JP3918793B2 - Cordless fastening tool - Google Patents

Description

  The present invention relates to a cordless fastening tool such as a nut runner or a shear wrench used for fastening steel frames used in building construction, bridge construction, and the like.

Hereinafter, a shear wrench that shears the tip of the bolt with a constant shearing force and fastens the bolt with a constant torque will be described as a cordless fastening tool.

Utility Kaihei 6-53066 Utility Kaihei 6-11972 JP-A-4-217473 JP-A-1-210278 JP-A-6-31646

  FIG. 3 shows a shear bolt used for fastening a steel frame. At the tip of the bolts 41 of M16 to M24, a tip 42 to be gripped by the inner socket 16 at the time of tightening is provided, and a plurality of steel frames 44 are swallowed between the nut 43 and the head 40 of the bolt 41, as shown in FIG. The nut 43 is held by the outer socket 15 of the shear wrench shown, and the chip 42 is held by the inner socket 16, and tightened with a strong torque of 300 to 1000 Nm. The tip 42 has a constricted portion 45, and a constant tightening torque is obtained by utilizing the property that the constricted portion 45 can be threaded by a uniform shearing torque.

  Conventionally, the electric shear wrench used for this work has obtained power from a commercial AC power supply of 100 V to 200 V via a long cord 101 of 30 m to 60 m as shown in FIG. The rotation of the motor 102 is differentially reduced to about 1/1500 by the idle gear 3, the first gear 4, the small bevel gear 5, the large bevel gear 6, the three-stage planetary gear, etc., and between the inner socket 16 and the outer socket 15. In addition, a strong fastening torque of 300 to 1000 Nm was obtained. The handle 103 is attached so as to project rearwardly from the tail cover 106 at the rear end of the output unit so as to connect the output unit composed of the sockets 15 and 16, the planetary gears and the bevel gears 5 and 6 and the power unit such as the motor 102. It was. Inside the handle 103, the power switch 27 for opening and closing the connection between the motor 102 and the power source, and the rod 19 from the rear end of the small bevel gear 5 through the through hole in the gear using the suction force of the plunger 17 and the solenoid coil 18 are used. The sub-switch 28 for driving the solenoid-type chip discharge mechanism for pushing the chip 42 is housed.

The shear wrench has the following problems.
(1) This type of work is performed at high places such as buildings and bridges, with poor scaffolding and power supply conditions. However, in order to use a commercial power supply, it is necessary to route the cord 101 as long as 30 to 60 m, which is inefficient In addition, the motor 102 itself has a large input power of 1200 W or more in order to output a strong torque. For example, at 100 V, the current exceeds 13 A, and the voltage drop due to the resistance of the long cord 101 reaches 12 to 24 V. End up. For this reason, the fastening speed decreases due to the decrease in the motor rotation speed, the performance such as the discharge failure of the tip 42 due to the decrease in the suction force of the solenoid coil 18, and the code 101 becomes thick and heavy, resulting in poor operability.
(2) In order to solve these problems, a cordless fastening tool using a battery as a power source may be considered. However, the current technology requires a battery having a voltage of 24 V, a capacity of 2 Ah, and a mass of about 1.2 kg. However, because of the limit of the allowable current for motor burnout and switch contact welding, the current limit is about 30A at 24V, and the allowable input power of the motor obtained from this limit is about 24V x 30A = 720W. is there. In order to obtain the same torque with a motor that is 40% less powerful than AC100V, it is necessary to increase the reduction ratio from 1/1500 to 1/2400, which is 1.6 times that of the conventional motor. The spur gear such as the first gear 4 between 5 and 6 must be enlarged to increase the reduction ratio. Therefore, when the large bevel gear 6 is provided in front of the small bevel gear 5 as shown in FIG. 4, the overall length of the output portion (L dimension in FIG. 4) is increased due to the increase in the size of the first gear 4 engaged with the small bevel gear 5. Therefore, there is a possibility that the body does not enter the H-shaped steel for a long time in the tightening in the H-shaped steel having a dimensional limitation.
(3) When replacing the cassette type battery when the battery runs out during fastening, for example, at the corners of H-section steel, the upward direction of the main body and the longitudinal direction of the socket are close to the building. If the battery is inserted in the battery, the battery may not be removed.
(4) Since the size of the battery is a large size of 100 × 100 × 70 mm, the fitting of the nut 43 and the socket 15 may be hindered in a narrow space such as a corner portion of H-shaped steel.

(5) When the battery 31 is arranged below the handle 24c as in the conventional driver drill of FIG. 14, the output mechanism at the tip is heavy at about 2.5 kg in the case of a shear wrench, and tilts to the tip side. For this reason, if the main body cannot be stood and laid down, the main body will be raised when picking up the main body having a total weight of about 5 kg, and the operability is poor.
(6) In a high-output motor that is not available in a conventional cordless tool with an input power of about 720 W, the built-in magnet becomes stronger and larger than in the past, and the magnetic flux leaking outside the motor also increases. For this reason, when the main body is placed on a steel frame or a scaffolding plate as shown in FIG. 15, there is a high possibility that iron powder or iron chips on the steel frame or the scaffolding plate are attracted to the outer periphery of the motor housing. In order to withstand this large input power, the motor is equipped with a cooling fan, but the adsorbed iron powder and chips are attracted into the motor by the cooling fan and adhere between the rotor and magnet, resulting in mechanical loss. May increase.
(7) In addition to the weight of the main body being about 4 to 5 kg, the battery is added by 1.2 kg. Therefore, if the balance is not taken into consideration, it becomes heavy and inferior in operability.
(8) A heavy battery causes considerable damage to outer frame parts such as a housing when the main body is dropped, causing damage.
(9) In the structure in which the handle protrudes rearward with respect to the output part like the shear wrench in FIG. 4, the handle becomes obstructive in a narrow space such as in the H-shaped steel, or the work is called “Cachage” work. When tightening the bolts at the bottom of the foot (see FIG. 13), the handle is farther from the operator because the handle protrudes from the output portion, and the switch is difficult to operate.
(10) To improve the balance of the center of gravity, place the handle or motor close to the front socket, and if the position of the center of gravity and the grip of the handle are close, there will be no space for the hand around the socket, and the socket will become a nut. When inserting, it is difficult to hold with both hands (the handle with one hand and the socket with the other hand) and the operability is poor.
(11) Output mechanisms such as planetary gear trains, inner sockets, and outer sockets have a short life due to wear and galling, and need to be replaced periodically. However, since the output mechanism portion is directly fixed by the mounting bolts 107 hidden behind the bevel gear 6 in the inner cover 104 serving as a gear box, the output mechanism portion is separated by removing the mounting bolts during replacement repair. Requires removing the inner cover 104 from the housing 108, separating the gear cover 105 and the inner cover 104, separating the tail cover 106, and further removing the coil 18, the plunger 17, the large bevel gear 6, and the small bevel gear 5. , Repair is cumbersome and expensive.
(12) The chip discharge coil 18 operating at 100V, 60A must be driven with the power supply capacity of about 24V, 30A of the battery. However, because of the low voltage, the attractive force of the coil is insufficient, and the same chip discharge force cannot be obtained. In order to solve this, it is possible to cover the outer periphery of the coil with an iron plate to prevent leakage of magnetic flux, but this is not preferable because the space and the number of parts increase.
(13) If the battery runs out during fastening and the chip is not yet sheared, the residual torque due to torsional deformation of the members during this period remains in the shaft system from the motor pinion to the nut even when the power switch is turned off. Yes. Naturally, it rotates backwards to some extent, but it cannot be restored by the frictional resistance of the carbon brush of the motor, the mechanical loss of the gears in the middle, and the magnetic force of the magnet motor, and the remaining torsional torque causes the nut, outer socket, tip, and inner Friction resistance acts between the sockets, making it impossible to remove the body from the nut. In this case, the main body must be left on site until another fully charged battery is brought and replaced.

  An object of the present invention is to provide a compact cordless fastening tool that eliminates the drawbacks of the prior art described above, improves operability and reliability, and is easy to disassemble and repair.

  For convenience of the present invention, in the case of the fastening tool shown in FIG. 1, the upper side of the paper surface is referred to as the upper side of the tool, and the lower side of the paper surface is referred to as the lower side of the tool. Further, the left side of the paper surface is referred to as the front of the tool, and the right side of the paper surface is referred to as the rear of the tool.

The above-described object can be achieved by performing the following steps in the order described above.
(1) The power source is a detachable cassette type battery, or an adapter having a terminal part having substantially the same shape as the terminal part of the cassette type battery is provided, and the adapter is separated from the cassette type battery via a short cord. The external battery is used as a power source.
(2) A small bevel gear that engages with the first gear is provided in front of the large bevel gear.
(3) The direction in which the battery is attached and detached is perpendicular to the longitudinal direction of the socket and is the longitudinal direction of the handle.
(4) An output portion extending forward in a direction perpendicular to the longitudinal direction of the handle is disposed above the handle, and the battery is disposed below the handle that is in a position symmetrical to the output portion with respect to the handle.
(5) A battery is arranged below the handle and the motor that are symmetrical to the output part with respect to the handle and the motor, and the motor is located in a range where the longitudinal position of the center of gravity of the main body is within the bottom of the battery. To do.

(6) A battery is arranged below the handle and the motor so as to extend over them, and the width of the battery (B in FIG. 2) is made wider than the width of the motor housing (A in FIG. 2).
(7) An output unit is disposed above the handle and a motor unit is disposed in front of the handle, and a battery is disposed at a position straddling the handle and the motor at a position symmetrical to the output unit and below the handle and the motor.
(8) The motor housing, the battery insertion slot, the handle, and the outer frame of the output part are connected in a substantially rectangular shape.
(9) The handle and the battery are arranged at a position that is substantially the same as or slightly recessed from the rear end of the output unit located on the opposite side of the output unit from the outer socket.
(10) A space is formed between the outer socket and the motor housing.
(11) A plate-shaped inner cover that is separate from the gear box is provided at the output portion composed of a plurality of planetary gear trains and socket portions, and a gear cover that is an outer frame gear box that covers the bevel gear is attached to the gear cover from outside. Fix it.
(12) The first sun pinion serving as the shaft of the large bevel gear is made of a magnetic steel hollow structure, and a solenoid coil is disposed therein.
(13) An automatic return push button type switch that switches the rotation direction by switching the energization polarity of the motor is disposed between the motor and the battery. Alternatively, a portion where an auxiliary tool such as a spanner or a wrench can be attached is provided on any of the rotation shafts from the motor to the second ring gear, or the rotation shaft between the motor pinion and the second ring gear is rotated. Provide a clutch to disengage transmission.

The shear wrench configured as described above has the following operational effects.
(1) The battery does not have a long cord as long as several tens of meters as in the conventional AC100V product, and only a few tens of centimeters of lead wire inside the main unit or only a short cord from another battery. It is as small as 1/20, and is constant regardless of the length and thickness of the cord.
(2) By arranging the small bevel gear with which the first gear engages in front of the large bevel gear, the first gear whose outer diameter is about 1.6 times larger than the conventional one is not projected from the gear cover behind the output section. Can be placed.
(3) At work places where there are obstacles around the corner of the H-shaped steel, etc., the battery mounting / removal direction matches the longitudinal direction of the handle, which is the direction of the arm of the operator supporting the handle of the main body. The battery can be removed even if there are obstacles.
(4) Since the battery having a large shape is located farthest from the socket, the swing angle of the main body around the bolt can be increased as shown in FIG.
(5) Since the position of the center of gravity of the main body is in the bottom surface of the battery, even if the main body is placed with the battery facing down, it does not fall down. Therefore, it is not necessary to wake up the main body when placing or removing between work.

(6) Even if the main body is laid down on a steel frame or scaffolding plate with iron powder or swarf, the motor and motor housing will float several tens of millimeters without being in direct contact with the steel frame or scaffolding plate due to the wide battery. The magnetic force of the motor magnet does not reach the iron powder or swarf and does not attract or adhere to the motor or motor housing. Also, the suction force from the wind window of the cooling fan built in the motor does not reach.
(7) The weight of the battery is balanced with the weight of the output portion with respect to the handle, and the grip portion of the handle approaches the center of gravity of the main body, so that the balance is good.
(8) Since the outer frame is formed in a quadrangular shape by connecting the handle and the motor, the outer frame of the handle and the motor does not have a cantilever structure and is strong against dropping or hitting.
(9) Since the handle and the battery are not on a business trip than the output part with the longest length, the work in a narrow place is not disturbed.
(10) When holding the main body with one hand holding the outer socket, the hand enters the space provided between the outer socket and the motor housing, so hold the handle with the other hand and hold the main body with both hands. It can be held easily.
(11) The output part can be separated from the main body by simply removing the mounting bolts of the inner cover from the outside of the outer frame without disassembling other parts.
(12) Since the hollow first sun pinion prevents leakage of magnetic flux generated from the solenoid coil, the suction force can be increased without attaching a separate yoke.
(13) Even if the motor is stopped while the socket is stuck in a state where the battery is exhausted during fastening and the chip is not sheared, if the main switch is turned on while pressing the push button switch, a small amount of remaining battery is left. Since the motor can be rotated in reverse even with an amount of electricity, the residual torque in the main body is released by reverse rotation, the frictional resistance between the nut and the socket is eliminated, and the main body can be removed from the nut. Alternatively, the same effect can be obtained by reversing the motor rotation shaft with an auxiliary tool such as a spanner or a wrench. Alternatively, the same effect can be obtained by disengaging the clutch between the motor pinion and the second ring gear and releasing the residual torque.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

  FIG. 1 shows an embodiment in which the present invention is applied to a cordless shear wrench.

  A pinion 2 is press-fitted to the tip of the rotating shaft protruding above the motor 1, and the motor 1 is mounted in the motor housings 24a and 25a. Hereinafter, this part is referred to as a power unit 83. A power switch 27 that opens and closes between the motor 1 and the battery 31 is housed in handles 24c and 25c provided substantially parallel to the motor housings 24a and 25a. Hereinafter, this portion is referred to as a handle portion 82. A battery 31 is provided below the handles 24c, 25c and the motor housings 24a, 25a so as to straddle them. A terminal 30 that contacts the electrode 31a of the battery 31 is connected to the power switch 27. The battery 31 has a battery insertion portion 24d and 25d below the handles 24c and 25c which are symmetrical with respect to the handles 24c and 25c with respect to the handles 24c and 25c. The both ends of the handle 24c, 25c and the motor housing 24a, 25a are detachably held by a latch 32 and a latch 33. 2, when viewed from the side, the width B of the battery 31 is about 45 mm larger than the width A of the motor housings 24a and 25a, and the battery 31 having this width extends from the rear ends of the handles 24c and 25c to the motor housing 24a. , 25a extending to the position corresponding to the third position of the bottom. Hereinafter, this part is referred to as a power supply unit 84.

  In the motor housings 24a and 25a, an inlet side wind window 71 serving as a wind inlet of a cooling fan (not shown) built in the motor 1 is provided near the battery 31, and an outlet side wind window 72 serving as a wind outlet is provided near the pinion 2. ing. The battery 31 is attached and detached at right angles to the longitudinal direction of the socket and is the same as the longitudinal direction of the handles 24c and 25c. The weight of the output mechanism 50 is about 2.5 kg, and the weight of the battery 31 is about 1.2 kg. However, the position of the power switch 27 that is the grip portion of the handles 24c and 25c is above the handles 24c and 25c. 1/3 position, which is approximately equal to the height position of the center of gravity of the body.

  When the power switch 27 is turned on, the motor 1 and the pinion 2 are rotated and transmitted to the speed reduction mechanism 51. In the speed reduction mechanism 51, the gears 24b and 25b are decelerated by the idle gear 3 and the first gear 4, and further turned 90 degrees from the small bevel gear 5 press-fitted into the first gear 4, and provided at the right rear end in the figure. Is transmitted to the first bevel gear 6 and the first sun pinion 7 press-fitted thereto, and the rotation of the pinion 2 is decelerated to about 1/24. Hereinafter, this part is referred to as a speed reduction mechanism unit 51.

  The rotation of the first sun pinion 7 fixes the three-stage planetary gear train and the outer socket 15 for holding the nut, the inner socket 16 for holding the tip 42, and the sockets 15 and 16 to the gear covers 24b and 25b. Is transmitted to the output mechanism unit 50 including the inner cover 22 and the like.

  In the output mechanism 50, the rotation of the first sun pinion 7 is the second stage consisting of the first stage planetary gear train composed of the first idle gear 8 and the first ring gear 13, the second sun pinion 11, the second idle gear 9, and the first ring gear 13. The speed is reduced by a planetary gear train in the third stage including the planetary gear train, the third sun pinion 12, the third idle gear 10, and the second ring gear 14. Here, an outer socket 15 is connected to the second ring gear 14, and an inner socket 16 is connected to the first ring gear 13, and the rotational speed of the bevel gear 6 is reduced by the differential reduction of the first ring gear 13 and the second ring gear 14. Decelerated to 1/100. The reduction mechanism 51 and the output mechanism 50 are collectively referred to as an output unit 81, and the rotation of the motor 1 is reduced to about 1/2400 in the above transmission path, the torque increases to 500 Nm, and the nut 43 is tightened. The chip 42 is threaded by shearing, and as a result, the steel frame 44 is fastened with a torque of 500 Nm. The output mechanism 50 is fixed to the plate-like inner cover 22 with six machine screws 48, and the inner cover 22 has screw holes 49 provided on the outer periphery and screw holes 47 provided on the outer periphery of the gear covers 24b and 25b. Four mounting bolts 23 are fixed from the outside of the gear covers 24b and 25b.

  The threaded tip 42 is left in the inner socket 16 by turning on the sub-switch 28 in the handles 24c, 25c to hollow out the steel first sunpinion 7 and into it. A large current of 24 V and 30 A is supplied to the provided solenoid coil 18 from the control circuit 29 for several tens of milliseconds, and the plunger 17 in the coil 18 is attracted in the center direction of the coil 18, that is, in the left direction in FIG. 17, the hammer 20 is blown in the direction of the inner socket 16 on the left side of the figure through the rod 19 extending through the output mechanism section 50, and the chip 42 is ejected by colliding with the chip 42 remaining in the inner socket 16. .

  The outer frame parts of the present embodiment include a motor housing 24a, a handle 24c, a gear cover 24b, and an outer frame 24 formed of a resin molded product in which a battery insertion port 24d is integrally formed. Similarly, the motor housing 25a, the handle 25c, the gear cover 25b, The battery insertion opening 25d has a two-part structure of the outer frame 25 formed of an integral resin molded product. The handles 24c and 25c and the rear end surface of the battery 31 are arranged at a slightly recessed position with respect to the rear end surfaces of the gear covers 24b and 25b. In addition, it is preferable that the protrusion of the pinion 2 from the motor 1 is short in terms of strength. However, this is intentionally lengthened, and the motor housings 24a and 25a are recessed accordingly, and the space between the second ring gear 14 and the motor housings 24a and 25a. A space 74 into which the hand can enter is formed.

  As shown in FIG. 1, the positive and negative lead wires 35a and 35b from the battery 31 and the power switch 27 and the positive and negative lead wires 36a and 36b of the motor 1 are connected to the lower portion of the motor 1. A push button switch 34 having two circuits and three contacts for switching is provided. As shown in FIG. 12, when the push button switch 34 is released, the positive electrode of the battery 31 and the positive electrode of the motor 1 and the negative electrode of the battery 31 and the negative electrode of the motor 1 are directly connected. 12, the push button switch 34 is connected, and the positive electrode of the battery 31 and the negative electrode of the motor 1 and the negative electrode of the battery 31 and the positive electrode of the motor 1 are connected through a resistor 37 of several Ω. When the power switch 27 is pushed while pushing the push button switch 34, the voltage applied to the motor 1 drops by the resistor 37, and the motor 1 slowly reverses at a low speed. Normally, when the push button switch 34 is released, the push button switch 34 is automatically restored by the restoring force of the elastic member 39, and the push button switch 34 is connected as shown by the solid line in FIG. The motor 1 can be fastened and tightened.

  FIG. 5 is a view showing a fastening operation in the H-section steel 61 having dimensional limitations. Since the rear ends of the handles 24c and 25c and the battery 31 are not traveled from the rear ends of the gear covers 24b and 25b, and the small bevel gear 5 is provided forward even if the first gear 4 becomes larger, the gear cover is provided from the front end of the outer socket 15. 24b and the rear end of 25b become short and compact, and the fastening work in a narrow place like FIG. 5 is attained. Further, since the attaching / detaching direction of the battery 31 is the same as the longitudinal direction of the handles 24c and 25c and the direction of the operator's arm 62, the tool body is removed from the nut 43 even if the remaining battery 31 runs out during the fastening. Thus, the battery 31 can be attached and detached, and the work efficiency can be improved.

  FIG. 6 is a view before fastening, and the operator's hand can be put in the space 74 between the motor housings 24a, 25a and the outer socket 15 and the second gear ring 14, so that the outer socket 15 can be grasped sufficiently and the work can be performed. Efficiency can be improved and operator fatigue can be reduced.

  FIG. 7 is a diagram showing a disassembled state of the output mechanism unit 50. The output mechanism unit 50 can be removed simply by removing the four mounting bolts 23. The motor 1, the handles 24c and 25c, the spur gears 3 and 4, and the umbrella Since it is not necessary to remove the gears 5 and 6 and the coil 18 etc., disassembly and repair and assembly can be performed in a short time, which is economical.

  FIG. 8 is a diagram showing that the longitudinal center of gravity G of the tool body is above the handles 24c and 25c and within the range of the grip 73 near the power switch 27. FIG. That is, the output mechanism 50 having a weight of 2.5 kg and the battery 31 having a weight of 1.2 kg are attached to the top and bottom of the handles 24c and 25c, and the center of gravity G is positioned in the vicinity of the grip 73 as shown in the figure, so that the balance is good. Therefore, swinging is easy and the operator's fatigue can be reduced.

  FIG. 9 is a view showing a state in which the tool body is laid sideways on a steel frame 44 or the like. As described above, the width B of the battery 31 is made larger than the width A of the motor housings 24a and 25a. , 25a is not in direct contact with the steel frame 44 or the like, and floats about δ = 30 mm. For this reason, iron powder and chips 70 are not attracted by the permanent magnet in the motor 1 and are hardly attracted into the motor 1. As a result, the mechanical loss of the motor 1 is not increased and the reliability of the tool is increased.

  FIG. 10 is a view showing that the motor housings 24a and 25a, the gear covers 24b and 25b, and the handles 24c and 25c are formed by the integrated outer frames 24 and 25. FIG. The outer frames 24 and 25 are connected in the four directions of the output part 81, the handle part 82, the power part 83, and the power supply part 84, and are excellent in strength. The heavy battery 31 spans the motor housings 24a and 25a and the handles 24c and 25c. Therefore, the proof strength of the outer frames 24 and 25 becomes strong against the external force caused by the inertial force of the battery 31 due to dropping, collision, vibration, or the like. As a result, it becomes possible to form the outer frames 24 and 25 with a light and inexpensive synthetic resin, and to provide a cordless tool that is economical, lightweight, and has good operability.

  FIG. 11 is a diagram showing that the swing angle θ can be increased to about 170 degrees because the wide battery 31 is provided at the position farthest from the outer socket 15, and interferes with the obstacle 63 near the bolt 41 to be fastened. This eliminates the need to select a fastening location.

  FIG. 13 is a diagram showing a working situation in which the bolt is tightened from the bottom to the top. The work is performed while supporting the main body below the upper body of the operator, but the handles 24c and 25c are traveled from the gear covers 24b and 25b. Since the power switch 27 is approached as much as possible, the amount of arm extension is reduced, the operability is improved and the safety is increased.

  16 and 17 show another embodiment of the present invention. Instead of the cassette type battery 31, an adapter 55 is inserted into the battery insertion ports 24d and 25d, and the adapter 55 and the length of about 1.5 m are short. Electric power is supplied from an external battery 53 through a cord 54, and the tool body is lightened to improve operability. The external battery 53 is suspended from the operator's waist via a holding belt 56.

  FIG. 18 shows another embodiment below the motor 1, in which the rotating shaft of the motor 1 is protruded below the motor case, a minus groove 58 is provided at the tip, and the driver 57 is engaged with the minus groove 58. 1 can be manually rotated. Therefore, when the remaining amount of the battery 31 is reduced during the fastening and the outer socket 15 and the like cannot be removed from the nut 43, the motor 1 is reversed by the driver 57, and the outer socket 15 and the inner socket 16 are respectively connected to the nut 43. And it can remove from the chip | tip 42, and it will not leave a tool main body unattended. Although the rotating shaft of the motor 1 is projected downward, it may be projected upward and a minus groove is provided at the upper end of the rotating shaft and rotated by a driver or the like. Although the rotation shaft of the motor 1 is rotated, an arbitrary rotation shaft, for example, the shaft of the idle gear 3 may be rotated.

  FIG. 19 shows still another embodiment showing a recovery method in the case where the remaining amount of the battery 31 is reduced during the fastening and the outer socket 15 or the like cannot be removed from the nut 43. At the shaft portion of the small bevel gear 5, there is a clutch plate 69 that prevents rotation by the spline groove 76 and transmits the rotation, and is energized by a spring 68, so that the claw 65 of the clutch plate 69 meshes with the claw 64 of the first gear 4, The torsional torque transmitted from 16 is transmitted to the first gear 4 and brakes are applied by the resistance of the motor 1 to generate residual torque. Here, as shown in FIG. 20, when the lever knob 67a at one end of the lever 67 that is rotatable with the support shaft 75 as a fulcrum is lowered downward in the figure, the lever tip 67b rises and engages with the groove 69a of the clutch plate 69. The lever tip 67b pushes up the clutch plate 69 so that the claw 65 of the clutch plate 69 and the claw 64 of the first gear 4 are disengaged, and the small bevel gear 5 and the clutch plate 69 are idled and the motor 1 brakes. The first gear 4 is released. Therefore, the outer socket 15 and the inner socket 16 can be detached from the nut 43 and the chip 42 by reversing the outer socket 15, respectively.

According to the above-described embodiment, the following effects can be obtained in the order of the problems.
(1) Since it is battery-driven cordless, there is no need to route a long cord and it is efficient and there is no fear that the cord will be caught on the steel frame. In addition, since there is no voltage drop due to a long cord, there is no reduction in fastening speed, which is efficient. Furthermore, since there is no weight to route the cord, operator fatigue is reduced. The cordless shear wrench of this configuration can be attached with the external battery 53 and the adapter 55 shown in FIGS. 16 and 17, and if this is used, only a short cord comes out from the lower part of the handle. It can be used in the same manner as a corded shear wrench, and a heavy battery can be suspended by a holding belt, so that operability is further improved and has the advantages of the cordless shear wrench described above.
(2) Even if the first gear 4 becomes larger, the small bevel gear 5 is moved forward by that amount, so the length from the outer socket 15 to the rear ends 38 of the gear covers 24b and 25b is short and compact. For this reason, it is advantageous in the tightening operation in the H-section steel 61 having a dimension limitation as shown in FIG.
(3) Even if there is an obstacle around the corner portion of the H-shaped steel 61 and the remaining amount of the battery 31 runs out during fastening, the operator's arm that supports the tool body when the battery 31 is attached or detached Since the direction is the same as the direction 62, the battery 31 can be conveniently attached and detached without moving the tool body from the bolt 40 as shown in FIG.
(4) Since the battery 31 is below the handles 24c and 25c farthest from the outer socket 15, the angle θ that swings with respect to the bolt 41 is as large as 170 degrees as shown in FIG. For this reason, the battery 31 rarely interferes with the obstacle 63 in the vicinity of the bolt 41 to be tightened.
(5) Since the center of gravity G in the longitudinal direction of the tool body is within the length C of the bottom surface of the battery 31 as shown in FIG. Therefore, there is no need to raise a heavy tool body when placing or removing the tool body between operations, and operability is good.

(6) Even if the tool body is placed on a steel frame 44 or a scaffold plate with iron powder or swarf 70 as shown in FIG. 9, the motor 1 and the motor housings 24a and 25a can be Δ = 30 mm without being in direct contact with the motor 1, so that iron powder and chips 70 are adsorbed by the magnetic force of the permanent magnet of the motor 1, and the cooling fan of the motor 1 is sucked into the motor 1 from the inlet-side wind window 71 and becomes permanent. There is no fear of increased mechanical loss between the magnet and the core, increasing reliability.
(7) As shown in FIG. 8, since there are the output mechanism section 50 weighing 2.5 kg and the battery 31 weighing 1.2 kg above and below the handles 24 c and 25 c, the grip 73 near the main switch 27 above the handle There is a longitudinal center of gravity G of the tool body within the range, and the balance is good and swinging is easy and not tired.
(8) As shown in FIG. 10, the outer frames 24 and 25 are connected in the four directions of the output portion 81, the handle portion 82, the power portion 83, and the power source portion 84, and are excellent in strength and have a heavy battery 31 in the motor housing 24a. , 25a and the handles 24c, 25c, the outer frames 24, 25 are more resistant to the external force caused by the inertial force of the battery 31 due to dropping, collision, vibration, or the like. As a result, the outer frames 24 and 25 can be made of a light and inexpensive synthetic resin molded product, which is economical, lightweight and easy to operate.
(9) Since the handles 24c and 25c and the battery 31 are not on a business trip from the rear ends 38 of the gear covers 24b and 25b of the tool body as shown in FIG. 5, the handles 24c and 25c and the battery 31 are obstructive when working in a narrow place. Rather, it is possible to work in a deep and narrow place that has never been possible before. Further, in the case where the bolt as shown in FIG. 13 is tightened from the bottom to the top, the work is performed while supporting the tool body below the upper body of the operator, but the power switch is not used because the handles 24c and 25c are not on a business trip. Since 27 approaches, the amount of arm extension is reduced, operability is improved and safety is increased.
(10) When the outer socket 15 is inserted into the nut 43 while holding the main body with both hands as shown in FIG. 6, the hand enters the space 74 between the motor housings 24 a, 25 a and the outer socket 15 and the second ring gear 14. It is easy to hold the outer socket 15 and does not get tired.
(11) As shown in FIG. 7, four mounting bolts 23 are provided from the outside without disassembling the built-in components such as the motor 1, the handles 24c and 25c, the spur gears 3 and 4, the bevel gears 5 and 6, and the solenoid coil 18. Since the output mechanism 50 can be removed simply by removing it, the repair time is short and economical.
(12) Covering the outer side of the coil 18 with the steel first sun pinion 7 as shown in FIG. 1 reduces the leakage of magnetic flux and improves the discharge power of the chip 42 five times before covering, and the 24V battery 31 However, it can be discharged as much as conventional AC100V products. Moreover, since the yoke is also used as the shaft portion of the first sun pinion 7, it is economical without adding new parts.
(13) Even if the remaining amount of the battery 31 runs out during the fastening, the residual torque due to the torsional deformation of the member accumulated in the shaft system from the pinion 2 to the nut 43 can be released by reversing the motor 1, so that the outer socket 15 Since there is no frictional resistance between the nut and the nut 43 and the tool body can be removed without resistance from the nut 41, the tool body is not left in the suspended state while being bitten on the nut 43 when the battery 31 is replaced. Safe without fear. The above effect is the same even without the resistor 37, but when a current flows to the motor 1 through the resistor 37 in FIG. 12 during reverse rotation, the voltage applied to the motor 1 drops and the rotation speed and torque are low slowly. It is safe because it rotates. 18, the motor 1 and the sockets 15 and 16 can be rotated by the clutch plate 69 provided in the rotation shaft as shown in FIGS. The same effect can be obtained by disconnecting the transmission. The clutch plate 69 may be of any type as long as it can fully transmit, such as a friction plate type or a spring clutch type, in addition to the claw type.

  Although the above embodiment has been described by taking a shear wrench as an example, the present invention can be applied to a cordless fastening tool in general.

Sectional drawing of the cordless shear wrench which shows one Example of this invention. The right view of FIG. Sectional drawing which shows the attachment state of a shear bolt. Sectional drawing which shows the conventional shear wrench with a cord. The perspective view which shows the working state in the H-section steel corner part by this invention shear wrench. The front view which shows the state before work of this invention shear wrench. The front view which shows the decomposition | disassembly state of the output mechanism part of this invention shear wrench. The right view which shows the gravity center balance of the shear wrench shown in FIG. The right view which shows the state which left this invention shear wrench on the steel frame. The front view which shows the gravity center balance of this invention shear wrench. The right view which shows the swing angle of this invention shear wrench. The circuit diagram which shows the electrical wiring of this invention shear wrench. The front view which shows the state which is carrying out the cathage work with this invention shear wrench. The front view which shows the gravity center arrangement | positioning at the time of battery arrangement | positioning similar to the conventional cordless drill etc. The side view at the time of leaving on the steel frame at the time of battery arrangement | positioning similar to the conventional cordless drill etc. Front sectional drawing which shows the other Example of this invention cordless shear wrench. The side view of FIG. Sectional drawing of the motor downward direction which shows the other Example of this invention. The principal part sectional drawing which shows the further another Example of this invention. The principal part expanded sectional view of FIG.

Explanation of symbols

In the figure, 1 is a motor, 2 is a pinion, 3 is an idle gear, 4 is a first gear, 5 is a small bevel gear, 6 is a large bevel gear, 7 is a first sun pinion, 15 is an outer socket, 16 is an inner socket, 18 Is a solenoid coil, 19 is a rod, 20 is a hammer, 21 is a hammer spring, 22 is an inner cover, 23 is a mounting bolt, 24 and 25 are outer frames, 24a and 25a are motor housings, 24b and 25b are gear covers, 24c and 25c. Is a handle, 27 is a power switch, 28 is a sub-switch, 29 is a control circuit, 31 is a battery, 31a is a battery electrode, 35a and 35b are power leads, 36a and 36b are motor leads, 37 is a resistor, 38 is Rear end face of gear cover, 41 is a bolt, 42 is a chip, 43 is a nut, 44 is a steel frame, 50 is an output mechanism, 51 is a deceleration構部, 52 scaffolding plate 70 is iron powder or chips, 71 the inlet side air windows, 72 an outlet side air windows, 81 output unit, 82 handle, 83 a power unit, 84 is a power supply unit.

Claims (5)

A power unit having a motor and a motor housing that houses the motor; a power switch; a handle unit that extends along a direction parallel to the rotation axis of the motor; and a longitudinal direction of the power unit and the handle unit. A spur gear provided on one end side for reducing the rotation of the rotation shaft of the motor, a small bevel gear and a large bevel gear for reducing the rotation direction of the spur gear, and the spur gear and the small bevel A speed reduction mechanism having a gear cover for housing the gear and the bevel gear, and a bolt or nut that is provided to extend in a direction perpendicular to the rotation shaft of the motor and is fastened by a driving force that is reduced by the speed reduction mechanism. A cordless fastening tool comprising an output mechanism portion having a tip member for rotating a shaft, having a gear made of a magnetic body connected to the large bevel gear, and discharging a broken bolt member Mounted for sliding fit of the rod to the output mechanism, a solenoid coil means for driving the rod is provided on the inside of the gear made of the magnetic body, a longitudinal direction of the power unit and the handle portion A power supply unit for storing the battery is detachably provided on the other end side opposite to the one end, and the power supply unit is in a direction across the power unit and the handle unit and has the rotating shaft. Is arranged at a position such that a line extending the center of gravity of the entire tool in parallel with the rotation axis of the motor intersects the power supply unit having the length C. And the mounting direction of the power supply unit is a direction parallel to the rotation axis of the motor, and the power supply unit in a direction perpendicular to the direction having the length C and perpendicular to the rotation axis of the motor. The width B is Cordless fastening tool, characterized in that larger than the width and the width of the power unit of the dollar portion.   2. The fastening tool according to claim 1, wherein an air window for cooling the motor is provided in the motor housing.   The rotation of the rotating shaft of the motor is decelerated by a plurality of spur gears, and the rotation of the final stage spur gear is decelerated by changing the rotation direction via a small bevel gear and a large bevel gear meshing with the small bevel gear, and The large bevel gear is disposed in the gear cover so as to be positioned between the end portion of the speed reduction mechanism portion opposite to the output mechanism portion and the small bevel gear. The cordless fastening tool according to 1.   2. The end face of the handle portion extending in a predetermined direction parallel to the rotation axis of the motor and perpendicular to the length C direction of the power source portion is flush with the end surface of the gear cover extending in the predetermined direction. Or a cordless fastening tool configured to extend along a plane closer to the rotating shaft.   The front end portion of the output mechanism portion is composed of an outer socket that fits into the nut and rotates the nut, and an inner socket that fits into the bolt and rotates the bolt to break the constricted portion of the bolt. The cordless fastening tool according to claim 1, wherein the cordless fastening tool is a wrench.

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