JP4640113B2 - Displacement detection device - Google Patents

Description

  The present invention relates to a displacement amount detection device that detects a relative displacement amount of two members that undergo relative displacement.

  As an apparatus for detecting the relative displacement amount of the two members that are relatively displaced, for example, there is one using a strain gauge (see, for example, Patent Document 1). Here, the strain gauge has anisotropy. Therefore, the relative displacement amount in the predetermined direction can be detected by arranging the strain gauge so that the relative displacement amount in the direction to be detected can be detected.

Conventionally, a rubber sensor in which conductive particles such as metal powder are dispersed in rubber is known (see, for example, Patent Document 2). When this rubber sensor is compressed, the dispersed conductive particles come close to each other, so that the resistance value of the rubber sensor becomes small. On the other hand, when the rubber sensor is pulled, the conductive particles are separated, so that the resistance value of the rubber sensor increases. Thus, it is supposed that the physical quantity of the member to which the rubber sensor is attached can be detected by utilizing the fact that the resistance value of the rubber sensor varies depending on the state of the rubber sensor.
JP-A-2005-134220 JP-A-4-283602

  However, unlike a strain gauge, a viscoelastic member such as a rubber sensor does not have anisotropy. That is, in the case where the rubber sensor undergoes, for example, compression deformation or tensile deformation, it cannot be determined in which direction the compression deformation or tensile deformation has occurred. Therefore, when the two members are relatively displaced in a plurality of directions, even if a conventional rubber sensor is used, the relative displacement amount in the specific direction of the two members cannot be detected.

  This invention is made in view of such a situation, and provides the displacement amount detection apparatus which can detect the relative displacement amount of two members to be displaced relatively using viscoelastic members, such as a rubber sensor. For the purpose.

In the displacement amount detection device of the present invention, the second member is disposed away from the first member, and the second member is relative to the first member in a predetermined axial direction among three orthogonal axes from the reference position. It is possible to displace and at least one relative displacement in relative movement and relative rotation in an axial direction different from a predetermined axial direction among the three orthogonal axes, and the second member is moved from the reference position with respect to the first member. A displacement amount detection device for detecting a relative displacement amount in a predetermined direction from a reference position of a second member with respect to a first member in the case of relative displacement in a predetermined axial direction, comprising: a first conductive viscoelastic member; 2 conductive viscoelastic members, a Wheatstone bridge circuit, a power source, a detector, and a deformation absorber .

Here, the first conductive viscoelastic member has a first member and a second member elastically coupled, Ri Do a conductive viscoelastic material whose impedance varies according to the deformation, with respect to the first member it is a member you tensile deformation or compression deformation when the second member is relatively displaced from the reference position to the predetermined axis direction. The first conductive viscoelastic member is, for example, a material in which conductive particles such as metal powder are dispersed in a viscoelastic member. The viscoelastic material is rubber, silicon, elastomer, gel or the like.

The second conductive viscoelastic member, the first member and the second member elastically coupled so as to be parallel with the first conductive viscoelastic member, the conductive viscous impedance changes according to the deformation Made of elastic material. Furthermore, the second conductive viscoelastic member is resistant to tensile and compressive deformation of the first conductive viscoelastic member when the second member is relatively displaced from the reference position in the predetermined axial direction with respect to the first member. This is a member that undergoes anti-symmetric tensile compression deformation. Here, the reverse symmetry of tensile deformation means compression deformation, and the reverse symmetry of compression deformation means tensile deformation. That is, when the first conductive viscoelastic member undergoes tensile deformation, the second conductive viscoelastic member is compressed and deformed. Further, when the first conductive viscoelastic member is compressively deformed, the second conductive viscoelastic member is tensile deformed.

  The Wheatstone bridge circuit is a circuit formed by the impedance of the first conductive viscoelastic member and the second conductive viscoelastic member. Here, the Wheatstone bridge circuit is a circuit formed by four impedances. Specifically, it comprises a first half bridge circuit in which a first impedance and a third impedance are connected in series, and a second half bridge circuit in which a second impedance and a fourth impedance are connected in series. The first half bridge and the second half bridge are connected in parallel. Furthermore, an intermediate point between the first impedance and the third impedance and an intermediate point between the second impedance and the fourth impedance are connected. Two impedances selected from the first to fourth impedances are the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member. In the above description, the impedance is referred to. When an alternating current flows, the impedance is used. However, when a direct current flows, the impedance corresponds to a resistance. That is, the impedance in the present invention is a concept including a resistance when a direct current flows.

  The power supply applies a bridge input voltage to the Wheatstone bridge circuit. In other words, the power supply applies a bridge input voltage to both ends of the first half bridge circuit and the second half bridge circuit constituting the Wheatstone bridge circuit. This power source may be a DC power source or an AC power source.

The detection unit detects a relative displacement amount in the predetermined axial direction from the reference position of the second member with respect to the first member based on the bridge output voltage of the Wheatstone bridge circuit. Here, the bridge output voltage is a voltage difference between an intermediate point between the first impedance and the third impedance and an intermediate point between the second impedance and the fourth impedance. That is, the detection unit detects a relative displacement amount in the predetermined direction from the reference position of the second member with respect to the first member based on the voltage difference.
The deformation absorber is between the first member and / or the second member and the first conductive viscoelastic member, and between the first member and / or the second member and the second conductive viscoelastic member. And a spring constant smaller than that of the first conductive viscoelastic member and the second conductive viscoelastic member.
Then, the second conductive viscoelastic member and the first conductive viscoelastic member are disposed to face the first conductive viscoelastic member in a predetermined axial direction so as to sandwich the second member.

The displacement amount detection apparatus configured as described above operates as follows. First, when the first member and the second member are relatively displaced, the first conductive viscoelastic member and the second conductive viscoelastic member undergo tensile deformation. In particular, when the second member is relatively displaced in the predetermined axial direction with respect to the first member, one of the first conductive viscoelastic member and the second conductive viscoelastic member is tensilely deformed and the other is compressed. Deform. That is, in this case, the impedance of the conductive viscoelastic member that undergoes tensile deformation increases. On the other hand, the impedance of the conductive viscoelastic member that undergoes compressive deformation is reduced.

  Here, as described above, the bridge output voltage of the Wheatstone bridge circuit is a voltage difference between an intermediate point between the first impedance and the third impedance and an intermediate point between the second impedance and the fourth impedance. The two impedances selected from the first to fourth impedances are the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member.

Therefore, when the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member change in magnitude, the bridge output voltage of the Wheatstone bridge circuit changes. Based on the bridge output voltage that changes in this way, the detection unit can detect the amount of relative displacement in the predetermined axial direction from the reference position of the second member relative to the first member.

On the other hand, when the second member is relatively displaced with respect to the first member in a direction different from the predetermined axial direction described above, both the first conductive viscoelastic member and the second conductive viscoelastic member are The same deformation may occur. For example, the first conductive viscoelastic member and the second conductive viscoelastic member may both undergo tensile deformation or compressive deformation together. In this way, when both the first conductive viscoelastic member and the second conductive viscoelastic member are deformed in the same manner, the respective impedances change in the same manner. That is, the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member do not change different from each other. In this case, the bridge output voltage of the Wheatstone bridge circuit can be prevented from changing.

When the second member is relatively displaced with respect to the first member in a direction different from the predetermined axial direction , the first conductive viscoelastic member and the second conductive viscoelastic member do not deform the same. In some cases. Even in such a case, the change in the bridge output voltage when the second member is relatively displaced in the predetermined axial direction with respect to the first member, and the second member is in the predetermined axial direction with respect to the first member. A change in the bridge output voltage in the case of relative displacement in different directions behaves differently.

Thus, in any case described above, the bridge output voltage when the second member is relatively displaced in the predetermined axial direction with respect to the first member, and the second member is the predetermined axis with respect to the first member. The bridge output voltage in the case of relative displacement in a direction different from the direction exhibits different behaviors. Therefore, by using the bridge output voltage exhibiting such behavior, the relative displacement amount of the second member relative to the first member in the predetermined axial direction can be extracted.
In particular, the second conductive viscoelastic member and the first conductive viscoelastic member are arranged to face the first conductive viscoelastic member in a predetermined axial direction so as to sandwich the second member. I have to. That is, the second member is disposed between one end side of the first conductive viscoelastic member and one end side of the second conductive viscoelastic member. The other end side of the first conductive viscoelastic member and the other end side of the second conductive viscoelastic member are connected to the first member. Further, a straight line connecting the first conductive viscoelastic member and the second conductive viscoelastic member is set to a predetermined axial direction.
Accordingly, when the second member is relatively displaced in the predetermined axial direction with respect to the first member, either the first conductive viscoelastic member or the second conductive viscoelastic member is surely compressed and deformed. And the other undergoes tensile deformation. Therefore, when the second member is displaced relative to the first member in the predetermined axial direction, the difference between the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member changes. . When the second member is displaced relative to the first member in a direction perpendicular to the predetermined axis, the first conductive viscoelastic member and the second conductive viscoelastic member are deformed in the same manner. Therefore, when the second member is displaced relative to the first member in a direction perpendicular to the predetermined axis, the difference between the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member. Does not change. Furthermore, even when the second member rotates about a predetermined axis or about an axis orthogonal to the predetermined axis with respect to the first member, the first conductive viscoelastic member and the second conductive viscoelastic member are deformed in the same manner. do. Therefore, even when the second member rotates about the predetermined axis or about the axis orthogonal to the predetermined axis with respect to the first member, the impedance of the first conductive viscoelastic member and the second conductive viscoelastic member The difference from the impedance does not change.
That is, by arranging the second member between the first conductive viscoelastic member and the second conductive viscoelastic member, the second member is located in a direction other than the predetermined axial direction with respect to the first member. Even in the case of relative displacement in the direction, the relative displacement amount in the predetermined axial direction from the reference position of the second member relative to the first member can be reliably detected. That is, the relative displacement in the predetermined axial direction from the reference position of the second member relative to the first member is detected without being affected by the relative displacement in the direction other than the predetermined axial direction with respect to the first member. can do.
Further, by providing the deformation absorbing material, when the second member is largely displaced with respect to the first member, the deformation absorbing material is greatly deformed, and the first conductive viscoelastic member and the second conductive material are deformed. The amount of deformation of the viscous viscoelastic member can be reduced. In particular, when the second member is displaced in a direction other than the predetermined axial direction with respect to the first member, it is possible to reduce the influence of the first conductive viscoelastic member and the second conductive viscoelastic member. . Then, by making the spring constant of the deformation absorbent smaller than the spring constant of the first conductive viscoelastic member and the second conductive viscoelastic member, the deformation of the deformation absorbent is changed to the first conductive viscoelastic member. The elastic member and the second conductive viscoelastic member can be hardly affected. Accordingly, it is possible to more reliably detect the relative displacement amount in the predetermined axial direction from the reference position of the second member with respect to the first member to be detected.

  Here, in the Wheatstone bridge circuit, the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member may be as follows.

  First, when the second member is located at the reference position with respect to the first member, the impedance of the second conductive viscoelastic member is substantially the same as the impedance of the first conductive viscoelastic member. Further, the Wheatstone bridge circuit includes a first half bridge circuit and a second half bridge circuit described below. The first half-bridge circuit is a circuit in which the impedance of the first conductive viscoelastic member and the third impedance are connected in series. The second half-bridge circuit connects in series the impedance of the second conductive viscoelastic member and the fourth impedance that is substantially the same impedance as the third impedance. Further, the second half-bridge circuit is connected in parallel to the first half-bridge circuit so that the impedance of the second conductive viscoelastic member and the impedance of the first conductive viscoelastic member are directly connected. Furthermore, an intermediate point between the impedance of the second conductive viscoelastic member and the fourth impedance of the second half bridge circuit is connected to an intermediate point between the impedance of the first conductive viscoelastic member and the third impedance. The In this case, the power source applies a bridge input voltage to both ends of the first half bridge circuit and the second half bridge circuit, and the bridge output voltage is set between the first half bridge circuit and the second half bridge circuit. It is assumed that the voltage difference is a point.

  As a result, the difference between the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member appears directly in the voltage difference that is the bridge output voltage. Here, when the second member is relatively displaced in the predetermined direction with respect to the first member, the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member are as described above. Each changes differently. Therefore, when the second member is displaced relative to the first member in a predetermined direction, the bridge output voltage has a very large value. On the other hand, when the second member is displaced relative to the first member in a direction different from the predetermined direction, the bridge output voltage has a relatively small value. Therefore, by using such a bridge output voltage, it is possible to reliably extract the amount of relative displacement of the second member with respect to the first member in the predetermined direction.

  Further, when the detection unit detects the relative displacement amount in the predetermined axial direction from the reference position of the second member with respect to the first member, the first conductive viscoelastic member and the second conductive viscoelastic member are: It is preferable to have substantially the same impedance when substantially the same deformation is performed. Thereby, the difference between the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member is a relative displacement amount in the predetermined axial direction from the reference position of the second member with respect to the first member. It will respond more reliably. Therefore, the relative displacement amount in the predetermined axial direction from the reference position of the second member relative to the first member can be detected more reliably and easily.

  In this case, the second conductive viscoelastic member is substantially the same material as the first conductive viscoelastic member, and is substantially the same as the first conductive viscoelastic member with respect to a plane perpendicular to the predetermined axial direction. It is preferable to have a plane-symmetric shape. That is, the first conductive viscoelastic member and the second conductive viscoelastic member are made of substantially the same material, and have substantially plane symmetry with the second member interposed therebetween. Accordingly, the first conductive viscoelastic member and the second conductive viscoelastic member can be made to have substantially the same impedance when deformed in substantially the same manner. Therefore, the relative displacement amount in the predetermined axial direction from the reference position of the second member relative to the first member can be detected more reliably and easily.

  Thereby, when the second member is largely displaced with respect to the first member, the deformation absorbing material is greatly deformed, and the deformation amount of the first conductive viscoelastic member and the second conductive viscoelastic member. Can be reduced. In particular, when the second member is displaced in a direction other than the predetermined axial direction with respect to the first member, it is possible to reduce the influence of the first conductive viscoelastic member and the second conductive viscoelastic member. . Then, by making the spring constant of the deformation absorbent smaller than the spring constant of the first conductive viscoelastic member and the second conductive viscoelastic member, the deformation of the deformation absorbent is changed to the first conductive viscoelastic member. The elastic member and the second conductive viscoelastic member can be hardly affected. Accordingly, it is possible to more reliably detect the relative displacement amount in the predetermined axial direction from the reference position of the second member with respect to the first member to be detected.

Further, in the displacement amount detection device of the present invention, the second member is disposed so as to be separated from the first member, and the second member rotates relative to the first member from the reference position and is orthogonal to the predetermined axis. When the second member is relatively displaceable in one or more of the three axes and the second member is displaced relative to the first member in the rotational direction around the predetermined axis from the reference position, the second member with respect to the first member The present invention can be applied to a displacement amount detection device that detects a relative displacement amount in a rotation direction around a predetermined axis from the reference position.

  In this case, with the following configuration, the second member is in a direction other than the rotation direction around the predetermined axis with respect to the first member (for example, the rotation direction and the axial direction around the axis other than the predetermined axis). Even when the relative displacement is performed, the relative displacement amount in the rotational direction around the predetermined axis from the reference position of the second member relative to the first member can be reliably detected. That is, it is possible to reliably extract only the relative rotation angle in the rotation direction around the predetermined axis from the reference position of the second member with respect to the first member.

Specifically, the displacement amount detection device of the present invention provides a reference for the second member relative to the first member when the second member is displaced relative to the first member in the rotational direction around the predetermined axis from the reference position. A displacement amount detecting device for detecting a relative displacement amount in a rotational direction from a position around a predetermined axis, wherein the first member and the second member are elastically connected, and the conductive viscoelasticity whose impedance changes according to deformation A first conductive viscoelastic member made of a material, which undergoes tensile deformation or compression deformation when the second member is displaced relative to the first member in the rotational direction around the predetermined axis from the reference position; The first member and the second member are elastically connected so as to be in parallel with the conductive viscoelastic member, and are made of a conductive viscoelastic material whose impedance changes in accordance with the deformation. The phase of the rotation direction of the member around the specified axis from the reference position A second conductive viscoelastic member that undergoes tensile and compressive deformation that is inversely symmetric with respect to the tensile and compressive deformation of the first conductive viscoelastic member when displaced, the first conductive viscoelastic member, and the second conductive material; One or more third conductive viscoelastic materials made of a conductive viscoelastic material that elastically connects the first member and the second member so as to be in parallel with the elastic viscoelastic member and whose impedance changes according to deformation. A first Wheatstone bridge circuit formed by the impedance of the elastic member, the first conductive viscoelastic member, and the second conductive viscoelastic member; the first conductive viscoelastic member; Formed by two selected conductive viscoelastic members other than the combination of the first conductive viscoelastic member and the second conductive viscoelastic member among the viscoelastic member and the third conductive viscoelastic member One or more second Wheatstone bridge circuits, and A power source for applying a bridge input voltage to the Wheatstone bridge circuit and the second Wheatstone bridge circuit, and a second power for the first member based on the bridge output voltage of the first Wheatstone bridge circuit and the second Wheatstone bridge circuit. A detection unit that detects a relative displacement amount in a rotation direction around a predetermined axis from a reference position of the member.
The total number of the first Wheatstone bridge circuit and the second Wheatstone bridge circuit is equal to or greater than a predetermined number obtained by adding 1 to the number of directions in which the second member can be displaced relative to the first member in the axial direction. Is set. For example, when the second member can be displaced relative to the first member in the three axial directions orthogonal to the rotational direction around the predetermined axis, for example, one first Wheatstone bridge circuit and three first members 2 Wheatstone bridge circuit.

  The detection unit further includes a reference voltage vector storage unit, an actual voltage vector detection unit, a contribution calculation unit, and a displacement calculation unit. The reference voltage vector storage unit stores in advance a reference voltage vector which is the predetermined number or more of bridge output voltages output in accordance with the relative displacement of the second member in the respective directions with respect to the first member. The actual voltage vector detection unit detects an actual voltage vector that is a bridge output voltage of the predetermined number or more that is output according to the relative displacement of the second member with respect to the actual first member. The contribution calculation unit calculates contributions related to the rotation direction around the predetermined axis and the components in the axial direction included in the actual voltage vector based on the reference voltage vector and the actual voltage vector. The displacement amount calculation unit is configured to determine the reference position of the second member relative to the first member based on the contribution related to the rotation direction component around the predetermined axis and the reference voltage vector related to the rotation direction around the predetermined axis stored in the reference voltage vector storage unit. To calculate the relative displacement amount in the rotation direction around the predetermined axis.

  In addition, when the detection unit detects the relative displacement amount in the rotation direction around the predetermined axis from the reference position of the second member with respect to the first member, the first conductive viscoelastic member and the second conductive viscoelasticity. It is preferable that the members have substantially the same impedance when subjected to substantially the same deformation. Thereby, the difference between the impedance of the first conductive viscoelastic member and the impedance of the second conductive viscoelastic member is a relative rotation in the rotational direction around the predetermined axis from the reference position of the second member relative to the first member. The angle will be handled more reliably. Accordingly, the relative rotation angle in the rotation direction around the predetermined axis from the reference position of the second member relative to the first member can be detected more reliably and easily.

  Here, in the displacement detection device of the present invention described above, the first conductive viscoelastic member and the second conductive viscoelastic member may each be composed of a plurality. For example, when the second member is relatively displaceable in the three orthogonal directions relative to the first member, three first conductive viscoelastic members and three second conductive viscoelastic members are provided. And each 1st electroconductive viscoelastic member and 2nd electroconductive viscoelastic member are each opposingly arranged in the orthogonal three-axis direction so that the 2nd member may be pinched | interposed. By doing so, the relative displacement amount in the orthogonal three-axis direction from the reference position of the second member relative to the first member is detected by each of the first conductive viscoelastic member and the second conductive viscoelastic member. Can do. In addition, for example, when the second member can be relatively displaced (relatively rotated) in the rotation direction around three orthogonal axes with respect to the first member, the first conductive viscoelastic member and the second conductive viscoelastic member. So that at least three are provided. And each 1st electroconductive viscoelastic member and 2nd electroconductive viscoelastic member are made to carry out an antisymmetric tension compression deformation in each case rotated relatively to the rotation direction of the orthogonal 3 axis | shafts. . By doing so, the relative rotation angle in the orthogonal three-axis direction from the reference position of the second member relative to the first member is detected by each of the first conductive viscoelastic member and the second conductive viscoelastic member. Can do.

  According to the displacement amount detection device of the present invention, it is possible to detect the relative displacement amount in the predetermined direction of the two members that are relatively displaced by using a viscoelastic member such as a rubber sensor having no anisotropy.

  Next, the present invention will be described in more detail with reference to embodiments.

(1) 1st Embodiment: Displacement amount detection apparatus which detects the relative displacement amount of an axial direction The displacement amount detection apparatus 30 of 1st Embodiment is the 2nd member 20 with respect to the 1st member 10, and a predetermined axis from a reference position. It is a device that detects the amount of relative displacement displaced in the direction. The configuration of the displacement amount detection device 30 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating a mechanical component of a displacement amount detection device 30 according to the first embodiment. 2 and 3 are diagrams illustrating the operation of the mechanical components of the displacement amount detection device 30 of the first embodiment. FIG. 4 is a diagram illustrating a circuit configuration portion of the displacement detection device 30 according to the first embodiment. Here, the displacement amount detection device 30 of the first embodiment is a device that detects a relative displacement amount in which the second member 20 is displaced in the vertical direction of FIG.

(1.1) Description of the 1st member 10 and the 2nd member 20 First, the 1st member 10 and the 2nd member 20 are demonstrated with reference to FIG. The first member 10 is a substantially rectangular frame. The first member 10 is, for example, a fixed frame fixed to another member (not shown). The second member 20 has a substantially rectangular parallelepiped shape, for example, and is disposed at the center of the frame shape of the first member 10. Here, the position where the second member 20 exists in the state of FIG. 1 with respect to the first member 10 is the reference position of the second member 20 with respect to the first member 10. In addition, the second member 20 can be relatively displaced in the frame of the first member 10 with respect to the first member 10 in the three axis directions perpendicular to the vertical direction, the horizontal direction, and the front-rear direction of FIG. Further, the second member 20 can be rotated by a slight angle with respect to the first member 10. That is, the second member 20 can be displaced from the reference position in the up-down direction, the left-right direction, the front-rear direction, and the rotation direction in FIG.

(1.2) Description of Mechanical Component Part of Displacement Detection Device 30 Next, a mechanical component part of the displacement detection device 30 of the first embodiment will be described with reference to FIGS. As shown in FIG. 1, the mechanical component of the displacement detection device 30 of the first embodiment includes a first conductive viscoelastic member 31, a second conductive viscoelastic member 32, a first electrode 33, It is composed of two electrodes 34, a third electrode 35, and a fourth electrode 36.

  The first conductive viscoelastic member 31 has a substantially cylindrical shape and is made of a conductive viscoelastic material. In the present embodiment, the conductive viscoelastic material is obtained by dispersing conductive particles such as metal powder in rubber or silicon. The length of the first conductive viscoelastic member 31 in the column direction (vertical direction in FIG. 1) is the length of the upper side portion in FIG. 1 of the first member 10 when the second member 20 is located at the reference position. The length is substantially equal to the distance between the inner side surface and the upper side surface of the second member 20 in FIG.

  A substantially disk-shaped first electrode 33 is fixed to the upper end surface of the first conductive viscoelastic member 31. And the 1st electrode 33 is being fixed to the center of the left-right direction of the inner surface of the upper side part of FIG. That is, the upper end surface of the first conductive viscoelastic member 31 is connected and fixed to the inner side surface of the upper side portion of FIG. 1 of the first member 10 via the first electrode 33. A substantially disk-shaped second electrode 34 is fixed to the lower end surface of the first conductive viscoelastic member 31. And the 2nd electrode 34 is being fixed to the center of the left-right direction of the upper surface of FIG. That is, the lower end surface of the first conductive viscoelastic member 31 is connected and fixed to the upper side surface of the second member 20 in FIG. Accordingly, when the second member 20 is located at the reference position, the first conductive viscoelastic member 31 extends from the first member 10 and the second member 20 so as to extend in the vertical direction of FIG. It is arranged between.

  The first conductive viscoelastic member 31 is deformed as the second member 20 is displaced from the reference position. That is, the first conductive viscoelastic member 31 is subjected to compression deformation or tensile deformation according to the displacement direction from the reference position of the second member 20. Here, the state of the first conductive viscoelastic member 31 when the second member 20 is located at the reference position is referred to as a reference state of the first conductive viscoelastic member 31.

  In addition, the resistance (or impedance) R1 (hereinafter referred to as “first resistance R1”) between the first electrode 33 and the second electrode 34 in the first conductive viscoelastic member 31 is the first conductive viscoelasticity member 31. It differs according to the deformation of the elastic member 31. Specifically, when the first conductive viscoelastic member 31 is compressed and deformed from the reference state, the first resistance R1 is reduced. This is because the conductive particles dispersed in the first conductive viscoelastic member 31 are close to each other. On the other hand, when the first conductive viscoelastic member 31 undergoes tensile deformation from the reference state, the first resistance R1 increases. This is because the space between the conductive particles dispersed in the first conductive viscoelastic member 31 is enlarged.

  The second conductive viscoelastic member 32 has a substantially cylindrical shape that is substantially the same shape as the first conductive viscoelastic member 31. Further, the second conductive viscoelastic member 32 is made of a conductive viscoelastic material that is substantially the same material as the first conductive viscoelastic member 31. The length of the second conductive viscoelastic member 32 in the column direction (vertical direction in FIG. 1) is the length of the lower side portion of the first member 10 in FIG. 1 when the second member 20 is located at the reference position. The length is approximately equal to the distance between the inner surface and the lower surface of the second member 20 in FIG.

  A substantially disk-shaped third electrode 35 is fixed to the lower end surface of the second conductive viscoelastic member 32. And the 3rd electrode 35 is being fixed to the center of the left-right direction of the inner surface of the lower side part of FIG. That is, the lower end surface of the second conductive viscoelastic member 32 is connected and fixed to the inner surface of the lower side portion of FIG. 1 of the first member 10 via the third electrode 35. A substantially disc-shaped fourth electrode 36 is fixed to the upper end surface of the second conductive viscoelastic member 32. And the 4th electrode 36 is being fixed to the horizontal center of the lower surface of FIG. That is, the upper end surface of the second conductive viscoelastic member 32 is connected and fixed to the lower surface of FIG. 1 of the second member 20 via the fourth electrode 36. Therefore, when the second member 20 is located at the reference position, the second conductive viscoelastic member 32 extends so as to extend in the vertical direction of FIG. It is arranged between.

  By arranging as described above, the second conductive viscoelastic member 32 is illustrated with respect to the first conductive viscoelastic member 31 such that the second member 20 is sandwiched by the first conductive viscoelastic member 31. 1 are arranged opposite to each other in the vertical direction. That is, the second member 20 is disposed between the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32, and the first conductive viscoelastic member 31, the second member 20, and the second The conductive viscoelastic member 32 is arranged on a straight line in the vertical direction of FIG. Furthermore, the second conductive viscoelastic member 32 is configured to be substantially plane-symmetric with the first conductive viscoelastic member 31 with respect to a plane perpendicular to the vertical direction in FIG.

  The second conductive viscoelastic member 32 is deformed as the second member 20 is displaced from the reference position. In other words, the second conductive viscoelastic member 32 is subjected to compressive deformation or tensile deformation according to the displacement direction from the reference position of the second member 20. Here, the state of the second conductive viscoelastic member 32 when the second member 20 is located at the reference position is referred to as a reference state of the second conductive viscoelastic member 32.

  In addition, the resistance (or impedance) R2 (hereinafter referred to as “second resistance R2”) between the third electrode 35 and the fourth electrode 36 in the second conductive viscoelastic member 32 is the second conductive viscoelasticity member 32. It differs depending on the deformation of the elastic member 32. Specifically, when the second conductive viscoelastic member 32 undergoes compression deformation from the reference state, the second resistance R2 becomes small. This is because the conductive particles dispersed in the second conductive viscoelastic member 32 are close to each other. On the other hand, when the second conductive viscoelastic member 32 undergoes tensile deformation from the reference state, the second resistance R2 increases. This is because the space between the conductive particles dispersed in the second conductive viscoelastic member 32 is enlarged.

  Here, as described above, the second conductive viscoelastic member 32 is made of substantially the same shape and material as the first conductive viscoelastic member 31. Accordingly, when the second member 20 is located at the reference position, the first resistance R1 of the first conductive viscoelastic member 31 and the second resistance R2 of the second conductive viscoelastic member 32 are substantially the same resistance. It becomes. Further, when the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 undergo substantially the same deformation, the first resistance R1 and the second resistance R2 have substantially the same resistance.

  The mechanical components of the displacement detection device 30 having such a configuration are as follows when the second member 20 is displaced. First, the case where the second member 20 is displaced from the reference position in the vertical direction of FIG. 1 will be described with reference to FIG. As shown in FIG. 2, when the second member 20 is displaced upward in FIG. 1, the first conductive viscoelastic member 31 undergoes compressive deformation, and the second conductive viscoelastic member 32 undergoes tensile deformation. . In this case, the first resistor R1 is reduced, while the second resistor R2 is increased. Furthermore, as the amount of displacement of the second member 20 from the reference position to the upper side in FIG. 1 increases, the first resistance R1 further decreases and the second resistance R2 increases further.

  On the other hand, when the second member 20 is displaced downward in FIG. 1, the first conductive viscoelastic member 31 undergoes tensile deformation, and the second conductive viscoelastic member 32 undergoes compressive deformation. In this case, the first resistor R1 is increased while the second resistor R2 is decreased. Furthermore, as the amount of displacement of the second member 20 from the reference position to the lower side in FIG. 1 increases, the first resistance R1 further increases and the second resistance R2 decreases further.

  That is, when the second member 20 is displaced in the vertical direction in FIG. 1, the second conductive viscoelastic member 32 undergoes a tensile compression deformation that is opposite to the tensile compression deformation of the first conductive viscoelastic member 31. To do. And the 1st resistance R1 and the 2nd resistance R2 become larger or smaller, so that the amount of displacement of the 2nd member 20 in the up-and-down direction of Drawing 1 is large. Accordingly, the larger the amount of displacement of the second member 20 in the vertical direction in FIG. 1 from the reference position, the greater the difference between the first resistance R1 and the second resistance R2.

  Next, the case where the second member 20 is displaced in the left-right direction in FIG. 1 will be described with reference to FIG. As shown in FIG. 3, when the second member 20 is displaced to the left in FIG. 1, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 both undergo tensile deformation. Specifically, in this case, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are plane-symmetric with respect to a plane perpendicular to the vertical direction in FIG. 1 before and after the deformation. Maintain shape. That is, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are subjected to the same tensile deformation. At this time, both the first resistance R1 and the second resistance R2 become small. The first resistor R1 and the second resistor R2 are the same resistor.

  When the second member 20 is displaced to the right side of FIG. 1, the first conductive viscoelastic member 31 and the second conductive viscosity are also the same as when the second member 20 is displaced to the left side of FIG. Both elastic members 32 undergo tensile deformation. Accordingly, the first resistor R1 and the second resistor R2 in this case are both small and have the same resistance.

  Further, when the second member 20 is displaced in the front-rear direction of FIG. 1, the first conductive viscoelastic member 31 and the second conductive member are displaced in the same manner as when the second member 20 is displaced in the left-right direction of FIG. Both the viscoelastic members 32 undergo tensile deformation. Accordingly, the first resistor R1 and the second resistor R2 in this case are both small and have the same resistance.

  Further, when the second member 20 is rotationally displaced in the clockwise direction of FIG. When the second member 20 is rotationally displaced in the clockwise direction in FIG. 1, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 both undergo tensile deformation. Specifically, in this case, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are deformed into a point-symmetric shape around the rotation axis. That is, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are subjected to the same tensile deformation. At this time, both the first resistor R1 and the second resistor R2 become smaller and have the same resistance.

  Further, when the second member 20 is rotationally displaced in the counterclockwise direction of FIG. 1, when it is rotated about the left-right axis of FIG. 1, or when it is rotationally displaced about the vertical axis of FIG. The first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are both subjected to tensile deformation as in the case where 20 is rotationally displaced clockwise in FIG. Accordingly, the first resistor R1 and the second resistor R2 in this case are both small and have the same resistance.

(1.3) Description of Circuit Configuration Portion of Displacement Detection Device 30 Next, a circuit configuration portion of the displacement detection device 30 of the first embodiment will be described with reference to FIG. As shown in FIG. 4, the circuit components of the displacement detection device 30 of the first embodiment include a Wheatstone bridge circuit 41, a DC power supply 42, a bridge output voltage detection unit 43, and a displacement detection unit 44. Consists of

  The Wheatstone bridge circuit 41 includes a first half bridge circuit 411 and a second half bridge circuit 412. The first half bridge circuit 411 connects the first resistor R1 of the first conductive viscoelastic member 31 and the third resistor R3 in series. Specifically, the second electrode 34 and one end side of the third resistor R3 are electrically connected directly. The second half bridge circuit 412 connects the second resistor R2 of the second conductive viscoelastic member 32 and the fourth resistor R4 in series. Specifically, the fourth electrode 36 and one end side of the fourth resistor R4 are electrically connected directly. Here, the same resistance is used for the third resistor R3 and the fourth resistor R4. Further, the third resistor R3 and the fourth resistor R4 are much larger than the first resistor R1 and the second resistor R2.

  The first half bridge circuit 411 and the second half bridge circuit 412 are connected in parallel. Specifically, one end side of the first conductive viscoelastic member 31 and one end side of the second conductive viscoelastic member 32 are directly connected. More specifically, the first electrode 33 and the third electrode 35 are directly connected, and the other end side of the third resistor R3 and the other end side of the fourth resistor R4 are directly connected.

  Further, the midpoint of the first half bridge circuit 411 and the midpoint of the second half bridge circuit 412 are connected. Specifically, the electrical connection between the other end of the first conductive viscoelastic member 31 and the third resistor R3 is electrically between the other end of the second conductive viscoelastic member 32 and the fourth resistor R4. It is connected to the. More specifically, the second electrode 34 and the fourth electrode 36 are electrically connected.

  The DC power source 42 applies a bridge input voltage V <b> 1 to the Wheatstone bridge circuit 41. Specifically, the DC power source 42 applies a bridge input voltage V <b> 1 to each end of the Wheatstone bridge circuit 41. More specifically, the positive electrode side of the DC power supply 42 is connected to the first electrode 33 and the third electrode 35. Further, the negative electrode side of the DC power source 42 is connected to the other end side of the third resistor R3 and the other end side of the fourth resistor R4.

  The bridge output voltage detector 43 detects the bridge output voltage V <b> 2 of the Wheatstone bridge circuit 41. The bridge output voltage V <b> 2 is a voltage at a portion connecting the intermediate point of the first half bridge circuit 411 and the intermediate point of the second half bridge circuit 412. That is, the bridge output voltage V <b> 2 is a voltage difference between the intermediate points of the first half bridge circuit 411 and the second half bridge circuit 412. Here, the bridge output voltage V <b> 2 is a voltage obtained by subtracting the voltage at the midpoint of the second half bridge circuit 412 from the voltage at the midpoint of the first half bridge circuit 411.

  The displacement detection unit 44 (detection unit in the present invention) receives the bridge output voltage V2 detected by the bridge output voltage detection unit 43. And the displacement amount detection part 44 calculates | requires the displacement amount to the up-down direction of FIG. 1 by the 2nd member 20 based on the input bridge | bridging output voltage V2.

  Hereinafter, a method in which the displacement amount detection unit 44 obtains the displacement amount of the second member 20 from the reference position in the vertical direction in FIG. 1 based on the bridge output voltage V2 will be specifically described.

  First, the bridge output voltage V2 can be expressed as Equation 1.

  Here, since the first resistor R1 (0) and the second resistor R2 (0) are equal when the second member 20 is located at the reference position, the bridge output voltage V2 becomes zero. In other words, it can be expressed as in Equation 2.

  When the second member 20 is displaced from the reference position, the first resistance R1 and the second resistance R2 change according to the displacement of the second member 20 as described above. Here, when the second member 20 performs displacement from the reference position in the vertical direction in FIG. 1, displacement in the horizontal direction in FIG. 1, displacement in the front-rear direction in FIG. 1, and displacement in the rotation direction, respectively. The first resistor R1 and the second resistor R2 have a region having linearity with respect to each displacement. The region where the first resistor R1 and the second resistor R2 have linearity is, for example, a region where the strain of the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 is 10% or less. Within this region, the change ΔR1 in the first resistance R1 and the change ΔR2 in the second resistance R2 due to the displacement of the second member 20 can be expressed as in Equation 3.

  Here, as described above, when the second member 20 is displaced in the left-right direction, the front-rear direction, and the rotation direction in FIG. 1, the first resistance R1 and the second resistance R2 have the same resistance. That is, these relationships can be expressed as in Equation 4.

  Furthermore, as described above, the third resistor R3 and the fourth resistor R4 are much larger than the first resistor R1 and the second resistor R2. That is, the relationship shown in Equation 5 is obtained. Therefore, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 have a relationship as shown in Equation 6.

  From the above, when Equations 1 to 6 are put together, the bridge output voltage V2 can be expressed as Equation 7.

  As described above, the bridge output voltage V2 is expressed as a difference between the change ΔR11 of the first resistor R1 and the change ΔR21 of the second resistor R2 due to the second member 20 being displaced from the reference position only in the vertical direction of FIG. The That is, the bridge output voltage V2 is not affected by the displacement of the second member 20 from the reference position in the left-right direction, the front-rear direction, and the rotation direction in FIG. Therefore, even when the second member 20 is displaced in various directions from the reference position, the bridge output voltage V2 extracts only the influence due to the displacement of the second member 20 from the reference position in the vertical direction in FIG. it can.

  When the second member 20 is displaced from the reference position to the upper side in FIG. 1, the first resistance R1 is reduced and the second resistance R2 is increased. That is, the value obtained by subtracting the change ΔR21 of the second resistor R2 from the change ΔR11 of the first resistor R1 is a negative value. Furthermore, as the amount of displacement of the second member 20 from the reference position to the upper side in FIG. 1 increases, the difference between the change ΔR11 of the first resistance R1 and the change ΔR21 of the second resistance R2 increases.

  Further, when the second member 20 is displaced from the reference position to the lower side in FIG. 1, the first resistance R1 increases and the second resistance R2 decreases. That is, a value obtained by subtracting the change ΔR21 of the second resistor R2 from the change ΔR11 of the first resistor R1 is a positive value. Furthermore, the difference between the change ΔR11 of the first resistance R1 and the change ΔR21 of the second resistance R2 increases as the displacement of the second member 20 from the reference position to the lower side in FIG. 1 increases.

  That is, the bridge output voltage V2 corresponds to the amount of displacement of the second member 20 from the reference position in the vertical direction in FIG. Therefore, by converting the unit system of the bridge output voltage V2, the amount of displacement of the second member 20 in the vertical direction in FIG. 1 from the reference position can be obtained.

  If the relative displacement amount in the predetermined axis direction from the reference position of the second member 20 with respect to the first member 10 can be obtained, the relative displacement amount can be used to calculate acceleration, load, and the like.

(2) Modifications of the First Embodiment (2.1) In the above embodiment, the first resistor R1 and the second resistor R2 have been described on the assumption that they are in a region having linearity. However, when the displacement amount of the second member 20 with respect to the first member 10 is large, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are greatly deformed, and the first resistance R1 and the second resistance. R2 may be a region that does not have linearity. In such a case, the displacement amount detection device 50 may be configured as shown in FIG. 5, for example. As shown in FIG. 5, the displacement amount detection device 50 further includes a deformation absorbing material 51. That is, the first electrode 33 fixed to the upper end surface of the first conductive viscoelastic member 31 is connected and fixed to the first member 10 via the deformation absorbing material 51. Further, the third electrode 35 fixed to the lower end surface of the second conductive viscoelastic member 32 is connected and fixed to the first member 10 via the deformation absorbing material 51.

  Thereby, when the 2nd member 20 is displaced largely with respect to the 1st member 10, the deformation | transformation absorber 51 deform | transforms largely and the 1st electroconductive viscoelastic member 31 and the 2nd electroconductive viscoelastic member 32 are obtained. The amount of deformation of can be reduced. Therefore, the deformation amount of the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 can be defined so that the first resistance R1 and the second resistance R2 are regions having linearity. At this time, the relationship between the spring constant K2 of the deformation absorbing material 51 and the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 spring constant K1 may be set to, for example, Equation 8.

  With such a relationship, the deformation of the deformation absorbing material 51 can hardly affect the deformation of the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32. Furthermore, the influence of deformation of the second member 20 in the embodiment other than the vertical direction in FIG. 1 can be reduced. Thereby, the displacement amount of the 2nd member 20 to the direction which is a candidate for detection can be detected more certainly.

  In FIG. 5, the deformation absorbing material 51 is disposed between the first conductive viscoelastic member 31 and the first member 10 and between the second conductive viscoelastic member 32 and the first member 10. However, it is not limited to this. For example, it may be disposed between the first conductive viscoelastic member 31 and the second member 20 and between the second conductive viscoelastic member 32 and the second member 20.

(2.2) Displacement amount detection device for detecting relative displacement amount in three orthogonal axes In the above embodiment, the second member 20 is moved in a predetermined one-axis direction (vertical direction in FIG. 1) with respect to the first member 10. The displacement amount detection device 30 that detects the relative displacement amount has been described. FIG. 6 and FIG. 7 show a displacement amount detection device 60 that can detect the relative displacement amounts of the second member 20 in the orthogonal three-axis directions with respect to the first member 10 by applying the displacement amount detection device 30. The description will be given with reference. FIG. 6 is a diagram showing a mechanical component of the displacement amount detection device 60. FIG. 7 is a diagram illustrating a circuit configuration portion of the displacement detection device 60.

  As shown in FIG. 6, the 1st member 10 (not shown in FIG. 6) has comprised the substantially rectangular parallelepiped box-shaped frame fixed to the other member. The second member 20 has a disk shape and is disposed inside the first member 10.

  And the displacement amount detection apparatus 60 arrange | positions the displacement amount detection apparatus 30 mentioned above to a X-axis direction, a Y-axis direction, and a Z-axis direction. That is, the displacement amount detection device 60 includes an X-axis direction displacement amount detection unit 61, a Y-axis direction displacement amount detection unit 62, and a Z-axis direction displacement amount detection unit 63. The X-axis direction displacement detection unit 61 includes an X-axis first conductive viscoelastic member 31a, an X-axis second conductive viscoelastic member 32a, an X-axis first electrode 33a, and an X-axis second electrode. The electrode 34a, the X-axis third electrode 35a, and the X-axis fourth electrode 36a are configured. The Y-axis direction displacement detection unit 62 includes a Y-axis first conductive viscoelastic member 31b, a Y-axis second conductive viscoelastic member 32b, a Y-axis first electrode 33b, and a Y-axis second electrode. The electrode 34b, the Y-axis third electrode 35b, and the Y-axis fourth electrode 36b are configured. The Z-axis direction displacement detection unit 63 includes a Z-axis first conductive viscoelastic member 31c, a Z-axis second conductive viscoelastic member 32c, a Z-axis first electrode 33c, and a Z-axis second electrode. The electrode 34c, the Z-axis third electrode 35c, and the Z-axis fourth electrode 36c are configured.

  Here, the structure which attached | subjected the said code | symbol 31a-36a, 31b-36b, 31c-36c consists of a structure substantially the same as the structure which attached | subjected the codes | symbols 31-36 in the said 1st Embodiment. However, in the configuration in which the alphabet a is added in the reference numerals, the vertical direction in FIG. 1 in the first embodiment is the X-axis direction in FIG. In the configuration in which alphabets b are added to the reference numerals, the vertical direction in FIG. 1 in the first embodiment is the Y-axis direction in FIG. In the configuration in which the letter c is added in the reference numerals, the vertical direction in FIG. 1 in the first embodiment is the Z-axis direction in FIG.

  As shown in FIG. 7, the circuit components of the displacement detector 60 include an X-axis Wheatstone bridge circuit 41a, a Y-axis Wheatstone bridge circuit 41b, and a Z-axis Wheatstone bridge circuit 41c. , DC power source 42, X-axis bridge output voltage detector 43a, Y-axis bridge output voltage detector 43b, Z-axis bridge output voltage detector 43c, X-axis displacement detector 44a, Y The shaft displacement amount detection unit 44b and the Z-axis displacement amount detection unit 44c are configured.

  The X-axis Wheatstone bridge circuit 41a uses the first resistance R1 of the first conductive viscoelastic member 31 of the Wheatstone bridge circuit 41 of the first embodiment as the X-axis first conductive viscoelastic member 31a. The first resistance R1 is used, and the second resistance R2 of the second conductive viscoelastic member 32 is the second resistance R2 of the second conductive viscoelastic member 32a for X-axis. The Y-axis Wheatstone bridge circuit 41b uses the first resistance R1 of the first conductive viscoelastic member 31 of the Wheatstone bridge circuit 41 of the first embodiment as the Y-axis first conductive viscoelastic member 31b. The first resistance R1 is used, and the second resistance R2 of the second conductive viscoelastic member 32 is the second resistance R2 of the second conductive viscoelastic member 32b for Y-axis. The Z-axis Wheatstone bridge circuit 41c uses the first resistance R1 of the first conductive viscoelastic member 31 of the Wheatstone bridge circuit 41 of the first embodiment as the Z-axis first conductive viscoelastic member 31c. The first resistor R1 is used, and the second resistor R2 of the second conductive viscoelastic member 32 is the second resistor R2 of the second conductive viscoelastic member 32c for X-axis.

  The X-axis bridge output voltage detector 43a detects the bridge output voltage V2 of the X-axis Wheatstone bridge circuit 41a. The Y-axis bridge output voltage detector 43b detects the bridge output voltage V2 of the Y-axis Wheatstone bridge circuit 41b. The Z-axis bridge output voltage detector 43c detects the bridge output voltage V2 of the Z-axis Wheatstone bridge circuit 41c.

  Then, the X-axis displacement amount detection unit 44a obtains the displacement amount of the second member 20 in the X-axis direction based on the bridge output voltage V2 of the X-axis Wheatstone bridge circuit 41a. The Y-axis displacement amount detection unit 44b obtains the displacement amount of the second member 20 in the Y-axis direction based on the bridge output voltage V2 of the Y-axis Wheatstone bridge circuit 41b. The Z-axis displacement detector 44c obtains the displacement of the second member 20 in the Z-axis direction based on the bridge output voltage V2 of the Z-axis Wheatstone bridge circuit 41c. In addition, this displacement amount detection apparatus 60 can be utilized as an acceleration sensor or a load sensor in three orthogonal axes.

  (2.3) In the above embodiment, the DC power supply 42 is provided in the circuit configuration portion of the displacement detection device 30, but it may be an AC power supply. In this case, the resistors R1 to R4 described above are replaced with impedances.

(3) Second Embodiment: Displacement Amount Detection Device for Detecting Relative Displacement Amount (Relative Rotation Angle) Next, a displacement amount detection device 70 according to a second embodiment will be described with reference to FIGS. 8 and 9. explain. The displacement amount detection device 70 according to the second embodiment is a device that detects a relative displacement amount (relative rotation angle) in which the second member 20 is rotationally displaced about a predetermined axis from the reference position with respect to the first member 10. In addition, FIG. 8 is a figure which shows the mechanical structure part of the displacement amount detection apparatus 70 of 2nd Embodiment. FIG. 9 is a diagram illustrating a circuit configuration portion of the displacement amount detection device 70 of the second embodiment.

(3.1) Description of the 1st member 10 and the 2nd member 20 The 1st member 10 and the 2nd member 20 are demonstrated with reference to FIG. The first member 10 has a substantially cylindrical shape. The first member 10 is fixed to, for example, another member (not shown). The second member 20 has a substantially cylindrical shape with a smaller diameter than the first member 10. The second member 20 is disposed substantially coaxially in the center of the first member 10. Here, the second member 20 is rotatable around the front-rear direction axis in FIG. 8 by a slight angle with respect to the first member 10 inside the first member 10. Further, the second member 20 can be displaced relative to the first member 10 in the front-rear direction of FIG. Here, the second member 20 will be described assuming that it cannot be displaced relative to the first member 10 in the vertical direction and the horizontal direction in FIG. That is, the second member 20 can be displaced with respect to the first member 10 in the rotational displacement around the front-rear axis in FIG. 8 and in the front-rear axis direction in FIG.

(3.2) Description of Mechanical Component Part of Displacement Detection Device 70 Next, a mechanical component part of the displacement detection device 70 of the second embodiment will be described with reference to FIG. The conductive viscoelastic member 71, the first electrode 72, the second electrode 73, the third electrode 74, the fourth electrode 75, the fifth electrode 76, and the sixth electrode 77 are configured.

  The conductive viscoelastic member 71 is filled in a space surrounded by the first member 10 and the second member 20. That is, the conductive viscoelastic member 71 is connected and fixed to all the inner peripheral surfaces of the first member 10 and all the outer peripheral surfaces of the second member 20. The conductive viscoelastic member 71 is made of a conductive viscoelastic member. In the present embodiment, the conductive viscoelastic member is obtained by dispersing conductive particles such as metal powder in rubber or silicon.

  The first electrode 72 is an electrode fixed to the inner peripheral surface of the first member 10. In FIG. 8, the first electrode 72 is an electrode disposed on the upper left side on the inner peripheral surface of the first member 10. The second electrode 73 is an electrode fixed to the inner peripheral surface of the first member 10. In FIG. 8, the second electrode 73 is an electrode disposed on the upper right side on the inner peripheral surface of the first member 10. The third electrode 74 is an electrode fixed to the outer peripheral surface of the second member 20. In FIG. 8, the third electrode 74 is an electrode that is disposed on the upper outer peripheral surface of the second member 20. The fourth electrode 75 is an electrode fixed to the inner peripheral surface of the first member 10. The fourth electrode 75 is an electrode disposed on the lower left side on the inner peripheral surface of the first member 10 in FIG. The fifth electrode 76 is an electrode fixed to the inner peripheral surface of the first member 10. The fifth electrode 76 is an electrode disposed on the lower right side on the inner peripheral surface of the first member 10 in FIG. The sixth electrode 77 is an electrode fixed to the outer peripheral surface of the second member 20. In FIG. 8, the sixth electrode 77 is an electrode disposed on the lower side of the outer peripheral surface of the second member 20.

  Here, the first electrode 72 and the third electrode 74 are obtained when a part of the conductive viscoelastic member 71 existing on a line segment connecting the first electrode 72 and the third electrode 74 is regarded as a resistance. Both end electrodes are formed. Therefore, in FIG. 8, a part of the conductive viscoelastic member 71 existing on the line segment connecting the first electrode 72 and the third electrode 74 is referred to as a sixth resistor R6. Further, the second electrode 73 and the third electrode 74 are both ends of a portion of the conductive viscoelastic member 71 existing on the line segment connecting the second electrode 73 and the third electrode 74 as a resistance. It is an electrode. Therefore, in FIG. 8, a part of the conductive viscoelastic member 71 existing on a line segment connecting the second electrode 73 and the third electrode 74 is referred to as a seventh resistor R7. The fourth electrode 75 and the sixth electrode 77 have both ends when a part of the conductive viscoelastic member 71 existing on the line connecting the fourth electrode 75 and the sixth electrode 77 is regarded as a resistance. It is an electrode. Therefore, in FIG. 8, a part of the conductive viscoelastic member 71 existing on the line segment connecting the fourth electrode 75 and the sixth electrode 77 is referred to as an eighth resistor R8. Further, the fifth electrode 76 and the sixth electrode 77 have both ends when a part of the conductive viscoelastic member 71 existing on the line connecting the fifth electrode 76 and the sixth electrode 77 is regarded as a resistance. It is an electrode. Therefore, in FIG. 8, a part of the conductive viscoelastic member 71 existing on the line segment connecting the fifth electrode 76 and the sixth electrode 77 is referred to as a ninth resistor R9.

  In the mechanical component of the displacement detection device 70 having such a configuration, the first electrode 72 and the third electrode 74 when the second member 20 rotates in the clockwise direction in FIG. The separation distance from is increased. That is, it is considered that the conductive viscoelastic member 71 existing between the first electrode 72 and the third electrode 74 has undergone tensile deformation. Further, the separation distance between the second electrode 73 and the third electrode 74 is reduced. That is, it is considered that the conductive viscoelastic member 71 existing between the second electrode 73 and the third electrode 74 has undergone compression deformation. Accordingly, the sixth resistor R6 increases, whereas the seventh resistor R7 decreases.

  Further, the separation distance between the fourth electrode 75 and the sixth electrode 77 becomes small. That is, it is considered that the conductive viscoelastic member 71 existing between the fourth electrode 75 and the sixth electrode 77 has undergone compression deformation. Further, the separation distance between the fifth electrode 76 and the sixth electrode 77 is increased. In other words, it is considered that the conductive viscoelastic member 71 existing between the fifth electrode 76 and the sixth electrode 77 has undergone tensile deformation. Accordingly, the eighth resistor R8 is reduced, while the ninth resistor R9 is increased.

  On the other hand, when the second member 20 rotates counterclockwise in FIG. 8 with respect to the first member 10, the separation distance between the first electrode 72 and the third electrode 74 becomes small. That is, it is considered that the conductive viscoelastic member 71 existing between the first electrode 72 and the third electrode 74 has undergone compression deformation. Further, the separation distance between the second electrode 73 and the third electrode 74 is increased. In other words, it is considered that the conductive viscoelastic member 71 existing between the second electrode 73 and the third electrode 74 has undergone tensile deformation. Accordingly, the sixth resistor R6 is reduced, while the seventh resistor R7 is increased.

  Further, the separation distance between the fourth electrode 75 and the sixth electrode 77 is increased. That is, it is considered that the conductive viscoelastic member 71 existing between the fourth electrode 75 and the sixth electrode 77 has undergone tensile deformation. Further, the separation distance between the fifth electrode 76 and the sixth electrode 77 is reduced. That is, it is considered that the conductive viscoelastic member 71 existing between the fifth electrode 76 and the sixth electrode 77 has undergone compression deformation. Accordingly, the eighth resistor R8 increases, whereas the ninth resistor R9 decreases.

  That is, when the second member 20 is rotationally displaced in the direction around the longitudinal axis in FIG. 8, the conductive viscoelastic member 71 existing between the first electrode 72 and the third electrode 74, and the second electrode 73 The conductive viscoelastic member 71 existing between the third electrode 74 undergoes tensile and compressive deformations that are inversely symmetrical with each other. When the second member 20 is rotationally displaced in the direction about the front-rear axis in FIG. 8, the conductive viscoelastic member 71 existing between the fourth electrode 75 and the sixth electrode 77, the fifth electrode 76, The conductive viscoelastic member 71 existing between the sixth electrode 77 undergoes tensile and compressive deformations that are inversely symmetric to each other.

  And the 6th resistance R6 and 7th resistance R7 become larger or smaller, so that the amount of rotation displacement of the 2nd member 20 around the direction axis of Drawing 8 is large. Therefore, the difference between the sixth resistance R6 and the seventh resistance R7 increases as the rotational displacement amount of the second member 20 around the longitudinal axis in FIG. 8 increases. Further, as the rotational displacement amount of the second member 20 around the front-rear axis in FIG. 8 is larger, the eighth resistance R8 and the ninth resistance R9 are larger or smaller. Therefore, the difference between the eighth resistance R8 and the ninth resistance R9 increases as the rotational displacement amount of the second member 20 about the longitudinal axis in FIG. 8 increases.

  Next, a case where the second member 20 is displaced in the front-rear direction of FIG. 8 with respect to the first member 10 will be described. In this case, the separation distance between the first electrode 72 and the third electrode 74 and the separation distance between the second electrode 73 and the third electrode 74 are both increased by the same amount. That is, both the conductive viscoelastic member 71 present between the first electrode 72 and the third electrode 74 and the conductive viscoelastic member 71 present between the second electrode 73 and the third electrode 74 are The same tensile deformation is considered. Therefore, both the sixth resistor R6 and the seventh resistor R7 are increased. The sixth resistor R6 and the seventh resistor R7 are the same resistor. In this case, the eighth resistor R8 and the ninth resistor have the same relationship as the sixth resistor R6 and the seventh resistor R7.

(3.3) Description of Circuit Configuration Part of Displacement Detection Device 70 Next, a circuit configuration part of the displacement detection device 70 of the second embodiment will be described with reference to FIG. As shown in FIG. 9, the circuit components of the displacement detection device 70 of the second embodiment include a first Wheatstone bridge circuit 81, a second Wheatstone bridge circuit 82, a DC power supply 83, a first The bridge output voltage detection unit 84, the second bridge output voltage detection unit 85, and the displacement amount detection unit 86 are configured.

  The first Wheatstone bridge circuit 81 includes a first half bridge circuit 811 and a second half bridge circuit 812. The first half bridge circuit 811 has a sixth resistor R6 and a third resistor R3 connected in series. Specifically, the first electrode 72 and one end side of the third resistor R3 are electrically connected directly. The second half bridge circuit 812 has a seventh resistor R7 and a fourth resistor R4 connected in series. Specifically, the second electrode 73 and one end of the fourth resistor R4 are electrically connected directly. Here, the same resistance is used for the third resistor R3 and the fourth resistor R4. Further, the third resistor R3 and the fourth resistor R4 are much larger than the sixth resistor R6 and the seventh resistor R7. The first half bridge circuit 811 and the second half bridge circuit 812 are connected in parallel. Specifically, the third electrode 74 is shared, and the other end side of the third resistor R3 and the other end side of the fourth resistor R4 are directly connected. Further, the midpoint of the first half bridge circuit 811 and the midpoint of the second half bridge circuit 812 are connected. Specifically, the first electrode 72 and the second electrode 73 are electrically connected.

  The second Wheatstone bridge circuit 82 includes a first half bridge circuit 821 and a second half bridge circuit 822. The first half bridge circuit 821 has an eighth resistor R8 and a third resistor R3 connected in series. Specifically, the fourth electrode 75 and one end side of the third resistor R3 are electrically connected directly. The second half bridge circuit 822 connects a ninth resistor R9 and a fourth resistor R4 in series. Specifically, the fifth electrode 76 and one end side of the fourth resistor R4 are electrically connected directly. Here, the third resistor R3 and the fourth resistor R4 use the same resistor as described above. Further, the third resistor R3 and the fourth resistor R4 are much larger than the eighth resistor R8 and the ninth resistor R9. The first half bridge circuit 821 and the second half bridge circuit 822 are connected in parallel. Specifically, the sixth electrode 77 is shared, and the other end side of the third resistor R3 and the other end side of the fourth resistor R4 are directly connected. Further, the midpoint of the first half-bridge circuit 821 and the midpoint of the second half-bridge circuit 822 are connected. Specifically, the fourth electrode 75 and the fifth electrode 76 are electrically connected.

  The DC power supply 83 applies a bridge input voltage V <b> 1 to the first Wheatstone bridge circuit 81 and the second Wheatstone bridge circuit 82. Specifically, the DC power supply 83 applies a bridge input voltage V <b> 1 to both ends of the first Wheatstone bridge circuit 81 and the second Wheatstone bridge circuit 82. More specifically, the positive electrode side of the DC power supply 83 is connected to the third electrode 74 and the sixth electrode 77. Further, the negative electrode side of the DC power supply 83 is connected to the other end side of the third resistor R3 and the other end side of the fourth resistor R4 of the first Wheatstone bridge circuit 81 and the second Wheatstone bridge circuit 82, respectively. Yes.

  The first bridge output voltage detector 84 detects the bridge output voltage V 21 of the first Wheatstone bridge circuit 81. The bridge output voltage V21 is a voltage at a portion connecting the intermediate point of the first half bridge circuit 811 and the intermediate point of the second half bridge circuit 812. That is, the bridge output voltage V <b> 21 is a voltage difference between the intermediate points of the first half bridge circuit 811 and the second half bridge circuit 812. Here, the bridge output voltage V21 is a voltage obtained by subtracting the voltage at the midpoint of the second half bridge circuit 812 from the voltage at the midpoint of the first half bridge circuit 811.

  The second bridge output voltage detector 85 detects the bridge output voltage V22 of the second Wheatstone bridge circuit 82. The bridge output voltage V22 is a voltage at a portion connecting the intermediate point of the first half bridge circuit 821 and the intermediate point of the second half bridge circuit 822. That is, the bridge output voltage V <b> 22 is a voltage difference between the intermediate points of the first half bridge circuit 821 and the second half bridge circuit 822. Here, the bridge output voltage V22 is a voltage obtained by subtracting the intermediate point voltage of the second half bridge circuit 822 from the intermediate point voltage of the first half bridge circuit 821.

  The displacement detector 86 (detector in the present invention) receives the bridge output voltage V21 detected by the first bridge output voltage detector 84 and the bridge output voltage V22 detected by the second bridge output voltage detector 85. . Then, the displacement amount detector 86 detects the amount of displacement (rotation angle) of the second member 20 from the reference position in the rotation direction around the front-rear axis in FIG. 8 based on either or both of the input bridge output voltages V21 and V22. ) Note that the amount of displacement can be obtained by the same method as in the first embodiment described above.

(4) Modification of Second Embodiment In the second embodiment, the second member 20 can only be rotationally displaced about the front-rear axis in FIG. On the other hand, the deformation mode is intended for a case where the second member 20 is displaced in the three orthogonal axes with respect to the first member 10 and is rotationally displaced about a predetermined axis. The displacement amount detection device 90 according to the modification is configured to detect a relative displacement amount (relative rotation angle) in which the second member 20 is rotationally displaced about the predetermined axis with respect to the first member 10.

  A displacement amount detection device 90 according to a modification of the second embodiment will be described with reference to FIG. FIG. 10 is a diagram illustrating a circuit configuration portion of the displacement amount detection device 90 according to a modification of the second embodiment. Since the mechanical component of the displacement detection device 90 is the same as that of the displacement detection device 70 of the second embodiment described above, description thereof is omitted.

  As shown in FIG. 10, the circuit configuration portion of the displacement amount detection device 90 includes a Wheatstone bridge circuit portion 91, a DC power source 92, a bridge output voltage detection portion 93, and a displacement amount detection portion 94. .

  The Wheatstone bridge circuit section 91 is formed by four Wheatstone bridge circuits 91a to 91d. The first Wheatstone bridge circuit 91a includes a first half bridge circuit 911a and a second half bridge circuit 912a. The first half bridge circuit 911a connects the sixth resistor R6 and the third resistor R3 in series. The second half bridge circuit 912a has a seventh resistor R7 and a fourth resistor R4 connected in series. The first half bridge circuit 911a and the second half bridge circuit 912a are connected in parallel. Further, the midpoint of the first half-bridge circuit 911a and the midpoint of the second half-bridge circuit 912a are connected.

  The second Wheatstone bridge circuit 91b includes a first half bridge circuit 911b and a second half bridge circuit 912b. The first half bridge circuit 911b connects a seventh resistor R7 and a third resistor R3 in series. The second half bridge circuit 912b connects an eighth resistor R8 and a fourth resistor R4 in series. The first half bridge circuit 911b and the second half bridge circuit 912b are connected in parallel. Further, the midpoint of the first half-bridge circuit 911b and the midpoint of the second half-bridge circuit 912b are connected.

  The third Wheatstone bridge circuit 91c includes a first half bridge circuit 911c and a second half bridge circuit 912c. The first half bridge circuit 911c connects an eighth resistor R8 and a third resistor R3 in series. The second half bridge circuit 912c connects a ninth resistor R9 and a fourth resistor R4 in series. The first half bridge circuit 911c and the second half bridge circuit 912c are connected in parallel. Furthermore, the midpoint of the first half bridge circuit 911c and the midpoint of the second half bridge circuit 912c are connected.

  The fourth Wheatstone bridge circuit 91d includes a first half bridge circuit 911d and a second half bridge circuit 912d. The first half bridge circuit 911d connects a ninth resistor R9 and a third resistor R3 in series. The second half bridge circuit 912d has a sixth resistor R6 and a fourth resistor R4 connected in series. The first half bridge circuit 911d and the second half bridge circuit 912d are connected in parallel. Further, the midpoint of the first half-bridge circuit 911d and the midpoint of the second half-bridge circuit 912d are connected.

  The DC power source 92 applies the bridge input voltage V <b> 1 to the Wheatstone bridge circuit unit 91. Specifically, the DC power source 92 is bridged to both ends of the first Wheatstone bridge circuit 91a, the second Wheatstone bridge circuit 91b, the third Wheatstone bridge circuit 91c, and the fourth Wheatstone bridge circuit 91d. Input voltage V1 is applied.

  The bridge output voltage detector 93 detects the respective bridge output voltages V26 to V29 of the Wheatstone bridge circuit unit 91. The bridge output voltage V26 is a bridge output voltage of the first Wheatstone bridge circuit 91a. The bridge output voltage V27 is a bridge output voltage of the second Wheatstone bridge circuit 91b. The bridge output voltage V28 is a bridge output voltage of the third Wheatstone bridge circuit 91c. The bridge output voltage V29 is a bridge output voltage of the first Wheatstone bridge circuit 91d.

  The displacement detection unit 94 (detection unit in the present invention) receives the bridge output voltages V26 to V29 detected by the bridge output voltage detection unit 93. And the displacement amount detection part 94 calculates | requires the displacement amount (rotation angle) to the rotation direction of the surroundings of the front-back axis | shaft of FIG. 8 from the reference position based on the bridge output voltage V26-V29 input.

  Hereinafter, the detailed configuration of the displacement amount detection unit 94 and the displacement amount detection unit 94 based on the bridge output voltages V26 to V29, the second member 20 determines the displacement amount in the rotational direction around the front and rear axes in FIG. The method of obtaining will be specifically described.

  A detailed configuration of the displacement amount detection unit 94 will be described with reference to FIG. FIG. 11 is a block diagram illustrating a configuration of the displacement amount detection unit 94. As shown in FIG. 11, the displacement amount detection unit 94 includes a reference voltage vector storage unit 94a, an actual voltage vector detection unit 94b, a contribution calculation unit 94c, and a displacement amount calculation unit 94d.

  The reference voltage vector storage unit 94a stores in advance bridge output voltages V26 to V29 that are output according to the displacement of the second member 20 in each direction with respect to the first member 10.

  Specifically, the reference voltage vector storage unit 94a stores in advance bridge output voltages V26 to V29 when the second member 20 is rotationally displaced only about the front and rear axes in FIG. Here, the bridge output voltages V26 to V29 in this case are referred to as “reference voltage vector U1 in the rotation mode”.

  Further, the reference voltage vector storage unit 94a stores in advance bridge output voltages V26 to V29 when the second member 20 is displaced only in the vertical direction of FIG. Here, the bridge output voltages V26 to V29 in this case are referred to as “reference voltage vector U2 in the vertical mode”.

  Furthermore, the reference voltage vector storage unit 94a stores in advance bridge output voltages V26 to V29 when the second member 20 is displaced only in the left-right direction in FIG. Here, the bridge output voltages V26 to V29 in this case are referred to as “reference voltage vector U3 in the left-right mode”.

  Further, the reference voltage vector storage unit 94a stores in advance bridge output voltages V26 to V29 when the second member 20 is displaced only in the front-rear direction of FIG. Here, the bridge output voltages V26 to V29 in this case are referred to as “reference voltage vector U4 in the front-rear mode”.

  Here, the reference voltage vector U1 in the rotation mode, the reference voltage vector U2 in the up / down mode, the reference voltage vector U3 in the left / right mode, and the reference voltage vector U4 in the front / rear mode are collectively referred to as “reference voltage vector U”. That is, the reference voltage vector storage unit 94a stores the reference voltage vector U in advance.

  Here, Table 1 shows the relationship between each direction in which the second member 20 is displaced with respect to the first member 10 (hereinafter referred to as “deformation mode”) and the bridge output voltages V26 to V29. In the deformation mode of Table 1, the rotation mode is a mode when the second member 20 is rotationally displaced about the front-rear axis in FIG. The vertical mode is a mode when the second member 20 is displaced in the vertical direction in FIG. 8 with respect to the first member 10. The left / right mode is a mode when the second member 20 is displaced in the left / right direction in FIG. 8 with respect to the first member 10. The front-rear mode is a mode when the second member 20 is displaced in the front-rear direction of FIG. In Table 1, a1 to a8 indicate non-zero values.

  Here, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 each have a region having linearity in each mode. In the present embodiment, it is assumed that the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 are used in regions where the respective modes have linearity.

  Referring to Equation 7 in the first embodiment, the bridge output voltage V26 is proportional to the difference between the sixth resistor R6 and the seventh resistor R7. The bridge output voltage V27 is proportional to the difference between the seventh resistor R7 and the eighth resistor R8. The bridge output voltage V28 is proportional to the difference between the eighth resistor R8 and the ninth resistor R9. The bridge output voltage V29 is proportional to the difference between the ninth resistor R9 and the sixth resistor R6.

  Therefore, the reference voltage vectors U1 to U4 in each mode have linearity with respect to the bridge output voltages V26 to V29. In other words, it can be expressed as Equation 9.

  Here, the reference voltage vectors U1 to U4 in each mode are as shown in Equation 10.

  The actual voltage vector detection unit 94b inputs the bridge output voltages V26 to V29 detected by the bridge output voltage detection unit 93 in accordance with the actual displacement of the second member 20 with respect to the first member 10. Here, the actual displacement of the second member 20 with respect to the first member 10 is a state in which the above-described rotation mode, up-down mode, left-right mode, and front-back mode are variously mixed. The bridge output voltages V26 to V29 when the second member 20 is displaced with respect to the actual first member 10 are referred to as “actual voltage vector UR”.

  The contribution calculation unit 94c receives the reference voltage vector U and the actual voltage vector UR. The relationship between the reference voltage vector U and the actual voltage vector UR is expressed by Equation 11.

  Then, the contribution degree calculation unit 94c is based on the reference voltage vector U and the actual voltage vector UR having the relationship of Equation 11, and each of the rotation direction around the front and rear axes in FIG. 8 and the orthogonal three axis directions included in the actual voltage vector UR. The contributions k1 to k4 related to the components are calculated. That is, the contribution calculation unit 94c calculates a contribution k1 related to the rotation mode component, a contribution k2 related to the up / down mode component, a contribution k3 related to the left / right mode component, and a contribution k4 related to the front / rear mode component. Specifically, as shown in Expression 12, by performing a matrix operation, it is possible to calculate the contribution degree ki regarding the component of each mode i.

  The displacement calculation unit 94d receives the contribution k1 related to the rotational mode component around the front-rear axis in FIG. 8 calculated by the contribution calculation unit 94c. Further, the displacement amount calculation unit 94d receives the reference voltage vector U1 in the rotation mode stored in the reference voltage vector storage unit 94a. Then, the displacement amount calculation unit 94d calculates a relative displacement amount (relative rotation angle) of the second member 20 with respect to the first member 10 based on the contribution k1 related to the rotation mode component and the reference voltage vector U1 in the rotation mode.

  Thus, even when the second member 20 is displaced in the axial direction other than the rotation direction with respect to the first member 10, the relative displacement amount in the rotation direction can be reliably obtained.

  In the modification of the second embodiment, the second member 20 is described as being displaceable in the three orthogonal directions in addition to the displacement in the rotation direction with respect to the first member 10. Therefore, the Wheatstone bridge circuit section 91 is formed with four Wheatstone bridge circuits 91a to 91d. However, for example, when there is only one axial direction in which the second member 20 can be displaced relative to the first member 10, two Wheatstone bridge circuits 91 are sufficient for the Wheatstone bridge circuit portion 91. It is. That is, the Wheatstone bridge circuit may be formed in a number equal to or greater than the number of directions in which the second member 20 can be displaced relative to the first member 10 in the axial direction.

(5) Others In the first embodiment, the first conductive viscoelastic member 31 and the second conductive viscoelastic member 32 are configured to exist independently of each other. However, the present invention is not limited to this. . For example, like the conductive viscoelastic member 70 of the second embodiment, the entire space surrounded by the first member 10 and the second member 20 may be filled with the conductive viscoelastic member.

  On the other hand, in the second embodiment, the conductive viscoelastic member 70 is filled in the space surrounded by the first member 10 and the second member 20, but is not limited thereto. For example, you may make it form a conductive viscoelastic member independently like the 1st conductive viscoelastic member 31 and the 2nd conductive viscoelastic member 32 of 1st Embodiment.

  The displacement amount detection device described above can be applied to, for example, an engine mount. In this case, for example, the first member 10 is attached to the engine, and the second member 20 is attached to the vehicle body.

It is a figure which shows the machine structure part of the displacement detection apparatus 30 of 1st Embodiment. It is a figure which shows operation | movement of the mechanical structure part of the displacement detection apparatus 30 of 1st Embodiment. It is a figure which shows operation | movement of the mechanical structure part of the displacement detection apparatus 30 of 1st Embodiment. It is a figure which shows the circuit structure part of the displacement detection apparatus 30 of 1st Embodiment. It is a figure which shows the machine structure part of the displacement amount detection apparatus 50 of the deformation | transformation aspect of 1st Embodiment. It is a figure which shows the machine structure part of the displacement amount detection apparatus 60 of the deformation | transformation aspect of 1st Embodiment. It is a figure which shows the circuit structure part of the displacement detection apparatus 60 of the deformation | transformation aspect of 1st Embodiment. It is a figure which shows the machine structure part of the displacement detection apparatus 70 of 2nd Embodiment. It is a figure which shows the circuit structure part of the displacement detection apparatus 70 of 2nd Embodiment. It is a figure which shows the circuit structure part of the displacement detection apparatus 90 of the deformation | transformation aspect of 2nd Embodiment. 7 is a block diagram illustrating a configuration of a displacement amount detection unit 94. FIG.

Explanation of symbols

10: 1st member, 20: 2nd member,
30, 50, 60, 70, 90: displacement amount detection device,
31: 1st electroconductive viscoelastic member, 31a: 1st electroconductive viscoelastic member for X-axis,
31b: Y-axis first conductive viscoelastic member, 31c: Z-axis first conductive viscoelastic member,
32: 2nd electroconductive viscoelastic member, 32a: 2nd electroconductive viscoelastic member for X-axis,
32b: Y-axis second conductive viscoelastic member, 32c: Z-axis second conductive viscoelastic member,
33: first electrode, 33a: first electrode for X axis, 33b: first electrode for Y axis,
33c: Z-axis first electrode,
34: second electrode, 34a: second electrode for X axis, 34b: second electrode for Y axis,
34c: second electrode for Z axis,
35: third electrode, 35a: third electrode for X axis, 35b: third electrode for Y axis,
35c: Z-axis third electrode,
36: 4th electrode, 36a: 4th electrode for X-axis, 36b: 4th electrode for Y-axis,
36c: the fourth electrode for the Z axis,
41: Wheatstone bridge circuit,
41a: Wheatstone bridge circuit for X-axis,
41b: Y-axis Wheatstone bridge circuit,
41c: Wheatstone bridge circuit for Z-axis,
42: DC power supply,
43: Bridge output voltage detection unit, 43a: Bridge output voltage detection unit for X-axis,
43b: bridge output voltage detection unit for Y axis, 43c: bridge output voltage detection unit for Z axis,
44: Displacement amount detection unit, 44a: X axis displacement amount detection unit, 44b: Y axis displacement amount detection unit,
44c: Z-axis displacement detector 51: deformation absorber,
61: X-axis direction displacement detection unit 62: Y-axis direction displacement detection unit
63: Z-axis direction displacement detection unit,
71: conductive viscoelastic member, 72: first electrode, 73: second electrode, 74: third electrode, 75: fourth electrode, 76: fifth electrode, 77: sixth electrode,
81: 1st Wheatstone bridge circuit, 82: 2nd Wheatstone bridge circuit 83: DC power supply, 84: 1st bridge output voltage detection part,
85: second bridge output voltage detection unit, 86: displacement amount detection unit,
91: Wheatstone bridge circuit part,
91a-91d: Wheatstone bridge circuit,
92: DC power supply, 93: Bridge output voltage detector,
94: displacement amount detection unit, 94a: reference voltage vector storage unit,
94b: actual voltage vector detection unit, 94c: contribution calculation unit, 94d: displacement calculation unit,
411: first half-bridge circuit, 412: second half-bridge circuit,
811, 821: first half-bridge circuit, 812, 822: second half-bridge circuits 911a to 911d: first half-bridge circuit,
912a to 912d: second half bridge circuit

Claims (7)

The second member is disposed so as to be separated from the first member, and the second member can be displaced relative to the first member from a reference position in a predetermined axial direction among three orthogonal axes and is orthogonal to the first member. Among the three axes, at least one relative displacement is possible among relative movement and relative rotation in an axial direction different from the predetermined axial direction,
When the second member is relatively displaced from the reference position in the predetermined axial direction with respect to the first member, the relative displacement amount of the second member in the predetermined axial direction from the reference position with respect to the first member A displacement amount detection device for detecting
The first member and the second member are elastically connected to each other and are made of a conductive viscoelastic material whose impedance changes according to deformation, and the second member is moved from the reference position to the predetermined position with respect to the first member. A first conductive viscoelastic member that undergoes tensile deformation or compression deformation when relatively displaced in the axial direction;
The first member and the second member are elastically connected so as to be in parallel with the first conductive viscoelastic member, and are formed of a conductive viscoelastic material whose impedance changes according to deformation, A second member that undergoes tensile compression deformation that is inversely symmetric with respect to tensile compression deformation of the first conductive viscoelastic member when the second member is relatively displaced from the reference position in the predetermined axial direction with respect to one member. Conductive viscoelastic members of
A Wheatstone bridge circuit formed by the impedance of the first conductive viscoelastic member and the second conductive viscoelastic member;
A power supply for applying a bridge input voltage to the Wheatstone bridge circuit;
A detector that detects a relative displacement amount of the second member relative to the first member from the reference position in the predetermined axial direction based on a bridge output voltage of the Wheatstone bridge circuit;
Between the first member and / or the second member and the first conductive viscoelastic member, and between the first member and / or the second member and the second conductive viscoelastic member. A deformation absorbing material disposed between and having a spring constant smaller than that of the first conductive viscoelastic member and the second conductive viscoelastic member;
With
The second conductive viscoelastic member and the first conductive viscoelastic member are arranged opposite to the first conductive viscoelastic member in the predetermined axial direction so as to sandwich the second member. Displacement amount detection device characterized by being made. When the second member is located at the reference position with respect to the first member, the impedance of the second conductive viscoelastic member is substantially the same as the impedance of the first conductive viscoelastic member. Yes,
The Wheatstone bridge circuit is
A first half-bridge circuit in which an impedance of the first conductive viscoelastic member and a third impedance are connected in series;
An impedance of the second conductive viscoelastic member and a fourth impedance of substantially the same impedance as the third impedance are connected in series, and the impedance of the second conductive viscoelastic member and the first conductive viscoelasticity are connected. The first half-bridge circuit is connected in parallel so that the impedance of the member is directly connected, and the intermediate point between the impedance of the second conductive viscoelastic member and the fourth impedance is the first conductive A second half-bridge circuit connected to an intermediate point between the impedance of the viscous viscoelastic member and the third impedance;
With
The power supply applies the bridge input voltage to both ends of the first half bridge circuit and the second half bridge circuit,
The displacement detection device according to claim 1, wherein the bridge output voltage is a voltage difference between each intermediate point of the first half bridge circuit and the second half bridge circuit.   The displacement amount detection device according to claim 1, wherein the first conductive viscoelastic member and the second conductive viscoelastic member have substantially the same impedance when subjected to substantially the same deformation.   The second conductive viscoelastic member is made of substantially the same material as the first conductive viscoelastic member, and is substantially flush with the first conductive viscoelastic member with respect to a plane perpendicular to the predetermined axial direction. The displacement amount detection device according to claim 3, wherein the displacement amount detection device has a symmetrical shape. The second member is disposed so as to be separated from the first member, and the second member has a rotational direction around a predetermined axis from a reference position with respect to the first member and one or more axial directions among three orthogonal axes. Is relatively displaceable,
When the second member is relatively displaced with respect to the first member from the reference position in the rotational direction about the predetermined axis, the reference position of the second member relative to the first member is about the predetermined axis. A displacement amount detection device for detecting a relative displacement amount in the rotation direction of
The first member and the second member are elastically connected to each other and are made of a conductive viscoelastic material whose impedance changes according to deformation, and the second member is moved from the reference position to the predetermined position with respect to the first member. A first conductive viscoelastic member that undergoes tensile deformation or compression deformation when relatively displaced in a rotational direction about an axis;
The first member and the second member are elastically connected so as to be in parallel with the first conductive viscoelastic member, and are formed of a conductive viscoelastic material whose impedance changes according to deformation, When the second member is displaced relative to one member in the rotational direction around the predetermined axis from the reference position, the tensile compressive deformation is symmetric with respect to the tensile compressive deformation of the first conductive viscoelastic member. A second conductive viscoelastic member
The first member and the second member are elastically connected so as to be in parallel with the first conductive viscoelastic member and the second conductive viscoelastic member, and impedance changes according to deformation. One or more third conductive viscoelastic members made of a conductive viscoelastic material;
A first Wheatstone bridge circuit formed by the impedance of the first conductive viscoelastic member and the second conductive viscoelastic member;
The first conductive viscoelastic member and the second conductive viscoelastic member are selected from the first conductive viscoelastic member, the second conductive viscoelastic member, and the third conductive viscoelastic member. One or more second Wheatstone bridge circuits formed by two selected conductive viscoelastic members other than the combination of elastic members;
A power supply for applying a bridge input voltage to the first Wheatstone bridge circuit and the second Wheatstone bridge circuit;
Based on the bridge output voltage of the first Wheatstone bridge circuit and the second Wheatstone bridge circuit, a relative displacement amount of the second member relative to the first member in the rotational direction from the reference position to the predetermined axis is calculated. A detection unit to detect;
With
The total number of circuits of the first Wheatstone bridge circuit and the second Wheatstone bridge circuit is a predetermined number obtained by adding 1 to the number of directions in which the second member can be relatively displaced in the axial direction with respect to the first member. Set to more than a few,
The detector is
A reference voltage vector storage unit that stores in advance a reference voltage vector that is the bridge output voltage that is greater than or equal to the predetermined number that is output according to the relative displacement of the second member in each direction with respect to the first member;
An actual voltage vector detection unit that detects an actual voltage vector that is the bridge output voltage of the predetermined number or more that is output according to the relative displacement of the second member with respect to the actual first member;
Based on the reference voltage vector and the actual voltage vector, a contribution calculation unit that calculates contributions related to the rotation direction around the predetermined axis and the components in the axial direction included in the actual voltage vector;
The second member relative to the first member is based on the contribution related to the rotational direction component around the predetermined axis and the reference voltage vector related to the rotational direction around the predetermined axis stored in the reference voltage vector storage unit. A displacement amount calculation unit for calculating a relative displacement amount in a rotation direction around the predetermined axis from a reference position;
A displacement amount detection device comprising: The displacement detection device according to claim 5 , wherein the first conductive viscoelastic member and the second conductive viscoelastic member have substantially the same impedance when subjected to substantially the same deformation. The displacement amount detection device according to any one of claims 1 to 6 , wherein the first conductive viscoelastic member and the second conductive viscoelastic member are plural.

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