JPH11295013A - Measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring instrument which can detect the dimension of an object to be measured with high accuracy. SOLUTION: A reciprocating member 21 is attached to a guide rail 15 fixed to a supporting frame body 10, in such a state that the member 21 can make reciprocating motions in the direction of a straight line and a mobile-side measuring piece 32 which holds an object to be measured put between the piece 32 and a fixed-side measuring piece 31 provided to the end section of the frame body 10 and is attached to the member 21. In addition, an ultrasonic oscillator 24 having a vibrating body which comes into contact with the frictional rail 11 of the frame body 10 is attached to the member 21 and magnetic heads 34 and 35 which electromagnetically detect the magnetic pattern of a magnetic scale 33 that is attached to the frame body 10 and constituted of a ferromagnetic material are attached to the member 21. The dimension of the object to be measured can be measured when the object is put between the mobile-side measuring pieces 32 driven by means of the ultrasonic vibrator 24 and the fixed-side measuring piece 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device for measuring a distance such as the length of an object using a linear ultrasonic motor.

[0002]

2. Description of the Related Art Various measuring devices are used for measuring dimensions and distances such as length and width of an object to be measured. When measuring the dimensions of a product having a relatively small size, such as parts of various industrial products, it is necessary to be able to perform the operation efficiently. As a device that measures such components with high accuracy as an object to be measured, there is a case where laser light etc. is irradiated on the object to be measured and dimensions are measured from the position of reflected light etc. Is an expensive measuring device.

[0003]

When an object is measured manually by an operator, there are a nozzle, a manometer, etc., and the scale is read by sandwiching the object between two measuring pieces. However, the measurement object may be deformed by the force of pinching the measurement object between the measurement pieces,
The measurement value may differ depending on the operator.

[0004] If the two measuring pieces sandwiching and moving the object to be measured approach and move away from each other by the electric motor, the object to be measured can be clamped with a constant force. However, magnetism may leak from the electric motor to the outside. It cannot be used where magnetic leakage is undesirable.

An object of the present invention is to drive a movable measuring piece by a linear ultrasonic motor so that an object to be measured is clamped between the measuring pieces with a constant pressing force, thereby achieving low cost and high accuracy. An object of the present invention is to provide a measuring device capable of measuring a dimension.

[0006]

SUMMARY OF THE INVENTION A measuring apparatus according to the present invention comprises a support frame having a friction rail and a frame member which are parallel to each other and whose both ends are connected to each other by a connecting member, wherein both ends are fixed by the connecting member. A guide rail extending between the friction rail and the frame member, and a fixed-side measuring piece mounted at an end of the support frame so as to be reciprocally movable in the guide rail linear direction. A reciprocating member provided with a movable-side measuring piece sandwiching the object to be measured, an oscillator having a vibrating body in contact with the friction rail, and an ultrasonic oscillator mounted on the reciprocating member; The size of the object to be measured is measured by sandwiching the object to be measured between the side measurement piece and the movable side measurement piece.

In the present invention, when the object to be measured is sandwiched between the two measuring pieces to measure its dimensions, the movable measuring piece is driven by the ultrasonic oscillator. The dimension can be measured by applying a constant pressing force to the object, and the dimension can be measured with high accuracy.

In the measuring apparatus according to the present invention, a ferromagnetic magnetic scale is attached to the frame member, and a magnetic head for electromagnetically detecting a magnetic pattern of the magnetic scale is attached to the reciprocating member. Since the dimension between the measuring piece and the movable-side measuring piece is detected by the magnetic head, the dimension can be automatically measured with high accuracy by the magnetic scale. Since the movable measuring piece is driven by the ultrasonic vibrator, an external magnetic field affecting the magnetic scale and the magnetic head does not leak from the driving source, thereby preventing the malfunction of the magnetic head and achieving high precision. Can be used to measure the dimensions.

A fixed-side measuring piece is provided at each end of the support frame, and the movable-side measuring piece is reciprocated so that the object to be measured is efficiently moved between the fixed-side measuring piece and the movable-side measuring piece. Can be measured.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing a measuring apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged plan view partially omitted of FIG.

The measuring apparatus has a support frame 10, which has a friction rail 11 and a rod-shaped frame member 12 which are parallel to each other. The member 12 has a connecting member 13 at each end.
14 are connected.

A guide rail 15 extending parallel to the friction rail 11 and the frame member 12 is fixed between the two connection members 13 and 14. The guide rail 15 has a thickness smaller than the thickness of the support frame 10, and is fixed to the lower side in FIG. Mounting holes 16 are formed at predetermined intervals in the guide rails 15. By fitting a screw member into the mounting holes 16, the support frame 10 is attached to a fixing member (not shown) using the mounting holes 16. Can be fixed.

Two sliding blocks 17 and 18 are mounted on the guide rail 15 so as to be able to reciprocate in a linear direction along the guide rail 15 at a predetermined interval from each other.
7 and 18 are connected by a connecting rod 19, and the sliding blocks 17 and 18 and the connecting rod 19 form a reciprocating member 21. This reciprocating member 21 is shown in FIG.
As shown in the figure, the plane is generally U-shaped.

Guide grooves 22 are formed on the surfaces of the sliding blocks 17 and 18 alternately facing each other, and an ultrasonic vibrator 24 having a projection 23 meshing with the guide grooves 22 is moved by a reciprocating member 21. It is mounted so that it can be adjusted and moved in a direction perpendicular to the direction of movement of. The ultrasonic vibrator 24 is provided with a vibrating body 25, which comes into contact with the friction rail 11. In the ultrasonic vibrator 24, a piezoelectric ceramic as an electromagnetic strain element is fixed and incorporated on the surface of the elastic body, and the vibrating body 25 is vibrated by the electrostrictive action of the piezoelectric ceramic. The ultrasonic vibrator 24 can be moved along the guide rail 15 with respect to the friction rail 11 by the frictional force between the rail 11 and the vibrating body 25.

When a voltage is applied to the piezoelectric ceramic, the piezoelectric ceramic is deflected and longitudinally vibrates to generate a standing wave, which is transmitted to the vibrating body 25. By utilizing this standing wave, the ultrasonic transducer 24 moves in a linear direction along the friction rail 11.

A ball plunger 26 is attached to the connecting rod 19 of the reciprocating member 21 so that the vibrating body 25 comes into contact with the friction rail 11 with a predetermined frictional force. The ball plunger 26 is provided with a ball 27 for applying a pressing force in a protruding direction to the ultrasonic vibrator 24 by a spring member or the like incorporated therein. The ball plunger 26 moves the vibrator 25 against the friction rail 11. A preload applying member for pressing with a predetermined pressing force is configured.

A fixed measuring piece 31 is provided at one end of the support frame 10.
Is attached to one of the sliding blocks 17 of the reciprocating member 21, and a movable-side measuring piece 32 that sandwiches the workpiece W with the fixed measuring piece 31 is attached.

A thin plate-shaped magnescale or magnetic scale 33 made of a ferromagnetic material is attached to the frame member 12, and a sine-wave magnetic pattern having a constant period of about 200 μm is magnetized and recorded on the magnetic scale 33. Have been. To magnetically detect the magnetic pattern, two magnetic flux response type magnetic heads 34 and 35 are attached to the ultrasonic vibrator 24. Two magnetic heads 34, 3
Numeral 5 detects the sine wave of the magnetic pattern at a phase shifted from each other by 90 degrees, and can also detect the moving direction of the movable measurement piece 32.

FIG. 3 is a conceptual diagram showing the measuring principle of a measuring device having two magnetic heads 34, 35 and a magnetic scale 33. The signal from each magnetic head 34, 35 is processed to move the movable side. The distance between the measuring piece 32 and the fixed-side measuring piece 31 can be detected.

To supply high frequency power to the ultrasonic vibrator 24, one end of a flexible flat cable (not shown) is connected to the ultrasonic vibrator 24 as shown in FIG. This other end is a connecting member 13
Is connected to the connection plug provided in. A high-frequency power generation unit is connected to this connection plug.

FIG. 4 is a diagram showing a signal processing circuit of the measuring apparatus. Output signals from the magnetic heads 34 and 35 are sent to the control unit 41, respectively. The moving direction of the piece 32 and the distance between the moving direction of the piece 32 and the fixed-side measuring piece 31 can be detected. A control signal is sent from the control unit 41 to the high-frequency power generation unit 42.
Electric power of a predetermined frequency of 0 kHz or more is supplied to the piezoelectric ceramic of the ultrasonic vibrator 24, and the moving torque for moving the movable measurement piece 32 can be set to a predetermined value.

The measured dimension values are digitally displayed on a display unit 43, and an operation panel 44 is connected to the control unit 41 in order to input a command of the measuring device.

In order to measure the dimensions of the workpiece W using such a measuring device, the movable measuring piece 32 is sufficiently separated from the fixed measuring piece 31, and both the measuring pieces 31, An object to be measured W is arranged between 32. In this state, a signal is sent from the control unit 41 to the high-frequency power generation unit 42, and a pulse of a high-frequency current having a predetermined frequency is applied to the ultrasonic vibrator 24.

When the movable-side measuring piece 32 comes into contact with the workpiece W as the movable-side measuring piece 32 approaches the fixed-side measuring piece 31, the movement of the movable-side measuring piece 32 is regulated. A constant pressing torque is applied to the measured object W. When the movement of the movable measurement piece 32 is stopped, the movement is detected, and the dimension of the DUT W is calculated by the control unit 41 based on the measured values from the magnetic heads 34 and 35 at that time.
The value is displayed as a numerical value on the display unit 43.

In the measuring apparatus of the present invention, the movable measuring piece 32 is driven by the vibration of the vibrating body 25, so that the reciprocating member is driven by using the electric motor which is driven to rotate by the interaction between the current and the magnetic field. In such a case, a magnetic field is generated outside, but such a magnetic field is not generated outside, without causing magnetic disturbance to the magnetic heads 34, 35, and the malfunction of the magnetic heads 34, 35 is prevented. Can be prevented. Further, the measuring device of the present invention is effective for dimension measurement in a place where the influence of magnetic noise is not significant.

The present invention is not limited to the above embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention. For example, as shown by a two-dot chain line in FIG. 2, if the fixed-side measuring piece 31 a is also attached to the other end of the support frame 10, the movable-side measuring piece 32 is reciprocated alternately to fix the fixed side. The dimensions of the object to be measured can be measured between the side measurement piece 31 and the movable side measurement piece 32, and the dimensions of the object to be measured W can also be measured between the fixed side measurement piece 31a and the movable side measurement piece 32. can do. Accordingly, by arranging the workpieces W alternately on both end sides of the support frame 10, dimension measurement can be performed efficiently.

[0028]

As described above, according to the present invention, when measuring the dimensions of an object to be measured between the fixed-side measurement piece and the movable-side measurement piece, the movable-side measurement piece is linear. Because it is driven by the ultrasonic motor, the object to be measured can be sandwiched between both the measuring pieces by a constant torque, that is, a pressing force, and the dimension can be measured with high accuracy without measuring unevenness. . In addition, since no external magnetic field is generated from the member that drives the movable-side measuring piece, it is possible to measure the dimensions with high accuracy without erroneous operation of the magnetic head responsive to the magnetism of the magnescale. Dimensions of the object can be effectively measured in places where it is necessary to prevent influence on electromagnetic noise.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a measuring device according to an embodiment of the present invention.

FIG. 2 is a partially omitted enlarged plan view of FIG. 1;

FIG. 3 is a schematic view showing the principle of measurement using a magnescale.

FIG. 4 is a block diagram showing a signal processing circuit of the measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Support frame body 11 Friction rail 12 Frame member 13,14 Connecting member 15 Guide rail 16 Mounting hole 17,18 Sliding block 19 Connecting rod 21 Reciprocating member 22 Guide groove 23 Projection part 24 Ultrasonic transducer 25 Vibrating body 26 Ball Plunger 27 Ball 31 Fixed measurement piece 32 Movable measurement piece 33 Magnetic scale 34, 35 Magnetic head 41 Control unit 42 High frequency power generation unit 43 Display unit 44 Operation panel

Claims (2)

[Claims] 1. A support frame body having a friction rail and a frame member which are parallel to each other and both ends of which are connected to each other by a connection member, and both ends of which are fixed by the connection member, between the friction rail and the frame member. A movable-side measuring piece that is mounted so as to be reciprocally movable in the guide rail linear direction and that sandwiches the DUT between a fixed-side measuring piece provided at an end of the support frame. A reciprocating member provided with: a vibrating body that comes into contact with the friction rail; and an ultrasonic oscillator mounted on the reciprocating member, wherein the fixed-side measuring piece and the movable-side measuring piece A measuring apparatus characterized in that dimensions of the object to be measured are measured with the object to be measured interposed therebetween. 2. The measuring device according to claim 1, wherein a ferromagnetic magnetic scale is attached to the frame member, and a magnetic head for electromagnetically detecting a magnetic pattern of the magnetic scale is attached to the reciprocating member. A measuring device, wherein a dimension between a fixed-side measuring piece and the movable-side measuring piece is detected by the magnetic head.