JP2010071436A - Shaft bonding method, and method of manufacturing vibrating type driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a vibrating type driving device that can reduce creeping-up of an adhesive to a vibrating shaft. <P>SOLUTION: The vibrating type driving device 1 includes an electromechanical conversion element 2 expanded/contracted when voltage is applied thereto; the vibrating shaft 3 bonded at one end to the electromechanical conversion element 2 and axially displaced by the expansion/contraction of the electromechanical conversion element 2; and a friction engaging member 4 frictionally engaged with the vibrating shaft 3 in a slidingly displaceable manner. In the method of manufacturing the vibrating type driving device 1, the vibrating shaft 3 is bonded to the electromechanical conversion element 2 by applying the adhesive to the end face of the electromechanical conversion element 2, spraying compressed gas to the adhesive to spread out the adhesive, arranging the vibrating shaft 3 on the spread adhesive, and hardening the adhesive. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of bonding a shaft and a method of manufacturing a vibration type driving device.

  When the shaft-like member is bonded vertically to the bonding surface, a phenomenon called scooping up in which the adhesive wraps around the side surface of the shaft is observed. In particular, when a thin shaft is bonded, it is difficult to control the amount of adhesive, and excess adhesive protrudes around the shaft, forming a scooping on the side of the shaft.

  The scooping up of the adhesive shortens the effective length of the shaft. For example, in a vibration-type drive device that vibrates a vibration shaft with an electromechanical transducer and slides and displaces a friction engagement member that frictionally engages the vibration shaft, the friction engagement member is caused by the scooping up of the adhesive on the vibration shaft. There arises a problem that the movable range of is narrowed.

  There is a technology to reduce the creeping up of the adhesive to the shaft by spreading the adhesive discharged from the syringe etc. on the adhesive surface with a jig, but because the adhesive adheres to the jig, There is a problem in that the amount of adhesive applied varies and defective products with insufficient adhesive strength are generated.

Further, in Patent Document 1, in order to prevent the adhesive from creeping up on the vibration shaft of the vibration type driving device, the end surface of the electromechanical transducer is made smaller than the end surface of the vibration shaft, and the adhesive is applied to the electric machine. An invention is described which crawls up to the conversion element side. However, when a shaft having a very small cross-sectional area is bonded or when a shaft is bonded to a plate surface of a thin plate, it is difficult to make the bonding surface smaller than the end surface of the shaft.
Japanese Patent Laid-Open No. 2007

  In view of the above problems, the present invention provides a method for bonding a shaft and an adhesive to a vibration shaft that can reduce the creeping of the adhesive to the shaft when the shaft is bonded to an adhesive surface wider than the end surface of the shaft. It is an object of the present invention to provide a method of manufacturing a vibration type driving device that can reduce the creeping of the sway.

  In order to solve the above problems, a method of adhering a shaft according to the present invention on an adhesive surface is provided with an adhesive on the adhesive surface, and a compressed gas is blown over the adhesive to spread the adhesive, The shaft is disposed on the adhesive surface to cure the adhesive.

  According to this method, since the adhesive is preliminarily spread on the adhesive surface by the compressed gas, the thickness of the adhesive is small, and the adhesive protrudes from the end surface of the shaft when the shaft is pressed against the adhesive surface. The amount of adhesive that crawls to the side is small.

  In addition, according to the present invention, an electromechanical transducer that expands and contracts when a voltage is applied, and a vibration shaft that is bonded at one end to the electromechanical transducer and is displaced in the axial direction by the expansion and contraction of the electromechanical transducer A method of manufacturing a vibration type drive device having a friction engagement member that frictionally engages the vibration shaft so as to be slidably displaceable includes bonding the vibration shaft to the electromechanical conversion element on an end surface of the electromechanical conversion element. A method comprising the steps of placing an adhesive, spraying a compressed gas on the adhesive to spread the adhesive, placing the vibration shaft on the spread adhesive, and curing the adhesive. .

  According to this method, since the vibration shaft is arranged after the adhesive is pushed and spread on the end face of the electromechanical conversion element by the compressed gas, there is little scooping of the adhesive onto the vibration shaft, and the movable range of the friction engagement member is reduced. Can provide a wide vibration type driving device.

  Moreover, in the manufacturing method of the vibration type drive device of the present invention, the compressed gas may be sprayed until the adhesive wraps around the side surface of the electromechanical transducer.

  According to this method, the adhesive strength between the adhesive and the electromechanical conversion element can be increased by spreading the adhesive to the side surface of the electromechanical conversion element.

  In the method for manufacturing the vibration type driving device of the present invention, a bleed-out preventing agent may be applied in advance to the side surface of the electromechanical transducer.

  According to this method, it is possible to prevent the adhesive additive from bleeding out on the surface of the electromechanical conversion element and hindering the wiring to the electrode of the electromechanical conversion element.

  Moreover, in the manufacturing method of the vibration type drive device of the present invention, the pressure of the compressed gas may be increased stepwise.

  According to this method, when an adhesive having a low viscosity is used, it is possible to prevent the adhesive from being scattered by the compressed gas, to keep the amount of the adhesive constant, and to prevent variations in adhesive strength.

  As described above, according to the present invention, since the shaft is arranged after spreading the spread adhesive on the adhesive surface with compressed gas, the thickness of the adhesive is small, and the amount of adhesive that protrudes around the shaft is also reduced. Since there are few, the creeping of the adhesive to the side of a shaft can be controlled.

  Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic view showing a method for manufacturing the vibration type driving device 1 of the first embodiment of the present invention. The vibration type driving apparatus 1 according to the present embodiment has a piezoelectric element (electromechanical conversion element) 2 that expands and contracts when a voltage is applied, and one end bonded to an end surface (adhesion surface) of the piezoelectric element 2 in the expansion and contraction direction. The vibration shaft 3 is displaced in the axial direction by the expansion and contraction of 2 and the friction engagement member 4 is frictionally engaged with the vibration shaft 3 so as to be slidable.

  The manufacturing equipment used for the manufacture of this embodiment includes a plurality of holders 5 that hold the piezoelectric element 2 and move in the direction of the arrow in order, and an adhesive that drops an adhesive (for example, a thermosetting epoxy resin having a viscosity of 36500 cps). The agent dispenser 6 and the air dispenser 7 which ejects compressed air are provided. Each of the adhesive dispenser 6 and the air dispenser 7 includes, for example, a syringe 8 having a capacity of 10 cc, and a needle 9 having an inner diameter of 0.4 mm, for example, attached to the tip of the syringe 8. For example, compressed air of 0.03 MPa is supplied from the compressed air reservoir 11.

  First, the piezoelectric element 2 on the holder 5 is positioned directly below the adhesive dispenser 6. Therefore, the electromagnetic valve 10 of the adhesive dispenser 6 is opened for a predetermined time (for example, 1 second), and a predetermined amount of adhesive is dropped by air pressure and placed on the end face of the piezoelectric element 2. Subsequently, the holder 5 that holds the piezoelectric element 2 to which the adhesive has been dropped is moved directly below the air dispenser 7. Therefore, the electromagnetic valve 10 of the air dispenser 7 is opened for a predetermined time (for example, 1 second), and compressed air (other gas may be sprayed) is applied to the piezoelectric element 2 from above the dropped adhesive. Thereby, the adhesive is preferably spread to such an extent that it slightly wraps around the side surface of the piezoelectric element 2.

  Then, the holder 5 is moved, and the piezoelectric element 1 with the adhesive spread is transferred to a supply device for the vibration shaft 3 (only the arm 12 that holds the vibration shaft 3 is shown). Therefore, the arm 12 is disposed so that the vibration shaft 3 is pressed vertically on the piezoelectric element 2 and on the adhesive spread on one end thereof. At this time, the adhesive slightly crawls up to the side surface of the vibration shaft 3 due to wettability. Then, while holding the vibration shaft 3 on the piezoelectric element 2 by the arm 12, the holder 5 is moved into the heating furnace 13 to heat and cure the adhesive. Finally, the vibration type driving device 1 is manufactured by engaging the friction engagement member 4 with a frictional force so that the adhesive is cured and fixed to the piezoelectric element 2 so as to be slidably displaced.

  According to the present embodiment, the adhesive dispenser 6 drops the adhesive onto the end face of the piezoelectric element 2, and the adhesive in a state of being spread is pushed out by the compressed air blown by the air dispenser 7. Thereby, the thickness of the adhesive of the part to which the vibration shaft 3 is bonded is reduced, and the amount of the adhesive that rises to the side surface of the vibration shaft 3 is reduced when the vibration shaft 3 is pressed. As a result, in the vibration type driving apparatus 1 of the present embodiment, the friction engagement member 4 can move to the vicinity of the piezoelectric element 2, and the stroke is long.

  Further, in the present embodiment, the adhesive is spread with compressed air so as to wrap around the side surface of the piezoelectric element 2. Thereby, the adhesive strength between the adhesive and the piezoelectric element 2 can be increased, and peeling of the adhesive can be prevented. As a result, the vibration type driving device 1 manufactured according to the present embodiment has high impact resistance and few failures.

  In the present embodiment, it is preferable to apply a bleed-out preventing agent to the side surface of the piezoelectric element 2. In general, the piezoelectric material is exposed on the side surface of the piezoelectric element 2, and as it is, the exudation (bleed out) of the additive from the adhesive that has entered the portion by capillary action is promoted. Since the electrode of the piezoelectric element 2 is usually provided on the side surface, the bleed-out may make it difficult to connect the lead by soldering or the like to the electrode. For this reason, it is desired to suppress the bleed-out of the adhesive by applying the bleed-out preventing agent and ensure the wiring property.

  FIG. 2 shows an example of the vibration-type driving device 1 manufactured according to the present embodiment in which the distribution of the adhesive strength between the piezoelectric element 2 and the vibration shaft 3 is expanded with compressed air, and the adhesion in the arranged state. A conventional example of the vibration type driving device 1 manufactured by a conventional method in which the vibration shaft 3 is arranged and bonded from above the agent will be described.

  When stress is applied between the piezoelectric element 2 and the vibration shaft 3, the adhesive is peeled off from the piezoelectric element 2. In the conventional example, the breaking strength is about 0.8 kgf, but the present invention is carried out. In form, it was improved to about 1.05 kgf. This is an effect that the adhesive is wrapped around the side surface of the piezoelectric element 2 by blowing compressed air.

  FIG. 3 shows an example of the vibration type driving device 1 manufactured according to the present embodiment in which the distribution of the creeping amount (distance) of the adhesive to the vibration shaft 3 is spread with the compressed air. A conventional example of the vibration type driving device 1 manufactured by a conventional method of arranging and vibrating the vibration shaft 3 from above the adhesive in a state will be described.

  In the conventional example, the average value of the creeping amount of the adhesive was about 1.2 mm, whereas in the example of the present invention, the average value of the creeping amount of the adhesive was reduced to about 0.4 mm. It was. In other words, in the present embodiment, the amount of the scooping up of the adhesive can be reduced to about one third compared with the conventional manufacturing method, and the stroke of the friction engagement member 4 can be increased by about 0.8 mm.

  FIG. 4 shows an example of the vibration type driving device 1 manufactured according to the present embodiment in which the distribution of the weight of the adhesive cured on the piezoelectric element 2 is expanded with compressed air, and the installed adhesive. A conventional example of the vibration type driving device 1 manufactured by a conventional method of spreading by a jig will be described.

  In the conventional method, the adhesive adheres to the jig and a part of the adhesive is removed from the top of the piezoelectric element 2, or the adhesive attached to the jig is further added to the piezoelectric element 2. To do. For this reason, the weight of the adhesive finally cured to fix the vibration shaft 3 is only about half of the initially placed weight, or about twice the weight of the initially placed weight. Some of them have become large variations. However, in this embodiment, such a variation in the mass of the adhesive was not observed at all.

  Next, FIG. 5 shows a manufacturing method of the vibration type driving apparatus 1 according to the second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In the present embodiment, in addition to the compressed air reservoir 11, a low-pressure compressed air reservoir 15 capable of supplying compressed air having a lower pressure (for example, 0.01 MPa) than the compressed air reservoir 11 to the air dispenser 7 is used via the electromagnetic valve 14. To do.

  In the present embodiment, the air dispenser 7 first opens the electromagnetic valve 14 and supplies the low-pressure compressed air supplied from the low-pressure compressed air reservoir 15 to the piezoelectric element 2 in which the adhesive is placed on the end surface by the adhesive dispenser 6. Blow air for a predetermined time. Then, the electromagnetic valve 14 is closed and simultaneously the electromagnetic valve 10 is opened, and high-pressure compressed air supplied from the compressed air reservoir 11 is blown for a predetermined time.

  In the present embodiment, since the adhesive is first spread by low-pressure compressed air, it is difficult for the adhesive to scatter or become unbalanced. Then, the adhesive that has been spread to some extent by the low-pressure compressed air is further spread by the high-pressure compressed air until it wraps around the side surface of the piezoelectric element 2, thereby suppressing creeping of the adhesive to the vibration shaft 3. At the same time, the adhesive strength of the adhesive to the piezoelectric element 2 can be increased.

  In the above embodiment, the adhesive dispenser 6 and the air dispenser 7 are composed of the syringe 8 and the needle 9 having the same shape. However, this was simply selected to use existing manufacturing equipment and reduce the amount of line change work. Therefore, the adhesive dispenser 6 and the air dispenser 7 may be completely different from each other, and need not share the compressed air reservoir 11. For example, the adhesive dispenser 6 and the air dispenser 7 may be configured to extrude adhesive or air from a syringe with a piston driven by an actuator without using compressed air.

  Moreover, although the above embodiment demonstrated the manufacturing method of a vibration type drive device, this invention is widely applicable when adhere | attaching a shaft-shaped member on a flat adhesion surface.

  Furthermore, the adhesive used in the present invention is not limited to a thermosetting type, and may be, for example, a photo-curable adhesive, or may wait for the adhesive to naturally cure while holding the shaft. .

Schematic of the manufacturing method of the vibration type drive device of 1st Embodiment of this invention. The frequency distribution diagram which shows distribution of the adhesive strength in the Example of a vibration type drive device of FIG. 1, and a prior art example. FIG. 2 is a frequency distribution diagram showing a distribution of a creeping amount of the adhesive in the embodiment of the vibration type driving device of FIG. 1 and a conventional example. The frequency distribution diagram which shows distribution of the mass of the adhesive agent in the Example of a vibration type drive device of FIG. 1, and a prior art example. Schematic of the manufacturing method of the vibration type actuator of 2nd Embodiment of this invention.

Explanation of symbols

1 ... Vibration type driving device.
DESCRIPTION OF SYMBOLS 2 ... Piezoelectric element 3 ... Shaft member 4 ... Friction engagement member 5 ... Holder 6 ... Adhesive dispenser 7 ... Air dispenser 8 ... Syringe 9 ... Needle 10 ... Electromagnetic valve 11 ... Compressed air reservoir 12 ... Arm 13 ... Heating furnace 14 ... Solenoid valve 15 ... Low pressure compressed air reservoir

Claims (5)

A method of adhering a shaft on an adhesive surface,
Placing an adhesive on the adhesive surface,
A compressed gas is blown over the adhesive to spread the adhesive,
A method for bonding shafts, wherein the shaft is disposed on the bonding surface and the adhesive is cured. An electromechanical conversion element that expands and contracts when a voltage is applied, a vibration shaft that is bonded to the electromechanical conversion element at one end and is displaced in the axial direction by the expansion and contraction of the electromechanical conversion element, and is slidable to the vibration axis In a manufacturing method of a vibration type drive device having a friction engagement member for friction engagement,
Adhesion of the vibration shaft to the electromechanical conversion element is performed by placing an adhesive on the end surface of the electromechanical conversion element, blowing a compressed gas on the adhesive to spread the adhesive, and spreading the adhesive. A method of manufacturing a vibration type driving device, wherein the vibration shaft is disposed on the adhesive and the adhesive is cured.   The method for manufacturing a vibration type driving device according to claim 2, wherein the compressed gas is sprayed until the adhesive wraps around a side surface of the electromechanical transducer.   The method for manufacturing a vibration type driving device according to claim 3, wherein a bleed-out preventing agent is applied in advance to a side surface of the electromechanical conversion element.   The method of manufacturing a vibration type driving device according to claim 2, wherein the pressure of the compressed gas is increased stepwise.

Images