Torque wrench

• US 7,832,286 B2
• Filed: 01/09/2006
• Issued: 11/16/2010
• Est. Priority Date: 04/07/2005
• Status: Active Grant

• Current Assignee: Hosiden Corporation, Kyoto Tool Co., Ltd.
• Original Assignee: Hosiden Corporation, Kyoto Tool Co., Ltd.
• Inventors: Fujita, Kouji, Nakagawa, Takamichi, Hanai, Tadashi, Nakata, Shogo, Umekawa, Masahiko
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): Davis; Octavia
• Application Number:
  US11/327,495
• Publication Number:
  US 20060225519A1
• Time in Patent Office: 1,772 Days
• Field of Search: 738/622.2, 738/622.1, 738/622.3, 738/622.6
• US Class Current: 73/862.22
• CPC Class Codes: B25B 23/1425 by electrical means

Abstract

The invention seek to enable to share main components other than a tightening unit even in use for different effective lengths corresponding to ranges of tightening torques. There are provided: a tightening unit 10 such as a ratchet; a housing 20 having a two-divided structure including a front side cover part 21 and a back side grip part 22; a strain body 30 provided inside the housing 20 and replaceably coupling the tightening unit 10 thereto; a distortion sensor 40, provided to the strain body 30, for detecting the distorted amount of the strain body 30 due to the tightening force of the tightening unit 10; a microprocessor chip 100 having functions including computing the tightening torque of the tightening unit 10 based on torque reference values prepared in advance and detection results of the distortion sensor 40; and an output unit 300 for outputting such as the tightening torque.

Claims

1. A torque wrench, comprising:

a tightening unit;

a housing;

an axis;

a strain body including a tip part for replaceably connecting the tightening unit thereto;

a setting unit for selectively inputting a type of the tightening unit thereto;

a distortion sensor for detecting a distorted amount of the strain body corresponding to a tightening force of the tightening unit;

a torque computation unit, in which a plurality of predetermined torque reference values required for computing tightening torques of different types of tightening units and corresponding to effective lengths of the tightening units have been prepared in advance, for computing the tightening torque T=(R×

D) based on an appropriate one value R of the torque reference values that corresponds to the type of the tightening unit and a detection result D of the distortion sensor;

an output unit for outputting at least a computation result by the torque computation unit as a tightening torque measurement value; and

a memory unit, externally connected to a device incorporating the torque computation unit, for storing therein the predetermined torque reference values for outputting to the computation unit,

wherein said torque reference value R is determined by R=T0/D0, in which T0 is a tightening torque at a preset reference weight, and D0 is an output value of said distortion sensor at said preset reference weight;

wherein the housing includes;

a front side cover part in a cylindrical shape for accommodating the tip part of the strain body, a tip face thereof having a hole for inserting a base end part of the tightening unit; and

a back side grip part in a cylindrical shape for accommodating a base end part of the strain body,

wherein the axis is disposed inside the back side grip part and extends in a direction orthogonal to the tightening force of the tightening unit so as to pass through the strain body, and

wherein the back side grip part is capable of tilting slightly with respect to the front side cover part with the axis rotatably supporting the back side grip part.

2. The torque wrench as claimed in claim 1, comprising:

a setting unit for setting a tightening torque set value; and

a torque judgment unit for judging whether or not the torque measurement value shown by the computation result of the torque computation unit is close to/has reached the tightening torque set value as set through the setting unit, and causing the output unit to output the judgment result.

3. The torque wrench as claimed in claim 2, wherein the housing is provided with a lock mechanism for releasably locking the back side grip part to prevent tilting of the grip part with respect to the front side cover part.

4. The torque wrench as claimed in claim 3, wherein the lock mechanism is configured to include a lock member rotatably coupled to a back end part of the back side grip part, the lock member having a movement regulating long hole for inserting the back end part of the strain body thereinto.

5. A torque wrench, comprising:

a tightening unit;

a strain body including a tip part for replaceably connecting the tightening unit thereto;

a housing of a two-divided structure including;

a front side cover part in a cylindrical shape for accommodating the tip part of the strain body, a tip face thereof having a hole for inserting a base end part of the tightening unit; and

a back side grip part in a cylindrical shape for accommodating a base end part of the strain body and having an axis, inside thereof, extending in a direction orthogonal to the tightening force of the tightening unit, the strain body being rotatably supported by the axis such that the back side grip part is capable of tilting slightly with respect to the front side cover part;

a setting unit for selectively inputting a type of the tightening unit thereto;

a distortion sensor for detecting a distorted amount of the strain body corresponding to a tightening force of the tightening unit;

a torque computation unit, in which a plurality of predetermined torque reference values required for computing tightening torques of different types of tightening units and corresponding to effective lengths of the tightening units have been prepared in advance, for computing the tightening torque T=(R×

D) based on an appropriate one value R of the torque reference values that corresponds to the type of the tightening unit and a detection result D of the distortion sensor, wherein said torque reference value R is determined by R=T0/D0, in which T0 is a tightening torque at a present reference weight, and D0 is an output value of said distortion sensor at said present reference weight;

an output unit for outputting at least a computation result by the torque computation unit as a tightening torque measurement value;

a memory unit, externally connected to a device incorporating the torque computation unit, for storing therein the predetermined torque reference values for outputting to the computation unit;

a tilt detector, provided inside the housing, for detecting whether the back side grip part is tilted at a predetermined angle with respect to the front side cover part in tightening operation; and

an error monitoring unit for causing the output unit to output a measurement error based on a detection result of the tilt detector.

6. The torque wrench as claimed in claim 5, comprising:

a setting unit for setting a tightening torque set value; and

a torque judgment unit for judging whether or not the torque measurement value shown by the computation result of the torque computation unit is close to/has reached the tightening torque set value as set through the setting unit, and causing the output unit to output the judgment result.

7. The torque wrench as claimed in claim 6, wherein the housing is provided with a lock mechanism for releasably locking the back side grip part to prevent tilting of the grip part with respect to the front side cover part.

8. The torque wrench as claimed in claim 7, wherein the lock mechanism is configured to include a lock member rotatably coupled to a back end part of the back side grip part, the lock member having a movement regulating long hole for inserting the back end part of the strain body thereinto.

9. The torque wrench as claimed in claim 5, wherein the housing is provided with a lock mechanism for releasably locking the back side grip part to prevent tilting of the grip part with respect to the front side cover part.

10. The torque wrench as claimed in claim 9, wherein the lock mechanism is configured to include a lock member rotatably coupled to a back end part of the back side grip part, the lock member having a movement regulating long hole for inserting the back end part of the strain body thereinto.

11. A torque wrench, comprising:

a tightening unit;

a strain body including a tip part for replaceably connecting the tightening unit thereto;

a housing;

a setting unit for selectively inputting a type of the tightening unit thereto;

a distortion sensor for detecting a distorted amount of the strain body corresponding to a tightening force of the tightening unit;

a torque computation unit, in which a plurality of predetermined torque reference values required for computing tightening torques of different types of tightening units and corresponding to effective lengths of the tightening units have been prepared in advance, for computing the tightening torque T=(R×

D) based on an appropriate one value R of the torque reference values that corresponds to the type of the tightening unit and a detection result D of the distortion sensor;

an output unit for outputting at least a computation result by the torque computation unit as a tightening torque measurement value; and

a memory unit, externally connected to a device incorporating the torque computation unit, for storing therein the predetermined torque reference values for outputting to the computation unit,

wherein said torque reference value R is determined by R=T0/D0, in which T0 is a tightening torque at a present reference weight, and D0 is an output value of said distortion sensor at said present reference weight,

wherein the strain body is accommodated in the housing,

wherein the housing has a two-divided structure including;

a front side cover part in a cylindrical shape for accommodating the tip part of the strain body, a tip face thereof having a hole for inserting a base end part of the tightening unit; and

a back side grip part in a cylindrical shape for accommodating a base end part of the strain body and having an axis, inside thereof, extending in a direction orthogonal to the tightening force of the tightening unit,

the strain body rotatably supported by the axis such that the back side grip part is capable of tilting slightly with respect to the front side cover part,

wherein the housing is provided with a lock mechanism for releasably locking the back side grip part to prevent tilting of the grip part with respect to the front side cover part.

12. The torque wrench as claimed in claim 11, wherein the lock mechanism is configured to include a lock member rotatably coupled to a back end part of the back side grip part, the lock member having a movement regulating long hole for inserting the back end part of the strain body thereinto.

13. A torque wrench, comprising:

a tightening unit;

a housing;

a strain body including a tip part for replaceably connecting the tightening unit thereto;

a setting unit for selectively inputting a type of the tightening unit thereto;

a distortion sensor for detecting a distorted amount of the strain body corresponding to a tightening force of the tightening unit;

a torque computation unit, in which a plurality of predetermined torque reference values required for computing tightening torques of different types of tightening units and corresponding to effective lengths of the tightening units have been prepared in advance, for computing the tightening torque based on an appropriate value of the torque reference values that corresponds to the type of the tightening unit and a detection result of the distortion sensor; and

an output unit for outputting at least a computation result by the torque computation unit as a tightening torque measurement value,

wherein the housing has a two-divided structure including;

a front side cover part in a cylindrical shape for accommodating the tip part of the strain body, a tip face thereof having a hole for inserting a base end part of the tightening unit; and

a back side grip part in a cylindrical shape for accommodating a base end part of the strain body and having an axis, inside thereof, extending in a direction orthogonal to the tightening force of the tightening unit,

wherein the strain body rotatably supported by the axis such that the back side grip part is capable of tilting slightly with respect to the front side cover part,

wherein the torque wrench further comprises;

a tilt detector, provided inside the housing, for detecting whether the back side grip part is tilted at a predetermined angle with respect to the front side cover part in tightening operation; and

an error monitoring unit for causing the output unit to output a measurement error based on a detection result of the tilt detector.

14. A torque wrench comprising:

a tightening unit;

a housing;

an axis;

a strain body including a tip part for replaceably connecting the tightening unit thereto;

a setting unit for selectively inputting a type of the tightening unit thereto;

a distortion sensor for detecting a distorted amount of the strain body corresponding to a tightening force of the tightening unit;

a torque computation unit, in which a plurality of torque reference values required for computing tightening torques of different types of tightening units and corresponding to effective lengths of the tightening units have been prepared in advance, for computing the tightening torque based on an appropriate value of the torque reference values that corresponds to the type of the tightening unit and a detection result of the distortion sensor; and

an output unit for outputting at least a computation result by the torque computation unit as a tightening torque measurement value,

wherein the housing includes;

a front side cover part in a cylindrical shape for accommodating the tip part of the strain body, a tip face thereof having a hole for inserting a base end part of the tightening unit; and

a back side grip part in a cylindrical shape for accommodating a base end part of the strain body,

wherein the axis is disposed inside the back side grip part and extends in a direction orthogonal to the tightening force of the tightening unit so as to pass through the strain body, and

wherein the back side grip part is capable of tilting slightly with respect to the front side cover part with the axis rotatably supporting the back side grip part.