JP5928803B2 - Blind rivet fastening device - Google Patents

Description

  The present invention relates to an electric blind rivet fastening device that uses an electric motor, and in particular, a blind rivet fastening device that does not require a passage for collecting a mandrel that is broken after the blind rivet is fastened to the shaft center of the electric motor. About.

  The blind rivet includes a mandrel and a rivet body, and the rivet body includes a hollow cylindrical sleeve and a large-diameter flange formed on one of the cylindrical sleeves. The mandrel includes a shaft portion having a portion that penetrates the rivet body and extends long from the flange and is gripped by the blind rivet fastening device, and a cylindrical sleeve that is disposed so as to protrude adjacent to the other end side of the cylindrical sleeve. It consists of a mandrel head with a diameter larger than the inner diameter. The blind rivet is held by the blind rivet fastening device in a state where the grip portion of the mandrel shaft portion is inserted into the nose of the blind rivet fastening device and the rivet body and the mandrel head come out of the nose. In the blind rivet held by the blind rivet fastening device, the sleeve of the rivet body is inserted into the mounting hole of the fastened member, and the flange comes into contact with the fastened member.

  Next, the mandrel shaft portion is strongly pulled out by the operation of the pulling head of the blind rivet fastening device, the mandrel head expands and deforms a part of the sleeve, and the fastened member between the expanded and deformed sleeve portion and the flange Is strongly clamped and broken by a breakable portion having a small diameter formed in the mandrel shaft, whereby the rivet body is fastened to the fastened member. When the fastened member is a vehicle body panel and a component attached to the vehicle body panel, the blind rivet is fastened to both members in a state where the mounting portion of the component is overlapped on the vehicle body panel, so that the component is fixed to the vehicle body panel. Is done. The blind rivet has an advantage that a fastening operation can be performed from one side even if the panel is a panel having a large area such as a vehicle body panel as a member to be fastened. In general, the blind rivet is made of a metal material such as steel or aluminum. After fastening, the shaft portion of the mandrel where the blind rivet is broken needs to be recovered from the blind rivet fastening device.

  Patent Document 1 discloses an electric blind rivet fastening device using an electric motor driven by a battery as one of blind rivet fastening devices. The electric motor held by the handle drives the blind rivet fastening mechanism, the mandrel head part expands and deforms the grip part of the mandrel shaft part of the blind rivet held by the nose, and the mandrel shaft part Is pulled out so as to be broken at the breakable portion having a small diameter, and the blind rivet is fastened to the fastened member. Unlike a pneumatically operated blind rivet fastening device or a hydraulically operated blind rivet fastening device, an electric blind rivet fastening device driven by a battery is connected between a supply source of pressure fluid such as pneumatic or hydraulic pressure and a handle. This eliminates the need for the pressurized fluid supply tube, reduces the burden on the operator having the handle, and facilitates the fastening operation.

  In the electric blind rivet fastening device described in Patent Literature 1, a collection container for collecting the broken mandrel shaft portion is disposed behind the blind rivet fastening mechanism. In this electric blind rivet fastening device, a large electric motor is arranged at the upper part of the handle, the shape of the fastening device is large at the upper part of the handle, and the electric motor at the upper part of the handle and the nose part at the front of the fastening device are heavy. Therefore, the weight balance of the fastening device is not good. For this reason, it is difficult for the worker to hold the handle, and the worker cannot work comfortably.

  Patent Document 2 discloses an electric blind rivet fastening device using an electric motor. In this apparatus, a blind rivet fastening mechanism, a collecting container of a broken mandrel shaft portion, and an electric motor between the fastening mechanism and the collecting container are arranged coaxially in a substantially cylindrical housing. In this electric blind rivet fastening device, since the electric motor is arranged behind the upper portion of the handle, the overall weight of the device is better compared to the fastening device described in Patent Document 1, and the operator can easily hold the handle. The worker can work comfortably.

  In the electric blind rivet fastening device of Patent Document 2, since a motor is provided between the blind rivet fastening mechanism and the collection container of the broken mandrel shaft portion, a passage for collecting the broken mandrel shaft portion serves as a shaft of the motor. A hollow is formed in the shaft center of the motor, and the electric motor to be used must be formed in a special structure. It is desirable that a general-purpose electric motor that does not require a recovery passage for the broken mandrel shaft at the shaft center can be used for the electric blind rivet fastening device.

  Patent Document 3 discloses a hydraulically driven blind rivet fastening device controlled by an air pressure control mechanism. This blind rivet fastening device includes a blind rivet fastening mechanism housed in a cylindrical housing and a handle extending so as to be substantially orthogonal to the housing of the cylindrical fastening mechanism. A recovery container for a broken mandrel shaft is provided at the rear end of the fastening mechanism housing. When a trigger lever provided on the handle is operated, an air pressure control mechanism provided in the handle is operated to operate a hydraulic control mechanism of the blind rivet fastening mechanism. A strong pulling force acts on the mandrel shaft part of the blind rivet held by the nose, and the mandrel head part is expanded and deformed while the mandrel head part is expanded and deformed. Fastened to the fastened member and the broken mandrel shaft is collected in the collection container.

  The blind rivet fastening device of Patent Document 3 requires that a pressurized air supply tube extending from a pressurized air source be connected to the handle, and this supply tube places a burden on the operator's work. It is not possible to desire an easy operation that does not require a fluid supply tube, such as the two battery-driven electric blind rivet fastening devices, and it is not possible to release the troublesome operation associated with the routing of the supply tube.

Patent Document 4 discloses an electric blind rivet fastening device using an electric motor. The device of Patent Document 4 is provided with a recovery container that accommodates the shaft portion of the mandrel in the axially forward portion of the handle at the upper portion of the handle, and the electric motor is disposed axially rearward of the recovery container. A power transmission means is further provided for bypassing the collection container and transmitting the rotation of the electric motor to the pulling head. In this apparatus, since the recovery container for the broken mandrel is provided at a position in front of the electric motor, there is no need to provide a passage for collecting the broken mandrel in the shaft center of the motor.
The device of Patent Document 4 is provided with power transmission means bypassing the recovery container, and detects the rotation of the drive shaft passing under the recovery container using a mechanical switch to determine the position of the pulling head. The mechanical switch occupies the volume under the collection container, so that the volume in which the collection container can be installed is small.

Therefore, there has been a demand for a small-sized blind rivet fastening device that does not require a passage for collecting the broken mandrel and that can be driven by a battery.
There has also been a demand for a blind rivet fastening device that can increase the volume of a recovery container for recovering a broken mandrel.

Japanese Patent Laid-Open No. 5-200476 JP 2003-266143 A JP 2008-168324 A JP 2011-218381 A

An object of the present invention is to provide a small-sized blind rivet fastening device that can be driven by a battery and does not require a passage for collecting a broken mandrel in the shaft center of the motor.
Another object of the present invention is to provide a blind rivet fastening device capable of increasing the volume of a recovery container for recovering a broken mandrel.
Another object of the present invention is to provide a blind rivet fastening device capable of avoiding an abnormal torque applied to the device.

  In the present invention, the collection container of the mandrel is disposed in front of the brushless motor, and the rotation of the electric motor is transmitted to the pulling head by bypassing the collection container by the second shaft provided below the collection container. The position of the pulling head is obtained from the rotation of the brushless motor. Therefore, no mechanical switch is required, the volume of the collection container can be increased, and durability is improved. In addition, a clutch is provided to position the home position of the pulling head to avoid applying an abnormal torque.

According to one aspect of the present invention, the sleeve portion of the rivet body is deformed so as to expand the diameter by pulling the mandrel of the blind rivet including the mandrel and the rivet body in the axial direction, and the expanded sleeve portion and the rivet body A blind rivet fastening device that fastens the rivet body to a member to be attached by the flange of the rivet, and breaks the mandrel,
An electric motor disposed at one end;
Power transmission means for transmitting rotation of the electric motor;
A spindle that is arranged in front of the electric motor and that is rotated by being transmitted power by the power transmission means;
A ball screw nut adjacent to the spindle and connected to the spindle for rotation;
A ball screw shaft provided at a central portion in the axial direction of the ball screw nut and moving in the axial direction by rotation of the ball screw nut;
A pull-in means connected to the ball screw shaft and gripping and pulling the shaft portion of the mandrel;
A rotational speed detection element for detecting the rotational speed of the electric motor;
A trigger provided on the handle,
Control means for controlling forward rotation, reverse rotation, and stop of the electric motor according to the pulling operation of the trigger and the rotation speed of the electric motor;
A blind rivet fastening device comprising:

The battery-driven electric blind rivet fastening device according to the present invention can determine the position of the pulling head by detecting the rotation of the electric motor. Therefore, a mechanical switch for determining the position of the pulling head is unnecessary, and durability can be improved.
In the electric blind rivet fastening device, since the recovery container for the broken mandrel is provided at a position in front of the electric motor of the tool housing, there is no need to provide a passage for recovering the broken mandrel in the shaft center of the motor. A recovery container for the rupture mandrel is disposed between the electric motor and the spindle, can transmit power by bypassing the recovery container, and the position of the pulling head can be obtained by detecting the rotation of the electric motor. Therefore, a mechanical switch for determining the position of the pulling head is unnecessary, and the volume of the collection container can be increased.

In the blind rivet fastening device, the pull-in means is
A pulling head that moves in the axial direction by the axial movement of the ball screw shaft;
A jaw case that is disposed integrally with the pulling head adjacent to the pulling head and has an inner peripheral surface with a smaller inner diameter toward the front end;
A jaw that is disposed within the jaw case and has an outer peripheral surface that abuts against an inner peripheral surface of the jaw case;
A nosepiece disposed adjacent to the jaws and having an opening through which the mandrel shaft is passed.
As a result, the shaft portion of the mandrel can be securely gripped and pulled in, and the blind rivet can be fastened.

In the blind rivet fastening device, the power transmission means is
A motor gear coupled to the electric motor; a rear gear provided below the motor gear and engaged with the motor gear; a spindle gear engaged with the spindle; and a spindle gear provided below the spindle gear and engaged with the spindle gear. And a second shaft that is provided below the collection container and integrally couples the rear gear and the front gear.
Accordingly, power can be transmitted by bypassing the collection container from the electric motor to the spindle by the second shaft parallel to the shaft of the electric motor.

In the blind rivet fastening device, the electric motor may be a brushless motor.
With a brushless motor, the number of rotations of the motor can be accurately controlled.
In the blind rivet fastening device, the rotation speed detecting element may be a Hall element.
The rotation of the electric motor can be easily detected by the Hall element included in the brushless motor.

In the blind rivet fastening device, a spindle clutch having a cylindrical portion and a fan-shaped portion, movable in the axial direction with respect to the spindle, and rotating integrally with the spindle;
A first clutch that includes a fan-shaped portion that engages with the fan-shaped portion of the spindle clutch and includes a nut clutch integrally coupled to the ball screw nut;
The first clutch can release the engagement between the spindle clutch and the nut clutch, and can prevent the rotation of the spindle from being transmitted to the ball screw nut.
Thereby, it is possible to prevent the pulling head from being pulled too much.

  When the ball screw shaft reaches the rear end portion in the axial direction, the tail convex portion of the cylindrical tail integrally joined to the rear end portion of the ball screw shaft pushes the inner end face of the spindle clutch rearward in the axial direction. The engagement between the fan-shaped portion of the spindle clutch and the fan-shaped portion of the nut clutch may be released.

In the blind rivet fastening device, the rear clutch is cylindrical, has a sawtooth at the front end, is axially movable around the pulling head, and is non-rotatably disposed.
It is cylindrical and has a saw blade that engages with the saw blade of the rear clutch at a rear end portion, is disposed in front of the rear clutch, is disposed around the pulling head, and is integrally coupled with the pulling head. A second clutch including a front clutch can be provided.
As a result, the pulling head can be prevented from moving forward from the home position.

The saw blade of the rear clutch has one surface parallel to the axial direction of the rear clutch and the other surface inclined with respect to the axial direction.
The saw blade of the front clutch may have a shape that engages with the saw blade of the rear clutch.

  When the ball screw shaft reaches the front end, the ball screw shaft does not move in the axial direction, rotates with the ball screw nut, the front clutch rotates, and the rear clutch moves backward in the axial direction, The front clutch may rotate.

ADVANTAGE OF THE INVENTION According to this invention, the small blind rivet fastening device which can be driven with a battery which does not need to provide the channel | path for collection | recovery of a breakable mandrel in the shaft center of a motor can be provided.
In addition, according to the present invention, it is possible to provide a blind rivet fastening device that can increase the volume of a recovery container for recovering a broken mandrel and has improved durability.
Further, according to the present invention, it is possible to provide a blind rivet fastening device that can avoid applying an abnormal torque to the device.

1 is a front view of an electric blind rivet fastening device according to an embodiment of the present invention. It is a fragmentary perspective view which fractures | ruptures and shows the rear part of the fastening mechanism of the electric blind rivet fastening apparatus of FIG. It is a longitudinal cross-sectional view of the front part of the fastening mechanism of the electric blind rivet fastening device of FIG. 1, and shows a state in which the blind rivet is attached to the nose. FIG. 4 is a longitudinal sectional view of a nose portion at the tip of the fastening mechanism of FIG. 3, showing a state where a broken mandrel shaft portion of a blind rivet remains in the nose portion. It is the perspective view which removed a part of nose part of the electric blind rivet fastening device of FIG. It is the perspective view which removed a part of part of the 1st clutch. It is the perspective view which removed a part of part of the 2nd clutch. It is the perspective view which removed a part of part of the 2nd clutch. It is the perspective view which removed a part of part of the 2nd clutch. It is a block diagram of the power transmission and control part of the electric blind rivet fastening device of FIG.

  Hereinafter, one embodiment of an electric blind rivet fastening device according to the present invention will be described with reference to the drawings. FIG. 1 is a front view of an electric blind rivet fastening device according to an embodiment of the present invention. The electric blind rivet fastening device 1 includes a blind rivet fastening mechanism 2 housed in a substantially cylindrical housing, and a handle 3 extending so as to hang substantially perpendicularly from an intermediate position of the fastening mechanism 2. A battery is detachably attached to the battery holding portion 5 at the lower portion of the handle 3. A trigger 6 is provided at a position adjacent to the fastening mechanism 2 of the handle 3. When the operator pulls the trigger 6, the fastening mechanism 2 is operated to perform the fastening operation of the blind rivet, and the fastening mechanism 2 is returned to the home position HP (front end position) by releasing the pulling operation of the trigger 6. Release (or stop) the operation.

  The blind rivet fastening mechanism 2 includes a front (right side in FIG. 1) nose 7, a rear (left side in FIG. 1) motor unit 9, and a central power transmission / control unit 11. The nose 7 is provided with a pulling head 30 (FIG. 3 and the like) for pulling out the mandrel shaft portion of the blind rivet strongly rearward (left side in FIG. 1), and the motor portion 9 accommodates an electric motor 13 composed of a brushless motor. Is done.

(Brushless motor)
FIG. 2 shows the structure of the motor unit 9 and the power transmission / control unit 11 of the electric blind rivet fastening device 1 according to the present invention. First, the motor unit 9 will be described. In the present invention, the electric motor 13 is a brushless motor. In the brushless motor, the rotor is a magnet and the winding circuit is on the stator side. The rotation angle of the rotor is detected by a hall element (magnetic sensor) 13A incorporated in the electric motor 13. The electronic circuit 13B for the brushless motor performs switching at a timing according to the magnetic poles of the rotor. The brushless motor can determine the position of the pulling head by detecting the rotation of the rotor. A known element other than the Hall element can be used for detecting the rotation of the rotor. Brushless motors are well known and will not be described in further detail.

(Recovery container)
Between the nose 7 and the motor unit 9, a broken mandrel shaft collection container 10 is provided on the top of the handle 3. The collection container 10 is formed in a semicircular cylindrical shape and is surrounded by a transparent or translucent cover 10A. Through the cover 10A, the accommodated broken mandrel shaft can be seen from the outside. The cover 10A is formed to be openable and closable so that the broken mandrel shaft portion can be discarded.

  From the position where the collection container 10 is located, the handle 3 extends obliquely downward so that the operator can easily grasp the blind rivet fastening device 1. Since the collection container 10 is disposed at an intermediate position of the tool housing 27, there is no need to install a mandrel collector at the rear end of the tool housing as in Patent Document 2, and work by the weight of the electric motor as in Patent Document 1 The instability in the case of hand-held to the person can be eliminated.

(Power transmission mechanism)
A power transmission / control unit 11 is provided between the motor unit 9 and the nose 7 in a lower part of the collection container 10. The power transmission / control unit 11 rotates the electric motor 13 by a power transmission mechanism that transmits the rotational force (torque) of the electric motor 13 of the motor unit 9 to the spindle 14 in the nose 7 and a trigger pulling operation and a releasing operation thereof. And a control mechanism for controlling the forward and backward movements of the pulling head of the nose 7 through the rotation of the spindle 14. The electric blind rivet fastening device 1 performs blind rivet fastening with an electric motor 13 that uses a battery as a power source, and thus does not require a fluid supply tube such as pressurized air, and is free from troublesome work associated with the routing of the fluid supply tube. Is done.

  The power transmission / control unit 11 has a mechanism for transmitting the rotational force from the electric motor 13, which is a brushless motor of the motor unit 9, to the spindle 14 of the nose 7, bypassing the space occupied by the collection container 10. A motor gear 15 connected to the motor shaft of the electric motor 13 is disposed on the rear side of the collection container 10, and connected to a spindle 14 having an axis coaxial with the axis of the motor shaft on the front side of the collection container 10. A spindle gear 17 is arranged.

  A second shaft 18 is provided between the motor gear 15 and the spindle gear 17 in the space below the collection container 10. The second shaft 18 is supported so as to be rotatable about the axis in the front-rear direction (that is, the axial direction) of the blind rivet fastening mechanism 2 and in a direction parallel to the axis of the motor shaft of the electric motor 13 and the spindle 14. Yes. A rear gear 19 that engages with the motor gear 15 is attached to the rear end of the second shaft 18, and a front gear 21 that engages with the spindle gear 17 is attached to the front end of the second shaft 18. The second shaft 18 is a single shaft, and couples the rear gear 19 and the front gear 21.

  Since the rear gear 19 is engaged with the motor gear 15, the second shaft 18 rotates reversely when the electric motor 13 rotates forward. Since the front gear 21 is engaged with the spindle gear 17, when the second shaft 18 rotates in the reverse direction, the spindle gear 17 rotates in the normal direction and the spindle 14 rotates in the normal direction. As a result, the spindle 14 rotates in the same direction as the electric motor 13. The gear ratio between the motor gear 15 and the rear gear 19 and between the front gear 21 and the spindle gear 17 is arbitrarily determined depending on the balance between the output of the electric motor 13 and the fastening force of the blind rivet.

The power transmission / control unit 11 further includes a control mechanism for controlling the electric motor 13 to rotate forward, stop, and reversely rotate by pulling the trigger 6 and releasing it. As described above, the rotation of the electric motor 13 is transmitted to the spindle 14 via the second shaft 18. The control mechanism controls the electric motor 13 in response to the pulling operation of the trigger 6 and the releasing operation thereof, thereby causing the pulling head 30 of the nose 7 to break the mandrel shaft portion of the blind rivet from the home position HP. The vehicle is moved back to the position RP, stopped at the rear end position RP, and released from the rear end position RP by releasing the pulling operation of the trigger 6 to return to the home position HP at the front end position.
The home position HP and the rear end position RP will be described as the axial position of the pulling head 30, but the ball screw shaft 36, the jaw case 32, and the jaw 29 also correspond to the home position HP and the rear end position RP. There is.

(Blind rivet)
FIG. 3 is a longitudinal sectional view of a front portion of the fastening mechanism of the electric blind rivet fastening device of FIG. 1 and shows a state in which the blind rivet is attached to the nose 7.
The blind rivet is held by the nose piece 31 of the electric blind rivet fastening device 1. The blind rivet includes a rod-shaped mandrel M and a hollow cylindrical rivet body R. The rivet body R includes a cylindrical sleeve S and a flange F having a larger diameter than the cylindrical sleeve formed at one end of the cylindrical sleeve. The mandrel M is a rod-like body that extends through the rivet body and extends from the flange. The mandrel M has a shaft portion J that has a portion that passes through the flange of the rivet body R and is gripped by the nose 7 and is larger than the inner diameter of the cylindrical sleeve S And a mandrel head H formed in a diameter and arranged to extend from the other end of the cylindrical sleeve. The blind rivet is held by the blind rivet fastening device with the grip portion of the mandrel shaft portion J inserted into the nose 7 of the blind rivet fastening device 1 and the rivet body R and the mandrel head H coming out of the nose.

  The blind rivet held by the blind rivet fastening device 1 is inserted into the mounting hole of the fastened member until the sleeve S of the rivet main body R contacts the fastened member such as the vehicle body panel and mounting parts. Next, the mandrel shaft portion is strongly pulled out by the blind rivet fastening device 1, and the mandrel head H expands and deforms a part of the sleeve S of the rivet body R, and between the expanded and deformed sleeve portion and the flange F The to-be-fastened member is strongly held between the two. The rivet main body R is fastened to the fastened member by a plurality of fastened members such as the vehicle body panel and the parts being firmly clamped between the flange portion and the sleeve portion where the expanded member is deformed. Is fixed. In general, the blind rivet is made of a metal material such as steel or aluminum. In the blind rivet after fastening, it is necessary to collect the broken mandrel shaft.

(Nose)
The structure and operation of the blind rivet fastening mechanism 2 for fastening the blind rivet will be described with reference to FIGS. The nose 7 occupies the front portion of the blind rivet fastening mechanism 2 in front of the collection container 10.
As shown in FIG. 3, the nose 7 has a hollow shaft center portion, receives and holds the mandrel M of the blind rivet, and can further send the broken mandrel shaft portion J to the collection container 10. It is like that. The nose 7 includes a jaw 29 that grips the mandrel shaft portion J, a jaw case 32 that surrounds the jaw 29, and an axial direction of the blind rivet fastening mechanism 2 so as to be integrated with the jaw case 32 and retract the jaw 29 backward. And a pulling head 30 that is movable.

  The mandrel shaft portion J gripped by the jaw 29 is strongly pulled by the rearward movement of the pulling head 30, and the mandrel head H expands and deforms a part of the sleeve S of the rivet main body R, and the expansion and deformation thereof occurs. The fastened member is firmly held between the sleeve portion and the flange F, the mandrel shaft portion J is broken at the breakable portion, and the blind rivet is fastened to the fastened member.

  FIG. 4 is a longitudinal sectional view of the front portion of the nose 7 of the fastening mechanism of FIG. 3, showing a state where the broken mandrel shaft portion of the blind rivet remains in the nose portion. The nose 7 has a nose piece 31 at the tip, and a cylindrical nose housing 33 extending from the nose piece 31 toward the rear tool housing 27. A cylindrical pulling head 30 is accommodated inside the nose housing 33 so as to be slidable in the axial direction (front-rear direction) with respect to the nose housing 33. The jaw 29 is disposed so that the tip thereof is adjacent to the rear end of the nosepiece 31, is formed in a tapered shape toward the nosepiece 31, and is accommodated in the tapered cavity of the jaw case 32.

When the jaw case 32 is pulled backward, a force is applied to the inclined surface of the tapered portion so as to be centripetal to the shaft center, and the shaft portion J of the mandrel M of the blind rivet held in the cavity of the shaft center of the jaw 29 is applied. The gripping force is strengthened.
The jaw 29 is divided into two to three in the circumferential direction in the cylindrical jaw case 32, and the jaw case 32 is combined with a hollow cylindrical body having a hollow axial center in the jaw case 32. The mandrel M of the blind rivet inserted from is received and held so that the shaft portion J of the mandrel M does not fall off.

  A hollow cylindrical jaw pusher 35 is disposed behind the jaw 29 and presses the jaw 29 forward. A jaw pusher spring 42 is disposed between the jaw pusher 35 and the pulling head 30 to press the jaw pusher 35 forward.

  In the embodiment of the present invention, the pulling head 30 is integral with a jaw case 32 that surrounds and supports the jaw 29, and is arranged with its axis center aligned with the nose housing 33, and with respect to the nose housing 33. It is arranged to be slidable in the axial direction. The pulling head 30 can retract the jaw 29 from the front end position to the rear end position, and can return the jaw 29 from the rear end position to the front end position.

  An O-ring 46 and a steel ball 47 are provided at the inlet portion of the nosepiece 31 so as to obstruct a part of the hollow passage. It is prevented from being discharged from the piece 31 to the outside.

The pulling head 30 and the jaw case 32 are slidable in the axial direction in the nose housing 33.
As will be described later with respect to the second clutch, the pulling head 30 cannot rotate in the forward rotation direction of the spindle 14 but rotates in the reverse direction when a reverse rotation force of a certain level or more is applied.

  Returning to FIG. 3, the pulling head 30 is fixed to the ball screw shaft 36 at the rear thereof. The ball screw shaft 36 is a cylindrical member and extends in the axial direction inside the mast housing 34 fixed to the tool housing 27. A cylindrical tail 45 narrower than the ball screw shaft 36 is connected to the rear side in the axial direction of the ball screw shaft 36. The tail 45 extends rearward along the axial center portion of the spindle 14. The tail 45, the ball screw shaft 36 and the pulling head 30 move linearly, and the jaw 29 is retracted to the rear of the nose 7 and returned to the front of the nose 7.

  The spindle 14 is connected to a ball screw nut 44 via a first clutch as will be described later. A ball screw shaft 36 is disposed in the axial center portion of the ball screw nut 44. The ball screw nut 44 has an internal thread. An external screw of the ball screw shaft 36 is screwed into the internal screw.

  The rotation of the spindle 14 is transmitted to the ball screw nut 44. The forward rotation of the spindle 14 that does not move in the axial direction is converted into a backward movement that retracts the ball screw shaft 36 backward, and the reverse rotation of the spindle 14 is converted into a forward movement that returns the ball screw shaft 36 forward. When the spindle 14 rotates in the forward direction, the ball screw shaft 36 and the pulling head 30 are retracted, and the mandrel shaft portion J of the plinth rivet is gripped by the jaw 29 and pulled strongly to fasten the plinth rivet.

  As shown in FIG. 3, the axial centers of the jaw 29, the jaw pusher 35, the pulling head 30, the ball screw shaft 36, and the tail 45 are continuous from the inlet of the nose 7 to the inlet of the collection container 10. It is formed as a hollow passage. As a result, the shaft portion of the mandrel M is inserted into the jaw 29, and the broken mandrel shaft portion 43 is fed into the collection container 10 as indicated by the arrow 48 in FIG. The broken mandrel shaft portion is fed by a method in which the broken mandrel shaft portions successively fed to the hollow passage push out the previous broken mandrel shaft portion.

(clutch)
In the embodiment of the present invention, the pulling head 30 is controlled to move between the home position HP located at the front end portion and the rear end position RP where the mandrel is broken. However, a clutch mechanism is provided to prevent abnormal torque when the pulling head 30 moves out of the range between the home position HP and the rear end position RP due to some abnormality. FIG. 5 is a perspective view showing a portion of the nose 7 and shows the internal structure with the mast housing 34 and the nose housing 33 removed.

A first clutch including a spindle clutch 61 and a nut clutch 62 is provided between the spindle 14 and the ball screw nut 44. When the first clutch reaches the rear end position RP by pulling of the pulling head 30, the engagement between the spindle clutch 61 and the nut clutch 62 is released so that the rotation is not transmitted from the spindle 14 to the ball screw nut 44. The head 30 is prevented from being pulled too much.
A second clutch including a rear clutch 63 and a front clutch 64 is provided in front of the ball screw shaft 36. The second clutch allows the front clutch 64 and the pulling head 30 to rotate together with the ball screw nut 44 when the pulling head 30 moves forward to the home position HP at the front end, and abnormal torque is applied to the pulling head 30 and the like. To prevent.

(First clutch)
FIG. 6 is a perspective view of a portion of the first clutch including the spindle clutch 61 and the nut clutch 62, and shows the internal structure with the tool housing 27 and a part of the mast housing 34 removed.
A spindle clutch 61 is provided adjacent to the inside of the cylindrical spindle 14. The spindle clutch 61 cannot rotate with respect to the spindle 14, but can slide in the axial direction and is pressed in the direction of the nut clutch 62 by the spindle clutch spring 65. The spindle clutch 61 has a cylindrical cylindrical portion and a flange portion at the end of the cylindrical portion. The flange portion has a fan-shaped fan-shaped portion when viewed from the axial direction.

  A nut clutch 62 is provided integrally with the ball screw nut 44. The nut clutch 62 has a fan-shaped portion, and this fan-shaped portion has a shape that can enter a portion of the spindle clutch 61 where there is no fan-shaped portion. That is, the fan-shaped portion of the spindle clutch 61 and the fan-shaped portion of the nut clutch 62 have complementary shapes. When the pulling head 30 is in a position in front of the rear end position RP, the fan-shaped portion of the spindle clutch 61 and the fan-shaped portion of the nut clutch 62 are engaged with each other, and the rotation of the spindle clutch 61 is transmitted to the nut clutch 62. .

  A tail 45 is coupled to the rear end of the ball screw shaft 36. A tail convex portion 45 </ b> A is integrally provided on the shaft portion of the tail 45. When the pulling head 30 moves backward, the tail 45 also moves backward. The tail convex portion 45A moves rearward inside the spindle clutch 61, and when it reaches the inner end surface of the spindle clutch 61, the tail convex portion 45A pushes the end surface against the pressing force of the spindle clutch spring 65 and moves rearward ( (In the direction of arrow 41). As a result, the engagement between the spindle clutch 61 and the nut clutch 62 is released.

  When the trigger 6 is pressed while the pulling head 30 is at the home position HP, the electric motor 13 rotates in the forward direction (in the direction of the arrow 39). The rotation of the electric motor 13 is transmitted to the spindle 14 and from the spindle clutch 61 fixed integrally with the spindle 14 to the nut clutch 62, and the ball screw nut 44 integrated with the nut clutch 62 rotates, and the ball screw shaft 36. Moves in the direction of arrow 41 (backward).

  When the pulling head 30 comes to the rear end position RP, the tail convex portion 45A of the tail 45 integral with the ball screw shaft 36 hits the inner end face of the spindle clutch 61. The spindle clutch 61 is pushed by the tail convex portion 45 </ b> A and moves in the direction of the arrow 41 against the pressing force of the spindle clutch spring 65. The engagement between the spindle clutch 61 and the nut clutch 62 is released. As a result, even if the ball screw nut 44 and the spindle clutch 61 rotate, the nut clutch 62 does not rotate. The movement of the ball screw shaft 36 in the direction of the arrow 41 stops, and the pulling operation of the pulling head 30 stops.

  Even if the pulling head 30 moves backward to the predetermined rear end position RP due to some abnormality and the forward rotation of the spindle 14 does not stop, the engagement between the spindle clutch 61 and the nut clutch 62 is released at the rear end position RP. Thus, the rotation is not transmitted from the spindle clutch 61 to the nut clutch 62, and the pulling head 30 can be prevented from being pulled too much.

(Second clutch)
7A to 7C are perspective views of the second clutch portion including the rear clutch 63 and the front clutch 64, and show the internal structure with the nose housing 33 and a part of the mast housing 34 removed. FIG. 7A shows a state where the pulling head 30 is at the rear end position RP and starts to return to the home position HP. FIG. 7B shows a state where the pulling head 30 has returned to the home position HP and the ball screw shaft 36 has reached the front end. FIG. 7C shows a state where the engagement of the front clutch 64 and the rear clutch 63 is released at the home position HP and the pulling head 30 stops moving.

  Refer to FIG. 7A. When the ball screw shaft 36 is behind the front end, the end surface of the tail 45 is not in contact with the nut clutch 62, and when the ball screw nut 44 rotates, the ball screw shaft 36 moves in the axial direction. When the ball screw shaft 36 reaches the front end portion, the end surface of the tail 45 contacts the nut clutch 62, so that the ball screw shaft 36 does not move further forward. Since the outer screw of the ball screw shaft 36 is engaged with the inner screw of the ball screw nut 44, the ball screw shaft 36 rotates together with the ball screw nut 44.

  The rear clutch 63 is a cylindrical member that surrounds the pulling head 30 and is arranged around the pulling head 30 so as to be movable by a predetermined distance in the axial direction. A saw blade is provided on the front side of the rear clutch 63. One surface of the sawtooth is parallel to the axial direction, and the other surface is a slope. Further, the rear clutch 63 has a rear clutch convex portion 63 </ b> A that contacts the mast housing 34 and acts as a rotation stopper on the outer peripheral portion of the rear clutch 63. The rear clutch 63 is pressed against the front clutch 64 by the rear clutch spring 66.

  A cylindrical front clutch 64 is provided on the front side of the rear clutch 63 around the pulling head 30. The front clutch 64 is coupled so as to rotate integrally with the pulling head 30. The front clutch 64 has a sawtooth on the rear side facing the rear clutch 63. One surface of the sawtooth of the front clutch 64 is parallel to the axial direction, and the other surface is a slope, and engages with the sawtooth of the rear clutch 63.

When the front clutch 64 rotates forward in the direction opposite to the arrow 39R, the saw-tooth of the rear clutch 63 and the saw-tooth of the front clutch 64 do not slip because the axial surfaces of the saw-tooth are engaged. Since the rear clutch 63 is stopped by the rear clutch convex portion 63A, the front clutch 64 and the pulling head 30 cannot rotate.
Accordingly, during the fastening operation in which the spindle 14 rotates forward and the pulling head 30 moves backward, the pulling head 30 is stopped from rotating.

When the front clutch 64 rotates in the reverse direction in the direction of the arrow 39R, the sawtooth of the rear clutch 63 and the sawtooth of the front clutch 64 mesh with the slope of the sawtooth. The rear clutch 63 slides in the backward direction indicated by the arrow 41 against the pressing force of the rear clutch spring 66. Therefore, the reverse rotation of the front clutch 64 is not transmitted to the rear clutch 63, and the front clutch 64 and the pulling head 30 are rotated.
Accordingly, if the spindle 14 does not stop rotating even when the pulling head 30 returns to the home position HP, the pulling head 30 and the front clutch 64 rotate together with the spindle 14 in the direction of the arrow 39R, and the rear clutch 63 moves backward. Thus, the engagement with the front clutch 64 is released, and the rotation of the front clutch 64 is allowed.

  As shown in FIG. 7A, when the pulling operation of the trigger 6 is released when the pulling head 30 is at the rear end position RP, the electric motor 13 rotates reversely in the direction of the arrow 39R, and the rotation of the motor 13 is rotated from the spindle clutch 61 to the nut. The ball screw nut 44, which is transmitted to the clutch 62 and rotates integrally with the nut clutch 62 in the direction of the arrow 39R, and cannot rotate due to the engagement of the rear clutch 63 and the front clutch 64, is indicated by the arrow 41R. Move in the direction (forward direction). The tail 45 is not in contact with the nut clutch 62.

  Refer to FIG. 7B. When the pulling head 30 returns to the home position HP and the ball screw shaft 36 reaches the front end, the end surface of the tail 45 abuts on the nut clutch 62. The ball screw shaft 36 does not move further in the direction of the arrow 41R. The ball screw shaft 36 begins to rotate with the ball screw nut 44. The rotation of the ball screw shaft 36 is transmitted to the front clutch 64 via the pulling head 30.

  Refer to FIG. 7C. The rear clutch protrusion 63A contacts the mast housing 34, and the rear clutch 63 does not rotate. When the front clutch 64 starts to rotate, the rear clutch 63 cannot be rotated by the mast housing 34. Therefore, the front clutch 64 moves in the direction of the arrow 41 (rearward direction) against the pressing force of the rear clutch spring 66, and the front clutch 64 The engagement of the rear clutch 63 is released. The pulling head 30, the jaw case 32, and the front clutch 64 do not move forward but rotate.

  If the reverse rotation of the spindle 14 is not stopped even if the pulling head 30 returns to the home position HP due to some abnormality, the pulling head 30, the jaw case 32, and the front clutch 64 rotate, and the rear clutch 63 moves backward. Move to. Since the front clutch 64 rotates without hindering the rotation of the rear clutch 63, the rotation of the ball screw shaft 36 is allowed, and the pulling head 30 can be prevented from coming forward from the home position HP.

(Operation control of fastening device)
By the pulling operation of the trigger 6 and the releasing operation thereof, the power transmission / control unit 11 causes the electric motor 13 to rotate forward, stop, and reversely rotate. When the motor shaft of the electric motor 13 rotates around the axis, the second shaft 18 rotates around the axis by the motor gear 15 and the rear gear 19, and when the second shaft 18 rotates, the front gear 21 and the spindle gear 17 The spindle 14 rotates around the axis. The ball screw nut 44 rotates and the ball screw shaft 36 moves in the axial direction. Pull the pulling head 30 backward and return it forward.

  FIG. 8 is a block diagram of the power transmission / control unit. The control circuit 55 shown in FIG. 8 controls the electric motor 13 in response to the on / off signal of the trigger switch 49 operated by the pulling operation of the trigger 6 and the releasing operation thereof, and the pulling head 30 of the nose 7 is moved. The blind rivet fastening mechanism 2 is moved from the front end home position HP to the rear end position RP where the mandrel shaft portion of the blind rivet is broken, stopped at the rear end position RP, and advanced from the rear end position RP to the front end position home position HP. Let

A description will be given of how the electric motor 13, the spindle 14, the pulling head 30, the jaw 29, and the like are controlled by the control means by operating the trigger 6 and detecting the number of rotations of the electric motor 13.
The rotation speed of the electric motor 13 is detected by the Hall element 13A, and the rotation speed signal (R) of the electric motor 13 is input to the control circuit 55 serving as control means by the electronic circuit 13B. An on / off signal of the trigger switch 49 that is turned on / off by the pulling operation of the trigger 6 and its release is input to the control circuit 55. The control circuit 55 is provided with a signal processing unit 55A. The signal processing unit 55A receives the rotation speed signal (R) of the electric motor 13 and the on / off signal (T) of the trigger switch 49, and receives the normal rotation signal (S _N ), stop signal (S _S ), reverse A rotation signal (S _R ) is output. With these signals, the electric motor 13 is rotated forward, stopped, and reversely rotated.

Further, the control circuit 55 is provided with a driver 55B. Upon receiving the forward rotation signal (S _N ), the stop signal (S _S ), and the reverse rotation signal (S _R ) from the signal processing unit 55A, the driver 55B causes the electric motor 13 to rotate forward, stop, and reverse The electric power supplied from the battery 51 is controlled so as to rotate. The signal processing unit 55A and the driver 55B constituting the control circuit 55 are disposed in a space in the handle 3, for example.

Before electric power is supplied from the battery 51 to the electric motor 13, the pulling head 30 is located at the home position HP (position in FIG. 3) on the front end side of the blind rivet fastening mechanism 2. When the pulling head 30 is at the home position HP, the rotation speed of the electric motor 13 is set to zero. When the ON signal is not output from the trigger switch 49 of the trigger 6 (or the OFF signal is output), the pulling head 30 is at the home position HP when the rotation speed of the electric motor 13 is zero. Even if electric power is supplied from the battery 51 to the electric motor 13, the electric motor 13 stops operating unless the trigger 6 is operated, and the pulling head 30 is at the home position HP. Based on the OFF signal (T _OFF ) from the trigger switch 49 of the trigger 6 and the number of revolutions of the electric motor 13, the control circuit recognizes that the fastening device 1 is at the home position HP, and generates a stop signal (S _S ). Output.

When the trigger 6 is pulled with the electric motor 13 rotating at zero, an ON signal (T _ON ) is output from the trigger switch 49 and the signal processing unit of the control circuit 55 provided in the electric blind rivet fastening device 1. 55A outputs a normal rotation signal (S _N ) for rotating the electric motor 13 in the normal direction. Upon receiving the forward rotation signal (S _N ), the driver 55B sends the electric power from the battery 51 to the electric motor 13 to cause the electric motor 13 to rotate forward.

  When the electric motor 13 is rotated forward, it is transmitted to the spindle 14 through the motor gear 15, the rear gear 19, the second shaft 18, the front gear 21, and the spindle gear 17, so that the spindle 14 rotates forward. By the forward rotation of the spindle 14, the ball screw shaft 36 (FIG. 3) is retracted in the axial direction, and the pulling head 30 is retracted in the axial direction from the home position HP at the front end in a predetermined length (length for breaking the mandrel shaft portion). Let By this backward movement, the jaw 29 is retracted from the position of the front end, and the shaft portion J of the mandrel M of the blind rivet held by the jaw 29 is retracted.

  This backward pulling is so strong that the mandrel shaft portion J is broken, and the mandrel head H expands and deforms a part of the sleeve S of the rivet body R, and the expanded and deformed sleeve portion and the rivet body R The fastened member is strongly sandwiched between the flange F of the two. The rivet main body R is fastened to the fastened member by a plurality of fastened members such as the vehicle body panel and the parts being firmly clamped between the flange portion and the sleeve portion where the expanded member is deformed. Is fixed.

When the electric motor 13 rotates forward, the second shaft 18 rotates reversely by the motor gear 15 and the rear gear 19. When the second shaft 18 rotates in the reverse direction, the spindle 14 rotates forward and the pulling head 30 moves in the axial direction. The axial position of the pulling head 30 is obtained by the number of rotations of the electric motor 13 by the Hall element 13A. The rear end of the pulling head 30 behind the position where the mandrel shaft portion J breaks due to the rotation of the electric motor 13 at a predetermined rotation number (the rotation number corresponding to the moving length of the pulling head 30 where the mandrel shaft portion is broken). When moving to the position RP, a predetermined rotation number of the brushless motor 13 is counted by a rotation number signal from the electronic circuit 13B. Since the trigger 6 remains pulled, an on signal (T _ON ) is output from the trigger switch 49.

When the predetermined number of rotations of the electric motor 13 is counted with the on signal (T _ON ) being output from the trigger switch 49, the pulling head 30 is at the rearmost rear end position RP. At this time, the signal processing unit 55A of the control circuit 55 receives the ON signal (T _ON ) from the trigger switch 49 and the count of the predetermined number of revolutions of the electric motor 13, and outputs a stop signal. The driver 55B receives the stop signal (S _S ) and stops the rotation of the electric motor 13 (there is a stop by a brake operation, a stop by regenerative braking, or the like). When the electric motor 13 stops, the rotation of the spindle 14 also stops, and the pulling head 30 (jaw 29) stops at the rear end position RP.

When the electric motor 13 stops rotating and the pulling head 30 is at the rear end position RP (that is, an ON signal (T _ON ) is output from the trigger switch 49 of the trigger 6 and the predetermined number of rotations of the electric motor 13 is counted. In the state), when the pulling operation of the trigger 6 is released, the ON signal (T _ON ) from the trigger switch 49 of the trigger 6 disappears (or the OFF signal is output). The signal processing unit 55A of the control circuit 55 receives the OFF signal (T _OFF ) from the trigger switch 49 and the count of the predetermined number of rotations of the electric motor 13, and outputs a reverse rotation signal (S _R ). The driver 55B that has received the reverse rotation signal (S _R ) rotates the electric motor 13 in the reverse direction. Due to the reverse rotation of the electric motor 13, the spindle 14 also rotates reversely, the ball screw shaft 36 moves forward, and the pulling head 30 is moved from the rear end position RP to the front end home position HP.

As a result, when the pulling head 30 returns to the home position HP, the rotational speed of the electric motor 13 is subtracted and the rotational speed becomes zero. The control circuit 55 receives the OFF signal (T _OFF ) from the trigger switch 49 and the rotation speed of the electric motor 13 and outputs a stop signal (S _S ).
When the pulling head 30 is at the home position HP, the control circuit 55 puts the electric motor 13 into a non-operating state unless the trigger 6 is operated. Therefore, the electric motor 13 stops operating, and the pulling head 30 remains at the home position HP.

If the pulling operation of the trigger 6 is released while the electric motor 13 does not reach the predetermined rotation speed during the normal rotation, the signal processing unit 55A of the control circuit 55 causes the rotation of the electric motor 13 to rotate. In response to the number signal (R) and the off signal (T _OFF ) of the trigger switch 49, a reverse rotation signal (S _R ) is sent to the driver 55B, and the driver 55B rotates the electric motor 13 in the reverse direction. The reverse rotation of the electric motor 13 is continued until the count of the number of rotations of the electric motor 13 becomes zero, and the pulling head 30 (jaw 29) is returned to the home position HP on the front end side of the blind rivet fastening mechanism 2. Accordingly, even if the blind rivet fastening operation is interrupted for some reason, the pulling head 30 is returned to the home position HP. Therefore, when the blind rivet fastening operation is to be interrupted, the blind rivet fastening operation can be easily interrupted by releasing the trigger 6 pulling operation.

As described above, even if the pulling head 30 moves back to the predetermined rear end position RP due to some abnormality and the forward rotation of the spindle 14 does not stop, the engagement of the first clutch is released at the rear end position RP. Further, pulling of the pulling head 30 can be prevented.
Even if the pulling head 30 returns to the home position HP due to some abnormality, even if the reverse rotation of the spindle 14 is not stopped and an abnormal torque is applied, the second clutch slips and the pulling head 30 is reversed together with the spindle 14. It can be prevented that the pulling head 30 moves forward from the home position HP by rotating.
In addition, in consideration of a case where the pulling head 30 has not returned to the hope position HP due to some abnormality, the spindle 14 may always be rotated in the reverse direction so that the pulling head 30 returns to the home position HP. In this case, the second clutch slips at the home position HP, and the pulling head 30 is positioned at the home position HP.

According to the embodiment of the present invention, the volume of the recovery container for recovering the broken mandrel can be increased.
Even when an abnormality occurs, it is possible to avoid applying an abnormal force due to an overstroke.

DESCRIPTION OF SYMBOLS 1 Electric blind rivet fastening device 2 Blind rivet fastening mechanism 3 Handle 5 Battery holding part 6 Trigger 7 Nose 9 Motor part 10 Recovery container 10A Cover 11 Power transmission / control part 13 Electric motor 13A Hall element 13B Electronic circuit 14 Spindle 15 Motor gear 17 Spindle Gear 18 second shaft 19 rear gear 21 front gear 27 tool housing 29 jaw 30 pulling head 32 jaw case 31 nose piece 33 nose housing 34 mast housing 35 jaw pusher 36 ball screw shaft 39 arrow 41 arrow 42 jaw pusher spring 43 breaking mandrel Shaft 44 Ball screw nut 45 Tail 46 O-ring 47 Steel ball 48 Arrow 49 Trigger switch 51 Battery 55 Control circuit 55A Signal Processing section 55B driver 61 spindle clutch 62 nut clutch 63 Rear clutch 63A rear clutch protrusive portion 64 front clutch 65 spindle clutch spring 66 rear clutch spring F flange H mandrel head J shaft M mandrel R rivet body S cylindrical sleeve

Claims (11)

By pulling the mandrel of a blind rivet comprising a mandrel and a rivet body in the axial direction, the sleeve of the rivet body is deformed to expand the diameter, and the rivet body is formed by the expanded sleeve portion and the flange of the rivet body. Is a blind rivet fastening device that fastens the attached member and breaks the mandrel,
An electric motor disposed at one end;
Power transmission means for transmitting rotation of the electric motor;
A spindle that is arranged in front of the electric motor and that is rotated by being transmitted power by the power transmission means;
A ball screw nut adjacent to the spindle and connected to the spindle for rotation;
A ball screw shaft provided at a central portion in the axial direction of the ball screw nut and moving in the axial direction by rotation of the ball screw nut;
A pull-in means connected to the ball screw shaft and gripping and pulling the shaft portion of the mandrel;
A rotational speed detection element for detecting the rotational speed of the electric motor;
A trigger provided on the handle,
The forward rotation of the electric motor is controlled by the pulling operation of the trigger and the rotation speed of the electric motor, and the reverse rotation and the stop are controlled by releasing the trigger pulling operation and the rotation speed of the electric motor. Control means for controlling
A blind rivet fastening device comprising:   2. The electric blind rivet fastening device according to claim 1, wherein a recovery container that accommodates a portion of the broken mandrel shaft portion is disposed between the electric motor and the spindle. The electric blind rivet fastening device according to claim 1 or 2, wherein the pull-in means is
A pulling head that moves in the axial direction by the axial movement of the ball screw shaft;
A jaw case that is disposed integrally with the pulling head adjacent to the pulling head and has an inner peripheral surface with a smaller inner diameter toward the front end;
A jaw that is disposed within the jaw case and has an outer peripheral surface that abuts against an inner peripheral surface of the jaw case;
A blind rivet fastening device comprising: a nosepiece disposed adjacent to the jaw and having an opening through which the shaft portion of the mandrel passes. The electric blind rivet fastening device according to claim 1 or 3, wherein the power transmission means is
A motor gear coupled to the electric motor; a rear gear provided below the motor gear and engaged with the motor gear; a spindle gear engaged with the spindle; and a spindle gear provided below the spindle gear and engaged with the spindle gear. A blind rivet fastening device comprising: a front gear, and a second shaft that is provided below the collection container and integrally couples the rear gear and the front gear.   The electric blind rivet fastening device according to any one of claims 1 to 4, wherein the electric motor is a brushless motor.   The electric blind rivet fastening device according to any one of claims 1 to 5, wherein the rotational speed detection element is a Hall element. The blind rivet fastening device according to any one of claims 1 to 6,
A spindle clutch having a cylindrical portion and a fan-shaped portion, movable in the axial direction with respect to the spindle, and rotating integrally with the spindle;
A first clutch that includes a fan-shaped portion that engages with the fan-shaped portion of the spindle clutch and includes a nut clutch integrally coupled to the ball screw nut;
The blind rivet fastening device, wherein the first clutch can release the engagement between the spindle clutch and the nut clutch, and can prevent the rotation of the spindle from being transmitted to the ball screw nut.   8. The electric blind rivet fastening device according to claim 7, wherein when the ball screw shaft reaches the rear end portion in the axial direction, a tail protrusion of a cylindrical tail integrally coupled to the rear end portion of the ball screw shaft. A blind rivet fastening device in which the portion pushes the inner end face of the spindle clutch rearward in the axial direction to disengage the fan-shaped portion of the spindle clutch from the fan-shaped portion of the nut clutch. The blind rivet fastening device according to any one of claims 3 to 8,
A rear clutch that is cylindrical, has a sawtooth at the front end, is axially movable around the pulling head, and is non-rotatable;
It is cylindrical and has a saw blade that engages with the saw blade of the rear clutch at a rear end portion, is disposed in front of the rear clutch, is disposed around the pulling head, and is integrally coupled with the pulling head. A second clutch including a front clutch ,
A blind rivet fastening device in which the spindle is rotated in the reverse direction, the second clutch is slipped at a home position of the pulling head, and the pulling head is positioned at the home position . The electric blind rivet fastening device according to claim 9,
The saw blade of the rear clutch has one surface parallel to the axial direction of the rear clutch and the other surface inclined with respect to the axial direction.
The blind rivet fastening device, wherein the saw blade of the front clutch is shaped to engage with the saw blade of the rear clutch.   11. The electric blind rivet fastening device according to claim 10, wherein when the ball screw shaft reaches a front end portion, the ball screw shaft does not move in the axial direction but rotates together with the ball screw nut, and the front clutch. Is a blind rivet fastening device in which the rear clutch is moved backward in the axial direction and the front clutch is rotated.

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