JP7451211B2 - Contact body, vibration type actuator having the same, method for manufacturing the contact body, and method for deriving the amount of polishing in the contact body - Google Patents

Description

The present invention relates to a contact body, a vibration type actuator having the same, a method for manufacturing the contact body, and a method for deriving the amount of polishing in the contact body.

The vibrating body and the contacting body come into contact, exciting (generating) a predetermined vibration in the vibrating body, and applying frictional driving force from the vibrating body to the contacting body, so that the contacting body moves relative to the vibrating body. (hereinafter also referred to as "relative movement") vibration type actuators are known. In a vibration type actuator, an electro-mechanical energy conversion element such as a piezoelectric element is bonded to the vibrating body, and vibration is generated in the vibrating body by applying an alternating current voltage to the electro-mechanical energy conversion element.

Such a vibration type actuator is characterized by a large holding force because it utilizes the frictional force generated due to contact. Therefore, even if an external force acts in a non-energized state, the positional relationship between the vibrating body and the contact body can be maintained (the vibrating body and the contact body can be stopped at that position).

Patent Document 1 describes a friction material in which a stainless steel sintered valley is impregnated with a resin mixed with hard particles, as a contact body used in such a vibration type actuator. In this friction material, the impregnated resin acts as a sliding material, contributing to improving wear resistance and maintaining a high coefficient of friction. In addition, the hard particles exhibit a spike effect and maintain a high coefficient of friction even after being placed in high temperature and high humidity conditions, so good results can be expected.

Patent Document 2 describes the shape of a stainless steel sintered body for impregnating a resin in a desired state when manufacturing a contact body.

JP 2017-225333 Publication JP2019-017238A

In the case of the friction material (contact body) described in Patent Documents 1 and 2, in order to maintain the holding force, the resin is impregnated into the pores on the friction surface (contact surface) that contacts the vibrating body at an appropriate ratio. It is important to maintain stable frictional force.

In the process of manufacturing the contact body, resin remains on the friction surface of the sintered body coated with resin, so the cured resin is removed and the resin-impregnated part where the sintered body is impregnated with resin is removed. I need to get it out. Furthermore, in order to drive the vibrating body well, it is necessary to improve the flatness and parallelism of the friction surface. For this reason, double-sided polishing, in which both sides are polished at the same time, and double-sided grinding, in which both sides are simultaneously ground, are performed.

At that time, as the amount of polishing, which is the thickness removed by polishing, and the amount of grinding, which is the thickness removed by grinding, of the plane containing the surface of the resin-impregnated part (hereinafter referred to as "first plane") increases. , the ratio of resin to the surface area (surface resin ratio) decreases, and the holding power decreases.

Therefore, in order to obtain a constant holding force, it is necessary to obtain a constant surface resin percentage. To this end, it is effective to reduce the amount of polishing or grinding of the first plane. To achieve this, it is effective to increase the area ratio (area of the first plane/area of the second plane, which is the plane on the back side of the first plane) and to lower the surface pressure on the first plane side. be.

However, in double-sided polishing, large variations occur in the polishing amount ratio (amount of polishing on the first plane/amount of polishing on the second plane) for each polishing lot depending on the state of deterioration of the free abrasive grains used. Also, in double-sided grinding, large variations occur in the grinding amount ratio (grinding amount of the first plane/grinding amount of the second plane) for each grinding lot depending on the deterioration state of the free abrasive grains used. Therefore, it is difficult to obtain a constant surface resin ratio. Further, in order to select contact bodies having a constant surface resin ratio, it is difficult to accurately determine the amount of polishing or grinding of the first plane from the thickness of the sintered body. This is because, as described above, large variations occur in the polishing amount ratio for each polishing lot and the grinding amount ratio for each grinding lot.

If the sintered body has a chamfered part and a flat part as in Patent Document 2, the amount of polishing and grinding can be determined by determining the polished surface or the difference between the level difference between the ground surface and the flat part. There are ways to do this. However, after sintering, burrs are irregularly generated at the edges of the flat portion, and the area of the flat portion is also small. Therefore, in contact-type measurements, the measuring stylus comes into contact with the burr, making it difficult to perform simple and highly accurate measurements.

Therefore, it has not been possible to easily and accurately inspect whether or not the contact body has undergone a predetermined amount of polishing or less than the amount of grinding (a predetermined surface resin ratio or more) after the contact body has been processed.

The present invention provides a contact body having a resin-impregnated part in which a sintered body is impregnated with resin, and which allows easy determination of the amount of polishing and grinding of a plane including the surface of the resin-impregnated part. The purpose is to Note that, hereinafter, "polishing" is also used as a generic term for "polishing" and "grinding."

The contact body according to the present invention is a contact body that contacts a vibrating body that generates vibration and moves relative to the vibrating body in a vibration type actuator,
a resin-impregnated part in which a sintered body is impregnated with resin, and a recess formed in the sintered body,
It is characterized in that the opening surface of the recess is formed in a plane that includes the surface of the resin-impregnated portion.

As described above, according to the present invention, the contact body has a resin-impregnated portion in which a sintered body is impregnated with resin, and it is possible to easily derive the polishing amount and grinding amount of a plane including the surface of the resin-impregnated portion. A possible contact body etc. can be provided.

FIG. 3 is a diagram illustrating a method for manufacturing a friction material (contact body) of the present invention. FIG. 1 is a diagram showing a vibration type actuator of the present invention. A diagram showing vibration modes in a vibrating body. A plan view and a sectional view of a contact body according to a second embodiment. A plan view and a sectional view of a contact body according to a third embodiment. 1 is a diagram showing a schematic configuration of an imaging device such as a camera including a vibration type actuator of the present invention. FIG. 1 is a perspective view showing a schematic configuration of a robot equipped with a vibration type actuator of the present invention.

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

FIG. 2 is a diagram illustrating a schematic configuration of the vibration type actuator 1. The vibration type actuator 1 includes a vibrating body 2 and a contact body 6 that comes into contact with the vibrating body 2. The vibrating body 2 includes a flat elastic body 3, a piezoelectric element 4 which is an electro-mechanical energy conversion element bonded to one surface of the elastic body 3, and two piezoelectric elements provided on the other surface of the elastic body 3. It has a protrusion 5.

A "contact body" refers to a member that comes into contact with a vibrating body and moves relative to the vibrating body due to vibrations generated in the vibrating body. The contact between the contact body and the vibrating body is not limited to direct contact in which no other member is interposed between the contact body and the vibrating body. If the contact body moves relative to the vibrating body due to vibrations generated in the vibrating body, the contact between the contact body and the vibrating body is an indirect contact in which another member is interposed between the contact body and the vibrating body. Good too. "Other members" are not limited to members independent of the contact body and the vibrating body (for example, a high friction material made of a sintered body). The "other member" may be a surface-treated portion formed on the contact body or the vibrating body by plating, nitriding, or the like.

FIG. 3A is a simplified perspective view of the vibrating body 2. FIG. For example, the piezoelectric element 4 has a common electrode (not shown) formed on the surface on the elastic body 3 side, and a common electrode (not shown) on the surface opposite to the surface on the elastic body 3 side, which is divided into two equal parts in the length direction. It has a structure in which the illustrated drive electrodes are formed.

FIG. 3(b) is a diagram illustrating the first vibration mode (hereinafter referred to as "A mode") of the two bending vibration modes excited in the vibrating body 2. The A mode is a second-order bending vibration in the longitudinal direction (X direction) of the vibrating body 2, and has three nodal lines substantially parallel to the transverse direction (Y direction (width direction)) of the vibrating body 2. ing. By applying an alternating voltage with a predetermined frequency and a phase shift of 180° to the drive electrode of the piezoelectric element 4, A-mode vibration can be excited in the vibrating body 2. The protrusion 5 is disposed near a node in the A-mode vibration, and performs reciprocating motion in the X direction when the A-mode vibration is excited in the vibrating body 2.

FIG. 3(c) is a diagram illustrating the second vibration mode (hereinafter referred to as "B mode") of the two bending vibration modes excited in the vibrating body 2. The B mode is first-order bending vibration in the transverse direction (Y direction) of the vibrating body 2, and has two nodal lines substantially parallel to the longitudinal direction (X direction). By applying an alternating voltage of a predetermined frequency and the same phase to the drive electrode of the piezoelectric element 4, B-mode vibration can be excited in the vibrating body 2. The protrusion 5 is arranged near the antinode position of the B-mode vibration, and when the B-mode vibration is excited in the vibrating body 2, the protrusion 5 performs reciprocating motion in the axial direction (Z direction). conduct.

The vibrating body 2 is configured such that the nodal line in the A mode and the nodal line in the B mode are substantially perpendicular to each other in the XY plane. Furthermore, a flexible substrate (not shown) is bonded to the piezoelectric element 4, and by supplying alternating current to the piezoelectric element 4 through the flexible substrate, it is possible to simultaneously excite A-mode and B-mode vibrations in the vibrating body 2. can. Therefore, by exciting the A-mode and B-mode vibrations with a predetermined phase difference, it is possible to generate elliptical motion in the ZX plane at the tip of the protrusion 5.

In the vibration type actuator 1, the three vibrating bodies 2 are arranged such that the protrusion 5 and the contact surface 6c of the contact body 6 are in contact with each other. Therefore, when the contact body 6 is rotatably supported in the direction of rotation shown by the arrow in FIG. and rotate in its circumferential direction. In addition, in FIG. 2, illustrations of a support member that rotatably supports the contact body 6, a holding member that holds the vibrating body 2, a pressurizing means for bringing the vibrating body 2 and the contact body 6 into contact, etc. are omitted. ing. In this embodiment, the vibrating body 2 is fixed and the contact body 6 is rotatable, but conversely, the contact body 6 may be fixed and the three vibrating bodies 2 are rotatable together with the holding member.

FIG. 1 is a diagram illustrating a method for manufacturing the contact body 6 of FIG. 2 using a radial cross section of the contact body 6. As shown in FIG. The left side of FIG. 1 is the inner diameter side of the annular contact body 6, and the right side of FIG. 1 is the outer diameter side of the contact body 6. In this embodiment, the contact body 6 uses a martensitic stainless steel sintered body equivalent to SUS420J2 as the sintered body 6a (FIG. 1(a)). The cross-sectional shape of the sintered body is approximately rectangular with chamfered corners. The chamfered portion (chamfered portion) is provided when molding the stainless steel powder. In order to suppress the occurrence of burrs at the corners, the chamfered portions are provided with flat portions. Further, the surface of the contact body 6 that comes into contact with the vibrating body 2 is composed of a surface that comes into contact with the vibrating body 2 (contact surface 6c) and a surface that does not come into contact with the vibrating body 2 (non-contact surface 6d). . The width of the contact surface 6c is determined in consideration of dimensional tolerances of the sintered body 6a, assembly errors, etc.

Note that the "surface that comes into contact with the vibrating body" refers to a surface that has a portion that comes into contact with the vibrating body in a vibrating actuator that has a vibrating body and a contact body. However, since a single contact body does not have a vibrating body as a component, it is a surface having a portion that may come into contact with a vibrating body. In addition, the "surface that does not come into contact with the vibrating body" does not refer to a vibrating actuator that has a vibrating body and a contact body, but rather a contact body alone does not actually come into contact with the vibrating body, so it does not come into contact with the vibrating body. It refers to an aspect that has no possibility.

The contact surface 6c and the non-contact surface 6d are on the same plane.

A recess 6b is provided between the contact surface 6c and the non-contact surface 6d, and the contact surface 6c and the non-contact surface 6d are discontinuous. The width of the recess 6b decreases at a constant rate as the depth of the recess 6b increases. That is, the shape of the recess 6b in the radial cross section of the contact body 6 is a V-groove shape. Further, the recess 6b is provided in an annular shape along the shape of the annular contact body 6. The angle θ1 between the contact surface 6c and the slope on the contact surface side of the recess 6b is larger than the angle θ2 between the slope surface adjacent to the contact surface 6c and opposite to the slope on the contact surface side of the recess 6b. do. Further, the angle θ1 is made larger than 90 degrees. Preferably, the angle θ1 is 120 degrees or more. The shape of the recess may be an inverted trapezoid, a U-shape, a conical shape, or a groove with no slope. Further, there may be a portion without a recess in the radial direction. Also, if possible in terms of design, make sure that the total area of the contact surface and other surfaces coplanar with the contact surface (a plane including the surface of the resin-impregnated part) is larger than the area of the back surface (plane on the back side). Make it.

FIG. 1(a) shows a forming process for forming a sintered body having a recessed portion. The sintered body 6a is produced through a step of molding a molded body of raw material powder that is a mixture of SUS410L powder and carbon powder (molding process), and a process of bonding the powders by holding the molded body at a predetermined temperature below the melting point. (sintering process).

The Vickers hardness of the sintered body 6a was measured with a test force of 200 g (=0.2 kg). In order to improve the wear resistance of the frictional sliding surface when the sintered body 6a is used as the contact body 6, the Vickers hardness of the sintered body 6a is set to 550HV0.2 or more. Note that the recessed portion 6b may be formed in the molded body before the sintering process, or may be formed in the sintered body after the sintering process. It is preferable to form the recesses 6b in the molded body before the sintering process, since the cost required for forming the recesses 6b is lower when the recesses 6b are formed in the molded body before the sintering process. In this example as well, the recess 6b was formed in the molded body before the sintering process.

Next, a two-component curing liquid adhesive is prepared in order to impregnate the pores of the sintered body 6a with resin. In this example, the main component of the main agent was a liquid epoxy resin, and the main component of the curing agent was an amine. In addition, GC, which is a hard particle, is dispersed in the resin in order to further enhance the effect of holding power.

FIG. 1(b) and FIG. 1(c) show an impregnation step for forming a resin-impregnated portion in which a sintered body is impregnated with resin. As shown in FIG. 1(b), a liquid epoxy resin 6e is applied to the surface of the sintered body 6a on the side that will become the friction portion using a dispenser device (not shown). After coating, confirm that the resin 6e is coated on at least the entire contact surface 6c. At this time, since the recess 6b is present, it is easier to judge whether or not the surface that the vibrating body 2 may come into contact with, that is, the area that should be coated, is coated, compared to the case where the recess 6b is not present. can.

Thereafter, the surface of the sintered body 6a that is not coated with the epoxy resin 6e is brought into contact with the surface of a hot plate heated to about 80.degree. Thereby, the viscosity of the epoxy resin 6e is reduced by the heat conducted through the sintered body 6a, and the penetration into the pores can be promoted.

Here, the hot plate refers to a device that heats a plate using an electric heater as a heat source. Further, the oven described below is a device that heats in a closed space, and when a steady state is reached, the ambient temperature inside the oven and the temperature of the object to be heated are the same.

FIG. 1(c) shows how the epoxy resin 6e penetrates to a certain distance from the frictional part surface after heating the sintered body 6a. The sintered part impregnated with the epoxy resin 6e is defined as a resin-impregnated part 6f. In the resin-impregnated portion 6f, the proportion of resin decreases as the depth from the surface of the resin-impregnated portion 6f increases. This is because at a depth of about 0 to 50 μm, which is the outermost layer of the sintered body 6a, there are few necking parts where sintered powder joins together, and at a certain depth, outside air cannot pass through and the resin is also filled. This is thought to be due to the appearance of closed pores that do not Another possibility is that the resin flows downward without completely filling the large pores. Thereafter, in order to harden the epoxy resin 6e, it is placed in an oven set at about 80° C. and left for about 30 minutes. Note that the epoxy resin used hardens even at room temperature, so putting it in an oven is not essential. Further, the temperature suitable for heat penetration and the temperature suitable for curing do not need to be the same, but a temperature suitable for the resin used is selected.

In this series of resin impregnation steps, since the amount of resin applied is larger than the amount actually impregnated (penetrated), the cured resin remains on the surface of the sliding part. In order to remove this resin, correct the flatness of the contact part and back surface, and the thickness of the contact body 6 to predetermined values, grinding is performed after the resin curing process, and further to adjust the surface roughness, etc. The contact body 6 is completed by polishing.

Here, in this embodiment, double-sided grinding is used in which both sides are simultaneously ground during grinding. Double-sided grinding uses GC free abrasive grains and a metal surface plate. The reason why double-sided grinding is used instead of single-sided grinding is that single-sided grinding involves a large amount of grinding, making it difficult to maintain good parallelism, and single-sided grinding requires longer machining time.

In double-sided grinding, set on the surface plate with the contact surface facing up to reduce the amount of grinding on the contact surface side as much as possible. Also, the rotation speed of the surface plate is set so that the rotation speed of the upper surface plate is smaller than that of the lower surface plate. Then, both sides are ground until the thickness on both sides reaches a predetermined value. At this time, by increasing the area on the contact surface side with respect to the back surface, the contact pressure on the contact surface side becomes relatively small, so that the amount of grinding on the contact surface side can be made relatively small.

FIG. 1(d) is an enlarged cross-section of the recess 6b of the sintered body 6a and its surroundings. When the width of the opening surface (opening width) of the recess 6 on the same plane as the contact surface is W, and the depth of the recess is h, the width of the recess of the sintered body 6a after sintering (before resin impregnation) (Opening width) W1 and the depth h1 of the recess are known, and the width W2 of the recess after grinding is measured. Since the shape of the recess is determined so that the depth h2 of the recess after grinding is proportional to the width (opening width) W2 of the recess after grinding (constant x W2), the amount of grinding Δh of the recess, i.e. The amount of grinding Δh on the contact surface side is known.

In other words, it can be calculated (derived) using the following formula.
Δh=h1-constant×W2

Here, the "opening surface" refers to a virtual plane including the entire circumference of the edge of the opening (opening edge). Note that Δh can also be derived from W2 without calculation by determining the correspondence between Δh and W2 in advance from the shape in the design drawing or the results of measuring the dimensions of the recessed portion of the actual sintered body 6a. can.

In this way, during double-sided grinding, the variation in the grinding amount ratio between the top and bottom surfaces tends to be large depending on the deterioration status of free abrasive grains, but by controlling not only the thickness but also the width of the recess, it is possible to The amount of grinding can be easily grasped. After grinding, the contact surface 6c is smoothed by polishing (a polishing process in which an opening surface of the recess is formed on a plane including the surface of the resin-impregnated part), as shown in FIG. 1(e). A contact body 6 is obtained. A portion of this contact surface 6c will be slid. The polishing process was performed using a copper surface plate with diamond free abrasive grains (3 μm). A part or all of the pores of the sintered body 6a have a resin-impregnated part impregnated with the epoxy resin 6e, and the contact surface includes the sintered surface, the resin surface in which hard particles are dispersed, and the pores. Configuring.

By understanding the amount of polishing and the relationship between the amount of grinding and the holding torque in advance, and determining the amount of polishing and grinding that is allowed, you can confirm that the width of the recess is at least the specified value. It is possible to verify whether the amount and the amount of grinding are within the allowable values. At this time, if the resin is applied so that it is impregnated into the recessed part, it becomes easy to measure the width of the recessed part. In this embodiment, since the inclination angle of the recess is gentle, the resin easily flows into the recess. Furthermore, since the resin is a recessed portion, the resin that has flowed into a part of the recessed portion flows through the recessed portion along the circumference. Therefore, the entire concave portion is easily impregnated with resin. As a side effect, even if the center of the application circle and the center of the sintered body 6a are misaligned due to the poor roundness of the sintered body 6a, the resin is likely to be impregnated into the entire surface of the contact surface 6c through the recesses. In addition, if a fluorescent dye is added to the resin, it is easier to verify whether the entire contact surface that the protrusions of the vibrator may come into contact with is well impregnated with the resin by observing it with a fluorescence microscope. I can do it.

In this embodiment, the size of the pores in the sintered body 6a varies depending on the location, but has a maximum length of several μm to about 100 μm. In this example, the sintered body was filled with the resin, but the resin may also be filled into a melted stainless steel material with holes formed using a laser or the like. Further, the recesses may also be formed by laser processing, press processing, cutting, etc. after sintering.

<Application example of vibration type actuator>
Possible application examples of the vibration type actuator using the friction material for the vibration type actuator according to the above-described embodiment as a contact body will be described below, taking an imaging device and an industrial robot as examples.

FIG. 6A is a top view showing a schematic configuration of the imaging device 700. The imaging device 700 includes a camera body 730 equipped with an imaging element 710 and a power button 720. The imaging device 700 also includes a lens barrel 740 that includes a lens group and a vibration type actuator (not shown). The lens group is driven by a vibration type actuator. The lens barrel 740 can be replaced as an interchangeable lens, and a lens barrel 740 suitable for the object to be photographed can be attached to the camera body 730. As the vibration type actuator, the vibration type actuator described with reference to FIG. 1 can be used.

Driving a lens by a vibration type actuator is considered to be suitable for driving an autofocus lens, but it is not limited to this, and it is considered that a similar configuration can be used to drive a zoom lens. Further, the vibration type actuator can be used to drive an image sensor, and also to drive a lens or an image sensor during image stabilization.

FIG. 6(b) shows an example in which the vibration type actuator of this embodiment is mounted on a lens barrel of a camera. FIG. 6(b) is a cross-sectional view of the lens barrel. The contact body 11 has a sliding portion that is wear-resistant, and is disposed so as to face and come into contact with the protrusion of the vibrating body 12 . An output transmission member 9 is installed on the surface of the contact body 11 opposite to the sliding portion side, with the rotor rubber (vibration isolating rubber) 8 interposed therebetween.

On the other hand, on the side opposite to the contact body 11 side of the holding base 43 that holds the vibrating body so as not to inhibit vibration, a leaf spring 10 is installed as a pressure means for pressurizing the vibrating body 12 and the contact body 11. It is provided. In addition, in order to compress the leaf spring 10 and generate a pressing force, a pressure ring 18 is provided that regulates the amount of deflection of the leaf spring 10, and the pressure ring 18 and the holding base 43 A spring 10 is held between them. As a result, an appropriate pressing force is applied between the vibrating body 12 and the contact body 11.

The lens barrel unit main body 16 is formed with a flange 16-1 that extends perpendicularly to the direction of the optical axis L, and a manual ring 15 that is turned by hand for manual focusing is attached to one side of this flange. is set up. Further, a roller ring 19 that can be rotated by transmitting the force of the manual ring 15 or the vibration type actuator is installed between the manual ring 15 and the vibration type actuator, and rotates the cam ring etc. via the output key 17 installed on the roller ring 19. It has the function of The roller ring 19 is provided with a plurality of roller shafts 13 extending in the radial direction and rollers 14 that are engaged with the roller shafts and are rotatably attached around the roller shafts. The output transmission member 9 and the manual ring 15 are stacked in the optical axis L direction with the rollers 14 in between. The pressure ring 18 has an inner peripheral side engaged with the lens barrel main body 16 through a screw or bayonet structure. By rotating the pressure ring and moving it in the direction of the optical axis L, the pressure spring 10 is compressed, and the structure is such that the area from the vibrator holding base 43 through the manual ring 15 to the main body flange 16-1 is pressurized and clamped. There is.

When an elliptical motion is formed in the protrusion of the vibrating body 12, a frictional driving force is generated in the contact body 11 that is in contact with the protrusion, so that the contact body 11, the rotor rubber 8, and the output transmission member 9 are Rotates around axis L. The rollers 14 in contact with the output transmission member 9 rotate around the optical axis L together with the roller ring 19 while rolling on the surface of the manual ring 15, and the output key 17 installed on the roller ring 19 causes a cam ring (not shown), etc. Rotate to perform autofocus operations, etc.

A robot 100 equipped with a vibration type actuator will be described using FIG. 7.

Motors used for bending robot arm joints and gripping robot hands are required to have low rotational speed and high torque TN characteristics (drooping characteristics that indicate the relationship between load torque and rotational speed). A vibration type actuator is considered suitable. Therefore, the configuration of an industrial robot as an example of a device (machine) including a vibration type actuator will be described with reference to FIG. 7.

FIG. 7 is a perspective view showing a schematic configuration of a robot 100 equipped with a vibration type actuator, and here, a horizontal articulated robot, which is a type of industrial robot, is illustrated. The vibration type actuator is built into the arm joint part 111 and the hand part 112 in FIG. The arm joint 111 connects the two arms 120 so that the angle at which the two arms 120 intersect can be changed. The hand section 112 includes an arm 120, a grip section 121 attached to one end of the arm 120, and a hand joint section 122 that connects the arm 120 and the grip section 121. The vibration type actuator is used for the arm joint part 111 that changes the angle between the arms 120 and the hand joint part 122 that rotates the grip part 121 by a predetermined angle.

Although the present invention has been described above in detail based on its preferred embodiments, the present invention is not limited to these specific embodiments, and the present invention may take various forms without departing from the gist of the present invention. included.

[Second embodiment]
In the second embodiment, a first modification of the contact body 6 will be described. Note that the sintering process, resin coating process, heat treatment for impregnation and hardening, grinding, and polishing process of the vibrating body 6 and the contact body are the same as in the first embodiment, so detailed explanations will be omitted.

FIG. 4A shows a surface of the sintered body 26a before being impregnated with resin, as seen from the side that contacts the vibrating body, and four recesses 26b and four recesses 26j are provided at 90 degree intervals. Four recesses 26k (not shown) are provided at 90 degree intervals on the surface opposite to the side in contact with the vibrating body, similar to the recesses 26b and 26j.

FIG. 4(b) is a radial cross-sectional view of FIG. 4(a), with the left side being the inner diameter side and the right side being the outer diameter side. The cross-sectional shape of the sintered body is approximately rectangular with chamfered corners. Further, the contact surface 26c that may come into contact with the vibrating body 6 is provided with two recesses, a recess 26b and a recess 26j. A recess 26k is provided on the surface opposite to the surface in contact with the vibrating body 6. Here, the recess 26b has a constant cross-sectional shape with a radial width that does not change in the depth direction. Note that the shape of the recess 26b may be a U-shape, and the width in the radial direction may change midway. The depth of the recess 26b is set to an allowable amount as the amount of polishing or grinding. The recessed portion 26b may be provided not at the molding stage but by post-processing such as a drill after sintering. The recess 26j has an inverted trapezoidal cross-sectional shape. The trapezoidal shape can extend the life of the mold during molding, depending on the size of the sintered body. On the other hand, the recess 26k has a conical shape, has a △ shape in cross section, and becomes smaller as the width in the radial direction becomes deeper. In this embodiment, three types of recesses are provided, and the shape of the recesses is determined by considering the amount of polishing, how detailed the amount of grinding is to be understood, ease of manufacturing, etc. Furthermore, if a recess cannot be provided on the contact surface side due to design space, only the recess 26k on the side opposite to the contact surface may be provided.

The contact surface 26c is on the same plane and is divided into three parts by the recess 26b and the recess 26j. Determine the size. This embodiment is designed so that the protrusion 5 of the vibrating body 2 comes into contact with a part of the central contact surface.

Next, the pores of the sintered body 6a are impregnated with resin. Liquid epoxy resin is applied to the surface of the sintered body 26a that will become the frictional part. After application, ensure that the resin is applied to at least the desired contact surfaces. At this time, since there are the recesses 26b and 26j, the coating is applied to the surface that the vibrating body 2 may come into contact with, that is, the central contact surface 26c, which is the area to be coated, compared to the case where there are no recesses. It is easy to judge whether the

Thereafter, the surface of the sintered body 26a that is not coated with epoxy resin is brought into contact with the surface of a hot plate heated to about 80.degree. Thereby, the viscosity of the epoxy resin is reduced by the heat conducted through the sintered body 26a, and the penetration into the pores can be promoted.

Then, in order to harden the epoxy resin, it is placed in an oven set at about 80°C and left for about 30 minutes. After leaving it, both sides are ground and polished after the resin curing process in order to remove the hardened resin on the contact surface, correct the flatness of the contact part and back surface, and the thickness of the contact body 26 to predetermined values. A contact body shown in FIG. 4(c) is obtained.

Here, since the recesses 26b on the contact surface side are set to an allowable amount as the amount of polishing and grinding, it is possible to determine whether the product is normal or defective depending on whether or not the recesses disappear (whether the number of recesses is 0 or 1). can be easily determined.

If you want to know the detailed amount of polishing or grinding, you can do so by measuring the width of the recess 26j in the same manner as in the first embodiment. Furthermore, by making the depths of the recess 26j and the recess 26b non-identical (the recess 26j and the recess 26b are formed with different depths), a more detailed determination can be made compared to only determining whether the recess 26b has disappeared. The amount of polishing and grinding can be grasped. If the recess has disappeared, the amount of polishing or grinding is found to be greater than or equal to the depth of the recess that has disappeared, and if the recess has not disappeared, the amount of polishing or grinding is the depth of the recess that has not disappeared. This is because it can be seen that it is less than In other words, from the number of measured recesses and the relationship between the number of recesses and the amount of polishing, the amount of polishing can be derived as a value with a range (a value greater than a certain value and less than a certain value). .

By measuring the width of the recess 26k provided on the side opposite to the contact surface in the same manner as in Example 1, the contact surface can be determined from the amount of polishing on the side opposite to the contact surface, the amount of grinding, and the amount of change in the thickness of the sintered body 26a. It is also possible to determine whether the product is normal or defective by understanding the amount of polishing and grinding on the side.

In this embodiment, the recesses are provided intermittently, but the recesses may be provided in an annular shape so that any radial cross section has the cross-sectional shape shown in FIG. 4(c).

[Third embodiment]
In the third embodiment, a second modification of the contact body 6 will be described. FIG. 5A is a plan view of the contact body 36 according to the third embodiment, viewed from the side of the vibrating body 6 that drives the contact body 36. FIG. 5(b) is a cross-sectional view taken along line BB shown in FIG. 5(a), which is a cross-sectional view perpendicular to the driving direction.

The contact body 36 is an embodiment of the contact body 6 described in the first embodiment as a contact body (a linearly formed contact body) of a linear drive vibration type actuator. Note that the configuration and driving principle of a linear drive type vibration actuator using the vibrating body 2 are well known, and therefore, description thereof will be omitted here. Furthermore, the sintering process, resin coating process, heat treatment for impregnation and hardening, grinding, and polishing process of the contact body are the same as those in the first embodiment, and therefore their explanations will be omitted.

The rod-shaped (linear) contact body 36 has a strip-shaped contact surface 36c formed along the length direction of the contact body 36, and recesses 36b and 36j are formed in the same virtual plane as the contact surface 36c. . By measuring the width of the recess similarly to the first embodiment, the amount of polishing and the amount of grinding can be determined, and it is possible to easily determine whether the contact body 36 is a normal product or a defective product.

1 Vibration type actuator 2 Vibrating body 6, 26, 36 Contact body 6a, 26a, 36a Sintered body 6b, 26b, 26j Recessed part 6c, 26c, 36c Contact surface 6e Resin 6f Resin impregnated part

Claims (17)

In a vibration type actuator, a contact body that contacts a vibrating body that generates vibration and moves relative to the vibrating body,
The contact body includes a sintered body and a resin, and has a resin -impregnated part in which the sintered body is impregnated with the resin, and a recessed part formed in a plane including a surface of the resin-impregnated part ,
The contact body is characterized in that the recess has a portion where the opening width narrows at a constant rate as the depth from the opening surface of the recess increases . The contact body is characterized in that the recess has a V-groove shape in which the opening width narrows at a constant rate as the depth from the opening surface increases. The contact body according to claim 1 or 2, wherein the recess is filled with the resin. The recess divides the plane into a contact surface that contacts the vibrating body and a non-contact surface that does not contact the vibrating body,
The angle between the contact surface and the inclined surface of the recess on the contact surface side is such that the angle between the contact surface and the inclined surface adjacent to the contact surface and opposite to the inclined surface of the recess on the contact surface side, The contact body according to any one of claims 1 to 3, wherein the contact body is larger than the angle formed by the contact body. The contact body has an annular or rectangular shape,
When the contact body is annular, the plane including the surface of the resin-impregnated part is a plane that intersects with the central axis of the annular ring of the contact body,
When the contact body is rectangular, the plane including the surface of the resin-impregnated part is a plane whose longitudinal direction is the direction of the relative movement,
According to any one of claims 1 to 4 , the area of the plane is larger than the area of the back surface of the contact body, which is located on the opposite side of the plane including the surface of the resin-impregnated part. Contact body as described. The contact body according to any one of claims 1 to 5, wherein a plurality of recesses each having a different depth are formed as the recess. In a vibration type actuator, a contact body that contacts a vibrating body that generates vibration and moves relative to the vibrating body,
The contact body includes a sintered body and a resin, and has a resin-impregnated part in which the sintered body is impregnated with the resin, and a recessed part formed in a plane including a surface of the resin-impregnated part,
A contact body characterized in that the recesses include a plurality of recesses each having a different depth. In a vibration type actuator, a contact body that contacts a vibrating body that generates vibration and moves relative to the vibrating body,
The contact body includes a sintered body and a resin, and has a resin-impregnated part in which the sintered body is impregnated with the resin, and a recessed part formed in a plane including a surface of the resin-impregnated part,
The recess divides the plane into a contact surface that contacts the vibrating body and a non-contact surface that does not contact the vibrating body,
The angle between the contact surface and the inclined surface of the recess on the contact surface side is such that the angle between the contact surface and the inclined surface adjacent to the contact surface and opposite to the inclined surface of the recess on the contact surface side, A contact body characterized by an angle larger than the angle formed by the contact body. 9. The sintered body is a martensitic stainless steel sintered body, and the resin-impregnated portion contains hard particles. contact body. The contact body according to any one of claims 1 to 9 , wherein the contact body is formed in a rectangular shape. The contact body according to any one of claims 1 to 9 , wherein the contact body is formed in an annular shape. A vibrating body that generates vibration,
A contact body according to any one of claims 1 to 11 ,
A vibration type actuator, characterized in that the vibrating body and the contact body are in contact with each other, and the vibrating body and the contact body move relative to each other. An optical device comprising: an optical element; and the vibration type actuator according to claim 12, which drives the optical element. An imaging device comprising: an imaging device; and the vibration type actuator according to claim 12, which drives the imaging device. An electronic device comprising: a member; and the vibration actuator according to claim 12, which drives the member. In a vibration type actuator, a method for manufacturing a contact body that contacts a vibrating body that generates vibration and moves relative to the vibrating body, the method comprising:
a forming step of forming a sintered body having a recess;
an impregnation step of forming a resin-impregnated portion in which the sintered body is impregnated with resin;
A method for manufacturing a contact body, comprising: polishing the sintered body to form an opening surface of the recess on a plane including the surface of the resin-impregnated part. 17. The method of manufacturing a contact body according to claim 16 , wherein in the forming step, a plurality of recesses each having a different depth are formed as the recesses.

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