JP2001008474A - Vibration driving device, manufacture thereof and apparatus provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve abrasion form made on the sliding face of a vibration body hardening film by providing a tapered sliding face formed by cutting for a vibration body on a contact body. SOLUTION: A mobile body (contact body) 7 is constituted of a support body 5 made in a circular form and a composite resin layer 6, which is concentrically fixed to the surface. The surface of the composite resin layer 6 has a taper-like sliding face. In the other surface, an escape part of the sliding face is formed on the outside diameter side of the taper-like sliding face. The taper form of the sliding face of the resin layer 6 in the mobile body is cut by an NC lathe, and the surface form shows a step form. When the mobile body 7 of the tapered sliding face is incorporated in a vibration wave motor and pressure force is added to the mobile body in an axial direction with a compression spring member 14, the sliding face of the movable body 7 is brought into contact with the sliding face of the plane of a vibration body 2 by the part of an outer diameter side, and an extremely small gap is formed in an inner diameter part. Thus, the fitting of the tapered sliding face with respect to the planar sliding face of a hardened film is fast and abrasion can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-type driving device, a method of manufacturing the vibration-type driving device, and a device having the vibration-type driving device. It relates to the sliding surface of the body.

[0002]

2. Description of the Related Art A vibration-type driving device called a vibration wave motor or the like uses a friction between a vibrating body and a contact body pressed against the vibrating body to transfer kinetic energy of high-frequency vibration of the vibrating body to a contact body ( This is a type of power generation source that converts it into continuous mechanical kinetic energy. For this reason,
The state of contact between the two sliding contact surfaces is particularly important, and both sliding contact surfaces must be formed of a material having high wear resistance.

The ring-shaped vibrating body and the ring-shaped moving body of the conventional vibration type driving device both have a flat sliding contact surface and have flexibility in the axial direction. Have. Then, both are supported concentrically, and in a state where the sliding contact surfaces are in contact with each other,
Assembling is performed by applying a predetermined pressing force in the axial direction (driving pressing force). At this time, in a state where the driving pressure is applied, the sliding contact surface of the moving body comes into contact with the sliding contact surface of the vibrating body on the inner diameter side, and there is a gap on the outer diameter side and there is no contact. State. Further, the moving body is fixed to a rotating shaft as an output shaft supported by a ball bearing at a center of rotation, and the rotating shaft rotates integrally with the moving body.

The sliding contact surface of the vibrating body is formed, for example, by electroless nickel plating (Ni) of a ternary alloy having a thickness of about 20 μm.
-P-B) is formed, which is heated and cured at 200 ° C. to form a sliding surface having a Vickers hardness (Hv) of about 800.

The sliding contact surface is finished by grinding or polishing the cured film to a flatness of 3 μm or less.

On the other hand, the sliding surface of the moving body is made of, for example, polyethernitrile (PEN) which is a thermoplastic resin, and PAN-based carbon fiber as a reinforcing material in a weight ratio of 10%.
A composite resin layer filled with about 30% and, if necessary, a fluoroplastic (PTFE) as a solid lubricant and graphite powder is added.

[0007] To finish the sliding contact surface of this moving body, the composite resin layer is cut with a cutting tool to obtain dimensions, and then ground or polished to a flatness of 3 µm or less. .

As described above, the sliding contact surface of the vibrating body is a flat hardened film having high hardness and high toughness, and the sliding contact surface of one moving body is formed of a flat surface excellent in heat resistance and wear resistance. The reason why the composite resin layer is used is that it is considered that the friction coefficient between the sliding contact surfaces of the two is steadily stabilized and it is possible to minimize the wear of both.

[0009]

However, in the conventional vibration type driving device as described above, the rotational load is reduced to 5 kggc.
m, and a continuous operation test was performed for 2,700 hours at a rotation speed of 64 rpm.As a result, the wear of the composite resin layer forming the sliding surface of the moving body was slightly beyond the target range, and the sliding surface of the vibrating body was The wear of the formed cured film was observed as wear marks in the circumferential direction, and the cross section of the wear marks in the radial direction showed an inclined wear form in which the inner diameter side was deep and the outer diameter side was shallow. Therefore, it was found that the amount of wear and the form of wear needed to be improved.

At this time, a large amount of the abrasion powder is discharged on the inner diameter side than on the outer diameter side, and the abrasion powder is transferred between the ball bearing and the rotating shaft. It was found that there was an adverse effect on the surface, and that the abrasion of the sliding contact surface was not good.

In addition, when the driving performance (torque and the like) of the vibration type driving device is measured during the continuous operation, the driving performance fluctuates with time and decreases. In other words, the driving performance was largest at the beginning of operation, decreased with time, decreased to about 500 hours, and then decreased gradually to about 2,700 hours.

The cause is that in the initial stage of operation, the respective sliding contact surfaces of the vibrating body and the moving body are in contact only in the vicinity of the inner diameter portion, and the pressing force per unit area of the contact portion is larger than the set value. Therefore, after 1,800 hours, the sliding surfaces are almost flat, and in 2,700 hours, they come into contact with the specified sliding surface area, and the pressing force per unit area is also the set value. As a result, the driving performance is almost settled.

It is an object of the invention according to the present application to reduce the temporal fluctuation of the driving performance in continuous operation of a vibration type driving device, minimize the wear of the sliding surfaces of the vibrating body and the contacting body as much as possible, An object of the present invention is to provide a vibrating body driving device in which a form of wear formed on a sliding contact surface of a body cured film is improved.

Further, the conventional motor has a problem that the machining cost is high because the sliding contact surface is formed by performing grinding or polishing after cutting.

According to the present invention, the sliding surface of at least one of the vibrating body and the contact body is finished only by the cutting of the NC lathe to reduce the number of processing steps and to reduce the cost.

[0016]

According to a first aspect of the present invention, there is provided a vibration-type driving apparatus comprising: a vibrating body in which vibration is excited; and a contact body which presses and contacts the vibrating body. A vibration-type driving device for relatively moving the vibrating body and the contact body, wherein the driving means for pressing the vibrating body and the contact body against one of the vibrating body and the contact body. It has a pressurizing part for applying a pressing force and a tapered sliding contact surface formed by cutting.

A second configuration of the vibration type driving device for realizing the object of the present invention according to the present application is the above configuration, wherein the taper angle of the tapered sliding contact surface is set to each of the vibration member and the contact member. Are set so as to contact at least from the outer diameter side.

According to a third aspect of the present invention, there is provided a vibration type driving apparatus according to any one of the above aspects, wherein the tapered sliding contact surface has a stepped surface texture. It is.

A fourth configuration of the vibration type driving device for realizing the object of the invention according to the present application is any one of the above configurations, wherein one of the vibrating body and the contact body is the contact body. The sliding contact surface of the contact body is formed of a composite resin layer containing at least a reinforcing material in a resin or a resin composition.

A fifth configuration of the vibration type driving device for realizing the object of the invention according to the present application includes a vibrating body whose vibration is excited,
A vibratory drive device having a contact body that presses and contacts the vibrating body, wherein the sliding contact surface of the contact body is cut by an NC lathe to form a tapered surface. And the sliding surface of the vibrating body is formed into a flat surface by cutting with an NC lathe.

According to a sixth aspect of the vibration type driving device for realizing the object of the invention according to the present application, the sliding contact surface of the contact body is formed of a cured film of electroless plating. Is what it is.

According to a seventh aspect of the vibration type driving device for realizing the object of the invention according to the present invention, the sliding contact surface of the vibrating body has at least a reinforcing material in a resin or a resin composition. It is formed of a composite resin layer containing.

A first configuration of a method of manufacturing a vibration type driving device for realizing the object of the invention according to the present application has a vibrating body in which vibration is excited, and a contact body that comes into pressure contact with the vibrating body. ,
In a vibration type driving device for relatively moving the vibrating body and the contact body, a tapered sliding contact surface formed on one of the vibrating body and the contact body is cut by a lathe using a diamond tool.

A second configuration of the method of manufacturing the vibration type driving device for realizing the object of the invention according to the present application is that the nose (edge) R of the diamond cutting tool is in the range of 0.1 to 2 mm.

An apparatus provided with a vibration type driving device for realizing the object of the invention according to the present application includes the vibration type driving device having the above-described first to seventh configurations as a driving source.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows an overall configuration of a vibration wave motor (vibration type driving device) according to a first embodiment of the present invention, and FIG. Further, a vibrating body and a moving body (contact body) constituting the vibration wave motor are shown in an enlarged manner.

In these figures, reference numeral 1 denotes a thin ring-shaped piezoelectric element. Reference numeral 2 denotes a vibrating body made of an elastic material and having flexibility in the axial direction. On the sliding contact surface of the vibrating body 2, four protrusions (comb teeth) per λ / 2 are formed at equal intervals on the entire circumference. It is formed over. And the surface of each comb tooth (
On the sliding contact surface), a cured film of the same type as the conventional vibration wave motor, that is, a ternary alloy electroless nickel plating (Ni-P-B) is formed, which is heated and cured at 200 ° C. A sliding surface with a Vickers hardness (Hv) of about 800 is used, and the sliding surface of this cured film is polished to a flatness of 3 μm or less and a surface roughness (Ra) of about 0.02 μm. Finished.

The entire surface of the electrode surface of the piezoelectric element 1 is fixed to the surface of the vibrating body 2 opposite to the sliding contact surface, and a flexible electrode (not shown) is provided on the surface of the piezoelectric element 1. The printed board is fixed, and the three components constitute a stator.

Reference numeral 3 denotes a motor substrate of the vibration wave motor, and the vibrating body 2 is fixed concentrically by screws 4. The outer race of the first ball bearing 11 is fixed to the center of the motor board 3.

Reference numeral 10 denotes a rotating shaft, and an intermediate member 15 is fixed to the axially intermediate portion of the rotating shaft 10 by, for example, shrink fitting. One end of the rotating shaft 10 is supported by the inner race of the first ball bearing 11 so as to be slidable in the axial direction.
The inner ring of the second ball bearing 12 is slidably supported in the axial direction. The outer ring of the second ball bearing 12 is
Is fixed to the center of the substrate cover 8 fixed with screws 9.

A ring-shaped moving body 7 is provided concentrically on the outer peripheral portion of the intermediate member 15.

The moving body 7 comprises a support 5 made of an aluminum alloy in a ring shape and a composite resin layer 6 concentrically fixed to the surface of the support 5 with an adhesive. The composite resin layer 6 is composed of a thermoplastic resin, polyether nitrile (Idemitsu PEN) having a glass transition point of 100 ° C. or higher, a PAN-based carbon fiber as a reinforcing material in a weight ratio of 20%, and a lubricant as a fluorine agent. Resin (PTFE) and graphite powder are filled at 10% and 5% by weight, respectively.

As shown in FIG. 2, the support 5 includes a fixed portion 5b connected to the flange portion of the intermediate member 15, a sliding portion 5a to which the composite resin layer 6 is fixed, and a sliding portion 5a. And a connecting portion 5c having a thin portion connecting the fixing portion 5b and the fixing portion 5b.

An elastic sheet member 17 made of rubber is interposed between the fixed portion 5b of the support 5 and the flange portion of the intermediate member 15, and the intermediate member 15 and the second ball bearing are interposed.
The axial pressing force generated by the compression spring member 14 provided between the inner ring 12 and the inner ring 12 acts on the support 5 in the axial direction via the elastic sheet member 17. Due to this axial pressure, the sliding surface of the moving body 7 (the surface of the composite resin layer 6) is pressed against the sliding surface of the vibrating body 2.

The axial pressure (driving pressure) generated by the compression spring member 14 is provided by a spacer member (not shown) provided between the inner ring of the second ball bearing 12 and the compression spring member 14. Can be adjusted.

Next, the processing of the sliding contact surface (the surface of the composite resin layer 6) of the moving body 7 in the vibration wave motor thus configured will be described with reference to an enlarged view of the moving body 7 in FIG.

The surface of the composite resin layer 6 fixed to the support 5 has at least one tapered sliding contact surface, and the other surface is outside the tapered sliding contact surface as shown in the figure. A relief portion of the sliding contact surface is formed on the radial side.

In the present embodiment, the taper angle (θ) of the tapered sliding contact surface of the composite resin layer 6 is set.
Is set to 0.2 degrees (12 minutes) so that the respective sliding surfaces of the vibrating body 2 and the moving body 7 come into contact at least from the outer diameter side, and the height (h) of the tapered portion is 2.4 μm It is about.

The tapered shape of the sliding surface of the resin layer 6 of the moving body 7 is cut by an NC lathe using a diamond tool, and the surface property generally shows a step shape. The processing conditions for the NC lathe are the surface roughness of the sliding contact surface (R
In consideration of a), for example, the rotation speed is set to 1,000 rpm, and the feed amount per rotation in the radial direction is set to 14 μm. The nose (edge) R of the diamond cutting tool is selected from the range of 0.1 to 2 mm. In order to reduce the surface roughness (Ra) of the sliding contact surface, 1 mm is used, and the surface roughness (Ra) is reduced. ) Is 1 μ
A sliding contact surface of about m is obtained.

In the composite resin layer, polyethernitrile (Idemitsu PEN) as a base resin is filled with high-hardness carbon fiber as a reinforcing material. I can't get it. Even if a diamond tool is used, if the nose (edge) has a diameter R of 0.1 mm, the cutting is poor and the surface roughness is slightly reduced. Similarly, processing conditions such as the number of revolutions of the NC lathe or the feed amount per rotation are set in relation to the required surface roughness.

When the movable body 7 having the tapered sliding contact surface obtained by the cutting process is assembled into a vibration wave motor, and the compression spring member 14 applies an axial pressing force to the movable body 7,
The sliding contact surface of the moving body 7 is in contact with the flat sliding contact surface of the vibrating body 2 at the outer diameter side portion, and a very small gap is formed at the inner diameter portion.

Here, Table 1 shows target performance of the vibration wave motor of the present embodiment, and Table 2 shows design specifications.

[0043]

[Table 1]

[0044]

[Table 2]

As a moving body of the vibration wave motor having the structure shown in FIG. 1 according to the above design specifications, a vibration wave motor incorporating the moving body 7 of the present embodiment was manufactured. I did a driving test.

In the test, a perma torque (trade name: manufactured by Kosin Seisakusho) was connected to the output side of the rotating shaft 10 of the motor.
The rotating load was set to 5 kggcm, the rotating plate of the encoder was supported at the other end of the rotating shaft 10, and the rotation was controlled at a constant 64 rpm.
A 2,700-hour continuous operation test was performed.

The performance of the motor was measured at 900-hour intervals, and the time variation of the motor performance was confirmed. Fluctuations in performance were measured by measuring the torque generated when the vibrating body was driven with the rotation speed fixed at 64 rpm and the vibration amplitude of the vibrating body kept constant. The setting of the vibration amplitude was performed by setting the output voltage values from the two detection electrodes of the piezoelectric element 1 fixed to the vibrating body 2 to the same constant voltage value. The wear of the sliding surfaces of the vibrating body and the moving body is 2,
After the continuous operation test for 700 hours, the measurement was performed to confirm the effect.

With the conventional motor, when starting operation, 10 kg
Although a torque of 1 cm was generated, the torque value dropped to a little less than 8 Kgcm after 500 hours, decreased to about 7 Kgcm after 1,800 hours, and decreased to less than 7 Kgcm after 2,700 hours.

On the other hand, in the motor of this embodiment,
8 Kgcm at the start of operation, 9 Kgcm after 900 hours, 1,80
At 0 hours, 9 Kgcm, at the end of 2,700 hours of operation, the torque value was slightly less than 9 Kgcm, which was much smaller than that of the conventional motor.

The reason why the torque value is slightly small at the start is that the tapered angle of the tapered sliding surface of the moving body is slightly too large, so that the minute gap on the inner diameter side of the sliding surface becomes large. This is because it took a lot of time to be familiar.

At a rotational speed of 64 rpm and a rotational load of 5 kgcm, 2,
Composite resin layer 6 of moving body 7 when operated continuously for 700 hours
The wear amount of the conventional motor was 35 μm, and the wear rate per hour was 0.013 μm. However, the motor of the present embodiment was 24 μm, and the wear rate was improved to 0.009 μm.

On the other hand, when the amount of abrasion of the cured film of the vibrating body 2 after 2,700 hours was measured, the conventional motor showed a circumferential wear mark having a width of 0.7 mm, an inner diameter side depth of 3 μm, and an outer diameter of 3 μm. The motor of this embodiment has a width of 0.7 mm and an inner diameter of 1.3 μm, while the radial side has a slanted wear shape with a depth of about 2 μm.
m, a substantially parallel wear pattern with an outer diameter side depth of 1.5 μm, which was also improved.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
The vibration body and the moving body of the vibration wave motor according to the embodiment are shown in an enlarged manner. Note that the combination of the vibrating body and the moving body according to the present embodiment is compatible with the combination of the vibrating body 2 and the moving body 7 of the vibration wave motor according to the first embodiment. The vibration wave motor according to the second embodiment can be configured by incorporating the vibration wave motor of the second embodiment.

In FIG. 4, reference numeral 1 denotes a piezoelectric element, and 52 denotes a vibrating body to which the piezoelectric element 1 is fixed. This vibrator 52 is
The same material and the same shape as the vibrating body 2 of the first embodiment are used.

Reference numeral 56 denotes a composite resin layer fixed to the comb tooth surfaces of the vibrating body 52. The composite resin layer 56 is formed of a composite resin obtained by filling a base resin or a resin composition with a reinforcing material or a mixture of a reinforcing material and a lubricant.

Reference numeral 57 denotes a moving body, which is made of the same aluminum alloy as the moving body 7 (support 5) of the first embodiment, and has almost the same shape and dimensions. The sliding contact surface is the moving body 7 of the first embodiment.
After being cut at a taper angle θ in the same manner as described above, a cured film of electroless plating similar to that applied by the vibrating body 2 in the first embodiment is formed.

In the moving body 57 of the second embodiment, the first
The shape and dimensions may be the same as those of the moving body 7 of the embodiment, and after the electroless plating is performed, the tapered shape processing may be performed using a diamond tool of an NC lathe, and finally, the cured film may be subjected to a heat treatment.

The sliding surface of the composite resin layer 56 fixed to the vibrating body 52 is finished to a flat sliding surface by cutting with an NC lathe.

When the motor of the present embodiment is operated continuously, the fluctuation of the torque value becomes small, as in the first embodiment, and the composite resin layer 56 of the vibrating body 52 or the moving body 57
It can be expected that the amount of wear on each sliding contact surface of the cured film becomes smaller than that of a conventional motor.

In each of the above embodiments, a case has been described where the tapered sliding contact surface is formed on the moving body (contact body). However, in the present invention, the tapered sliding contact surface is formed on the vibrating body. The present invention may be applied to a vibration type driving device in which a flat sliding contact surface is formed on a moving body. Various devices are proposed as devices for driving a driven body using the vibration wave driving device of each of the above-described embodiments as a driving source, but the feature is that highly accurate positioning of the vibration wave driving device is possible. It is used for a paper feed mechanism of a printer, a carriage of an ink head of an ink jet printer or the like, or a drive source of a photosensitive drum of a copying machine.

[0061]

As described above, according to the present invention, since a tapered sliding contact surface is formed on a moving body (or vibrating body) with high precision using an NC lathe, the vibrating body (or moving body) is hardened. The tapered sliding surface of the moving body (or the vibrating body) is quickly adapted to the planar sliding contact surface of the film, and a predetermined axial pressing force per unit contact area is quickly obtained. For this reason, it is possible to reduce the wear of each sliding contact surface, and it is possible to realize a vibration type driving device having a stable performance with a small fluctuation in driving performance over time.

Further, in forming a sliding contact surface of a moving body (or a vibrating body), a cutting process of an NC lathe employing a diamond bite is performed. By setting the processing conditions, dimensional accuracy and flatness are good, and a small surface roughness is obtained. Can be formed. Therefore, unlike the conventional processing method, post-processing such as grinding or polishing after cutting is not required, so that the processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vibration wave motor according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of a vibrating body and a moving body of FIG. 1;

FIG. 3 is an explanatory view of processing of a sliding contact surface of the moving body in FIG. 1;

FIG. 4 is a partially enlarged sectional view of a vibration wave motor according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2, 52 Vibration body 5 Support body 6, 56 Composite resin layer 7, 57 Moving body

Continued on the front page F term (reference) 5H680 AA00 AA12 BB01 BB16 BC04 DD01 DD02 DD15 DD23 DD35 DD53 DD55 DD66 DD73 DD87 DD92 DD93 EE03 EE11 EE23 FF01 FF04 FF08 FF12 FF14 FF17 GG11 GG25 GG41 GG42 GG43 GG44

Claims (10)

[Claims] 1. A vibration-type driving device comprising: a vibrating body for exciting vibration; and a contacting body that presses and contacts the vibrating body, and relatively moves the vibrating body and the contacting body. A pressurizing portion for applying a driving pressure for pressing the vibrating body and the contact body against one another, and a tapered sliding contact surface formed by cutting. A vibration type driving device characterized by the following. 2. The taper angle of the tapered sliding contact surface is set such that the respective sliding contact surfaces of the vibrating body and the contact body contact at least from the outer diameter side. Item 4. The vibration type driving device according to Item 1. 3. The tapered sliding contact surface has a stepped surface texture.
The vibration-type driving device according to item 1. 4. One of the vibrating body and the contact body is the contact body, and a sliding contact surface of the contact body is formed of a composite resin layer containing at least a reinforcing material in a resin or a resin composition. The vibration type driving device according to claim 1, wherein: 5. A vibration-type driving device comprising: a vibrating body for exciting vibration; and a contact body that presses and contacts the vibrating body, wherein the vibrating body and the contact body are relatively moved. Wherein the sliding contact surface of the vibrating body is formed by cutting with an NC lathe to form a tapered surface, and the sliding contact surface of the vibrating body is formed by cutting with an NC lathe. 6. The vibration type driving device according to claim 5, wherein the sliding contact surface of the contact body is formed by a cured film of electroless plating. 7. The vibration type driving device according to claim 5, wherein the sliding contact surface of the vibrator is formed of a composite resin layer containing at least a reinforcing material in a resin or a resin composition. 8. A vibrating body in a vibration-type drive device, comprising: a vibrating body in which vibration is excited; and a contacting body that presses and contacts the vibrating body, wherein the vibrating body and the contacting body move relative to each other. A method of manufacturing a vibration type driving device, characterized in that a tapered sliding contact surface formed on one of the contact bodies is cut by a lathe using a diamond tool. 9. The method according to claim 8, wherein a nose (edge) R of the diamond cutting tool is in a range of 0.1 to 2 mm. 10. A device comprising the vibration type driving device according to claim 1 as a driving source.