JP4804790B2 - Screw tightening management device for torque control wrench - Google Patents

Description

  The present invention relates to a screw tightening management device for an air motor driven torque control wrench.

Conventionally, in a torque control wrench used for tightening bolts, nuts, etc. (referred to as “screws” in this specification), management of screw tightening work, for example, management of the number of screw tightening, It was performed by a controller that manages screw tightening work such as the number of screw tightening, which is connected to a control wrench via an air hose or cable, or connected wirelessly.
In the case of an air motor-driven torque control wrench, the management of screw tightening work is performed by shutting down the operation of an operation stop mechanism that stops the operation of the wrench upon detecting that the screw tightening torque has reached a predetermined value. Detection is made by the operation of the off-valve or the change in the pressure of the high-pressure air that operates the air motor, and based on this, the number of tightened screws is managed (see Patent Document 1).
However, with this method, although the number of tightening of screws can be managed, the tightening quality of each screw is controlled by detecting that the screw tightening torque has reached a predetermined value and stopping the operation of the wrench. Since it depends on the stop mechanism, it is difficult to manage the tightening quality of the screw at a level exceeding the function of the stop mechanism.
Japanese Unexamined Patent Publication No. 6-321381

  In view of the problems of the screw tightening work management device in the conventional torque control wrench described above, the present invention provides a screw tightening work in a torque control wrench capable of managing the tightening quality of each screw with high accuracy. An object of the present invention is to provide a management apparatus.

In order to achieve the above object, a screw tightening work management device in a torque control wrench of the present invention includes an air motor, a hydraulic impact torque generating device driven by the air motor and applying impact torque to an output shaft, and screw tightening. In a screw tightening management device for a torque control wrench comprising an operation stop mechanism that senses that the attached torque has reached a predetermined value and stops the operation of the wrench , the air motor is disposed on the back side of the shutoff valve. A high-pressure air extraction member is provided, and the high-pressure air that operates the air motor is drawn out of the torque control wrench via the extraction member and the air hose, and hydraulic impact torque is generated at the end of the air hose. It detects the pressure of the high pressure air at the supply position to the air motor occurring according to the impact torque device The pressure sensor is provided to detect a change in pressure of the high pressure air generated in response to impact torque of the hydraulic impact torque generator by pressure sensors, the cable and converts the change in the pressure of the high pressure air which is detected in the electrical signal Via a torque control wrench, which is transmitted to a controller for managing screw tightening work separately from the torque control wrench, and the controller measures the number of occurrences of impact torque from the change in pressure of the high-pressure air. To do.

According to the screw tightening work management device in the torque control wrench of the present invention, the number of occurrences of impact torque until the screw tightening is completed is further managed in real time for each screw as necessary. It is possible to control the tightening quality of each screw with high accuracy.

Then , a change in the pressure of the high-pressure air generated corresponding to the impact torque of the hydraulic impact torque generator detected by the pressure sensor is transmitted to a controller that manages the screw tightening work provided separately from the torque control wrench, and the controller Thus, by measuring the number of occurrences of the impact torque from the change in the pressure of the high-pressure air, the screw tightening work can be managed centrally by a controller provided separately from the torque control wrench.

  Further, by externally attaching the pressure sensor to the torque control wrench, the screw tightening management device in the torque control wrench of the present invention can be easily applied to a general-purpose torque control wrench.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a screw tightening management device in a torque control wrench of the present invention will be described below with reference to the drawings.

1 to 2 show an embodiment of an air motor-driven torque control wrench to which a screw tightening management device in a torque control wrench of the present invention is applied.
This torque control wrench 1 driven by an air motor includes a main valve 11 that supplies and stops high-pressure air, an operation lever 12 that operates the main valve 11, and an air motor 13 that generates rotational torque by the supplied high-pressure air. And a hydraulic striking torque generator 14 that converts the rotational torque of the air motor 13 into a striking torque. The basic configuration and operation of the entire device are conventionally known (if necessary, for example, No. 1-29012, JP-A-6-321381, JP-A-10-15843, etc.).

The torque control wrench 1 also includes an operation stop mechanism 2 that detects that the screw tightening torque has reached a predetermined value and stops the operation of the wrench.
Various known mechanisms can be used for the operation stop mechanism 2. In this embodiment, a hole penetrating the axis of the air motor 13 is formed, and the rod 21 is slid in the hole. The piston 22 is provided on one end side of the rod 21, the piston 22 is disposed in a cylinder 14b provided on the liner upper lid 14a, and the end surface of the output shaft 15 is opposed to the liner upper lid 14a. To face.
When the pressure in the high pressure chamber of the hydraulic striking torque generator 14 disposed on the output shaft 15 side of the cylinder 14b and the pressure adjusting mechanism 23 of the hydraulic striking torque generator 14 reaches a preset pressure, the hydraulic oil The relief valve 23a for releasing the air is communicated via a small-diameter passage 14c.
Further, a shut-off valve 25 is provided at the other end of the rod 21, and the pilot valve 24 is operated by moving the rod 21 to open the rod 21 side of the shut-off valve 25 to the atmosphere. Is closed.

The torque control wrench 1 rotates the hydraulic striking torque generator 14 by operating the operation lever 12 to open the main valve 11, supplying high pressure air to the air motor 13 and driving the air motor 13. And hitting torque is generated.
At this time, the relief valve 23a of the pressure adjusting mechanism 23 is pressed to the pressure adjusting mechanism 23 side by the biasing force of the spring until the pressure in the high pressure chamber of the hydraulic impact torque generating device 14 reaches a preset pressure. Instead, the screw is tightened while generating an impact torque.
However, when the tightening of the screw progresses and the screw is tightened with a desired tightening torque, the pressure in the high-pressure chamber rises to the set pressure. The valve 23a is opened against the urging force of the spring and is introduced into the cylinder 14b through the passage 14c. The pressure of the hydraulic oil acts on the piston 22 to press and slide the rod 21. The pilot valve 24 is operated by moving the rod to release the rod 21 side of the shut-off valve 25 to the atmosphere, so that the shut-off valve 25 is closed.
By closing the shut-off valve 25, the supply of high-pressure air to the air motor 13 is shut off, and the air motor 13 is automatically stopped to complete the operation of tightening the screw to a desired tightening torque.

  The air motor 13 configured as described above, the hydraulic striking torque generator 14 that is driven by the air motor 13 and applies the striking torque to the output shaft 15, and senses that the screw tightening torque has reached a predetermined value. In the air motor type torque control wrench 1 having an operation stop mechanism 2 for stopping the operation of the wrench, a pressure sensor 3 for detecting the pressure at the supply position of the high pressure air that operates the air motor 13 to the air motor 13 is provided. The pressure sensor 3 detects a change in the pressure of the high-pressure air generated in response to the impact torque of the hydraulic impact torque generating device 14, and measures the number of occurrences of the impact torque from the change in the pressure of the high-pressure air. .

The pressure at the supply position of the high-pressure air that operates the air motor 13 to the air motor 13 is taken out by an appropriate pressure take-out mechanism 4, specifically, in this embodiment, the back side of the shut-off valve 25 (the rod 21 On the other side, a high-pressure air take-out member 41 that operates the air motor 13 is provided, and is drawn out of the torque control wrench 1 via the air hose 42.
And the pressure sensor 3 which detects a pressure is provided in the edge part of this air hose 42, This pressure sensor 3 detects the change of the pressure of the high pressure air which respond | corresponds to the striking torque of the hydraulic striking torque generator 14, The detected change in the pressure of the high-pressure air is converted into an electrical signal, which is transmitted to the controller 6 that manages the screw tightening work provided separately from the torque control wrench 1 via the cable 5. The number of occurrences of impact torque is measured from changes in air pressure.

In this case, the material and length of the air hose 42 are appropriately selected so that the pressure of the high pressure air is not attenuated (the change in pressure is not leveled) so that the change in the pressure of the high pressure air can be accurately detected. In addition, the pressure sensor 3 may be directly connected to the torque control wrench 1 (such as the high-pressure air extraction member 41 that operates the air motor 13) or may be built in (reference example) .
Further, the electrical signal of the change in the pressure of the high-pressure air detected by the pressure sensor 3 is transmitted to the controller 6 via the cable 5 and is also transmitted to the controller 6 via radio, or provided in the torque control wrench 1. Information can also be processed by a controller (not shown).
Furthermore, the controller 6 can perform information processing and display appropriate information by connecting to a computer.

FIG. 3 shows an example of a measurement result obtained by measuring a change in pressure at a supply position of high-pressure air that operates the air motor to the air motor when one screw is tightened.
The tightening operation shown in FIG. 3 includes a tightening start pressure set value: 0.40 MPa, a shut-off pressure set value of 0.53 MPa, a tightening time (a striking torque generation time (from the start of striking torque generation, the shut-off valve 25 The time until the closing operation of) was 0.428 seconds, the number of pulses (the number of times the impact torque was generated) was 15 times, and it was confirmed that the screw was tightened satisfactorily.
Here, in the tightening operation of the screw, in the case of tightening time (occurrence time of impact torque): 0.150 to 0.429 seconds, number of pulses (occurrence number of impact torque): 5 to 14 times, It is assumed that the screw tightening work was performed well.

  On the other hand, FIG. 4 shows the results of tightening time (occurrence time of impact torque), number of pulses (occurrence number of impact torque) and determination (adequacy of tightening operation) when 20 screws are tightened. An example is shown below. Note that this example is set so that poor tightening work frequently occurs (screw failure, etc.). In actual screw tightening work, it is difficult to cause frequent tightening work failures like this example. Absent.

  The screw tightening management device in this torque control wrench is provided with a pressure sensor 3 for detecting the pressure at the supply position of the high-pressure air that operates the air motor 13 to the air motor 13, and the pressure sensor 3 generates hydraulic striking torque. By detecting the change in the pressure of the high-pressure air generated in response to the impact torque of the device 14 and measuring the number of occurrences of the impact torque from the change in the pressure of the high-pressure air, the screw tightening is completed. The number of occurrences of the impact torque can be managed for each screw in real time as needed, and the tightening quality of each screw can be managed with high accuracy.

  Further, the change in the pressure of the high-pressure air generated corresponding to the impact torque of the hydraulic impact torque generator 14 detected by the pressure sensor 3 is transmitted to the controller 6 that manages the screw tightening work provided separately from the torque control wrench 1. At the same time, in this controller 6, the number of occurrences of the impact torque is measured from the change in the pressure of the high-pressure air, so that the screw tightening work is managed centrally by the controller 6 provided separately from the torque control wrench 1. It can be carried out.

  Further, by externally attaching the pressure sensor 3 to the torque control wrench 1, a general-purpose torque control wrench 1 can be easily applied with a screw tightening management device in the torque control wrench 1.

  In addition, by measuring the generation time of the impact torque, in addition to the number of occurrences of the impact torque until the tightening of the screw is completed, the occurrence time of the impact torque, that is, the time required for tightening the screw Further, each screw can be managed in real time as required, and the tightening quality of each screw can be managed with higher accuracy.

  As mentioned above, although the management apparatus of the screw fastening operation | work in the torque control wrench of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, It deviates from the meaning. The configuration can be appropriately changed within a range not to be performed.

  The screw tightening work management device in the torque control wrench of the present invention can manage the tightening quality of each screw with high accuracy. It can be used suitably for the use of a management apparatus.

It is a conceptual diagram which shows one Example of the management apparatus of the screw fastening operation | work in the torque control wrench of this invention. It is explanatory drawing which shows the air motor type torque control wrench used for this invention, (a) is front sectional drawing, (b) is AA sectional drawing of (a). It is explanatory drawing which shows an example of the measurement result which measured the change of the pressure in the supply position to the air motor of the high pressure air which act | operates an air motor at the time of the fastening operation | work of one screw. An example is shown summarizing the results of tightening time (hitting torque generation time) and number of pulses (number of times of hitting torque generation) and determination (success / failure of tightening work) when 20 screws are tightened. It is explanatory drawing.

DESCRIPTION OF SYMBOLS 1 Torque control wrench 11 Main valve 12 Operation lever 13 Air motor 14 Hydraulic striking torque generator 15 Output shaft 2 Operation stop mechanism 21 Rod 22 Piston 23 Pressure adjustment mechanism 23a Relief valve 24 Pilot valve 25 Shutoff valve 3 Pressure sensor 4 Pressure extraction Mechanism 41 High pressure air extraction member 42 Air hose 5 Cable 6 Controller

Claims (1)

An air motor, a hydraulic striking torque generator that is driven by the air motor and applies striking torque to the output shaft, and an operation stopping mechanism that senses that the screw tightening torque has reached a predetermined value and stops the operation of the wrench. In a torque tightening wrench management device comprising a torque control wrench, a high-pressure air take-out member for operating the air motor is provided on the back side of the shut-off valve, and the air motor is provided via the take-out member and the air hose. The high-pressure air that operates is pulled out to the outside of the torque control wrench, and the pressure of the high-pressure air at the supply position to the air motor generated at the end of the air hose corresponding to the striking torque of the hydraulic striking torque generator is detected A pressure sensor is provided. Detecting a change in the pressure of the high pressure air, via a cable to convert a change in pressure of the high pressure air detected into electrical signals, as well as transmitted to the controller that manages the screw tightening operation provided separately from the torque control wrench, The controller for screw tightening work in a torque control wrench, characterized in that in the controller, the number of occurrences of impact torque is measured from the change in pressure of the high-pressure air.

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