JP2009058251A - Excitation tester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excitation tester which improves energy efficiency. <P>SOLUTION: The excitation tester is provided with a motor 2, an excitation shaft 1 which is provided penetrating the rotor of this motor and excites a test piece, and a converting means 4, 5 for converting the rotational motion of the rotor of the motor into linear motion of the excitation shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement of an excitation test apparatus.

Conventionally, the vibration test apparatus is provided with a hydraulic source for driving the test apparatus in addition to the test apparatus main body. Connected. Further, a high-speed responsive servo valve is connected to a hydraulic hose between the vibration test device and the drive source, and the cylinder moving speed and load are controlled by switching the servo valve (see Patent Document 1).
JP-A-53-23682

  However, in such a conventional vibration testing device, the drive source always generates a pressure and flow rate corresponding to the maximum load of the testing machine, so when the actually required pressure or flow rate is low. Increases the energy loss. As the loss increases, the amount of heat generation increases, the capacity of the cooling device for releasing heat increases, and the size increases.

  The present invention has been made in view of the above problems, and an object thereof is to provide an excitation test apparatus that improves energy efficiency.

  The present invention includes a motor, an excitation shaft that is provided through the rotor of the motor and that excites a test piece, and a conversion that converts the rotational motion of the rotor of the motor into linear motion of the excitation shaft. And a vibration testing apparatus.

  According to the present invention, energy efficiency can be improved by using a motor as a drive source of a vibration test apparatus. In addition, it is possible to improve the energy efficiency by using a motor as a drive source with a conversion stage for passing the excitation shaft through the rotor of the motor and converting the rotational motion of the rotor into the linear motion of the excitation shaft. . Further, by controlling the number of rotations of the motor, it is not necessary to control the stroke amount of the excitation shaft and provide a gear for shifting, etc., and the excitation test apparatus can be miniaturized.

  FIG. 1 is an assembly view of the vibration testing apparatus of the present invention, and FIG. 2 is an exploded view for explaining the components of the vibration testing apparatus.

  The vibration testing apparatus of the present invention includes a vibration unit 20 including a vibration shaft 1 connected to a test piece (not shown), and a direct drive motor (hereinafter simply referred to as a motor) that swings the vibration shaft 1 in the axial direction. ) 2, a cylindrical housing portion 40 in which the motor portion 30 is housed, and a housing portion 40 that supports the housing portion 40 so as to be swingable about an axis orthogonal to the axial direction. It is comprised from the bracket part 50 which fixes. Here, the direct drive motor is a motor that transmits the rotational force of the motor 2 directly to the drive target (excitation shaft 1) without using an indirect mechanism (gearbox or the like).

  The vibration unit 20 includes a vibration shaft 1, a load cell 6 that detects a load acting on the test piece from the vibration shaft 1, a displacement detection unit 8 that detects a stroke (displacement) amount of the vibration shaft 1, and a ball A ball screw nut 4 that strokes the vibration shaft 1 in the axial direction by using a screw mechanism and a spline nut 5 that restricts rotation of the vibration shaft 1 around the axis are provided. Here, the ball screw nut 4 and the spline nut 5 constitute conversion means for converting the rotational motion of the rotor of the motor 2 into the linear motion of the excitation shaft 1.

  The excitation shaft 1 is formed of a cylindrical member, and a screw groove that faces the ball screw nut 4 via the ball is formed on an outer peripheral surface thereof. Further, a concave spline groove is formed in the axial direction on the outer peripheral surface of the excitation shaft 1. A spline nut 5 having a convex portion that engages with the spline groove is disposed away from the ball screw nut 4 by a predetermined distance in the axial direction. The ball screw nut 4 is supported by a housing part 40 described later so as to be relatively rotatable, and the spline nut 5 is fixed to the housing part 40.

  With such a configuration, relative rotation between the excitation shaft 1 and the spline nut 5 is prohibited, and the movement of the housing portion 40 in the axial direction is prohibited by supporting the spline nut 5 to the housing portion 40. As the ball screw nut 4 rotates, the excitation shaft 1 strokes in the axial direction.

  A load cell 6 is installed at one end of the excitation shaft 1 on the side of the test piece, and a load acting on the test piece from the excitation shaft 1 is detected. An annular electromagnet 21 of the displacement detection means 8 is installed at the other end.

  The displacement detection means 8 includes an electromagnet 21, a magnetostrictive tube 22 provided with a coil wire, and a detection unit 23 provided at an end of the magnetostrictive tube 22. A pipe-shaped magnetostrictive tube 22 passes through the electromagnet 21 and is disposed in the hollow excitation shaft 1 so as to be relatively displaceable. The detection unit 23 detects the stroke amount of the excitation shaft 1.

  The axial stroke amount of the excitation shaft 1 is detected by using a magnetostrictive displacement detecting means 8 to apply a so-called Weedmann effect described in, for example, Japanese Patent Application Laid-Open No. 07-190015. This is because when a coil wire is provided in the magnetostrictive tube 22 and an electric current is passed through the provided coil wire, a circular magnetic flux is generated. This phenomenon is applied and is detected by the detection unit 23 by applying this phenomenon.

  A boot 24 is disposed on the outer periphery of the vibration shaft 1 between the load cell 6 and the ball screw nut 4 to prevent dust and the like from entering between the ball screw nut 4 and the screw groove of the vibration shaft 1.

  The ball screw nut 4 is fixed to an iron core 9 that constitutes the rotor of the motor 2, and the iron core 9 is formed in a cylindrical shape so that the excitation shaft 1 passes therethrough. A magnet 10 is fixed to the outer peripheral side of the iron core 9, and a stator 11 is disposed facing the outer peripheral surface of the magnet 10. The stator 11 is accommodated in the main body portion 12 of the housing portion 40. The rotation condition such as the rotation speed of the motor 2 is controlled by a controller (not shown), and the controller controls the motor 2 to control the stroke amount of the excitation shaft 1.

  The main body portion 12 constituting the housing portion 40 has a cylindrical shape, and a plurality of through holes penetrating the wall portion in the axial direction are formed on the same circumference at a predetermined interval. A U-shaped pipe 41 is provided to connect the open ends so that the through holes are connected in series. And the temperature of the motor 2 built in the housing part 40 is controlled to predetermined temperature by distribute | circulating the refrigerant | coolant which cools the motor 2 in this through-hole. The motor 2 or the housing part 40 in the vicinity of the motor 2 is provided with a sensor (not shown) that detects the temperature of the motor 2, and a controller (not shown) that supplies the refrigerant to the main body part 12 according to the detected temperature. Control the load state of

  A head flange 13 that closes the test piece side opening of the main body 12 is provided, and the ball screw nut 4 that supports the excitation shaft 1 is supported on the inner surface of the head flange 13 so as to be relatively rotatable. As the ball screw nut 4 rotates, the excitation shaft 1 expands and contracts in the axial direction from a through hole provided in the central portion of the head flange 13.

  Further, a bottom flange 14 that closes the other opening of the main body 12 is provided. The aforementioned spline nut 5 is fixed to the inner end surface of the bottom flange 14. Further, a cylindrical magnetostrictive tube housing 15 that houses the displacement detection means 8 is fixed to the outer end surface of the bottom flange 14, and a magnetostrictive tube fixing flange 16 that closes the opening and fixes the detection portion 23 of the displacement detection means 8. Installed.

  A pair of support shafts 17 projecting in a direction orthogonal to the axial direction of the excitation shaft 1 are provided on the outer peripheral surface of the main body portion 12 of the housing portion 40, and the support shafts 17 are swingably supported by the bracket portion 50. In addition, the excitation direction is set at a predetermined angle.

  Next, the operation will be described.

  In the vibration testing apparatus of the present invention, a vibration shaft 1 that vibrates a test piece is configured as a constituent member of a ball screw mechanism, and a ball screw nut 4 that strokes the vibration shaft 1 in the axial direction by the ball screw mechanism is used as a motor. The ball screw nut 4 is directly rotated by the motor 2 by being fixed to the rotor 2. For this reason, by controlling the driving conditions of the motor 2, the test piece is vibrated with a predetermined stroke amount, load, frequency, and the like. Thus, energy efficiency can be improved compared with the case where a hydraulic cylinder is used as a drive source by comprising a vibration test apparatus by using the motor 2 as a drive source. In addition, since the excitation shaft is provided through the rotor of the motor, conversion means configured using a ball screw mechanism that converts the rotational motion of the rotor of the motor 2 into the linear motion of the excitation shaft 1 is provided. The vibration testing apparatus can be downsized.

  The excitation shaft 1 that is axially displaced with respect to the housing portion 40 is formed in a hollow shaft shape, and a displacement detection means 8 that detects the stroke amount of the excitation shaft 1 is installed in the hollow portion. As the displacement detection means 8, for example, a displacement detection means using a magnetostrictive tube 22 and an electromagnet 21 based on the Weedmann effect is arranged. With such a configuration, the stroke amount of the excitation shaft 1 can be detected accurately, space saving can be achieved, and the weight can be reduced by making the excitation shaft 1 hollow.

  A flow path (through hole) for circulating the refrigerant is formed in the wall portion of the housing portion 40 that houses the motor 2, and the temperature of the motor 2 can be maintained at a predetermined temperature.

  FIG. 3 is an exploded view of the vibration testing apparatus of the second embodiment. In the configuration of this embodiment, the configurations of the cylindrical excitation shaft 1 and the housing portion 40 that are the configuration of the excitation unit 20 are changed from those of the first embodiment.

  Specifically, the spline groove and the spline nut 5 formed on the vibration shaft 1 are eliminated, and the vibration shaft 1 has a screw groove whose length is set in consideration of the stroke amount of the vibration shaft 1. The formed screw portion 25 and a rod-shaped sliding portion 26 having a polygonal cross-section, for example, a square cross-section as viewed from the axial direction, are arranged in parallel in the axial direction.

  The sliding portion 26 is similar to the cross-sectional shape of the sliding portion 26 formed in the housing portion 40, that is, is slidably supported in the axial direction through a rectangular hole (not shown). At the same time, rotation around the axis of the excitation shaft 1 is prohibited.

  By adopting such a configuration, while maintaining the effects of the first embodiment, the spline groove and the spline nut 5 can be eliminated to reduce the cost and improve the strength.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The present invention can be applied to a vibration test apparatus that vibrates a test piece.

It is an assembly drawing of the vibration test apparatus to which the present invention is applied. It is an exploded view of a vibration test apparatus. It is an exploded view of the vibration test apparatus of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excitation shaft 2 Motor 4 Ball screw nut 5 Spline nut 6 Load cell 8 Displacement detection means 9 Iron core 10 Magnet 11 Stator 12 Body part 13 Head flange 14 Bottom flange 15 Magnetostrictive tube housing 16 Magnetostrictive tube fixing flange 17 Support shaft 20 Excitation part 21 Electromagnet 22 Magnetostrictive tube 23 Detecting section 24 Boot 25 Screw section 26 Sliding section 30 Motor section 40 Housing section 41 Pipe 50 Bracket section

Claims (8)

A motor,
An excitation shaft provided through the rotor of the motor, for exciting the test piece,
An excitation test apparatus comprising: conversion means for converting rotational motion of the rotor of the motor into linear motion of the excitation shaft.   The excitation test apparatus according to claim 1, wherein the excitation shaft is formed in a hollow shape, and a displacement detection unit that detects a displacement amount of the excitation shaft with respect to the housing portion is provided in the hollow portion. . The displacement detection means includes a magnet installed on the excitation shaft, and a magnetostrictive tube installed in a hollow portion of the excitation shaft so as to be relatively displaceable and provided with a coil wire.
When a current is passed through the coil wire, an orbiting magnetic flux is generated, and when a magnetic field is applied from the magnet in a direction perpendicular to the orbiting magnetic flux, the magnetostrictive tube is twisted to detect the displacement amount of the excitation shaft. 3. The vibration testing apparatus according to claim 2, wherein A housing portion that houses the motor,
The vibration test apparatus according to claim 3, wherein the housing has a cylindrical shape, and a coolant for cooling the motor flows through a wall portion of the housing.   The said housing is equipped with the pipe material which connects the through-hole which penetrates the said wall part to an axial direction, and the opening part of each adjacent through-hole, and connects the said through-hole in series. Vibration test equipment. The converting means includes
A screw groove formed on the outer peripheral surface of the excitation shaft;
An axial groove formed in the axial direction of the outer peripheral surface of the excitation shaft;
A ball screw nut connected to the screw groove via a ball and rotating together with a rotor of the motor, while being rotatably supported by the housing portion;
The excitation test apparatus according to claim 4, further comprising a spline nut that engages with the axial groove and prohibits rotation of the excitation shaft. The excitation shaft is composed of a screw groove portion having a screw groove formed on an outer peripheral surface, and a slide portion supported so as to be slidable in the axial direction with respect to the housing portion and non-rotatable.
The converting means includes
A screw groove and a sliding portion of the excitation shaft;
5. The additive according to claim 4, further comprising: a ball screw nut connected to the screw groove via a ball and rotating together with a rotor of the motor while being rotatably supported by the housing portion. Vibration test equipment. The sliding portion is formed in a rod shape having a polygonal cross section when viewed from the axial direction,
The vibration test apparatus according to claim 7, wherein the housing portion includes a hole portion similar to a cross-sectional shape of the sliding portion.