Abstract: Provided is a nut and a bolt tightening method for fastening an object, wherein a tightening force is applied on the object by rotating a nut or a bolt in a state in which a predetermined tension force is applied on the bolt in the axial direction of the bolt. When the tensile force exerted on the bolt decreases as the tightening force increases and after a timing when an inflection point occurs in a time course change in a ratio of an amount of change in the tensile force exerted on the bolt to an amount of change in an angle of rotation of the nut or the bolt, the tightening resulting from the rotation of the nut or bolt is terminated and the tensile force applied on the bolt is removed.

Abstract: Tightening device can fasten a fastening element by a target tightening force with good accuracy and facilitate automation. The tightening device includes a cylindrical drive socket holding a nut in the lower end opening thereof; a nut holder disposed inside the drive socket, a bolt passing through a bottom thereof, and regulating movement of the nut held by the drive socket toward the tip end of a threaded par; a tension rod which is disposed inside the nut holder and the lower end face of which has a threaded hole into which a portion of the threaded part that is further on the tip end side than the nut is screwed; a sensor for detecting tension force; a first motor for turning the tension rod around an axis that extends in the vertical direction; and a second motor for turning the drive socket around an axis.

Abstract: A fastening device for fastening a bolt to a fastening target object, wherein the bolt has a bolt head female screw section in an inner circumferential surface of a recess provided in an upper surface of a bolt head section. The fastening device includes a tension rod having a rod male screw section engaging the bolt head female screw section; a drive socket circumferentially surrounding the tension rod and having a lower end section with a grasper for laterally grasping the bolt head section; a supporter circumferentially surrounding the drive socket and having a lower end section protruding downward beyond a lower end section of the drive socket; a sensor for sensing compression force acting on the supporter in the upward/downward direction; a first motor for rotating the tension rod around an axis extending in the upward/downward direction; and a second motor for rotating the drive socket around the axis.

Abstract: In a fastening device for fastening a bolt, a male thread is formed on a side surface of a bolt head part, and a part to be engaged is formed on a top surface of the bolt head part. The fastening device includes a bit having a tension rod having a rod female thread part, and an engaging part installed inside the tension rod and engaging the engaged part, the bit causing the bolt to rotate where the engaged part and engaging part are engaged; a supporter surrounding the tension rod in the circumferential direction such that the lower end part thereof protrudes below the lower end part; a sensor for sensing vertical compression force acting on the supporter; a first motor for causing the bit to rotate about the axis; and a second motor for causing the tension rod to rotate about the vertically extending axis.

Abstract: A tensioning device is configured to apply upward tension to a bolt-nut fastener including a bolt fitted with a fastened member H, and a nut to be fastened to a shaft of the bolt, which protrudes from the fastened member. A first male thread portion is formed on an outer circumferential surface of the nut. The tensioning device includes a connection member having a first female thread portion to be engaged with the first male thread portion, a tensioning mechanism for tensioning the nut via the connection member in a state where the first male thread portion is engaged with the first female thread portion, and a tension bearer which is disposed around an outer circumference of the connection member, and bears a reaction force applied from the fastened member H in tensioning performed by the tensioning mechanism.

Abstract: To provide a tensioning device capable of tensioning a bolt from a bolt head side while suppressing increase in the number of components. A tensioning device is configured to apply upward tension to a bolt fastened to a fastened member H. A first male thread portion is formed on an outer circumferential surface of a head of the bolt. The tensioning device includes a connection member having a first female thread portion to be threadly engaged with the first male thread portion, a tensioning mechanism for tensioning the bolt via the connection member in a state where the first male thread portion is threadly engaged with the first female thread portion, and a tension bearer which is disposed around an outer circumference of the connection member, and bears a reaction force applied from the fastened member H in tensioning performed by the tensioning mechanism.

Abstract: An error of an axial force detection is reduced by tensioning a bolt with a tensioning device engaged with a part of the bolt, different from a shaft portion of the bolt. A tensioning device is configured to apply upward tension to a bolt fastened to a fastened member H, and fitted with a washer. A first male thread portion is formed on an outer circumferential surface of the washer. The tensioning device includes a connection member having a first female thread portion to be engaged with the first male thread portion, a tensioning mechanism for tensioning the connection member in a state where the first male thread portion is engaged with the first female thread portion, and a tension bearer which is disposed around an outer circumference of the connection member, and bears a reaction force applied from the fastened member H in tensioning performed by the tensioning mechanism.

Abstract: A tightening tool such as a torque wrench is provided in which electric power can be fed to an electronic circuit with eliminating the need for a battery and achieving daily maintenance-free. In the tightening tool, when a tightening torque has reached a set torque value and a torque limiter is actuated, an electronic circuit unit that has obtained a detection signal outputted from a torque limiter actuation detection unit outputs a tightening completion signal. The tightening tool has a power generation unit for feeding electric power to the electronic circuit unit at least during the actuation of the torque limiter. The power generation unit performs photovoltaic power generation, electromagnetic induction power generation, power generation by conversion from mechanical energy into electrical energy, or temperature difference power generation.

Abstract: An angle wrench has a simple structure and is capable of accurately measuring rotation angle. The angle wrench is used for tightening an object to be tightened by means of the rotation angle method, and includes a handle having a grip; a head section having a tightening head for tightening the object to be tightened, and a tail section that extends from the tightening head pivotally supported with respect to the handle via a head pin; torque-detecting mechanisms for detecting when the torque for tightening the object being tightened reaches the specified torque; and a rotation angle-measuring section for measuring the rotation angle of the angle wrench in a tightening action, on the basis of the angular velocity of the angle wrench around the axis of the object being tightened, after the torque-detecting mechanism has detected that the specified torque has been reached.

Abstract: A tightening tool such as a torque wrench is provided in which electric power can be fed to an electronic circuit with eliminating the need for a battery and achieving daily maintenance-free. In the tightening tool, when a tightening torque has reached a set torque value and a torque limiter is actuated, an electronic circuit unit that has obtained a detection signal outputted from a torque limiter actuation detection unit outputs a tightening completion signal. The tightening tool has a power generation unit for feeding electric power to the electronic circuit unit at least during the actuation of the torque limiter. The power generation unit performs photovoltaic power generation, electromagnetic induction power generation, power generation by conversion from mechanical energy into electrical energy, or temperature difference power generation.

Abstract: It is to provide a torque driver capable of bringing a marker into direct contact with a surface of a fastener member such as a screw to perform marking. A torque driver 1 is configured such that a case 10 is rotated relative to a main shaft 20 when a tightening force applied to the case 10 is transmitted to the main shaft 20 through a torque limiter section 30 and a tightening torque on a screw 80 engaged with a bit 70 attached to a coupler 60 fixed at a tip portion of the main shaft 20 reaches a torque value set in the torque limiter section 30. The torque driver 1 includes: a marker 54 extending from an inside of the coupler 60 to a tip portion of the bit 70 along a side surface of the bit 70; and a marker activating section 40 that allows the marker 54 to move forward by utilizing rotation of the case 10 relative to the main shaft 20 so that a marker tip portion 53 is brought into contact with the screw 80 to perform marking.

Abstract: A torque wrench equipped with a cam-type torque detection mechanism is provided which is capable of detecting a torque with high accuracy, providing a non-unusual-feeling of handle operation after torque has been detected, and enabling tightening of fastened members such as bolts with safety.

Abstract: The torque tool device includes a torque tool and an information processing terminal. The torque tool is capable of measuring the torque value at which a bolt or the like was tightened and then transmitting the measured torque value via wireless communication unit and the information processing terminal has information processing unit receiving the measured torque value and determining whether the torque value is acceptable.

Abstract: To make improvements in torque wrenches with a torque limiter that uses a cam mechanism and to provide a torque wrench that realizes more stable operation and is capable of highly precise tightening. In a torque wrench with a torque limiter that uses a cam mechanism, a solid columnar roller member 14 is engaged with a cam part 7 of a cam shaft 8 such that it is rotatably supported by a roller support lever member 12 mounted in a head portion 2 such as to be rotatable around a support shaft 16 and such that it is pressed against the cam part 7 by a spring force transmitting rod 18 biased by a torque setting spring. The roller support lever member 12 is configured such that the distance r2 from the support shaft 16 to a point of application of force of the spring force transmitting rod 18 is longer than the distance r1 from the support shaft 16 to the roller member 14.

Abstract: A torque wrench equipped with a cam-type torque detection mechanism is provided which is capable of detecting a torque with high accuracy, providing a non-unusual-feeling of handle operation after torque has been detected, and enabling tightening of fastened members such as bolts with safety.

Abstract: To make improvements in torque wrenches with a torque limiter that uses a cam mechanism and to provide a torque wrench that realizes more stable operation and is capable of highly precise tightening. In a torque wrench with a torque limiter that uses a cam mechanism, a solid columnar roller member 14 is engaged with a cam part 7 of a cam shaft 8 such that it is rotatably supported by a roller support lever member 12 mounted in a head portion 2 such as to be rotatable around a support shaft 16 and such that it is pressed against the cam part 7 by a spring force transmitting rod 18 biased by a torque setting spring. The roller support lever member 12 is configured such that the distance r2 from the support shaft 16 to a point of application of force of the spring force transmitting rod 18 is longer than the distance r1 from the support shaft 16 to the roller member 14.

Abstract: An object is to provide a torque tool device which can expedite tightening operations using a torque tool without requiring any other manipulation than the tightening. The device is also capable of performing tightening operations consecutively by determining instantly whether the tightening has been adequately performed. The torque tool device includes a torque tool 1 and an information processing terminal 20. The tool 1 is capable of measuring the torque value at which a bolt or the like was tightened and then transmitting the measured torque value via wireless communication means. The terminal 20 has information processing means for receiving the measured torque value and determining whether the torque value is acceptable. This arrangement eliminates the need of including a pass/fail test device in the torque tool 1, thereby allowing it to be reduced in weight.

Abstract: An object is to provide a torque tool device which can positively identify which torque tool was used to tighten a bolt. Another object is to provide a torque tool device which can be provided with traceability from the torque tool to standards of torque. A torque wrench 1 transmits, after having tightened a bolt, a set of the manufacturer's serial number of the torque wrench 1 and tightening data such as a measured torque value to a processing terminal 20. The processing terminal 20 transmits the manufacturer's serial number and the tightening data to an externally connected device 30, so that the tightening data and data on the tightened bolt or the like are recorded by the manufacturer's serial number in the externally connected device. This makes it possible to identify the torque wrench 1 from the tightened bolt and maintain traceability.

Abstract: A torque wrench for additional tightening inspection can measure a precise torque value by simply tightening the tightening bolt additionally. When the inspection bolt is tightened, the rotation of the wrench is detected before the rotation of the bolt due to the torsion of the wrench itself. The intersection P between a torque gradient line M obtained at that time and a torque gradient line N of a rotating state after the rotation of the bolt makes a measuring point. The torque value at this intersection P is determined to obtain a torque measurement. Here, the torque gradient line N is obtained by connecting several points each corresponding to a torque value of 90% of the torque value TA at the intersection PA with a referential torsional torque gradient line L.