JPH03104512A - Tapping machine - Google Patents

Abstract

PURPOSE:To eliminate a power converting mechanism and permit high accuracy and large output by using a main axis to which a tap is provided and an ultrasonic vibrator including a machine resonator for making a tap vibrate approximate elliptically. CONSTITUTION:A main axis 35 is supported on a tapping machine 31 in reciprocating linear drivably via linear bearings 33 and 34. A case 36 housing an ultrasonic vibrator 11 is mounted on the main axis 35, and a driving part 41 formed on the ultrasonic vibrator 11, a pressing bolt 37, and a tap 40 pressedly fixed with a roller 38 are abutted to the case 36. Moreover a motor 42, giving an vertical feeding action via a roller 43 for power transmission, is arranged on the side surface of the main axis 35. When A.C. voltage is applied to the vibrator 11, an approximate elliptical vibration is excited, and the tap 40 is directly driven by the friction force of the driving part 41 and the tap 40 to process a work piece 45 on a processing base 44 under the driving action of the motor 42. This obtains a tapping machine having simple structure, excellent accuracy, and good responsiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tapping machine that forms a screw hole in a workpiece by rotating a tap while giving a feed motion, and particularly relates to a driving source for the rotation motion of the tap. It is related to.

[Prior Art] In tubbing processing, a main shaft with a tap attached thereto is simultaneously driven to feed and rotated, and the amount of drive of both is synchronized to perform processing.

Conventionally, the rotational drive of the main shaft described above is achieved by transmitting the driving force of a rotary electromagnetic motor disposed outside the main shaft via a power transmission mechanism such as a pulley or a belt. Therefore, a special vertical feeding mechanism is provided to enable the main shaft to be vertically fed while applying rotational driving force.

[Problems to be Solved by the Invention] However, the above-mentioned tubbing machine requires a power transmission mechanism and a vertical feed mechanism in the parts that bear the most load, so it is difficult to increase the rigidity, and it is difficult to increase the rigidity and reduce failures. It was difficult to standardize the rate.

Furthermore, it was difficult to improve machining accuracy and manufacturing costs were high.

The present invention has been made to solve the above-mentioned problems, and does not require a power conversion mechanism or a vertical feed mechanism, has a simple structure, can easily achieve high precision, and has a large output. The purpose is to obtain an excellent tapping machine that is capable of

Furthermore, the purpose is to obtain a tubbing man with excellent responsiveness by using a ZLR that directly drives only the taps.

[Means for Solving the Problems] In order to achieve this object, the tapping machine of the present invention includes a main shaft capable of reciprocating linear drive, a tap attached to the main shaft, and a tap attached to the front main shaft. In a tapping machine equipped with a holding means for setting the tap and a drive source for rotating the tap, an ultrasonic vibrator including a mechanical resonator including a mechanical resonator having a vibration part that performs approximately elliptical vibration is used as the drive source, and the tap is rotated. The ultrasonic vibrator is attached to the main shaft, and includes crimping means as the holding means for crimping the tap to the ultrasonic vibrator.

[Effect]

In the tapping machine of the present invention having the above configuration, when an alternating current electric signal is applied to the ultrasonic vibrator that obtains a mechanical output using a piezoelectric phenomenon, a substantially elliptical vibration with minute amplitude is excited at a predetermined portion of the ultrasonic vibrator.

When a tap, which is a driven body, is pressed against the vibrating portion of the ultrasonic transducer, the tap receives a driving force caused by the frictional force, and is directly driven and rotated in a predetermined direction.

Further, when the ultrasonic vibration is not driven, the tap is strongly held by the pressing force.

[Example] Hereinafter, examples embodying the present invention will be described with reference to the drawings.

The piezoelectric actuator used in the present invention can be used, for example, in Japanese Patent Application No.
An ultrasonic transducer including a mechanical resonator as proposed in the specification and drawings attached to the application of Japanese Patent No. 46866 may be used.

An example of the configuration will be described below with reference to FIG.

The ultrasonic transducer 11 includes an elastic body 21 having a rectangular flat plate shape.
A first piezoelectric body 22 for exciting bending vibration in the elastic body 21 is attached to the upper surface of the elastic body 21 .

In the elastic body 21, second piezoelectric bodies 23a and 23b for exciting longitudinal vibration in the elastic body 21 are attached to the side surfaces substantially orthogonal to the mounting surface.

The longitudinal center of the elastic body 21 is fixed by fixing bolts 24a and 24b for fixing the elastic body 21. The other ends of the fixing bolts 24a and 24b are
It is fixed to bases 25a and 25b.

An electrode 26 is provided on the upper surface of the first piezoelectric body 22 . Further, electrodes 27g and 27b are provided on the upper surfaces of the second piezoelectric bodies 23a and 23b. Further, the elastic body 21 itself also serves as a ground electrode, and the elastic body is connected to the bases 25a and 25 through the fixing bolts 24a and 24b.
It is grounded to 5b.

Further, the elastic body 21 bends in a secondary mode at both free ends at a predetermined frequency f in the thickness direction, and longitudinally vibrates in a primary mode at both free ends in the length direction at the same frequency f. The shape and dimensions have been adjusted.

Generally, the resonant frequency of longitudinal vibration propagating in an elastic body depends on the length of the elastic body. Further, the resonance frequency of bending vibration in the thickness direction of the elastic body depends on the length and thickness. Therefore, since it is easy to design the elastic body 21 as described above, the details thereof will be omitted.

The operation of the ultrasonic transducer 11 configured as above will be explained below.

First, when an alternating current voltage of frequency f is applied to the first piezoelectric body 22 to cause it to vibrate, the ambiguous body 21 resonates in the secondary mode of bending vibration and a standing wave is excited.

Next, when an alternating current voltage of frequency f is applied to the second piezoelectric bodies 23a and 23b to cause them to vibrate, the elastic body 21 vibrates in the first mode of longitudinal vibration and a standing wave is excited. In other words, the positions fixed by the fixing bolts 24a and 24b are the nodes of each standing wave.

At this time, by adjusting the amplitude and phase of the voltages applied to the first piezoelectric body 22 and the second piezoelectric bodies 23a and 23b, it is possible to generate approximately elliptical vibration of an arbitrary shape in the elastic body 21. .

In the above embodiment, an ultrasonic vibrator that excites the first-order mode of longitudinal vibration and the second-order mode of bending vibration and generates approximately elliptical vibration by combining them is described, but the present invention is not limited to this, and Various vibration modes such as , bending vibration, shear vibration, and torsional vibration can be used, and higher-order modes may also be used.

FIGS. 2 and 3 show the configuration of a tubbing machine 31 that suitably utilizes the ultrasonic transducer 11 described above. In this figure, each member labeled with the same reference numeral as in FIG. 1 is the same as each component described in detail above.

In the tapping machine 31, a main shaft 35 is supported by linear bearings 33 and 34 attached to a main body 32 so as to be movable up and down. The ultrasonic transducer 11 is housed in a case 36 at the lower end of the main shaft 35, and a tap 40 is crimped onto the ultrasonic transducer l1 by a crimping mechanism composed of a crimping bolt 37, a roller 38, and a roller support 39. has been done.

The ultrasonic transducer 11 has driving parts 41 formed at both ends where the maximum amplitude is obtained, and the tap 40
It is in contact with.

On the other hand, a rotary motor 42 is disposed on the side surface of the main shaft 35, and its driving force is transmitted to the main shaft 35 by a power transmission roller 43, so that the main shaft 35 is moved up and down.

Furthermore, the ultrasonic vibrator 11 and the rotary motor 42
The input terminal of is connected to a control device (not shown).
By operating these both in synchronization, the workpiece 45 placed on the processing table 44 below the tap 40 is controlled to be processed.

In the tapping machine 31 configured as described above, when an alternating current voltage of the predetermined frequency is applied to the ultrasonic vibrator 11, a substantially elliptical vibration with a minute vibration amplitude of about 10 to 10 is excited. Ru.

As a result, the tap is directly driven in the forward and reverse directions of arrow A in the figure by receiving a driving force caused by the frictional force between the driving portion 41 and the tab 40. On the other hand, when the power to the ultrasonic vibrator 11 is cut off, the tap 40 is strongly held and does not move because it receives a force several times the driving force due to the crimping force generated by the crimping bolt 37. . Furthermore, when replacing the tap 40, if only the first piezoelectric body 22 of the ultrasonic transducer 11 is excited, the tap 40 can be replaced.
Since a buoyancy force is applied to the tap 40, the tap 40 can be easily replaced without changing the pressing force.

By using 13f having the above-described configuration, it is possible to obtain an excellent tapping machine that is simple in structure and easy to improve accuracy without requiring a power conversion mechanism or a special vertical feed mechanism.

Insulation and reliability can also be improved by forming or coating the driving part 41 formed on the ultrasonic transducer 11 with a wear-resistant material such as ceramics.

The ultrasonic vibrator used in the above-mentioned tapping machine is
It has the following advantages compared to conventional electromagnetic motors.

1) Since no winding is required and the structure is simple, it can be made smaller and lighter.

2) High energy conversion efficiency can be obtained; for example, the output/volume ratio and output/weight ratio are 10 times or more compared to a DC motor.

3) Since it uses frictional force, it has excellent responsiveness and controllability.

4) Does not generate magnetic or electromagnetic noise.

Furthermore, although an example in which the ultrasonic transducer is shaped like a flat plate has been described, it is also possible to use various shapes such as a disk shape, a cylindrical shape, an annular shape, a rod shape, and a rectangular shape.

In addition, various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, a power conversion mechanism or a special vertical feed mechanism is not required, and as a result, a tubbing with a simple structure and excellent responsiveness can be achieved. machine can be realized.

[Brief explanation of drawings]

1 to 3 show embodiments embodying the present invention. FIG. 1 is a top view of an ultrasonic transducer used in the present invention, and FIG. 2 is a top view of a tapping machine to which the present invention is applied. FIG. 3 is a side view showing the whole, and a partially cutaway enlarged view showing a part of FIG. 2 on an enlarged scale. In the figure, 11 is an ultrasonic transducer, 21 is an elastic body, and 22 is a first
A piezoelectric body, 23a and 23b are second piezoelectric bodies, 35 is a main shaft, 3
7 is a pressure bolt, 38 is a roller, 39 is a roller supporter,
40 is a tap.

Claims (1)

[Claims] 1. A main shaft (35) capable of reciprocating linear drive;
); a holding means for attaching the tap (40) to the main shaft (35); and a driving source for rotating the tap (40). , an ultrasonic vibrator (1
1), the ultrasonic transducer (11) is connected to the main shaft (35
), and the tap (40) serves as the holding means.
crimping means (for crimping the ultrasonic transducer (11))
37, 38, 39). 2. The tapping machine according to claim 1, wherein the ultrasonic vibrator includes an elastic body (21), and electromechanical transducer elements (22, 23a, 23b) that generate ultrasonic vibrations when an AC electric signal is applied. ) is attached to the elastic body (21), and the electromechanical transducer (22, 23a, 23b)
A tapping machine characterized in that standing wave vibrations are excited in at least two directions substantially orthogonal to a predetermined vibration part by driving the machine.