JPS60131364A - Rack pinion steering device - Google Patents

Abstract

PURPOSE:To achieve a non-linear steering angle ratio through simple structure, by moving a gear case along the axis of rack shaft while interlocking with handle operation within setting rotary angle range of steering handle. CONSTITUTION:Upon rotary operation of handle 1 in direction A, the rack shaft 16 will move axially by the distance B'. Consequently, the groove in the rack shaft 16 will also move to displace the pin 13 of lever 13 in perpendicular direction through inclined section 17', thus to rotate the lever 12 around the pivot point 14' and to move the shaft 11 in same direction with the rack shaft 16. As a result, the gear case 4 secured to the shaft 11 will also move in same direction thus to reduce the steering angle ratio. Upon further rotation of handle 1 in the direction A, the rack shaft 16 will further move in the direction B' thus to bring the pin 13 from the inclined section 17' to the axial groove section 17'''. At this position of pin 13, the lever 12 will never rotate furthermore nor the gear case 4 will move resulting in increase of steering angle ratio.

Description

[Detailed description of the invention] The present invention is a rack and pinion type steering system U.

It is related to.

As a steering device for an automobile, a gear case is equipped with a rack shaft having rack teeth so as to be slidable in the axial direction, and a binion that engages with the rack teeth of the rack shaft is rotatably mounted on the gear case. is fixed to the vehicle body side member, and when the steering handle is rotated, the above-mentioned binion is rotated and the rack shaft is slid in the axial direction, and this t~ motion is transmitted to the wheels via the tie rod and knuckle arm to perform steering. Such a so-called rack and pinion steering device is generally widely used (see, for example, Japanese Utility Model Application Publication No. 55-37721).

Although the rack and pinion type steering equipment as described above has a simple structure, high rigidity, and is excellent in practical use, it has the disadvantage that it is extremely difficult to provide a nonlinear angle ratio.

In general, the larger the steering angle ratio (steering handle rotation angle/steering A/actual wheel steering angle), the lighter the steering force will be, but based on the principle that work amount x displacement = constant, the larger the steering angle ratio, the more the steering force will be reduced. The problem is that the angle of rotation of the steering wheel to obtain the radius increases, and the steering becomes very busy when driving on narrow roads or when driving in a garage or pulling over, etc., which requires delicate steering operations. B: Not only does the β-coupling occur, but also the steering force is too light in the high-speed straight running state i8<, which causes the driver to feel uneasy. Therefore, when steering a large steering angle, set the steering angle ratio to be large enough so that the steering force is not too large.If the required steering force is small and the steering force is too light, the steering angle ratio should be set to a sufficiently large value so that the steering force is not too large.
In the vicinity, it is desirable to reduce the steering angle ratio and set it to m'l nonlinear angle ratio, but as mentioned above, it is extremely difficult to obtain such a nonlinear angle ratio with the conventional rack and pinion steering system. Have difficulty.

The present invention is a conventional rack and pinion steering device i.
1'! ii By adding simple tii ¥zo,
This invention is designed to easily set the nonlinear angle ratio, and the present invention will be described below with reference to tolerance embodiments.

In FIG. 1, 1 is a steering handle, 2 is a steering shaft, and the steering shaft 2 has a universal joint 3°3' and an intermediate shaft 2'.
It is connected to the pinion shaft 15 via etc. Reference numeral 4 denotes a gear case which rotatably supports the pinion l1111115 and has a rack ll1ll116 internally movable in the axial direction fυ, which has a rack 116 that meshes with the pinion teeth of the pinion shaft 15.
8 so as to be movable in the same direction as the sliding direction of the rack shaft 16. The bearing 18 is attached to the vehicle body (ljl
One part is fixed on Io.

Both ends of the rack shaft 160 are connected to left and right tie rods 5, 5, and knuckle arms 7.7 are connected to the forward ends of the tie rods 5, 5, respectively. By rotating the tie rod 150 times, the rack 116 moves in the 11 direction, and the tie rod 5. The fact that steering is performed by rotating the wheels 8 via the knuckle arms 7 is similar to the conventional rack and pinion type steering device.

6 indicates a dustproof cover, and 9 indicates a suspension member.

Reference numeral 12 denotes a lever having a substantially L-shape.
The tip of one arm of the lever 12 is rotatably connected to the side 10 of the vehicle body via a link 14, and a pin 13 is fixed to the tip of the other IIEi 1 portion of the lever 12.
is provided on the rack shaft 16 supported within the gear case 4 as shown in FIG. 7Ji17 so that it can slide.

The above 1f+' (17 is the second (as shown in 1), the intermediate constant range α is 1lill ?i X of the rack shaft 16
-X It is formed in the stubborn @ groove part 17' which is inclined with respect to K, and its 1Tiii (lj:i) is formed.

b'fi-[f7)i7[rack i+h is (1)
nIh binding X -X [3F row axial grooves 11'', 17
The pin 13 is formed at approximately the center of the inclined groove portion 17' as shown in FIG. .

As shown in FIG. 1, the gear case 4 is provided with a slot 4' through which the pin 13 passes with a margin.

In the above setup, for example, when the steering handle 1 is rotated in the direction of arrow A, the pinion ffn1t15 is rotated in the same direction, and the rack shaft 16 is moved by 13' in the axial direction, as shown in FIG. The groove 17 moves from the solid line position to the dotted line position r, and the pin 13 moves from the solid line position to the dotted line position following the shape of the inclined groove part 17', along the axis X of the rack shaft.
-The lever 12 is displaced by an amount B'' in a direction substantially perpendicular to X, so that the lever 12 moves clockwise (B) in the figure with the shaft 11 as the center, as shown in FIG.

Since the pivot point 14' of the lever 12 to the vehicle body side member 10 (lIil) is fixed in the x-xH force direction, the rotation of the lever 12 causes the shaft 11 to move from the fourth recess (a) to C=
B" The gear case 4 is forcibly moved to the left in the figure by the amount of movement C.

Therefore, the movement B of the tie rod 5 is the sum of the movement B' of the rack shaft 16 relative to the gear case 4 and the movement C of the gear case 4 itself, that is, Ll = B' + C, and the actual steering angle is the gear of the rack and pinion itself. The steering angle ratio increases by the amount B' due to the ratio, that is, the steering angle ratio becomes small by 7'A:.

When the steering handle 1 is further turned b (υ) in the direction B and the rack shaft 16 is further moved in the B' direction and the bin 13 reaches the axial groove 1γ from the inclined groove 11', the axis of the pin 13 is Since there is no displacement in the direction intersecting the direction 11 and the lever 12 does not rotate any further, the shaft 11 and gear case 4 do not move 1i1J, and therefore the pin 13 is 116t+
After reaching direction +71\part 17, the actual steering angle is determined only by the gear ratio of the binion and rack, the steering angle ratio becomes large, and the 111e force at the time of large steering can be reduced.

The relationship between the steering wheel rotation angle and the actual steering angle of the wheels is shown in a graph as shown in FIG.

That is, the actual steering angle characteristic according to the present invention is a nonlinear characteristic 1, which is the sum of the movement H of the rack shaft relative to the gear case due to the gear ratio of the rack and the pinion, and the movement H of the gear case itself, and the movement of the gear case itself in the steering direction. In the range α of the inclined groove portion 17', the steering angle ratio is small, the movement of the rudder is good, and the steering force is not too light, so there is no feeling of anxiety when driving straight at high speed, and the gear case itself does not move, that is, the axial groove portion In the ranges b and b' of 17' and 1γ'', the steering angle ratio is large and the steering force during large steering turns can be increased. can be reduced.

Incidentally, the nonlinear characteristic of the steering angle ratio obtained by the present invention is determined by the range α of the inclined groove portion 17′ and the inclined groove portion 17′.
The inclination angle history with respect to the X-X line can be arbitrarily selected by changing the arm length ratio ' 2 /l + of the lever 12.

In the above embodiment, an example is shown in which the lever 12 and the rack shaft are provided to reduce the steering angle ratio.
The means for moving the gear case itself in the present invention is not limited to the above-mentioned embodiments; for example, the steering wheel, the steering shaft that rotates together with it, the rotation angle of the binion 'f (!l %), or the gear case on the rack shaft. Detect the amount of axial movement 'MJ' for 'electricity 1J'J
An inn that is provided with a steering angle sensor that emits a signal and an electric actuator that controls the movement of the gear case based on the signal from the steering angle sensor, and any gear case movement control means may be adopted within the city limits of the object of the present invention. I can do it.

As mentioned above, in Honzu 4 Akira, rack and pinion 2~
The gear case itself of the steering device 171- is attached to the vehicle body side member so as to be movable along the line 1iIllI of the rack axis, and a gear case movement control means is provided to move the gear case itself within the set rotation angle range of the steering handle. Therefore, the nonlinear steering Sa
Easy to install rack and pinion type steering equipment. There is something that can be obtained in one day and can have a great practical effect.

[Brief explanation of the drawing]

1 is an explanatory plan view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, and FIG. 6 is an explanation showing the displacement mode of the pin when the rack axis moves as shown in FIG. 2. Figures 4(a) and 4(b) are explanatory diagrams showing the rotational behavior of the lever due to the displacement of the bottle in Figure 6, respectively, and Figure 5 is a diagram showing the steering angle ratio characteristics in the present invention. 1... Steering handle, 4... Gear case,
5... Tie rod, 1... Knuckle arm, 8...
・Car 44.12...Lever, 13...Bin, 15.
...Binion shaft, 16...Rack shaft, 17 ・-fi
4゜ or more Upper Sai 1 Flash 412] Figure Ya 5

Claims (1)

[Claims] A binion that rotates as the steering wheel is rotated is installed in the gear case so that it can be rotated, and a rack shaft that fits one candy is mounted on the binion so that it can be moved in the axial direction. In the rack and pinion type steering device, the gear case is mounted on a vehicle body side member so as to be movable in the axial direction of the rack shaft. 1. A rack and pinion type steering device, characterized in that a gear case movement control means is provided for moving the gear case in accordance with a rotational operation in a setting rotation angle range of the steering wheel.