Vibration actuators, multi-axis stages, articulated robots, continuous robots

Abstract

To provide a vibration type actuator, a device, a multi-axis stage unit, and an articulated robot, capable of preventing unwanted vibrations from occurring on the vibration type actuator and increasing output per volume.SOLUTION: The vibration type actuator comprises a vibration body including an elastic body and an electromechanical energy conversion element and a contact body long in a predetermined direction and in contact with the vibration body. The vibration type actuator has a configuration in which the vibration body and the contact body move relatively in the predetermined direction by the vibrations of the vibration body. An end portion of the long contact body is covered circumferentially with respect to the predetermined direction by a viscoelastic body.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a vibration type actuator, a multi-axis stage, a multi-joint robot, and a continuum robot in which a vibrating body and a contact body move relative to each other.

Background Art

[0002] There have been proposed a vibration type actuator that generates vibrations combining different vibration modes in a vibrating body to obtain a thrust between the vibrating body and a contact body, and a vibration type actuator that changes the frictional force between the vibrating body and the contact body by exciting in a single vibration mode.

[0003] In Patent Document 1, in order to avoid the generation of noise (also called ringing) caused by unnecessary vibrations and the reduction of drive efficiency, a vibration absorbing member is provided between a relative motion member (contact body) and a second base member. A configuration for absorbing unnecessary vibrations generated in the relative motion member (contact body) by the elliptical motion generated by the vibrator (vibrating body) is disclosed by such a configuration.

[0004] However, the configuration disclosed in Patent Document1 tends to have a small output per volume or weight, and there is a problem in the space use efficiency. As the first reason, it is necessary to have a second base member that supports one surface of the second base member. Since the second base member is larger than the relative motion member (contact body) and the entire ultrasonic motor (vibration type actuator) becomes larger, miniaturization becomes difficult. The second reason is that since a vibration absorbing member is provided over the entire surface between the relative motion member (contact body) and the second base member, the surface that can be used for the frictional sliding of the relative motion member (contact body) is inevitably limited. Therefore, since the vibration absorbing member is attached to the surface facing the frictional sliding surface, it cannot be used for driving.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In view of the above circumstances, the object of the present invention is to provide a vibrating actuator, a device, a multi-axis stage unit, and a multi-joint robot that can suppress unwanted vibrations generated in a vibrating actuator and increase the output per unit volume. [Means for solving the problem]

[0007] The vibration-type actuator according to the present invention comprises a vibrating body including an elastic body and an electromechanical energy conversion element, The system comprises a contact body that is elongated in a predetermined direction and in contact with the vibrating body, A vibrating actuator configured such that the vibrating body and the contact body move relative to each other in a predetermined direction due to the vibration of the vibrating body, The end of the long contact body is characterized in that it is covered with a viscoelastic material in the circumferential direction with respect to the predetermined direction. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a small vibration-type actuator that can suppress the generation of unwanted vibrations. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the schematic configuration of the vibrating body. [Figure 2] This is a schematic diagram illustrating the vibration modes excited in a vibrating body. [Figure 3] These are a front view, a bottom view, and a side view showing the schematic configuration of a vibrating actuator according to the first embodiment. [Figure 4] This is a front view showing a schematic configuration of a vibratory actuator according to the first embodiment. [Figure 5]It is a diagram for explaining the configuration of a connecting portion for connecting vibrating body units and its modified examples. [Figure 6] It is a plan view, a front view, and a side view showing a schematic configuration of a vibration type actuator according to the first embodiment. [Figure 7] It is a front view showing a schematic configuration of a vibration type actuator according to the second embodiment. [Figure 8] It is a plan view and a front view showing a schematic configuration of a vibration type actuator according to the second embodiment. [Figure 9] It is a plan view, a front view, and a bottom view showing a schematic configuration of a contact body unit and a contact body according to the second embodiment. [Figure 10] It is a schematic diagram for explaining a method of supporting a contact body by a plurality of vibrating bodies. [Figure 11] It is a diagram for explaining a configuration example in which displacement detection means is provided in a vibrating body unit. [Figure 12] It is a diagram for explaining a schematic configuration of an actuator unit according to the third embodiment. [Figure 13] It is a plan view showing a schematic configuration of a device according to the fourth embodiment. [Figure 14] It is a diagram for explaining a schematic configuration of a device according to the fifth embodiment. [Figure 15] It is a plan view showing a schematic configuration of a multi-axis stage according to the sixth embodiment. [Figure 16] It is a plan view showing a schematic configuration of a multi-joint robot according to the seventh embodiment. [Figure 17] It is a plan view showing a schematic configuration of a continuum robot according to the eighth embodiment. [Figure 18] It is a perspective view showing a schematic configuration of a wire-driven manipulator of a continuum robot according to the eighth embodiment.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] First, the vibrating body and the contact body that are commonly used in the vibration type actuator according to each of the embodiments described later will be described. FIG. 1(a) is a plan view showing a schematic configuration of the vibrating body 1 that constitutes the vibration type actuator, FIG. 1(b) is a front view of the vibrating body 1, and FIG. 1(c) is a side view of the vibrating body 1.

[0012] For the sake of convenience of explanation, as shown in FIGS. 1(a) to 1(c), a rectangular coordinate system composed of an x-axis (x direction), a y-axis (y direction), and a z-axis (z direction) is set for the vibrating body 1. The z direction is the thickness direction of the vibrating body 1 and is the protruding direction of the protruding portions 2a provided at two locations (details will be described later). The y direction is the longitudinal direction of the vibrating body 1 and is the direction connecting the two protruding portions 2a. The x direction is the short side direction (width direction) of the vibrating body 1 and is a direction orthogonal to the y direction and the z direction. For each direction shown in FIG. 1, the direction from the starting point to the ending point of the arrow indicating each direction is defined as the positive direction (+ direction), and the direction from the ending point to the starting point is defined as the negative direction (- direction).

[0013] The vibrating body 1 includes an elastic body 2 having elasticity and an electro-mechanical energy conversion element 3 joined to the elastic body 2. The electro-mechanical energy conversion element 3 is, for example, a piezoelectric element that converts voltage into force by the inverse piezoelectric effect, and is configured by providing electrodes to which a predetermined voltage is applied on the front and back surfaces of a rectangular thin plate-shaped piezoelectric ceramic. The elastic body 2 has protruding portions 2a, a suspension portion 2b, a support end portion 2c, and a base portion 2d. The two protruding portions 2a are provided so as to protrude in the +z direction on the surface opposite to the surface where the electro-mechanical energy conversion element 3 is joined in the rectangular flat base portion 2d. Note that the protruding portions 2a and the base portion 2d may be integrally formed by pressing or the like, or may be provided by joining a protruding member to the base portion 2d by a predetermined method. The support end portion 2c is a rectangular flat portion for fixing the vibrating body 1 to a holding portion 8 described later. The suspension portion 2b is a rectangular flat portion that serves to connect the base portion 2d and the support end portion 2c.

[0014] Here, the projection 2a will be described in more detail. Figure 2(c) is a cross-sectional view showing the schematic structure of the projection 2a. A friction material 2f is provided on the surface of the base material 2e of the projection 2a. Here, the material of the base material 2e is the same as the material of the base portion 2d (not shown in Figure 1(d)). When martensitic stainless steel is used for the base material 2e, the friction material 2f can be an electroless nickel plating film, a chrome plating film, a hardened layer by quenching, a nitrided film by ion nitriding treatment, etc. Alternatively, by using fiber-reinforced engineering plastics such as PEEK-CF30 or hard ceramics for the base material 2e, a configuration can be adopted in which the base material 2e also serves as the friction material 2f (in this case, there is no distinction between the base material 2e and the friction material 2f).

[0015] Next, we will explain the two vibration modes excited in the vibrating body 1. Figure 2(a) is a schematic diagram illustrating the first vibration mode excited in the vibrating body 1, and Figure 2(b) is a schematic diagram illustrating the second vibration mode excited in the vibrating body 1. Note that the deformation of the vibrating body 1 is exaggerated in Figure 2. Also, for the sake of explanation, a contact body 4 that is in contact with the vibrating body 1 and receives thrust (frictional driving force) from the vibrating body 1 is shown in Figure 2.

[0016] The contact body 4 is a member that is elongated in the y-direction in the figure and is configured to contact the projection 2a of the vibrating body 1. The vibrations generated in the vibrating body 1 allow the vibrating body 1 and the contact body 4 to move relative to each other in the y-direction. The contact between the contact body 4 and the vibrating body 1 is not limited to direct contact without any other members interposed between the contact body 4 and the vibrating body 1. The contact between the contact body 4 and the vibrating body 1 may be indirect contact with other members interposed between the contact body 4 and the vibrating body 1, as long as the vibrations generated in the vibrating body 1 cause relative movement between the vibrating body 1 and the contact body 4.

[0017] "Other components" are not limited to components independent of the contact body and the vibrating body (for example, high-friction materials made of sintered bodies). "Other components" may also be surface-treated parts formed on the contact body or vibrating body by plating, nitriding, or the like.

[0018] The first vibration mode shown in Figure 2(a) is a second-order out-of-plane bending vibration mode in which three nodal lines substantially parallel to the x-direction occur in the base portion 2d, and this vibration mode excites vibrations that displace in the y-direction at the tips of the two protrusions 2a. On the other hand, the second vibration mode shown in Figure 2(b) is a first-order out-of-plane bending vibration mode in which two nodal lines substantially parallel to the y-direction occur in the base portion 2d, and this vibration mode excites vibrations that displace in the z-direction at the tips of the two protrusions 2a.

[0019] By applying multiple alternating voltages with different phases to the electromechanical energy conversion element 3, both the first and second vibration modes are excited, causing elliptical motion in the yz plane at the tips of the two protrusions 2a. This elliptical motion in the yz plane causes the contact body 4 to receive a thrust in the y direction, and as a result, it becomes possible to move the vibrating body 1 and the contact body 4 relative to each other in the y direction.

[0020] When no voltage is applied to the electromechanical energy conversion element 3, the static friction force between the projection 2a and the contact body 4 acts as a holding force that maintains the relative position between the vibrating body 1 and the contact body 4. Furthermore, by adjusting the voltage applied to the electromechanical energy conversion element 3 to adjust the amplitude of the vibration excited in the vibrating body 1, the contact time between the projection 2a and the contact body 4 can be adjusted, thereby changing the apparent friction force. For example, by exciting only the vibration of the second vibration mode in the vibrating body 1 and increasing its vibration amplitude, the friction force generated between the projection 2a and the contact body 4 can be reduced.

[0021] By performing these controls, for example, in a configuration where a contact body 4 moves relative to a vibrating body 1, it is possible to adjust the magnitude of the reaction force when an external force other than the contact pressure with the vibrating body 1 is applied to the contact body 4 to move it. For example, it is possible to adjust the operating reaction force that the user receives when the user directly applies an external force to the contact body 4 to move it.

[0022] In the vibrating actuator shown in Figure 2, the tip of the projection 2a is in contact with the contact body 4. The surface of the contact body 4 that contacts the projection 2a (friction sliding surface) is provided with friction material 4a, and the surface of the projection 2a is provided with friction material 2f. This allows for stable friction sliding characteristics to be obtained between the elastic body 2 and the contact body 4. The material and formation method of the friction material 4a are the same as those of the friction material 2f.

[0023] Next, the materials used for the vibrating body 1 and the contact body 4 will be described. Materials used for the elastic body 2 include martensitic stainless steel with low vibration loss and high-toughness ceramics such as partially stabilized zirconia (PSZ). Other materials include engineering plastics (FRP) such as polyether ether ketone (PEEK-CF30) reinforced with approximately 30 wt% carbon fiber, semiconductors such as silicon carbide (SiC), and aluminum alloys. Piezoelectric ceramics such as lead titanate-lead zirconate (PZT) are used for the electromechanical energy conversion element 3. For the contact body 4, martensitic stainless steel, aluminum alloys, FRP such as PEEK-CF30, and fine ceramics such as PSZ and alumina (aluminum oxide) are used. Note that the materials used for the vibrating body 1 and the contact body 4 are not limited to those listed here. [Examples]

[0024] Figure 3 illustrates a contact body 4 and a vibrating body 1 in a simulated manner to illustrate a vibrating actuator in the first embodiment of the present invention. The vibrating actuator of this embodiment comprises a vibrating body including an elastic body and an electromechanical energy conversion element, and a contact body that is elongated in a predetermined direction and in contact with the vibrating body. This vibrating actuator is configured such that the vibrating body and the contact body move relative to each other in the predetermined direction due to the vibration of the vibrating body. A characteristic feature is that the end of the elongated contact body is covered with a viscoelastic material in the circumferential direction with respect to this predetermined direction.

[0025] Figure 3(a) is a front view of a contact body 4 with cylindrical viscoelastic bodies 6a and 6b fitted to both ends, and a vibrating body 1 pressed against the contact body 4. Figures 3(h) and 3(i) are right side views thereof. The x, y, and z directions are set according to the x, y, and z directions set for the vibrating body 1, as shown in Figure 3. In addition, including the vibrating actuator according to other embodiments described below, the y direction is the left-right direction of the vibrating actuator, with the +y side being the right side and the -y side being the left side. The z direction is the up-down direction of the vibrating actuator, with the +z side being the upper side and the -z side being the lower side. An example of how to press the vibrating body 1 against the contact body 4 will be described later. Figure 3(b) is a front view of the contact body 4, exaggerating the out-of-plane bending modes that occur in the contact body 4. When the vibrating body 1 is excited by the first vibration mode, the second vibration mode, or both, if the frequency of that vibration mode is close to the natural frequency of the natural vibration mode of the contact body 4, the contact body 4 will be excited by that natural vibration mode. For example, if the contact body 4 is excited by an out-of-plane vibration mode like the one shown in Figure 3(b), which vibrates in the z direction with wavelength λ relative to a plane parallel to the xy plane, the contact body 4 and the projection 2a of the vibrating body 1 will intermittently alternate between contact and non-contact states. This will produce a banging noise and lead to a decrease in thrust. Furthermore, the difference between the driving frequency that excites the vibrating body 1 and the natural frequency of the natural vibration mode that excites the contact body 4 will occur as a squeal, which can also lead to a decrease in thrust. As shown in Figure 3(a), cylindrical viscoelastic bodies 6a and 6b are fitted tightly onto the contact body 4. This ensures that the contact body 4 and the viscoelastic body are in close contact at the point where strain occurs, in response to the strain generated in response to the deformation of the contact body 4 in the natural vibration modes that occur in the contact body 4 as unwanted vibrations. As a result, it is possible to absorb the excitation energy by utilizing the expansion and contraction of the viscoelastic bodies 6a and 6b, thereby reducing the vibration amplitude of the unwanted vibrations. The preferred shape of the viscoelastic body will now be described. In this embodiment, the viscoelastic bodies 6a and 6b are cylindrical in shape, and the contact body 4 is a rod-shaped rectangular parallelepiped, but it is preferable that the viscoelastic bodies 6a and 6b and the contact body are in contact on four surfaces. In other words, it is preferable that the sum of the circumferential outer dimensions in the cross section parallel to the xz cross section of the contact body 4 is slightly longer than the inner circumference of the viscoelastic bodies 6a and 6b when they are not attached.Generally, simply attaching a viscoelastic material by its adhesive properties makes it difficult to completely bond the strained area of ​​the contact body to the viscoelastic material. A small air layer is inevitably created, making it difficult to absorb the excitation energy mentioned above, and reducing the effect of suppressing unwanted vibrations. Furthermore, when attaching a viscoelastic material using an adhesive, the presence of an adhesive layer between the viscoelastic material and the contact body causes the viscoelastic properties of the adhesive layer to dominate over the viscoelastic properties of the viscoelastic material, making it impossible to utilize the high vibration damping performance of materials such as butyl rubber. This invention utilizes the elasticity of the viscoelastic material to enable the use of a tubular viscoelastic material whose hole cross-sectional area when relaxed is smaller than the xz cross-sectional area of ​​the contact body 4. In other words, when the viscoelastic material is not attached to the contact body, the inner circumference of the cylindrical member is smaller than the sum of the lengths around the contact body in a cross-section normalized to a predetermined direction.

[0026] By attaching the viscoelastic bodies 6a and 6b to the contact body while extending the holes radially, it is possible to prevent the interposition of air layers or adhesive layers and increase the area of ​​contact between the inside of the viscoelastic bodies 6a and 6b and the contact body 4. Furthermore, a longer length in the y direction of the viscoelastic bodies 6a and 6b allows for covering more of the areas where strain occurs in the contact body due to unwanted vibrations. As the amount of excitation energy absorbed by the viscoelastic bodies increases, the effect of suppressing unwanted vibrations is high. For example, if the y-direction dimensions of the two viscoelastic bodies 6a and 6b shown in Figure 3(a) are L1 and L2 respectively, it is preferable that the sum of L1 and L2 is at least half a wavelength (λ / 2 or more) of the vibration wave of the vibration mode in the vibration of the contact body excited by the vibration shown in Figure 3(b). Another criterion for setting the dimensions of the viscoelastic bodies is that the sum of L1 and L2 is at least the distance between adjacent protrusions 2a, which corresponds to approximately one wavelength of the first vibration mode that excites the vibrating body 1. If a viscoelastic body is not provided at both ends but only at one end, it is preferable that the y-direction dimension of the viscoelastic body be greater than or equal to the sum of L1 and L2. Furthermore, it is preferable that the total length of the y-direction dimensions of the viscoelastic body be greater than or equal to the distance between adjacent nodal lines in the vibrations occurring in the oscillator.

[0027] Furthermore, it is preferable that the sum of the lengths of the y-direction dimensions of the viscoelastic material is greater than or equal to the distance between the centers of multiple adjacent protrusions in the elastic material constituting the oscillator.

[0028] Next, regarding the position where the viscoelastic body is placed, it is preferable to place it at a position that includes the antinode of the vibration mode where the contact body 4 is most strained by unwanted vibrations, thereby enabling more effective damping of unwanted vibrations. Suitable materials for the viscoelastic body will now be described. A viscoelastic body is a material that has both viscosity and elasticity, and for example, rubber and resin are suitable. As rubber materials, butadiene rubber, butyl rubber, and silicone rubber, which have high vibration damping performance, are particularly suitable. A viscoelastic body can be formed inexpensively by cutting a hollow (tubular) molded rubber or resin material. By fitting the cylindrical viscoelastic bodies 6a and 6b shown in Figure 3(a), it is possible to suppress unwanted vibrations without increasing the size of the vibration actuator.

[0029] Next, the width dimensions of the contact body 4 and the viscoelastic body 6 will be explained using Figures 3(h) and 3(i). Figure 3(h) is a right side view when the vibrating body 1 is supported by the holding part 8, which will be described later. If the width dimensions in the x-direction of the contact body 4, the viscoelastic body 6, and the holding part 8 are W4, W6, and W8, respectively, then as shown in Figure 3(h), it is possible to miniaturize the vibrating actuator by setting W4≦W8 or W6≦W8.

[0030] In other words, in the cross-section of the vibrating actuator perpendicular to the predetermined direction, the width dimension of the viscoelastic body can be made smaller than the width dimension of the vibrating body or the width dimension of the holding part, thereby enabling miniaturization of the vibrating actuator.

[0031] Furthermore, as shown in Figure 3(i), if the width dimension of the vibrating body 1 in the x-direction is W1, then by setting W4≦W1 or W6≦W1, it becomes possible to further miniaturize the vibrating actuator.

[0032] Next, an embodiment of the viscoelastic body for further enhancing the effect of suppressing unwanted vibrations in this embodiment will be described using Figures 3(c) to 3(g). Figure 3(c) is a front view of a vibrating actuator showing a state in which, in addition to the viscoelastic body configuration shown in Figure 3(a), a viscoelastic body 6c is attached to the opposing surfaces of the friction sliding surfaces where the vibrating body 1 and the contact body 4 come into contact. The viscoelastic body configuration shown in Figure 3(c) makes it possible to enhance the effect of suppressing unwanted vibrations generated in the contact body 4 compared to the viscoelastic body configuration shown in Figure 3(a). In this case, the viscoelastic bodies 6a, 6b, and 6c may be formed as separate bodies or as an integral body. The surface of the contact body 4 where the vibrating body 1 and the contact body 4 come into contact has an exposed area in the y-axis direction where no viscoelastic body is provided. This exposed area is provided in the y-axis direction and in the circumferential direction with respect to the y-axis to such an extent that the relative movement between the vibrating body 1 and the contact body 4 is not hindered. The length of the exposed area in the y-axis direction should be configured to be longer than the range of relative movement between the vibrating body 1 and the contact body 4, and the width of the exposed area in the x-direction should be configured to be longer than the width of the vibrating body 1 itself or the width of the projection 2a.

[0033] Figures 3(d) and 3(e) show further examples of the configuration of a vibratory actuator. Figure 3(d) is a front view of the vibratory actuator with a viscoelastic body 6d attached to the contact body 4, and Figure 3(e) is a bottom view. The viscoelastic body 6d has a length dimension L4 in the y direction, and a window portion is provided on the lower surface of the central part to form an exposed area with a dimension L3 in the y direction. As shown in the figures, by attaching the viscoelastic body 6d to the contact body 4, the friction sliding surface 4b is exposed, enabling contact with the vibrating body 1. This vibratory actuator makes it possible to enhance the effect of suppressing unwanted vibrations generated in the contact body 4 compared to the vibratory actuator configurations shown in Figures 3(a) and 3(c). In addition, the viscoelastic body can be formed inexpensively by simple methods such as cutting out a part of a tubularly molded rubber or resin material with a die.

[0034] Figures 3(f) and 3(g) show further examples of the configuration of a vibratory actuator. The configuration of the viscoelastic body 6f shown in Figures 3(f) and (g) makes it possible to further enhance the effect of suppressing unwanted vibrations compared to the vibratory actuators shown in Figures 3(d) and (e). Figure 3(f) is a front view of the vibratory actuator with the viscoelastic body 6f attached to the contact body 4, and Figure 3(g) is a bottom view. The viscoelastic body 6f, like the viscoelastic body 6d, has a length dimension L3 in the y direction, and a window portion with a dimension L4 in the y direction is provided on the lower surface of the central part. As shown in the figures, the x-direction dimension of the window portion of the viscoelastic body 6f is smaller than that of the viscoelastic body 6d. That is, the viscoelastic body 6f covers a part of the friction sliding surface 4b, and covers the contact body 4 in a range where contact with the tip of the projection 2a of the vibrating body 1 is not hindered. In other words, the viscoelastic body 6f is fitted into the contact body 4 such that the friction sliding surface 4b is exposed to a slightly wider extent and substantially the same length as the width of the vibrating body 1. This configuration of the vibrating actuator makes it possible to enhance the effect of suppressing unwanted vibrations generated in the contact body 4 compared to the configuration of the vibrating actuator shown in Figures 3(d) and 3(e). Furthermore, it is possible to enhance the effect of suppressing unwanted vibrations caused by multiple vibration modes such as in-plane vibration and torsional vibration. In addition, since the window portion of the viscoelastic body 6f has a smaller dimension in the x direction compared to the viscoelastic body 6d, it is possible to improve the adhesion to the contact body compared to the viscoelastic body 6d by utilizing the elastic contraction force of the viscoelastic body, thus also enhancing the effect of suppressing unwanted vibrations. Similarly, in this case as well, the viscoelastic body can be formed inexpensively by simple methods such as cutting out a part of a tubularly molded rubber or resin material with a die.

[0035] In the above example, the out-of-plane bending vibration mode occurring in the contact body 4 was used as an example for explanation in Figure 3(b). However, the present invention is also effective for other natural vibration modes such as in-plane vibration modes and torsional vibration modes. For vibrations such as in-plane vibration and torsional vibration, vibration suppression similar to that in the case of out-of-plane vibration is possible by providing a viscoelastic body so as to include the antinodes with large strain. As shown in Figures 3(c) to (g), the viscoelastic body is in close contact with the ends and the sides of the contact body 4 other than the friction sliding surface. In this way, even for multiple vibration modes where the locations of the antinodes with large strain differ, unwanted vibrations caused by various vibration modes can be suppressed by covering the position of each antinode.

[0036] The above describes examples of viscoelastic body configurations, but as shown in the examples in Figure 3, a configuration in which the viscoelastic body does not cover the outermost end of the long contact body may also be adopted. The effect of the viscoelastic body covering the outermost end of the contact body on suppressing unwanted vibrations is small. Therefore, a configuration in which the viscoelastic body does not cover the outermost end of the long contact body is also within the scope of the present invention. In this embodiment, an example was given in which the xz cross-section of the contact body is rectangular, and the four sides other than the surface parallel to the xz plane (= outermost end) are covered to improve the adhesion between the contact body and the viscoelastic body.

[0037] Next, the support structure for the contact body 4 and the vibrating body 1 in the vibrating actuator 101 of this embodiment will be explained with specific examples using Figures 4 to 6.

[0038] Figure 4 is a front view showing a schematic configuration of a vibrating actuator 101 according to the first embodiment. The vibrating actuator 101 comprises a vibrating unit 5 including a vibrating body 1, and a contact body 4 that contacts the vibrating body 1 of the vibrating unit 5.

[0039] The vibrating body unit 5 comprises a vibrating body 1, a nonwoven fabric 16, a pressurizing part 7, a holding part 8, a rotating support part 9, and a reaction force receiving part 10. The vibrating body unit 5 has a pressurizing support structure capable of exciting vibrations of the vibration modes shown in Figure 2. In one vibrating body unit 5, the support end 2c of the elastic body 2 constituting the vibrating body 1 is fixed to the upper surface of the wall portion on the y-direction side, which is the side wall of the holding part 8. The nonwoven fabric 16 is arranged on the back side of the electromechanical energy conversion element 3 (the side opposite to the surface joined to the elastic body 2). The nonwoven fabric 16 is a cloth-like member made of nonwoven material such as wool felt or glass wool, and supports the vibrating body 1 while maintaining the vibration modes generated in the vibrating body 1. When the pressurizing part 7 presses the vibrating body 1 against the contact body 4 via the nonwoven fabric 16, the projection 2a of the vibrating body 1 comes into contact with the contact body 4. Since the vibrating body 1 is fixed to the holding part 8, the holding part 8 is pressed toward the contact body 4 together with the vibrating body 1.

[0040] The method for installing the nonwoven fabric 16 will now be explained. Figure 5(a) is a partial front view of the vibrating body unit 5, and Figure 5(b) is a bottom view of the vibrating body unit 5. The holding part 8 is provided with a through hole 8e that penetrates in the z direction, and when the holding part 8 is viewed from the -z direction side with the vibrating body 1 held by the holding part 8, the electromechanical energy conversion element 3 is exposed through the through hole 8e. The nonwoven fabric 16 (hatched area in Figure 5(b)) is installed inside the through hole 8e so as to be in contact with the electromechanical energy conversion element 3.

[0041] Although not shown in the diagram, a flexible wiring board for supplying power to the electromechanical energy conversion element 3 is actually attached to the back surface (the surface in the -z direction) of the electromechanical energy conversion element 3. Therefore, more precisely, the nonwoven fabric 16 is installed so as to be in contact with the flexible wiring board attached to the electromechanical energy conversion element 3.

[0042] The pressurizing section 7 is formed when the projection 2a of the vibrating body 1 presses against the contact body 4 with a predetermined pressing force via the nonwoven fabric 16. The pressurizing section 7 is composed of elastic components such as a coil spring, leaf spring, disc spring, wave washer, rubber, or air tube that exhibit a restoring force in the z direction. Figure 4 shows an example in which a compression coil spring is used in the pressurizing section 7.

[0043] The reaction force receiving portion 10 supports the rotation support portion 9, and the rotation support portion 9 is configured to rotate in a roller-like manner relative to the reaction force receiving portion 10. The reaction force receiving portion 10 and the rotation support portion 9 are positioned to contact the upper surface of the contact body 4 in the Z direction. This is the side of the contact body 4 opposite to the contact surface with the projection 2a. The projection 2a on the vibrating body 1 receives a reaction force from the pressure applied to the contact body 4. In this way, the contact body 4 is supported by the vibrating body unit 5 and the pair of the reaction force receiving portion 10 and the rotation support portion 9.

[0044] On the other hand, two opposing pairs of reaction force receiving parts 10 and rotational support parts 9 are provided at positions offset in the negative y-axis direction from this pair, so that the contact body is sandwiched in the z-direction by three rotational support parts 9 and one vibrating body unit 5. In the vibrating actuator 101, the reaction force receiving parts 10 are attached to a support member 15, and the rotational support parts 9 are rotatably supported around an axis parallel to the x-axis, forming a roller. The support member 15 is a base material for assembling various components that constitute the vibrating actuator 101. The support member 15 can be configured to enclose the reaction force receiving parts 10 and rotational support parts 9, the vibrating body unit 5, and a part of the contact body 4.

[0045] The support member 15 can be fixed to the frame of an unillustrated device, etc., thereby mounting the vibration actuator 101 on the device, and the contact body 4 can be configured to move in the y-direction relative to the fixed support member 15.

[0046] The contact body 4 is supported by the support member 15 in a manner that allows it to move in the y-direction by the thrust it receives from the vibrating bodies 1, each of the vibrating body units 5. Specifically, four rollers that can rotate about an axis parallel to the z-axis are provided on the support member 15 as contact body support parts 12 that support the contact body 4 so that it can move. The four contact body support parts 12 act as linear guides that allow the contact body 4 to move in the y-direction while constraining its degrees of freedom in the x-direction.

[0047] The holding portion 8 of the vibrating body unit 5 is attached to the support member 15 by a connecting portion 14. Figure 5(c) is a perspective view showing the schematic configuration of the connecting portion 14. The connecting portion 14 has a link member 14b (connecting portion) with two holes provided at a predetermined interval so as to penetrate in the x direction, and cylindrical pins 14a (shaft portions) that are inserted into the two holes of the link member 14b and attached to the link member 14b substantially parallel to each other. The two pins 14a are fixed to the link member 14b in their respective holes. Note that the two pins 14a and the link member 14b may be integrally (seamlessly) molded in an H shape when viewed from the z direction.

[0048] One of the two pins 14a is positioned at a distance a in the +z direction from the reference origin O of the support member 15 shown in Figure 4, so that the connecting portion 14 has rotational degrees of freedom with the central axis of the pin 14a positioned on the support member 15 as its center of rotation. On the other hand, the center of the contact body 4 is positioned at a distance b in the +z direction from the center of the pin 14a positioned on the support member 15. In this way, the contact body 4 is accurately positioned at a distance a+b in the +z direction from the reference origin O of the support member 15. With the above configuration, the vibrating body unit 5 becomes slidable in the z direction, and even if the contact body 4 has a wavy shape in the yz plane due to manufacturing errors, etc., the vibrating body unit 5 can conform to the shape of the contact body 4 and press against it.

[0049] Next, a modified form of the vibration-type actuator 102 according to the first embodiment will be described using Figure 6. The difference from the vibration-type actuator 102 described above is that both ends of the contact body 4 are fixed to the support member 15.

[0050] Figures 6(a) and 6(b) are a plan view and a front view, respectively, showing the schematic configuration of the vibrating actuator 102. The vibrating actuator 102 comprises a vibrating body unit 11 and a contact body 4 that contacts the vibrating body 1 of the vibrating body unit 5. The contact body 4 is fixed, and the vibrating body 1 moves relative to it. Furthermore, for components of the vibrating actuator 102 that correspond to components of the vibrating actuator 101 (see Figure 4), the same names and reference numerals are used, and explanations of their common functions and configurations are omitted.

[0051] The vibration actuator 102 comprises a vibrating body unit 11 and a contact body 4. In the vibration actuator 102, both ends of the contact body 4 are fixed to a support member 15, and two viscoelastic bodies 6 are fitted at the antinodes of out-of-plane vibration modes that occur in the contact body 4 at a frequency near the drive frequency applied to the vibrating body 1. The vibrating body unit 11 has a vibrating body 1, a spacer 19, a pressurizing part 13, a rotating support part 9, and a holding part 18 for integrating these into a single unit. In the vibrating body unit 11, a spacer 19 with a nonwoven fabric 16 attached is placed inside the holding part 18. With the nonwoven fabric 16 in contact with the electromechanical energy conversion element 3 that constitutes the vibrating body 1, the support ends 2c at both ends of the vibrating body 1 in the y-direction are fixed to the holding part 18. A schematic configuration for explaining the support relationship between the vibrating body unit 11 and the contact body 4 is shown in Figure 6(c).

[0052] As shown in Figure 6(c), the holding portion 18 is provided with an opening 18a, and the x-direction dimension of the opening is set to be larger than the x-direction width dimension of the contact body 4. By providing an appropriate gap in this way, the opening 18a functions as a linear guide for the vibrating body unit 11 to move in the y-direction.

[0053] A rotating support part 9 is provided on the opposite side of the contact surface between the contact body 4 and the projection 2a (above the contact body 4 (+z side)), and receives the reaction force of the force that presses the projection 2a of the vibrating body 1 against the contact body 4. The rotating support part 9 of the vibrating actuator 101 is supported so as to be rotatable about an axis parallel to the x-axis, and a compression coil spring is positioned as a pressurizing part 13 relative to the rotating support part 9. In this way, the pressurizing reaction force of the pressurizing part 13 (the force that causes the compression coil spring to extend in the z direction) presses the rotating support part 9 against the contact body 4, and at the same time, the tip of the projection 2a of the vibrating body 1 is pressed against the contact body 4.

[0054] With the above configuration, the vibrating actuator 102 allows the vibrating unit 11 to move in the y-direction relative to the contact body 4. At this time, as shown in Figure 6(a), by providing an opening 15a in the support member 15, the upper surface of the vibrating unit 11 can be exposed to the outside, and it is possible to connect the vibrating unit 11 to a driven object (not shown).

[0055] In this embodiment, an embodiment in which a cylindrical or tubular viscoelastic body made of rubber or the like is fitted into the contact body has been described, but the method of forming the viscoelastic body is not limited to this. Several other examples of means for forming the viscoelastic body are shown below. As a first method of formation, it is also possible to wrap a tape-like viscoelastic body made of adhesive and a base material around the contact body. This method can be easily carried out even after the assembly of the vibrating actuator, and is therefore effective as an emergency measure against abnormal noises that occur during operation. By appropriately selecting the thickness and material of the base material, unwanted vibrations can be effectively suppressed. As a second method of formation, it is also possible to carry out the process by dipping, which is a coating method in which the contact body is immersed in liquid rubber or resin. In this case, the outermost end of the contact body may be covered with the viscoelastic body, but this does not particularly result in a loss of effect in suppressing unwanted vibrations. In dipping, for areas where the adhesion of the viscoelastic body may cause any inconvenience, it is possible to apply a mask to the contact body in advance and remove the mask after the dipping process to avoid locally covering the area with the viscoelastic body. As a third method of formation, it is also possible to carry out the process by insert molding, which is a method in which the contact body is placed in a mold and heated and molten resin material is injected around the contact body to perform integral molding. As a fourth method of formation, the contact body and the viscoelastic body can also be formed by two-color molding (double molding). For example, when considering the application of a resin material to the contact body as the primary molding, PEEK (polyether ether ketone) reinforced by filling it with about 30% carbon fiber can be selected. Alternatively, an elastomer can be applied to the viscoelastic body as the secondary molding. In this case, filling it with carbon fiber can be expected to improve the rigidity of the contact body and the wear resistance and sliding properties of the friction sliding surface. Forming the viscoelastic body by these alternative means not only improves mass production efficiency and allows for the inexpensive formation of viscoelastic bodies, but also enhances the adhesion of the viscoelastic body to the contact body, preventing detachment and displacement of the viscoelastic body. Furthermore, when forming the viscoelastic body using a mold, the relative positions of the elastic body and the contact body can be precisely determined, making it possible to form viscoelastic bodies even with complex shapes.

[0056] In this embodiment, a linear embodiment with the y-direction as the longitudinal direction for the contact body has been described, but the present invention is not limited to a linear contact body. The contact body can have any curved shape, and unwanted vibrations can be suppressed by fitting a viscoelastic body into a curved contact body in the same way. Even when using a curved contact body, it is possible to fix the vibrating body and make the contact body the driven side. In this case, it is preferable to form a contact body support part that matches the shape of the contact body. Conversely, it is also possible to fix the contact body and make the vibrating body the driven side, in which case the vibrating body unit moves relative to the curved contact body. [Examples]

[0057] A second embodiment of the present invention will be described with reference to Figures 7 to 11. As shown in the figures, the Cartesian coordinate system set for each vibration actuator is the same as that of the first embodiment, and the same Cartesian coordinate system will be set for the vibration actuators and actuator units of each embodiment described below. In addition, for components of the vibration actuator that have the same function as those of the first embodiment, the same names and reference numerals will be used, and the description of their common functions and configurations will be omitted.

[0058] Figure 7 is a front view showing a schematic configuration of a vibrating actuator 201 according to the second embodiment. The vibrating actuator 201 comprises two vibrating body units 21 and a contact body 4 that contacts the vibrating body 1 of the vibrating body unit 21.

[0059] Each vibrating unit 21 has two vibrating bodies 1, a nonwoven fabric 16, a pressurizing part 17, and a holding part 8. The end of the pressurizing part 17 is hooked onto a hook 8a provided on the side of the holding part 8, thereby sandwiching and pressing the contact body 4 between one vibrating body 1 and the other vibrating body 1 facing it. Here, an example of a configuration using a tension spring as the pressurizing part 17 is illustrated. Also, similar to the method shown in Figure 4, each holding part 8 is connected to a support member by a connecting part 14, thereby positioning the contact body 4 in the z direction, and each vibrating body 1 and holding part 8 are slidable in the z direction. Here, the projection 2a on the vibrating body 1 plays the role of receiving the reaction force.

[0060] On the other hand, a viscoelastic body 6e is attached to the contact body 4. The y-direction dimension of the viscoelastic body 6e is L5, and a window is provided in the inner section L6 such that the sliding surface of the contact body 4 is exposed. That is, the viscoelastic body 6e is attached so as to be in close contact with two sides of the contact body 4 parallel to the yz plane within the inner region L6, and in the remaining region, it covers the two sides of the contact body parallel to the yz plane and the surface parallel to the xy plane. The region indicated by L5-L6, where the viscoelastic body 6e covers the four surfaces of the elongated prismatic contact body 4, preferably includes the portion corresponding to the antinode of the out-of-plane vibration mode excited by the contact body, as explained in Figure 3.

[0061] Furthermore, similar to the vibrating actuator shown in Figure 4, the contact body unit, consisting of the contact body 4 and the viscoelastic body 6e, is supported by the support member 15 in a state that allows it to move in the y-direction by the thrust received from the vibrating bodies 1 that each vibrating body unit 21 is equipped with. Specifically, four rollers that can rotate about an axis parallel to the z-axis are provided on the support member 15 as contact body support parts 12 that support the contact body unit in a movable manner. The four contact body support parts 12 play the role of linear guides that enable the movement of the contact body unit in the y-direction by constraining the degrees of freedom in the xy-plane of the side surface of the viscoelastic body 6e in the region indicated by L6.

[0062] With the above configuration, the vibrating actuator 201 can reduce components such as the reaction force receiving part 10 and the rotation support part 9 by using a total of four vibrating bodies 1 to support the contact body 4 in the z direction. In addition, by using the vibrating body unit 21 instead of the reaction force receiving part 10 and the rotation support part 9 which do not contribute to thrust, it is possible to increase the thrust of the vibrating actuator. By using four vibrating bodies 1, it is possible to obtain four times the thrust for a common contact body. Furthermore, by covering much of the part of the contact body 4 that is not used for frictional sliding with the viscoelastic material 6e, it is possible to enhance the effect of suppressing unwanted vibrations that occur in the contact body 4, thereby preventing the generation of abnormal noise and performance degradation caused by unwanted vibrations. In summary, according to this embodiment, it is possible to provide a vibrating actuator that can suppress the generation of unwanted vibrations and improve thrust (output) per unit volume or weight.

[0063] Next, the vibration-type actuator 202 according to the second embodiment will be described using Figure 8. Figures 8(a) and 8(b) are a plan view and a front view, respectively, showing the schematic configuration of the vibration-type actuator 202. The vibration-type actuator 202 comprises a vibrating body unit 22 and a contact body 4 that contacts the vibrating body 1 of the vibrating body unit 22, with the contact body 4 fixed to a support member 15, and the vibrating body unit 22 moving relative to the support member 15. Furthermore, the same names and reference numerals will be used for the components of the vibration-type actuator 202 that correspond to the components described above, and explanations of their common functions and configurations will be omitted.

[0064] The vibrating actuator 202 comprises three vibrating units 22 and a contact body 4. Of the three vibrating units, the central and right-hand units are connected by a connecting portion 14. In the vibrating actuator 202, both ends of the contact body 4 are fixed to a support member 15, and three viscoelastic bodies 6g, 6h, and 6i are fitted at the antinodes of out-of-plane vibration modes generated in the contact body 4 at frequencies near the drive frequency applied to the vibrating body 1. In the vibrating unit 22, a spacer 19 with a nonwoven fabric 16 attached is placed inside the holding portion 18. The spacer 19 is provided with a hook 19a, which hooks the end of the pressurizing portion 17, thereby clamping and pressing the contact body 4 between a pair of opposing vibrating bodies 1. In the vibrating unit 22, the two vibrating bodies 1 are supported so as to be slidable in the z direction relative to the holding portion 18, and their degrees of freedom other than in the z direction are constrained by the holding portion 1. Similar to the embodiment described above, the holding portion 18 is provided with an opening 18a, which functions as a linear guide for the vibrating body unit 22 to move in the y direction.

[0065] Of the three vibrating units 22, the left vibrating unit 22 is capable of driving L7 in the y direction between the viscoelastic bodies 6g and 6h. On the other hand, the rightmost and central vibrating units 22 are connected by a connecting part 14 via a holding part, allowing them to slide slightly relative to each other in the z direction. In this case, it is desirable that the connecting part be offset in the x direction so as not to interfere with the contact body 14. The two connected groups of vibrating units 23 are capable of driving L8 in the y direction between the viscoelastic bodies 6h and 6i in sequence.

[0066] With the above configuration, the vibrating actuator 202 allows the vibrating body unit 22 and the group of vibrating body units 23 to move independently in the y-direction. At this time, as shown in Figure 8(a), by providing openings 15b and 15c in the support member 15, the upper surfaces of the vibrating body unit 22 and the group of vibrating body units 23 can be exposed to the outside, and it is possible to connect the object to be driven.

[0067] According to this embodiment, multiple vibrating body units or groups of vibrating body units can be driven independently via a single contact body. In this case, by fitting a viscoelastic body at the antinode position of the out-of-plane vibration mode of the contact body, it is possible to more effectively suppress unwanted vibrations excited by the contact body.

[0068] Furthermore, by connecting two vibrating units to form a group of vibrating units 23, it is possible to generate four times the thrust using a total of four vibrators 1. In this case, by connecting the vibrating units 22 so that they can move slightly relative to each other in the z direction, each vibrating unit follows the deformation of the contact body in the longitudinal direction (in the yz plane), thereby reducing the variation in the pressurized reaction force acting on each vibrating unit. Vibrating units with relatively small pressurized reaction forces experience reduced thrust, while vibrating units with relatively large pressurized reaction forces face risks such as wear due to overload. Therefore, by configuring each group of vibrating units using a connecting part as in this embodiment, each vibrating unit can efficiently generate thrust. In addition, in this embodiment, when the vibrating unit and the group of vibrating units are driven in the y direction and are subjected to overload, the viscoelastic material acts as a buffer, preventing the vibrating unit from being damaged by direct collision with the support member or other vibrating units.

[0069] In this embodiment, a specific method for suppressing unwanted vibrations in the vibration actuator 201 when the contact bodies move relative to each other is described, by attaching a viscoelastic body 6e to the rectangular parallelepiped contact body 4.

[0070] Furthermore, a more advanced embodiment will be described as a contact unit 23 combining the contact body 24 and the viscoelastic body 26 shown in Figure 9. Figure 9 shows the schematic configurations of (a) a plan view of the contact unit 23, (b) a front view of the contact unit 23, (c) a bottom view of the contact unit 23, (d) a plan view of the contact body 24, (e) a front view of the contact body 24, and (f) a bottom view of the contact body 24. For the sake of brevity, in Figure 9, components other than the contact body, viscoelastic body, contact body support part, and vibrating body are not shown, and the pressurized support structure of the vibrating body for the contact body follows the embodiment described above. In Figure 9, the contact unit 23 consists of a contact body 24 and a viscoelastic body 26. The contact body 24 has four sliding parts 24a protruding in the positive and negative z directions, and four guide parts 24b protruding in the positive and negative x directions. On the other hand, the viscoelastic body 26 has a total of eight windows: four windows 26a cut out in the positive and negative z directions, and four windows 26b cut out in the positive and negative x directions. In Figure 9, the sliding part 24a of the contact body is mounted so that it protrudes from the windows 26a of the viscoelastic body, and the guide part 24b of the contact body protrudes from the windows 26b of the viscoelastic body. The sliding part 24a functions as a friction sliding surface that presses against the projection 2a of the vibrating body 1 and generates the frictional force necessary for driving, and the guide part 24b functions as a linear guide for guiding the contact body in the y direction using four contact body support parts 12.

[0071] Applying the contact unit 23 to a vibratory actuator can be expected to yield the following benefits. First, by closely attaching the viscoelastic body 26 to the sides of the contact body 24 other than the sliding part and the guide part, a higher level of unwanted vibration suppression can be expected. Furthermore, by limiting the sliding part 24a to the necessary area, it is possible to reduce the cost of grinding (polishing) to obtain stable friction sliding characteristics. In addition, because the sliding part 24a protrudes outward from the viscoelastic body 26, grinding (polishing) of the sliding part 24a can be easily performed even when the vibratory unit 23 has the viscoelastic body 26 attached. On the other hand, by making the guide part 24b protrude outward from the viscoelastic body 26, rolling resistance can be reduced compared to when the contact support part 12 rotates on the viscoelastic body, thereby reducing losses in the vibratory actuator. In addition, when an external force is applied to the contact body 4, the amount of displacement of the contact body can be suppressed compared to when the contact support part 12 directly supports the viscoelastic body 26. In other words, in a vibratory actuator, it is possible to construct a highly rigid linear guide even when the contacting bodies move relative to each other.

[0072] In this embodiment, a configuration for improving output per unit volume or weight using multiple vibrating bodies has been described. Next, various configurations in which a single vibrating body unit comprises multiple vibrating bodies and supports each vibrating body by contacting its protrusions to a contact body will be described as configurations that can be applied to the vibrating actuator according to the above embodiments. Figures 10(a) to (f) are schematic diagrams illustrating the support structure of a contact body by multiple vibrating bodies, and are simply shown from the y-direction, which is the direction of movement of the contact body. Note that the coordinate axes are shown only in Figure 10(f) and are omitted in Figures 10(a) to (e). In addition, the nonwoven fabric, spacer, pressurizing part, and holding part for the vibrating body are not shown in Figures 10(a) to (f), but those described in each embodiment above can be appropriately selected and used.

[0073] Figure 10(a) shows a configuration in which two opposing vibrators 1 support a contact body 4, a configuration used, for example, in a vibrating actuator 201 (see Figure 7). Figure 10(b) shows a configuration in which vibrators 1 are placed on each of the four sides of a contact body 74 having a rectangular cross-section to support the contact body 74. Figure 10(c) shows a configuration in which the substantially cylindrical side surface (curved surface) of a contact body 75 having a substantially circular cross-section is supported by three vibrators 1 arranged at approximately 120° intervals in the zx plane.

[0074] Figure 10(d) shows a configuration in which a contact body 76 having a polygonal cross-section is supported by placing vibrators 1 on three of its sides. Figure 10(e) shows a configuration in which three of the sides of a contact body 77 having a polygonal cross-section are supported by vibrators 1 and 81 of different sizes and thrusts. Figure 10(f) shows a configuration in which a substantially cylindrical side of a contact body 75 having a substantially circular cross-section is supported by two vibrators 1 and two reaction force receiving parts 10. By selecting and using these configurations, contact bodies having various cross-sectional shapes can be appropriately supported by vibrators. Even in the configurations of vibrators and contact bodies exemplified in Figure 10, unwanted vibrations can be reduced by applying the various embodiments of viscoelastic materials described above.

[0075] Next, we will describe an example configuration in which a displacement detection means is provided on the vibrating unit constituting each of the above embodiments of the vibration-type actuator. Figure 11 is a front view showing the state in which the displacement detection unit 84 is attached to the vibrating unit 22. Here, we will use the vibrating unit 22 as an example, but the displacement detection unit 84 can also be mounted on other vibrating units.

[0076] The displacement detection unit 84 includes a scale 82 and a detector 83. The scale 82 is mounted on the contact support part 12 provided on the holding part 18 in a position that does not physically interfere with (contact with) the contact body 4 (not shown in Figure 11). The scale 82 rotates together with the roller-shaped contact support part 12 in accordance with the displacement of the contact body 4. The detector 83 detects the amount of movement of the contact body 4 in the y-direction by reading the rotational displacement of the scale 82. The rotational displacement of the scale 82 can be read by irradiating the scale 82 with light from the light source part of the detector 83 and receiving the reflected light with the light receiving part of the detector 83. Based on the amount of movement of the contact body 4 in the y-direction output by the detector 83, drive parameters such as the position, velocity, and acceleration of the contact body 4 can be controlled.

[0077] Furthermore, various types of displacement detection units 84 can be used, such as optical, magnetic, or capacitive types. Here, an optical, reflective type displacement detection unit 84 has been described, but a transmissive type can also be used in the case of an optical type. Moreover, instead of a rotary type displacement detection unit 84, a linear type displacement detection unit may be adopted in which a linear type scale is placed on the contact body 4 and a detector is placed on the vibrating body unit. [Examples]

[0078] Figure 12 is a diagram illustrating the schematic configuration of the actuator unit 401 according to the third embodiment. Figures 12(a) to (d) are a plan view (top view), a side view, a front view, and a perspective view of the actuator unit 401, respectively. Note that the same names and reference numerals are used for the components of the actuator unit 401 that correspond to the components of each of the vibration-type actuators described above, and explanations of their common functions and configurations are omitted.

[0079] The actuator unit 401 is a package of the vibrating actuator 201 using an exterior member 86. In other words, in the actuator unit 401, the support member 15 of the vibrating actuator 201 is movably fixed to the inner bottom surface of the exterior member 86. The contact body 4 moves in the y direction while penetrating the end face (zx surface) of the exterior member 86, thereby extracting power from the contact body 4. Therefore, in the actuator unit 401, the contact body 4 and a portion of the viscoelastic body 6e of the vibrating actuator 201 are exposed from the exterior member 86. The vibrating body unit 21 and other components that are covered and invisible by the exterior member 86 are shown by dashed lines in Figure 12(c).

[0080] In this way, by packaging the vibrating actuator 201 with an exterior member 86 to form an actuator unit 401, the user can safely handle the unit by gripping the exterior member 86, and the vibrating actuator 201 can be protected. Although an example of packaging the vibrating actuator 201 is shown here, the vibrating actuators according to each of the above embodiments can all be unitized using the exterior member 86 without exception. The exterior member 86 may be integrally configured with a support member 15 or the like. [Examples]

[0081] In the following embodiments, we will describe application examples of the various vibration-type actuators described above, that is, various devices (equipment) equipped with vibration-type actuators.

[0082] Figure 13 is a plan view showing the schematic configuration of the device 501 according to the fourth embodiment. The device 501 comprises six vibrating actuators 102 and a support member 35. The six vibrating actuators 102 are fixed to the support member 35 via the support member 15, with the support member 15 as the reference position. The support member 35 corresponds to an enlarged version of the support member 15 in the xy plane and is formed as a single member.

[0083] As in the device 501, it is easy to arrange six vibrating actuators 102 in a plane. For example, six vibrating actuators 102 can be easily arranged in a plane such that they are spaced d in the y direction from the reference position J of the support member 35, and the distance between adjacent support members 15 in the x direction is distance e. In this case, the distance between the contact bodies 4 of adjacent vibrating actuators 102 in the x direction can all be the same distance f. Each vibrating unit 11 of the six vibrating actuators 102 may be connected to one drive component (load) or to different drive components (loads).

[0084] It goes without saying that, although the device 501 is configured here with six vibrating actuators 102, a similar device can be configured using any number of vibrating actuators 102. Furthermore, depending on the configuration of the device, the multiple vibrating actuators can be arranged at any position on the same plane or on different planes.

[0085] As described above, the vibration actuator 102 in the present invention allows for the narrowest possible width dimension of the contact body 4 in the x-direction and suppression of unwanted vibrations by a viscoelastic material. Therefore, when multiple vibration actuators are used in a row in the x-direction, as in the device 501, the device can be miniaturized. Furthermore, as shown in Figure 13, further miniaturization is possible by arranging the vibration actuators 102 so that they are in contact with each other. Moreover, by forming the support member 15 and support member 35 constituting the vibration actuator 102 as a single integrated part and minimizing the x-direction dimension of the support member as much as possible within the range where the vibration unit 11 does not interfere, significant miniaturization is possible. [Examples]

[0086] Figure 14(a) is a plan view showing the schematic configuration of the drive unit 500 according to the fifth embodiment. Figure 14(b) is a side view showing the schematic configuration of the vibrating actuator 201 that constitutes the drive unit 500. The drive unit 500 integrally comprises 12 vibrating actuators 201 (see Figure 7) and a support member 36. The support member 36 is formed by 12 support members 15 for the 12 vibrating actuators 201 as a single columnar member such that the cross section perpendicular to the y-direction, with the y-direction as the axial direction, forms a substantially regular dodecagon centered at point K. Each of the 12 vibrating actuators 201 is fixed radially to 12 sides (planes parallel to the y-axis) of the zx cross section of the support member 36, via the support member 15, and with the support member 15 as the reference position, corresponding to each side of the substantially regular dodecagon. In this way, the drive unit 500 can accurately arrange multiple contact bodies 4 on the circumference of a pitch circle 37 with a diameter g centered at point K when viewed from the y-direction. Similar to Example 4, by setting the width dimension of the contact body 4 to be as narrow as possible and suppressing unwanted vibrations with a viscoelastic material, it is possible to set the diameter g to be small and miniaturize the drive unit 500. Furthermore, by forming the support members 15 and 36 that constitute the vibrating actuator 102 as a single integrated part, significant miniaturization is possible.

[0087] In the drive unit 500, vibrating actuators 201 are placed on all sides of the support member 36, but the vibrating actuators 201 can be placed at any position on any side. Also, the support member 36 is not limited to a dodecagonal prism and can be changed to any polygonal prism. [Examples]

[0088] Figure 15 is a plan view showing the schematic configuration of a multi-axis stage 503 according to the sixth embodiment. The multi-axis stage 503 comprises a fixed part 41, an x-stage 42, a y-stage 43, and an xy-stage 44.

[0089] The fixed part 41 is immobile, with its degrees of freedom constrained in all directions. In the same manner as the device 501 described with reference to Figure 13, four actuator units 401 (see Figure 12) are arranged in the y-direction and fixed to the fixed part 41. The four contact bodies 4 of the four actuator units 401 fixed to the fixed part 41 are movable in the x-direction in Figure 15, and the right end of each is fixed to the x-stage 42.

[0090] The x-stage 42 is movable only in the x-direction, with its degrees of freedom constrained in other directions, and is driven in the x-direction by four actuator units 401 fixed to the fixed part 41. Two actuator units 401 are fixed to the x-stage 42 side by side in the x-direction. The two contact bodies 4 of the two actuator units 401 fixed to the x-stage 42 are movable in the y-direction in Figure 15, and their upper ends are fixed to the y-stage 43.

[0091] The y-stage 43 is movable only in the y-direction, with its degrees of freedom in other directions constrained, and is driven in the y-direction by two actuator units 401 fixed to the x-stage 42. The xy-stage 44 is fixed to the y-stage 43. The xy-stage 44 moves in the xy-plane in conjunction with the movement of the x-stage 42 and / or the y-stage 43.

[0092] The mass moved by the actuator unit 401 provided on the fixed section 41 is greater than the mass moved by the actuator unit 401 provided on the x-stage 42. Taking this into consideration, the number of actuator units 401 placed on the fixed section 41 and the x-stage 42 should be set according to the mass of the object to be moved. The multi-axis stage 503 is configured as an xy stage with two degrees of freedom, but a stage with any degree of freedom can be realized by using multiple actuator units 401.

[0093] In the multi-axis stage 503, the drive target is moved in a predetermined direction by multiple actuator units 401, thus suppressing the generation of moments in a plane parallel to the xy plane. As a result, the xy stage 44 can be moved with high precision within the xy plane.

[0094] Similarly in this embodiment, by setting the width dimension of the contact body 4 in the x-direction to be as narrow as possible and suppressing unwanted vibrations with a viscoelastic material, it is possible to miniaturize the stages 41 and 42. [Examples]

[0095] Figure 16 is a plan view showing the schematic configuration of the articulated robot 505 according to the seventh embodiment. The articulated robot 505 is an example of an articulated robot employing an antagonistic drive system. The articulated robot 505 includes a first joint 52, a fixed part 54, a first pulley 55, a first link 56, a second link 57, a second joint 58, a second pulley 59, a third pulley 60, a wire 51e, and a wire 53e. In the following description, the actuator units 401 provided on the fixed part 54 will be assigned the reference numerals E1, F1, E2, and F2 respectively to distinguish them.

[0096] The first joint 52 has a degree of rotational freedom that allows it to rotate around an axis parallel to the z-axis centered at point L. The second joint 58 has a degree of rotational freedom that allows it to rotate around an axis parallel to the z-axis centered at point M and is constrained by the movement of the first link 56. The first pulley 55, shown by the dashed line, is constrained by the first link 56 and is rotatable around the first joint 52. The second link 57 is rotatable around the second joint 58 via the second joint 58. The second pulley 59 is constrained by the second link 57. The third pulley 60 is rotatable around the first joint 52.

[0097] Wire 51e is wound around the first pulley 55, with one end connected to the contact body 4 of actuator unit F1 and the other end connected to the contact body 4 of actuator unit E1. Wire 53e is wound around the third pulley 60, with one end connected to the contact body 4 of actuator unit F2 and the other end connected to the contact body 4 of actuator unit E2. Wire 53a is formed in an endless (loop) shape and is installed between the second pulley 59 and the third pulley 60.

[0098] The actuator units E1 and F1, positioned such that the direction of movement of the contact body 4 is the y-direction in Figure 16, each drive the wire 51e in the y-direction. When the actuator units E1 and F1 generate thrust in the y-direction to prevent the wire 51e from slackening, a frictional force is generated between the wire 51e and the first pulley 55 due to the difference in the generated thrust, causing the first link 56 to rotate around the first joint. As a result, the actuator units E1 and F1 can cause the first link 56 to undergo a displacement of angle θ1 with respect to the x-axis.

[0099] Similarly, actuator units E2 and F2, in which the contact body 4 is positioned to be movable in the x-direction in Figure 16, each drive the wire 53e in the x-direction. When the vibrating actuators E2 and F2 generate thrust in the x-axis direction to prevent the wire 53e from slackening, a frictional force is generated between the wire 53e and the third pulley 60 due to the difference in the generated thrust. This frictional force causes the third pulley 60 to rotate, and the second pulley 59 is linked via the endless wire 53a, driving the first link 56 and the second link 57 around the first joint 52 and the second joint 58. In other words, actuator units E2 and F2 can cause a displacement of angle θ1 with respect to the x-axis in Figure 16 in the first link 56, and a displacement of angle θ2 with respect to the first link 56 in the second link 57. Furthermore, by driving actuator units E1 and F1 in such a way as to counteract the displacement of the first link 56 by angle θ1 caused by the driving of actuator units E2 and F2, it is possible to generate only a displacement of the second link 57 by angle θ2.

[0100] In this way, the articulated robot 505 can move the tip N of the second link 57 to a target position in the xy plane by driving multiple actuator units 401. Furthermore, by maintaining constant tension on the wires 51e and 53e to prevent slack and driving them in opposition, it is possible to suppress rattle around the joints and deviations caused by buckling of the wires 51e and 53e. As a result, the torsional rigidity around each joint can be increased, and the tip N can be positioned with high precision.

[0101] Similarly in this embodiment, by setting the width dimension of the contact body 4 in the x-direction to be as narrow as possible and suppressing unwanted vibrations with a viscoelastic material, it is possible to miniaturize the fixing part 54. [Examples]

[0102] Figure 17 is a plan view showing the schematic configuration of the continuum robot 506 according to the eighth embodiment. While the articulated robot 505 according to the seventh embodiment operates in an antagonistic drive system, the continuum robot 506 operates in a drive system that pushes and pulls the wire within a thrust range that does not cause the wire to buckle.

[0103] The continuous robot 506 comprises a base 502 and a wire-driven manipulator 504. Figure 18 is a perspective view showing the schematic configuration of the wire-driven manipulator 504. The wire-driven manipulator 504 is equivalent to, for example, the one described in Japanese Patent Application Publication No. 2018-140101. The wire-driven manipulator 504 has an intermediate section 61 and two curved sections 66a and 66b. The linear member 62 can change the curvature of the curved sections 66a and 66b by sliding the hollow section of the guide tube 65 provided in the intermediate section 61 without buckling. The intermediate section 61 may be made of a flexible material, as shown in Figure 17.

[0104] In the wire-driven manipulator 504, three linear members 62 are provided for each curved section. Specifically, the tips of three of the six linear members 62 are fixed to the guide member tip member 63a, and one is fixed to the guide member 64a. The curvature of the curved section 66a is changed by driving the other two linear members. Similarly, the tips of the remaining three linear members 62 are fixed to the tip member 63b, and one of these linear members is fixed to the guide member 64b. The curvature of the curved section 66b is changed by driving the other two linear members.

[0105] In the continuous robot 506, a drive unit 500 is mounted on the base 502 as the drive source for the wire-driven manipulator 504 (see Figure 14). The contact bodies 4 of the vibratory actuator 201 housed in the base 502 are each coupled to the linear members 62 and are used as drive sources to change the curvature of the curved sections 66a and 66b of the wire-driven manipulator 504, respectively. It is desirable that the base 502 be packaged using an exterior member, similar to the configuration described with reference to Figure 12, which allows for proper protection of internal components and improves operability.

[0106] In the continuous robot 506, the wire-driven manipulator 504 is driven by a drive unit 500 mounted on the base unit 502, allowing for high-precision control of the curvature of the curved sections 66a and 66b. Furthermore, by using the base unit 502 as the drive unit for the wire-driven manipulator 504, the drive unit can be made smaller and lighter, improving operability. In addition, by increasing or decreasing the number of vibrating units in the base unit 502, the required output for the curved sections 66a and 66b can be easily accommodated. Moreover, by using a direct-drive type vibrating actuator to drive the linear member 62 of the wire-driven manipulator 504, responsiveness can be improved compared to using a drive means that combines an electromagnetic motor and a reduction mechanism.

[0107] Multiple vibrating actuators 201 housed in the base 502 allow for easy modification of the output from each vibrating actuator 201 by increasing or decreasing the number of vibrating units 20. Furthermore, by changing the amplitude ratio of the vibrations of the multiple vibration modes excited by the vibrating body 1, the magnitude of the thrust and the driving speed for driving (bending) the curved sections 66a and 66b can also be controlled. When no voltage is applied to the electromechanical energy conversion element 3, the static friction force acting between the projection 2a and the contact body 4 can maintain the posture of the curved sections 66a and 66b.

[0108] Furthermore, by driving the vibrating body 1 using only the second vibration mode (Figure 2(b)), the frictional force acting between the projection 2a and the contact body 4 can be changed, so that when an external force acts on the curved parts 66a and 66b, the posture of the curved parts 66a and 66b changes according to that external force. This function can be used, for example, as a safety mechanism when using a continuous body robot for medical applications. In this way, when driving the vibrating body 1 using only the second vibration mode (Figure 2(b)) and significantly reducing the frictional force between the vibrating body 1 and the contact body 4, it is necessary to set a large vibration amplitude. Generally, the larger the vibration amplitude, the larger the vibration amplitude of unwanted vibrations becomes, leading to a decrease in output and the generation of loud abnormal noises. As explained in the above embodiment, by fitting a viscoelastic material into the contact body, it is possible to suppress unwanted vibrations without increasing the size of the vibrating actuator. Therefore, such a safety mechanism can be realized by using the vibrating actuator of the present invention.

[0109] The continuous robot 506 can be applied to, for example, industrial endoscopes, medical endoscopes, and surgical instruments such as catheters used in medical procedures such as treatment, biopsy, and examination. The continuous robot 506 has a 4-degree-of-freedom configuration with two bending sections 66a and 66b, but the number of bending sections, i.e., the degrees of freedom, can be set arbitrarily. 66b is the distal bending section, and 66a is the follow-up bending section.

[0110] In this case, the shape of the support member 36, the diameter g of the pitch circle 37, and the number and arrangement of the vibrating actuators 201 should be set to appropriate conditions relative to the base 502, depending on the number of curved sections and the diameter of the guide members.

[0111] For example, the object connected to the vibrating unit by the connecting part was a different vibrating unit or support member in the above embodiment, but is not limited to these; any part or component that can move relative to the contact body is acceptable. Furthermore, while the multi-axis stage 503 and articulated robots 505 and 506 were given as examples of devices to which the vibrating actuator and actuator unit according to each embodiment above can be applied, examples of applicable devices are not limited to these. For example, other examples of devices according to the present invention include various stage devices such as microscopes, machine tools, and measuring devices, as well as vertical articulated robots and parallel link type robots that have more degrees of freedom than the articulated robot 505.

[0112] Although the present invention has been described in detail above based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various electronic devices that do not depart from the spirit of the invention are also included in the present invention. Furthermore, each of the embodiments described above is merely one embodiment of the present invention, and it is possible to combine each embodiment as appropriate. [Explanation of symbols]

[0113] 1. Vibrating body 4 Contact body 6,6a~6i,26 Viscoelastic material 5,11,21,22 Vibrating Unit 23 Contact Unit 7,13,17 Pressurized section 8,18 Holding part 9. Reaction force receiving section 12 Contact body support part 14 Connection part 15, 35, 36 Support members 86 Exterior components 101, 102, 201, 202 Vibration-type actuators 401 Actuator Unit 501,502 equipment 503 Multi-axis stage 505 Articulated Robot 506 Continuum Robot

Claims

1. A vibrating body including an elastic body and an electromechanical energy conversion element, The system comprises a contact body that is elongated in a predetermined direction and in contact with the vibrating body, A vibrating actuator configured such that the vibrating body and the contact body move relative to each other in a predetermined direction due to the vibration of the vibrating body, The end of the contact body is covered with a viscoelastic material in the circumferential direction with respect to the predetermined direction. The viscoelastic body has a first notched window portion, and the vibrating body and the contact body are in contact through the first window portion, characterized in that the viscoelastic body has a first notched window portion, and the vibrating body and the contact body are in contact through the first window portion.

2. The vibration-type actuator according to claim 1, characterized in that the total length of the viscoelastic body in the predetermined direction is half a wavelength or more of the vibration wave in the natural vibration mode accompanied by out-of-plane vibration excited to the contact body in conjunction with the vibration of the vibrating body.

3. The natural vibration mode excited by the vibrating body is an out-of-plane bending vibration mode that generates a plurality of nodal lines in the predetermined direction, The vibration actuator according to claim 1 or 2, characterized in that the sum of the lengths of the viscoelastic material in the predetermined direction is equal to or greater than the distance between adjacent nodal lines.

4. The elastic body has a plurality of protrusions, The vibration-type actuator according to any one of claims 1 to 3, characterized in that the sum of the lengths of the viscoelastic body in the predetermined direction is equal to or greater than the distance between the centers of adjacent plurality of protrusions.

5. The vibration-type actuator according to any one of claims 1 to 4, characterized in that the viscoelastic body is located at both ends of the elongated contact body.

6. The vibration actuator according to any one of claims 1 to 5, characterized in that the viscoelastic body is provided at a position including an antinode in a natural vibration mode accompanied by out-of-plane vibration excited to the contact body when the viscoelastic body is not provided to the contact body.

7. The viscoelastic material is a member having hollow pores, When the viscoelastic body is not attached to the contact body, the inner circumference of the hole in the viscoelastic body is The vibration actuator according to any one of claims 1 to 6, characterized in that the sum of the lengths around the contact body in a cross-section perpendicular to the predetermined direction is smaller than the sum of the lengths around the contact body.

8. The vibrating actuator includes a contact support portion that supports the contact body so that it can move in the predetermined direction, The vibration actuator according to any one of claims 1 to 7, characterized in that the viscoelastic body has a second window portion which is cut out so as to expose a guide portion into which the contact body and the contact body support portion come into contact.

9. The vibration actuator according to claim 8, characterized in that the guide portion is in contact with the contact body via the second window portion.

10. Further equipped with a holding part, The vibrator is held by the holding part, The vibrating actuator according to any one of claims 1 to 9, characterized in that, in a cross-section of the vibrating actuator perpendicular to the predetermined direction, the width dimension of the viscoelastic body is smaller than the width dimension of the vibrating body or the width dimension of the holding portion.

11. The vibration actuator according to any one of claims 1 to 10, comprising a plurality of vibrating bodies, wherein the vibrating bodies are moved relative to a common contact body to which the viscoelastic body is attached in a predetermined direction.

12. The vibration-type actuator according to any one of claims 1 to 11, characterized in that the viscoelastic body is formed from a rubber material.

13. The vibration-type actuator according to any one of claims 1 to 12, characterized in that an endless viscoelastic body covering the side surface of the contact body is attached to a part of the contact body.

14. The vibration actuator according to claim 13, characterized in that the viscoelastic body has a window portion cut out so that a part of the contact body is exposed.

15. The vibration actuator according to claim 14, characterized in that a part of the contact body protrudes from the window portion.

16. A vibrating actuator according to any one of claims 1 to 15, It has an exterior member that houses a part of the aforementioned vibrating actuator inside, An actuator unit in which a portion of the contact body of the vibrating actuator is exposed to the outside of the exterior member.

17. A vibrating actuator according to any one of claims 1 to 15, A component driven by the aforementioned vibrating actuator, An electronic device characterized by having the following features.

18. The electronic device according to claim 17, wherein a plurality of the vibration-type actuators are arranged radially in a cross section perpendicular to the predetermined direction.

19. A vibrating actuator according to any one of claims 1 to 15, The fixing part to which the vibrating actuator is fixed, A multi-axis stage characterized by comprising a stage connected to the contact body and moving relative to the fixed part in a predetermined direction.

20. A multi-joint robot characterized by being equipped with a vibrating actuator as described in any one of claims 1 to 15 as a drive source.

21. Wire-driven manipulator and A continuous robot characterized by comprising a vibrating actuator according to any one of claims 1 to 15 as a drive source for the wire-driven manipulator.

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