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EP-4147822-B1 - FASTENING TOOL

EP4147822B1EP 4147822 B1EP4147822 B1EP 4147822B1EP-4147822-B1

Inventors

  • OSAWA, Yusuke
  • TAKEUCHI, KAZUYA

Dates

Publication Date
20260513
Application Date
20220912

Claims (9)

  1. A fastening tool comprising: a bit holding portion (3) which detachably holds a driver bit (2) and is configured to rotate in a circumferential direction of the driver bit (2) and move in an axial direction of the driver bit (2); a first motor (40) configured to rotate the bit holding portion (3); a second motor (50) configured to move the bit holding portion (3) along the axial direction; and a control unit (100) configured to control a position of the bit holding portion (3) along the axial direction by the number of rotations of the second motor (50), wherein the control unit (100) is configured to control a moving speed of a screw moved by rotation of the first motor (40) or a rotation speed of the first motor (40), wherein the control unit (100) is configured to control a moving speed of the bit holding portion (3) moved by rotation of the second motor (50) to follow a moving speed of a screw moved by being fastened to a fastening target by rotation of the first motor (40), characterized in that the control unit (100) is configured to calculate a moving speed of the bit holding portion (3) based on a lead length of the screw.
  2. The fastening tool according to claim 1, wherein the control unit (100) is configured to control a rotation speed of the second motor (50) based on a rotation speed of the first motor (40), or to control the rotation speed of the first motor (40) based on the rotation speed of the second motor (50).
  3. The fastening tool according to claim 1 or 2, wherein the control unit (100) is configured to control the moving speed of the bit holding portion (3) moved by rotation of the second motor (50) to follow the moving speed of the screw moved by rotation of the first motor (40), when a load applied to the first motor (40) or the second motor (50) is detected.
  4. The fastening tool according to claim 1, wherein the control unit (100) is configured to calculate the lead length of the screw using the number of rotations of the first motor (40) or a movement amount of the bit holding portion (3) measured after a load applied to the first motor (40) or the second motor (50) is detected, and to calculate the moving speed of the bit holding portion (3) based on the calculated lead length.
  5. The fastening tool according to claim 1, further comprising: a lead length setting portion (120) configured to set the lead length, wherein the control unit (100) is configured to calculate the moving speed of the bit holding portion (3) based on the lead length of the screw set by the lead length setting portion (120).
  6. The fastening tool according to claim 1, wherein the control unit (100) is configured to control a moving speed of the bit holding portion (3) moved by rotation of the second motor (50) based on the rotation speed of the first motor (40).
  7. The fastening tool according to claim 6, wherein the control unit (100) is configured to control the moving speed of the bit holding portion (3) moved by rotation of the second motor (50) based on a load applied to the first motor (40) or the second motor (50).
  8. The fastening tool according to claim 6 or 7, wherein the control unit (100) is configured to control the moving speed of the bit holding portion (3) moved by rotation of the second motor (50) based on a fluctuation in a power supply voltage.
  9. The fastening tool according to claim 7, wherein the control unit (100) is configured to control such that the load on the second motor (50) falls within a range of specified values, after the load is detected.

Description

TECHNICAL FIELD The present disclosure relates to a fastening tool in which a driver bit is engaged with a screw, the screw is pressed against a fastening target by the driver bit, and the driver bit is rotated to screw. BACKGROUND ART There is a tool called a portable striking machine which uses an air pressure of compressed air supplied from an air compressor or a combustion pressure of gas to sequentially strike connection stoppers loaded in a magazine from a tip end of a driver guide. As a tool which rotates a bit to tighten a screw and moves the bit in a direction of tightening the screw, a pneumatic screw driving machine is proposed in the related art, in which the bit is rotated by an air motor and moved in a direction of tightening the screw by an air pressure (for example, see Publication of Japanese Patent No. 5262461). A screwdriver is proposed in which a spring is compressed by a driving force of a motor which rotates a screw, and the screw is driven by biasing of the spring (for example, see Publication of Japanese Patent No. 6197547). In a tool having a configuration in which a bit is moved in a direction of tightening a screw, the faster a forward speed of the bit than a forward speed of the screw determined by a rotation speed of the screw, the greater a so-called reaction that separates a tool body from a fastening target. When the reaction becomes large, the tool body may float up from the fastening target, resisting a force with which an operator presses the tool body against the fastening target. However, if the tool body floats up from the fastening target by the reaction, an operation may be completed in a state where the screw cannot be completely tightened. Therefore, in order to improve quality of screw tightening, it is necessary to prevent the reaction, that is, to operate the bit (move the bit forward) at an appropriate speed in accordance with the rotation speed of the screw. However, in a fastening tool in the related art, there is no idea of controlling the forward speed of the bit in accordance with the rotation speed. In both of the screw driving machine which uses the air pressure and the screwdriver which drives the screw by biasing of the spring, it is difficult to control a moving speed of a driver bit by an operation of moving the driver bit in a direction of tightening the screw. The present disclosure is made to solve such a problem, and an object of the present disclosure is to provide a fastening tool capable of controlling a moving speed of a driver bit by an operation of moving the driver bit in a direction of tightening a screw. EP 4 052 848 A1 relates to a fastening tool configured to engage a driver bit with a screw, to push and press the screw against a fastening target with the driver bit, and to rotate the driver bit for screwing. In particular, it describes a bit rotating motor (first motor) which is to rotate the driver bit, and a bit moving motor (second motor). By controlling an amount of rotation of the bit moving motor an amount of movement of the driver bit is controlled. WO 2020/009159 A1 which discloses the preamble of claim 1 relates to a screw fastening error determination device having a rotation servo that makes a driver rotate and a reciprocation servo that makes the driver move back and forth. SUMMARY An aspect of the present disclosure relates to a fastening tool according to claim 1. BRIEF DESCRIPTION OF DRAWINGS FIG. 1A is a side cross-sectional view showing an example of an internal structure of a fastening tool according to the present embodiment.FIG. 1B is a top cross-sectional view showing an example of the internal structure of the fastening tool according to the present embodiment.FIG. 1C is a front cross-sectional view showing an example of the internal structure of the fastening tool according to the present embodiment.FIG. 2A is an exploded perspective view showing an example of the internal structure of the fastening tool according to the present embodiment.FIG. 2B is an external perspective view showing an example of the fastening tool according to the present embodiment.FIG. 3A is a perspective view showing an example of configurations of main parts of the fastening tool according to the present embodiment.FIG. 3B is a perspective view showing an example of configurations of main parts of the fastening tool according to the present embodiment.FIG. 4A is a cross-sectional perspective view showing an example of configurations of main parts of the fastening tool according to the present embodiment.FIG. 4B is a cross-sectional perspective view showing an example of configurations of main parts of the fastening tool according to the present embodiment.FIG. 4C is a cross-sectional perspective view showing an example of configurations of main parts of the fastening tool according to the present embodiment.FIG. 5 is a top cross-sectional view showing an example of configurations of main parts of the fastening tool according to the prese