JP2010066181A6 - Force and torque detection mechanism - Google Patents

Abstract

A force and torque detection mechanism having a simple structure and high accuracy and sensitivity is provided.
An area in which an intermediate ring is provided between an outer peripheral rim and a shaft boss, and a force applied to the outer rim is detected between the intermediate ring and the shaft boss. Secure. A plurality of trapezoidal columnar small arms 16 to 19 that sequentially change in cross section in the radial direction for connecting the intermediate ring 15 and the shaft boss 6 are provided in the region. The intermediate ring 11, the small arms 16-19, and the shaft boss 6 are integrated. By such a mechanism, the force applied to the outer peripheral rim 5 is transmitted to the intermediate ring 15 via the intermediate arms 11 to 14. The intermediate ring 15 transmits the force applied to the outer peripheral rim 5 evenly to the small arms 16 to 19. Further, a uniform high stress state is generated in the force detection region of the trapezoidal column type small arms 16 to 19. Using the force detection region, the force applied to the outer peripheral rim 5 is detected with high sensitivity and high accuracy.
[Selection] Figure 1

Description

  The present invention relates to a mechanism for detecting force and torque acting on a shaft.

  According to Japanese Patent Laid-Open No. 3-15468 and Japanese Patent Laid-Open No. 6-304205, as torque detection devices used for electric wheelchairs, etc., an operation torque generated when a user operates a hand rim is determined between a wheel and a hand rim. An invention (prior art 1) is disclosed in which a strain gauge is mounted between each other and measured, and a current corresponding to this operating force is supplied to the drive motor to generate an assist drive force.

  Also, the force applied to the hand rim using the load cell (conventional technology 2), the hand rim and the wheel are elastically engaged, and the difference between the rotation angles caused by the torque is detected. For detecting torque from the above (conventional technology 3, Japanese Patent Laid-Open No. 7-136218).

Further, as a torque detection device, a wheel hub that supports a wheel, a hand rim hub that is positioned concentrically with the wheel hub and that can rotate relatively, and a hollow cylindrical shape that is movable along the wheel hub and a rotation axis. There has also been proposed a device that includes a slider and detects torque by mounting a position sensor that detects the position of the slider (Prior Art 4, Japanese Patent Laid-Open No. 9-311085). None of these prior arts enables a highly accurate detection of force or torque with a simple structure.
JP-A-3-15468 JP-A-6-304205 JP-A-7-136218 JP-A-9-311085

Kazuaki Sakai, Toshihiko Yasuda, Naoyuki Kawakubo, and Katsuyuki Tanaka “Study on Operating Torque Detection Mechanism for One-Handed Wheelchairs” The Japan Society of Mechanical Engineers Kansai Branch 084-1 12-26 2008

  In the above prior arts 1 to 4, it is necessary to install a load cell, an angle detection device, a position sensor, and the like between the wheel and the hand rim, and the torque detection mechanism becomes large and complicated. Such a torque detection mechanism cannot be used when the installation location is narrow. In view of such a problem, an object of the present invention is to provide a means capable of detecting force and torque with high accuracy with a simple mechanism without requiring complicated components.

  In order to solve the above problems, in claim 1, in the mechanism for transmitting force to the shaft, an intermediate ring installed between the outer peripheral rim on which the force acts and the shaft boss integrated with the shaft; A plurality of force detecting small arms connecting the intermediate ring and the shaft boss, and detecting the amount of deformation of the surface portion of the force detecting small arm. A mechanism for detecting a working force or torque is provided.

  According to a second aspect of the present invention, in the cross section perpendicular to the radius of the intermediate ring of the small arm for force detection according to the first aspect, the position of the cross section changes from the shaft portion toward the outer peripheral portion. By forming a substantially trapezoidal columnar shape having a rectangular cross section in which the area of the cross section of the small arm decreases sequentially, a force detection region with uniform stress or deformation is generated on the surface portion of the small arm for force detection. The force detection area has a structure capable of detecting the force applied to the outer peripheral rim without depending on the stress detection position or the deformation amount detection position.

  The method of adjusting the thickness or width of the intermediate ring according to claim 1 so that the deformation of the intermediate ring is minimized, or the material of the intermediate ring is a material that minimizes the deformation of the intermediate ring. The outer ring portion is restrained from being deformed when a force is applied to the outer ring rim by a method such as setting the position of the intermediate ring near the outside of the shaft boss. Regardless of the point of action of the force applied to the rim, the stress state on the surface of the small arm for force detection or the deformation state of the small arm for force detection should be substantially equal in all the small arms for force detection. Therefore, a force or torque acting on the shaft integrated with the shaft boss can be detected without depending on the point of application of the force applied to the outer peripheral rim. And wherein the door.

  According to a fourth aspect of the present invention, the installation of the intermediate ring according to the first aspect has a function of adjusting a stress distribution or a deformation amount distribution in a stress measurement region or a deformation amount measurement detection region installed inside the intermediate ring. And

  According to a fifth aspect of the present invention, the torque acting on the shaft attached to the shaft boss can be detected from the force detected by the small arm for detecting force.

  According to the first invention, the third invention, and the fourth invention, when a force is applied to the outer peripheral rim, all the devices installed in the vicinity of the shaft portion are not dependent on the position of the point of application of the force. On the surface of the small force detection arm, a stress measurement region or deformation amount measurement region is generated in which the stress distribution or deformation amount distribution is substantially the same as the other force detection small arm surfaces. Thus, by installing a force such as a strain gauge or a deformation amount detection device in the stress measurement region or the deformation amount measurement region, without depending on the position of the point of application of the force applied to the outer peripheral rim, The force applied to the outer peripheral rim can be detected.

  According to the second invention, an area where the stress or deformation amount is uniform can be generated in the small arm for force detection by the force applied to the outer peripheral rim, thereby measuring the stress or deformation amount. The range of selection of the installation position of the detection device to perform is widened, and it is possible to accurately measure the force applied to the outer rim without requiring accuracy of the installation position of the detection device of force or deformation amount. . Therefore, even if there is a deviation in the affixing position due to the artificial work of affixing the gage or the like, a sufficient affixing region that can detect the same strain amount can be secured. For this reason, variation in the detected force is reduced. In addition, since the size of the cross-sectional area can be changed as appropriate, necessary and sufficient force detection sensitivity can be obtained.

  According to the fifth invention, it is possible to derive the torque acting on the shaft from the force acting on the outer peripheral rim detected by the stress detecting device or the deformation amount detecting device installed on the small arm for detecting force.

  According to the first invention, the second invention, the third invention, the fourth invention and the fifth invention, the force and torque acting on the shaft can be reduced by a simple mechanism installed in the vicinity of the shaft without providing a complicated mechanism. It can be detected.

  According to the first invention, the second invention, the third invention, and the fourth invention, the detection area of the force applied to the outer peripheral rim can be ensured in the immediate outer portion in the vicinity of the shaft boss that is the shaft mounting portion.

  According to the first invention, the second invention, the third invention, the fourth invention and the fifth invention, a mechanism for detecting the force and torque acting on the shaft is installed near the outside of the shaft having a large shaft diameter such as a hollow shaft. be able to.

  According to the first invention, the second invention, the third invention, the fourth invention, and the fifth invention, a new force or deformation amount detection area is formed inside the intermediate ring by the installation of the intermediate ring. Detection by reducing the variation in the stress state on the surface of the small arm for detecting force due to the difference in the installation position of the small arm for detecting force installed in the detection region of the force or deformation amount This has the effect of reducing the variation in stress. With this effect, the number of installed force detection small arms, the mounting position of the small force detection arm, and the size of the small force detection arm can be arbitrarily set. Furthermore, since the cross section of the shape of the small arm for detecting the force installed in the detection region of the force or deformation amount inside the intermediate ring can be designed with any size, the detection sensitivity and detection region of the force or deformation amount can be increased. Can be adjusted arbitrarily. Further, since both the front and back surfaces and the side surfaces of the small arm for force detection have a smooth flat surface, it is easy to attach a strain gauge or the like.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the force and torque detection mechanism includes force detection small arms 16 to 19 having a force and torque detection unit, and an intermediate ring 15 that adjusts the stress state of the force and torque detection unit. Composed.

  As shown in FIG. 1, the intermediate ring 15 of the force and torque detection mechanism is provided between the outer peripheral rim 5 and the shaft boss 6, and between the intermediate ring 15 and the shaft boss 6. The trapezoidal columnar small arms 16 to 19 for force detection are provided.

  The force and torque detection mechanism of the present invention shown in FIG. 1 is constructed stepwise from the conventional mechanism shown in FIG. 2 by the process shown in FIG.

  In the conventional mechanism shown in FIG. 2, when an operating force F acts on the outer peripheral rim 5, the stress state generated in the arms 1 to 4 as shown in FIG. Due to the difference in the relative position of F, as shown in FIG. The arm position in FIG. 5 is indicated by a position number obtained by equally dividing the arm between the shaft boss 6 and the outer peripheral rim 5. FIG. 5 shows the FEM analysis results when the operating force F is applied to the position shown in FIG.

  By installing the intermediate ring 15 shown in FIG. 6, the stress state generated in the force detection small arms 7 to 10 is operated with the force detection small arms 7 to 10 as shown in FIGS. Regardless of the difference in the relative position of the force F, they are substantially equal as shown in FIG. FIG. 9 shows the effect of the intermediate ring 15 in which the variation in the stress state generated in the force detection small arms 7 to 10 is reduced by providing the intermediate ring 15. FIG. 9 shows the FEM analysis results when the operating force F is applied to the position shown in FIG.

  FIG. 10 shows a substantially trapezoidal columnar force detection small arm for generating a uniform stress distribution region or a uniform deformation amount distribution region on the surface of the force detection small arms 16 to 19 of FIG.

  FIG. 1 shows a handle mechanism equipped with the force and torque detection mechanism of the present invention in which the substantially trapezoidal columnar force detection small arms 16 to 19 of FIG. 10 are installed between the intermediate ring 15 and the shaft boss 6. Show. When the operating force F is applied to the position shown in FIG. 11, a uniform stress state is generated in the small arm for force detection as shown in FIGS. In FIG. 13, the intermediate ring 15 is provided, and the force detection small arms 16 to 19 are substantially trapezoidal columnar force detection small arms, so that they are uniform and similar to the substantially trapezoidal force detection small arms 16 to 19. It is shown that the stress distribution is generated. FIG. 13 shows the FEM analysis results when the operating force F is applied to the position shown in FIG.

  The outer peripheral rim 5, the middle arms 11 to 14, the intermediate ring 15, the substantially trapezoidal force detection small arms 16 to 19 and the shaft boss 6 shown in FIG. 1 are integrated. Thereby, it can utilize as a hand rim which has a force and a torque detection mechanism.

  As shown in FIG. 14, by integrating the three types of elements of the intermediate ring 15, the force detecting small arms 16 to 19 and the shaft boss 6 shown in FIG. It is possible to form a torque detection unit that can be easily attached. The torque detection unit is an example of an embodiment of the present invention that facilitates connection of an intermediate arm and a torque detection mechanism.

  FIG. 15 is completed so that the torque detection unit shown in FIG. 14 can be used as a hand rim having a torque detection mechanism by connecting the rim and middle arm which are part of the hand rim.

  According to the above-described embodiment, a torque detection mechanism can be easily constructed in the vicinity of a drive rotation shaft of a mechanical device or the like, and can be used as a highly reliable operation force detection mechanism with few errors.

  16 is provided with a mechanism of the present invention as shown in FIG. 16 on the hand rims 24 to 26 of the one-handed wheelchair having three hand rims shown in FIG. It can be an operating mechanism.

  As shown in FIG. 17, by providing the valve handle with the mechanism of the present invention, the present invention can also be applied to the use of detecting the operating torque generated in the valve rod when the valve is opened and closed.

It is a figure which shows an example of the handle mechanism provided with the force and torque detection mechanism part in this invention. It is a figure which shows an example of the conventional handle mechanism. It is explanatory drawing which shows a mode that the force and torque detection mechanism part which concerns on this invention is formed in a shaft part of the handle | steering-wheel mechanism shown in FIG. 2 in steps. FIG. 3 is a schematic diagram showing a stress state generated in the intermediate arm 1 when an operating force F acts on the conventional handle mechanism shown in FIG. 2. FIG. 3 is a diagram showing a relationship between a maximum principal stress generated in an arm of the handle mechanism shown in FIG. 2 and an arm position. FIG. 2 is a view in which an intermediate ring is provided on the handle mechanism shown in FIG. 1 as a first stage of mechanism formation in the present invention. FIG. 7 is a schematic diagram showing a stress state generated in the intermediate arm 1 and the force detection small arms 7 to 10 when an operating force F is applied to the handle mechanism that has been improved in the first stage shown in FIG. 6. It is an enlarged view of the stress state which arises in the small arms 7-10 for force detection near the axial part of the handle mechanism shown in FIG. It is a figure which shows the relationship between the largest principal stress which arises in the intermediate | middle arm 1 of the handle mechanism disclosed in FIG. 6, and the small arms 7-10 for force detection, and an arm position. FIG. 5 is a diagram of a small arm for force detection having a quasi-equal strength shaped cross section in which the cross section sequentially changes in the radial direction of the intermediate ring 15; It is a schematic diagram which shows the stress state which arises in the intermediate | middle arm 1 and the force detection small arms 16-19 when the operating force F acts on the handle mechanism shown in FIG. It is an enlarged view of the stress state which arises in the small arms 16-19 for force detection near the axial part of the handle mechanism shown in FIG. It is a figure which shows the relationship between the largest principal stress which arises in the intermediate | middle arm 1 of the handle mechanism shown in FIG. 10, and the small arms 16-19 for force detection, and an arm position. It is a figure which shows the torque detection unit which shows the Example of this invention. It is a figure which shows the handle mechanism with a torque detection mechanism which used the unit for torque detection of FIG. 14 for the handle mechanism. It is the figure which utilized the handle mechanism of FIG. 15 which shows embodiment of this invention for the wheelchair for one hand as a hand rim. It is the figure which built this embodiment of this invention in the handle | steering-wheel part which opens and closes a valve | bulb.

Explanation of symbols

1 Arm 1
2 Arm 2
3 Arm 3
4 Arm 4
5 Outer rim 6 Shaft boss 7 Force detection small arm 1
8 Small arm for force detection 2
9 Small arm for force detection 3
10 Small arm for force detection 4
11 Intermediate Arm 1
12 Intermediate Arm 2
13 Intermediate Arm 3
14 Intermediate Arm 4
15 Intermediate ring 16 Small trapezoidal force detection arm 1
17 Small trapezoidal force detection arm 2
18 Small trapezoidal force detection arm 3
19 Small trap 4 for trapezoidal force detection
20 Strain gauge 21 Torque detection mechanism unit rim 22 Torque detection mechanism unit 23 Torque detection mechanism unit mounting arm 24 Left hand rim 25 Straight hand rim 26 Right hand rim 27 Handle

Claims (5)

In the mechanism for transmitting the force to the shaft, an intermediate ring installed between the outer peripheral rim on which the force acts and the shaft boss integrated with the shaft, and a plurality of connecting the intermediate ring and the shaft boss A force detecting small arm, and a mechanism for detecting a force or torque acting on the shaft by detecting a deformation amount of a surface portion of the force detecting small arm. Feature force and torque detection mechanism. In the cross section orthogonal to the radius of the intermediate ring of the small arm for force detection according to claim 1, the cross section of the small arm for force detection when the position of the cross section changes from the shaft portion toward the outer peripheral portion. By generating a substantially trapezoidal column shape having a rectangular cross section in which the area of the force decreases successively, a force detection region having a uniform stress or deformation amount is generated on the surface portion of the small force detection arm, and the force detection region The force and torque detection mechanism according to claim 1, wherein the force and torque detection mechanism has a structure capable of detecting a force applied to the outer peripheral rim without depending on a stress detection position or a deformation amount detection position. A method of adjusting the thickness or width of the intermediate ring according to claim 1 so that deformation of the intermediate ring is minimized, or a method of using the material of the intermediate ring as a material that minimizes deformation of the intermediate ring, The deformation of the intermediate ring when a force is applied to the outer peripheral rim is suppressed by a method such as setting the installation position of the intermediate ring near the outside of the shaft boss, and the force applied to the outer peripheral rim is reduced. By making the stress state of the surface of the small arm for force detection or the deformation state of the small arm for force detection substantially equal in all the small arms for force detection without depending on the point of action, the shaft portion It is characterized by having a structure capable of detecting the force or torque acting on the shaft integrated with the boss without depending on the point of application of the force applied to the outer peripheral rim. Force and torque detection mechanism according to claim 1. 2. A function of adjusting a stress distribution or a deformation amount distribution in a stress measurement region or a deformation amount measurement detection region installed inside the intermediate ring by installing the intermediate ring according to claim 1. The force and torque detection mechanism described in 1. The force and torque detection mechanism according to claim 1, wherein a torque acting on the shaft attached to the shaft boss can be detected from a force detected by the small arm for force detection.