension arms 61, 61 described above, particularly in the rotating direction of the knuckles 58, 58 about the king pins 62, 62. I have to. For this reason, the so-called steering system and suspension system become congested, and they interfere with each other to complicate the characteristic settings of each, especially the suspension system, making it difficult to achieve high-performance undercarriage. There is a problem of letting.

Further, the steering gear box 54 is attached to the vehicle body frame 60 via the anti-vibration rubber as described above, but on the other hand, as described above, a high mounting rigidity is required in order to enhance the steerability. Therefore, there is a problem that the mounting rigidity is weakened and sufficient anti-vibration measures cannot be taken. The present invention has been made to solve such a problem, and reduces wear of the pinion gear bearings that pivotally support the pinion gear 55 to improve durability, and separates the suspension system and the steering system from each other. The rack-and-pinion system allows easy specific setting of the steering gear box and does not impair steerability even if the rigidity of mounting the steering gear box 54 on the vehicle body is reduced, and sufficient anti-vibration measures can be taken for the mounting. An object of the present invention is to provide a steering system.

[0009]

[Means for Solving the Problems]

 To achieve the above object, according to the present invention, in a rack and pinion type steering device in which the steering gear mechanism is a rack and pinion, the steering gear mechanism is disposed opposite to both sides of the pinion gear. , Each of which is meshed with a pinion gear, and each of which is provided with a pair of racks which are rotatably connected to a knuckle of a steering wheel on both sides of a king pin.

[0010]

[Action]

 In the rack-and-pinion type steering device described above, the steering gear mechanism is arranged on both sides of the pinion gear that transmits the rotational driving force of the steering wheel, and the pair of steering gear mechanisms mesh with the pinion gear, that is, two pairs. This pair of racks can be freely pivoted to the steering wheel knuckle on both sides of the kingpin, that is, generally in the front-back position of the kingpin, with tie rods or the like as needed. Is linked to.

That is, the pinion gear is pressed from both sides by the pair of racks substantially evenly, and is axially supported at the center of the pinion gear bearing, so that the pinion gear bearing is prevented from deviating and the load is increased. Reduce to width. Also, when rotational steering force is applied to the steering wheel, the racks move in opposite directions by the pinion gears, and the steering moment around the kingpin with respect to the knuckle of the steering wheel is applied to the body frame and suspension arm. It is generated directly without intervention.

[0012]

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a concrete structure of the rack and pinion type steering device of the present invention. Reference numeral 1 denotes a steering wheel, which is arranged in the vehicle compartment. The steering wheel 1 is fixed to a steering shaft 2 pivotally supported by a steering column (not shown), and rotates integrally with the steering shaft 2. Further, the steering shaft 2 is connected to a connecting shaft 16 via a steering joint 15. The steering joint 15 is composed of a combination of two universal joints, and rotatably connects the steering shaft 2 and the connecting shaft 16 having different mounting angles.

Next, reference numeral 10 denotes a vehicle body frame, to which a steering gear box (steering gear mechanism) 4 described in detail later is attached via a mount rubber (not shown) and brackets 14 and 14. ing. The mounting structure of the steering gear box 4 constituted by the mount rubber and the brackets 14, 14 is extremely flexible and low in rigidity as compared with the mounting structure of the conventional rack and pinion type steering device described above. Therefore, sufficient and effective anti-vibration measures are taken so that the vehicle body vibration is not transmitted from the vehicle body frame 10 to the vehicle interior via the steering gear box 4, the steering shaft 52 and the like.

The steering gear box 4 is provided with a gear box housing 21 as shown in FIG. 2, and the gear box housing 21 is composed of an upper housing 22 and a lower housing 23. The upper housing 22 has a substantially cylindrical shape, and the lower housing 23 has a shape in which approximately two cylinders are cross-shaped, that is, a shape intersecting the left-right direction in the drawing and the direction orthogonal to the paper surface, and the upper housing at the intersection. The housing 22 and the cylinders are mounted in a liquid-tight manner so as to be orthogonal to each other.

A cylindrical input shaft 20 is axially supported by the upper housing 22 via input shaft bearings 24, 25. The upper end of the input shaft 20 projects from the upper housing 22 and is integrally connected to the connecting shaft 16 described above. A liquid seal is provided between the input shaft 20 and the upper end of the upper housing 22 by a seal 26.

A control valve mechanism (not shown) of the power steering system is arranged around the input shaft 20 in the upper housing 22. Reference numerals 28 and 29 denote connection ports for connecting the control valve mechanism to a hydraulic line of a power steering system (not shown). Then, the torsion bar 27 is fitted inside the input shaft 20 and rotates together with the input shaft 20. A part of the torsion bar 27 projects from the lower end of the input shaft 20.

Next, reference numeral 30 denotes a pinion gear shaft, the upper end of which is axially supported by the upper housing 22 via a pinion gear ring 31, and the lower end of which is axially supported by the lower housing 23 via a pinion gear bearing 32. It is supported. Then, the above-mentioned protruding end of the torsion bar 27 and the pinion gear shaft 30 are spline-coupled and rotate integrally. That is, the rotational driving force input to the input shaft 20 is transmitted to the pinion gear shaft 30 via the torsion bar 27. Further, the lower end of the upper housing 22 is liquid-sealed by a seal 33 disposed directly below the pinion gear bearing 31 sealing between the pinion gear shaft 30 and the lower housing 23. A pinion gear 34 is formed on the outer peripheral surface of the lower portion of the pinion gear shaft 30.

Next, on both sides of the pinion gear 34, a pair of racks 35 and 36 are disposed so as to face each other. The cylindrical parts are fitted in each. On the other hand, guides 37, 38, pressing springs 39, 40, and plugs 41, 42 are arranged in this order on the cylindrical portion of the lower housing 23 extending in the left-right direction so as to grip the racks 35, 36 from the left and right sides, respectively. Are installed respectively. That is, the racks 35, 36 are slidably guided in the axial direction by the guides 37, 38, and the guides 37, 38 are guided by the plugs 41, 42 via the pressing springs 39, 40. , 36 side is always urged. That is, in the rack-and-pinion type steering device, the pinion gear 34, that is, the pinion gear shaft 30 is constantly pressed by the racks 35, 36 from the left and right sides with substantially equal spring force, and the pinion gear bearing 31, Since the structure is pivotally supported at the center of 32, the pinion gear bearings 31 and 32 are prevented from being offset, and the load thereof is greatly reduced. As a result, the wear of the pinion gear bearings 31, 32 is effectively reduced, and the durability is improved.

Further, both ends of each of the racks 35 and 36 described above project from the lower housing 23, and tie rods 45, 45 and 46, 46 are ball-joined and connected, respectively. Further, in the lower housing 23 into which the racks 35 and 36 are fitted and inserted, a hydraulic cylinder of a power steering system (not shown) and the like are arranged.

Next, returning to FIG. 1, suspension arms 11, 11 are attached to the left and right sides of the vehicle body frame 60 so as to be swingable in a substantially vertical direction. Knuckles 8, 8 which pivotally support the steering wheels 13, 13 via hubs (not shown) are pivotally supported by the kingpins 12, 12 at the tips of the suspension arms 11, 11, respectively. Further, short knuckle arms 43 and 44 extend from each knuckle 11 on both sides of the king pin 12, that is, in the front-rear direction, and are fixed to each other.

The knuckle arms 43, 43 and the above-mentioned tie rods 45, 45 are ball-joined respectively, and the knuckle arms 44, 44 and the above-mentioned tie rods 46, 46 are respectively ball-jointed and connected. ing. Here, it is desirable that the width between the ball joy joints of the knuckle arms 43 and 44 and the tie rods 45 and 46 be set to be as wide as possible between the racks 35 and 36.

The configuration of the rack and pinion steering device is as described above. Next, the operation of the rack and pinion type steering device will be described. First, when the driver rotates the steering wheel 1, the rotational driving force is applied to the pinion through the steering shaft 2, the steering joint 15, the connecting shaft 16, the input shaft 23 in the steering gear box 4, and the torsion bar 27. It is transmitted to the gear shaft 30.

When the pinion gear shaft 30 is rotationally driven, the racks 35 and 36 move in mutually opposite directions and linearly move. The linear motions of the racks 35 and 36 that face each other are transmitted to the left and right knuckle arms 43, 43 and 44, 44 via the tie rods 45, 45 and 46, 46, respectively. As described above, the knuckle arms 43 and 44 are fixed to both sides of the kingpin 12 by extending in the front-rear direction. Therefore, the tie rods 45 and 46 cooperate with each other to generate a rotational moment for rotating the knuckle 8 around the kingpin 12.

As a result, the left and right steering wheels 13, 13 are turned in the same direction, and steering is performed. As described above, in the present rack and pinion type steering device, the steering moment around the king pins 12, 12 with respect to the steered wheels 13, 13 is different from that in the conventional rack and pinion type steering device. , 11 etc. are not generated. Therefore, it is possible to separate the suspension system and the steering system and eliminate mutual interference. This simplifies the setting of the characteristics of each system and makes it easy to achieve high-performance suspensions, especially for suspension systems.

Further, even if the rigidity for mounting the steering gear box 4 on the vehicle body is reduced, the steerability of the steered wheels 13, 13 will not be impaired. You will be able to take measures against shaking. The rack-and-pinion type steering device of the present invention is not limited to the one embodiment described above, and various modifications can be made.

For example, in the steering gear box 4 described above, the control valve mechanism of the power steering system, the hydraulic cylinder, and the like do not necessarily have to be provided, and the specific configuration related to the rack and pinion can be appropriately changed. it can. Further, various forms are also conceivable for the method of connecting the racks 35, 36 and the knuckles 8, 8.

[0027]

[Effect of the device]

 As described in detail above, in the vehicle rack-and-pinion type steering device of the present invention, the steering gear mechanisms are arranged opposite to each other on both sides of the pinion gears, and the steering gear mechanisms are meshed with the pinion gears, respectively. Is equipped with a pair of racks rotatably connected to the knuckles of the steering wheels on both sides of the kingpin.

That is, the pinion gear is pressed substantially equally from both sides by the pair of racks to be axially supported at the center of the pinion gear bearing, and the pinion gear bearing is prevented from deviating to a large extent. The width is reduced. Therefore, the wear of the pinion gear bearing is effectively reduced, and the durability can be improved.

Further, since the steering moment around the kingpin is directly generated with respect to the steered wheels without passing through the vehicle body frame, suspension arm, etc., the suspension system and the steering system are separated from each other, and mutual interference is effective. Can be eliminated. This simplifies the setting of the characteristics of the respective systems, and facilitates achievement of high-performance undercarriage, particularly for suspension systems.

Further, as described above, since the steering moment around the kingpin is directly generated with respect to the steered wheels, the rigidity of mounting the steering gear box on the vehicle body is reduced without impairing the steerability of the steered wheels. , Sufficient anti-vibration measures can be taken on the part where the steering gear box is attached to the body frame.

[Brief description of drawings]

FIG. 1 is a simplified system diagram showing a specific configuration of a vehicle rack and pinion steering device according to the present invention.

FIG. 2 is a side sectional view showing a configuration of a main part of a steering gear box 4 in FIG.

FIG. 3 is a simplified system diagram showing a configuration of a conventional vehicle rack-and-pinion steering device.

[Explanation of Codes] 1 Steering Wheel 2 Steering Shaft 4 Steering Gear Box (Stearing Gear Mechanism) 8 Knuckle 10 Body Frame 11 Suspension Arm 12 King Pin 13 Steering Wheel 16 Connecting Shaft 20 Input Shaft 21 Gear Box Housing 27 Torsion Bar 30 Pinion Gear shaft 31, 32 Pinion gear bearing 34 Pinion gear 35, 36 Rack 43, 44 Knuckle arm 45, 46 Tie rod

Claims (1)

[Scope of utility model registration request] 1. A rack-and-pinion type steering device in which a steering gear mechanism is a rack-and-pinion type steering device, wherein the steering gear mechanism is disposed on both sides of the pinion gear so as to face each other, and each meshes with the pinion gear. A rack-and-pinion type steering device comprising a pair of racks, each of which is rotatably connected to a knuckle of a steering wheel on both sides of a kingpin.