JP2014185939A - Shutter of radiation thickness measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and simple shutter of a radiation thickness measuring device which reduces impact at a position stopping rotations of a rotary solenoid, suppresses bounding of the shutter, and extends a life.SOLUTION: A shutter driving portion 5 includes: a rotary solenoid provided so as to have an axial direction of a rotation shaft 5a1 of the rotary solenoid 5a in a vertical direction; and a shutter holder plate 5b fixed to a rotation shaft in a horizontal state orthogonal to an axial direction of the rotation shaft, and fixed with a lead plate 5c ot a thickness reference sample plate at one end. A shutter control portion pulse-duration modulates an excitation power source to the rotary solenoid during a fixed time period from a predetermined speed-reduction start position to a rotation finish position, and suppresses impact to a fixing portion of the lead plate or the thickness reference sample plate fixed to the shutter holder plate and the rotation shaft, at a position where the rotations of the rotary solenoid stops.

Description

  Embodiments described herein relate generally to a shutter of a radiation thickness measurement apparatus.

Conventionally, a thickness measuring apparatus using an X-ray or a radioisotope has been used for measuring a thickness of a steel sheet, such as a rolling process. The configuration of such a radiation thickness measuring apparatus is shown in FIG.

The radiation thickness measuring apparatus 100 includes a radiation generating unit 3 that irradiates the object to be measured 20 such as a steel plate, a radiation detector 4 that detects radiation transmitted through the object to be measured 20, and the radiation generating unit 3. The shutter 10 includes a shutter driving unit 50 that opens and closes the irradiated radiation and a shutter control unit 60 that controls opening and closing of the shutter driving unit 50.

In addition to the lead plate that shields radiation, the shutter 10 may include a plurality of thickness reference sample plates that serve as a reference for thickness. Here, a shutter including a lead plate and a plurality of thickness reference sample plates is also referred to as a shutter.

For such a radiation thickness measuring apparatus 100, a technique for preventing malfunction of an opening / closing operation abnormality detection circuit at the time of shutter opening / closing using a solenoid is disclosed (for example, see Patent Document 1).

In addition, a technique is disclosed in which an X-ray thickness meter includes a plurality of thickness reference sample plates and a thickness calibration curve is set and changed in a short time (see, for example, Patent Document 2). In Patent Document 2, the shutter 10 referred to here is referred to as a standard magazine.

The shutter 10 used for shielding the radiation and changing the setting of the thickness calibration simultaneously with the shielding of the radiation is required to have a long life because it is used at high speed and frequently.

Further, since the radiation thickness measuring apparatus 100 is limited in the installation space, it is also required that the radiation thickness measuring apparatus 100 has a compact size that can be inserted into this space. In particular, since the dimension in the flowing direction of the object to be measured 20 and the height dimension H from the floor (FL) to the object to be measured 20 are restricted, the radiation generator 3 and the shutter drive unit 50 provided on the radiation generating part 3 are arranged. The vertical dimension is required to be a compact structure.

Japanese Patent Publication No. 6-76885 Japanese Patent Publication No. 2-37523

In order to drive the shutter driving unit 50 of the shutter 10 of the radiation thickness measuring apparatus 100 as described above, a rotary solenoid that is compact and capable of opening and closing at high speed has been used.

In the shutter structure (not shown), a sample holder plate is fixed to the rotating shaft of the rotary solenoid, and a lead plate or a thickness reference sample plate is fixed to one end of the horizontal surface of the sample holder plate.

Then, by energizing the solenoid, the center axis of the radiation passage and the lead plate or the center of the thickness reference sample plate are aligned at the position where the sample holder plate is rotated and stopped in one direction. It is set in advance so as to be in a position out of the radiation path when rotated in the reverse direction.

However, when the rotary solenoid is rotated, at the position where the rotation is stopped, an impact is applied to the rotary shaft of the rotary solenoid due to the moment of inertia due to the load of the sample holder plate and the lead plate fixed to the sample plate or the thickness reference sample plate. The lead plate and thickness standard sample plate could be broken. There is also a problem that the life of the rotary shaft of the rotary solenoid is shortened.

Further, when trying to rotate the rotary solenoid at a high speed, there is a problem that at the position where the rotation is stopped, the sample holder plate bounces and it takes a long time to stop.

The present invention has been made to solve the above-described problems. In the shutter of the radiation thickness measuring apparatus, the impact at the position where the rotation of the rotary solenoid is stopped is reduced, the shutter bounce is less, and the life is extended. An object of the present invention is to provide a shutter for a compact and simple radiation thickness measuring apparatus.

In order to achieve the above object, the shutter of the radiation thickness measurement apparatus of the present embodiment is a shutter of the radiation thickness measurement apparatus, and the shutter includes a lead plate or a thickness reference sample plate,
Rotate the rotary solenoid in one direction to move it to a position that closes the radiation path,
A shutter drive unit that reverses in the other direction and moves to a position outside the radiation path; and a shutter control unit that controls a rotation operation of the shutter drive unit, wherein the shutter drive unit rotates the rotary solenoid. The rotary solenoid provided with the axis direction of the shaft in the vertical direction, and fixed to the rotary shaft in a horizontal state perpendicular to the axial direction of the rotary shaft, and the lead plate or the thickness reference sample plate is fixed to one end A position at which rotation of the rotary solenoid stops by pulse width modulating the excitation power to the rotary solenoid for a certain period of time from a predetermined deceleration start position to a rotation end position. In the lead plate fixed to the shutter holder plate or the fixing portion of the thickness reference sample plate, and the rotating shaft Characterized in that so as to reduce the impact of.

The block diagram of the shutter drive part of the radiation thickness measuring apparatus of 1st Embodiment. The functional block diagram of a shutter. 6 is a time chart for explaining a shutter control operation. The block diagram of the shutter drive part of the radiation thickness measuring apparatus of 2nd Embodiment. The block diagram of the conventional radiation thickness measuring apparatus.

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

(First embodiment)
The shutter 1 of the radiation thickness measuring apparatus according to the first embodiment will be described with reference to FIGS. 1 to 3.

The shutter 1 provided in the radiation thickness measuring apparatus 100 corresponds to the shutter 10 described with reference to FIG. 5, and the shutter driving unit 5 is provided corresponding to the position of the shutter driving unit 50.

FIG. 1A is a plan view of the shutter driving unit 5, and FIG. 1B is a side sectional view of the rotary solenoid 5 a of the shutter driving unit 5 at the rotation end position.

In the shutter 1 of the first embodiment, the lead plate or the thickness reference sample plate is moved to a position where the rotary solenoid is rotated in one direction to block the radiation passage, and the lead plate or the thickness reference sample plate is reversed in the other direction to emit radiation. The shutter drive unit 5 is moved to a position outside the passage, and the shutter control unit 6 is configured to control the rotation operation of the shutter drive unit.

In FIG. 1, the shutter drive unit 5 is fixed to the rotary shaft 5a1 in a horizontal state in which the axis direction of the rotary shaft 5a1 of the rotary solenoid 5a is provided in the vertical direction and in a horizontal state orthogonal to the axial direction of the rotary shaft 5a1. And a shutter holder plate 5b having a lead plate 5c or a thickness reference sample plate fixed to one end thereof. The rotary solenoid 5a is fixed to a base 5e that houses a shutter 1 (not shown).

Furthermore, a passage detection sensor 5d such as a photosensor or a magnetic sensor for detecting a predetermined deceleration start position for starting deceleration of the rotation speed of the shutter holder plate 5b is provided.

However, it is also possible to set a predetermined time from the rotation start position of the rotary solenoid 5a as the deceleration start position. In this case, the passage detection sensor 5f can be omitted.

Further, the lead plate 5c or the thickness reference sample plate may be fixed to the shutter holder plate 5b by screwing, welding, or fixing using an adhesive and having durability to withstand impact. I just need it.

Then, as shown in FIG. 2, the shutter control unit 6 receives the detection signal s2 corresponding to the deceleration start position from the passage detection sensor 5d, sends the controlled excitation signal s3 to the rotary solenoid 5a, and the sample holder plate The rotation of 5b is decelerated and moved to the rotation end (stop) position.

The shutter opening / closing command signal s1 to the shutter control unit 6 is transmitted every time the shutter opening / closing is required from a controller that controls the thickness measurement provided in the radiation thickness measuring apparatus 100 (not shown).

Further, the shutter controller 5b rotates at a predetermined torque from a rotation start position to a predetermined deceleration start position shown by a broken line in FIG. 1, and the lead plate 5 shown by a solid line in FIG. 1 from the deceleration start position.
Until the center of c becomes the center of the radiation path, the application of the excitation power to the rotary solenoid 5a is decelerated by pulse width modulation for a certain period of time. This pulse width modulated excitation power supply waveform s3
An example is shown in FIG.

In the above description, the rotary solenoid 5a is assumed to be a one-way excitation / spring return type, which will be described later. However, in the case of the bidirectional excitation type, the shutter control unit 5b moves from the rotation end position to the rotation start position. Similar deceleration control is also required for reverse rotation.

Next, the detailed configuration of each unit will be described. There are various types of the rotary solenoid 5a, and the rotary solenoid 5a has a torque for rotating the lead plate 5c and the shutter holder plate 5b for fixing the lead plate 5c at a predetermined rotation speed and a rotation angle capable of covering a required moving range. Any one of the one-way excitation / spring return type and the bidirectional excitation type that switches the excitation direction according to the rotation direction may be used.

The stopper 5f at the stop position may be either a built-in type incorporated in the rotary solenoid 5a itself or an external type not incorporated.

Further, since the shutter holder plate 5b includes the lead plate 5c or the thickness reference sample plate at one end, the other end may be lighter or heavier.

When the other end is lighter, a plate having a weight equivalent to the lead plate 5c is fixed to the other end so that the load on the bearing portion of the rotating shaft 5a1 is in the axial direction, and the radial load is as small as possible. It is desirable to be. In addition, it goes without saying that the whole is light and the moment of inertia is small.

If the thickness reference sample plate is light and the other end is heavier, it is necessary to make the other end lighter. This can be handled by changing the partial shape of the sample holder plate 5b. It is.

For the external stopper 5f, an elastic material is selected so that the impact force at the time of collision is reduced and the bounce at a preset stop position is within an allowable range.

Next, the rotational speed reduction control operation of the shutter 1 configured as described above will be described with reference to FIG. As described above, the pulse width modulation of the excitation power source of the rotary solenoid 5a for deceleration decelerates as a pulse train signal of the period T1 from the predetermined deceleration start position to the rotation end position as shown in FIG. The method.

Further, as shown in FIG. 3 (b), the excitation power source for a predetermined period is turned off from a predetermined deceleration start position, and this moment is rotated by the moment of inertia, and again before the rotation end (stop) position, You may make it stop by applying the set excitation voltage.

That is, any pulse width modulation that can reduce the impact at the rotation end position within the required shutter opening / closing operation time may be used.

According to the thus configured shutter 1 of the radiation thickness measuring apparatus 100 of the first embodiment, the excitation power source of the rotary solenoid 5a is decelerated by pulse width modulation, decelerated from a preset decelerating start position, and then stopped. A fixing portion of the lead plate 5c fixed to the shutter holder plate 5b at the position;
Since the impact on the fixed portion of the thickness reference sample plate and the rotating shaft 5a1 is suppressed,
It is possible to provide a compact and simple shutter 1 of the radiation thickness measuring apparatus 100 in which the impact at the rotation end position of the rotary solenoid 5a is reduced, the bounce is small, and the shutter life is extended.

(Example 2)
Next, a second embodiment of the shutter of the radiation thickness measuring apparatus according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as Example 1, and the overlapping description is abbreviate | omitted.

In the second embodiment, only the lead plate 5c or the thickness reference sample plate is fixed to the shutter holder plate 5b in the first embodiment, but the second embodiment is different from the first embodiment in that the shutter holder The lead plate 5c and the thickness reference sample 5c1 are fixed to the independent sample holder plate 5b on the plate 5b, and the two sample holder plates 5b can be used in the vertical direction at the radiation path position. This is in part 5.

Although FIG. 4 illustrates the case where one thickness reference sample plate 5c1 is stacked in the vertical direction, a plurality of thickness reference sample plates can be obtained by changing the rotary shaft position of the rotary solenoid and the height position where the rotary solenoid is stacked in the vertical direction. It is also easy to do.

According to the shutter 1 of the radiation thickness measuring apparatus 10 of the second embodiment configured as described above, the excitation power source of the rotary solenoid 5a is subjected to pulse width modulation, decelerated from a preset deceleration start position, and at the rotation end position. Since the impact on the fixed portion of the lead plate fixed to the shutter holder plate 5b, the fixed portion of the thickness reference sample plate, and the rotating shaft is suppressed, the impact at the stop position of the rotary solenoid 5a is reduced, and the bounce is reduced. There can be provided the shutter 1 of the radiation thickness measuring apparatus 10 that is small and compact and has a long lifetime.

Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1, 10 Shutter 2 C-type flame | frame 3 Radiation generation part 4 Radiation detector 5, 50 Shutter drive part 5a Rotary solenoid 5b Shutter holder board 5c1 Lead plate 5c2 Sample board 5d Photo sensor 5e Base 5f Stopper 6, 60 Shutter control part 20 Measured Object 100 Radiation thickness measuring device

Claims (4)

A shutter of a radiation thickness measuring device,
The shutter moves the lead plate or the thickness reference sample plate to a position where the rotary solenoid rotates in one direction to close the radiation path, and reverses in the other direction to a position outside the radiation path. A shutter drive unit to be moved, a shutter control unit for controlling a rotation operation of the shutter drive unit,
With
The shutter drive unit, the rotary solenoid provided with a vertical axis of the rotary solenoid;
A shutter holder plate fixed to the rotary shaft in a horizontal state orthogonal to the axial direction of the rotary shaft, and the lead plate or the thickness reference sample plate fixed to one end;
With
The shutter control unit performs pulse width modulation of the excitation power source to the rotary solenoid for a predetermined time from a predetermined deceleration start position to a rotation end position,
In the position where the rotation of the rotary solenoid stops, the lead plate fixed to the shutter holder plate or the fixed portion of the thickness reference sample plate, and the impact on the rotating shaft are suppressed. Radiation thickness measuring device shutter. The shutter of the radiation thickness measuring apparatus according to claim 1, wherein the shutter holder plate has a shape in which the weight of the other end is adjusted such that the position of the center of gravity of the shutter holder plate is the center position of the rotation axis of the rotary solenoid. Furthermore, the shutter drive unit includes a position detection sensor that detects the deceleration start position of the shutter holder plate determined in advance, and the shutter control unit receives the deceleration start position signal and performs a predetermined time The shutter of the radiation thickness measuring apparatus according to claim 1, wherein the excitation power is turned off and the excitation power is turned on before the stop position. The shutter of the radiation thickness measuring apparatus according to claim 1, wherein the deceleration start position is set as a deceleration start position for a predetermined time from the rotation start position of the rotary solenoid.

Images