JP5367500B2 - Torque Wrench - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semi-automatic torque wrench capable of preventing double tightening and preventing tightening of a complete signal from being output accidentally. <P>SOLUTION: In a normal screw-tightening process, a member to be tightened, such as a bolt, is tightened to a temporarily tightening torque value by an electric motor; thereafter, it is tightened by a manual operation by means of a torque wrench body; and a toggle activation detecting switch activates to output the tightening complete signal from a drive control circuit, when a toggle mechanism activates, if the power supply current of the motor corresponding to the temporarily tightening torque value is detected within a double tightening monitor time which is specified until the temporary tightening torque value is reached, after a start current mask time specified when starting the motor is elapsed, it is determined as being a double tightening and the electric motor is stopped. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a semi-automatic torque wrench that temporarily tightens a fastening body such as a bolt or a nut to a certain torque value by electric drive and then manually tightens to a target torque value.

  As a semi-automatic torque wrench, a configuration using a brushless motor as a drive source has been proposed (Patent Document 1).

  A torque wrench described in Patent Document 1 is a manually operated torque wrench main body, a head portion that is swingably connected to the torque wrench main body, and is fixed via a toggle mechanism, and the head portion. An electric drive unit composed of a brushless motor and a speed reducer attached in a cantilever support state, and a drive shaft with a ratchet mechanism provided in the head unit by the driving force of the electric drive unit, A bolt is tightened by, for example, a socket attached to the drive shaft. The torque wrench main body is rotatably attached to the distal end portion of a handle portion formed in a tube shape, and the insertion end portion of the head portion inserted into the handle portion and the handle portion are connected by the toggle mechanism. It is connected.

  The toggle mechanism includes a moving body that is spring-biased to the head portion side by a spring member disposed in the handle portion, and a link member that is coupled between the insertion end of the head. The state in which the handle is inclined with respect to the axial direction is set as a toggle non-operating state, and the movable head is fixed in a non-swingable state with respect to the handle portion, and is integrated with the handle portion.

  In addition, a moving pin that stands through the long hole formed in the handle portion or faces the long hole is erected at the rear end portion of the head portion. For example, a micro switch fixed to the handle portion by the moving pin or the like The toggle operation detection switch is directly operated to detect the toggle operation electrically.

  On the other hand, the current consumption of the brushless motor increases as the load increases due to the tightening of the bolts. Therefore, the temporary fastening current value is set in advance corresponding to the temporary fastening torque value smaller than the set torque value. Then, after temporarily tightening to stop energizing the brushless motor when the temporary tightening current value is detected, the handle portion is pulled (rotated) manually to increase the tightening force and set by the spring force of the spring member When the set torque value is reached, the movable body moves backward against the spring force of the spring member via the link member, and toggle operation is performed, and the movable head is fixed to the handle portion. Is released and swings. As a result, the operator can confirm that the bolt has been tightened to the set torque value.

JP 2009-095961 A

  For example, when multiple bolts are tightened with the same tightening torque using a semi-automatic torque wrench that uses the brushless motor as a drive source, the bolts that have already been tightened are erroneously tightened again. Then, before reaching the set torque value, the temporary tightening current value is detected, and then tightening is performed twice by performing manual tightening, and the toggle operation detection switch outputs an ON signal.

  The number of bolts to be tightened is counted using the ON signal from the toggle operation detection switch. For example, when a plurality of bolts are tightened at one place, the bolts are tightened when the number of bolts to be tightened is reached. In the configuration where it is determined that the bolts have been tightened twice as described above, it may be determined that the tightening of all the bolts has been completed even though all the bolts are not actually tightened. There is.

  An object of the present invention is to solve such a problem, and even if the fastening operation is erroneously performed, the drive of the electric motor is immediately stopped and the toggle operation switch is turned on. It is intended to provide a torque wrench that can be prevented.

The structure of the torque wrench that achieves the object of the present invention includes a manually operated torque wrench main body, a swingable connection to the torque wrench main body, and a fixed through a toggle mechanism, and a connection to a fastening body. A head portion, an electric motor provided in the head portion, a start switch for driving the electric motor, a toggle operation detection switch for detecting the operation of the toggle mechanism, and the electric drive driven by turning on the start switch. A drive control circuit that stops the electric motor when the energizing current of the motor reaches a preset temporary tightening torque value, and then outputs a tightening completion signal when the toggle operation detection switch is turned on, and the drive control circuit Is set after the start-up current mask time set at the start-up of the electric motor has elapsed until the temporary tightening torque value is reached. Upon detection of the conduction current of the motor, wherein corresponding to the initial tightening torque value in twice clamping monitoring time is determined twice tightened to stop the electric motor, when it is determined that the twice fastening, abnormality notification for notifying the abnormality The abnormality notification means includes a light source disposed in an outer case having a mountain-shaped top portion that houses the electric motor, a slit formed in the mountain-shaped top portion of the case, and a light diffusivity attached to the slit. the and a lighting plate having, by illuminating the illumination plate by the light source, it characterized that you illuminate the two inclined surfaces and the top and the boundary of該山shaped top.

  According to the present invention, since a fastening body such as a bolt that has already been tightened is not erroneously tightened by driving the electric motor, it is possible to prevent a tightening completion signal from being output. For this reason, when counting, for example, the number of bolts that have been tightened each time a tightening completion signal is output, there is no erroneous count.

Further , it is possible to inform the operator that the fastening is performed twice by driving a light source such as an LED.

Furthermore , for example, blinking of an LED informing that it is tightening at least twice from both sides of the mountain-shaped slope can be visually recognized.

FIG. 1 is a drive control circuit diagram showing an embodiment of a semi-automatic torque wrench according to the present invention using a brushless motor as a drive source. In the timing chart of the drive control circuit of FIG. 1, (a) shows a normal screw tightening operation, and (b) shows a double screw tightening operation. 2 is a flowchart showing the operation of the drive control circuit shown in FIG. FIG. 2 is an external view of a semi-automatic torque wrench including the drive control circuit of FIG. 1, (a) is a top view, (b) is a front view, (c) is a bottom view, and (d) is a left side view of (b). (E) is a right side view of (b). (A) is a top view of the torque wrench body showing the positional relationship between the toggle operation detection switch and the torque wrench body, (b) is a front view of (a), and (c) is an illumination provided on the exterior case of the electric drive device. It is sectional drawing of a type | formula display apparatus. FIG. 6 is a diagram illustrating a plug shape into which a power supply / signal output cord in which power supply and signal output cables are combined is inserted into a connector provided in a case of the electric drive device illustrated in FIGS. 4 and 5; b) is a straight plug, and (c) and (d) are L-shaped plugs. It is a figure which shows the code | cord | chord provided with the L-shaped plug.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

  1 to 7 show an embodiment of a semi-automatic torque wrench according to the present invention. 1 is a drive control circuit diagram of a semi-automatic torque wrench using a brushless motor as a drive source, FIG. 2 is a timing chart of the drive control circuit of FIG. 1, (a) is a normal screw tightening operation, and (b) is tightened twice. The screw tightening operation is shown. FIG. 3 is a flowchart showing the operation of the drive control circuit shown in FIG. 4 is an external view of a semi-automatic torque wrench provided with the drive control circuit of FIG. 1, (a) is a top view, (b) is a front view, (c) is a bottom view, and (d) is a view of (b). Left side view, (e) is a right side view of (b). 5A is a top view of the torque wrench body showing the positional relationship between the toggle operation detection switch and the torque wrench body, FIG. 5B is a front view of FIG. 5A, and FIG. It is sectional drawing of the illuminated display apparatus. FIG. 6 is a diagram showing a plug shape into which a power supply / signal output cord into which a power supply cable and a signal output cable are combined is inserted into a connector provided in the case of the electric drive device shown in FIGS. a) and (b) are straight plugs, and (c) and (d) are L-shaped plugs. FIG. 7 shows a cord provided with an L-shaped plug.

First, the structure of the semi-automatic torque wrench according to this embodiment will be described below with reference to FIGS.
The torque wrench 20 is attached to the head portion 22, a torque wrench body 21 that is manually operated by an operator, a head portion 22 that is swingably connected to the torque wrench body 21 via a support shaft 21 a, and the head portion 22. A brushless motor, which is an electric motor, and an electric drive device 23 having a motor drive control circuit (see FIG. 1), a commercial power supply (for example, AC100V) is used as a drive power supply, and a power / signal output code 24 is the motor drive control circuit. It is connected to the.

  Moreover, the head part 22 and the torque wrench main body 21 are connected via a toggle mechanism (not shown). That is, since the head portion 22 and the torque wrench main body 21 are relatively rotatable with the support shaft 21a as a fulcrum, the electric drive device 23 connected to the head portion 22 is in a cantilevered support state with respect to the head portion 22. The handle portion 21b of the torque wrench body 21 is not restrained.

  The electric drive device 23 accommodates the constituent members of the electric drive device 23 in the outer case 23a, and transmits the rotation of the brushless motor to an output shaft (not shown) of the head portion 22 via a reduction gear (not shown). An angular shaft portion 22a formed on the angular shaft that forms the distal end portion of the output shaft protrudes outward from the main body portion 22b of the head portion 22, and a socket (not shown) is detachably mounted on the angular shaft portion 22a. . When the trigger 25 is pulled with a finger while the socket is fitted to a fastening body such as a bolt, screw or nut, the main power switch (start switch) 2 is turned on, the brushless motor is activated, and the fastening body is moved. Tighten. The output shaft of the head unit 22 rotates only in one direction by a ratchet mechanism (not shown).

  When the fastening body is temporarily tightened by the rotation of the brushless motor, the driving of the brushless motor is stopped. When the operator pulls the grip part 21c at the rear end of the handle part 21b constituting the torque wrench body 21 with his / her hand, the fastening body is further tightened, and when the set torque value is reached, the toggle mechanism is actuated to tighten. Complete.

  The toggle mechanism is connected between a moving body (not shown) that is spring-biased toward the head portion 22 by a spring member (not shown) disposed in the handle portion 21b, and the rear end portion of the head portion 22. A link member (not shown) that is tilted with respect to the axial direction of the handle portion 21b, and the head portion 22 is not allowed to swing relative to the handle portion 21b. And is integrated with the handle portion 21b.

  When the grip portion 21c of the handle portion 21b is gripped, the link is pulled (rotated) by manual operation to increase the tightening force, and when the set torque value set by the spring force of the spring member is reached, the link Through the member, the moving body moves backward against the spring force of the spring member to perform a toggle operation, and the head portion 22 is released from the fixed state with respect to the handle portion 21b and swings. As a result, the operator can confirm that the bolt has been tightened to the set torque value.

  In the present embodiment, the base member 23b of the electric drive device 23 is supported in a cantilevered state with respect to the head portion 22, and the base member 23b is spaced apart above the handle portion 21b. And the toggle action detection switch 11 which consists of a micro switch is attached to the lower surface of the base member 23b. Further, on the outer surface side of the handle portion 21b facing the toggle operation detection switch 11, a switch operation pin 21d is erected so as to face the toggle operation detection switch 11, and the head portion 22 and the handle portion 21b are relatively rotated. At this time, the engagement of the switch operation pin 21d and the switch operation piece 11a of the toggle operation detection switch 11 turns on the toggle operation detection switch 11 and outputs a tightening completion signal.

  That is, in the present embodiment, utilizing the fact that the electric drive device 23 rotates relative to the handle portion 21b, the toggle operation detection switch 11 is provided on the electric drive device 23 side, and the switch operation provided on the handle portion 21b side. Since the switch operation piece 11a of the toggle operation detection switch 11 is moved by the pin 21d so that the toggle operation detection switch 11 is turned on, a long hole is provided in the handle portion 21b and is erected at the rear end portion of the head portion 22. It is not necessary to penetrate the switch operating pin, and the number of processing of the handle portion 21b can be reduced. When the toggle operation detection switch 11 is attached to the handle portion 21b separately from the electric drive device 23, a signal output cable needs to be externally wired for electrical connection between the toggle operation detection switch 11 and the electric drive device 23. However, in the present embodiment, such external wiring is not necessary.

  Further, as shown in FIG. 5C, the electric drive device 23 is attached to, for example, red, blue, and green LEDs 31 in one place on the wiring board 30 disposed in the exterior case 23 a, and the LEDs 31 are turned on. By flashing, the automatic tightening state until the temporary tightening, the manual tightening state from the completion of the temporary tightening to the completion of the final tightening, and the abnormal state are notified.

  The outer case 23a has an upper surface formed in a shape of a cross section, and a slit 32 is provided in a portion that is connected to both slopes with the top portion interposed therebetween. The slit 32 is light transmissive and light diffusing. A plate 33 is attached. The LED 31 is disposed below the illumination plate 33.

  Since the lighting plate 33 is formed in a mountain shape, it can be seen from both the upper surface and the left and right sides, and the current tightening state can be maintained regardless of the work posture at the time of tightening bolts and the torque wrench. It becomes possible to confirm. In particular, the illuminating plate 33 has light diffusibility, and the LED 31 that is a light source is arranged at the center in the longitudinal direction of the illuminating plate 33 so that it can be seen toward the LED 31 even when viewed from various angles.

  A connector 34 is attached upward on the upper surface of the rear end portion of the outer case 23a, and a connector for connecting the power / signal output cord 24 is connected to the connector 34.

  In the present embodiment, one connector 34 can supply power to the electric drive device 23 and output various signals from the electric drive device 23, and a single power source can be supplied from the electric drive device 23 of a semi-automatic torque wrench. -Only the signal output cord 24 is drawn out so as not to interfere with the tightening work of bolts or the like.

  Examples of the plug structure of the power / signal output cord 24 connected to the connector 34 include the straight plug shape shown in FIGS. 6A and 6B and the L-shaped plug shape shown in FIGS. 6C and 6D. it can. The semi-automatic torque wrench of the present embodiment is generally used by suspending with a wire or the like. Therefore, when the power / signal output cord 24 is suspended from above, the straight plug shown in FIGS. 6A and 6B can be used. . If the power / signal output cord 24 cannot be suspended from directly above, an L-shaped plug shown in FIGS. 6C and 6D can be used.

  FIG. 7 shows the power / signal output cord 24 of the L-shaped plug. For example, the curled cord 24b connected to the L-shaped connector 24a is connected to the power cord 24c connected to the power plug 24d and the relay connector 24f. The signal output cables 24e are integrated into a single cord. The branching section 24g branches to the power cord 24c and the signal output cable 24e. Therefore, since the two cords are not separately connected to the semi-automatic torque wrench, it is possible to reduce the troublesomeness of the cord wrapping around the operator's arm or the like during the tightening operation. Moreover, since it has the curl cord 24b having elasticity, it does not get in the way during work compared to a straight cable.

  The relay connector 24f is connected via a relay connector 40a to a signal output cable 40 that is wired in advance and connected to a counter device (not shown), a sequencer, a count checker, and the like.

  Next, the motor drive control circuit will be described with reference to FIG.

  In FIG. 1, the motor drive control circuit of the present embodiment controls the brushless motor 12 by an AC 100V power source 1 that is a drive power source, and includes a drive circuit unit 5 and a CPU that controls the drive circuit unit 5. It has the control circuit part 10, the diode bridge circuit 3, the line filter 4, and the alerting | reporting part 6 using LED.

  The notification unit 6 lights up a green LED 31G displaying green when the start switch 2 is turned ON, a blue LED 31B displaying blue light for notifying the completion of temporary tightening and displaying the completion of final tightening, and an abnormal state. The notification unit 6 composed of a red LED 31R for displaying red, the first variable resistor 7a for adjusting the stop current for changing the stop current of the motor 12 in temporary fastening, and the rotation speed of the motor 12 are changed. Adjustment circuit section 7 constituted by a second variable resistor 7b for setting the motor rotation speed, a shunt resistor 8 for detecting an energization current of the motor 12, a start switch 2, and a toggle operation detection switch 11 And a start detection circuit 9 composed of a voltage dividing resistor or the like for detecting on / off of the start switch 2 and an example of obtaining a necessary voltage by dropping the voltage with a resistor or the like The first power supply portion 13a of the 12V power supply, the second power supply portion 13b of the 5V power supply for driving the power lamp 17, and a step-down power supply part 13 and a third power supply unit 13c of the 3.3V power supply. Reference numeral 17 is a power lamp, and 18 is a thermistor (PTC).

  In addition, the motor drive control circuit of the present embodiment has an interface 14 for outputting a tightening completion output signal to an external processing device by wire, and is driven by power supply from the first power supply unit 13a. The third power supply unit 13 is a power supply when an interface 15 for wirelessly outputting a tightening completion output signal to an external processing device is attached. In addition to the wireless interface 15, a tightening counter 16 Can also be attached.

  The drive circuit unit 5 shows switching elements 5a, 5b, 5c, 5d, 5e, and 5f made of transistors (FETs) and a switching element driver 5A (provided with drivers for W, U, and V phases, respectively). A known circuit configuration for driving the brushless motor 12 connected as described above is employed. Hall elements 12d, 12e, and 12f that detect the position of the magnet rotor are arranged at predetermined intervals in the brushless motor 12, and the control circuit 10 including the CPU supplies the switching element driver 5A based on the detection signals from these hall elements. Driving, the switching elements 5a, 5b, 5c, 5d, 5e, and 5f are on / off controlled, and the brushless motor 12 is rotationally controlled by selectively energizing the windings 12a, 12b, and 12c of the brushless motor 12. .

  In this embodiment, the power supply cord 24c of the power supply / signal output cord 24 and the diode bridge 3 are directly connected, and the control circuit section 10 is activated when the power supply cord 24c is connected to the drive power supply 1.

  The start switch 2 is connected in series between the diode bridge 3 and the drive circuit unit 5.

  Hereinafter, the configuration and operation of the control circuit unit 10 will be described with reference to FIGS. 1, 2, and 3.

  First, the case of the normal screw tightening operation shown in FIG.

  When the closing signal detected by the start detection circuit 9 is input to the start command unit 10d when the start switch 2 is turned on, the control circuit unit 10 starts driving the drive circuit unit 5 from the 6-phase PWM output unit 10b to the driver 5A. Give instructions. At that time, detection signals from the Hall elements 12d, 12e, and 12f of the brushless motor 12 are input to the Hall element signal input position detection unit 10c, and based on the position information of the magnet rotor from the Hall element signal input position detection unit 10c. The 6-phase PWM output unit 10b is controlled.

  Further, the control circuit 10 detects the motor energization current converted into a voltage by the current detection unit 10a via the shunt resistor 8.

  The brushless motor 12 starts rotating slightly after the start switch 2 is turned on (motor rotation delay time T1). That is, when the start switch 2 is turned on, the drive circuit unit 5 has not received an operation start instruction from the control circuit unit 10, so that no current flows through the drive circuit unit 5 and the brushless motor 12 has not yet rotated. Then, after the control circuit unit 10 receives an on (closed) signal from the start detection circuit 9, the start command unit 10d outputs a drive start signal to the switching element driver 5A, and a current flows through the drive circuit unit 5 to cause a brushless motor. 12 rotates. Therefore, since the motor drive current flows to the start switch 2 after the contact of the start switch 2 is closed, no arc is generated at the contact of the start switch 2.

  In the control circuit unit 10, the lamp control unit 10e turns on the green LED 31G in response to a start command from the start command unit 10d.

  When the brushless motor 12 is activated, a large activation current flows during a short time (activation current masking time) T2 at the beginning of activation, and this current is detected by the current detection unit 10a. And when starting current mask time T2 passes, motor energization current will become small. In the present embodiment, the twice tightening monitoring time (timer) T3 is started after the drive current mask time T2 has elapsed.

  Automatic tightening of the screw by the brushless motor 12 is started, the load resistance of the motor 12 is increased by tightening the screw, the energizing current is increased, and the energizing current (voltage) detected by the current detecting unit 10 is the temporary tightening torque setting unit. If it is determined that the temporary fastening completion voltage, which is the target stop current set in 10h, has been reached, the motor is automatically stopped and the blue LED 31B blinks to notify the completion of temporary fastening, and the operator is prompted to perform final fastening manually. I am doing so.

  The twice tightening monitoring timer T3 ends before reaching the temporary tightening completion. The control circuit unit 10 adjusts the rotation speed of the brushless motor 12 set by the speed setting unit 10 so that the temporary tightening is not completed before the timer time of the second tightening monitoring timer T3 ends. Can do.

  After the completion of the temporary tightening, the operator removes the finger from the trigger 25 to turn off the start switch 2, or presses the trigger 25 as it is to manually close the start switch 2 and perform the final tightening manually. When the mechanism is activated, the toggle operation detection switch 11 is turned on, and when a tightening completion signal is input to the tightening completion input unit 10f, the lamp control unit 10e switches the blue LED 31B from blinking to lighting and notifies the completion of the final tightening. Then, the completion signal output control unit 10 i outputs a tightening completion signal to the signal output cable 24 e via the interface 14. The processing apparatus to which the tightening completion signal is input via the signal output cable 24e adds 1 to the tightening number counter. The drive control device 23 may be provided with a tightening counter and a display unit made of liquid crystal or the like to display the tightening completion number and the set number.

  When the final tightening is completed and the start switch 2 is turned off, the LED 31 remains held, and the operator can check the state even after the start switch 2 is turned off. When the start switch 2 is turned on at the start of the next tightening, all the LEDs 31 are turned off and the tightening is started.

  Next, the twice tightening screw tightening operation shown in FIG.

  As in the case shown in FIG. 2A, the trigger 25 is pressed to turn on the start switch 2, the motor rotation delay time T1 and the starting current mask time T2 have elapsed, and the twice tightening monitoring timer T3 is started. When the bolt to be tightened has already been tightened, the motor current quickly reaches the stop target current for temporary tightening from the screw seat. For this reason, in the present embodiment, when the current detection unit 10a detects the stop target current indicating the completion of the temporary tightening before the end of the twice tightening monitoring timer T3, the driving of the brushless motor 12 is stopped and the red LED 31R blinks. Let the operator know that it is tightening twice.

  For this reason, the operator removes his / her finger from the trigger 25 without manually performing the final tightening operation, and turns off the start switch 2. Therefore, in the case of the second tightening, the toggle operation detection switch 11 is not turned ON, so that the tightening completion signal is not output from the completion signal output control unit 10i, and one is not added to the number of tightening by mistake.

  The normal screw tightening operation and the double screw tightening operation will be described based on the flowchart shown in FIG.

  (Step “abbreviated as S” 1): The start command unit 10d detects that the start switch 2 is turned on.

  S2: The motor rotation delay timer T1 is started.

  S3: With the start of motor rotation, the green LED 31G is turned on.

  S4: The current detector 10a detects the starting current and starts the starting current mask timer T2.

  S5: After the start-up current mask timer T2 ends, the twice tightening monitoring timer T3 is started.

  S6: It is determined whether or not the current detected by the current detection unit 10a has reached the target current corresponding to the completion of temporary fastening. When the target current is reached, the process proceeds to S7.

  S7: When the target current is reached within (inside) the set time (Tset) of the twice tightening monitoring timer T3 set for the twice tightening determination, it is determined that the tightening is twice, and the process proceeds to S12. Otherwise, it is determined that the screw tightening operation is normal, and the process proceeds to S8.

  S8: The control of the drive circuit 5 is stopped, and the process proceeds to S9 after waiting for the motor energization current detected by the current detection unit 10a to become 0 or less.

  S9: Upon completion of temporary fastening, the motor drive is stopped, the completion of temporary fastening is indicated, and the blue LED 31B that prompts final fastening is blinked.

  S10: It is determined whether or not the final tightening is completed. When the ON signal from the toggle operation detection switch 11 is input to the tightening completion input unit 10f, the process proceeds to S11.

  S11: A completion signal is output from the completion signal output control unit 10i, the blue LED 31B is turned on, and the process ends.

  On the other hand, if it is determined to tighten twice in S7, in S12, the motor is stopped, the red LED 31R is blinked, and the process ends.

  The start switch 2 is turned on in a state where the set torque value set in the torque wrench toggle mechanism is kept small and the temporary tightening torque value set in the control circuit 10 is set to a value larger than the set torque value. Then, the toggle mechanism is activated by driving the motor, and the toggle operation detection switch 11 is turned on. Even in such a case, if the tightening completion input unit 10f receives the tightening completion signal from the toggle operation detection switch 11 within the timer time of the twice tightening monitoring timer T3, it is determined that the operation is erroneous, and the completion signal output control unit The tightening completion signal may not be output from 10i. Of course, the same applies to the case where the fastening completion input unit 10f receives a fastening completion signal from the toggle operation detection switch 11 before detecting the completion of temporary fastening.

DESCRIPTION OF SYMBOLS 1 AC100V power supply 2 Start switch 3 Diode bridge 4 Line filter 5 Drive circuit part 5a-5f Switching element 5A Switching element driver 6 Notification part 31G Green LED 31B Blue LED 31R Red LED
7a 1st variable resistor 7b 2nd variable resistor 8 Shunt resistor 9 Start detection circuit 10 Control circuit part (CPU)
10a Current detection unit 10b 6-phase PWM output unit 10c Hall element signal input position detection unit 10d Start command unit 10e Lamp control unit 10f Tightening completion input unit 10g Speed setting unit 10h Temporary tightening torque setting unit 10i Complete signal output control unit 11 Toggle operation Detection switch 11a Switch operation piece 12 Brushless motor 12a to 12c Winding of brushless motor 12d to 12f Hall element 20 Torque wrench 21 Torque wrench body 21a Support shaft 21b Handle portion 21c Grip portion 21d Switch operation pin
22 Head portion 22a Square shaft portion 22b Main body portion 23 Electric drive device 23a Exterior case 23b Base member 24 Power source / signal output cord 25 Trigger

Claims (1)

A manually operated torque wrench main body, a head portion connected to the torque wrench main body so as to be swingable and fixed via a toggle mechanism, and connected to a fastening body, and an electric motor provided on the head portion And a start switch for driving the electric motor, a toggle operation detecting switch for detecting the operation of the toggle mechanism, and an energization current of the electric motor driven by turning on the start switch to a preset temporary tightening torque value. A drive control circuit that stops the electric motor when reaching, and then outputs a tightening completion signal when the toggle operation detection switch is turned on,
The drive control circuit corresponds to the temporary tightening torque value within a twice tightening monitoring time set until the temporary tightening torque value is reached after elapse of the starting current mask time set when starting the electric motor. When the energizing current of the motor to be detected is detected, it is determined that the tightening is performed twice, and the electric motor is stopped, and when it is determined that the tightening is performed twice, an abnormality notifying unit that notifies an abnormality is driven, A light source disposed in an outer case having a mountain-shaped top portion for storing, a slit formed in the mountain-shaped top portion of the case, and an illumination plate having a light diffusivity attached to the slit, and the light source by illuminating the illumination plate, torque wrench characterized that you illuminate the two inclined surfaces and the top and the boundary of該山shaped top.

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