HK1113666B - Bolt or nut tightening device - Google Patents

Description

Bolt or nut fastening device

Technical Field

The present invention relates to a bolt or nut fastening device formed by a combination of a fastening assisting unit including an engaging portion that engages with a bolt or nut, a reaction force receiving member, and a fastening torque measuring unit, and an input mechanism connected to the fastening assisting unit.

The applicant has previously proposed a bolt or nut fastening device in which a fastening torque measuring unit is connected to an output shaft of a power fastening machine, and a socket with a reaction force receiving member is connected to an output side of the fastening torque measuring unit (japanese patent application laid-open No. 2006-21272).

In the above bolt or nut tightening apparatus, the power tightening machine as the input means may use an existing device, and the actual tightening torque may be displayed by the tightening torque measurement unit.

However, the fastening torque measuring means is provided with a strain gauge on an outer output shaft of the power fastening machine, a cylindrical body concentrically connected to the outer output shaft, a circuit board for converting the strain gauge into a corresponding fastening torque, a display unit for displaying the fastening torque, and a battery on the outside of the cylindrical body, and the circuit board, the display unit, and the battery are covered with a cylindrical case concentric with the cylindrical body.

In order to accommodate the circuit board, the display unit, and the battery in the annular space formed between the cylindrical case and the inner cylindrical body, the cylindrical case must have an inner diameter and a length that are sufficient for these components.

Further, the cylindrical case serves to protect the structural members of the fastening torque measuring unit, and is required to have high rigidity in a work environment where there is a high risk of collision or falling with a work piece, such as at a construction site.

Therefore, the tightening torque measuring unit has an increased outer diameter, an increased length, and an increased weight.

In addition, the tightening torque measuring unit itself does not incorporate a speed reduction mechanism, and the input mechanism requires an expensive large-sized power tightening machine equipped with a speed reduction mechanism for large-sized fastening of a large bolt or nut necessary for managing the tightening torque.

If a large tightening torque measuring unit is connected to a large power tightening machine to form the tightening machine, there is a difficulty in the mobility and ease of use of the tightening machine.

Further, the torque display unit of the tightening torque measuring means is configured in such a manner that numerical values are arranged along the axial direction of the cylindrical housing, and there is a problem that it is difficult for an operator who operates the power tightening machine to see.

The invention provides a bolt or nut tightening device which can use a conventional low-cost and small-sized power tightening machine or a manual wrench as an input mechanism, includes a planetary gear device, can suppress the increase in the outer diameter and length, has excellent maneuverability and is easy to use, and a tightening torque display section is easy to see.

A bolt or nut fastening device according to the present invention is a bolt or nut fastening device including a fastening assistance unit including an outer shaft and an inner shaft that are connected to a planetary gear reduction device, are concentrically arranged, and are capable of rotating in opposite directions, a reaction force receiving member that protrudes laterally from the outer shaft, an engagement portion that engages with a counterpart bolt or nut provided on the inner shaft, and an input mechanism that is connected to the planetary gear reduction device, and a fastening torque measurement unit provided on the outer shaft, the fastening torque measurement unit including: a deformation sensor such as a deformation gauge attached to a recessed portion formed on an outer periphery of the outer shaft; an installation cylinder fitted to the outer shaft and rotatably installed integrally with the outer shaft; a circuit board for converting the deformation of the outer shaft detected by the deformation sensor into a fastening torque; a display part for displaying the fastening moment; a battery; and a case that houses the circuit board, the display unit, and the battery, the case protruding in the same direction as the reaction force receiving member from an outer peripheral portion of the mounting cylinder, being formed to have a size covered by an outer contour of the reaction force receiving member and located at a position covered by the reaction force receiving member when viewed from a front end side of the engaging portion, the mounting cylinder covering the deformation sensor by covering a recessed portion of the outer shaft, and the reaction force receiving member having a function of protecting the case from an external impact.

In the bolt or nut fastening device according to the present invention, the display unit is preferably configured such that numerical values are arranged in the protruding direction of the housing.

In the bolt or nut fastening device according to the present invention, the housing is preferably provided so as to be rotatable about an axis orthogonal to the axis of the outer shaft.

In one embodiment of the bolt or nut tightening apparatus according to the present invention, the input mechanism is a power tightening machine having two output shafts, an inner output shaft and an outer output shaft, which are concentric with each other, and the input receiving portion provided in the tightening assist unit includes a first coupling member that is integrally rotatable and detachably coupled to an outer shaft of the tightening assist unit and an outer output shaft of the power tightening machine, and a second coupling member that is integrally rotatable and detachably coupled to an input shaft of a system for rotationally driving the engagement portion of the tightening assist unit and the inner output shaft of the power tightening machine.

In one embodiment of the bolt or nut tightening apparatus according to the present invention, the input mechanism is a power tightening machine having 1 output shaft, and the input receiving portion provided in the tightening assist unit has a coupling member that is integrally rotatable and detachably couples an input shaft of a system for rotationally driving the engagement portion of the tightening assist unit and the output shaft of the power tightening machine.

In one embodiment of the bolt or nut tightening device according to the present invention, the input mechanism is a manual wrench, and the input receiving portion provided in the tightening assist unit includes a coupling member that is integrally rotatable and detachably couples an input shaft of a system for rotationally driving the engagement portion of the tightening assist unit and an output shaft of the manual wrench.

In one embodiment of the bolt or nut tightening device according to the present invention, the input mechanism is a manual wrench, the input receiving portion provided in the tightening assist unit includes a coupling member that is integrally rotatable and detachably coupled to an input shaft of a system for rotationally driving the engagement portion of the tightening assist unit and an output shaft of the manual wrench, and a one-way clutch that is attached to the tightening assist unit and allows rotation of the manual wrench in a desired direction and prevents rotation in the opposite direction.

Drawings

FIG. 1 is a cross-sectional view of a fastening device of a first embodiment of the present invention;

fig. 2 is a sectional view of the fastening device of the first embodiment with the input receiving portion and the input mechanism separated;

FIG. 3 is an exploded perspective view of the fastening aid unit;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 1;

FIG. 6 is a cross-sectional view of a fastening device of a second embodiment;

FIG. 7 is a cross-sectional view of the fastening device of the second embodiment with the input receiving portion and the input mechanism separated;

FIG. 8 is a cross-sectional view of a fastening device of a third embodiment;

fig. 9 is a sectional view of the fastening device of the third embodiment with the input receiving portion and the input mechanism separated.

Detailed Description

The present invention will be described in detail with reference to the embodiments shown in the drawings.

< first embodiment (FIGS. 1 to 4) >

The bolt or nut fastening device includes a fastening assisting unit 1 having an engaging portion 6 for engaging with a bolt or nut, and an input mechanism 9 connected to the fastening assisting unit 1.

The fastening assisting unit 1 includes: a planetary gear reduction unit 2 having 2 output shafts and 1 input shaft provided in a tubular case 20, an outer shaft 4 and an inner shaft 3 connected to the planetary gear reduction unit 2 and projecting concentrically forward of the case 20, an engagement portion 6 engaged with a counterpart bolt or nut (hereinafter, represented by a "nut") projecting at the tip of the inner shaft 3, an input receiving portion 8 for detachably connecting an input mechanism 9 to the planetary gear reduction unit 2, a tightening torque measuring unit 7 attached to the outer shaft 4 and displaying a tightening torque, and a reaction force receiving member 5 attached to the outer shaft 4.

As shown in fig. 2, the planetary gear reduction device 2 is composed of a first planetary gear mechanism 21 on the input side and a second planetary gear mechanism 22 on the output side.

The first planetary gear mechanism 21 is composed of a first sun gear 21a, a first planetary gear 21c, first internal teeth 21b formed on the inner surface of the housing 20, and a first planetary gear support frame 21d that rotatably supports the first planetary gear 21 c.

The second planetary gear mechanism 22 is also composed of a second sun gear 22a, second planetary gears 22c, second internal teeth 22b formed on the inner surface of the housing 20, and a second planetary gear support frame 22d that rotatably supports the second planetary gears 22 c.

The first sun gear 21a, the second sun gear 22a, and the inner shaft 3 are concentrically arranged, the first planetary gear support frame 21d and the second sun gear 22a mesh, and the second planetary gear support frame 22d and the inner shaft 3 mesh.

The first sun gear 21a is provided with a square shaft 21a 'projecting outward along the axial center, and the square shaft 21 a' serves as an input shaft 88 connected to the input mechanism 9.

When the input shaft 88 is rotated in the clockwise direction (the tightening direction of the right-handed nut), the inner shaft 3, that is, the nut engaging portion 6 is also rotated in the clockwise direction.

As shown in fig. 1, the inner shaft 3 has a square shaft 31 protruding from the tip thereof, and the engaging portion 6 is detachably attached to the square shaft 31. The engaging portion 6 is a tube seat 61 having an engaging hole 62 to be fitted to a counterpart nut.

As shown in fig. 2 and 3, the outer shaft 4 is a cylindrical body rotatably fitted on the inner shaft 3, and a peripheral wall 43 is provided to protrude from the end of the outer case 20 on the side. A plurality of notches 44 are provided on the outer peripheral portion of the peripheral wall 43 so as to be opened at equal intervals in the circumferential direction, and a plurality of protrusions 23 protruding from the end surface of the outer casing 20 are fitted into the notches 44, whereby the outer shaft 4 and the outer casing 20 are connected together so as to be rotatable integrally.

A concave portion 42 is formed along the outer shaft 4 at the center portion of the outer surface of the outer shaft 4, and a square shaft portion 41 is formed at the tip end portion.

The reaction force receiving member 5 is formed by punching a thick metal plate having a large rigidity into a thick plate having a length of about 25 cm. The reaction force receiving member 5 has a width gradually decreasing from the base end side toward the tip end side, the width of the base end side being about 9cm, the width of the tip end side being about 5cm, and both ends being arc-shaped.

A square hole 51 is provided on the base end side of the reaction force receiver 5, and the square shaft portion 41 of the outer shaft 4 is tightly fitted in the square hole 51. Accordingly, the reaction force receiving member 5 is oriented in a direction orthogonal to the axial centers of the inner shaft 3 and the outer shaft 4.

The tightening torque measurement unit 7 includes: a deformation sensor 71a for detecting deformation of the outer shaft 4 when the nut is tightened, a circuit board 72 for converting the deformation amount of the deformation sensor 71a into a tightening torque amount, a display unit 73 for displaying the tightening torque amount, a battery 74, a housing 75 for housing the above components other than the deformation sensor 71a, and a mounting cylinder 70 fitted to the outer shaft 4 and supporting the housing 75.

The attachment cylinder 70 is fitted to the outer shaft 4 to cover the recessed portion 42 of the outer shaft 4, and is attached to the outer shaft 4 so as to be rotatable integrally with the outer shaft 4 while being sandwiched between the slip-off preventing ring 79 attached to the engaging portion 6 side of the outer shaft 4 and the peripheral wall 43 of the outer shaft 4.

The mounting cylinder 70 has a base 70a protruding in the protruding direction of the reaction force receiver 5, and the housing 75 is rotatably mounted on the base 70 a.

The housing attachment hole 70b is formed in the base 70a in a direction orthogonal to the inner shaft 3 and the outer shaft 4.

The housing 75 protrudes from the pedestal 70a in the same direction as the reaction force receiver 5.

The housing 75 is formed in a rectangular parallelepiped shape, is sized to be covered by the outer contour of the reaction force receiver 5, and is located at a position covered by the reaction force receiver 5 when viewed from the front end side of the engaging portion 6.

A window 75a through which the display unit 73 is visible is formed in the front surface of the case 75, and an energizing switch 78 is provided at one end of the window 75 a.

A cylindrical shaft 76 rotatably fitted into the housing mounting hole 70b is provided in the center of one end of the housing 75 in a protruding manner. A circumferential groove 76a is formed in the shaft 76, and recesses 76c are formed at equal intervals in the circumferential direction of the shaft 76.

The pin 76b provided on the anti-slip ring 79 is fitted into the peripheral groove 76a, and prevents the shaft portion 76 from being pulled out, that is, prevents the housing 75 from falling off from the mounting cylinder 70.

A ratchet (click ball)76d provided to the slip-off preventing ring 79 with an elastic force is fitted into the recess 76c, and the shaft portion 76 is softly locked.

In the embodiment, the housing 75 is formed so that the window 75a thereof is opened at half the circumference of the shaft 76 so as to be rotatable by 180 ° around the position opposite to the reaction force receiver 5.

Further, the shaft 76 is provided with recesses 76c at 5 positions at 45 ° intervals, so that the housing 75 can be rotated 45 ° at a time.

The housing 75 is located as close as possible to the reaction force receiver 5, and is rotatable on the pedestal 70a about the shaft 76.

As shown in fig. 3, the deformation sensor 71a of the embodiment is a deformation gauge 71 stuck on the concave portion 42 of the outer shaft 4. The strain gauge 71 is in an X shape and attached to 4 positions at equal intervals in the circumferential direction of the outer shaft 4.

The strain gauge 71 and the circuit board 72 in the housing 75 are electrically connected by a wire (not shown) passing through the cylindrical shaft 76.

The circuit board 72 is positioned on the window 75a side of the case 75, and the display 73 is provided between the window 75a and the circuit board 72.

The deformation gauges 71 at the 4 positions on the outer shaft 4 form a bridge circuit (not shown) on the circuit board 72, and the tightening torque values corresponding to the average deformation amounts at the 4 positions of the outer shaft 4 to which the deformation gauges 71 are attached are displayed on the display unit 73.

The display unit 73 of the embodiment is configured to display 4 bits by LEDs, and to have numerical values arranged in the longitudinal direction of the housing 75.

The battery 74 is accommodated between the rear surface of the case 75 and the circuit substrate 72. When the switch 78 provided on the front surface of the case 75 is pressed, the circuit board 72 is energized, and when the circuit board 72 does not operate for a predetermined time, the energization of the circuit board 72 is automatically interrupted, thereby preventing the wasteful power consumption of the battery.

The input mechanism 9 is a manual wrench 91, and a square shaft-shaped output shaft 93 is provided on the head 90 of the shank 92 so as to project orthogonally to the shank 92.

The output shaft 93 is able to transmit rotation of the shank in one direction and freewheel in the opposite direction by a ratchet mechanism (not shown) built into the head 90.

As shown in fig. 1, the input receiving portion 8 of the tightening assist unit 1 detachably connected to the input mechanism 9 includes a cover portion 81 for closing an input-side opening of the housing 20 and a one-way clutch 80.

The lid portion 81 is constituted by a lid body 82 and a joint 84 rotatably provided at the center of the lid body 82 via a bearing sleeve 83.

The cover body 82 is attached to the housing 20 by forming convex portions 82a at equal intervals in the circumferential direction on the outer peripheral portion of the cover body 82, fitting the convex portions 82a into the notches 20a formed in the end surface of the housing 20.

The joint 84 has a square hole 84a formed on the side of the square shaft-shaped input shaft 88 of the fastening assisting unit 1 for fitting the input shaft 88, and a square shaft 84b formed on the side opposite to the square hole 84 a.

The one-way clutch 80 is fixed to the lid 81 by a bolt 80c, and is allowed to rotate only in one direction by a ratchet mechanism 80e with respect to a stem member 80d provided on the shaft center. The ratchet mechanism 80e can switch the rotation allowable direction of the stem member 80d by the operation of the switching lever 80 a.

A square hole 80f fitted to the square shaft 84b of the lid 81 and a square hole 80b engaged with the output shaft 93 of the manual wrench 91 are opened in the axial center of the stem member 80 d.

The socket member 80d and the joint 84 constitute a coupling member 87 that is integrally rotatable and detachably coupled to an input shaft 88 of a system for rotationally driving the engagement portion 6 of the fastening assisting unit 1 and an output shaft 93 of a manual wrench.

As shown in fig. 1, an output shaft 93 of a manual wrench 91 is connected to an input shaft 88 of the planetary gear reduction unit 2 via a socket member 80d of the one-way clutch 80 and a joint 84 of the lid portion 81, thereby constituting a fastening device.

The switch 78 of the tightening torque measurement unit 7 is pressed to energize the circuit board 72.

The nut is engaged with the socket 61, and the reaction force receiver 5 is brought into contact with the projection near the nut.

The hand wrench 91 is rotated in the nut tightening direction and then rotated in the opposite direction. This reciprocating motion is repeatedly performed. The output shaft 93 of the hand wrench 91 is rotated only in the nut tightening direction by its own ratchet mechanism and the one-way clutch 80, and the input shaft 88 of the tightening assisting unit 1 is rotated in the same direction. The rotation of the input shaft 88 is decelerated and increased by the planetary gear reduction device 2, and the socket 61 is rotated to tighten the nut.

Since the fastening reaction force at this time is received by the protrusion near the nut through the reaction force receiving member 5, the outer casing 20 and the outer shaft 4 of the planetary gear reduction device 2 do not rotate.

The deformation gauges 71, which are disposed at 4 positions in the circumferential direction of the outer shaft 4 at equal intervals, detect the amount of deformation of the outer shaft 4 caused by the fastening reaction force, and the average value of the deformation is displayed as the fastening torque on the display section 5.

The fastening torque measurement unit 7 is configured such that the circuit board 72, the display portion 73, and the battery 74, which are bulky among the components of the unit, are housed in the case 75, and the case 75 is provided so as to project from the outer shaft 4 in the same direction as the reaction force receiving member 5, so that the length of the case 75 projecting partially to the outside is increased, but there is no need for a rigid, large-sized cylindrical case that serves as a case for protecting the components, as in the fastening torque measurement unit of the above-mentioned patent publication, and therefore the fastening torque measurement unit 7 is small and lightweight as a whole.

Since the housing 75 projects to the side of the outer shaft 4, it is considered that the impact when the projection for contacting the reaction force receiver 5, other work, or the like contacts the housing 75 is weak. However, since the case 75 has a size covered by the reaction force receiving member 5 having a high rigidity for receiving the fastening reaction force and is located at a position covered by the reaction force receiving member, it is possible to prevent the work or the like from directly hitting the case, and to avoid the fastening torque measurement unit 7 from being damaged.

Further, when the fastening assisting unit 1 is set on the floor, the reaction force receiver 5 is in contact with the floor, and the case 75 is in a state of being lifted from the floor, so that the load of the fastening assisting unit 1 is not applied to the case 75, and the case 75 can be protected by the reaction force receiver 5 in this point.

In the 4 deformation gauges 71, a slight deviation occurs in the amount of deformation by the fastening reaction force from the protrusion near the nut by the reaction force receiver 5. As described above, the deformation amount is measured by the deformation gauges 47 provided at 4 positions, and the measured average value of the deformation is displayed, thereby improving the reliability of the measurement.

Since the display portion 73 displays a numerical value in the direction of projection of the housing 75 from the outer shaft 4 in the direction orthogonal to the axial center of the outer shaft 4, the operator who rotates the manual wrench 91 can easily see the display portion 73.

Further, the housing 75 is rotatable about the shaft portion 76 in a plane orthogonal to the axial center of the outer shaft 4, and therefore can be switched to an angle that can be easily viewed by an operator.

The shortage of the input torque inputted by the manual wrench 91 can be compensated by the deceleration and reinforcement action of the planetary gear reduction gear 2 built in the fastening assisting unit 1.

Since the one-way clutch 80 is provided in the input receiving portion 8, a torsional force acts on the tightening assist unit 1 during tightening, and even if the entire tightening assist unit 1 is elastically deformed in the torsional direction, the shank 92 does not rotate in the anti-tightening direction in accordance with the elastic restoration amount.

If it is found that the handle is slightly rotated reversely due to the torsional elastic restoration of the tightening assist unit 1, the one-way clutch 80 may be omitted by changing the design of the joint 84 of the cap 81 so as to connect the input shaft 88 of the tightening assist unit 1 and the output shaft 93 of the manual wrench 91.

< second embodiment (fig. 6, fig. 7) >

Compared with the first embodiment described above, the input mechanism 9 and the input receiving portion 8 of the fastening assisting unit 1 are different. Since the other structures are common to the first embodiment, the description is omitted.

The input mechanism 9 is a power fastening machine 94 having 1 output shaft, and although the output torque is not large, it can be used in various operations by attaching an output shaft 96 of a drill, a socket, or the like to a rotary drive shaft 95, and is inexpensive and highly versatile.

In the embodiment, the output shaft 96 of the 1-output-shaft power fastening machine 94 includes a square shaft 96a at the front end.

The input receiving portion 8 of the fastening assisting unit 1 is a lid portion 81 fitted into the input side opening of the housing 20, and the lid portion 81 is provided with a joint 84 rotatably on the axis of the lid main body 82 via a bearing sleeve 83.

The joint 84 has a square hole 84a on the input shaft 88 side of the tightening assistance unit 1 to engage with the input shaft 88, and a square hole 84a on the other end side to engage with a square shaft 96a on the power tightening machine 94 of 1 output shaft.

The joint 84 is a second coupling member 87 that integrally rotates and detachably couples an input shaft 88 of a system for rotationally driving the engagement portion 6 of the fastening assisting unit 1 and an output shaft 96 of the power fastening machine.

The effect of the fastening assisting unit 1 in embodiment 2 is the same as that in embodiment 1.

In embodiment 2, power can be input into the fastening assisting unit 1 by the power fastening machine 94 of 1 output shaft.

Although the torque is not large, the power tightening machine 94 with 1 output shaft is generally used because it is inexpensive, lightweight, and easy to use.

The shortage of the input torque inputted by the power fastening machine 94 of 1 output shaft can be compensated by the deceleration and reinforcement action of the planetary gear reduction unit 2 built in the fastening assisting unit 1.

< third embodiment (fig. 8, fig. 9) >

Compared with the first embodiment described above, the input mechanism 9 and the input receiving portion 8 of the fastening assisting unit 1 are different.

Since the other structures are common to the first embodiment, the description is omitted.

The input mechanism 9 is a well-known dual-output-shaft power fastening machine 97 also called a nut runner, and is driven by an electric motor 97 b. The input mechanism 9 includes a power mechanism 97a that is decelerated by a planetary gear, and an inner output shaft 98 and an outer output shaft 99 are concentrically protruded.

The input receiving portion 8 of the tightening assist unit 1 is a lid portion 81 fitted into the input-side opening of the housing 20, and the lid portion 81 is provided with a joint 84 on the input shaft 88 side on the axis of the cylindrical lid body 82, and a square hole 82b engaging with the outer output shaft 99 of the dual-output-shaft power tightening machine 97 on the opposite side.

The joint 84 is rotatably attached to the cover body 82 via a bearing sleeve 83, and has a square hole 84a on the input shaft 88 side to engage with the input shaft 88 and a square hole 84c on the other end side to engage with an inner output shaft 98 of a dual-output shaft power fastening machine 97.

The lid portion 81 has a projection 82a that engages with the notch 20a of the housing 20, and the lid body 82 and the housing 20 form a first connection member 86 that connects the outer output shaft 99 of the power fastening machine 97 of the dual output shafts and the outer shaft 4 of the fastening assisting unit 1 so as to be integrally rotatable and detachably.

The cover body 82 is provided with a fastening bolt 85 for fixing the outer output shaft 99 of the dual output shaft power fastening machine 97 fitted in the square hole 82 b.

The joint 84 is a second coupling member 87 that integrally rotatably and detachably couples the inner output shaft 98 of the dual-output-shaft power fastening machine 97 and the input shaft 88 of the system for rotationally driving the engagement portion 6 of the fastening assisting unit 1.

The effect of the fastening assisting unit 1 in embodiment 3 is the same as that in embodiment 1.

In embodiment 3, power can be input into the fastening assisting unit 1 by the power fastening machine 97 equipped with a dual output shaft.

Since the power fastener 97 of the dual output shafts can be fastened with a larger torque than the power fastener 94 of the 1 output shaft of embodiment 2, it is possible to fasten with a larger torque in addition to the deceleration boosting action of the planetary gear reduction gear transmission 2 incorporated in the fastening assisting unit 1.

Effects of the invention

In the tightening torque measuring unit 7 in the bolt or nut tightening machine according to the present invention, the circuit board 72, the display portion 73, and the battery 74, which are bulky in the structural components of the unit, are housed in the case 75, and the case 75 is provided so as to project from the outer shaft 4 in the same direction as the reaction force receiving member 5, so that although the length of the case 75 projecting partially to the outside is increased, a large-sized cylindrical case having high rigidity, which serves as a case for protecting the structural components, is not required as in the tightening torque measuring unit of the above-mentioned patent publication, and therefore the entire tightening torque measuring unit 7 is small and light.

Since the housing 75 projects to the side of the outer shaft 4, it is considered that the impact when the work or the like comes into contact with the housing 75 is weak. However, since the reaction force receiving member 5 having a high rigidity is positioned closer to the nut engaging portion 6 than the case 75 and the case 75 has a size of being accommodated in the contour of the reaction force receiving member 5, it is possible to prevent a projection or the like contacting the reaction force receiving member 5 from directly hitting the case and to avoid breakage of the tightening torque measurement unit 7.

Further, when the fastening assisting unit 1 is placed on a floor surface by being tilted, the reaction force receiving member 5 is in contact with the floor surface, and the case 75 is in a state of being lifted from the floor surface, so that the load of the fastening assisting unit 1 is not applied to the case 75, and the case 75 can be protected by the reaction force receiving member 5.

As described above, since the fastening assisting unit 1 can be made small and light, the bolt or nut fastening machine including the input mechanism 9 can be made small and light as a whole, and thus has excellent maneuverability and is easy to use.

Since the display section 73 displays the tightening torque value in parallel in the protruding direction of the housing 75, the operator can easily see the value while operating the input mechanism (9).

Since the housing 75 can rotate about an axis perpendicular to the axis of the outer shaft 4, the housing can be tilted by rotation, and the numerical value of the display portion 73 can be more easily seen.

When the input mechanism 9 is the dual output shaft power fastening machine 97, since the planetary gear mechanism is built in the structure and fastening can be performed with a large torque, fastening can be performed with a large torque in addition to the deceleration boosting action of the planetary gear reduction unit 2 built in the fastening assisting unit 1.

In the case of the power fastening machine 94 in which the input mechanism 9 is a 1-output shaft, although the torque is not large, the fastening machine is generally used because it is inexpensive and lightweight, and is easy to use. The shortage of the torque input by the power fastening machine 94 of 1 output shaft can be compensated by the deceleration and reinforcement action of the planetary gear reduction unit 2 incorporated in the fastening assisting unit 1.

When the input mechanism 9 is the manual wrench 91, although a large output force cannot be provided, it can be supplemented by the deceleration and reinforcement action of the planetary gear reduction unit 2 incorporated in the fastening assisting unit 1. At the time of tightening, a torsional force acts on the tightening assist unit 1, the entire tightening assist unit 1 is elastically deformed in the torsional direction, the shank is rotated in the tightening direction, and then at the moment the shank is returned to the opposite side, the torsional elasticity of the tightening assist unit 1 is restored, and the shank is rotated in the counter-tightening direction in accordance with the amount of elastic restoration. Therefore, even when the handle is rotated back and forth, there is a problem that the torsional elastic deformation amount of the tightening assisting unit 1 does not act at the time of tightening. However, as described above, if the one-way clutch 80 is provided, the rotation angle of the shank can be made to correspond to the actual tightening angle by preventing the reverse rotation of the shank caused by the torsional elastic recovery of the tightening assist unit 1.

The above embodiments are described for illustrating the present invention, but the invention described in the claims is not limited to the embodiments or the scope of the claims is not limited to the embodiments or the claims. It is to be understood that the configurations of the respective portions of the present invention are not limited to the above-described embodiments, and various modifications can be made within the technical scope described in the claims.

For example, the deformation sensor 71a for detecting the amount of deformation of the outer shaft 4 when the nut is fastened may be any deformation sensor that can be provided on the outer shaft 4 without excessively increasing the fastening torque measurement unit 7, such as a magnetostrictive deformation sensor, regardless of the type of sensor.

Claims (8)

1. A bolt or nut fastening device comprising a fastening assistance unit (1) and an input mechanism (9) in combination, wherein the fastening assistance unit (1) has an outer shaft (4) and an inner shaft (3) which are connected to a planetary gear reduction device (2), concentrically arranged in front of an outer case (20), and rotatable in opposite directions to each other, a reaction force receiving member (5) is provided so as to protrude laterally from the outer shaft (4), an engagement portion (6) with which an opposing bolt or nut is engaged is provided in the inner shaft (3), and the input mechanism (9) is connected to the planetary gear reduction device (2), the bolt or nut fastening device being characterized in that:

a fastening torque measurement unit (7) is provided on an outer shaft (4), a peripheral wall (43) is provided on the outer shaft (4) so as to protrude from the end of the outer shaft (20), a slip-off prevention ring (79) is attached to the end of the outer shaft on the side of an engagement portion (6), and the fastening torque measurement unit (7) includes: a deformation sensor (71a) attached to a recessed portion (42) formed on the outer periphery of the outer shaft (4); an installation cylinder (70) which is clamped by the peripheral wall (43) of the outer shaft (4) and the anti-falling ring (79) and can be installed with the outer shaft (4) in an integrated rotating way; a circuit board (72) for converting the deformation amount of the outer shaft (4) detected by the deformation sensor (71a) into a fastening torque amount; a display unit (73) for displaying the fastening torque; a battery (74); and a housing (75) that houses the circuit board (72), the display unit (73), and the battery (74), wherein the housing (75) protrudes in the same direction as the reaction force receiving member (5) from the outer peripheral portion of the mounting cylinder (70), and is formed to have a size that is covered by the outer contour of the reaction force receiving member (5) and is located at a position that is covered by the reaction force receiving member (5) when viewed from the front end side of the engagement unit (6), the mounting cylinder (70) covers the deformation sensor (71a) by covering the recessed portion (42) of the outer shaft (4), and the reaction force receiving member (5) has a function of protecting the housing (75) from an external impact.

2. The bolt or nut fastening device according to claim 1, characterized in that:

the display section (73) is configured in such a manner that numerical values are arranged in the protruding direction of the housing (75).

3. The bolt or nut fastening device according to claim 1, characterized in that:

the housing (75) can rotate around a shaft (76) orthogonal to the axial center of the outer shaft (4).

4. The bolt or nut fastening device according to claim 2, characterized in that:

the housing (75) can rotate around a shaft (76) orthogonal to the axial center of the outer shaft (4).

5. A bolt or nut fastening device according to any one of claims 1 to 4, wherein:

the input mechanism (9) is a power fastening machine (97) having two output shafts, namely an inner output shaft (98) and an outer output shaft (99), which are concentric, an input receiving portion (8) provided in the fastening assistance unit (1) has a first connecting member (86) and a second connecting member (87), the first connecting member (86) is capable of rotating integrally and detachably connecting the outer shaft (4) of the fastening assistance unit (1) and the outer output shaft (99) of the power fastening machine (97), and the second connecting member (87) is capable of rotating integrally and detachably connecting the input shaft (88) of a system for rotationally driving the engaging portion (6) of the fastening assistance unit (1) and the inner output shaft (98) of the power fastening machine (97).

6. A bolt or nut fastening device according to any one of claims 1 to 4, wherein:

the input mechanism (9) is a power fastening machine (94) having 1 output shaft, and the input receiving part (8) provided on the fastening auxiliary unit (1) has a connecting member (87), and the connecting member (87) is capable of integrally rotating and detachably connecting the input shaft (88) of a system for rotationally driving the engaging part (6) of the fastening auxiliary unit (1) and the output shaft (96) of the power fastening machine.

7. A bolt or nut fastening device according to any one of claims 1 to 4, wherein:

the input mechanism (9) is a manual wrench (91), and an input receiving part (8) provided on the fastening assisting unit (1) has a connecting member (87), and the connecting member (87) is capable of integrally rotating and detachably connecting an input shaft (88) of a system for rotationally driving the engaging part (6) of the fastening assisting unit (1) and an output shaft (93) of the manual wrench.

8. A bolt or nut fastening device according to any one of claims 1 to 4, wherein:

the input mechanism (9) is a manual wrench (91), an input receiving part (8) arranged on the fastening auxiliary unit (1) is provided with a connecting component (87) and a one-way clutch (80), the connecting component (87) can integrally rotate and can detachably connect an input shaft (88) of a system for rotationally driving an engagement part (6) of the fastening auxiliary unit (1) and an output shaft (93) of the manual wrench, and the one-way clutch (80) is arranged on the fastening auxiliary unit (1) and allows the manual wrench to rotate in a desired direction and prevents the manual wrench from rotating in the opposite direction.