JPH0537898Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a rack and pinion type steering device for an automobile, which allows a good operating feeling to be obtained from the steering wheel of the automobile.

(Prior Art) There is a conventional rack and pinion type steering device for an automobile as shown in FIG. To explain this with a diagram, 1 is the vehicle body, and arrow Fr indicates the front thereof. Further, 2 is a steering handle, and 3 is a rack and pinion means. The rack and pinion means 3 has a gearbox 4 supported on the vehicle body 1. A through hole 5 extending substantially in the vehicle width direction is formed in the gear box 4, and a rack gear 7 is slidably fitted into the through hole 5. Also,
A rack pinion 8 that meshes with the rack gear 7 is supported on the gear box 4, and the rack pinion 8 is operatively connected to the handle 2. When the handle 2 is turned to rotate the rack pinion 8, the rack gear 7 slides within the through hole 5. Further, as the rack gear 7 slides, a left end portion 7a, which is one end side, of the rack gear 7 protrudes from the gear box 4 so as to be freely retractable.

On the other hand, the vehicle body 1 has a pivot shaft 9 whose axis is vertically oriented.
The center arm 10 is pivotally supported so as to be rotatable left and right. The rear rotary ends of the center arm 10 are interlocked and connected by tie rods 12 to knuckle arms 13 of each of the left and right front wheels, which are steering wheels. On the other hand, the front rotating end of the center arm 10 is interlocked with the protruding end 7c of the left end 7a of the rack gear 7 via an interlocking shaft 14 and a pivot 16. 15 is the steering center of the front wheels.

In the state shown by the solid line in the figure, the steering angle is 0, and the vehicle moves straight.

If you want to steer to the right from the above state, turn the handlebar 2 to the right and turn the rack pinion 8.
(arrow A in the figure). As a result, the rack gear 7 moves to the right, and the left end 7a of the rack gear 7 retreats into the gear box 4 (arrow B in the figure). This movement of the rack gear 7 causes the rear rotation end of the center arm 10 to rotate to the left (arrow C in the figure), and the accompanying rotation of the knuckle arm 13 around the steering center 15 changes the steering state to the right. obtained (indicated by a chain line in the figure).

When the steering wheel is to be steered to the left, the handlebar 2 is turned to the left to rotate the rack pinion 8 (arrow D in the figure). As a result, the rack gear 7 moves to the left, and the left end 7a of the rack gear 7 advances from the gear box 4 (arrow E in the figure). This movement of the rack gear 7 causes the rear rotation end of the center arm 10 to rotate to the right (arrow F in the figure), and the corresponding rotation of the knuckle arm 13 around the steering center 15 results in a leftward steering state. is obtained (indicated by a chain double-dashed line in the figure).

Further, in the above configuration, a pair of left and right stoppers 17 and 18 are provided protruding from the vehicle body 1 to abut against the rear rotational end of the center arm 10 and prevent the center arm 10 from rotating laterally or more than a predetermined amount. Then, the center arm 10 is connected to these left and right stoppers 1.
7 and 18, the maximum left and right steering angle is determined, that is, further left and right turning of the handlebar 2 is restricted.

(Problems to be Solved by the Invention) However, the above configuration has the following disadvantages. This will be explained in conjunction with FIG. That is, when the handle 2 is turned to the right as described above, the left end portion 7a of the rack gear 7, which is the connecting portion with the interlocking shaft 14, retreats into the gear box 4, and most of it fits into the gear box 4. It's crowded. Therefore, the rigidity of the left end portion 7a of the rack gear 7 is ensured by the gear box 4. Therefore, when the center arm 10 rotates and comes into contact with the left stopper 17, when the handle 2 is further turned to the right, the operating torque for turning the handle 2 is as shown by the arrow G in FIG. As shown in , it increases at a somewhat steep angle. In this case, the reason why the operating torque is not made infinite at the moment the center arm 10 contacts the left stopper 17 is that after the center arm 10 contacts the left stopper 17, the steering wheel 2 is not turned further. This is because it is preferable for the operating feeling of the handle 2 to be allowed to some extent and to gradually increase the operating torque of the handle 2 at this time.

On the other hand, when the handle 2 is turned to the left, the left end 7a of the rack gear 7 advances from the gear box 4 and largely protrudes from the gear box 4. The rigidity of the left end portion 7a of the rack gear 7 is reduced by the amount that this protrudes. Therefore, when the handle 2 is further turned to the left after the center arm 10 rotates and comes into contact with the right stopper 18, the left end 7a of the rack gear 7 moves toward the gear box 4 while causing the left end 7a itself to bend. The company will expand from there. Therefore, the operating torque of the handle 2 increases gradually as shown by arrow H in FIG.

In other words, in the above conventional configuration, the changes in the operating torques of the handle 2 do not match each other when the maximum steering angle is reached when the handle 2 turns to the right and when the maximum steering angle is reached when the handle 2 turns to the left. Become. This makes the driver's operating sensation unbalanced on the left and right sides when the steering wheel 2 is turned to the right and to the left, which is not preferable in terms of steering operation.

(Purpose of the invention) This invention was made with attention to the above-mentioned circumstances. When the steering wheel reaches its maximum steering angle when turning to the right and further turning of the steering wheel is restricted. and when the steering wheel reaches its maximum steering angle when turning to the left and further turning of the steering wheel is restricted, the changes in each operating torque of the steering wheel are made to almost match each other, thereby providing good operation for the driver when steering. The purpose is to provide a sense of sensation.

(Structure of the invention) The feature of this invention for achieving the above object is that when the center arm rotates as one end of the rack gear advances from the gearbox and comes into contact with the stopper, the center arm that rotates as one end of the rack gear advances from the gearbox, The present invention is characterized in that an advancement restricting means is provided for restricting the one end side of the rack gear from attempting to advance.

(Example) An example of this invention will be described below with reference to FIG. It should be noted that this embodiment is almost the same in structure and operation as the conventional example described above, and therefore different parts will be mainly explained, and common parts will be designated by reference numerals in the drawings and their explanation will be omitted.

The right end portion 7b, which is the other end side of the rack gear 7, also protrudes from the right end of the gear box 4. Attached to the right end 7b of the rack gear 7 is a stop ring 20, which is an advancement restricting means for restricting the left end 7a of the rack gear 7 from advancing beyond a certain level from the gear box 4.

The stopper ring 20 functions as follows. That is, when the handle 2 is turned to the left, the left end 7a of the rack gear 7 advances from the gear box 4 as described above. As the left end 7a of the rack gear 7 advances, the center arm 10 rotates, and when it comes into contact with the right stopper 18, the center arm 10 is prevented from rotating. When the center arm 10 contacts the right stopper 18 as described above, there is a slight gap δ between the right end surface of the gearbox 4 and the stopper ring 20. Then, when the handle 2 is further turned to the left, the left end 7a of the rack gear 7 is
It advances from the gearbox 4 while causing a deflection in itself, and the operating torque of the handle 2 begins to increase. At this time, the stopper ring 20
comes into contact with the right end surface of the gearbox 4, and prevents the left end 7a of the rack gear 7 from advancing further from the gearbox 4. Then, the operating torque of the handle 2 increases at a rather steep angle as shown by arrow I in FIG. The change in operating torque at this time substantially matches that shown by arrow G in FIG. 3 when the handle 2 is turned to the right.

(Effects of the invention) The effects of this invention are as follows. That is,
After the center arm contacts the stopper, that is, after reaching the maximum steering angle, when the handle is further turned in a direction to advance the rack gear from the gear box, the protruding end on one end of the rack gear is moved by the center arm. However, the rack gear tries to advance while causing a deflection in the part protruding from the gear box, and the operating torque of the handle tends to increase gradually. but,
In this invention, when the center arm rotates as the rack gear advances from the gearbox and comes into contact with the stopper, an advance restriction means is provided to prevent the rack gear from advancing further from the gearbox. The handle applies an external force to the rack gear whose advancement is restricted by the means. Therefore, after the rotation of the center arm is prevented by the stopper, the operating torque of the handle increases at a somewhat steep slope.

On the other hand, when the steering wheel is turned in a direction in which the rack gear retreats into the gearbox, and the center arm is prevented from rotating by the stopper, that is, when the maximum steering angle is reached, the rack gear will move backward into the gearbox. Since the rack gear is located inside, the gear box prevents it from bending even if an external force is applied to the rack gear by the handle. Therefore,
Even in this case, after the rotation of the center arm is blocked by the stopper, the operating torque of the handle increases with a steep slope to some extent.

From the above, the changes in the operating torques of the steering wheel when the steering wheel reaches the maximum steering angle when turning to the right and when the steering wheel reaches the maximum steering angle when turning to the left are almost the same. Therefore, the driver can obtain a good operational feeling when steering the vehicle.

[Brief explanation of the drawing]

Figure 1 is a plan view showing an embodiment of this invention, Figure 2 is a plan view showing an embodiment of this invention.
The figure is a plan view showing a conventional example, and FIG. 3 is a graph diagram corresponding to this invention and the conventional example, respectively. 2...Handle, 4...Gearbox, 7...
Rack gear, 7a...left end (one end side), 7c...
...Protruding end, 10... Center arm, 17... Left stopper, 18... Right stopper, 20... Stop spring (advance regulating means).

Claims (1)

[Scope of utility model registration request] A rack gear is provided with one end protruding from the gear box in conjunction with the steering handle, and a center arm is provided on the vehicle body side so as to be rotatable from side to side. The center arm is interlocked with the steering wheel, and the other rotating end of the center arm is interlocked with the protruding end of the one end of the rack gear, and the center arm is in contact with the rotating end of the center arm. In a rack and pinion type steering device for an automobile, which is provided with a stopper that prevents the arm from turning left and right beyond a predetermined value,
When the center arm that rotates as the one end side of the rack gear advances from the gear box comes into contact with the stopper, an advancement regulating means is provided for restricting the one end side of the rack gear from further advancing from the gear box. A rack and pinion type steering device for an automobile, which is characterized by: