JPH06276769A - Vibrating-wave linear motor and printer - Google Patents

Abstract

PURPOSE:To remove the instability fluctuation of the pushing force of a vibrator and the instability of the contact state of a sliding part and to reduce the resistance of a constraining part caused by the pressure reaction of the vibrator without the effects of the deformation, warping and the like of a bottom plate in a vibration-wave linear motor. CONSTITUTION:The cross section of a rail-shaped stator 8, with which a vibrating elastic body 1 of a vibrator presses in contact, is made to be G shape. The elastic body 1 is brought into contact with one flange part 8A. Roller bearings 14a and 14b which are attached to a mounting stage 4, are brought into contact with another flange part. The pressure reaction of the vibrating elastic body is all received with the roller bearings 14a and 14b. A sliding bearing 12, which is coupled with a shaft 11 has an oblong shape. A bearing 12b has the round hole shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration wave motor, in particular a vibration wave linear motor of a system in which an elastic body on which a traveling wave is formed is pressed against a rail-shaped stator and the elastic body is moved along the rail-shaped stator. And a printer using a vibration wave linear motor.

[0002]

2. Description of the Related Art Conventionally, as this type of vibration wave motor,
There is one shown in FIGS. 6 and 7.

Reference numeral 1 denotes an oval elastic body made of a metal material having a protrusion 1a provided on the sliding surface side, and a piezoelectric element 2 is bonded to the upper surface thereof to form a vibrator. And
A progressive vibration wave is formed by applying an AC voltage to the piezoelectric element 2. The principle of generation of the progressive vibration wave and the structure of the piezoelectric element 2 are well known and will not be described in detail. However, the two groups of driving piezoelectric elements, which are displaced 90 degrees in position from each other, have alternating phases having a temporal phase of 90 degrees. A progressive vibration wave is formed by applying a voltage. Reference numeral 8 denotes a rail-shaped stator that makes frictional contact with the elastic body 1, is fixed to the bottom plate 10 of the motor case, and is in contact with the elastic body 1 by the pressure spring 3 via the vibration insulating material 5 (for example, felt). . Reference numeral 6 denotes a plate-shaped support plate fixed to the elastic body 1, and the center thereof is fixed by a block-shaped support body 7 to support the elastic body 1.

The elastic body 1 is supported by the mounting table 4 via the supporting plate 6 and the supporting body 7, and the mounting table 4 is in the predetermined direction B.
It is supported by a restraint member 9 that restrains displacements other than the _Y direction.

When a progressive vibration wave is formed in the elastic body 1,
The elastic body 1 moves on the rail-shaped stator 8 by the frictional force between the rail-shaped stator 8 and the elastic body 1, and the mounting table 4 and the other members 3, 5, 6, 7 are also restraining members accordingly. Move along 9 in the B _Y direction. At this time, the generated friction driving force acts on a part of the elastic body 1, and since it is deviated from the support portion, a moment acts on the elastic body 1 and tends to deviate in the B _X and B _Y directions.

The support plate 6 has an X shape as shown in FIG. 8, and the four tips are firmly joined to the inner side surface of the elastic body 1 by spot welding or the like. Further, since the central portion of the support plate 6 is firmly clamped by the support body 7 and the support body 7 is fixed to the mounting table 4, the elastic body 1 rotates even if a moment acts on the elastic body 1. It is possible to smoothly move linearly together with the mounting table 4 without rattling.

Since this motor can perform position control of intermittent drive with high accuracy, it has been proposed to be used for driving a print head in a bubble jet printer, for example, and a carriage (not shown) mounted on the mounting table 4 is used. A print head is attached to the print head, and the print head is linearly reciprocated.

[0008]

However, in the above-mentioned conventional example, the rail-shaped stator 8 and the restraining member 9 are separately processed, and these members are elongated in the B _Y direction. Therefore, the deformation of the rail and the restraint member is large, and it is difficult to accurately process the flatness of the rail sliding surface and the flatness of the mounting table of the restraint member.

Further, since the bottom plate 10 to which these rails and restraint members are attached is also a thin plate, the warp or the like is greatly deformed. When the restraint member 9 and the rails 8 are attached to this bottom plate, these members are further deformed. Become.

For this reason, the parallelism of the guide surfaces of the restraining members 9 on both sides for guiding the mounting table 4 is deteriorated, and the mounting table 4 becomes B
When moving in the _Y direction, the inclination of the mounting table 4 changes depending on the location, so the gap between the rail sliding surface of the rail-shaped stator 8 and the mounting table 4 also changes.

On the other hand, since the elastic body 1 is attached to the mounting table 4 via the supporting members 6 and 7 as described above, and the pressure spring 3 is also mounted to the mounting table 4, the rail slides. If the gap between the surface and the mounting table 4 changes depending on the location in the _BY direction, the pressure applied to the elastic body 1 fluctuates, so that a stable driving force of the motor cannot be obtained. Further, when the mounting table 4 is influenced by the guide surface of the restraint member 9 and the tilt changes depending on the place, the vibrator also tilts in conjunction, so that the contact state between the rail sliding surface and the vibrator deteriorates, and the motor performance is reduced. There was a problem of deterioration.

Further, since the restraining member 9 receives the pressure reaction force of the vibrator through the support body 7 which supports the vibrator, the restraining member 9 shown in FIG.
In such a slide bearing guide mechanism, there is a problem that the load resistance received by the moving body 4 is large and the output of the motor is reduced.

Therefore, the printing by the print head mounted on the mounting table tends to be unclear.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem, to provide a vibration wave linear motor capable of achieving stable linear drive, and to provide a printer having high printing accuracy.

[0015]

The concrete constitution for realizing the object of the present invention is as described in the claims in the claims, and is added to the rail-shaped stator. First and second guide means are provided on the movable body and the rail-shaped stator that move integrally with the vibrator that makes pressure contact, and the first guide means restrains the degree of freedom of the movable body, and the second guide means. Since the functions have been separated so as to receive the total pressure reaction force of the vibrator, there is no influence of deformation of the bottom plate or warpage,
It is possible to eliminate the fluctuation of the applied pressure of the vibrator and the instability of the contact state of the sliding portion, and to reduce the resistance of the restraint portion due to the reaction force applied by the pressure of the vibrator, thus preventing the deterioration of the motor performance.

Further, among the degrees of freedom of restraint of the moving body, the displacement in the direction parallel to the pressing direction of the vibrator is received at three points of the rolling bearing and the sliding bearing, so that the rolling bearing of the rail-shaped stator is Even if the parallelism due to the mounting error between the rolling surface and the shaft rod for the sliding bearing is poor, or the above two parallelism is deteriorated due to the warp of the shaft rod or the like, the bearings will stick together and the load resistance will increase. It is possible to prevent the motor performance from becoming large and deteriorating the motor performance.

[0017]

1 and 2 are a perspective view and a sectional view showing a first embodiment of a vibration wave linear motor according to the present invention.

In the vibrator of the vibration wave linear motor used in this embodiment, the piezoelectric element 2 is bonded to one surface of the elliptic elastic body 1 as in the conventional example shown in FIGS. A large number of comb-teeth shaped protrusions (not shown) are provided along the traveling direction of the traveling wave on the side of the driving surface opposite to the element 2.
A sheet-shaped wear-resistant material 18 is joined to the tip thereof by an epoxy adhesive or the like.

A pair of front ends of a planar U-shaped support plate 6 as shown in FIG. 6 are joined to the linear portion on the sliding surface side of the elastic body 1 by a joining means such as spot welding. The extending end portion of the support member 7 extending leftward from the mounting table 4 located at is attached to the support plate 6, and the mounting table 4 and the vibrator are integrally assembled.

A plate-like pressure spring 3 is attached between the mounting table 4 and the elastic body 1 as shown in FIG. 2B, and the tip of the pressure spring 3 and the elastic body 1 are connected to each other. Vibration insulator 5 such as felt (width 4 mm x length 20 mm x thickness 1 m)
m) and pressure plate such as stainless steel (width 4 mm x length 20 m
m) via a spring force of the pressure spring 3 via 19, a rail-shaped stator 8 which will be described later on a linear drive portion of the elastic body 1 to be driven.
It is pressed against the flange portion 8A forming the rail portion.

The rail-shaped stator 8 of this embodiment is composed of an elastic body 1.
Flange part 8 with appropriate elasticity because the straight part of
A and a flange 8B facing the flange portion 8A and configured to have higher rigidity than the flange portion 8A are formed.

On the lower surface of the rail-shaped stator 8, the shaft rod 1
The shaft rod support plates 13a and 13b supporting both ends of 1 are attached to accurate positions by a positioning pin or the like (not shown) so that the shaft rod 11 and the flange 8B of the rail-shaped stator 8 can be attached. I try to be parallel. Further, the shaft rod 11 is fixed to the shaft rod support plates 13a and 13b by a shaft rod stopper (not shown) so as not to be disengaged in the thrust direction.

Members which project from the mounting table 4 to the left in the figure at two places are provided at the front and rear in the traveling direction, and each of these members has sliding bearing members 12a and 12b made of resin or oil-impregnated metal.
(Not shown) is attached to the mounting table 4 so that the mounting table 4 can freely rotate about the A _Y direction and the shaft 11 as a central axis.
It is engaged without play.

On the other hand, in the front and rear portions of the mounting table 4 in the traveling direction, 2
Book shafts 15a, 15b are attached, and roller bearings 14a, 14 are attached to the tips of the shafts 15a, 15b.
b is rotatably attached, and the roller bearings 14a and 14b receive the reaction force of pressing the elastic body 1 by the spring 3 via the mounting table 4 and the roller shafts 15a and 15b.

The center L of the roller bearing 14 (FIG. 2a)
By adopting a structure in which the centers of the pressing forces acting on the contact portions of the elastic body 1 coincide with each other, all the pressure reaction force urging the elastic body 1 is received by the roller bearing having a small friction coefficient, and the sliding bearing is The movement resistance of the mounting table is made as small as possible by preventing the moment component of the applied pressure from being generated.

When a high-frequency electric field is applied to the piezoelectric element 2 from a power source (not shown), a progressive vibration wave is excited in the elastic body 1, and the elastic force of the elastic body 1 and the rail-shaped stator 8 is generated by the elastic body 1.
And the mounting table 4 and members attached to the mounting table 4 (3,
5,6,7,12,14,15,16,18,19)
Moves in the arrow A _Y direction along the flange 8B provided on the rail-shaped stator 8 and the shaft rod 11 attached to the rail-shaped stator 8.

At this time, the roller bearing 14 is pressed against the flange 8B of the rail-shaped stator 8 by the pressure reaction force of the elastic body 1 and rolls on the flange 8B.
Since the rotational degree of freedom of rotation is restricted, the mounting table 4 is restricted in the degree of freedom of movement other than the direction of arrow A, which is the planned movement direction, and it is possible to move smoothly in the direction of arrow A.
The mounting table 4 is provided with a position detection sensor (photointerrupter or the like) not shown, and the shaft support plate 13a,
The position and speed of the mounting table 4 are detected via the slit plate 17 attached to 13b and given an appropriate tension by a plate spring (not shown) or the like, and this signal is fed back to a control circuit (not shown). 4 speed control and stop position control are performed.

A second embodiment of the present invention is shown in FIG. 4, in which (a) is a side view and (b) is a sectional view of (a).

In the first embodiment, the rail-shaped stator 8 has a substantially G-shaped cross section, and the opposing flanges 8A, 8 are formed.
The inside of B is the sliding surface of the elastic body and the shaft bearing surface of the roller bearing, but in the present embodiment, the cross-sectional shape of the rail-shaped stator 8 is a U-shape having a groove on one side, The rail-shaped stator is sandwiched between the elastic body 1 and the roller bearing 14 from the outside of the two facing flanges 8A and 8B forming the groove.

In this embodiment, the plain bearings 12a and 12a are
2b is a round hole shape, which engages with the shaft rod 11 without backlash, and the rolling bearing 14 is substantially in the center of the sliding portion of the elastic body 1 (A _Y direction).
One for providing a bearing 12a, 12b and the flexibility of A _X-direction of the table 4 at three points of the bearing 14 is restrained, A _Z-direction is a structure for restraining the bearing 12a, 12b.

Further, in the structure of this embodiment, the sliding shaft rod 11
Are arranged inside the two flanges 8A and 8B of the rail-shaped stator 8 to reduce the width of the entire motor unit.

Although the bearing 12 is a slide bearing in the present embodiment as described above, it may be a linear ball bearing or the like, and the rolling bearing 14 may be a radial ball bearing.

The vibration wave linear motor in each of the above embodiments can be used as a printer by providing a carriage on the mounting table and mounting a print head in, for example, a bubble jet printer on the carriage.

[0034]

As described above, according to the present invention, the pressing force of the vibrator can be kept constant without being influenced by the warp of the bottom plate or the rail, and the vibrator and the rail shape can be adjusted depending on the position in the moving direction. There is an effect that a stable motor output can be obtained without changing the contact state with the stator.

Further, the first restrained member and the first restraint member, which are the slide bearing and the slide shaft rod inserted into the slide bearing, are so structured that the reaction force applied by the vibrator is not applied to the first restrained member. It has the effect of reducing bearing loss and improving motor performance.

[Brief description of drawings]

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

2A and 2B are sectional views of FIG. 1, in which FIG. 2A is a sectional view including a roller bearing, and FIG. 2B is a sectional view showing a vibrating elastic body pressing mechanism.

FIG. 3 is a perspective view showing a main part of FIG.

FIG. 4 shows a second embodiment, (a) of which is a side view,
(B) of the same figure shows a sectional view of (a).

FIG. 5 is a diagram showing a mounting structure of a vibrator according to the first embodiment.

FIG. 6 is a diagram showing a conventional vibration wave linear motor.

FIG. 7 shows a plan view of FIG.

FIG. 8 is a plan view showing the vibrator support plate of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Elastic body 2 ... Piezoelectric element 3 ... Pressing spring 4 ... Mounting table 5 ... Vibration insulator 6 ... Elastic body support plate 7 ... Support body 8 ... Rail-shaped stator 9 ... Restraint member 10 ... Bottom plate 11 ... Shaft rod 12 ... Sliding bearing 13 ... Shaft rod support plate 14 ... Roller bearing 15 ... Roller shaft 16 ... Roller bearing retainer 17 ... Linear encoder slit plate 18 ... Vibrator friction material 19 ... Pressure plate 20 ... Rail support plate 21 ... Bottom plate

Front page continued (72) Inventor Shinji Yamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshiaki Harada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Mitaka Okamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. An electro-mechanical energy conversion element is joined to a vibration elastic body formed in a loop shape, and a drive signal is applied to the electro-mechanical energy conversion element to advance to the drive surface of the vibration elastic body. Oscillator that forms a sex vibration wave, a rail-shaped stator that comes into contact with the driving surface of a vibrating elastic body of the oscillator, and is attached to the oscillator and moves along with the oscillator along the rail-shaped stator. The moving body includes a moving body, a pressing unit that presses the vibrator against the rail-shaped stator, and a guide unit that guides the moving body in a predetermined moving direction. In a vibration wave linear motor for moving a moving body in a predetermined moving direction along the rail-shaped stator, the guiding means is provided on the moving body side and restrains the moving body from moving at least one degree of freedom other than in the planned direction. Slip axis And a first guide means having a sliding shaft rod engaged with the slide bearing and fixed to the rail-like stator, a rolling bearing attached to the moving body, and an integral body with the rail-like stator. Second guide means having a rolling surface of a rolling bearing that is provided in a specific manner, and the displacement of the moving body in a direction parallel to the vibrating body pressing direction of the moving body is controlled by the first and second guide means. A vibration wave linear motor that is constrained at three points inside. 2. A vibration wave linear motor according to claim 1, wherein each of the two rolling bearings and each of the sliding bearings having a round hole has two sliding bearings, and one of the sliding bearings has an elongated hole. 3. A vibration wave linear motor according to claim 1, wherein one rolling bearing is provided and two sliding bearings are provided. 4. A printer, wherein the moving body in the vibration wave linear motor according to claim 1, 2 or 3 is provided with a printing unit.