JPH07120335A - Apparatus for detecting torque - Google Patents

Abstract

PURPOSE:To automatically clear a display of a maximum value of a detected torque and a report of judged result of a normal area in an optionally set time and to detect a correct torque efficiently. CONSTITUTION:The apparatus is provided with a clearing means for automatically clearing the maximum value of a detected torque displayed on a display 15 and the judged result of a normal area informed by informing means 16, 17 after an optionally set time has passed, and returning the apparatus to the state before the maximum value of the detected torque is judged. A timer 14 of the clearing means starts to measure a time from the time when a torque detected by a torque-detecting circuit 11 decreased to be smaller than a threshold value after the torque become larger than the threshold value in time sequence to the time when the clearing mean clears.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque detecting device for calculating a maximum torque value detected by a torque detecting section and displaying it on a display section.

[0002]

2. Description of the Related Art A conventional torque detecting device of this type displays a detected torque maximum value on a display portion, or makes a normal range determination of the detected torque maximum value and notifies the result of the determination by an informing means. The user operates the switch provided in the torque detection device to clear the displayed maximum detected torque value or the notified normal range determination result. In addition, there is a similar measuring instrument that automatically clears the display or the notification after a lapse of a prescribed time, but the time was constant.

[0003]

However, in the case of using a switch, the user must manually clear the displayed detected torque maximum value and the informed normal range determination result. The operator must necessarily operate the switch between the screw tightening work and the next screw tightening work, resulting in a decrease in work efficiency. Moreover, when the switch operation was forgotten, the torque could not be detected.

On the other hand, in the case of clearing the display and notification after the lapse of the specified time, the time is constant and if this is short with respect to the working condition, the user will perform the display and notification within the specified time due to the surrounding environment. I can not confirm it, on the contrary, if it is long,
Even after confirming the display and notification, the next screw tightening work cannot be executed immediately, and a waiting time occurs, resulting in a decrease in work efficiency. Furthermore, even if the display and notification are cleared after the specified time has elapsed, if the time measurement start point is not appropriate, the display and notification will be changed from the display of the maximum detected torque value and the notification of the normal range determination result due to the screw length. The time until clearing changes, and there will be a difference between the measured specified time and the actual specified time.

Therefore, an object of the present invention is to solve the above-mentioned problems and to automatically clear the display of the detected torque maximum value and the notification of the normal range discrimination result at an arbitrarily set time. To provide.

[0006]

According to the torque detecting device of the present invention, the detected torque maximum value displayed on the display unit and the normal range determination result notified by the notifying unit are set for an arbitrarily set time. It is characterized in that it further comprises a clearing means for automatically clearing and returning to a state before the detection torque maximum value determination.

The time until the clearing by the clearing means can be arbitrarily set by the setting means. Further, the clearing means is configured to start measuring the time from when the torque value detected by the torque detecting unit becomes smaller than a threshold value in time series to when the torque value becomes smaller than the threshold value until the torque value is cleared. And In this case, the threshold value can be calculated from the lower limit value of the normal range set by the normal range setting means.

[0008]

According to this torque detecting device, the display of the detected torque maximum value and the notification of the normal range determination result can be automatically cleared at an arbitrarily set time. The time until the clearing is started from the time when the torque value detected by the torque detection unit exceeds a certain threshold value and becomes below the threshold value again.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows a system configuration of a torque detection device according to the present invention. This system is mainly composed of a CPU 10 having various functions such as control, calculation, comparison and the like, in addition to this, a torque detection circuit 11, a 10 key 12 which is an input setting means, a memory (RAM) 13 and a clearing timer 14. And indicator 1
5 is connected to a buzzer 16 and an LED (light emitting diode) 17 which are notification means.

The torque detection circuit 11 detects the screw tightening torque and inputs a signal corresponding to it to the CPU 10.
FIG. 2 shows the detected torque value as an analog waveform with the horizontal axis as the time axis. The 10 key 12 is for inputting and setting the normal range of the detected torque maximum value, and also for inputting and setting the clear time, that is, the time for clearing the display of the display unit 15 and the notification of the buzzer 16 and the LED 17. The memory 13 always stores some normal range set value, and also stores the detected torque maximum value. The CPU 10 inputs and compares the torque values detected by the torque detection circuit 11 in time series to calculate the maximum value of the detected torque, and the detected torque maximum value is a value within the normal range stored in the memory 13. Or not. Buzzer 16 and LE
D17 notifies the determination result. The timer 14 measures the time to clear the notification of the buzzer 16 and the LED 17, and is controlled by the CPU 10. The time measurement is such that the torque value detected by the torque detection circuit 11 exceeds a certain threshold value shown in FIG. After that, it starts again from the time when it becomes below the threshold again.

FIG. 3 is a state transition diagram during operation of this torque detection device. The operation will be described below with reference to this figure. In addition, the time to clear the normal range and display / notification is
Set as already set.

When the torque detection operation is started, the state becomes 0 in FIG. 3, the data such as the past detected torque maximum value and the normal region discrimination result notification is cleared, and the state 1 is entered. When the state 1 is entered, the output from the torque detection circuit 11 is sampled, the detected torque maximum value is newly calculated and compared with the previous calculated value, and if the new calculated value is large, it is updated and stored in the memory 13. To do. Then, the detected torque maximum value is displayed on the display unit 15, and the sampled torque value is compared with the threshold value. If the comparison result is the sampling value ≧ threshold value, the state 2 is entered, and if not, the state 1 is repeated.

In state 2, the same processing as in state 1 is performed, but
If the comparison result of the sampled torque value and the threshold value is the sampling value> the threshold value, the state 2 is repeated. If the sampling value ≦ the threshold value, the torque measurement is stopped and the time value preset in the timer 14 is set. Is set and is started, and then the state 3 is entered.

In state 3, it is determined whether or not the maximum detected torque value is within a preset normal range, and the determination result is output to the buzzer 16 and the LED 17, which are the informing means.
The timer 14 is monitored, and when the time measured by the timer 14 reaches the set time, the state is returned to 0.

When the state is returned to the state 0, the data such as the detected torque maximum value and the normal region discrimination result notification are cleared as described above, and the torque detection operation is performed again. The threshold value may be set arbitrarily, but is, for example, 1/2 of the lower limit value of the normal range.
Alternatively, if it is automatically set to 2/3, the number of setting items for the user can be reduced.

[0016]

According to the present invention, the display of the maximum value of the detected torque and the notification of the normal range determination result can be automatically cleared at a time arbitrarily set. According to the third aspect of the present invention, the time until it is cleared is measured efficiently when the torque value detected by the torque detection unit exceeds a certain threshold and then becomes less than or equal to the threshold again. Accurate torque detection can be performed. According to the fourth aspect, the threshold value can be automatically set from the lower limit value of the normal range, and the setting items of the user can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of a torque detection device according to the present invention.

FIG. 2 is a graph showing a torque value detected by the torque detection device as an analog waveform with a horizontal axis representing a time axis.

FIG. 3 is a state transition diagram during operation of the torque detection device.

[Explanation of symbols]

 10 CPU 11 Torque Detection Circuit 12 10 Key 13 Memory 14 Clear Timer 15 Display 16 Buzzer 17 LED

Claims (4)

[Claims] 1. A torque detection unit for detecting a tightening torque of a screw, and a detected torque maximum value calculation for calculating and calculating a maximum value of the detected torque by inputting and comparing the torque values detected by the torque detection unit in time series. Means, a display section for displaying the detected torque maximum value, a normal range setting means for setting a normal range of the detected torque maximum value in advance, and a detection for determining whether or not the detected torque maximum value is within the normal range. In a torque detection device having a torque maximum value determination means and an informing means for informing the determination result, the detected torque maximum value displayed on the display unit and the determination result informed by the informing means,
A torque detecting device, comprising: a clearing unit that automatically clears after a lapse of a set time set arbitrarily and returns to a state before a maximum detected torque value is determined. 2. The torque detection device according to claim 1, further comprising setting means capable of arbitrarily inputting and setting a time until the clearing by the clearing means. 3. The clearing means measures the time from when the torque value detected by the torque detection unit becomes smaller than a threshold value in time series to when the torque value becomes smaller than the threshold value until the torque value is cleared. 1 is started.
Alternatively, the torque detection device described in 2. 4. The torque detection device according to claim 3, wherein the threshold value is calculated from a lower limit value of the normal range set by the normal range setting means.