JPH0637011B2 - Preload adjustment controller for rotating shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the above-mentioned shaft when a shaft member such as a drive pinion is rotatably supported by a member such as a housing of a differential device of a vehicle via a bear rig. The present invention relates to a rotation shaft preload adjustment control device for automatically applying a desired rotation resistance (preload) to a member.

(Prior Art) A vehicle differential device includes a housing 10 as shown in FIG.
1, a drive pinion shaft 104 that is rotatably supported via tapered roller bearings 102 and 103 on the front and rear sides of the housing 101, and an inner race of the taper roller bearing 102 that is spline-fitted to the drive pinion shaft 104. Companion flange 105 that abuts 102a, and drive pinion shaft 104
Companion flange 1
05 is attached to the drive pinion shaft 104, and the inner race 10 is attached via the companion flange 105.
The drive pinion shaft 104 is provided with a pinion nut 107 that applies a desired rotational resistance (preload) to the housing 101 by pressing the drive pin 2a. A bolt insertion hole 108 is formed in the companion flange 105, and a pinion gear 109 is formed in the drive pinion shaft 104.
Is stuck.

The preload applied to the drive pinion shaft 104 can be automatically set by a preload adjusting tightening device as disclosed in Japanese Patent Publication No. 56-49691, for example. That is, the conventional tightening device of this type includes a nut rotation drive system for rotating the nut 107 and the bolt insertion hole 10 of the companion flange 105.
Insert the pin into 8 and insert this companion flange 105
That is, each of them has a companion flange rotation drive system for rotating the drive pinion shaft 104.

However, in the conventional device, the nut is tightened up to the tightening setting torque, and the preload value is measured after that.Therefore, the applied preload value depends on the inertia of the rotary drive system that constitutes the nut runner and the screw characteristics of the nut. There was a case where the preload value varied due to the influence, and it was difficult to stably give an appropriate preload value.

(Object of the Invention) The present invention solves the above-mentioned conventional problems, detects a preload value after tightening a nut to a set torque value, and compares the detected value with a reference upper limit value and a lower limit value,
An object of the present invention is to provide a preload adjustment control device for a rotary shaft, which can stably provide an appropriate preload value by performing an angle control according to an error amount, can reduce a defect (NG) rate, and can be easily automated. And

(Structure of the Invention) The present invention has a rotary drive system for rotating a nut screwed to a shaft member rotatably supported by a housing member via a tapered bearing, and the degree to which the nut is tightened. By adjusting the axial pressing force applied to the taper bearing by means of this, in the preload adjustment control device of the rotating shaft, which gives the shaft member a predetermined rotational resistance with respect to the housing member in advance, A torque detector for detecting the tightening torque, a preload detector for detecting the preload value, an angle detector for detecting the tightening angle of the nut, and a preload after the nut is tightened up to a set torque value. Judgment means for comparing the detected preload value with the reference upper limit value and the lower limit value, and the judgment result by the judgment means. Then, when the detected preload value is lower than or equal to the lower limit value, re-tightening of the nut is performed, and when the detected preload value is equal to or higher than the upper limit value, the nut is loosened, and re-tightening is performed at a loosening angle or less, and again,
And a control means for detecting the preload value and comparing it with the reference value.

With this configuration, when compared with the reference value based on the preload detection, retightening is performed below the lower limit value, and above the upper limit value, loosening and retightening below the loosening angle are performed, and recomparison is performed, It is possible to always give an appropriate preload value.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the main part of a preload adjustment control device according to the present invention. In the figure, W shows the part of the differential device described below with reference to FIG.
The nut 107 of is the threaded portion 1 of the drive pinion shaft 104.
It is temporarily fixed to the tip of 06.

Reference numeral 1 denotes a nut runner as a rotary drive head which is arranged so as to be movable up and down and has a rotary drive system. The nut runner 1 is a socket 1 fitted into a nut 107 (or a bolt).
-1, a small torque torque transducer (preload detector) 1-2 for detecting preload, a tightening torque transducer (torque detector) 1-3, and a speed reducer 1-4 for obtaining a tightening force. , A DC motor 1-5 as a drive source, and an angle encoder (angle detector) 1-6 for detecting a tightening angle. The nut runner 1 is attached to the guide bar 110 and the guide bush 11.
It is provided on a plate 113 that can be moved up and down by an air cylinder 112 through 1.

Further, a stopper 2 for protecting the minute torque transducer is provided on the plate 113, and the stopper 2 is driven by a solenoid valve 3 for driving a cylinder. Further, the plate 11
3 has an anti-rotation pin 115 through an electromagnetic clutch 114.
Is provided, and the detent pin 115 is a work W.
Is inserted into the bolt insertion hole 108 of the companion flange 105, and the electromagnetic clutch 114 is turned on and off.
Thus, the companion flange 105 and the drive pinion shaft 104 are prevented from rotating or become free.

When tightening the nut 107 and measuring the preload value, the socket 1-1 of the nut runner 1 is fitted to the nut 107, and the turning pin 115 is fitted to the bolt insertion hole 108 of the companion flange 105. Then, the electromagnetic clutch 114 is turned on to prevent the companion flange 105 from rotating, and then the nut 107
When the preload value is detected, the electromagnetic clutch 114 is turned off, and the companion flange 105
Is performed in a free state.

Reference numeral 100 denotes a control means for controlling the nut runner 1. The control means 100 receives detection signals from the minute torque transducer 1-2, the tightening torque transducer 1-3, and the angle encoder 1-6, which will be described later. The preload value set by the preload torque setting device 35 is input, and a signal for controlling the DC motor 1-5, the solenoid valve 3 for driving the stopper, and the like is output. The control means 100 also has a determination means 200 for comparing the detected preload value with a set reference value.

FIG. 2 is a block configuration of the control means 100 and the determination means 200 of the nut runner 1 including the preload torque detecting means as described above, FIG. 3 is a tightening torque diagram of the nut runner for preload detection, and FIG. 4 is the preload torque. The flowchart of the operation of the nut runner which performs detection is shown, respectively.

Hereinafter, description will be given with reference to FIGS. 2 to 4.

In this embodiment, a step of detecting the preload of the oil seal portion provided on the work W in advance is provided as a pre-stage of the preload detection.

First, the oil seal part preload detection in step S ₁ will be described. A signal indicating that the torque transducer for minute torque 1-2 and the stopper 2 for protection are ON enters the logic circuit 36 which is the main part of the control means 100, and at the same time, a start signal enters the DC motor 1-5.
Further, the logic circuit 36 opens the third gate 13 for the timer and takes in the signal from the clock generator 12. When the timer 01 setter 14 and the output from the clock generator 12 match, the comparator 15 operates to turn on the analog switch (SW) 16 to give an output to the logic circuit 36. As a result, the logic circuit 36 turns on the first gate 10 at the output stage of the torque transducer for minute torque 1-2, and starts detecting the preload torque of the oil seal portion.

On the other hand, when the outputs of the timer 02 setter 17 and the clock generator 12 match, the comparator 18 operates to turn on the analog switch 19 to give an output to the logic circuit 36. As a result, the first gate 10 is turned off and the preload torque T ₀ of the oil seal portion is stored in the peak memory 31.

Next, a description will be given of the clamping operation step S _2. At the same time that a signal indicating that the torque transducer 1-2 for minute torque and the stopper 2 for protection is ON enters the logic circuit 36, a start signal enters the motor 1-5. Torque T ₁ setting device 4 and tightening torque transducer 1-3
When the outputs of and coincide with each other, the comparator 6 operates to turn on the analog switch 8 to give a signal to the logic circuit 36. On the other hand, the logic circuit 36 operates the motor driving servo amplifier 38 to stop the motor 1-5.

Next, the operation of the preload measurement in the step S _3. Step S logic circuit 36 tightening If OK ₂ gives a signal to the solenoid valve 3, to retract the stopper 2. The logic circuit 36, which has received a backward end signal from a limit switch (not shown) attached to the stopper 2, gives a start command to the motor 1-5 and simultaneously turns on the fourth gate 20 for the timer. Timer I setting device 2
When the outputs of 1 and the clock generator 12 coincide with each other, the comparator 22 operates to turn on the analog switch 23,
The output is given to the logic circuit 36. As a result, the logic circuit 36 opens the second gate 11 at the output stage of the torque transducer 1-2 for detecting minute torque and detects the preload torque.

On the other hand, when the outputs of the timer II setter 24 and the clock generator 12 coincide with each other, the comparator 25 operates, turns on the analog switch 26, and supplies the output to the logic circuit 36. As a result, the logic circuit 36 turns off the second gate 11 and stores the preload torque T ₃ in the peak memory 32. Further, the servo amplifier 38 for driving the motor 1-5 is operated and the motor 1-5 is stopped.

Next, the operation and the determination operation of step S _4.
The actual preload torque value (T ₃ −T ₀ ) is used as the calibration torque from both the bleed torque T ₀ of the oil seal portion stored in the peak memory 31 and the total preload torque T ₃ stored in the peak memory 32. It is calculated by the calculator 33. The comparator 34 compares the calculated value with the lower limit value T _min and the upper limit value T _{max of} the allowable preload reference value set by the preload torque setting unit 35. If the comparison result is within the allowable range, that is, OK, the operation ends (END). When the value is less than or equal to the lower limit value, that is, −NG, T _min − (T ₃ −T ₀ ) is output to the torque angle calculator 43. In addition, more than the upper limit, that is, + N
In the case of G, (T ₃ −T ₀ ) −T _max is output to the torque angle calculator 43. The torque angle calculator 43 calculates a loosening or tightening angle from the excess or deficient torque value. The conversion factor experimentally obtained here is 5.6 Kgcm / °. It is to be noted that the step S ₄ is not come appear in Figure 3.

Next, a description will be given of increased tightening or loosening operation in step S _5.

When the -NG or + NG in step _{S 4} the logic circuit 36 provides a signal to the solenoid valve 3 causes ON stopper 2. A limit switch attached to the stopper 2 gives a signal at the forward end to the logic circuit 36.

First, the operation when -NG is described below. The logic circuit 36 gives the torque T ₂ or T ₄ setting device 5 the peak torque T ₂ (FIG. 3) in step S ₂ .
The logic circuit 36 gives a rotation command to the motor 1-5.
When the output of the tightening torque transducer 1-3 and the output of the torque setting device 5 coincide with each other, the comparator 7 is activated, the analog switch 9 is turned on, and the logic circuit 3 is turned on.
Signal to 6. The logic circuit 36 opens the sixth angle gate 39 at the output stage of the angle encoder 1-6 and causes the counter 40 to count the rotation angle.

On the other hand, the output of the theoretical tightening / angle setting device 42 based on the value calculated by the torque angle calculator 43 and the counter 40 are compared by the comparator 41, and the output is given to the logic circuit 36.

Next, the operation at + NG will be described below. The logic circuit 36 causes the torque setter 5 to calculate T ₂ × 0.6 = T ₄ from the peak torque T ₂ in step S ₂ by the calculator 37. At the same time, the logic circuit 36 gives a reverse rotation signal to the motor 1-5, and when the output of the tightening torque transducer 1-3 and the output of the torque setting device 5 coincide, the comparator 7 is activated and the analog switch 9 is turned on. A signal is given to the logic circuit 36.

The logic circuit 36 outputs a stall command to the servo amplifier 38 of the motor 1-5 and turns on the fifth timer gate 27. When the outputs of the timer III (stall timer) setter 28 and the clock generator 12 coincide with each other, the comparator 29 is activated and the output is given to the logic circuit 36. The logic circuit 36 gives a restart signal to the servo amplifier 38 and opens the sixth gate 39 to take in the loosening angle.

On the other hand, a signal is given to the logic circuit 36 by the comparator 41 comparing the output of the theoretical tightening / angle setting device 42 and the output of the counter 40 with the value calculated by the torque angle calculator 43.

Finally, describing the preload detecting operation in step S _6. In step S ₆ in the same manner as in Step S ₃ measures the preload torque again, the operation ends if the in clogging OK range detection preload value is allowable reference value (END), the range of the reference value outside clogging If NG, N
The G output is given to the logic circuit 36. Although not shown, a display means is provided for displaying OK or NG depending on whether the detected preload value is within the reference value or deviates from the reference value by the output of the logic circuit 36.

After tightening the nut to the set torque value as described above, the preload value is detected, the detected preload value is compared with the upper and lower limit values of the reference value, and re-tightening including angle control is performed according to each error amount. Since the preload value is detected again and the preload value is detected again, an appropriate preload value can be surely given.

It should be noted that the above-described embodiment has been described as having a step of detecting the preload of the oil seal portion before the tightening operation of the nut, but the present invention is limited to one including the step of detecting the preload of the oil seal portion. Not a thing. Further, as in the above embodiment, the tightening torque and the preload are measured by using the same drive source and by using two different types of torque transducers, which greatly contributes to the cost reduction and space saving of the apparatus itself.

As described above, according to the present invention, when the nut of the rotary shaft is tightened by using the rotary drive system such as the nut runner and the preload value of the rotary shaft is adjusted to the reference value, the detected preload value is detected. Is compared with the reference value, and re-tightening is performed below the lower limit value, and re-tightening is performed below the upper limit value and below the loosening angle and the slack angle, and then re-compared.
Angle control is performed according to the amount of error, and the preload value that is given is less affected by the inertia of the rotating system and screw characteristics compared to the conventional tightening device, and it is possible to give a proper preload value in a stable manner. (NG) rate is reduced and automation is facilitated.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a rotary shaft preload adjustment control device of the present invention, FIG. 2 is a block diagram showing details of a rotary drive system and control means in the same device, and FIG. Torque diagram against time for
FIG. 5 is a flow chart of control of the device, and FIG. 5 is a sectional view showing an example of a differential device to which the device of the present invention is applied. 1 …… Nutrunner (including rotary drive system) 1-1 ……
Socket 1-2, torque transducer for micro torque (preload detector), 1-3 ... torque transducer for tightening (torque detector), 1-5 ... DC motor, 1-6 ... angle encoder ( Angle detector), 36 ...
... preload torque setting device, 100 ... control means, 20
0 ... Judgment means, W ... Work, 101 ... Housing, 102, 103 ... Tapered roller bearing, 1
04 ... Drive pinion shaft (shaft member), 105 ... companion flange, 106 ... screw part, 107 ... nut.

Claims (1)

[Claims] 1. A rotary drive system for rotating a nut screwed on a shaft member rotatably supported by a housing member via a taper bearing, and the taper bearing according to the degree to which the nut is tightened. The torque for tightening the nut is detected in the preload adjustment control device for the rotating shaft, in which the axial pressing force applied to the shaft member is adjusted to thereby give the shaft member a predetermined rotation resistance with respect to the housing member in advance. A torque detector, a preload detector that detects the preload value, an angle detector that detects the tightening angle of the nut, and a preload after the nut is tightened to a set torque value, and the detected preload value Based on the judgment result by the judgment means and the judgment upper limit value and the lower limit value. When the load value is less than or equal to the lower limit value, re-tightening of the nut is performed.When the load value is greater than or equal to the upper limit value, the nut is loosened, and re-tightening is performed at a slack angle or less, and the preload value is detected again and the reference A preload adjustment control device for a rotating shaft, comprising: a control means for comparing with a value.