JPS584367A - Motor tool which can detect angle of revolution after predetermined torque - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power tool that can detect the rotation angle of a drive shaft after a certain torque, and therefore can discriminate and control the rotation angle of a drive shaft after a certain torque.

Conventionally, power tools such as impact wrenches and nut runners use the reaction force of the rotational force of a drive shaft driven by an air motor to act on a torsion bar, and detect the entire tightening torque based on the torsion angle of the torsion bar. A device that controls torque is known.

However, although this type of power tool can detect tightening torque, it has the disadvantage that it cannot accurately detect the rotation angle of a nut, etc. after a certain tightening torque, and cannot accurately control the rotation angle. .

The purpose of this invention is to eliminate the above-mentioned drawbacks,
The rotation angle of the drive shaft after a certain tightening torque can be accurately detected, and the rotation angle of the drive shaft after a certain tightening torque can be determined.
The object of the present invention is to provide a new power tool that can be controlled.

In order to achieve the above-mentioned object, the present invention provides a motor which receives rotational reaction force of a drive shaft driven by an air motor.
:y bar (torque sensor that detects the D rotation angle.

A rotation angle sensor is provided to detect the rotation angle of the shaft or drive shaft of the air motor, and the output signal of the torque sensor is used to detect a constant tightening torque. It is characterized in that the rotation angle of the drive shaft is detected.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

In FIG. 1, 1.2 are nut runners of the same structure fixed in parallel to the underframe 8, 4.5 are TA191 switching valves that control the air supply to the nut runners 1.2, and 6
is a torque-angle control device.

The nut runner 1 transmits the l11 rotor of the air motor 11 to the drive shaft 1B via a planetary gear/wheel mechanism 12 as an example of a transmission mechanism, increases and decelerates the rotational force 2 of the air motor 11, and decelerates the rotational speed of the air motor 11 to the drive shaft. I'm trying to tell 18.

The rotational force of the drive shaft 18 is applied to the upper end of the torsion part 14 via the planetary gear 12B.

The torsion bar 14 is connected to the drive shaft 18 as shown in FIG.
The flange portions 14a at the lower end are fixed to the underframe 3 with bolts 15, as shown in FIG. Therefore, Natsutran'tllll'1! Since the torsion par 14 is fixed to the underframe 8 via a lion/<-14, the torsion par 14 is twisted by a nine-fold force in accordance with the tightening torque of the drive shaft 18.

The case 1211 of the planetary gear mechanism 12 includes the case 7.
A par 21 extending in the radial direction of the par 12a is fixed, and when the torsion bar 14 is twisted, the par 21'' rotates together with the case 12a. A torque sensor consisting of a limit switch 22 is provided, and when the tightening torque of the drive shaft 18 becomes a constant value and the lever 21 is twisted by a certain angle, the lever 21 is A torque sensor 22 is pressed against the tip, and the torque sensor 22 detects a constant torque via the twist angle of the torsion bar 14.

(Above) When the torque sensor 22 detects the bipedal torque, the output signal from the torque sensor 22 causes the electromagnetic switching valve 4 to
is turned off to stop the driving of the nut runner 1 and output a signal to the torque-angle control device 6 indicating that the tightening torque has reached a constant value.

On the other hand, a rotation angle detection shaft 25 is fixed to the rotation shaft (not shown) of the air motor 11, and the center of a disc 27 is fixed to the tip of the shaft 25, and the center of the disc 27 is fixed at equal intervals on a circle with a constant diameter. One or more through holes 26 are provided. Further, as shown in FIG. 4, a U is formed by sandwiching the upper and lower portions of the circular hole 26 of the disk 270 between a light emitting element and a light receiving element (not shown).
A character-shaped non-contact rotation angle sensor 28 is provided on the underframe 3, and as the air motor 11 rotates, the light emitting element and the light receiving wife are made to face each other via the circular through hole 26, so that the rotation angle sensor 28 outputs pulses. That's what I do.

After the torque sensor 22 outputs a signal indicating a predetermined constant torque Ts (snag torque), the pulse from the rotation angle sensor 28 is transmitted to the amplifier 65 of the Y-route angle control device 6 as shown in FIG. via counter 66
It is designed to be input. The counter 66 counts the number of pulses and calculates the number of pulses for the drive shaft 1 after the snug torque Ts.
A signal representing the rotation angle θ of 8 is input to comparators 67 and 68. The comparator 67 compares the signal representing the target angle θC inputted from the target angle setting device 69 with the signal representing the actual rotation angle θ of the drive shaft 18, and determines when the actual rotation angle θ reaches the target rotation angle θC. , a signal for turning off the electromagnetic switching valve 4 is output via the drive circuit 70. On the other hand, the comparator 68 receives a signal representing the lower limit rotation angle θ1 output from the lower limit setting device 71, and
A signal representing the upper limit rotation angle e2 outputted from the upper limit setting device 72 is inputted, and the actual rotation angle e is compared with the lower limit rotation angle θ1 and the upper limit rotation angle e2,
When θ≦01, the lamp 5 is
If #1<e<θ2, a signal to light the lamp 51 is outputted via the drive circuit 73, and when #1<e<θ2, a signal to light the lamp 51 is outputted.

In this case, a signal for lighting the lamp 58 is outputted via the drive circuit 78. Therefore, the sixth
As shown in the figure, the drive shaft 18 after the snug torque Ts
If the rotation angle θ is within the allowable range with respect to the target rotation angle θC, that is, if θ<02, the lamp 51 indicating a passing condition is lit, and if θ≦θ, it indicates an insufficient rotation angle condition. Rumph.

52 is lit, and if θ≧02, a lamp 58 indicating an excessive rotation angle condition is lit.

On the other hand, the nut runner 2 has the same structure as the nut runner 1, and is equipped with a limit switch 82 as a torque sensor and a rotation angle sensor 38, and their output signals are torque - The signal is processed in the angle control device 6 in the same manner as in the case of the nut runner 1.

On the other hand, lever switches 41 and 42 are provided at both ends of the lower part of the underframe 8, respectively. When the lever switch 41 is turned on, the electromagnetic switching valves 4.5 are also turned on, and air is supplied to the air motor of the nut runner 1.2 to rotate the nut runner 1.2. Lever switch 42
When turned on, both solenoid switching valves 4 and 5 are turned on,
In addition to driving the nut runners 1 and 2, the torque sensor 2
When both of the rotation angle sensors 28 and 88 are detecting snug torque, the signals from the rotation angle sensors 28 and 88 are input to the counter of the torque angle control device 6.

The torque-angle control device 6 includes each torque sensor 22.8.
When the respective tightening torques of the drive shafts 18.80 of the nut runner 1.2 exceed a certain torque or Kununag torque Ts, the respective lamps 46.
47, and further includes a circuit (not shown) for logically determining the output signals from the torque sensors 22 and 82, and when the tightening torques of both drives *d118.80 are both greater than or equal to the snug torque Ts based on the output signal of the logic circuit. A comprehensive torque pass lamp 48 is provided which lights up. In addition, the above torque -
In order to indicate the tightening torque of the nut runner 2 similarly to the lamps 51, 52, and 58 indicating the tightening torque of the nut runner 1, the angle control device 6 is configured such that the rotation angle θ of the drive shaft 80 after the snagging torque Ts is (θ ≦01), a pass lamp 54 that lights up when (ol<θ x θ2), and a lamp 56 that lights up when (θ2≦θ), and a pass lamp 46 that lights up when (θ2≦θ). .47 are both lit, the overall torque pass lamp 48 is lit when both pass lamps 51 and 55 are lit, and the pass lamp 48.51.55 is lit when both pass lamps 51 and 55 are lit.
A general rejection lamp 57 is provided which turns off when any one of them goes out.

Note that 59 is a power lamp, and 61 is a manual automatic changeover switch.

The power tool configured as described above operates as follows.

First, the coupling fittings 81 and 82 at the tips of the drive shafts 18 and 80 are respectively fitted into nuts (not shown) to be fastened.

Next, turn on the lever switch 41 on the right side in FIG. 1, turn on both the electromagnetic switching valves 4 and 5, turn on both the nut runner and 2'ft, and tighten the nut.

When the tightening torque of each nut reaches the snug torque Ts, the torque sensors 22, 82 are turned on due to the twisting of the torque sensors 14, 81, turning off the electromagnetic switching valves 4, 5, and the nut runner 2 is rotated. to stop. Then, the lamps 46 and 47 of the torque-angle control device 6 and the total torque pass lamp 48 are turned on.

Next, when the lever 7 switch 42 on the left side in FIG.
g, 88 starts reading the rotation angle of the drive shaft 18.80 and inputs the bulk to the torque-angle control device 6.

The torque-angle control device 6 performs signal processing as described above, and when the rotation angle e of the drive shaft 18.80 after the snug torque T@ reaches the target rotation angle eC, the electromagnetic switching valve 4
A signal is output to turn off each of the nut runners 5 and 20 to stop the nut runner. However, drive shaft 1: (,
80 does not necessarily stop at the moment when the target rotation angle θC is reached due to the delay in transmission of the signal and the inertia of the nut runners 1 and 2.

On the other hand, at this time, the torque-angle control device 6 controls the drive shaft 18.
The rotation angle θ after the nunag torque Ts when the 80 actually stops is compared with the lower limit value θl and the upper limit value θ2, and the test is passed if the rotation angle θ of the drive shaft 13 is (θ1 × θ × θ2). Turn on the lamp 51 and set the rotation angle θ of the drive shaft 3o.
When is (θ1 x θ x θ2), the pass lamp 54 is turned on, and when the pass lamps 51, 54 and the total torque pass lamp 48 are both lit, the total pass lamp 58 is turned on. Otherwise, overall failure lamp 5
Turn on 7. Thereby, the rotation angle of the drive shaft 18.80 after the nunag torque Ts can be accurately determined and controlled.

In the above embodiment, part of the drive control of the nut runners 1 and 2 was carried out manually by operating the drive control t-lever switches 41 and 42, but the lever switch 41 was used as the starting switch and the subsequent operations were performed without operating the lever switch 42. may be performed automatically.

Furthermore, it goes without saying that the present invention can be applied to any number of absentee tools, not just two.

As is clear from the above description, the present invention includes a torque sensor that detects a constant rotation angle of a torsion bar that receives a rotational reaction force of a drive shaft driven by an air motor, and a torque sensor that detects a rotation angle of the shaft of the air motor or drive shaft. A rotation angle sensor is provided, and the constant tightening torque is detected by the output signal of the torque sensor, and the rotation angle sensor is configured to detect the rotation angle of the drive shaft after the constant tightening torque. The rotation angle of the drive shaft after a certain tightening torque can be accurately detected, and the rotation angle of the drive shaft after a certain tightening torque can be determined and controlled.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an embodiment of the present invention, Fig. 2 is a sectional view of the torsion bar portion of the nut runner, and Fig. 3 is a cross-sectional view of the torsion bar of the nut runner.
Figure 4 is a perspective view of the rotation angle sensor, Figure 5 is a block diagram of the main parts of the torque-angle control device, and Figure 6 shows the rotation angle and tightening torque of the drive shaft. FIG. 1.2... Nut runner, ll... Air motor, 18.80... Drive shaft, 14.81... Torsion pad, 22.82... Torque sensor, 28.8
8...Rotation angle sensor.

Claims (1)

[Claims] (1) The drive shaft is rotated by an air motor to tighten the object to be tightened, and the reaction force of the rotational force of the drive shaft is applied to the torsion bar, and the tightening torque is detected by the rotation angle of the torsion bar. A power tool comprising: a torque sensor that detects a certain rotation angle of the jumper and outputs a certain torque tm; and a rotation angle sensor that detects a rotation angle of the shaft or drive shaft of the air motor; A constant tightening torque is detected based on an output signal, and the rotation angle sensor is configured to detect a rotation angle of the drive shaft after the constant tightening torque.Detecting the rotation angle after the constant torque Power tools that can.