Fastening tool

[Technical Field to which the Invention belongs] The present invention relates to an improvement of a tightening tool such as an impact wrench or an impact driver.

[Conventional Technique] An impact wrench, an impact driver, or the like is often used as a tightening tool for firmly tightening screws such as bolts and nuts. This type of tool includes, for example, a hammer that is rotated by a rotary drive source such as an electric motor or an air motor, and an anvil that engages with screws to rotate the screws. The hammer and the anvil collide with each other, and the hammer rotates the anvil. Then, when a force exceeding a predetermined value acts between the hammer and the anvil, the hammer is linked so as to idle with respect to the anvil. In order to provide such a configuration, the hammer continuously rotates the anvil and continuously tightens the screws while the screws are screwed with a light load. Then, when the screws are tightened and a force equal to or higher than a predetermined value acts between the anvil and the hammer, the hammer starts to idle, and after idling at a predetermined angle, collides with the anvil. By repeating the operation of idling and collision, the anvil rotates each time the hammer collides, and the screws are tightened each time.

[0003] In the case of such a tightening tool, the final tightening torque of the screw depends on the number of collisions. For this reason, techniques for adjusting the tightening torque have been conventionally developed (for example, Japanese Patent Application Laid-Open No. 5-200677). In the technique described in the above publication, a setting means for setting the number of collisions between the hammer and the anvil is provided, and when the hammer and the anvil collide with each other for the number of times set by the setting means, the rotation drive source is stopped, which is appropriate. Tighten the screw with the tightening torque.

[0004] [Problems to be Solved by the Invention] With the above-mentioned tightening tool, the tightening work can be appropriately performed by automatically adjusting the tightening torque, but the work other than the tightening work ( For example, when performing temporary tightening work, dismantling work, repair work, etc.), these work had to be performed depending on the experience and intuition of the operator who handles the tightening tool. Therefore, with the conventional tightening tool, it is not possible to efficiently perform the work other than the tightening work.

[0005] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to realize a tightening tool capable of efficiently performing each work performed by the tightening tool. ..

[Means, Actions and Effects for Solving the Problems] In order to solve the above problems, the tightening tool of the present invention is based on a hammer colliding with an anvil.<u style="single">What</u>Tightening tool to rotate the anvil<u style="single">And</u>, A rotary drive source that rotates the hammer,<u style="single">Times</u>Start the rolling drive source<u style="single">Su</u>Starting method and<u style="single">From the detection means for detecting the collision between the hammer and the anvil, and the mode group including the tightening work mode and the dismantling work mode.</u>Tightening tool work mode<u style="single">Select</u>Configuration<u style="single">Keep</u>Setting means and<u style="single">Ki</u>When the means of movement is activated<u style="single">Set up in</u>Constant means<u style="single">Set up in</u>Determined<u style="single">ing</u>Working mode<u style="single">In the following manner corresponding to</u>Operate the rolling drive source<u style="single">System</u>With means<u style="single">, The control means; when the tightening work mode is set, the rotation drive source is rotated forward, and when the dismantling work mode is set, the rotation drive source is rotated in the reverse direction, and the detection means is used. It is characterized in that the reverse rotation of the rotation drive source is stopped after a predetermined time after the collision is no longer detected.</u>.. With this tightening tool, the working mode of the tightening tool is<u style="single">As a setting means</u>The operation of the rotary drive source is controlled in the set and set working modes. Therefore,<u style="single">When performing work other than tightening work</u>Work can be done efficiently without relying on the experience and intuition of the handler.<u style="single">In particular, during dismantling work, nuts that are tightened to a predetermined torque must be loosened and removed from bolts and the like. If the timing to stop the rotary drive source is delayed during such dismantling work, the nuts may be loosened too much and the nuts may be completely removed from the bolts or the like, and the nuts may fall and be lost. .. When the dismantling work mode is set, this tightening tool rotates a predetermined time after the collision between the hammer and the anvil is no longer detected even if the starting means (for example, the main switch) is continuously operated. The drive source automatically shuts down. Therefore, the rotary drive source can be automatically stopped in a state (combined with the bolt) before the nuts are completely removed from the bolt or the like. Therefore, it is possible to prevent the nuts and bolts from being lost due to the nuts being completely detached from the bolts and the like, and the dismantling work can be efficiently performed.</u>【0007】<u style="single">During temporary tightening work (when you want to keep the bolts seated), you must tighten the nuts so that the tightening torque of the nuts does not become too large. However, if the timing for stopping the rotation of the rotary drive source is too late, the nuts will be in a state of being overtightened, and if it is too early, the nuts will be in a state of being too loose.</u><u style="single">Therefore, the above</u>For tightening tools<u style="single">The mode group includes a temporary tightening work mode, and when the temporary tightening work mode is set, the control means rotates the rotation drive source in the forward direction, and the detecting means detects the first collision. The forward rotation of the rotation drive source is stopped after a predetermined time has elapsed.</u>Is preferable.<u style="single">In this tightening tool, the rotary drive source is automatically stopped a predetermined time after the hammer and the anvil collide for the first time even if the starting means is continuously operated. Therefore, the temporary tightening work can be efficiently performed without relying on the experience and intuition of the operator.</u>【0008】<u style="single">If the tightening base metal is destroyed by a single collision between the hammer and the anvil, the tightening torque cannot be adjusted by managing the number of collisions between the hammer and the anvil. In such a case, it is conceivable to use the starting means as a switch and adjust the pulling allowance of the switch to reduce the rotation speed of the rotational drive source and adjust the tightening torque, but rely on the experience and intuition of the operator. Therefore, it becomes difficult to adjust the tightening torque appropriately.</u><u style="single">Therefore, the above</u>For tightening tools<u style="single">The mode group includes a tightening torque adjustment work mode, and the control means adjusts the rotation drive source to a predetermined rotation speed set in advance when the tightening torque adjustment work mode is set. And rotate forward</u>Is preferable.<u style="single">With this tightening tool, the tightening torque adjustment work can be appropriately performed by adjusting the rotation speed of the rotation drive source to a predetermined rotation speed set in advance.</u>BEST MODE FOR CARRYING OUT THE INVENTION Next, a tightening tool embodying the present invention will be described with reference to the drawings. FIG. 1 shows a partial cross-sectional side view of the impact wrench 1. Reference numeral 3 in the figure shows a housing in which the motor 22, which is a rotational drive source, is housed and fixed. A gear is formed on the output shaft 20 of the motor 22 (which is pivotally supported by the bearing 19), and a plurality of planetary gears 12 are meshed with this gear. The planetary gear 12 has a pin 14 as an axis, and the pin 14 is fixed to a spindle 8 pivotally supported by a bearing 23. Further, the planetary gear 12 is located on the inner diameter side of the internal gear 16 fixed to the internal gear case 18 and meshes with the internal gear 16. The reduction mechanism is composed of these gear trains. The spindle 8 fixing the pin 14 is rotationally driven by the motor 22. A plurality of grooves 8a are formed in a V shape on the spindle 8, and a hammer 4 can idle on the spindle 8. A ball 6 is interposed between the hammer 4 and the groove 8a. The cam mechanism is composed of the groove 8a and the ball 6, and the hammer 4 can move relative to the spindle 8 along the groove 8a. Further, a spring 10 is housed between the hammer 4 and the spindle 8 in a compressed state via a ball 51 and a washer 49, and the hammer 4 is always urged to the right in the drawing. Anvil 2 is rotatably attached to the housing 3 on the tip side of the hammer 4. The tip 2a of the anvil 2 has a polygonal cross section, to which a box (not shown) that engages with the heads of nuts is attached. A pair of ridges 2b and 2c extending in the radial direction are formed on the rear end surface of the anvil 2. In addition, ridges 4b and 4c extending in the radial direction are also formed on the tip surface of the hammer 4, so that the side surfaces of the ridges 2b and 2c and 4b and 4c come into contact with each other.

[0010] When the nuts are tightened with a light load in the tightening mechanism described above, the force acting between the ridges of the anvil 2 and the hammer 4, that is, the force acting between the spindle 8 and the hammer 4 via the ball 6. The force to do is also weak, and the hammer 4 is pressed against the anvil 2 side by the force of the spring 10. Therefore, the rotation of the spindle 8 is continuously transmitted to the hammer 4 and the anvil 2, and the nuts (not shown) are continuously tightened. On the other hand, when the tightening force of the nuts becomes large, a large force also acts between the ridges of the anvil 2 and the hammer 4, and a large force also acts between the spindle 8 and the hammer 4 via the ball 6. Will be. Therefore, the force for moving the hammer 4 to the rear side of the spindle 8 along the groove 8a also increases. That is, when a force exceeding a predetermined value acts between the anvil 2 and the hammer 4, the hammer 4 retracts and the contact relationship between the ridges 2b and 2c and the ridges 4b and 4c is lost, and the hammer 4 with respect to the anvil 2. Idle around. When the ridges 4b and 4c exceed the ridges 2b and 2c, the spring 10 advances the hammer 4. Therefore, the hammer 4 collides with the anvil 2 after swinging at a predetermined angle. This phenomenon of idling and collision is repeated, and the nuts are tightened more firmly at each collision.

[0011] Next, various switches provided on the handle portion 3a will be described. The handle portion 3a is provided with a main switch 48 for activating the motor 22 which is a rotation drive source and a forward / reverse changeover switch 24 for switching the rotation direction of the motor 22. Further, a dial setting unit 34 is provided at the lower end of the handle unit 3a. The dial setting unit 34 is an enlarged view of FIG. 2 in which the battery pack 122 is removed from the tightening tool 1 and viewed from the direction II in FIG. 1 (from the lower side of the tightening tool 1) and the dial setting unit 34 in FIG. As shown in FIG. 3, a first setting dial 33 and a second setting dial 35 are provided. As shown in FIG. 3, in the present embodiment, the first setting dial 33 is provided with a number scale of 0 to 9 and an alphabet scale of A to F. The second setting dial 35 is provided with a scale of only numbers 0 to 9. Therefore, in this embodiment, 160 kinds of combinations from "00" to "F9" can be set. An adjustment groove 34a is provided on each of the dials 33 and 35, and the tip of a flat-blade screwdriver is inserted into the adjustment groove 34a to set each dial to a predetermined scale. As is clear from FIG. 1, the dial setting unit 34 described above has a structure in which the settings of the dials 33 and 35 can be changed only when the battery pack 122 is removed. This is to prevent unintentional setting changes by the user. Further, as shown in FIG. 2, a contactor 42 is provided at the lower end of the housing 3, and the contactor 42 is brought into contact with a contactor (not shown) of the battery pack 122.

[0012] As shown in FIG. 1, a control board 36 is attached to a position in the handle portion 3a from the lower end, and electronic components such as a microcomputer 38 and a relay 40 are mounted therein. Further, the control board 36 incorporates a sound receiving unit 30 (piezoelectric buzzer or the like) that receives the collision sound of the hammer 4 and the anvil 2.

Next, the circuit configuration of the final tightening tool 1 will be described with reference to FIG. The microcomputer 38 mounted on the control board 36 is a microcomputer in which the CPU 110, ROM 118, RAM 120 and I / O 108 are integrated into one chip, and is connected as shown in FIG. A control program for controlling the operation of the motor 22 and the sound receiving unit 30 is stored in the ROM 118 of the microcomputer 38. The sound receiving unit 30 is connected to one terminal of the comparator 104 via the filter 102. The voltage V3 of the reference voltage generator 112 is input to the other terminal of the comparator 104. The output voltage of the comparator 104 is input to the microcomputer 38. The battery pack 122, which is a power source, is connected to the motor 22 via a main switch 48, a forward / reverse changeover switch 24, and a switching element 40. The switching element 40 is connected to the microcomputer 38 via the switching circuit 114. The dial setting unit 34 is also connected to the microcomputer 38.

[0014] In the circuit described above, when the hammer 4 collides with the anvil 2 due to the rotation of the motor 22 and a collision sound is generated, the voltage V1 is generated from the sound receiving unit 30. This voltage V1 is a combination of high-frequency and low-frequency noise (motor noise, etc.) and pulse waves corresponding to collision noise. The low frequency noise of this voltage V1 is removed by the filter 102, becomes the voltage V2, and is output from the filter 102. The comparator 104 turns on from off when the filter voltage V2 becomes higher than the other comparison voltage V3. Each pulse wave V5 rises at the time of the collision between the hammer 4 and the anvil 2, and corresponds to the collision sound. Therefore, the microcomputer 38 counts the number of collisions by counting the pulse wave V5. The reference voltage V3 of the comparator 104 is set to the noise level or higher.

Next, the operation of the tightening tool configured as described above will be described. In the tightening tool according to the present embodiment, the motor 22 and the sound receiving unit 30 are controlled for each mode set by the dial setting unit 34. Hereinafter, the operation of the tightening tool for each mode will be described. (1) Collision Count Setting Mode (Tightening Work Mode) In the tightening tool of this embodiment, when the first setting dial 33 of the dial setting unit 34 is set to the scale of numbers 0 to 9 (No. 1). 2 The setting dial 35 can be any of 0 to 9), and the number of collisions between the hammer 4 and the anvil 2 is set by the dial setting unit 34. The processing performed by the microcomputer 38 at this time will be described. This process is executed while the main switch 48 is being operated, the execution is stopped when the main switch 48 is turned off, and the execution is restarted when the main switch 48 is operated again. First, when the main switch 48 is turned on, the number "xy" set in the dial setting unit 34 (the number scale set in the first setting dial is x, and the number scale set in the second setting dial is x). Is read and stored in RAM120 as a variable xy. Next, it is determined whether or not the value set in the dial setting unit 34 is "00". When "00" is set in the dial setting unit 34 (I mode), the number of collisions is set to 0, and the main switch 48 is set regardless of whether the forward / reverse changeover switch 24 is in the forward / reverse position or in the reverse position. The motor 22 does not rotate even if it is operated. This "00" (I mode) can be used to easily check whether the dial setting unit 34 is broken.

[0016] If the set value of the dial setting unit 34 is not "00", it is determined whether or not "99" is set next. Here, "99" is a maximum value that can be set when only the number scale of the dial setting unit 34 is used, and if this maximum value is set, the switching element 40 is turned on. That is, when "99" is set (III mode), the motor 22 continues to rotate while the main switch 48 is turned on. In this III mode, the "hit count auto stop function" described later does not operate regardless of whether the forward / reverse changeover switch 24 is in the forward / reverse position. This "99" (III mode) is particularly effective for tightening work when it is not necessary to manage the tightening torque.

When neither "00" nor "99" is set, that is, when "01" to "98" are set in the dial setting unit 34 (II mode), then the forward / reverse changeover switch 24 is used. , The microcomputer 38 determines whether the forward rotation is set or the reverse rotation is set. This is determined by discriminating the potential of one of the lead wires between the forward / reverse changeover switch 24 and the switching element 40 as shown in FIG. This potential changes depending on the forward / reverse of the forward / reverse changeover switch 24. When reverse rotation is selected by setting the forward / reverse changeover switch 24 to the reverse position, the motor 22 is rotated while the main switch 48 is turned on. That is, in the case of reverse rotation, the motor 22 is continuously rotated until the main switch 48 is turned off.

When forward rotation is set, the expected number of collisions z (stored in RAM 120) is calculated from the number "xy" set in the dial setting unit 34, and the hammer 4 and the anvil are calculated by the expected number of collisions z. 2 collides and the motor 22 is stopped. The expected number of collisions z is calculated by the following formula. z = (x × 10 + y) × 2 + 1 That is, 50 is set on the dial setting unit 34 (the first setting dial 33 is set to 5 and the second setting dial 35 is set to the scale of 0). When is set, the expected number of collisions z is 101. The function of stopping the motor 22 at the set number of scheduled collisions is called the blow count auto stop function. In this case, first, the switching element 40 is turned on, the motor 22 is started to rotate, and the number of pulse waves (number of collisions) is counted by the microcomputer 38. The motor 22 is stopped when the number of this pulse wave reaches the scheduled number of hits z (blow count auto stop function). In this way, in the II mode, the tightening work for managing the tightening torque can be performed.

[0019] The case where the number scales of "0" to "9" are selected on the first setting dial 33 (collision number setting mode) has been described above. Hereinafter, the operation when the alphabet scales "A" to "F" are selected on the first setting dial 33 will be described. When "A" is set on the first setting dial 33 (the second setting dial 35 can be any of 0 to 9), when the forward / reverse changeover switch 24 is in the forward / reverse position or in the reverse position. However, even if the main switch 48 is turned on, the motor 22 which is the rotation drive source does not rotate. That is, the "A" scale is a scale provided to prevent unintended malfunction of the user, and is a scale corresponding to the special work mode described below, and the number scale which is the collision number setting mode. Prevents accidental setting of "9".

(2) Temporary tightening work mode When "B" is set on the first setting dial 33 (IV mode), the temporary tightening work is performed. That is, during the temporary tightening operation, the nuts must be tightened without increasing the tightening torque of the nuts. However, if the timing for stopping the rotation of the motor 22 is too late, the nuts will be in a state of being overtightened, and if it is too early, the nuts will be in a state of being too loose. Therefore, in the present embodiment, the tightening tool is operated in the temporary tightening work mode by setting "B" on the first setting dial 33. That is, when the forward / reverse changeover switch 24 is in the forward / reverse position, the motor 22 is rotated by the on operation of the main switch 48, and a predetermined time after the sound receiving unit 30 detects the first collision between the hammer 4 and the anvil 2. The motor is programmed to stop. This predetermined time is determined by the number "n" of the second setting dial 35, and specifically, "n" x 0.1 seconds. For example, when "2" is set on the second setting dial 35, the motor 22 stops after 0.2 seconds. Specifically, the microcomputer 38 first stores the time set by the number on the second setting dial 35 in the RAM 120. Then, after determining that the pulse wave from the comparator 104 has been received, the motor 22 is rotated for the time stored in the RAM 120, and the switching element 40 is turned off. In this way, according to the IV mode, even if the operator keeps the main switch 48 on all the time, the motor 22 automatically stops a predetermined time after the hammer 4 and the anvil 2 collide for the first time. Therefore, the temporary tightening work (when the bolt is only seated) can be efficiently performed. When the forward / reverse changeover switch 24 is in the reverse position, the motor 22 is started by turning on the main switch 48, and the motor 22 is continuously rotated until the main switch 48 is turned off (the striking count auto stop function is stopped).

(3) Dismantling work mode When C is set on the first setting dial 33 (V mode), the dismantling work is performed. That is, at the time of dismantling work, the nuts tightened with a predetermined torque must be loosened and removed from the bolts and the like. When the nuts start to be loosened, the force acting on the hammer 4 and the anvil 2 is also large, and the nuts are loosened when the hammer 4 and the anvil 2 collide with each other. If the hammer 4 and the anvil 2 are sufficiently loosened, the collision between the hammer 4 and the anvil 2 will not be detected, the rotation of the spindle 8 will be continuously transmitted to the hammer 4 and the anvil 2, and the nuts will be continuously loosened. It will be in a state of being hammered. Therefore, if the timing to stop the motor 22 is delayed during such dismantling work, the nuts may be loosened too much and the nuts may be completely removed from the bolts or the like, and the nuts may fall and be lost. It was. Therefore, in the tightening tool of the present embodiment, the tightening tool is operated in the disassembly work mode by setting "C" to the first setting dial 33. That is, when the forward / reverse changeover switch 24 is set to the reverse position and the main switch 48 is turned on, the motor 22 rotates in the reverse direction, and the sound receiving unit 30 does not detect the collision between the hammer 4 and the anvil 2 before the predetermined value. The motor is programmed to stop after an hour. This predetermined time is determined by the number "n" of the second setting dial 35 ("n" x 0.1 seconds) as in the temporary tightening work mode described above.

[0022] Specifically, the microcomputer 38 first stores the time set by the number on the second setting dial 35 in the RAM 120. Then, the switching element 40 is turned on to rotate the motor 22, and the presence / absence of reception (presence / absence of collision) of the pulse wave output from the comparator 104 is monitored. The time from the reception of the first pulse wave to the reception of the next pulse wave is measured each time the pulse wave is received, and when this interval exceeds the preset time, the hammer 4 and anvil Judge that 2 is in a non-collision state. Then, when it is determined that the hammer 4 and the anvil 2 do not collide, the switching element 40 is continuously turned on so that the motor 22 rotates for the time stored in the RAM 120 from the time of the determination, and then the switching element 40 is turned on. Performs the process of turning off. In this way, according to the V mode, even if the operator keeps the main switch 48 on all the time, the motor 22 automatically stops a predetermined time after the collision between the hammer 4 and the anvil 2 is no longer detected. Therefore, the motor 22 automatically stops before the nuts are completely removed from the bolts and the like (in the state of being connected to the bolts). Therefore, it is possible to prevent the nuts and bolts from being lost due to the nuts being completely detached from the bolts and the like, and the dismantling work can be efficiently performed. When the forward / reverse changeover switch 24 is in the forward / reverse position, the motor 22 is started by turning on the main switch 48, and the motor 22 is continuously rotated until the main switch 48 is turned off (the striking count auto stop function is stopped).

(4) Tightening torque adjustment work mode When "D" is set on the first setting dial 33 (VI mode), the tightening torque adjustment work is performed. That is, with a tightening tool having a large maximum tightening torque, the tightening torque may not be adjusted by managing the number of collisions between the hammer 4 and the anvil 2. This is a case where the maximum tightening torque is too large and the tightening base material is destroyed by a single collision between the hammer 4 and the anvil 2. In such a case, it is conceivable to reduce the rotation speed of the motor 22 and adjust the tightening torque by adjusting the pulling allowance of the main switch 48, but when trying to adjust by the pulling allowance of the main switch 48, the operator It will be difficult to adjust the tightening torque properly because it depends on the experience and intuition of. Therefore, in the present embodiment, the tightening torque adjustment work is appropriately performed by setting "D" on the first setting dial 33. In this VI mode, the rotation speed of the motor 22 is adjusted to a preset predetermined rotation speed regardless of the position of the forward / reverse changeover switch 24 (either the forward / reverse changeover switch 24 may be in the forward / reverse position or the reverse position). To do.

[0024] In the case of the present embodiment, the rotation speed of the motor 22 when the main switch 48 is completely pulled out by the "n" set in the second setting dial 35 is set as a predetermined rotation speed. Specifically, when "n" is "0", it is the rotation speed of a normal motor. When "n" is "9", the rotation speed of the motor 22 is controlled to 90% of the rotation speed of the normal motor 22. When "n" is "8", the rotation speed of the motor 22 is controlled to 80% of the rotation speed of the normal motor 22. Similarly, when another number scale of the second setting dial 35 is selected, the rotation speed of the motor 22 is controlled to "n" x 10% by the number "n" set on the second setting dial 35. To do. In this VI mode, the hit count auto stop function is not so meaningful, so the hit count auto stop function is stopped.

(5) Repair work mode When "E" is set on the first setting dial 33 (VII mode), the repair work mode is set. That is, in this type of tightening tool, electrical components such as the dial setting unit 34 and the microprocessor 38 fail due to vibration caused by the collision between the hammer 4 and the anvil 2, and it becomes necessary to repair these components. In such a case, it is necessary to identify and replace the failed part, but it is difficult to identify the failed part, and it depends largely on the experience and intuition of the repairer. Therefore, in the present embodiment, by setting "E" on the first setting dial 33, the tightening tool is set to the repair work mode so that the faulty part can be easily identified.

That is, when the forward / reverse changeover switch 24 is set to the forward / reverse position in the VII mode, the motor 22 does not operate and maintains the stopped state even if the main switch 48 is turned on. Then, in the present embodiment, two seconds after the main switch 48 is turned on, a sound receiving unit that is shorter by the number of times of the value obtained by adding "1" to "n" set in the second setting dial 35 is received. It is programmed to generate from 30. For example, when "2" is set on the second setting dial 35, the sound is emitted only three times two seconds after the main switch 48 is turned on. That is, two seconds have passed since the microcomputer 38 detected that the main switch 48 was turned on, and then the sound receiving unit 30 outputs the sound by outputting the electric signal to the sound receiving unit 30 a predetermined number of times. Perform the processing to be performed. Thereby, for example, it can be determined whether or not the dial setting unit 34 is out of order based on the number of sounds generated from the sound receiving unit 30, and the timer operation of the microcomputer is normal at the timing when the sound is generated from the sound receiving unit 30. You can check whether or not it is. Therefore, the faulty part can be easily identified, and the repair work can be efficiently performed.

[0027] Further, when the forward / reverse changeover switch 24 is set to the reverse position in the VII mode, it is possible to check the detection (sound reception) operation of the sound receiving unit 30 and the stop operation of the motor 22 by the microcomputer 38. it can. That is, the motor 22 is started by turning on the main switch 48, and the housing 3 is tapped a predetermined number of times with a screwdriver or the like while maintaining the rotational operation of the motor 22. When it is determined that the sound receiving unit 30 has detected the sound generated when the housing 3 is hit a predetermined number of times, the microcomputer 38 is programmed to stop the motor 22. Here, the predetermined number of times to hit the housing 3 is set by the number of times of the value obtained by adding "1" to "n" set in the second setting dial 35. Thereby, for example, it is possible to determine the operation of the sound receiving unit 30 and whether or not the microprocessor 38 is functioning normally.

(6) Microcomputer check / battery check work mode When "F" is set on the first setting dial 33 (VIII mode), it is a mode for performing microcomputer check work and the like. That is, in the tightening tool of the present embodiment, the microcomputer 38 controls the operation of the motor 22 and the sound receiving unit 30 based on the control program stored in the ROM 118. Although the control program mounted on the microcomputer 38 is changed by version upgrade or the like, there is no change in appearance, so it is difficult to determine which version the microcomputer 38 is. Therefore, when it is necessary to replace the microcomputer 38 for repair or the like in the factory, it is not possible to easily determine which version of the microcomputer 38 should be replaced. Therefore, in the present embodiment, the version of the microprocessor 38 can be easily checked by setting "F" on the first setting dial 33.

That is, when the second setting dial 35 is set to "0" in the VIII mode, the version of the microprocessor 38 can be checked by turning on the main switch 48. Specifically, when the second setting dial 35 is set to "0", the forward / reverse changeover switch 24 is the version of the microcomputer 38 by turning on the main switch 48 in either the forward / reverse position or the reverse position. The sound indicating the chord is programmed to be generated from the sound receiving unit 30. For example, when the microcomputer 38 is version 2.1, the sound is emitted from the sound receiving unit 30 in a series of patterns of two long vowels and one short vowel at intervals of about one long vowel. At this time, the motor 22 does not operate and maintains the stopped state. As a result, the version of the installed microcomputer 38 can be easily checked, and the situation where the wrong version of the microcomputer 38 is installed can be prevented. Therefore, the replacement work of the microcomputer 38 can be efficiently performed.

[0030] Further, in the present embodiment, when "1" is set to the second setting dial 35 in this VIII mode, the battery voltage can be checked. That is, the forward / reverse changeover switch 24 is programmed so that a sound indicating the value of the battery voltage is generated from the sound receiving unit 30 by turning on the main switch 48 in either the forward / reverse position or the reverse position. .. Specifically, when the battery voltage is 23 volts, the sound is emitted from the sound receiving unit 30 in a series of two long vowels and an interval equivalent to about one long vowel, and then three short vowels. As a result, the battery voltage can be easily checked, and whether or not the battery needs to be replaced can be easily determined. Therefore, if such a battery check is performed before the start of the work, it is possible to prevent a situation in which the battery voltage drops and the tightening tool does not move during the work in the assembly factory or the like.

[0031] In the present embodiment, when "0" and "1" are set for the second setting dial 35 in this VIII mode, the above-mentioned microcomputer check function and battery check function are performed, and other numeric scales are performed. Did not have a function. However, it goes without saying that other functions may be realized by setting a function other than the above-mentioned function on the other digit scale of the second setting dial 35 and appropriately selecting the digit scale.

As described in detail above, in the tightening tool of the present embodiment, the motor 22 and the sound receiving unit 30 are controlled according to each work mode simply by setting the dial with the dial setting unit 34. It is programmed. Therefore, each work can be performed efficiently. Further, in the present embodiment, since the detection means (sound receiving unit 30) that converts the collision sound between the hammer 4 and the anvil 2 into an electric signal is used, conversely, an electric signal is input to the sound receiving unit 30. By doing so, it is possible to generate a sound and notify the operator of the version of the microcomputer 38 and the like. This eliminates the need to mount new parts on the conventional tightening tool.

[0033] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be implemented in each of the following embodiments. However, the embodiments shown below are merely examples, and the present invention should not be construed as being limited to the above-described embodiments or the following embodiments.

(1) In the above-described embodiment, as a means for detecting a collision between the hammer 4 and the anvil 2, a detection means for receiving a collision sound (such as a piezoelectric buzzer) is used, but a detection for detecting a collision is used. The means is not limited to the one that receives the collision sound. For example, means for detecting a collision by utilizing the retreat of the hammer in the axial direction (proximity switch, optical sensor, etc.), means for detecting when the current value of the motor changes (ammeter, etc.), rotation of the motor. Various means (frequency generator, etc.) for detecting by utilizing the change in angle can be used. When a collision is detected by a sound other than the collision sound, unlike the present embodiment, a notification means (light emitting diode or the like) other than the sound may be provided in order to realize the above-mentioned VII and VIII modes. good.

(2) In the above-described embodiment, all the settings are made by the dial setting unit 34, but the present invention is not limited to such a mode, and for example, a function that needs to be frequently switched and used (provisional). For tightening work and tightening work, etc.), switches that can be switched without removing the battery pack 122 may be separately provided in the housing.

(3) Although the tightening tool in which the hammer and the anvil collide with each other has been described in the above-described embodiment, the present invention is not limited to such a tightening tool, and other tools. It can also be applied to. For example, VI mode can be any tool that has a rotational drive source such as a motor and needs to adjust the motor speed, and VIII mode, for example, is equipped with a microcomputer or battery pack. It can be applied to any tool as long as it is.

Although some embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is implemented in various modifications and improvements based on the knowledge of those skilled in the art. be able to.

[Brief Description of Drawings] [Fig. 1] A partial cross-sectional side view of a tightening tool used in this embodiment.

FIG. 2 is a view seen from below (from direction II) with the battery pack of the tightening tool used in this embodiment removed.

FIG. 3 is an enlarged view of a setting dial.

FIG. 4 is a diagram showing a circuit configuration of a tightening tool used in this embodiment.

[Description of code] 2 Anvil 4 Hammer 24 Forward / reverse changeover switch 30 Sound receiving part 34 Setting dial 38 Microcomputer 48 Main switch