IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0574446
(1984-01-27)
|
발명자
/ 주소 |
- Morgan, Paul W.
- Ellwood, Thomas J.
- Amlani, Kish D.
- Hodges, John B.
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
7 인용 특허 :
1 |
초록
▼
The performance and condition of a tool, workpiece or machine tool is sensed during machining operations by securing a single or plural strain gages to the tool holder. To increase the sensitivity of the strain gages on stationary tool holders, the tool holders are contoured to provide locations of
The performance and condition of a tool, workpiece or machine tool is sensed during machining operations by securing a single or plural strain gages to the tool holder. To increase the sensitivity of the strain gages on stationary tool holders, the tool holders are contoured to provide locations of higher strain in which the strain gages are attached. A single or plural strain gages are positioned to sense the combined effect of different strains such as axial thrust and torque and are electrically connected to provide a single Wheatstone bridge output "signature" which may be monitored to detect a defective operation. In rotating tools, the single "signature" output greatly reduces the coupling equipment such as rotary transformers and also reduces the monitoring equipment. A unique arrangement of a single strain gage or alternatively a plurality of gages enables monitoring of both torque and thrust simultaneously. The output from the plurality of strain gages can be made additive to increase sensitivity and yet requires only a single bridge circuit. The design is flexible in that the gages may be arranged for optimization of the single bridge output for either torque or thrust.
대표청구항
▼
1. A torque and thrust sensor for machine tools of the type in which the machine provides a source of drive power to a tool, the tool being applied to the workpiece in order to perform work thereon, comprising: (a) a tool holder connected between the source of drive power and the tool to supply t
1. A torque and thrust sensor for machine tools of the type in which the machine provides a source of drive power to a tool, the tool being applied to the workpiece in order to perform work thereon, comprising: (a) a tool holder connected between the source of drive power and the tool to supply the drive power to the tool, the tool holder comprising: (i) a central axis running generally from the source of drive power to the tool, (ii) a first flange having its principal surface oriented generally orthogonal to the central axis of the tool holder, (iii) a second flange having its principal surface oriented generally orthogonal to the central axis of the tool holder and its principal surface positioned apart from and facing the principal surface of the first flange, (iv) a plurality of beams connected at one of their ends to the principal surface of the first flange and at their other ends to the principal surface of the second flange, the connection to the flanges being adjacent the periphery of the flanges and the beams each being connected at an angle phi with respect to the central axis for bending in response to torque or axial loading of the tool holder. (b) a strain gage device mounted on a beam and oriented to measure a desired strain in the beam produced by the operation of the tool on the workpiece. 2. A torque and thrust sensor as claimed in claim 1, wherein the beams join the principal surfaces of the flanges at a common radial distance. 3. A torque and thrust sensor as claimed in claim 1, wherein the strain gage device is comprised of a plurality of individual strain gages each mounted adjacent the junction of the beam and the principal surface of a flange. 4. A torque and thrust sensor as claimed in claim 1, wherein the strain gage device comprises a first set of two strain gages with one gage being mounted on one end of a first beam while the other is mounted on the opposite end of the same beam, but both are on the same surface of the beam and each is oriented parallel to the principal surfaces of the flanges, one strain gage sensing compression, while the other senses tension for either a torsional or a thrust load on the tool holder. 5. A torque and thrust sensor as claimed in claim 4, further comprising a second set of two strain gages with the first gage of the second set being mounted on the opposite side of the beam from the first strain gage of said first set and the second strain gage of the second set being mounted on the opposite side of the beam from the second gage of said first set, one of the gages in the second set measuring tension while the other measures compression and all four gages being connected in a Wheatstone bridge configuration in aiding fashion to produce a maximum output for either a torsional or thrust load on the tool holder. 6. A torque and thrust sensor as claimed in claim 1, wherein the angle of the beams with respect to the central axis is adjusted to optimize the output for the ratio of torque to thrust from the strain gages. 7. A torque and thrust sensor as claimed in claim 6 in which the strain gages on opposite ends of the beam are connected to a first set of opposite arms of a Wheatstone bridge circuit. 8. A torque and thrust sensor as claimed in claim 7 further comprising a second set of two additional strain gages connected to a second beam in a manner similar to that of the first set, the second set of strain gages being series connected into the remaining opposite arms of the Wheatstone bridge to complete the bridge circuit, and whereby said output comprises a single signal representing both torque and thrust. 9. A transducer for sensing the effects of axial and torsional loading and providing an electrical output indicative thereof comprising: (a) body means including first end means defining a first surface adapted for receiving input torsional and thrust loading about an axis, said body means further including second end means defining a reaction surface adapted for transmitting said input loading to a reaction member and elastically strainable structure disposed intermediate said first surface and said reaction surface, said strainable structure including gaging structure defining a sensing surface, said gaging structure defining the region of maximum stress in said strainable structure; (b) a single strain gage disposed on said sensing surface, said strain gage having the sensing direction thereof oriented at an acute angle in the range 15°-30° with respect to the axis of loading for sensing effects of combined torsion and thrust loading and, (c) bridge circuit means operative, upon connection to a source of electrical power, to apply an electrical potential to said strain gage and operative to detect changes in the resistance of said gage in response to said combined torsion and thrust loading of said transducer and operative to provide an output signal indicative of said loading. 10. The transducer defined in claim 9, wherein (a) said gaging structure comprises a plurality of spaced elongated beams each extending between said first and second end means; and, (b) said gaging surface comprises a portion of the surface of one of said beams adjacent an end thereof, said beams being deflected in bending upon application of said axial and torsion loading of said transducer except that said single gage has its sensing direction oriented longitudinally in the direction of elongation of said beam for sensing tension or compression, strains due to said bending. 11. The transducer defined in claim 10 further comprising a second strain gage disposed on said beam at substantially the same longitudinal station therealong and on the surface of said beam opposite said first single gage for sensing strains in the sense opposite said first single gage, said second gage electrically connected is said bridge circuit such that said bridge circuit detects the combined changes in resistance of said gages. 12. The trandsucer defined in claim 10, further comprising a plurality of strain gages, with a first pair of same mounted on one of said beams adjacent and on opposite sides the end thereof and a second pair of same disposed adjacent one end and on opposite sides of a second beam, with said pairs connected in said bridge circuit means such that said bridge circuit means detects the combined resistance change of the individual gages in each pair and provides a single electrical output indicative of all the resistance changes. 13. The transducer defined in claim 10, wherein said beams are circumferentially spaced generally axially extending and each subtend an acute angle with said loading axis. 14. The transducer defined in claim 10, wherein said beams are circumferentially spaced and each subtend an acute angle in the range 15°-45° with the said loading axis. 15. The transducer defined in claim 10 wherein said first end means includes a hub and said beams extend radially outwardly therefrom with said second end means including structure connected to the radially outward end of each of said beams. 16. The transducer defined in claim 9, wherein said strainable structure comprises an elongated generally cylindrical member and said gaging structure comprises a reduced transverse section or necked portion. 17. The transducer defined in claim 16, wherein a plurality of gages are substituted for said single gage, having one of said gages disposed with is sensing direction oriented substantially parallel to said loading axis, a second gage disposed with its sensing direction oriented generally at transversely to said loading axis and spaced on said gaging surface by a quadrant from said first gage, a third gage disposed to have its sensing direction at an acute angle of substantially 45° with said loading axis and a fourth gage also having its sensing direction at 45° spaced diametrically opposite of said third gage, said first and second gages electrically connected such that said bridge circuit means senses the combined change in resistance thereof and said third and fourth gages electrically connected such that said bridge circuit means senses the combined change in resistance therof. 18. The transducer defined in claim 9, further comprising a second strain gage also oriented at 15°-30° to said loading axis and disposed in spaced quadrature from said first single gage, said second gage operatively connected to said bridge circuit means electrically in parallel with said output. 19. A torque and thrust sensor for machine tools of the type in which the machine provides a source of drive power for a tool, the tool being applied to a workpiece to perform work thereon, comprising: (a) a tool holder connected between the source of drive power and the tool to supply the drive power to the tool, the tool holder including an extended portion which spans the distance between its connection to the tool and its connection to the source of drive power, said extended portion having a central axis running generally through the central area of the tool holder from its connection to the source of drive power to its connection to the tool and containing a reduced cross-sectional area that is not greater than its cross-sectional area at its connection to the source of drive power and at its cross-sectional area at its connection to the tool; and (b) a plurality of strain gage devices mounted to the tool holder in the extended area, said strain gage devices individually oriented and electrically connected to produce a combined signal representing torque and thrust strains in the tool holder produced by the operation of the tool on the workpiece. 20. A torque and thrust sensor as claimed in claim 19 in which the individual strain gages are series connected for producing a combined output signal. 21. A torque and thrust sensor as claimed in claim 19, in which the individual strain gages are parallel connected for producing a combined output. 22. A torque and thrust sensor for a machine tool of the type in which the machine provides a source of drive power to a workpiece, the tool being held fixed, while the workpiece is applied to the tool in order to perform work on the workpiece, comprising: (a) a tool holder connected between the machine and the tool to hold the tool in a fixed position, the tool holder including an extended portion which spans the distance between its connection to the tool and its connection to the machine, said extended portion having a central axis running generally through the central area of the tool holder in the direction from its connection to the machine to its connection to the tool and containing a reduced cross-sectional area that is not greater than its cross-sectional area at its connection to the tool and is not greater than the cross-sectional area at its connection to the source of drive power; and (b) a plurality of strain gage devices mounted to the tool holder in the extended area, said strain gage devices individually oriented and electrically connected to produce a combined signal representing torque and thrust strains in the tool holder produced by the operation of the tool on the workpiece. 23. A torque and thrust sensor as claimed in claim 22, wherein a first number of the individual strain gages are oriented parallel to the central axis of the holder and a second number of the individual strain gages are oriented orthogonal to the central axis of the tool holder. 24. A torque sensor as claimed in claim 23, in which a third number of individual strain gages are oriented parallel to the central axis of the tool holder, a fourth number are oriented perpendicular to the central axis of the strain gage and a fifth number are oriented at nominally 45 degrees to the central axis of the tool holder.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.