JP2010249586A - Working machine, and device for measuring force of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost device for measuring the force of a working machine, accurately measuring the force regardless of the attitude of the working machine or the direction of the force. <P>SOLUTION: The device includes: a link mechanism 18 having a first link 16 attached to an attachment 23 via a rotation shaft 44 and a second link 17 bridged over the end of the first link and an arm 12; an attachment cylinder 15 attached to the link mechanism via a rotation shaft 45; a two-axial force detection device 42b provided to a rotation shaft 42 and detecting the forces in two axial directions orthogonal to each other; a one-axial force detection device 44b fixed to the first link to rotate integrally with the first link and detecting the force in one axial direction; angle sensors 40a, 41a, 42a detecting the attitude of the attachment; and an arithmetic unit 60 operating the force acting on the attachment based on the detection values from the two-axial force detection device, the one-axial force detection device and the angle sensors. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a work machine and a force measuring device for the work machine that measures a force acting on the attachment.

  As a work machine used for structural demolition work, waste demolition work, civil engineering construction work, etc., an upper work body is attached to the upper part of the lower traveling body, and an articulated work device (work front) is attached to this upper work body. The one that can be swung up and down is known. In such a working machine, a working device having a boom and an arm is connected to an upper working body so as to swing up and down, and an attachment (for example, a grapple, a bucket, a breaker, a crusher, etc.) is attached to the tip of the arm. is there.

  By the way, when an operation is performed using such an attachment, the force applied to the attachment changes in accordance with a change in load, generation of inertial force, contact with a structure, and the like. Under these conditions, it is required to accurately measure the force applied to the attachment in order to notify the operator and work manager of the work state, work throughput, etc., and to control the work machine. .

  In response to such a request, for example, it is possible to detect forces in two axial directions orthogonal to each other of a pin (arm side pin) that connects the arm and the attachment and a pin (link side pin) that connects the link and the attachment. There is a biaxial force detection device that detects the load on the attachment load by detecting the magnitude and direction of the load applied to the two pins with this biaxial force detection device (Japanese Patent Application Laid-Open No. 2002-277311). Etc.).

  Also, an interposition plate is provided between the tip of the working device (the tip of the arm) and the attachment, and a biaxial force detection device is provided on a pin connecting the interposition plate and the attachment. Provided with a uniaxial force detecting device capable of detecting a force in one axial direction at a connecting portion between the fitting body and the attachment. There is one in which a load of an attachment load is detected using a two-axis force detection device and a one-axis force detection device (see Japanese Patent Application Laid-Open No. 2006-112827).

Japanese Patent Application Laid-Open No. 2002-277311 JP 2006-1112827 A

  The former technique described in Japanese Patent Application Laid-Open No. 2002-277311 needs to prepare two biaxial force detection devices as described above, and thus manufacturing cost and measurement accuracy are problems. Furthermore, since it is necessary to process the detection signals for four axes output from the two two-axis force detection devices, the cost of preparing an amplifier capable of amplifying four detection signals (that is, detection signals for four channels) is also a problem. It becomes.

  On the other hand, in the latter technique described in Japanese Patent Application Laid-Open No. 2006-112827, it is necessary to provide an interposition plate, a fitting body, or the like as a new mechanism member at the tip of the working device (arm). Therefore, the increase in the cost by these members, the fall of the work capability accompanying the increase in the weight of the front-end | tip of a working apparatus, etc. become problems.

  Furthermore, considering the actual work, during work using the attachment, not only gravity but also inertial force, contact force with the structure, etc. are generated, so the direction of the force applied to the attachment changes every moment. . Therefore, the force measuring device needs to be able to measure forces in all directions.

  An object of the present invention is to provide a low-cost force measuring device for a work machine that can measure force with high accuracy regardless of the posture of the working device and the direction of force.

  In order to achieve the above object, the present invention provides a lower traveling body, an upper working body attached to the upper portion of the lower traveling body, a working device swingably attached to the upper working body, and the work A force measuring device for a working machine comprising an attachment attached to the tip of the device via a rotation shaft, a first link attached to the attachment via a rotation shaft at one end, this first link A link mechanism having a second link spanned between the other end of the link and the working device, and is attached to the link mechanism via a rotation shaft, and the attachment is rotated by extending and contracting. An attachment cylinder, and a biaxial force detection device that is provided on the rotation shaft for attaching the attachment to the working device and detects forces in two axial directions perpendicular to each other. A uniaxial force detection device that is fixed to the first link so as to rotate integrally with the first link and detects a force in a uniaxial direction; an attitude detection device that detects the orientation of the attachment; An arithmetic device that calculates a force acting on the attachment based on detection values from the biaxial force detection device, the uniaxial force detection device, and the posture detection device is provided.

  According to the present invention, one of the two force detection devices can be a uniaxial force detection device, and a new mechanism member is not added in that case. It is possible to provide a force measuring device for a work machine capable of measuring.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of a work machine provided with a force measuring device according to a first embodiment of the present invention.
The work machine 1 shown in this figure mainly includes a lower traveling body 2 that travels in contact with the ground and an upper working body 3 to which a working device 6 is attached.

  The lower traveling body 2 is of a so-called crawler type, and is a footwear 201 in contact with the ground, a drive wheel 202 that drives the footwear, a driven wheel 203 that is rotated by the footwear, and a structure 204 that supports these. Etc. Of course, the lower traveling body 2 may be configured as a so-called wheel type having a plurality of wheels.

  The upper working body 3 is attached to the upper part of the lower traveling body 2. The working machine 1 according to the present embodiment is a hydraulic excavator, and the upper working body 3 is connected to the lower traveling body 2 via a swivel device (not shown) so as to be able to swivel. You may attach to the traveling body 2. FIG.

  The work device (work front) 6 is swingably attached to the upper work body 3. An attachment 23 is attached to the distal end of the working device 6 (the distal end of an arm 12 described later) via a rotation shaft 42 so as to be rotatable. The working device 6 according to the present embodiment is rotatably attached to the boom 10 via a rotating shaft 41 and a boom 10 that is rotatably attached to the upper working body 3 via a rotating shaft 40. An arm 12 is provided, and an attachment 23 is attached to the tip of the arm 12 via a rotation shaft (arm side pin) 42.

  A link mechanism 18 is attached to the attachment 23 via a rotation shaft (link side pin) 44, and an end portion on the rod side of the attachment cylinder 15 is attached to the link mechanism 18 via a rotation shaft 45. Yes. The attachment cylinder 15 is a hydraulic cylinder, and rotates the attachment 23 around the rotation shaft 42 by expanding and contracting. In the work machine 1 shown in FIG. 1, a bucket is attached as the attachment 23. In addition to this, a work tool such as a grapple, a cutter, a breaker, or a magnet may be attached according to work.

  FIG. 2 is a detailed view of the periphery of the attachment 23 in the work machine of FIG. In addition, the same code | symbol is attached | subjected to the same part as the previous figure, and description is abbreviate | omitted (the following figure is also the same).

  The link mechanism 18 shown in this figure includes a first link 16 that spans between the rod-side tip of the attachment cylinder 15 and the attachment 23, and a rod-side tip of the attachment cylinder 15 and the arm 12. It has the second link 17 passed.

  The first link 16 is pivotally attached to the attachment 23 via a pivot shaft 44 at one end, and pivots to the attachment cylinder 15 via a pivot shaft 45 at the other end. It is attached as possible. Further, the second link 17 is rotatably attached to the arm 12 via a rotation shaft 46 at one end portion and is attached to the attachment cylinder 15 via a rotation shaft 45 at the other end portion. It is pivotally attached.

  In the present embodiment, the link mechanism 18 is configured by the two links of the first link 16 and the second link 17, but in addition to this, for example, the tip end portion on the rod side of the attachment cylinder 15 and the rotation shaft The fourth link is bridged between 45, and the fourth link is bridged between the tip of the rod side of the attachment cylinder 15 and the arm 12, so that four links (that is, the first link to the fourth link) are provided. The link mechanism 18 may be configured as described above. Further, the link mechanism 18 may be configured by more than four links.

  Returning now to FIG. The work machine 1 shown in FIG. 1 includes a boom angle sensor 40a, an arm angle sensor 41a, and an attachment angle sensor 42a as a posture detection device that detects the posture of the attachment 23. The boom angle sensor 40 a detects the rotation angle (relative angle) of the boom 10 with respect to the upper working body 3, and is provided on the upper working body 3 and the pivot shaft 40 of the boom 10. The arm angle sensor 41 a detects the rotation angle (relative angle) of the arm 12 with respect to the boom 10, and is provided on the pivot shaft 41 of the boom 10 and the arm 12. The attachment angle sensor 42 a detects the rotation angle (relative angle) of the attachment 23 with respect to the arm 12, and is provided on the rotation shaft 42 of the arm 12 and the attachment 23. In the present embodiment, based on the detection values of the boom angle sensor 40a, the arm angle sensor 41a, and the attachment angle sensor 42a, the computing device 60 (see FIG. 3 to be described later) determines the absolute angle θ of the attitude of the attachment 23 with respect to the horizontal plane ( The angle to the ground (see FIG. 4) is calculated.

Here, the rotation shaft 42 and the rotation shaft 44 will be described in detail.
The rotation shaft (arm-side pin) 42 is provided with a biaxial force detection device 42b that detects forces in two axial directions orthogonal to each other, and the rotation shaft 42 functions as a so-called pin type load cell. A pin type load cell is configured by attaching strain detection means (for example, a strain gauge, a strain sensor, etc.) to a surface corresponding to a force detection direction of a cylindrical pin (rotating shafts 42, 44). The magnitude of the shearing force applied to the pins (rotating shafts 42 and 44) is detected by measuring the strain generated in the strain detecting means. In the rotating shaft 42, in order to detect forces in two axial directions orthogonal to each other as described above, it is necessary to attach strain detecting means to at least two surfaces orthogonal to each other. However, in order to improve the measurement accuracy of the biaxial force detection device 42b, more strain detection means may be attached. Although the rotation shaft 42 of the present embodiment is fixed to the attachment 23 so as to rotate integrally with the attachment 23, the rotation shaft 42 corresponds to the arm 12 so as to rotate integrally with the arm 12. May be fixed.

  The rotating shaft (link side pin) 44 is provided with a uniaxial force detecting device 44b for detecting a force in one axial direction, and the rotating shaft 44 functions as a pin type load cell like the rotating shaft 42. Yes. In this embodiment, the direction of the force detected by the uniaxial force detection device 44b is the direction of the line segment connecting the rotation shaft 44 and the rotation shaft 45 (hereinafter, referred to as “longitudinal direction of the first link 16”). There are things). Therefore, the uniaxial force detection device 44b needs to be configured so that the force in the longitudinal direction of the first link 16 can always be detected regardless of the attitude of the first link. Therefore, in the present embodiment, the rotation shaft 44 provided with the uniaxial force detection device 44 b is fixed to the first link 16. When the rotation shaft 44 is fixed to the first link 16 in this way, the uniaxial force detection device 44b rotates integrally with the first link 16, so that the force detection direction is always the same as the longitudinal direction of the first link. Can be matched. In addition, as a specific method of fixing the rotation shaft 44 to the first link 16, for example, a through hole that penetrates the rotation shaft 44 and the first link 16 is provided, and a pin is fitted into the through hole. There is.

  FIG. 3 is a schematic configuration diagram of the force measuring apparatus according to the first embodiment of the present invention.

  The force measuring device shown in this figure includes a biaxial force detector 42b, a uniaxial force detector 44b, a boom angle sensor 40a, an arm angle sensor 41a, an attachment angle sensor 42a, an amplifier 64, and an arithmetic device 60. And a display device 61.

  The amplifier 64 includes detection signals 42bx, 42by (corresponding to detection signals for force Fax 'and force Fay' in FIG. 4 described later) output from the biaxial force detection device 42b and a uniaxial force detection device. Amplifying a detection signal 44bx (corresponding to a detection signal of force Fl in FIG. 4 described later) for one axis direction output from 44b, and connected to the two-axis force detection device 42b and the one-axis force detection device 44b. Yes. The detection signals 42bx, 42by, 44bx amplified by the amplifier 64 are output to the arithmetic unit 60.

  The arithmetic device 60 is connected to the amplifier 64 and the angle sensors 40a, 41a, 42a, and has a central processing unit (CPU) (not shown) and a storage device (not shown). The computing device 60 detects the posture of the attachment 23 based on the detection signals from the angle sensors 40a, 41a, 42a, and applies force to the attachment 23 based on the detection signals 42bx, 42by, 44bx from the force detection devices 42b, 44b. The size and direction of F are calculated.

  The display device 61 is connected to the calculation device 60 and displays the magnitude and direction of the force F calculated by the calculation device 60.

Next, a specific calculation method performed by the calculation device 60 will be described with reference to FIG.
FIG. 4 shows the force F applied to the attachment 23, the force Fa detected by the biaxial force detection device 42b, and the force Fl detected by the uniaxial force detection device 44b in the first embodiment of the present invention. It is a relationship diagram.

  As shown in this figure, first, as a reference coordinate system, the X axis is set in the front-rear direction of the work machine 1 and the Y axis is set in the vertical direction. Further, as a coordinate system of the attachment 23 (attachment coordinate system), an x ′ axis is set in a direction of a line segment connecting the rotary shaft 42 and the rotary shaft 44, and a y ′ axis is set in a direction perpendicular to the x ′ axis. Set. Here, it is assumed that when the force F acts on the point P23 in the attachment 23, the force Fa acts on the rotating shaft 42 and the force Fl acts on the rotating shaft 44.

At this time, two-axis force detection device 42b which is fixed to the attachment 23, the force Fa acting on the pivot shaft 42, and x 'axial force Fa _x', as y 'axial force Fa _y' To detect. Then, the biaxial force detection device 42b outputs the detection value of the force Fa _{x ′} as the detection signal 42bx and the detection value of the force Fa _{y ′} as the detection signal 42by to the arithmetic device 60 via the amplifier 64.

  On the other hand, the uniaxial force detection device 44 b fixed to the first link 16 detects the force Fl acting on the rotating shaft 44 as the force Fl acting on the longitudinal direction of the first link 16. Then, the uniaxial force detection device 44b outputs the detection value of the force Fl as a detection signal 44bx to the arithmetic device 60 via the amplifier 64.

Here, the computing device 60 calculates the angle α formed by the first link 16 and the x ′ axis based on the detection value of the attachment angle sensor 42a. As a specific method of calculating the angle α, the length of each side of a quadrangle having four pivot shafts 42, 44, 45, 46 as apexes (the length of each side is the respective pivot shafts 42, 44, 45). , 46 in advance) and α is calculated using the angle of the apex formed by the rotation shaft 42 in the quadrangle (that is, the detected value of the attachment angle sensor 42a). Then, the arithmetic unit 60, the x 'axis direction component F _x' of the force F and y 'axial component F _y' acting on the attachment 23, with Fa _{x ',} Fa _y', Fl, alpha, following Calculated from equation (1).

Further, the arithmetic device 60 determines the angle θ of the attachment 23 (the angle formed by the X axis and the x ′ axis) with respect to the horizontal plane (X axis), the boom angle sensor 40a, the arm angle sensor 41a, and the attachment angle sensor 42a (attitude detection device). ) Based on the detected value. The arithmetic device 60 uses the X-axis direction component F _X and the Y-axis direction component F _Y of the force F applied to the attachment 23 by using the above θ and F _{x ′} and F _{y ′} calculated from the equation (1). Then, it is calculated using the following formula (2). Thereby, the arithmetic unit 60 can calculate the magnitude and direction of the force F acting on the attachment 23.

  Next, the operation and effect of the present embodiment will be described.

  Since the attachment 23 in the present embodiment is connected to the work device 6 via the rotation shaft 42 and the rotation shaft 44, the force Fa acting on the rotation shaft 42 and the force Fl acting on the rotation shaft 44 are connected. Is balanced with the force F applied to the attachment 23. The attachment 23 is connected to the attachment cylinder 15 via the link mechanism 18, and the posture of the link mechanism 18 is determined by the force Fl acting on the rotation shaft 44. That is, the longitudinal direction of the first link 16 in the present embodiment always coincides with the direction of the force Fl acting on the rotation shaft 44.

  In response to this, the force measuring device for the working machine according to the present embodiment includes a uniaxial force detecting device 44b fixed to the first link 16, and the uniaxial force detecting device 44b is connected to the first link 16 and the first link 16. Rotate together. When the uniaxial force detection device 44b is provided in this way, the force detection direction of the uniaxial force detection device 44b and the longitudinal direction of the first link 16 can always coincide with each other. The force Fl can be measured only by providing 44b.

  That is, in the technique described in Japanese Patent Application Laid-Open No. 2002-277711, it is necessary to attach a two-axis force detection device to each of the two rotation shafts 42 and 44, but according to the present embodiment, Since the moving shaft 44 side can be used as the uniaxial force detection device 44b, the cost required for the force detection device can be reduced. In addition, this reduces the number of detection signals to be amplified by one, so that it is possible to use the amplifier 64 that is less expensive than the conventional one, thereby further reducing cost. Furthermore, since the number of detection signals to be subjected to arithmetic processing in the arithmetic device 60 is similarly reduced, errors due to interference are reduced, and the accuracy of force measurement can be improved.

  Further, the force measuring device of the present embodiment does not require an additional mechanism member as in the technique described in Japanese Patent Application Laid-Open No. 2006-112827 when using the uniaxial force detecting device 44b. Therefore, problems such as an increase in cost due to the mechanism member and a decrease in work capability due to an increase in the weight of the tip of the work device 6 do not occur. Moreover, since this embodiment does not require the mechanism member, it is also a great merit that it can be applied only by making some modifications to the existing work machine.

  As described above, according to the present embodiment, it is possible to provide a force measuring device for a work machine that can measure force with high accuracy and is low in cost.

Next, a second embodiment of the present invention will be described.
This embodiment is different from the first embodiment in a method for measuring the force Fl acting on the rotating shaft 44. In the first embodiment, the rotation shaft 44 provided with the one-axis force detection device 44b is fixed to the first link 16, but in this embodiment, the one-axis force detection device is attached to the first link 16 itself. Thus, the force Fl acting on the rotating shaft 44 is obtained.

  FIG. 5 is a detailed view of the periphery of the attachment 23 according to the second embodiment of the present invention.

  The first link 16 shown in this figure is attached with a uniaxial force detection device 16b for detecting a compressive force and a tensile force acting in the longitudinal direction of the first link 16 (that is, a force acting in a uniaxial direction). Yes. The biaxial force detection device 42b in the rotation shaft 42 is the same as that in the first embodiment.

  As a method of attaching the single axial force detection device 16b to the first link 16, for example, (I) a concave portion (or a through hole) is provided in the first link 16, and a single axial force is detected on the surface of the concave portion (or the through hole). There are those that are built into the first link 16 by attaching the device 16b, and (II) those that attach the one-axis force detection device 16b to the surface of the first link 16. In these cases, the uniaxial force detection device 16b may be attached to a plate member that easily transmits strain, and the plate member may be attached to the first link 16. In the case of (II), it is preferable to cover the uniaxial force detection device 16b with a cover in order to protect it from the outside.

  The uniaxial force detection device 16b may be configured by a strain detection means such as a strain gauge, similarly to the uniaxial force detection device 44b in the first embodiment.

FIG. 6 is a schematic configuration diagram of a force measuring apparatus according to the second embodiment of the present invention.
The force measuring device shown in this figure is the same as that of the first embodiment except that a uniaxial force detecting device 16b is connected to an amplifier 64 instead of the uniaxial force detecting device 44b.

  The detection signals 42bx and 42by from the biaxial force detection device 42b and the detection signal 16bx from the uniaxial force detection device 16b are amplified by the amplifier 64 and input to the arithmetic device 60. In the arithmetic device 60, the magnitude of the force F applied to the attachment 23 from the detection values of the two-axis force detection device 42b and the one-axis force detection device 16b and the detection values of the angle sensors 40a, 41a, 42a input via the amplifier 64. And direction are calculated. The calculated value is displayed on the display device 61.

  Here, a method of calculating the force F acting on the attachment 23 in the present embodiment will be described. Also in the present embodiment, as in the first embodiment, the direction of the force Fl acting on the rotating shaft 44 that connects the attachment 23 and the first link 16 always coincides with the longitudinal direction of the first link 16. To do. Therefore, the force detected by the uniaxial force detection device 16b can be regarded as being equal to Fl. Therefore, the arithmetic unit 60 can calculate the force F acting on the attachment 23 using the above formulas (1) and (2) as in the first embodiment.

  Therefore, also in the present embodiment, the magnitude and direction of the force F acting on the attachment 23 can be obtained by the biaxial force detector 42b and the uniaxial force detector 16b. Further, in the present embodiment, the first link 16 that is an existing member has a force detection function and does not require an additional mechanism member, so that the same effect as that of the first embodiment can be exhibited. .

  Furthermore, in the present embodiment, unlike the first embodiment, the uniaxial force detection device 16b is attached to the first link 16, so that even when the rotation shaft 44 has a backlash, it is affected. Highly accurate force measurement is possible. Further, according to the present embodiment, unlike the first embodiment, there is no need to fix the rotating shaft 44 to the first link 16, so that it is like a conventional work machine distributed in the market. The rotating shaft 44 can be fixed to the attachment 23. Therefore, since the replacement work of the attachment 23 does not change from the conventional one, there is a merit that the user who is used to the conventional replacement work does not feel uncomfortable.

  In each of the above-described embodiments, the example in which the angle sensors 40a, 41a, and 42a are used as the posture detection device that detects the posture of the attachment 23 has been described. However, the posture detection device may be configured by other devices. good. As specific examples, for example, (I) an inclination angle sensor 23a (see FIG. 2) for detecting the absolute angle of the posture of the attachment 23 with respect to the horizontal plane is attached to the attachment 23, or (II) the absolute angle of the arm 12 is detected. A tilt angle sensor 12a (see FIG. 2) that attaches to the arm 12, and an attachment angle sensor 42a that detects the rotation angle of the attachment 23 with respect to the distal end portion of the working device 6 (that is, the arm 12) is attached to the rotating shaft 42. There is.

  In each of the above-described embodiments, the case where the one-axis force detection devices 44b and 16b are attached to the link mechanism 18 including the two links 16 and 17 has been described. However, a link mechanism including more than two links can be attached. Needless to say, in the case of being connected to the link 23, the single-axis force detection device may be attached to the link directly connected to the attachment 23, as with the first link 16.

  By the way, in each of the above embodiments, a hydraulic excavator has been described as an example of the work machine. However, it goes without saying that the present invention is applicable to any work machine in which an attachment can be attached to the tip of the work device. Yes.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic of the working machine provided with the force measuring device which is the 1st Embodiment of this invention. FIG. 2 is a detailed view of the periphery of an attachment 23 in the work machine of FIG. 1. The schematic block diagram of the force measuring device which is the 1st Embodiment of this invention. The relationship diagram of the force F applied to the attachment 23 in the 1st Embodiment of this invention, and the force detected by force detection apparatus 42b, 44b. The detail drawing of the attachment 23 periphery part which concerns on the 2nd Embodiment of this invention. The schematic block diagram of the force measuring device which is the 2nd Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Work machine 2 Lower traveling body 3 Upper work body 6 Working apparatus 10 Boom 12 Arm 12a Inclination angle sensor 15 Attachment cylinder 16 First link 16a One axial force detection apparatus 17 Second link 18 Link mechanism 23 Attachment 23a Inclination angle sensor 23P Attachment Force acting point 40 Rotating shaft 40a Boom angle sensor 41 Rotating shaft 41a Arm angle sensor 42 Rotating shaft (arm side pin)
42a Attachment angle sensor 42b Biaxial force detector 44 Rotating shaft (link side pin)
44b Uniaxial force detection device 45 Rotating shaft 46 Rotating shaft 60 Arithmetic device 61 Display device 64 Amplifier

Claims (7)

A lower traveling body, an upper working body attached to an upper portion of the lower traveling body, a working device attached to the upper working body in a swingable manner, and a tip of the working device are attached via a rotation shaft. In a force measuring device for a work machine provided with an attachment,
A link having a first link attached to the attachment via a rotation shaft at one end portion, and a second link spanned between the other end portion of the first link and the working device. Mechanism,
An attachment cylinder that is attached to the link mechanism via a rotation shaft and rotates the attachment by extending and contracting;
A biaxial force detection device that is provided on the rotating shaft for attaching the attachment to the working device and detects forces in two axial directions orthogonal to each other;
A uniaxial force detection device that is fixed to the first link so as to rotate integrally with the first link and detects a force in a uniaxial direction;
An attitude detection device for detecting the attitude of the attachment;
And an arithmetic unit that calculates the magnitude and direction of the force acting on the attachment based on detection values from the two-axis force detection device, the one-axis force detection device, and the posture detection device. Force measuring device for work machines. In the working machine force measuring device according to claim 1,
The one-axis force detection device is provided on the rotating shaft for attaching the first link to the attachment,
The force measuring device for a working machine, wherein the rotation shaft for attaching the first link to the attachment is fixed to the first link. In the working machine force measuring device according to claim 1,
The uniaxial force detection device is attached to the first link, and is a force measuring device for a work machine. In the working machine force measuring device according to claim 1,
The work machine, wherein the posture detection device is an inclination angle sensor that detects an absolute angle of the posture of the attachment with respect to a horizontal plane. In the working machine force measuring device according to claim 1,
The posture detecting device is
An inclination angle sensor for detecting an absolute angle of the posture of the distal end portion of the working device with respect to a horizontal plane;
A work machine, comprising: an angle sensor that is provided on the rotation shaft for attaching the attachment to the work device and detects a rotation angle of the attachment with respect to a tip of the work device. In the working machine force measuring device according to claim 1,
The working device has a boom attached to the upper working body via a rotation shaft, and an arm attached to the boom via a rotation shaft,
The attachment is rotatably attached to the arm,
The posture detecting device is
A boom angle sensor provided on the pivot shaft for attaching the boom to the upper working body, and detecting a rotation angle of the boom with respect to the upper working body;
An arm angle sensor provided on the pivot shaft for attaching the arm to the boom, and detecting a rotation angle of the arm with respect to the boom;
A work machine comprising: an attachment angle sensor that is provided on the rotation shaft for attaching the attachment to the arm and detects a rotation angle of the attachment with respect to the arm. A lower traveling body,
An upper working body attached to the upper part of this lower traveling body,
A working device swingably attached to the upper working body;
An attachment attached to the tip of this working device via a rotation shaft;
A first link attached to the attachment via a rotation shaft, a link mechanism having a second link spanned between the first link and the working device;
An attachment cylinder that is attached to the link mechanism via a rotation shaft and rotates the attachment by extending and contracting;
A biaxial force detection device that is provided on the rotating shaft for attaching the attachment to the working device and detects forces in two axial directions orthogonal to each other;
A uniaxial force detection device that is fixed to the first link so as to rotate integrally with the first link and detects a force in a uniaxial direction;
An attitude detection device for detecting the attitude of the attachment;
And an arithmetic unit that calculates the magnitude and direction of the force acting on the attachment based on detection values from the two-axis force detection device, the one-axis force detection device, and the posture detection device. Work machine.

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