JP4217459B2 - Vibrator, vibrator manufacturing method, vibration wave drive device, and device having the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a vibrator that includes an electro-mechanical energy conversion element and an elastic member, and generates a vibration in the elastic member by supplying a signal to the electro-mechanical energy conversion element, a method for manufacturing the vibrator, and a vibration using the vibrator The present invention relates to a wave drive device and a device on which the wave drive device is mounted.
[0002]
[Prior art]
There have been many proposals related to vibration type driving devices such as ultrasonic motors.
[0003]
For example, a piezoelectric element which is a kind of electro-mechanical energy conversion element and a flexible printed board for supplying an AC voltage to the piezoelectric element are arranged between two elastic members such as metals, and the center of each of these members A bolt is inserted into the through hole provided in the bolt, and a nut is fastened to the tip of the bolt, so that the two elastic members, the piezoelectric element, and the flexible printed board are sandwiched and fixed by a flange and a nut formed on the bolt. There is one that constitutes a vibrator. In addition, there is a screw configured in an inner diameter portion of the elastic member, and by tightening the screw and the bolt, there is a vibrator configured by sandwiching and fixing these two elastic members, a piezoelectric element, and a flexible printed circuit board ( For example, see Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-8472 A (page 3-5, FIGS. 1 and 3)
[0005]
[Problems to be solved by the invention]
In the past, so-called Langevin type vibrators in which a piezoelectric element is sandwiched between elastic bodies and tightened with bolts have been used for a wide range of applications, not limited to vibration wave driving devices.
[0006]
One reason for this is that by fastening the central portion of the vibrator, the members sandwiched between the elastic members are uniformly adhered, and the vibration characteristics of the vibrator are stabilized. In order to efficiently transmit the minute displacement generated in the piezoelectric element to the elastic member, it is necessary to increase the adhesion of each member.
[0007]
Therefore, a large tension is required for the fastening portion of the elastic member, and a high-strength bolt is used as a fastening member that can withstand this tension.
[0008]
However, if the vibrator is downsized, the bolt must be downsized. Since the torsional breaking torque of the bolt is proportional to the cube of its diameter, when the vibrator is downsized, the torsional strength of the bolt is abruptly reduced and the bolt may be broken when the elastic member is tightened.
[0009]
In addition, if a minute slip occurs between the screw threads at the fastening portion of the bolt, the efficiency of transmitting the vibration displacement of the piezoelectric element to the elastic member can be reduced. Furthermore, since the screw thread has a spiral shape, it is not completely symmetrical with respect to the axis of the bolt, and the vibration displacement of the vibrator is also expected to lack symmetry.
[0010]
If the vibration displacement is not symmetric, in the vibration wave drive device using this vibrator, non-uniform pressurization will occur on the friction surface of the vibrator and the slider, resulting in uneven wear of the friction surface and a decrease in drive efficiency. Can be considered.
[0011]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention provides a vibrator in which an electro-mechanical energy conversion element is fixed between a plurality of elastic members.An adhesion force is applied to the plurality of elastic members and the electromechanical energy conversion element.Electrical resistance welding of the plurality of elastic membersAnd heat shrinkIt is characterized by being joined.
[0012]
  Similarly, in order to solve the above-described problem, the present invention provides a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members.,in frontA fastening member which is a separate member from the plurality of elastic membersThe plurality of elastic members and the fastening member so as to apply an adhesion force to the plurality of elastic members and the electro-mechanical energy conversion elementAnd the electric resistance weldingThe plurality of elastic members through the fastening member.It is characterized by being joined.
[0013]
  Similarly, in order to solve the above problems, the present invention provides a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members, and has a fastening member that is a separate member from the plurality of elastic members. AndThe adhesive force is applied to the plurality of elastic members and the electromechanical energy conversion element.Electrical resistance welding of a fastening member and at least one elastic memberHeat shrink, and through the fastening memberThe plurality of elastic members are joined.
[0014]
Similarly, in order to solve the above-described problems, the present invention provides a vibration wave driving device using the vibrator and a device having the vibration wave driving device.
[0015]
  Similarly, in order to solve the above problem, the present invention provides an electro-mechanical energy conversion element between a plurality of elastic members.FixedIn the manufacturing method of the vibrator,AboveMultiple elastic membersAnd adhesion force to the electro-mechanical energy conversion elementElectrical resistance welding of the plurality of elastic membersAnd heat shrinkIt is characterized by being joined.
[0016]
  Similarly, in order to solve the above problem, the present invention provides an electro-mechanical energy conversion element between a plurality of elastic members.FixedIn the vibrator manufacturing method,Multiple elastic members joinFastening partAboveAfter pressurizing in the axial direction of the vibrator,An adhesion force is applied to the plurality of elastic members and the electromechanical energy conversion element.Electric resistance welding of the fastening partAnd heat shrinkIt is characterized by joining.
  Similarly, in order to solve the above-described problem, the present invention provides a vibrator manufacturing method in which an electromechanical energy conversion element is fixed between a plurality of elastic members, and is a fastening member that is a separate member from the plurality of elastic members. The first elastic member so as to apply an adhesion force to the plurality of elastic members and the electro-mechanical energy conversion element after pressing the fastening member in a direction in which the elastic member is present. The fastening member is subjected to electric resistance welding to be thermally contracted and joined.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1 to 3 show a vibrator of the vibration wave driving device according to the first embodiment.
[0018]
In the first embodiment, projections (or projections) 1a and 2a are provided on the mutually opposing surfaces of the two elastic members 1 and 2, respectively, and a current is passed through the elastic member to locally melt the tip of the projection. Two elastic members were welded and joined by electric resistance welding (spot welding).
[0019]
FIG. 1 is a view showing a cross section of a vibrator and welding electrodes 31 and 32 before electric resistance welding.
[0020]
The two elastic members 1 and 2 are made by cutting free-cutting austenitic stainless steel JIS standard SUS303, and have a through hole in the center of which an output shaft is arranged.
[0021]
The material of the elastic member is not limited to austenitic stainless steel, but may be martensitic stainless steel, ferritic stainless steel, copper alloy such as brass, and aluminum alloy. However, in consideration of the deformation strength of the fastening portion, generally, an iron-based material is preferable because the deformation resistance is larger than that of a non-ferrous metal.
[0022]
Among the iron-based materials, austenitic stainless steel is preferable for electric resistance welding as will be described later. This is because the electrical resistance is relatively large and the heat conduction is small, so that the melted portion (nugget) is localized and only the necessary portion is reliably joined.
[0023]
On the other hand, even if it is free-cutting steel, carbon steel or alloy steel instead of stainless steel, a rust-proofing effect that can withstand practical use can be obtained by applying surface treatment such as chromate treatment, nickel plating or chrome plating. When using these, it is good to remove the surface treatment of a welding part, or to select the welding conditions which can be joined with surface treatment.
[0024]
In this embodiment, the elastic member is manufactured by cutting. However, if the elastic member is manufactured by pressing, austenitic stainless steel represented by JIS standard SUS304 is suitable. This is because the ductility is large and drawing is easy, and since the free-cutting component is not included, the welded state is good.
[0025]
The friction materials 6 and 7 are obtained by press-punching a martensitic stainless steel plate, quenching and hardening, and then further improving the surface hardness by gas nitriding using ammonia decomposition gas.
[0026]
When nitriding or carburizing is applied to stainless steel, the surface becomes extremely hard and the wear resistance is remarkably improved, making it ideal as a friction material for vibration wave drive devices.
[0027]
Even if nitriding treatment is applied to normal soft iron, the surface hardness is about 500 Hv (Vickers hardness), but since chromium is contained in stainless steel, chromium nitride is formed and hardness of 1000 Hv or more is easily formed. can get.
[0028]
The friction materials 6 and 7 were lapped on the end surfaces after improving the surface hardness. The lapping machine is made of copper, and diamond abrasive grains are sprayed on it.
[0029]
The friction material subjected to the above treatment was previously joined to the elastic member by electric resistance welding. However, when the friction material is thin, the friction material may be deformed after being welded to the elastic member. Therefore, it is desirable to lap the friction surface of the friction material after welding.
[0030]
In this embodiment, as described above, the elastic members 1 and 2 and the friction materials 6 and 7 are made of stainless steel. Since the two elastic members 1 and 2 are the same type of material, their melting points are close to each other and they are easy to melt together, so that they are suitable for welding.
[0031]
Further, between the two elastic members 1 and 2 joined with the friction materials 6 and 7, an annular piezoelectric element 3, a flexible printed board (feeding board) 4 for feeding an alternating signal to the piezoelectric element, and a vibration wave A support plate 5 for supporting the entire drive device is arranged as shown in FIG.
[0032]
FIG. 2 is an enlarged view of portions of the elastic members 1 and 2 that are welded to each other. FIG. 2A is an enlarged view before welding, and FIG. 2B is an enlarged view after welding.
[0033]
Since the piezoelectric element has high insulation characteristics, and the substrate portion of the flexible printed board uses a highly insulating material such as a polyimide film, the welding current applied to the elastic members 1 and 2 is not applied to these members. Almost does not flow and flows concentrated on the fastening portions 1a and 2a of the elastic members 1 and 2.
[0034]
Further, the projection 1a, which is a fastening portion of the elastic member 1, is provided with a convex portion 1aa called a projection, and a portion of the convex portion 1aa is crushed by pressure contact with the other fastening portion, so that a current flows. A certain area is secured. At the time of welding, the current density of the convex portion 1aa increases and heat generation increases, and this portion can be effectively melted.
[0035]
By the way, when the piezoelectric element is heated, depolarization proceeds, and once the Curie temperature is exceeded, the piezoelectric characteristics are lost even if the temperature is returned to room temperature. Therefore, care must be taken so that heat is not applied to the piezoelectric element as much as possible at the time of welding, but in the first embodiment, the generated heat is local, and thus the characteristics of the piezoelectric element are not deteriorated.
[0036]
Also in this respect, it can be said that the electric resistance welding method in which the material is completely melted and solidified in an extremely short time is suitable for joining the vibrator using the piezoelectric element.
[0037]
In the present embodiment, the fastening portions 1a and 2a are provided on the inner peripheral portion of the elastic member, and are configured to cover the periphery of the hole portion through which the output shaft passes. The fastening portions 1a and 2a are formed in a conical shape in which the surface facing the piezoelectric element is inclined with respect to the output shaft.
[0038]
Therefore, the center position of the piezoelectric element 3, the support plate 5, and the flexible printed circuit board 4 is easily determined by contacting the outer peripheral surfaces of the fastening portions 1a and 2a. Further, the inner diameter portion of the piezoelectric element 3 is in contact with only the root portion where the diameters of the fastening portions 1a and 2a are maximum.
[0039]
That is, a gap S2 exists between the inner diameter portion of the piezoelectric element 3 and the welded portion of the fastening portions 1a and 2a, and the piezoelectric element 3 is hardly heated. Of course, the shape of the fastening portions 1a and 2a is not limited to that shown in FIG.
[0040]
The upper electrode 31 and the lower electrode 32 in FIG. 1 are chromium copper electrodes, and are connected to a welding machine.
[0041]
The elastic members 1 and 2 are sandwiched between the electrodes, and the contact surface is pressurized so that the electric resistance is reduced at the contact surface between the electrode and the work, and a current is passed. Then, the protrusions 1a and 2a of the elastic members 1 and 2 are melted, and as shown in FIG. 2B, the gap S1 that existed immediately before welding disappears, and the elastic member, the piezoelectric element, the flexible printed circuit board, and the support plate are in close contact with each other. Welding is completed.
[0042]
In FIG. 1, when the side surfaces of the upper and lower electrodes 31 and 32 come into contact with the inner diameter portion of the elastic member and current flows therethrough, the electrodes 31 and 32 are welded to the elastic members 1 and 2, or dust ( Insulating paint is preferably applied to the side surfaces of the electrodes 31 and 32 in advance. Of course, a highly insulating member such as a polyimide film may be placed on the electrode.
[0043]
The effect of joining a plurality of elastic members constituting the vibrator by electric resistance welding will be described below.
[0044]
As described above, in order to improve the adhesion of the piezoelectric element or the like, a high fastening tension is required as in the case of bolt joining.
[0045]
In this embodiment, the diameter of the vibrator is 12 mm, and thus the diameter of the elastic member and the piezoelectric element constituting the vibrator is also 12 mm. However, the piezoelectric element and the like sandwiched between the elastic members is about 300 kgf as a whole. It was found by another measurement that good vibrator characteristics cannot be obtained unless a sufficient clamping force is applied.
[0046]
When the clamping force is smaller than that, the Q value indicating the difficulty of damping the vibration and the admittance of the vibrator are small, and the characteristics of the vibrator are not excellent.
[0047]
In the vibrator of the present embodiment, the force with which each electrode pushes the elastic member during welding is set to only about 30 kgf. Nevertheless, the vibrator characteristics after welding were extremely excellent. That is, a force larger than the pressure applied by each electrode is generated in the fastening portion.
[0048]
This is considered that most of the fastening tension generated in the elastic member is caused by thermal contraction of the fastening portions 1a and 2a. That is, it is considered that a strong bonding tension was generated in the process of solidifying again after the contact, and further cooling after the distance between the elastic members was rapidly reduced by melting the entire surface of the fastening portion. A part of the fastening portions 1a and 2a is melted at a temperature equal to or higher than the melting point of the metal, and its periphery has a temperature distribution in the range from the melting point of the metal to room temperature. In the end, it is considered that the adhesive force remained in the piezoelectric element.
[0049]
As described above, when electric resistance welding is used as a joining means for the elastic member, a large fastening force can be obtained with a small crimping force as a result. Therefore, an apparatus for joining the elastic member can be prevented from becoming large and complicated. .
[0050]
On the other hand, consider the case where this embodiment is performed by laser welding. In the case of laser welding or arc welding, unlike electrical resistance welding, the entire member cannot be instantaneously melted and the distance between the elastic members cannot be shortened. It needs to be in close contact.
[0051]
In these welding methods, melted portions are formed in order by laser irradiation. A gap is provided between the protrusion 1a and the protrusion 2a of the fastening portion, and laser light is irradiated to this gap from the side surface. The metal melted by the laser beam looks like a bridging gap and is welded in order.
[0052]
At this time, the residue in the melted portion may adhere to the piezoelectric element through the gap, and the temperature of the piezoelectric element may rise, leading to deterioration of the characteristics. This is because an inert gas such as argon is injected for preventing oxidation in the direction of laser light irradiation, so that the molten metal is scattered on the inner peripheral surface of the piezoelectric element by the force of gas injection. Further, since the solidified portion is formed by welding in order, the temperature distribution varies depending on the circumferential position of the annular welded portion, and the fastening stress generated by the heat shrinkage is uneven. As a result, unevenness occurs in the vibration displacement of the vibrator.
[0053]
In addition, it is necessary to pay attention to deterioration in characteristics of the welded portions of the elastic members 1 and 2 based on changes over time of the metal material. In particular, attention must be paid to stress corrosion cracking in austenitic stainless steels and high-strength aluminum alloys. Also in this respect, the present embodiment is excellent in that it is in an environment that is difficult to be corroded because the welded portion is in a sealed portion inside.
[0054]
The piezoelectric element, which is an electro-mechanical energy conversion element, should have as large an area as possible in order to increase driving efficiency. Therefore, it is desirable to arrange the piezoelectric element on the outer diameter side as much as possible. When an electromechanical energy conversion element is sandwiched between elastic members and fixed by a fastening portion that penetrates the inside of the element to form a vibrator, welding is performed inside the vibrator, and other than electric resistance welding This welding method is difficult.
[0055]
As a welding method other than electric resistance welding, for example, there are a laser welding method, an electron beam welding method, an arc welding method, and the like. When laser welding the fastening portion, as described above, it is necessary to irradiate the fastening portion having a gap with each other in a state where the members between the elastic members are brought into close contact with each other in advance in the axial direction from the outside. There is. Alternatively, the fastening portions are fitted to each other and the corners are welded. Therefore, welding is performed from the inside of the through hole of the elastic member, and the operation becomes difficult particularly when the vibrator is downsized. This is also true for other welding methods other than electrical resistance welding.
[0056]
Further, if welding is performed from the side surface of the fastening portion, deep welding cannot be performed and a large fastening tension cannot be withstood. In that respect, if it is an electrical resistance welding method, the fastening parts 1a and 2a can be simultaneously melted with a certain width over the entire circumference. Moreover, since it can be joined in a very short time compared to other welding methods, there is little thermal diffusion and the characteristics of the piezoelectric element are not deteriorated.
[0057]
3 is an exploded perspective view of the vibrator shown in FIG. The support plate 5 that supports the vibrator is provided with four extending portions in the radial direction, and is bent in advance to be fixed to a case to be described later. The extending portion may be bent after being assembled as a vibrator.
[0058]
In this embodiment, when an alternating voltage, which is an alternating signal, is supplied to the piezoelectric element, a standing wave due to a plurality of bending vibrations is generated on the friction surface of the vibrator, and these are combined to penetrate through the center of the elastic member. A traveling wave that rotates about the hole as a center is generated. The joint portion of the elastic member of the vibrator according to the present embodiment has a symmetrical shape with respect to the axis of the vibrator, unlike the joint portion that is joined by a bolt having a helical thread. Therefore, the vibrator is excellent in symmetry with respect to the axis, and the vibration displacement of the friction surface can be made more uniform.
[0059]
Further, as described above, the breaking strength with respect to the torsional torque of the bolt is directly proportional to the cube of the diameter of the bolt, and the breaking strength decreases rapidly when the diameter is reduced. On the other hand, the fastening tension required to maintain the adhesion of each member between the two elastic members seems to be directly proportional to the square of the diameter of the vibrator or piezoelectric element. That is, when the vibrator is made smaller, the breaking strength against the torsion of the bolt is rapidly reduced with respect to the fastening tension required for the vibrator, resulting in a problem of insufficient bolt strength.
[0060]
The force applied to the bolt when tightening the bolt is a resultant force of a force due to torsional torque in addition to the axial tension of the fastening portion. Therefore, the stress applied at the time of tightening is maximized and the bolt may be broken. In order to improve the strength of the bolt, it is conceivable to harden it by quenching. However, although the material strength of the hardened material is improved, the influence of stress concentration at the valley of the screw is increased, and brittle fracture is likely to occur.
[0061]
For these reasons, there is a limit to downsizing a vibrator that uses bolts to fasten an elastic member.
[0062]
On the other hand, in the case of the vibrator according to the present embodiment, two elastic members that are electrically resistance-welded do not need to be tightened by torsion in the first place, so that a torsional force is applied like a bolt and breaks. There is no fear of doing. Therefore, it is possible to manufacture a vibrator that is smaller than that using a bolt.
[0063]
In addition, as in the conventional example described above, in a vibrator that is tightened with elastic members from both sides of a bolt, it is difficult to apply pressure to the clamping surface of each member in advance. Since they come into contact with each other, the members may be displaced from each other.
[0064]
In that respect, as described above, electrical resistance welding requires only a small pressing force in the axial direction, so that the components do not shift in the rotational direction and can be easily assembled.
[0065]
In addition, it is conceivable to join two elastic members by adhesion instead of welding. However, since a large number of bonding surfaces are required and the manufacturing process is increased, the adhesive itself has a large vibration damping characteristic. This is also not preferable from the viewpoint of the electro-mechanical energy conversion efficiency of the vibrator.
[0066]
In this respect as well, it can be said that if the resistance welding is performed, the two elastic members are directly melted and joined, so that the vibration attenuation is not increased and a vibrator having high conversion efficiency can be configured.
[0067]
FIG. 4 is an exploded perspective view of a vibration wave driving device using the vibrator assembled in the present embodiment.
[0068]
Two rotors composed of the rotor-side friction materials 13 and 14 and the rotor main bodies 11 and 12 are in pressure contact with the coil springs 15 and 16 at both ends of the vibrator disposed in the center, respectively.
[0069]
The output shaft 21 passes through the vibrator, the rotor, and the coil spring, and is fixed to the two detents 17 and 18 by set screws 19 and 20.
[0070]
A standing wave, which is, for example, two secondary bending vibrations is generated on the friction surface of the vibrator by a voltage supplied to the piezoelectric element, and these are combined to generate a primary traveling wave. As a result, both end portions of the vibrator cause a swing motion, rotate the rotor, and rotate the output shaft fitted to the rotor.
[0071]
The displacement generated on the friction surface of the vibrator is magnified by the constriction provided on the elastic member. The rotation speed can be adjusted according to the size of the constricted portion.
[0072]
FIG. 5 shows a state when the vibration wave driving device using the vibrator of the present embodiment is housed in the case. The upper case 24 and the lower case 25 are respectively provided with bearings 22 and 23 at the center thereof to hold the output shaft. A support plate extending to the outer periphery of the vibrator is fixed between the upper and lower cases. This support plate supports a reaction force generated in the vibrator as the output shaft rotates, and prevents the vibration part and the drive part from directly contacting the inside of the case.
[0073]
The present invention is not realized only by the form of the present embodiment described above, and can be applied to various forms.
[0074]
Accordingly, other embodiments will be described below, and description will be made with a focus on differences in configuration from the above-described embodiments.
[0075]
(Second Embodiment)
FIG. 6 is a cross-sectional view of the vibrator according to the second embodiment. FIG. 7 is a partial sectional view thereof.
[0076]
The elastic member in this vibrator is composed of outer elastic members 1-1, 2-1 and inner elastic members 1-2, 2-2.
[0077]
The outer elastic members 1-1 and 2-1 are formed by pressing a plate material of austenitic stainless steel JIS standard SUS304. These outer elastic members are provided with a stepped portion on the outer peripheral side for constituting a constricted portion and a stepped portion on the inner peripheral side serving as a fastening portion. This stepped portion is formed by punching the opposite surface of the plate with a punch.
[0078]
Since austenitic stainless steel has higher ductility than martensitic stainless steel and ferritic stainless steel, it is possible to perform such a half-cutting process. If an excellent shearing surface is required, a fine blanking die may be used, and it is desirable to use a press machine for fine blanking.
[0079]
By the way, although nitriding which will be described later reduces the corrosion resistance, austenitic stainless steel containing nickel is appropriate in order to maintain a certain level of corrosion resistance. In addition, JIS standard SUS316L, which is a higher-grade stainless steel, contains molybdenum, and thus retains sufficient corrosion resistance in an everyday environment even though the corrosion resistance is reduced by nitriding. Furthermore, although press workability is slightly inferior to that of austenitic stainless steel, a kind of heat-resistant steel having a chromium content of 17% or more may be used.
[0080]
In the first place, the reason why the corrosion resistance is lowered by nitriding is that chromium and nitrogen in stainless steel are combined to form chromium nitride, so that the amount of chromium dissolved in stainless steel is reduced. If the amount of chromium in solid solution is about 13% or less even partially, such as at grain boundaries, it is difficult to form a passive film in normal air, and rust is likely to occur. Therefore, it is also effective in terms of corrosion resistance to perform nitriding using stainless steel originally containing a large amount of chromium.
[0081]
After the press working, a nitride film having a thickness of about 50 μm mainly composed of a diffusion layer is formed on the outer elastic member by ion nitriding (plasma nitriding).
[0082]
If there is a passive film that suppresses the diffusion of atoms on the surface, such as stainless steel, nitriding is usually difficult to occur, but in nitriding, nitriding proceeds while removing this passive film by sputtering, so film formation High speed is desirable.
[0083]
In addition, it seems that the production of nitrogen compounds can be controlled, and film formation with less surface roughness is possible. The formation of a nitrogen compound means that a kind of phase transformation has occurred, and as a result, a phase (or crystal grain) different from the phase (or crystal grain) generated in, for example, the original stainless steel is newly formed on the surface. It appears that the surface is rough. Even if the hardness of the base material, that is, the deformation resistance is small, if the film thickness is such a level, the film itself can withstand the stress applied to the friction contact surface, and the film does not sink.
[0084]
As the friction material, a nitrided iron-based material containing chromium is suitable. In particular, those nitrided on stainless steel were optimal.
[0085]
There are four possible reasons for this.
[0086]
First, it is possible to form a hard film having a Vickers hardness of 1000 or more. This is because chromium that is easily combined with nitrogen forms extremely hard chromium nitride.
[0087]
In addition, this chromium nitride appears to prevent metal seizure. When the same kind of materials are brought into frictional contact with each other, so-called so-called material (also called gold), generally seizure (a state in which the relative positions of the materials are fixed) is likely to occur. This is because solid diffusion occurs actively. Even if they are not the same material, generally, even when metals that form a solid solution in a full ratio or metals that have a wide solid solution range are brought into frictional contact with each other, seizure is likely to occur as in the case of materials.
[0088]
It is said that a state that is one step lighter than the occurrence of seizure is a so-called severe wear state. Severe wear is a condition in which seizure occurs partially, but the force to shear the seizure is smaller than the frictional force, and the segregation of the friction surfaces is maintained without reaching the fixed state. it is conceivable that. In the severe wear state, not only intense wear is caused, but also the friction surface becomes uneven, and stable frictional contact is not achieved.
[0089]
However, the above is a general phenomenon, and if a stable oxide film exists on the surface, direct contact between metals can be avoided, and mild wear can be maintained without causing seizure. Therefore, even in actual frictional contact between stainless steels, there is a state where the amount of wear is extremely stable and the amount of wear is small.
[0090]
In addition, when a certain amount of chromium nitride is present, not only because the nitride itself is extremely hard, but also a stable bond (for example, ionic bond or covalent bond) rather than a metal bond, Since it is in phase, it is considered that seizure hardly occurs.
[0091]
Second, a nitride film of iron-based material containing chromium has high heat resistance. The friction surface is considered to be a high temperature of several hundred degrees. This is because a blue film called bluing is actually seen on the sliding surface. This film is an oxide film formed when an iron-based material is heated to several hundred degrees. It is desirable that the hardness of the friction surface does not decrease or is low even at such a high temperature. By maintaining high deformation resistance even at high temperatures, deformation of the frictional sliding surface can be suppressed.
[0092]
Third, the necessary corrosion resistance can be obtained. As long as it is used as a friction material for a vibration wave drive device, rust is not preferred, but stainless steel can provide daily corrosion resistance. However, those nitrided on 13% chromium stainless steel are somewhat uneasy about corrosion resistance.
[0093]
In that case, although the corrosion resistance is slightly lowered by nitriding, as described above, the stainless steel containing nickel or molybdenum, the stainless steel with a chromium content of 17% or more, and the JIS standard with a particularly low carbon content to prevent sensitization By using stainless steel with the L symbol, stainless steel containing aluminum, or a material belonging to heat resistant steel, the reduction in corrosion resistance can be compensated.
[0094]
The fourth reason is that the frictional surface tends to become familiar due to initial wear. The cause is considered to be the composition distribution and phase distribution in the thickness direction of the nitride film. The nitride film is composed of a compound portion in which chromium or iron and nitride are formed in iron, and a diffusion portion in which nitrogen only penetrates into the iron lattice.
[0095]
The compound portion is considered to be composed of various chromium nitrides having different ratios of chromium and nitrogen and various iron nitrides having different ratios of iron and nitrogen. And as the surface increases, the amount of the compound increases, and the diffusion portion increases toward the inside. As a result, the harder the surface. That is, it is a kind of gradient material.
[0096]
By the way, the friction surface of the vibration wave driving device has a part where the load is partially increased in the friction surface in the initial stage. There is a place where the surface pressure becomes extremely high until the friction surfaces become familiar with each other. Such a place may cause severe wear and then the entire friction surface may be in that state.
[0097]
In that respect, the nitride film of iron-based material containing chromium is convenient because the surface has more compounds. This is because, if the amount of the compound is large, chemical wear precedes and the amount of wear is not always small, but it is easy to maintain a smooth wear state. As the wear progresses, the shape of the friction surface becomes blurred. Because the iron in the diffusion part forms an oxide film and is familiar, there is no place where the stress is large in the minute part of the surface, so the oxide film is not destroyed, and the amount of wear decreases thereafter I think that. In a layer containing a large amount of compound, chemical wear is more remarkable than hard iron forming an oxide film, but it is considered that seizure hardly occurs. Therefore, a material containing a certain amount of chromium such as stainless steel is suitable.
[0098]
In general, the term “compound layer” or “diffusion layer” may be used, but in reality, the term “a layer containing a large amount of compound” or “a layer having many portions in which the base lattice of the iron-based material is maintained” is avoided.
[0099]
As described above, stainless steel on which a hard nitride film is formed is suitable as a friction material because it has relatively good workability and has daily corrosion resistance.
[0100]
By the way, since the tip of the fastening portion is welded, it is masked so that the nitride film is not formed in consideration of the weldability. Masking is performed by inserting a fastening portion into a metal plate having a hole with a bottom. However, welding was possible if the conditions were selected even at the portion where the nitride film was formed.
[0101]
On the other hand, the inner elastic members 1-2 and 2-2 that are in direct contact with the piezoelectric element 3 were cut using free-cutting austenitic stainless steel JIS standard SUS303. This is because it has a simple annular shape, but a certain degree of accuracy is required for both end portions. In the case of manufacturing by press punching, both ends need to be lapped later, so cutting was performed in consideration of the total man-hours.
[0102]
In welding, the front ends of the fastening portions of the two outer elastic members 1-1 and 2-1 first come into contact with each other. At that time, as shown in FIG. 7, a gap S3 is formed further on the inner peripheral side of the constricted portion of the vibrator. Since the upper and lower electrodes 31 and 32 are attached to the welding machine, their positional relationship is determined in advance. In addition, since the components of the vibrator are fitted to each other, the coaxial accuracy of each component can be kept high.
[0103]
After welding, the gap S3 disappears. The contact state of the portion where the outer elastic members 1-1, 2-1 and the inner elastic members 1-2, 2-2 abut each other is important. Since this portion has a high stress in the vibration of the vibrator, if the contact state is not uniform, the characteristics of the vibrator vary. Therefore, as can be seen from FIG. 7, the inner stepped portions of the outer elastic members 1-1 and 2-1 are reversely tapered so that the outer peripheral portions first come into contact therewith. This is because the contact portion is limited only to the outer peripheral portion of the reverse taper portion to suppress variation in bending rigidity of the vibrator. In addition, there is an effect that the pressure applied to the inner peripheral side of the piezoelectric element does not become too large.
[0104]
(Third embodiment)
FIG. 8 is a cross-sectional view showing a third embodiment.
[0105]
In this vibrator, the friction surface is not an end surface, but is closer to the piezoelectric element side than both ends, that is, a surface at an intermediate position of the elastic member.
[0106]
Two constricted portions are provided in order to obtain a necessary vibration direction and a required displacement on the friction surface. A friction surface exists between the two constricted portions.
[0107]
In the first embodiment and the second embodiment, the friction surfaces of the vibrator are at both ends, and the vibration direction is a direction oriented approximately 45 ° inward with respect to the axis of the vibrator. In that respect, the friction surface of the vibrator of the present embodiment is directed to the outside by about 45 °.
[0108]
The elastic members 1 and 2 are austenitic stainless steel. After cutting JIS standard SUS303, ion (plasma) nitriding treatment was performed. Normally, the friction surface is subjected to a smoothing process such as lapping, but only cutting is performed in the present embodiment.
[0109]
In general, since the friction material is bonded to or applied to an elastic member, the friction material alone lacks flatness and smoothness, and therefore lapping is added as post-processing. However, in this embodiment, since there is a friction surface at the intermediate position of the elastic member, lapping or the like is difficult.
[0110]
In that respect, if the conditions are appropriate in the nitriding treatment, it is possible to prevent the treated surface from becoming rough or the flatness from deteriorating, so that the cutting surface can be used as it is as a friction surface. In particular, ion nitriding is desirable because it is easy to control the formation of the compound portion on the surface to be treated. This is because the portion that has undergone phase transformation into the compound often has a large surface roughness.
[0111]
As for the frictional surface portion of the elastic member, the surface accuracy obtained by the cutting process can be maintained almost as it is after nitriding. As for the friction surface, it is desirable to select a cutting tool having a large tip radius during cutting or to reduce the feed speed, select appropriate cutting conditions, and finish with good surface accuracy. Going further, you may use a batting tool or, in some cases, burnish the surface.
[0112]
(Fourth embodiment)
FIG. 9 is a cross-sectional view of the vibrator of the vibration wave driving device according to the fourth embodiment.
[0113]
This vibrator is not formed with a hole through which the output shaft passes. The elastic member 2 does not have a small-diameter portion called a constricted portion, and only the elastic member 1 has a small-diameter portion that forms a constriction.
[0114]
A fastening portion 1a having a protrusion is provided at the center of the surface of the elastic member 1 facing the elastic member 2, and the elastic member 2 is provided with a recess for fitting the fastening portion 1a on the surface facing the elastic member 1. Yes. When the fastening portion 1a is fitted into the recess of the elastic member 2, the center positions of the elastic members 1 and 2 are determined. Therefore, it is possible to perform welding while fixing the shaft centers of the elastic members 1 and 2 to an accurate position without using a jig for determining the shaft center position.
[0115]
Further, when the elastic members 1 and 2 are welded, when the piezoelectric element 3 and the flexible printed circuit board 4 are pressed by the pressing plate 30 via the support plate 5, the positions of the constituent members of the vibrator are fixed and are welded. There will be no misalignment.
[0116]
In addition, since it is desirable that an electric current does not flow into the side surface which the fastening part 1a fits, it is good to apply an insulating paint etc. to this part.
[0117]
The electrodes 31 and 32 sandwiching the elastic members 1 and 2 are merely in pressure contact with the end portions of the elastic members 1 and 2, respectively. Electric resistance welding can be performed by concentrating on the fastening portion 1a and a portion of the elastic member 2 facing the fastening portion 1a.
[0118]
(Fifth embodiment)
FIG. 10 is a cross-sectional view of the vibrator of the vibration wave driving device according to the fifth embodiment.
[0119]
The vibrator shown in FIGS. 1 to 9 has two elastic members 1 and 2 directly joined by electric resistance welding, but the vibrator shown in FIG. 10 is a separate member from the elastic members 1 and 2. The elastic members 1 and 2 are joined via a certain fastening member 8.
[0120]
In the present embodiment, a resin hollow member 26 is disposed between the fastening member 8 and the piezoelectric element 3 as a heat insulating member.
[0121]
The fastening member 8 has a flange portion, and is formed so that electric resistance welding is completed immediately after the flange portion abuts on a step provided on the inner diameter portion of the hollow elastic member 1.
[0122]
The piezoelectric element 3, the flexible substrate 4, and the support plate 5 are positioned at their central axes by a fastening member via a hollow member.
[0123]
The reason why the hollow member 26 is provided is that the piezoelectric element is protected from heat generated during welding, and at the same time, the molten dust that may be generated during welding adheres to each component, thereby causing a disadvantageous phenomenon such as a short circuit. It is also for avoidance.
[0124]
When the upper electrode 31 is brought into pressure contact with the fastening member 8 and the lower electrode 32 is brought into pressure contact with the elastic member 2 to pass a current, electric resistance welding is performed between the fastening member 8 and the elastic member 2.
[0125]
Although the elastic member 1 is not directly fixed by welding, the elastic member 1 is pressurized toward the elastic member 2 by a flange portion provided in the fastening member 8, and between the elastic member 1 and the elastic member 2. Sufficient fastening tension can be applied.
[0126]
In addition, before performing electrical resistance welding, the positional relationship of each member pinched | interposed between the elastic members 1 and 2 can be fixed by pressurizing beforehand using the pressurizing jig 34, and each member is fixed at the time of welding. It is possible to prevent the occurrence of displacement.
[0127]
Moreover, the tension remaining on the fastening member after welding can be adjusted by the magnitude of the applied pressure.
[0128]
(Sixth embodiment)
FIG. 11 is a cross-sectional view of the vibrator of the vibration wave driving device according to the sixth embodiment.
[0129]
In this embodiment, the fastening member 8 has a simple shape in which the center portions of both end faces protrude and can be formed by press working.
[0130]
Although not shown, the elastic member 1 has a concave portion at the center of the end surface, and the protrusion on the outer peripheral portion becomes a friction sliding surface. The portion of the elastic member 2 that faces the elastic member 1 is a flat surface and has a very simple shape. Therefore, both elastic members can be easily formed from a round bar by cutting.
[0131]
A vibrator is manufactured by bringing two protruding portions of the fastening member 8 into contact with the elastic members 1 and 2 and simultaneously performing electrical resistance welding.
[0132]
As in FIG. 10, the central axis of the member such as the piezoelectric element 3 sandwiched between the elastic members 1 and 2 is positioned by the fastening member 8. The electrode 31 is fitted into the recess of the elastic member 1, and the elastic member 2 is fitted into the inner peripheral portion of the collar 32-1 that is lightly fitted to the outer periphery of the electrode 32. Thereby, each member which comprises a vibrator | oscillator can be easily aligned.
[0133]
The reason why the lower electrode 32 and the collar 32-1 are separate members is that the end face of the electrode needs to be sometimes polished as maintenance.
[0134]
For this purpose, the electrode and the collar must be separable. Of course, even if it is not light fitting, the structure which provided fixation with another screw, the external thread on the outer periphery of the electrode, and the internal thread on the inner periphery of the collar may be used.
[0135]
(Seventh embodiment)
FIG. 12 is a cross-sectional view of the vibrator of the vibration wave driving device according to the seventh embodiment.
[0136]
In the present embodiment, the fastening member 8 is provided with a through hole at the center thereof, and the support pin 27 is passed through the through hole, and at the same time, the fastening member 8 is electrically resistance welded to the elastic members 1 and 2. The support pins 27 are electrically resistance welded to the elastic member 2. The vibrator is supported by fixing the tip of the support pin 27.
[0137]
A step is provided in the inner diameter portion of the hollow fastening member 8, and the flange portion of the support pin 27 contacts the step. Since the support pin 27 is fixed between the fastening member 8 and the elastic member 2 by a flange portion that is in contact with the inner diameter of the fastening member 8, there is no position shift at the time of electric resistance welding.
[0138]
The fastening member 8 is manufactured by press working, and a welded portion projection is provided by utilizing the sagging and burr at that time. The support pin 27 is processed by forging (upset), which is a kind of forging process, and the threaded portion is rolled. The entire vibration wave driving device is supported by fixing the screw portion to a base (not shown) or the like.
[0139]
Further, in this embodiment, the split electrode 31 pressed against the elastic member 1 is disposed on the side surface of the elastic member 1 so that the current flows smoothly through the welded portion.
[0140]
(Eighth embodiment)
FIG. 13 is a cross-sectional view of the vibrator of the vibration wave driving device according to the seventh embodiment.
[0141]
The fastening member 8 is a stainless steel pipe made of JIS standard SUS304.
[0142]
A step is provided in the inner diameter portion of the hollow elastic members 1 and 2, and the fastening member 8 is brought into contact with the step. Further, bearings 9 and 10 are disposed outside the end portion of the fastening member, and these are also positioned by a step provided in the inner diameter portion of the elastic members 1 and 2.
[0143]
A vibrator is formed by simultaneously performing electrical resistance welding of two elastic members to both ends of a fastening member 8 which is a stainless steel pipe.
[0144]
(Ninth embodiment)
FIG. 14 shows an example in which the vibration wave driving device using any one of the vibrators described above is mounted as a driving source for the finger portion of the robot manipulator.
[0145]
Wires and link mechanisms can be considered to move the joints of the fingers, but complex control is required when moving each joint simultaneously. This is because it is necessary to drive the joint motor of the finger part at the tip even when trying to move only another joint, for example, the joint of the arm part.
[0146]
Since the generated vibration torque is sufficiently large even if the vibration wave driving devices 61 and 62 in FIG. 14 are downsized, they can be directly mounted inside the finger portion of the robot manipulator. Each joint can be driven independently through the worm gears 41 and 42 and the worm wheels 43 and 44 by the vibration wave driving devices 61 and 62 with the joint shafts 45 and 46 as the central axes.
[0147]
Of course, if a vibration wave drive device is arranged at each joint, each joint can be driven completely independently, and each joint is not affected by the operation of other joints, so control is easy. Yes. If the axis of the vibration wave driving device is directed in the length direction of the finger, it can be efficiently arranged even in a small finger.
[0148]
(Tenth embodiment)
FIGS. 15 and 16 are obtained by mounting the vibration wave driving device using any of the vibrators described above on an electric side mirror used for visual confirmation of the rear of the automobile.
[0149]
Since the vibration wave driving device can generate a torque more than 10 times that of a conventional electromagnetic motor if it has the same size, the reduction gear can be simplified.
[0150]
Therefore, noise can be suppressed and space can be saved.
[0151]
The electric side mirror shown in FIGS. 15 and 16 is characterized in that it can slide in the vertical direction in addition to the operation of a normal retractable mirror.
[0152]
FIG. 15 shows a usage state as a normal electric side mirror, and FIG. 16 shows a usage state when the electric side mirror body is slid downward.
[0153]
The vibration wave driving device 63 performs a normal mirror retracting operation, and drives the slide table 48 fixed to the side mirror up and down by the vibration wave driving device 64, the spur gear 51 for reduction, and the lead screw 47.
[0154]
Here, a lead screw is used as the slide mechanism, but a rack and pinion system or the like may be used.
[0155]
Here, the meaning of the slide mechanism will be described. In recent automobiles, the side mirror of this embodiment, which is installed on the side of the door or in the vicinity thereof instead of the fender mirror, has become mainstream.
[0156]
However, there are many large side mirrors depending on the vehicle type, and the rearward confirmation is good, but there is a case where the side mirrors obstruct the field of view obliquely forward.
[0157]
In particular, when turning to the driver's seat (when turning right in a Japanese car), a pedestrian on the pedestrian crossing is hidden by the side mirror, which is dangerous.
[0158]
Therefore, in this embodiment, the side mirror can be slid up and down.
You can notice by actually driving the car, but even when the position of the side mirror is lowered, the door panel next to the driver's seat can see the mirror through the glass without blocking the line of sight. Can do well. Depending on the individual's height, sitting height, etc., the mirror may be moved up and down to a position that does not obstruct the oblique front view and can also secure the rear view.
[0159]
【The invention's effect】
As described above, according to the present invention, when fastening a plurality of elastic bodies of the vibrator, fastening by electric resistance welding is performed without using a fastening bolt, so that there is no micro-slip of the screw thread of the bolt, and The symmetry of the shape with respect to the axis of the vibrator can be improved. For this reason, the electrical-mechanical energy conversion efficiency of the vibrator is improved, and variation in vibration displacement of the vibrator is improved.
[0160]
In addition, when a vibration wave driving device using this vibrator is configured, the contact between the vibrator and the moving body becomes more uniform, so that the drive loss due to frictional sliding is reduced and the efficiency is increased. Uneven wear is suppressed and the life is extended. Furthermore, since the contact on the friction surface becomes uniform, the generation of abnormal noise can be suppressed.
[0161]
On the other hand, when the elastic member is joined, it is sufficient to press the elastic member with a considerably small force compared to the fastening tension of the elastic member. A vibration wave driving device can be provided.
[0162]
Furthermore, a bolt for fixing the elastic member is not necessary, and a vibrator having a simple configuration with a reduced number of parts can be configured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vibrator according to a first embodiment.
FIG. 2 is an enlarged cross-sectional view of a welded portion in the vibrator of FIG.
FIG. 3 is an exploded perspective view of the vibrator according to the first embodiment.
FIG. 4 is an exploded perspective view of a vibration wave driving device using the vibrator according to the first embodiment.
FIG. 5 is a perspective view showing a vibration wave driving device using the vibrator according to the first embodiment and a case for supporting the vibration wave driving device.
FIG. 6 is a sectional view of a vibrator according to a second embodiment.
FIG. 7 is an enlarged cross-sectional view of a welded portion in the second embodiment
FIG. 8 is a cross-sectional view of a vibrator according to a third embodiment
FIG. 9 is a sectional view of a vibrator according to a fourth embodiment.
FIG. 10 is a sectional view of a vibrator according to a fifth embodiment.
FIG. 11 is a cross-sectional view of a vibrator according to a sixth embodiment
FIG. 12 is a cross-sectional view of a vibrator according to a seventh embodiment
13 is a sectional view of a vibrator according to an eighth embodiment. FIG.
14 is a diagram for explaining a state in which a vibration wave driving device using any of the vibrators shown in FIGS. 1, 6, and 8 to 13 is mounted on a finger portion of a robot manipulator. FIG.
FIG. 15 is a diagram showing a state in which a vibration wave drive device using any of the vibrators shown in FIGS. 1, 6, and 8 to 13 is mounted on an electric side mirror of an automobile.
16 is a view showing a state in which the electric side mirror of FIG. 15 is slid downward.
[Explanation of symbols]
1, 2 Elastic member
1a, 2a Fastening part
1aa Convex
3 Electrical-mechanical energy conversion element
4 Flexible printed circuit boards
5 Support plate
6, 7 Friction member
8 Fastening member
9, 10 Bearing in vibrator
11, 12 Rotor body
13, 14 Rotor side friction material
15, 16 Pressure spring
17, 18 Non-rotating
19, 20 Set screw
21 Output shaft
22, 23 Bearing for case
24 Upper case
25 Lower case
26 Hollow resin
27 Support pin
30 holding plate
31 Upper electrode
32 Lower electrode
34 Pressure jig

Claims (22)

In a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members,
A vibrator characterized in that the plurality of elastic members are subjected to electrical resistance welding , thermally contracted, and bonded so as to apply an adhesion force to the plurality of elastic members and the electro-mechanical energy conversion element . The electro - mechanical energy conversion element is annular, the electro - at least one of the plurality of elastic members between which mechanical energy conversion element is the electro - has a projection portion on the inner diameter side of the mechanical energy conversion element The vibrator according to claim 1, wherein the protrusion and the other elastic member are joined by electric resistance welding.   The vibrator according to claim 2, wherein a gap is provided between the electro-mechanical energy conversion element and the protrusion.   4. The vibrator according to claim 2, wherein a protrusion is provided at a tip of the protrusion, and the protrusion is melted and joined by electric resistance welding.   The vibrator according to any one of claims 2 to 4, wherein the electro-mechanical energy conversion element is fitted to the protrusion.   The vibrator according to claim 5, wherein a part of the protrusion is fitted to the electromechanical energy conversion element.   The vibrator according to claim 1, wherein the electro-mechanical energy conversion element is not in contact with a portion joined by the electric resistance welding.   The vibrator according to claim 2, further comprising: a power supply substrate that contacts the protrusion between the electro-mechanical energy conversion element and the elastic member. In a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members ,
The previous SL plurality of elastic members has a fastening member is a separate member, the plurality of elastic member and the electro - and the said plurality of resilient members so as to add the adhesion to the mechanical energy conversion element fastening member And a plurality of elastic members joined through the fastening members . In a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members,
A fastening member that is a separate member from the plurality of elastic members; and the fastening member and at least one elastic member so as to apply adhesion to the plurality of elastic members and the electro-mechanical energy conversion element. A vibrator characterized by heat-shrinking by electrical resistance welding and joining the plurality of elastic members via the fastening member .   The vibrator according to claim 9 or 10, wherein the fastening member or the elastic member has a convex portion, and the convex portion is melted and joined by electric resistance welding.   The vibrator according to claim 9, wherein the electro-mechanical energy conversion element is fitted to the fastening member.   13. The vibrator according to claim 9, further comprising a power supply substrate that contacts the fastening member between the electro-mechanical energy conversion element and the elastic member.   The vibrator according to claim 9, further comprising a support member that supports the vibrator, wherein the support member and the fastening member are joined.   The vibrator according to claim 14, wherein the support member is fitted and fixed to the fastening member.   The vibrator according to claim 11, wherein the electro-mechanical energy conversion element has an annular shape, and the fastening member penetrates an inner diameter portion of the electro-mechanical energy conversion element.   A vibration wave driving device using the vibrator according to claim 1.   An apparatus having a vibration wave driving device using the vibrator according to claim 17. In a method of manufacturing a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members,
A method for manufacturing a vibrator , wherein the plurality of elastic members are subjected to electric resistance welding , heat-shrinked, and bonded so as to apply an adhesive force to the plurality of elastic members and the electromechanical energy conversion element . In a method of manufacturing a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members,
After pressurizing the fastening portion to which the plurality of elastic members are joined in the axial direction of the vibrator, the said plurality of elastic members electro - electrical said fastening portion so as to add the adhesion to the mechanical energy conversion element A method of manufacturing a vibrator , comprising: resistance welding , heat shrinking, and joining. In a method of manufacturing a vibrator in which an electromechanical energy conversion element is fixed between a plurality of elastic members,
A fastening member that is a separate member from the plurality of elastic members, and pressurizing the fastening member in a direction in which one of the elastic members is, and then closely contacting the plurality of elastic members and the electromechanical energy conversion element the one and the elastic member and the fastening member by electric resistance welding and heat-shrunk, bonded Doko manufacturing method of vibration you characterized in that to add a force. Produced from the pressure by a previous SL plurality of resilient members said fastening member, the oscillator according to claim 2 1, wherein the joining by resistance welding and the fastening member and the plurality of elastic members Method.

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