JP2005073419A - Adjusting method for installation of magnet shaft in linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adjusting method for installation of a magnet shaft in a linear motor wherein when a moving member coil is disposed in a predetermined position in the linear motor, the magnet shaft is moved and positioned with accuracy so that the magnetic poles of the moving member coil and those of the magnet shaft are accurately aligned with each other, and this positioning is carried out with ease. <P>SOLUTION: The adjusting method is for the installation of the magnet shaft 3 in the linear motor 1 provided with the moving member coil 2 and the magnet shaft 3. The moving member coil 2 is fixed in a predetermined reference position, and thereafter a current in predetermined phase is supplied to the moving member coil 2 to move the magnet shaft 3. When the magnet shaft 3 is stopped, it is fixed there. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for adjusting the mounting of a magnet shaft in a linear motor, and more particularly to a method for adjusting the mounting of a magnet shaft in a linear motor in which a mover coil is fixed and current is supplied and the magnet shaft is moved and positioned easily and accurately. .

  Rotary motors are often used to drive industrial products, industrial machines, etc. (hereinafter referred to as “devices”), but in recent years linear motors are also expanding their applications, and many industrial products using linear motors have been developed. Has been. In order to properly operate such a device, it is necessary to accurately control the operation of the motor. For this purpose, first, it is necessary to accurately align the magnetic poles of the motor before starting the operation of the motor. Here, the alignment of the magnetic poles is to match the current phase of the mover coil and the phase of the magnetic flux density distribution of the magnet shaft so that the torque of the motor is maximized.

In other words, the position of the rotor and mover coil relative to the stator and magnet shaft is detected in advance, and the rotor and mover coil are moved accurately from that position and with the maximum motor torque at the start of operation. The optimum value of the phase of the current to be supplied in order to obtain it is determined. As a method for detecting the position of the rotor or mover coil, for example, the magnetic pole position of the rotor is determined from the phase difference between the rotational angle applied to the motor by minutely vibrating the rotor in the rotational direction with respect to the stator. A detection method has been proposed (see Patent Document 1). A method of detecting the magnetic pole position by directly measuring the magnetic pole of the rotor using a magnetic pole sensor has also been proposed (see Patent Document 2). Simultaneously with such position detection, an optimum value such as the phase of the current to be supplied to the motor is obtained.
JP-A-5-3695 JP 2002-176749 A

  However, in these methods, it is necessary to detect and measure the magnetic poles and to determine the optimal current phase when the motor is initialized after the power is turned on. It is troublesome to perform such work for each initialization. In addition, a detection / measurement means such as a magnetic pole sensor must be attached to the motor, which increases the cost. Such a point is not limited to the case of the rotary motor as described above, but also becomes a problem in the case of a linear motor.

  On the other hand, the linear motor is generally provided with means for detecting the position of an encoder or the like, and can easily recognize the position of the mover coil with respect to the magnet shaft. Therefore, if the mover coil is accurately arranged at a predetermined position on the magnet shaft and an optimum value such as the phase of a current (for example, three-phase alternating current described later) to be supplied to the mover coil at this position is found, Thereafter, there is no need to detect the optimum value such as the phase of the current again, and there is an advantage that the linear motor can be accurately operated only by arranging the mover coil at this position and supplying the optimum value of current. .

  That is, only by arranging the mover coil at a predetermined position of the magnet shaft, the position detection and the calculation of the optimum value of the current are already completed. However, in a mass-produced apparatus such as an image reading apparatus or an image recording apparatus, variation occurs between apparatuses due to mechanical tolerances. Therefore, in order to accurately control the operation of a linear motor, at least once The optimum value of the phase must be determined and the optimum value of the correct phase must be given. Considering mass production of equipment, if such precise work is carried out for each equipment, the work becomes complicated and takes time, leading to a problem of reduced production efficiency.

  In order to avoid the complexity of performing the above-mentioned operations for each product, the linear motor magnet shaft may be physically positioned, for example, by being brought into contact with the inside of the apparatus. That is, by using a model linear motor, for example, the magnet shaft is brought into contact with or fitted to a predetermined position in the apparatus to determine the fixed position of the magnet shaft to the apparatus, and the mover coil is magnetized. The optimal current value when the shaft and the device are arranged at the predetermined position is determined, and in the manufacture of the device, the above-described indexing work is not performed and the magnet shaft is fixed at the same fixed position in the model and the device. To manufacture. If the mover coil is arranged at a predetermined position of the device manufactured in this way, the optimum value of the current to be passed through it is already determined.

  However, in reality, the position of the magnet shaft relative to the device and the mechanical tolerance of the mover coil when the mover coil is placed at a predetermined position make the position delicate with respect to the position of the optimum value of the phase. Therefore, for example, even if the mover coil is arranged at a predetermined position, there arises a problem that it is necessary to supply a current larger than the current to be supplied when the motor is operated, or the conveyance speed fluctuates. In some cases, the operation control of the motor is not always accurately performed.

  Accordingly, the present invention provides a magnet shaft in which a phase of a current of a mover coil and a phase of a magnetic flux density of a magnet shaft are accurately aligned in a linear motor when the mover coil is arranged at a predetermined position. It is an object of the present invention to provide a method for adjusting the mounting of a magnet shaft in a linear motor, which makes it possible to accurately position and to easily perform such positioning. And it aims at providing the attachment adjustment method of the magnet shaft in a linear motor which makes it possible to control a linear motor correctly by it.

  In order to solve the above problems, a magnet shaft mounting adjustment method in a linear motor according to the present invention is a magnet shaft mounting adjustment method in a linear motor including a mover coil and a magnet shaft. The magnet shaft is moved by supplying a current having a predetermined phase to the mover coil after being fixed at a position, and the magnet shaft is fixed at a position where the magnet shaft is stopped.

  According to the first aspect of the present invention, since the magnet shaft is moved and fixed by supplying a current having a predetermined phase to the mover coil fixed at the predetermined reference position, the movable element disposed at the reference position is fixed. The optimum value of the phase of the current to be supplied to the child coil is obtained.

  According to a second aspect of the present invention, in the method for adjusting the mounting of the magnet shaft in the linear motor according to the first aspect, after supplying the current of a predetermined phase to the mover coil and moving the magnet shaft. Furthermore, the magnet shaft is moved by rotating the phase of the current.

  According to the second aspect of the present invention, in the method for adjusting the attachment of the magnet shaft in the linear motor according to the first aspect, the position slightly varies due to the influence of the static friction torque and the dynamic friction torque when the magnet shaft is moved. Can be prevented.

  According to a third aspect of the present invention, in the method for adjusting the attachment of the magnet shaft in the linear motor according to the first or second aspect, the magnet shaft is moved while being supported by a guide.

  According to the invention described in claim 3, by arranging the position of the guide so that the magnet shaft passes through the center of the mover coil, the magnet shaft rubs against the mover coil, or between the magnet shaft and the mover coil. The magnet shaft can be prevented from being distorted, and the frictional resistance can be reduced to move the magnet shaft smoothly.

  According to a fourth aspect of the present invention, in the method for adjusting the attachment of the magnet shaft in the linear motor according to any one of the first to third aspects, the linear motor is arranged in the vertical direction and positioned. And

  According to the fourth aspect of the present invention, the magnet shaft can be positioned even when the linear motor is arranged in the vertical direction.

  According to a fifth aspect of the present invention, in the method for adjusting the attachment of the magnet shaft in the linear motor according to the fourth aspect, the positioning is performed by moving the magnet shaft upward during the positioning.

  According to the fifth aspect of the present invention, it is possible to avoid a phenomenon such as a backlash that does not move even when the mover coil supplies a current having an optimum phase due to the friction torque between the magnet shaft and the fixed member. it can.

  According to a sixth aspect of the present invention, in the magnet shaft mounting adjustment method for the linear motor according to any one of the first to fifth aspects, the magnet of the image reading apparatus or the image recording apparatus conveyed by the linear motor. The shaft is positioned.

  According to the invention described in claim 6, in an image reading apparatus that reads a radiation image serving as a diagnostic material and converts it into an electric signal, or an image recording apparatus having basically the same structure as the image reading apparatus, It is possible to accurately position the magnet shaft of the linear motor serving as the reference for

  According to the first aspect of the present invention, the magnet shaft can be accurately positioned with respect to the apparatus by a simple operation of fixing the mover coil at the reference position and supplying a predetermined current to the mover coil. Therefore, it becomes possible to accurately control the linear motor and the apparatus using the linear motor.

  According to the second aspect of the present invention, it is possible to prevent the occurrence of a phenomenon such as backlash due to the friction torque during the movement of the magnet shaft, and the magnet shaft can be positioned more accurately and accurately. Become.

  According to the invention described in claim 3, by adjusting the position of the guide so that the magnet shaft passes through the center of the mover coil, the magnet shaft is rubbed against the mover coil or between the magnet shaft and the mover coil. Therefore, the magnetic shaft can be positioned more accurately.

  According to the fourth aspect of the invention, since the magnet shaft can be positioned even when the linear motor is arranged in the vertical direction, the linear motor can be accurately operated even in such a case. . In addition, by arranging in the vertical direction, it can be moved smoothly even without a guide, and further, positioning accuracy is improved because gravity and torque due to current applied to the mover coil are balanced. Can be made.

  According to the fifth aspect of the present invention, it is possible to avoid a phenomenon such as a backlash that does not move even when the mover coil supplies a current having an optimum phase due to the friction torque between the magnet shaft and the fixed member. Therefore, the magnet shaft can be positioned more accurately.

  According to the invention described in claim 6, in an image reading apparatus that reads a radiation image serving as a diagnostic material and converts it into an electric signal, or an image recording apparatus having basically the same structure as the image reading apparatus, Therefore, the linear motor can be operated with higher accuracy, and the image reading device and the image recording device can be operated with higher accuracy.

  Hereinafter, an embodiment of a magnet shaft mounting adjustment method in a linear motor of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram for explaining a linear motor and other members used for carrying out the method of the present invention. A member 6 (hereinafter referred to as a reference member 6) serving as a reference for fixing the position of the mover coil 2 is fixed to an apparatus (not shown) for attaching the linear motor 1. In that case, the reference member 6 may be a part of the apparatus, or may be a separate member fixed to the apparatus. In this reference member 6, the mover coil 2 having a cylindrical through hole formed in the center is held via a holding means 7 and fixed at a predetermined reference position. The holding means 7 is appropriately selected according to the structure, size, material, and the like of the mover coil 2, and prevents the mover coil 2 from moving by various methods such as adhesion, adsorption, clamping, fitting, and screw fixing. Hold. The mover coil 2 is formed so that a predetermined current is supplied from the current supply means 5 via the cable 4.

  Further, a cylindrical or rod-shaped magnet shaft 3 is inserted into the through hole of the mover coil 2 at a certain distance from the inner wall of the through hole. Fixing members 8 and 8 for fixing the magnet shaft 3 are provided in the apparatus at both ends in the longitudinal direction of the magnet shaft 3, and the magnet shaft 3 is finally positioned after being positioned by the mounting adjustment method of the present invention. Thus, the fixing members 8 and 8 are fixed. However, until the position is finally determined as will be described later, the magnet shaft 3 moves in the longitudinal direction (left and right in FIG. 1), so that the outer ends 8a and 8a of the fixing members 8 and 8 are opened. It is preferable if it is formed in the state.

  Next, a method for adjusting the attachment of the magnet shaft in the linear motor of the present invention will be described.

  As described above, when a current having a predetermined phase (hereinafter referred to as an initial current) is supplied to the mover coil after the mover coil 2 is fixed at a predetermined reference position, the mover coil 2 is fixed in reverse to the normal linear motor. The magnet shaft 3 moves slightly in any one of the longitudinal directions of the mover coil 2 (right or left in FIG. 1) and stops. The magnet shaft 3 is fixed to the fixing members 8, 8 at the stopped position, and the positioning of the magnet shaft 3 with respect to the apparatus is completed. The reference member 6 and the holding means 7 are appropriately removed from the mover coil 2 after this positioning operation.

  Specifically, it is assumed that, for example, a three-phase alternating current of phase A shown in FIG. 2 is supplied as an initial current from the current supply means 5 to the mover coil 2 fixed at a predetermined reference position. Then, a force (torque) is generated between the mover coil 2 and the magnet shaft 3 by the magnetic flux of the magnet shaft 3 and the current of each phase of the three-phase alternating current of phase A. Therefore, the magnet shaft 3 moves to a position where all the forces (torque) applied to the magnet shaft 3 are canceled and stops. The magnet shaft 3 is fixed at the stop position. Here, as the phase A, for example, by supplying a current of a phase in which the U phase becomes 0 (in this case, the V phase and the W phase have the same absolute value and opposite currents). It is also possible to employ a simplified current supply method in which current is supplied to only two phases of the W phase.

  On the contrary, the mover coil 2 in a movable state in which the magnet shaft 3 is fixed at the stopped position and the holding means 7 is removed is disposed at the same predetermined reference position as described above, and the phase shown in FIG. Even if the three-phase alternating current of A is supplied, the force received by the mover coil 2 from the magnet shaft 3 as a reaction force of the magnetic force is canceled out. Therefore, the mover coil 2 is naturally a magnet shaft fixed to the apparatus. 3 does not start moving in the longitudinal direction, and remains stationary at the reference position.

  That is, when the magnet shaft 3 is positioned in this way, the predetermined reference position becomes the starting point of the operation of the mover coil 2 and the optimum value of the phase of the current to be supplied is accurately determined. Can be formed. In this way, a reference for accurate operation control of the motor is provided. Then, by rotating (that is, changing) the phase of the current to be supplied, the mover coil 2 can be freely moved in the longitudinal direction of the magnet shaft 3 according to the rotation, and the moving speed can be increased by changing the frequency. It can also be changed. That is, the operation control of the linear motor 1 and the apparatus using the same can be performed accurately.

  As described above, according to the method for adjusting the mounting of the magnet shaft in the linear motor of the present invention, it is possible to fix the mover coil 2 at the reference position and supply a predetermined current to the mover coil 2 with a simple operation. The magnet shaft 3 can be accurately positioned. At the same time, the optimum value of the phase of the current to be supplied to the mover coil 2 at the reference position is obtained. Therefore, it is possible to easily and accurately control the linear motor 1 and the apparatus using the linear motor 1.

  When the magnet shaft 3 is actually positioned by the method of the present invention, the magnet shaft 3 stops moving while the position of the magnet shaft 3 slightly varies due to the friction torque when the magnet shaft 3 moves. It may be fixed as it is. In such a case, there is a variation (machine difference) between devices in the current phase of the mover coil 2 and the magnetic flux phase of the magnet shaft 3, and the accuracy of the operation control is lowered.

  In order to prevent such a situation, as shown in FIG. 3, a current of a predetermined phase A is supplied to the fixed mover coil 2 to move the magnet shaft 3, and then the phase of the current is changed from the phase A. The magnet shaft 3 is preferably moved by rotating to the phase B. In this way, by further rotating the phase of the current and moving the magnet shaft 3, the friction torque can be converged in one direction, the variation in position can be reduced, and the control of the linear motor 1 is more accurate. It is possible to perform well.

  Further, as shown in FIG. 1, when positioning the magnet shaft 3 so that the longitudinal direction thereof is in the horizontal direction, the magnet shaft 3 naturally receives gravity downward. Therefore, in the present embodiment, the magnet shaft 3 is biased downward in the through hole of the mover coil 2, or the lower end portion of the magnet shaft 3 is rubbed against the inner wall of the through hole of the mover coil 2. May not move.

  In such a case, as shown in FIG. 4A, guides 9 and 9 that support the magnet shaft 3 from below are provided, and the magnet shaft 3 may be moved while being supported by the guides 9 and 9. In this case, when the linear motor 1 is viewed from the side as shown in FIG. 4B, the above situation can be avoided by arranging the guide 9 so that the magnet shaft 3 passes through the center of the mover coil 2. In addition, the above-described distortion of the magnetic flux (magnetic force) between the magnet shaft 3 and the mover coil 2 can be eliminated, and the friction torque can be reduced. For this reason, the magnet shaft 3 can be positioned more accurately.

  On the other hand, as shown in FIG. 1 etc., the case where the magnet shaft 3 was moved and positioned so far was described. However, it is also possible to position the magnet shaft 3 by moving it in the vertical direction.

  That is, as shown in FIG. 5, it is also possible to position the magnet shaft 3 by arranging the linear motor 1 in the vertical direction and using the mounting adjustment method of the present invention. Even when the linear motor 1 is arranged in the vertical direction, the procedure of the mounting adjustment method of the present invention is the same as that in the horizontal direction described above, and the description of the arrangement in the horizontal direction also applies to the case where it is arranged in the vertical direction as it is. Applicable. Also in this case, naturally, since the magnet shaft 3 can be positioned with high accuracy, the linear motor 1 can be operated with high accuracy.

  In addition, there is a case where the magnet shaft 3 stops moving and is fixed as it is due to the frictional torque generated when the magnet shaft 3 moves. In such a case, the current phase of the mover coil 2 and the phase of the magnetic flux density of the magnet shaft 3 cause a variation (machine difference) between devices, and the accuracy of operation control is reduced. Therefore, even in vertical conveyance, positioning can be performed with higher accuracy by rotating the current phase of the mover coil 2 and moving the magnet shaft 3 upward or downward for positioning.

  Furthermore, since force is always applied to the magnet shaft 3 downward due to the gravitational acceleration, it is difficult to absorb position variations due to the influence of friction torque if the magnet shaft 3 is moved downward. Therefore, it is preferable to position the magnet shaft 3 by moving it upward. By moving upward, the influence of friction torque can be absorbed and the positioning accuracy can be further improved.

  Here, embodiments of an image reading apparatus and an image recording apparatus to which the mounting adjustment method in the linear motor of the present invention is applied will be described. The image reading device accumulates the energy of the radiation transmitted through the subject for diagnosis by radiographic images typified by X-ray images, and irradiates the recorded photostimulable phosphor with excitation light to generate fluorescence. Then, it is read and converted into an electrical signal to create a radiation image. The image recording apparatus is configured to record the image on the recording medium by irradiating the recording medium with laser light instead of such image reading, and the basic structure is the same as that of the image reading apparatus. Therefore, the following description of the image reading apparatus also applies to the image recording apparatus.

  FIG. 7 is a schematic perspective view showing a main part of an embodiment of an image reading apparatus to which the attachment adjusting method of the present invention is applied. A plate-like support member 10 is erected in a vertical direction on a base (not shown) below the image reading apparatus A. On the front side and the rear side of the support member 10, a belt-like connecting member 12 is suspended via a plurality of pulleys 11 a, 11 b, 11 c provided on the upper part, and the front side of the supporting member 10 of the connecting member 12. A plate-like pedestal 13 is connected to the end, and a counterweight (not shown) that balances the pedestal 13 and the like is connected to the end on the rear side.

  A back plate 15 that holds the photostimulable phosphor sheet 14 is attached to the front surface of the base portion 13. On the front side of the photostimulable phosphor sheet 14, a reading unit 16 that reads the radiation energy recorded on the photostimulable phosphor sheet 14 by irradiating the photostimulable phosphor sheet 14 with excitation light is provided. The image reader A is provided in the main body of the image reading apparatus A in a state facing the photostimulable phosphor sheet 14 at a position slightly separated from the phosphor sheet 14.

  An attachment member 17 is fixed to the rear surface of the base portion 13. A member to be guided (not shown) is attached to the attachment member 17 and is guided by a rod-shaped guide rail 18 provided in the vertical direction substantially at the center of the front surface of the support member 10. Therefore, the base 13 and the photostimulable phosphor sheet 14 are guided in the vertical direction by the guide rail 18 through the guided member and the mounting member 17.

  A mover coil 19 having a cylindrical through hole formed in the center is fixed to the side surface of the mounting member 17, and a magnet shaft 20 is inserted into the through hole of the mover coil 19. Support pieces 22 and 22 provided with cylindrical fixing members 21 and 21 for fixing the upper end and lower end of the magnet shaft 20 are provided integrally with the support member 10 at the upper and lower portions of the support member 10, respectively. ing. On the front surface of the support member 10, a linear scale 23 constituting an encoder for detecting the position and moving speed of the base portion 13 is provided in parallel to the guide rail 18 in the vertical direction. A sensor unit (not shown) that constitutes an encoder and reads the linear scale 23 is fixed at a position facing the linear scale 23 on the rear surface of the base unit 13.

  In the image reading apparatus A configured as described above, in order to position the magnet shaft 20 of the linear motor, first, the screw of the fixing member 21 that fixes the magnet shaft 20 is removed, and the magnet shaft 20 is moved up and down. Make it movable in the direction. Then, the base part 13 is moved to a predetermined operation start position in a state where the sensor part of the encoder is operated, and the base part 13 is fixed to the main body of the image reading apparatus A and the support member 10 at that position using a predetermined holding means. To do. In this state, by supplying a current having a predetermined phase to the mover coil 19, the magnet shaft 20 is moved and fixed by the fixing member 21.

  By positioning the magnet shaft 20 as described above, all the effects of the present invention described above are exhibited. In particular, since the image reading apparatus A reads a radiographic image as a diagnostic material and converts it into an electrical signal, the apparatus is required to operate properly. As described above, for example, the magnet shaft 20 The linear motor can be operated with higher accuracy by moving the motor upward and positioning it to improve the positioning accuracy. Therefore, it is possible to operate the image reading apparatus A with high accuracy.

It is a schematic diagram explaining the linear motor other member used for this embodiment. It is a graph of the phase and current intensity of a three-phase alternating current supplied to a mover coil. It is a graph of the three-phase alternating current explaining the state which rotates the phase of the electric current supplied to a needle | mover coil. (A) is a schematic diagram explaining the guide which supports a magnet shaft from the lower side, (B) is the schematic diagram which looked at the linear motor of (A) from the side. It is a schematic diagram explaining the state which arrange | positions a linear motor to a perpendicular direction, and positions a magnet shaft. It is a schematic diagram explaining the actual operation state at the time of arrange | positioning a linear motor to a perpendicular direction. It is a schematic perspective view which shows the principal part of embodiment of the image reading apparatus with which the attachment adjustment method of this invention is applied.

Explanation of symbols

1 linear motor 2 mover coil 3 magnet shaft 9 guide 19 mover coil 20 magnet shaft A image reading device

Claims (6)

In a method for adjusting the mounting of a magnet shaft in a linear motor having a mover coil and a magnet shaft,
After the mover coil is fixed at a predetermined reference position, the magnet shaft is moved by supplying a current of a predetermined phase to the mover coil, and the magnet shaft is fixed at a stopped position. To adjust the mounting of the magnet shaft in the linear motor.   2. The method according to claim 1, wherein after the magnet shaft is moved by supplying a current having a predetermined phase to the mover coil, the magnet shaft is further moved by rotating the phase of the current. 3. A method for adjusting the mounting of a magnet shaft in a linear motor.   The method for adjusting the attachment of a magnet shaft in a linear motor according to claim 1 or 2, wherein the magnet shaft is moved while being supported by a guide.   The method for adjusting the attachment of a magnet shaft in a linear motor according to any one of claims 1 to 3, wherein the linear motor is positioned and positioned in a vertical direction.   5. The method for adjusting the mounting of a magnet shaft in a linear motor according to claim 4, wherein the positioning is performed by moving the magnet shaft upward during the positioning.   6. The method for adjusting the mounting of a magnet shaft in a linear motor according to any one of claims 1 to 5, characterized in that the positioning is performed on a magnet shaft of an image reading device or an image recording device conveyed by the linear motor.

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