JP2013064623A - Force sensor, force detection device, robot hand, robot, and force sensor manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve manufacturing efficiency while ensuring accuracy in positioning piezoelectric components in a horizontal direction.SOLUTION: In piezoelectric element holding plates 110 are formed multiple insertion holes 110h. In the insertion holes are respectively inserted guide components 112 each shaped to have a hollow therein. Further, the piezoelectric element holding plates 110 are stacked. Then, through hollow portions of the guide components 112 are respectively inserted pressure bolts 114 so that an upper component 102 is connected to a lower component 104. This allows pressure to be applied to the piezoelectric element holding plates 110 (piezoelectric elements). Each hollow portion of the guide components 112 is arranged to be smaller than an external diameter of the pressure bolts 114 so that inserting the pressure bolts 114 expands the guide components 112 to bring them into contact with the insertion holes. Upon stacking of the piezoelectric element holding plates 110, this arrangement enables the stacking quickly due to space provided between the insertion holes and the guide components. Further, after stacking, this arrangement enables positioning of the piezoelectric element holding plates 110 with good accuracy due to the guide components 112 being expanded by the pressure bolts 114 inserted.

Description

  The present invention relates to a force sensor, a force detection device, a robot hand, a robot, and a method for manufacturing the force sensor.

  2. Description of the Related Art A force sensor that detects a force by utilizing a piezoelectric effect exhibited by a specific crystal such as quartz or a specific ceramic is widely known. In this force sensor, a plurality of piezoelectric members may be stacked in order to increase output sensitivity.

  When a crystal such as quartz is used as the piezoelectric member, the applied force component can be decomposed and detected by the anisotropy of the piezoelectric effect depending on the crystal orientation. In such a force sensor, a plurality of piezoelectric members may be stacked in order to be able to measure force components in multiple directions.

  The load applied to these force sensors is mainly supported by the piezoelectric member. For this reason, when a plurality of piezoelectric members are stacked, if the position of the piezoelectric members in the horizontal direction (direction perpendicular to the stacking direction) is shifted, the area of the piezoelectric member that receives the load decreases, resulting in a decrease in output sensitivity. In addition, the piezoelectric member is destroyed due to stress concentration. Therefore, for example, in Patent Document 1, a plurality of piezoelectric members are prevented from being displaced in the horizontal direction by stacking thin annular members having an annular shape while positioning them on the inner peripheral side surface of the case.

JP 2006-17579 A

  However, the proposed technique has a problem that it is difficult to improve the manufacturing efficiency of the force sensor without impairing the horizontal positioning accuracy of the piezoelectric member. That is, if the gap between the piezoelectric member and the inner peripheral side surface of the case is made small in order to ensure the horizontal positioning accuracy of the piezoelectric member, a plurality of piezoelectric members can be inserted and stacked in the case. Since it becomes difficult, the manufacturing efficiency of the force sensor decreases. Therefore, if the gap between the piezoelectric member and the inner peripheral side surface of the case is widened so that a plurality of piezoelectric members can be easily stacked in the case, the horizontal positioning accuracy of the piezoelectric member is lowered. For these reasons, there has been a problem that it is difficult to simultaneously satisfy the request for improving the positioning accuracy of the piezoelectric member in the horizontal direction and the request for improving the manufacturing efficiency of the force sensor.

  The present invention has been made to solve at least a part of the above-described problems of the prior art, and improves the manufacturing efficiency of the force sensor while sufficiently securing the horizontal positioning accuracy of the piezoelectric member. The purpose is to provide technology that can be used.

In order to solve at least a part of the problems described above, the force sensor of the present invention employs the following configuration. That is,
A force sensor in which a plurality of stacked piezoelectric elements are sandwiched between a lower member and an upper member and are pressurized by a pressurizing bolt,
A plurality of guide members formed in a hollow shape by an elastic material and erected on the lower member;
A plurality of insertion holes through which the guide member is inserted, and a piezoelectric element holding plate in which the piezoelectric elements are provided between the plurality of insertion holes,
The lower member and the upper member are configured to pass through the hollow portion of the guide member in a state where the plurality of piezoelectric element holding plates stacked with the guide member inserted through the plurality of insertion holes are sandwiched. It is characterized by being fastened to each other using bolts.

Moreover, the manufacturing method of the force sensor of the present invention corresponding to the force sensor described above is as follows.
A method of manufacturing a force sensor in which a plurality of stacked piezoelectric elements are sandwiched between a lower member and an upper member and are pressurized by a pressurizing bolt,
A first step of standing a plurality of guide members formed in a hollow shape by an elastic material at a predetermined position of the lower member;
A second step of laminating a plurality of piezoelectric element holding plates, each having a plurality of insertion holes formed therein and having the piezoelectric elements provided between the plurality of insertion holes, by inserting the guide member into the plurality of insertion holes. When,
A third step of placing the upper member on the plurality of stacked piezoelectric element holding plates;
A fourth step of inserting the pressurizing bolt having a larger shaft diameter than the hollow portion of the guide member into the hollow portion of the guide member from a bolt hole provided in the upper member;
And a fifth step of fastening the upper member and the lower member using the pressurizing bolt.

  In the force sensor of the present invention having such a configuration, or the force sensor manufactured by the manufacturing method of the present invention, a plurality of piezoelectric element holding plates provided with piezoelectric elements are laminated, and an upper member, a lower member, In a state of being sandwiched between the two, it is pressurized by a pressurizing bolt. A plurality of insertion holes are formed in the piezoelectric element holding plate, and the plurality of piezoelectric element holding plates are stacked by inserting a guide member through the insertion hole and then passing through a pressurized bolt into a hollow portion of the guide member. And the lower member are fastened.

  If it carries out like this, in the step which laminates a plurality of piezoelectric element holding plates, it can be laminated quickly, positioning a plurality of piezoelectric element holding plates by passing the penetration hole of a piezoelectric element holding plate through a guide member. Then, after the piezoelectric element holding plates are stacked, a plurality of piezoelectric element holding plates (and piezoelectric elements) can be pressurized with the pressurizing bolts as they are by passing the pressurizing bolts through the hollow portions of the guide member. it can. Therefore, the force sensor of the present invention or the force sensor manufactured by the manufacturing method of the present invention can be efficiently manufactured while accurately positioning a plurality of piezoelectric element holding plates (and piezoelectric elements). .

  In the force sensor of the present invention described above, the hollow portion of the guide member may be formed smaller than the outer diameter of the pressurizing bolt. Then, when the pressurizing bolt is passed through the hollow portion in a state where the guide member is inserted through the insertion hole of the piezoelectric element holding plate, the guide member is spread by the pressurizing bolt, and the outer side of the guide member comes into contact with the insertion hole. You may do it.

  In this way, at the stage of stacking the plurality of piezoelectric element holding plates, the guide member is not spread out by the pressurizing bolt, so that a gap is formed between the insertion hole of the piezoelectric element holding plate and the guide member. For this reason, a plurality of piezoelectric element holding plates can be quickly stacked. After the piezoelectric element holding plate is laminated, when the pressurizing bolt is passed through the hollow portion of the guide member, the guide member is spread and comes into contact with the insertion hole of the piezoelectric element holding plate. As a result, the stacked piezoelectric element holding plates can be positioned with higher accuracy.

Further, in the above-described force sensor of the present invention, a plurality of electrode plates each having a plurality of insertion holes formed in the same manner as the piezoelectric element holding plate are alternately laminated with the piezoelectric element holding plate, so that the guide member is an insulating material. You may make it form by.
If it carries out like this, even if the guide member expanded through the pressurizing volt | bolt contacts an electrode plate, it can avoid that electrode plates electrically short-circuit.

In the above-described force sensor of the present invention, the piezoelectric element is provided for the three axes of the x, y, and z directions orthogonal to each other, and the x direction piezoelectric element having sensitivity to the force in the x direction is provided. Piezoelectric element holding plate, piezoelectric element holding plate provided with a y-direction piezoelectric element sensitive to y-direction force, and piezoelectric element holding plate provided with a z-direction piezoelectric element sensitive to z-direction force May be configured so that the force in the triaxial direction can be detected.
If it does in this way, it will become possible to detect the force of a triaxial direction with one force sensor.

Further, the force detection device of the present invention may be provided with two or more force sensors as described above to detect a moment around a desired axis.
In this way, it is possible to easily detect not only the axial force component but also the moment around the axis.

The force sensor of the present invention may be mounted on a robot hand or a robot.
Usually, a robot hand or robot is equipped with a large number of force sensors. However, as described above, the force sensor of the present invention has piezoelectric elements positioned with high accuracy and is laminated, and is manufactured efficiently. Therefore, it is particularly excellent as a force sensor mounted on a robot hand or a robot.

It is the disassembled perspective view which showed the structure of the force sensor of a present Example. It is explanatory drawing which showed typically the electrical connection relation of the some quartz crystal element and electrode plate which comprise a force sensor. It is explanatory drawing which showed the method of laminating | stacking, positioning the some quartz crystal piezoelectric element with the force sensor of a present Example. It is a perspective view which shows the external appearance shape of the sleeve of a modification. It is a perspective view which shows the external appearance shape of the force detection apparatus provided with four force sensors. It is explanatory drawing which shows the robot hand and robot which mount the force detection apparatus of a present Example.

Hereinafter, in order to clarify the contents of the present invention described above, examples will be described in the following order.
A. Force sensor configuration:
B. Force sensor operation:
C. Quartz piezoelectric element positioning method:
D. Force detector:

A. Force sensor configuration:
FIG. 1 is an exploded perspective view showing the structure of the force sensor 100 of the present embodiment. As shown in FIG. 1, the force sensor 100 is formed by alternately laminating a plurality of electrode plates 106 and fluororesin spacers 110 provided with crystal piezoelectric elements 108 between an upper plate 102 and a lower plate 104. It is configured. For the electrode plate 106, a metal having conductivity, for example, a simple substance or an alloy such as titanium, aluminum, copper, or iron can be used. For example, stainless steel can be used as the iron alloy, and it is preferably used because of its excellent durability and corrosion resistance. A square through hole is opened in the center of the fluororesin spacer 110, and the quartz crystal element 108 having a square outer peripheral shape is disposed in the through hole, so that the crystal piezoelectric element 108 is positioned in the xy plane. Is done. In this embodiment, the upper plate 102 corresponds to the “upper member” in the present invention, and the lower plate 104 corresponds to the “lower member” in the present invention. The fluororesin spacer 110 corresponds to the “piezoelectric element holding plate” in the present invention.

  Two bolt holes 116 are opened in the upper plate 102. Each fluororesin spacer 110 has two circular insertion holes 110h. Similarly, each electrode plate 106 is also provided with two circular insertion holes 106h. On the other hand, between the upper plate 102 and the lower plate 104, two fluororubber sleeves 112 having a cylindrical pipe shape are arranged. When the electrode plates 106 and the fluororesin spacers 110 are stacked between the upper plate 102 and the lower plate 104, respectively, two circular insertion holes 106h and 110h provided in the electrode plate 106 and the fluororesin spacer 110, respectively. In addition, the two sleeves 112 are laminated so as to be inserted through each. Since the plurality of fluororesin spacers 110 are guided by the sleeve 112 through the two insertion holes 110h, they are stacked while being roughly positioned. Then, two pressurizing bolts 114 are inserted into the bolt holes 116 from above the upper plate 102, penetrate the sleeve 112, and are screwed into the lower plate 104. As will be described in detail later, by inserting the pressurizing bolt 114 into the sleeve 112, the plurality of fluororesin spacers 110 are positioned with higher accuracy (therefore, the quartz piezoelectric element 108 of the fluororesin spacer 110 is also positioned with higher accuracy. ), By screwing the upper plate 102 and the lower plate 104 using the bolt holes 116, the positioned crystal piezoelectric element 108 is pressurized with a constant force in the z direction. In this embodiment, the sleeve 112 corresponds to the “guide member” in the present invention.

  FIG. 2 is an explanatory diagram schematically showing an electrical connection relationship between the plurality of crystal piezoelectric elements 108 and the electrode plate 106 constituting the force sensor 100. As shown in FIG. 2, between the upper plate 102 and the lower plate 104, precisely, seven electrode plates 106a to 106g and six crystal piezoelectric elements 108a to 108f are laminated. Of the seven electrode plates 106a to 106g, the electrode plates 106b, 106d, and 106f are each connected to an output signal line. The electrode plates 106a, 106c, 106e, and 106g are grounded.

  On the other hand, among the six crystal piezoelectric elements 108a to 108f, the two middle crystal piezoelectric elements 108c and 108d are crystal piezoelectric elements (z-direction crystal piezoelectric elements) that are sensitive to the force in the compression direction, that is, the z direction. is there. The X direction of the crystal is along the z direction as indicated by the arrow, and the quartz crystal element 108c located above and the quartz crystal element 108d located below are opposite to each other. The lower two crystal piezoelectric elements 108e and 108f are crystal piezoelectric elements (x-direction crystal piezoelectric elements) having sensitivity to the force in the x direction in the horizontal direction. The X direction of the crystal is along the x direction as shown by the arrow, and the upper quartz piezoelectric element 108e and the lower quartz piezoelectric element 108f are opposite to each other. The upper two crystal piezoelectric elements 108a and 108b are crystal piezoelectric elements (a crystal piezoelectric element for y direction) having sensitivity to a force in the y direction in the horizontal direction. The X direction of the quartz crystal is along the y direction as indicated by a symbol, and the quartz crystal element 108a located above and the quartz crystal element 108b located below are opposite to each other.

B. Force sensor operation:
When a force is applied to the force sensor 100, the upper plate 102 and the lower plate 104 receive the force and transmit the force to the crystal piezoelectric elements 108a to 108f. Each of the quartz crystal piezoelectric elements 108a to 108f detects a force component corresponding to the crystal orientation of the quartz crystal by the piezoelectric effect. That is, as shown in FIG. 2, in the y-direction crystal piezoelectric elements 108a and 108b, as described above, since the X direction of the crystal is along the y direction, the force component in the y direction is detected, and the detected value is The electric signal based on this is output as an Fy signal from the electrode plate 106b to the output signal line. Similarly, in the crystal piezoelectric elements 108c and 108d for z direction, since the X direction of the crystal is along the z direction, a force component in the z direction is detected, and an electric signal based on the detected value is used as an Fz signal. Output to the output signal line from 106d. In the x direction crystal piezoelectric elements 108e and 108f, since the X direction of the crystal is along the x direction, a force component in the x direction is detected, and an electric signal based on the detected value is output as an Fx signal from the electrode plate 106f. Output to the signal line.

  As is apparent from the operation principle of the force sensor 100, the crystal orientation of the x-direction crystal piezoelectric elements 108e and 108f is accurately oriented in the x direction, and the crystal of the y-direction crystal piezoelectric elements 108a and 108b. If the azimuth is not accurately oriented in the y direction, force components in the x and y directions cannot be detected with high accuracy. Further, since a large force is applied to the crystal piezoelectric element 108, if the positions of the crystal piezoelectric elements 108a to 108f are shifted in the horizontal direction (xy direction), stress concentration is likely to occur in the crystal piezoelectric element 108, and the force sensor 100. When a force is applied to the quartz piezoelectric element 108, the crystal piezoelectric element 108 may be destroyed. Therefore, it is necessary to stack the crystal piezoelectric elements 108 while accurately positioning them so that the crystal orientations of the crystal piezoelectric elements 108a to 108f are in the correct direction and the positions of the crystal piezoelectric elements 108a to 108f are not shifted. is there. Therefore, the force sensor 100 of the present embodiment positions the quartz crystal piezoelectric element 108 by the following method.

C. Quartz piezoelectric element positioning method:
FIG. 3 is an explanatory view showing a method of laminating a plurality of crystal piezoelectric elements 108 while positioning them with the force sensor 100 of this embodiment. As described above, the quartz crystal piezoelectric element 108 is fitted in almost the center of the fluororesin spacer 110, and the fluororesin spacer 110 is formed with insertion holes 110h on both sides of the quartz crystal piezoelectric element 108 (see FIG. 1). When assembling the force sensor 100, a plurality of fluororesin spacers 110 and electrode plates 106 are alternately stacked while a sleeve 112 standing on the lower plate 104 is inserted into the insertion hole 110h. Then, the upper plate 102 is mounted, and the upper plate 102 and the lower plate 104 are fastened with the pressurizing bolts 114. FIG. 3A shows a state where a plurality of fluororesin spacers 110 and electrode plates 106 are alternately stacked on the lower plate 104.

  As shown in FIG. 3A, the fluororesin spacer 110 and the electrode plate 106 are stacked while being guided by the sleeve 112. Here, the inner diameter of the insertion hole 110 h of the fluororesin spacer 110 is formed to be larger than the outer diameter of the sleeve 112 by about 0.2 mm to 1 mm. For this reason, since the sleeve 112 can be easily inserted into the insertion hole 110h, a plurality of fluororesin spacers 110 can be quickly stacked. Further, the inner diameter of the insertion hole 106h of the electrode plate 106 is formed larger than the inner diameter of the insertion hole 110h. For this reason, a plurality of electrode plates 106 can also be stacked quickly.

  When all the fluororesin spacers 110 and the electrode plates 106 are stacked, the upper plate 102 is placed thereon, and then the pressurizing bolts 114 are inserted from the bolt holes 116 provided in the upper plate 102. Then, the pressurizing bolt 114 is inserted through the hollow portion 112h of the sleeve 112 until the screw hole 104h of the lower plate 104 is reached. FIG. 3B shows a state where the pressurizing bolt 114 is inserted into the hollow portion 112 h of the sleeve 112.

  Here, the inner diameter of the hollow portion 112 h of the sleeve 112 is formed slightly smaller than the outer diameter of the pressurizing bolt 114. For this reason, when the pressurizing bolt 114 is inserted into the hollow portion 112h of the sleeve 112, the outer diameter of the sleeve 112 is slightly increased. The outer diameter and inner diameter of the sleeve 112 when the pressurizing bolt 114 is not inserted are set such that the outer diameter of the sleeve 112 becomes equal to the inner diameter of the insertion hole 110h when the pressurizing bolt 114 is inserted. Is set. For this reason, when the pressurizing bolt 114 is inserted, the sleeve 112 presses the inner side of the insertion hole 110h in a direction in which the plurality of roughly positioned fluororesin spacers 110 are corrected so as to be positioned with higher accuracy. In addition, the fluororesin spacer 110 is not yet in a pressurized state only by inserting the pressurizing bolt 114 into the hollow portion 112 h of the sleeve 112. For this reason, the fluororesin spacer 110 moves with the force pressed from the sleeve 112 and is positioned with high accuracy (see FIG. 3B). Then, by tightening the pressurizing bolt 114 in a state where the plurality of fluororesin spacers 110 are accurately positioned, the plurality of fluororesin spacers 110 are pressurized between the upper plate 102 and the lower plate 104. .

  As described above, the force sensor 100 of the present embodiment is laminated while roughly positioning the fluororesin spacer 110 with the sleeve 112 as a guide. Since the positioning at the time of lamination may be rough, a plurality of fluororesin spacers 110 can be quickly laminated. When the pressurizing bolt 114 is inserted into the hollow portion 112h of the sleeve 112 in order to pressurize the plurality of laminated fluororesin spacers 110, the position of the fluororesin spacer 110 that has been roughly positioned is corrected by the sleeve 112. Thus, the state is more accurately positioned. In this state, the fluororesin spacer 110 (and the crystal piezoelectric element 108) is pressurized by the pressurizing bolt 114. For this reason, the force sensor 100 in which the fluororesin spacer 110 (and the crystal piezoelectric element 108) is positioned with high accuracy can be rapidly manufactured.

  In the above-described embodiment, the sleeve 112 is described as being formed of fluororubber. However, the sleeve 112 is formed using a material other than fluororubber as long as it is elastic and has an insulating property. May be. However, since the pressurizing bolt 114 is inserted into the hollow portion 112h of the sleeve 112, it is desirable to use a material (a material having a small friction coefficient) that allows the pressurizing bolt 114 to slide, such as fluororubber.

  In the above-described embodiment, the outer diameter of the sleeve 112 is made equal to the inner diameter of the insertion hole 110h when the pressurizing bolt 114 is inserted. However, since the sleeve 112 is formed of an elastic material, it may be slightly larger than the inner diameter of the insertion hole 110h (for example, about 10 μm to 50 μm in diameter). In this way, the sleeve 112 does not come into contact with the insertion hole 110h even if the pressurizing bolt 114 is inserted due to manufacturing variations of the insertion hole 110h of the fluororesin spacer 110, the sleeve 112, and the pressurizing bolt 114. Occurrence of a situation where the fluororesin spacer 110 cannot be positioned can be avoided.

  In the above-described embodiments, the sleeve 112 has been described as being formed in a tube shape having a circular cross section. However, the sleeve 112 may have a shape in which protrusions are provided on the outer peripheral surface or the inner peripheral surface. Of course, you may provide a some protrusion in each of an outer peripheral surface and an inner peripheral surface. For example, if a plurality of protrusions 112a are provided on the outer peripheral surface as in the sleeve 112 of the modification shown in FIG. 4A, the protrusion 112a is inserted when the pressurizing bolt 114 is inserted into the hollow portion 112h. Abut and press the insertion hole 110h. In this way, when the insertion hole 110h is strongly pressed, the protrusion 112a is deformed before the fluororesin spacer 110 is deformed, so that the fluororesin spacer 110 is not damaged.

  Alternatively, when a plurality of protrusions 112b are provided on the inner peripheral surface like the sleeve 112 of the modified example shown in FIG. 4B, the contact surface with the pressurizing bolt 114 becomes small. The bolt 114 can be easily inserted into the hollow portion 112h. Further, when the pressurizing bolt 114 is inserted, a portion where the protrusion 112b is provided on the inner peripheral surface bulges outward and presses the insertion hole 110h. For this reason, even if a portion where the insertion hole 110h is strongly pressed occurs, the outer peripheral surface of the sleeve 112 or the protrusion 112b is deformed, and the fluororesin spacer 110 is not damaged. .

D. Force detector:
FIG. 5 is a perspective view showing an appearance of a force detection device 200 including four force sensors 100 shown in FIG. As shown in FIG. 5, in the force detection device 200, the upper plate 102 and the lower plate 104 each have a disk shape and are shared by the force sensors 100 a to 100 d. The force sensors 100a to 100d are arranged 90 degrees apart from each other along the circumference, and the three or more force sensors 100 are arranged so as not to line up on the same straight line.

  As described above, the force sensor 100 can detect a force applied to the force sensor 100 in a state where the force sensor 100 is decomposed into force components in the xyz direction. Therefore, the force detection device 200 can detect a moment in one direction by combining any two force sensors 100. Moreover, since the force detection device 200 uses three or more force sensors 100 and is arranged so that the force sensors 100 do not line up on the same straight line, the force in the triaxial direction and the moment about the triaxial direction Can be detected simultaneously.

  The force sensor 100 and the force detection device 200 according to the present embodiment have been described above. However, the present invention is not limited to all the embodiments described above, and can be implemented in various modes without departing from the scope of the present invention. It is.

For example, in the embodiment described above, quartz is used as the piezoelectric material constituting the piezoelectric element, but the present invention is not limited to this. As the piezoelectric material, in addition to quartz, titanate ceramics such as lead zirconate titanate (PZT) and barium titanate (BaTiO ₃ ), lithium niobate (LiNbO ₃ ), and zinc oxide (ZnO) are preferable. Used for.

  Further, as illustrated in FIG. 6, the robot hand 300 or the robot 400 may be configured using the force detection device 200 of the present embodiment. Since the force detection device 200 of the present embodiment can measure not only the axial force but also the moment about the axis, it is possible to realize a small and high-performance robot hand or robot.

100 ... force sensor, 100a-d ... force sensor, 102 ... upper plate,
104 ... Lower plate, 104h ... Screw hole, 106 ... Electrode plate,
106a-g ... electrode plate, 106h ... insertion hole, 108 ... crystal piezoelectric element,
108a-f ... quartz crystal element, 110 ... fluororesin spacer,
110h ... insertion hole, 112 ... sleeve, 112a, b ... ridge,
112h ... hollow part, 114 ... pressure bolt, 116 ... bolt hole,
200 ... Force detection device, 300 ... Robot hand, 400 ... Robot

Claims (8)

A force sensor in which a plurality of stacked piezoelectric elements are sandwiched between a lower member and an upper member and are pressurized by a pressurizing bolt,
A plurality of guide members formed in a hollow shape by an elastic material and erected on the lower member;
A plurality of insertion holes through which the guide member is inserted, and a piezoelectric element holding plate in which the piezoelectric elements are provided between the plurality of insertion holes,
The lower member and the upper member are configured to pass through the hollow portion of the guide member in a state where the plurality of piezoelectric element holding plates stacked with the guide member inserted through the plurality of insertion holes are sandwiched. A force sensor characterized by being members that are fastened together using bolts. The force sensor according to claim 1,
In the guide member, the hollow portion is formed smaller than the outer diameter of the pressurizing bolt, and the pressurizing portion is inserted into the hollow portion in a state where the guide member is inserted into the insertion hole of the piezoelectric element holding plate. When the bolt is passed, the force sensor is pushed and spread by the pressurizing bolt and comes into contact with the insertion hole. The force sensor according to claim 1 or 2,
A plurality of insertion holes through which the plurality of guide members are inserted, and a plurality of electrode plates stacked alternately with the plurality of piezoelectric element holding plates;
The force sensor, wherein the guide member is made of an insulating material. A force sensor according to any one of claims 1 to 3,
With respect to the three axes of the x, y, and z directions orthogonal to each other, the piezoelectric element holding plate includes a piezoelectric element holding plate provided with an x direction piezoelectric element sensitive to a force in the x direction, and a y direction A three-axis direction including a piezoelectric element holding plate provided with a y-direction piezoelectric element having sensitivity to force and a piezoelectric element holding plate provided with a z-direction piezoelectric element having sensitivity to z-direction force A force sensor characterized by detecting the force of. A force detection device for detecting an applied force,
A force detection device comprising two or more force sensors according to claim 4 and detecting a moment about a desired axis.   A robot hand equipped with the force sensor according to any one of claims 1 to 4.   A robot equipped with the force sensor according to any one of claims 1 to 4. A method of manufacturing a force sensor in which a plurality of stacked piezoelectric elements are sandwiched between a lower member and an upper member and are pressurized by a pressurizing bolt,
A first step of standing a plurality of guide members formed in a hollow shape by an elastic material at a predetermined position of the lower member;
A second step of laminating a plurality of piezoelectric element holding plates, each having a plurality of insertion holes formed therein and having the piezoelectric elements provided between the plurality of insertion holes, by inserting the guide member into the plurality of insertion holes. When,
A third step of placing the upper member on the plurality of stacked piezoelectric element holding plates;
A fourth step of inserting the pressurizing bolt having a larger shaft diameter than the hollow portion of the guide member into the hollow portion of the guide member from a bolt hole provided in the upper member;
And a fifth step of fastening the upper member and the lower member using the pressurizing bolt.

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