JP2002067983A - Automatic rack and pinion meshing adjusting device for rack and pinion type steering gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic rack and pinion meshing adjusting device for a rack and pinion type front wheel steering gear capable of appropriating rotational torque of a pinion shaft and automatically adjusting so as to prevent operation from becoming heavy due to excessive heavy torque without causing gear noise. SOLUTION: A fitting tool 13 of a first control motor 11 is fitted on a damper screw 8 of a rack case 1 provided on an installation base 9. A rotational torque meter 15 of a second control motor 14 is fitted on the pinion shaft 3. The damper screw 8 is tightened by the first control motor 11 set at a strong torque. In this state, rotational torque is detected by reciprocatively rotating the pinion shaft 3 by the second control motor 14, the detected value is collated with a rotational torque curve characteristic of the pinion shaft 3, and the damper screw 8 is loosened by the first control motor just a rotational degree based upon the collation value. By this, the pinion shaft can be rotated at a proper rotational torque and it can be adjusted to prevent tooth hammering noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rack and pinion meshing automatic adjusting device for a rack and pinion type steering device of a four-wheel vehicle, for example.

[0002]

2. Description of the Related Art As shown in FIGS. 5 and 6, a rack and pinion type front wheel steering device used in a four-wheeled vehicle has a pinion shaft 3 mounted in a substantially cup-shaped rack case 1 in its axial direction. A pinion (pinion gear) 4 is formed on the outer peripheral surface of the pinion shaft 3 inside the rack case 1. A rack bar 2 is slidably inserted into the rack case 1 in a direction substantially perpendicular or at an angle to the pinion shaft 3, and a rack (rack gear) 2 a meshes with the pinion 4 of the pinion shaft 3. . Then, both ends of the rack bar 2 are connected to left and right front wheels via tie rods 5 and 5, while the pinion shaft 3 is connected to a handle shaft (not shown). Then, when the occupant rotates the driving handle shaft left and right from the vehicle interior, the pinion shaft 3 rotates.
The rotation of the pinion shaft 3 causes the rack bar 2 to slide left and right, thereby turning the left and right front wheels via the right and left tie rods 5 to steer.

Here, in the rack case 1, a cylindrical opening 1a is formed on the side opposite to the pinion shaft 3 of the rack bar 2, and a plunger is inserted into the rack bar 2 in the cylindrical opening 1a. The plunger 6 is accommodated along the inside of the semicircular cross section of the plunger 6. On the other hand, in the cylindrical opening 1a, a spring 7 is mounted from the outside of the plunger 6, and a damper screw 8 is screwed into the cylindrical opening 1a.
Is pressed against the pinion 4.

If the force of the plunger 6 pressing the rack bar 2 is too strong, the rotation operation of the pinion shaft 3 becomes heavy, which causes inconvenience in that the handle operation becomes heavy. If the gap t generated between the plunger 6 and the damper screw 8 is large, when the vibration of the wheels is transmitted to the rack bar 2 via the tie rod 5, the rack 2a of the rack bar 2 and the pinion 4 The teeth hitting sound is generated between these parts and the condition is not good. Therefore, it is necessary to tighten the gap t between the damper screw 8 and the plunger 6 so as to minimize the gap.

[0005]

Usually, in a production line of a rack and pinion type front wheel steering device, a torque wrench or the like is used
Tighten until a certain tightening is obtained, depending on experience,
The tightening of the damper screw 8 is loosened by a predetermined number of times, and the rotation torque of the pinion shaft 3 is adjusted so as not to be too heavy and not too light and to be appropriate. However, even an experienced person is apt to make the above-mentioned tightening vary slightly, so that the rotational torque of the pinion shaft 3 is set to an appropriate value, and the gap t between the plunger 6 and the damper screw 8 is set to an appropriate value. It was difficult and a heavy workload.

In view of the above, the present invention makes it possible to adjust the rotation of the pinion shaft to an appropriate torque, and to automatically adjust the clearance t so that the operation is not heavy because the clearance t is too large and no rattle is generated. An object of the present invention is to obtain a rack and pinion meshing automatic adjusting device for a rack and pinion type steering device.

[0007]

In order to achieve the above object, an automatic rack and pinion meshing adjusting device for a rack and pinion type steering device according to the present invention is provided in which a first control motor is fitted to a damper screw of a rack case of an installation base. In addition to fitting the insertion tool, the rotation torque meter of the second control motor is fitted to the pinion shaft, for example, the damper screw can be tightened with the first control motor set to a strong torque, and the pinion shaft is reciprocated by the second control motor. Rotate to detect the rotational torque with the rotational torque meter, collate the detected value with the rotational torque curve characteristics of the pinion shaft, adjust the tightening by the damper screw with the first control motor based on the collation result, and adjust the pinion shaft. It can rotate with an appropriate rotation torque and can be adjusted so as to minimize the gap t.

According to the present invention, the fitting tool of the first control motor is fitted to the damper screw of the rack case installed on the mounting table, and the damper screw is set to a value set to a tightening force higher than the appropriate tightening force. Tighten the damper screw with the first control motor. The rotation torque of the pinion shaft at this time is detected by rotating the pinion shaft with a rotation torque meter of the second control motor fitted to the pinion shaft.

[0009] The rotational torque of the pinion shaft is such that while the spring between the damper screw and the plunger pressing the rack bar is compressed, the rotational torque of the pinion shaft gradually rises with the tightening of the damper screw, and the plunger and the damper spring are moved. When it comes in close contact,
The pinion and the rack mesh with each other and the space between these components are pressed, and the rotation of the pinion shaft rapidly increases in proportion to the tightening of the damper screw.

The relationship between the rotational torque of the pinion shaft and the tightening force of the damper screw differs depending on the model of the rack and pinion, but it is constant for one model. By inspecting the rotational torque of several pinion shafts, Characteristic is grasped, and this data is input.

When the rotational torque detected by the rotational torque meter is compared with the characteristic of the rotational torque curve of the pinion, it is known how much the damper screw should be loosened, and the first control motor rotates reversely by that amount to tighten the damper spring. Loosen. Thus, the rotation torque of the pinion shaft can be adjusted to an appropriate torque, and a series of operations can be automated so that the gap t is minimized.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a front view of a rack and pinion meshing automatic adjusting device of a rack and pinion type front wheel steering device according to an embodiment, FIG. 2 is a partially cutaway side view of the automatic adjusting device, and FIG. 3 is a tightening angle of a damper screw. FIG. 4 is an explanatory diagram of measurement data of a rotation angle of a pinion shaft and a change in torque when is changed. FIG. 4 is an explanatory diagram of a relationship between a pinion shaft torque and a tightening angle of a damper screw.

As shown in FIGS. 1 and 2, on the upper surface of the base 20 extending in the horizontal direction, a flat plate is provided so as to stand vertically upward so that a flat surface can face the base 20. A machine frame 19, an installation table 9 positioned on the front side of the machine frame 19 to support the rack case 1 along the horizontal direction, and support legs 21 for supporting the machine frame 19 from the back side thereof; The first control motor 1 is located on the back side of the
And a support base 22 for slidably supporting the slide case 1 in a direction substantially perpendicular to the rack case 1 and in a horizontal direction by a slider portion 22a.

The rack case 1 is set on an installation table 9, and the rack case 1 is placed on the installation table 9 and fixed with a holding metal 10 from above. On the rear side of the machine frame 19, a first control motor 11 is provided on an upper portion of a support base 22 so as to be moved back and forth by an air cylinder 12.
A box-spanner-type insertion tool 13 provided at the front end of the device 1 can be fitted to the damper screw 8. On the other hand, the frame 1
9 is provided with a mounting base 18, and on the mounting base 18,
The second control motor 14 and the rotational torque meter 15 are installed in a state of being connected to a slider 18a that moves forward and backward in the length direction of the mounting base 18 by the air cylinder 17. Then, the connecting fitting 16 provided at the lower end of the rotating shaft of the rotating torque meter 15 can be lowered by the air cylinder 17 and fitted to the pinion shaft 3.

Second control motor 14, rotating torque meter 1
5. The mounting table 18 on which the air cylinder 17 is mounted
Is designed so that the vertical position and the tilt position with respect to the horizontal direction can be adjusted and fixed with respect to the machine frame 19, and can be adjusted according to the model of the rack case 1. Although not shown, the first control motor 11 and the second control motor 14 have an appropriate deceleration mechanism and a rotation angle control unit. And the first control motor 1
The first rotation torque is set to be stronger than the rotation torque of the second control motor 14.

The operation of the automatic rack and pinion engagement adjusting device according to the embodiment will be described. The rotation torque of the pinion shaft 3 changes as shown in FIG. Then, regardless of the rotational position of the pinion shaft 3, the rotational torque of the pinion shaft 3 is equal to or less than 0 ° in the figure where the damper screw 8 pushes the plunger 6 via the spring 7, as shown in FIG. Or less), the rotational torque of the pinion shaft 3 gradually increases. On the other hand, when the damper screw 8 comes into contact with the plunger 6 and presses against each part, and exceeds (becomes more than) 0 ° in the figure, the pinion increases in proportion to the tightening angle of the damper screw 8. The rotation torque of the shaft 3 increases rapidly. The characteristic of the relationship between the rotation torque 7 of the pinion shaft 3 and the tightening angle of the damper screw 8 does not change even if the rotation position of the pinion shaft 3 is changed. While inputting and storing these characteristics in a personal computer,
An appropriate position S at which the pinion shaft 3 reaches a predetermined rotational torque is stored.

First, the first control motor 11 causes the rotation torque 7 of the pinion shaft 3 to exceed a predetermined appropriate torque. For example, the damper screw 8 is tightened to the position A in FIG. In this state, the rotation torque of the pinion shaft 3 is detected by the second control motor 14 rotating the pinion shaft 3 via the rotation torque meter 15. by this,
It can be seen that the damper screw 8 is further tightened by 20 ° from the proper position. According to this data, when the first control motor 11 is rotated reversely by 20 degrees and the damper screw 8 is set at an appropriate tightening position, the pinion shaft 3 can be rotated with an appropriate rotational torque and the gap t
Can be adjusted to be minimum.

In this manner, the operation of adjusting the rotation torque of the pinion shaft 3 to the proper rotation torque and the gap t to a minimum can be automated in a series, and the operator places the rack case 1 on the installation table 9. It only needs to be attached and detached, and work can be performed without a skilled worker.

[0019]

As described above, the present invention is constructed as described above, so that the rotational torque of the pinion of the rack-and-pinion type front wheel steering system can be adjusted to the appropriate rotational torque and the clearance t.
Can be automated, and the operator only needs to attach and detach the rack case to and from the installation table, and can perform the operation without a skilled person.
Further, since the labor can be saved only by the attaching / detaching operation, a plurality of adjusting devices can be taken over, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of an adjusting device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of the adjusting device according to the embodiment of the present invention.

FIG. 3 is measurement data showing a change in rotation torque of a pinion shaft due to a change in a tightening angle of a damper screw.

FIG. 4 is a characteristic diagram showing a relationship between a rotation torque of a pinion shaft and a tightening angle of a damper screw.

FIG. 5 is a longitudinal sectional view of a pinion shaft portion of the rack and pinion type front wheel steering device.

FIG. 6 is a plan view of a rack and pinion type front wheel steering device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rack case 3 Pinion shaft 8 Damper screw 9 Installation stand 11 1st control motor 13 Fitting tool 14 2nd control motor 15 Rotary torque meter 19 Machine frame 20 Base 22 Support stand

Claims (1)

[Claims] 1. A fitting tool of a first control motor is fitted to a damper screw of a rack case of an installation table.
The rotation torque meter of the second control motor is fitted to the pinion shaft, for example, the damper screw can be tightened by the first control motor set to a strong torque, and the pinion shaft is reciprocated by the second control motor to rotate the rotation torque meter. , The rotation torque is detected, the detected value is compared with the rotation torque curve characteristics of the pinion shaft, and the tightening by the damper screw is adjusted by the first control motor based on the comparison result, so that the pinion shaft can rotate with the proper rotation torque. A rack and pinion meshing automatic adjusting device for a rack and pinion type steering device, characterized in that: