JP2016059997A5 - - Google Patents

Description

In Figure 1, a torque wrench 1 has a tubular handle portion 2, a head unit 3 is tightening torque transmitting means for transmitting a tightening torque to the fastening member 6 such as a bolt, provided in the handle section 2 A torque limiter 4, a socket 5 that is attached to a square shaft 32 of the head portion 3 and is fitted to a fastening member 6 such as a bolt, a strain gauge 7 as a tightening force detection sensor that is attached to the head portion 3, And a data acquisition unit 8 having a data transmission function. The square shaft 32 is connected to the head unit 3 via a one-way rotation mechanism such as a ratchet.

When the fastening member 6 is fitted to the socket 5 and the handle portion 2 is gripped and turned in a predetermined direction, the fastening member 6 is tightened. When the set torque value is reached, the toggle 45 is moved relative to the axis. As a result, the spring seat 41 moves backward against the spring force of the torque value setting spring 42. As a result, transmission of the tightening force from the handle portion 2 to the head portion 3 is cut off. At this time, the handle portion 2 is rotated relative to the head portion 3 of the support shaft 21 as a fulcrum. A toggle operation detection pin (not shown) is attached to the rod portion 33 of the head portion 3 and passes through an opening (not shown) formed in the handle portion 2. A through end portion of the toggle operation detection pin operates a tightening completion detection switch (not shown) attached to a circuit board 81 to be described later.

In the present embodiment, the circuit board 81 is provided with a communication unit 86, an angular velocity sensor 87, a processor 80, and the like. As shown in FIG. 2, the processor 80, the torque value conversion unit 801 for acquiring the torque value from the detection signal of the strain gauge 7, and to that ANGLE conversion unit 802 acquires a rotation angle from the detection signal of the angular velocity sensor 87 , A double tightening determination unit 803 is provided. The angular velocity sensor 87 detects the rotation of the handle portion 2.

2, the processor 80, ROM 90, RAM 91, display unit 84, a communication unit 86, the angular velocity sensor 87, strain gauge 7 is connected via a bus 92.

The processor 80 includes a ROM 90 that stores a twice tightening determination program (shown in FIGS. 3 and 4) and a RAM 91 that provides the processor 80 with a temporary work area as memory units.

In the present embodiment, as shown in FIG. 3, the torque value obtained by converting a torque value conversion unit 801 is output to the communication unit 86 and the twice fastening determination unit 803. The double-tightening determination unit 803 performs double-tightening determination as to whether or not the fastening member has already been tightened based on the waveform of the acquired torque value (first mode). As shown in FIG. 4, the double-tightening determination unit 803 determines whether the fastening member has already been tightened based on the acquired torque value waveform and the angle information converted by the angle conversion unit 802. The second tightening determination is performed (second mode).

Generally, when fastening a fastening member such as a bolt to a member to be fastened, which is a cylinder block of an engine part, for example, the bolt is tightened to a certain fastening force (this fastening is referred to as temporary fastening), and after temporary fastening, using a torque wrench The fastening member is tightened (this tightening is referred to as main tightening). Then, in this clamping, by the torque value tightening reaches the set torque value, it is common practice to repeat several times the ratchet Tsu preparative operation.

In FIG. 3, a torque value exceeding a threshold value (peak hold torque) is acquired with the vertical axis representing the torque value and the horizontal axis representing time.

Thus, twice fastening determination unit 803, between the start tightening until engagement completion detection switch is ON, when detecting no ratcheting operation discriminates that the twice fastening, warning on the display unit 84 Display. Also, a warning is given by a buzzer sound.

Next, when the handle portion 2 is rotated in the tightening direction, a torque waveform B2 is obtained. The torque waveform B2 has a torque value larger than that of the torque waveform B1, but has not yet reached the set torque value. Therefore, once performed ratchet Tsu bets operation described above, to rotate the handle 2 in the tightening direction again. As shown in the torque waveform B3, the final tightening is completed by the third tightening. In the torque waveform B3, the fastening completion detection switch is turned on at the peak of the torque value.

The twice tightening determination unit 803 detects the ratchet operation during the period from the start of tightening until the tightening completion detection switch is turned on, so it is determined that the tightening is not performed twice, and the display unit 84 displays the tightening completion indication. Do.

Therefore, according to the present embodiment, it is possible to determine whether or not the torque wrench 1 itself is tightened twice.

In FIG. 4, a torque waveform C indicated by a broken line indicates a case where a fastening member such as a bolt that has been completely tightened with a set torque value is tightened by the torque wrench 1 of the present embodiment. Torque waveforms D1, D2, and D3 indicated by two-dot chain lines, and a torque waveform E indicated by a solid line indicate a state in which the fastening member that has been temporarily tightened is finally tightened by the torque wrench 1 of the present embodiment.

When the fastening member that has been completely tightened is tightened by the torque wrench 1 of the present embodiment, as shown by the waveform C, the handle portion 2 hardly rotates but the torque value increases rapidly. In this case, the specific angle representing the ratio of the screw rotation angle (θ) at the time of fastening of a fastening member such as a bolt to the screw fastening torque value (T) is Δθ1. When the set torque value is reached, the fastening completion detection switch is turned on.

That is, twice fastening determination unit 803, when determining the rotation angle and torque values than the ratio angle Δθ1 of the handle portion 2, also detects the ON of engagement completion detection switch determines that twice clamping, the display unit 84 in two Display the tightening. Also, warn twice with a buzzer.

On the other hand, the double-tightening determination unit 803 determines that the final tightening has been performed when the ratio angle Δθ2 is obtained from the rotation angle and torque value of the handle unit 2 and detects that the fastening completion detection switch is ON, and then fastens to the display unit 84. Display completion. Here, the ratio angle Δθ3, which is a threshold value for determining whether or not to tighten twice, is stored in the ROM 90 in advance.

Therefore, if calculated by the obtained ratio angle Δθn threshold and a ratio angle Δθ3 less is provisionally tightened by fastening members determined to have tightened, if it exceeds the ratio angle Δθ3 angle threshold and twice tightening Determine.

In the above-described embodiment, in the second mode, the ratio angle Δθ is compared with the angle threshold value to determine whether or not the tightening is performed twice, but the present invention is not limited to this. For example, as shown in FIG. 5, simply, from the start of angle measurement, initial tightening if the measured angle to the torque limiter of the torque wrench to operate (engagement completion detection switch is ON) Jer threshold angle super It determines that biasing, it is possible to determine that the detected twice fastening is less than the threshold angle. In this case, the torque limiter is actuated (the fastening completion detection switch is ON), and the first tightening is performed when the measurement angle is 35 degrees, and the second tightening is performed when the measurement angle is 2.5 degrees. Therefore, it is possible to determine whether or not to tighten twice based on the measurement angle by appropriately setting the threshold angle.

DESCRIPTION OF SYMBOLS 1 Torque wrench 2 Handle part 21 Support shaft 3 Head part 31 Head main body part 32 Square axis 33 Rod part 4 Torque limiter 41 Spring seat 42 Torque value setting spring 43 Adjustment screw axis 44 Nut member 45 Toggle 5 Socket 6 Fastening member 7 Strain gauge 8 Data acquisition unit 80 Processor 801 Torque value conversion unit 802 Angle conversion unit 803 Double tightening determination unit 81 Circuit board 83 Exterior case 84 Display unit 85 86 Communication unit 87 Angular velocity sensor 90 ROM 91 RAM 92 Bus

Claims (4)

Tightening torque transmission means for transmitting the tightening torque to the fastening member via the one-way transmission mechanism;
A tightening torque measuring means for measuring a tightening torque value;
A torque limiter that operates when the tightening torque value reaches the set torque value;
Tightening completion detection means for detecting the operation of the torque limiter and outputting a tightening completion detection signal ;
Aforementioned tightening torque measuring means and the torque value tightening measured is said completion detection signal twice clamping discrimination information tightening, between the start tightening until obtaining a completion detection signal said clamping, the one-way transmission A double-tightening determining means for determining whether or not the double-tightening is performed depending on the presence or absence of the operation of the mechanism,
Tightening tool with   When the operation of the one-way transmission mechanism is detected, the double-tightening determination unit determines that a fastening member that has not yet been tightened is tightened, and if the operation of the one-way transmission mechanism is not detected, the tightening is already tightened. The tightening tool according to claim 1, wherein the tightening member is determined to be a second-time tightening in which the fastening member that has been completed is tightened again. The double-tightening determination means detects the operation of the one-way transmission mechanism when the measured tightening torque value does not reach the set torque value and increases after the tightening torque value decreases. The fastening tool according to claim 2 , wherein: The tightening tool, tightening tool according to any of claims 1 3, characterized in that the torque wrench or torque screwdriver.