JP3771343B2 - Nuclear fuel channel material butt face grinding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a channel material constituting a water channel and a channel box of a BWR (boiling water type) fuel assembly, and relates to a grinding apparatus for grinding a butt surface of the channel material.
[0002]
[Prior art]
As shown in FIG. 4, for example, a BWR fuel assembly used for high burnup is provided with a large diameter water channel 22 at the center of a large number of fuel rods 21 and a plurality of spacers 23. The upper tie plate 24 and the lower tie plate 25 are attached to the upper and lower parts, respectively.
[0003]
As shown in FIGS. 5 (a) and 5 (b), the water channel is attached to the square tube portion 26 made of Zircaloy, which is the main body of the water channel 22 and about 4 m long, and above and below the square tube portion 26, respectively. An upper end plug 27 and a lower end plug 28 are provided.
[0004]
As shown in FIG. 6, the rectangular tube portion 26 is formed by abutting a pair of long channel materials C having a U-shaped cross section so as to face each other and welding the abutting surface C ₁ by TIG or laser. It has been produced.
[0005]
After the channel material is press-formed into the U-shaped cross section, it is necessary to make the height dimension of the butt surface uniform with high accuracy in order to improve the dimensional accuracy after the welding and welding. Therefore, the grinding process is performed on the entire longitudinal direction of the butted surfaces.
[0006]
Therefore, conventionally, the channel material has been ground by a plano mirror or a planer (planer), but the channel material is about 4 m as described above, which increases the size of the machine tool. There was a problem such as. That is, as shown in FIG. 7, when the height of the butt surface of the channel material C is ground with a large machine tool such as a planar, the fixing method of the channel material C is a groove carved into a plane as shown in FIG. 29, the channel material C is fitted, and a fixed core 30 is put inside thereof, and several places are held by clamps 31, and tightened and fixed by clamp bolts 32. At the time of grinding, two channel materials C are fixed in parallel and processed by a planar.
In that case, when finishing the abutting surface of the channel material C coming out of the clamp, the fixed clamp 31 must be retightened and the other abutting surface must be ground. There is a problem in management of work efficiency and processing accuracy. In addition, since the planar is configured so that the channel material is sent in the longitudinal direction to the grinding part, the total length is as large as about 10 m, and the equipment cost and running cost are high. However, there is a problem in terms of cost for mass production.
[0007]
[Problems to be solved by the invention]
The present invention has dealt with in practice as described above, and has found a completely new configuration in a butt surface grinding apparatus for a channel material for nuclear fuel. The purpose is to improve the efficiency and accuracy of grinding of the material.
[0008]
[Means for Solving the Problems]
That is, the channel material butt surface grinding apparatus of the present invention suitable for the above-described object is characterized in that, in an apparatus for grinding a butt surface of a channel material having a U-shaped cross section constituting one half of a water channel or a channel box, And a groove that fits and holds the channel material over its entire length in a state in which the butting surfaces on both sides protrude, and a fixing that is formed over the entire length of the channel material and that fits into the groove of the channel material fitted into the groove. A core block, a pressing mechanism that presses the channel material against the bottom of the concave groove portion via the fixed core block, and at least one side wall of the concave groove portion, the channel material pressed by the pressing mechanism a fixing mechanism for fixing over the channel member entire length sandwiches from the side, a fixed channel A machining head provided with a grinding machine that grinds each abutting surface, and a moving mechanism that moves the machining head in the longitudinal direction of the channel material while grinding each abutting surface of the channel material by the grinding machine. There is.
[0009]
[Action]
In the grinding apparatus of the present invention, the channel material is first put in the concave groove portion together with the fixed core block, and the channel material is fixed so as to be sandwiched from the side by the fixing mechanism while being pressed against the bottom portion of the concave groove portion by the pressing mechanism. .
Then, the pressing mechanism is released, and the butted surfaces of the both side walls of the channel material protruding from the concave groove portion are sequentially ground in the longitudinal direction while the grinder is moved by the grinder of the processing head.
[0010]
That is, in the grinding device of the present invention, the channel material is held in the recessed groove portion accurately by the pressing mechanism and the fixing mechanism, but the channel material butting surfaces are released from both the left and right side walls by fixing from the side surface. This makes it possible to simultaneously grind the butted surfaces of the both side walls with a single fixation.
In the apparatus of the present invention, since the grinding machine is moved with respect to the channel material, the entire length of the apparatus can be limited to half the conventional length of the channel material.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0012]
FIG. 1 is a perspective view showing a butt surface grinding apparatus for a water channel channel material according to an embodiment of the present invention, and FIG. 2 is an enlarged view showing a main part of the apparatus.
[0013]
As shown in FIG. 1, the grinding apparatus of the above embodiment is fitted and held on a base 1 and a channel material C made of Zircaloy with the butted surfaces slightly projecting on both sides. The fixed core block 3 to be configured, the pressing mechanism 4 for pressing the channel material C against the bottom 2a of the concave groove portion 2 through the fixed core block 3, and one side wall of the concave groove portion 2 are configured to be pushed in. The channel member C is sandwiched and fixed from the side, a fixing mechanism 5, a processing head 7 provided with a grinding machine 6 for grinding each butted surface of the fixed channel material C, and the grinding machine 6 to make the channel material C And a moving mechanism 8 for moving the processing head 7 in the longitudinal direction of the channel material C while grinding the butted surfaces.
[0014]
In this example, the concave groove portion 2 is formed laterally on the base 1, and is formed so as to fit and hold the outer shape over the entire length of the channel material C. The fixed core block 3 is also formed over the entire length of the channel material C, and is fitted into the groove portion of the channel material C with the both sides of the channel material C slightly protruding as shown in FIG.
[0015]
On the other hand, as shown in FIGS. 1 and 2, the pressing mechanism 4 is composed of a plurality of cylinders 9 disposed so as to face the concave groove portion 2 at a predetermined interval, and the cylinder shaft 9a is shown in FIG. The channel material C is pressed against the bottom portion 2a of the concave groove portion 2 through the fixed core block 3 by projecting to the bottom. At this time, the fixing mechanism 5 does not operate as shown.
[0016]
On the other hand, as shown in FIGS. 2 and 3, the fixing mechanism 5 lifts the clamp plate 10 constituting one side wall of the concave groove 2 and the clamp plate 10 upward so that the channel material C can be easily inserted. A plurality of coil springs 11 and a plurality of clamps for lowering the clamp plate 10 against the coil springs 11 and sandwiching and fixing the channel material C between the clamp plate 10 and the other side wall 2b of the groove 2 And a cylinder 12.
[0017]
That is, the clamp plate 10 of the fixing mechanism 5 is lifted as shown in FIG. 3 when the cylinder shaft 9a of the pressing mechanism 4 presses the channel material C against the concave groove portion 2, and is lowered while the pressing state continues. Then, the channel material is clamped and fixed.
When this fixing is completed, the cylinder shaft 9a is retracted as shown in FIG. 2, and the front of the butt surface of the channel material C is released so that the rotary machining blade 13 of the grinding machine 6 can pass through.
[0018]
Further, the machining head 7 includes a rotary machining blade 13 such as an end mill disposed substantially vertically so that the butt surfaces of the channel material C can be ground simultaneously, and a spindle motor 14 that rotates the rotary machining blade 13. I have.
As shown in FIG. 1, the moving mechanism 8 includes two rail portions 15 installed in parallel to the concave groove portion 2, a ball screw 16 installed in parallel between the rail portions, and the ball screw And a hollow AC servomotor 17 having a nut. The processing head 7 is slidably mounted on the rail portion 15, and is moved along the ball screw 16 by the servomotor 17 with a nut fixed to the lower portion of the processing head 7.
The moving mechanism 8 moves the machining head 7 to the end of the apparatus so that the rotary machining blade 13 does not get in the way when the channel material C is fitted in the groove 2 as shown in FIG. it can.
[0019]
Reference numeral 18 shown in FIG. 1 denotes an NC control panel, which numerically controls the grinding speed, depth of cut, etc. of the grinding device with high precision, and from pressing to fixing the channel material C, and from grinding to unlocking. Is done automatically.
[0020]
Thus, in the grinding apparatus according to the embodiment of the present invention, as shown in FIG. 3, the channel material C is first put into the concave groove portion 2 together with the fixed core block 3 and pressed against the bottom portion 2 a of the concave groove portion 2 by the pressing mechanism 4. In this state, the channel member C is fixed by the fixing mechanism 5 as shown in FIG.
Next, as shown in FIG. 2, the pressing mechanism 4 is released, the cylinder shaft 9 a is retracted, and the abutting surfaces of both side walls of the channel material C protruding from the recessed groove portion 2 are removed by the grinding machine 6 of the processing head 7. As shown in FIG. 1, grinding is sequentially performed in the longitudinal direction while moving the grinding machine 6.
[0021]
That is, in the grinding device of the above-described embodiment of the present invention, the channel material C is fixed by fixing from the side surface while accurately holding the channel material C in the concave groove portion 2 by the action of the pressing mechanism 4 and the fixing mechanism 5. The abutting surfaces can be released on both the left and right side walls, so that simultaneous grinding of the abutting surfaces of the both side walls can be performed automatically with one fixation.
In the apparatus of the present invention, the grinding machine is moved with respect to the channel material. Therefore, the overall length of the apparatus is limited to the length of the channel material C, and can be limited to half the conventional length. is there.
[0022]
As mentioned above, although embodiment of this invention was described, it can be used also as a butt surface grinding apparatus of the channel material for channel boxes by changing the magnitude | sizes of the ditch | groove part of a device, a fixed core block, etc. . In the above-described embodiment, the groove portion is laterally oriented, but can be formed upwardly or downwardly.
[0023]
【The invention's effect】
As described above, the apparatus for grinding a butt surface of a channel material for nuclear fuel according to the present invention is an apparatus for grinding a butt surface of a channel material having a U-shaped cross section that constitutes one half of a water channel or a channel box. A groove is formed on the base, and the channel material is fitted and held over the entire length in a state where the butting surfaces on both sides protrude, and the channel material is formed over the entire length of the channel material and is fitted into the groove of the channel material fitted into the groove. A fixed core block, a pressing mechanism that presses the channel material against the bottom of the concave groove portion through the fixed core block, and a channel material that constitutes at least one side wall of the concave groove portion and is pressed by the pressing mechanism a fixing mechanism for fixing the channel member over the entire length by sandwiching from the side of a fixed channel A machining head provided with a grinding machine for grinding each abutting surface of the material, and a moving mechanism for moving the machining head in the longitudinal direction of the channel material while grinding each abutting surface of the channel material by the grinding machine. It is those having, while retaining exactly contact the channel member in the groove portion over its entire length by the action of the pressing mechanism and the fixing mechanism, the channel member by a reliable fixation of the side surface of the fixing mechanism The abutting surfaces can be released on both the left and right side walls, which makes it possible to simultaneously grind the abutting surfaces of the both side walls with a single fixation, and further, the channel is pressed statically across the channel material. It is possible to grind the material butting surfaces with high accuracy and extremely efficiently, and the grinder is moved with respect to the channel material. Because, it met with total length of the device to approximately the length of the channel member, in which a marked effect of the keep the length of a conventional half.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a butt surface grinding apparatus for a nuclear fuel channel material according to an embodiment of the present invention.
FIG. 2 is an enlarged view showing a main part of the apparatus.
FIG. 3 is an enlarged view of a main part showing an operating state of a pressing part and a fixing part of the apparatus.
FIG. 4 is a cross-sectional view of a BWR fuel assembly.
5A is a front view of a water channel. FIG. (B) It is the sectional view on the AA line of the same figure (I).
FIG. 6 is a perspective view showing a production state of a water channel.
FIG. 7 is a perspective view showing a conventional apparatus for grinding a butt surface of a channel material for nuclear fuel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2 Groove part 2a Bottom part 2b Side wall 3 Fixed core block 4 Pressing mechanism 5 Fixing mechanism 6 Grinding machine 7 Processing head 8 Moving mechanism 9 Cylinder 9a Cylinder shaft 10 Clamp plate 11 Coil spring 12 Clamp cylinder 13 Rotary processing blade 14 Spindle Motor 15 Rail 16 Ball screw 17 Hollow AC servo motor 18 NC control panel C Channel material

Claims (1)

In a device that grinds the butt surface of a channel material with a U-shaped cross section that forms one half of the water channel or channel box, it is formed on the base, and the channel material is fitted over the entire length with the butt surfaces on both sides protruding. A groove portion to be held, a fixed core block that is formed over the entire length of the channel material and is fitted into the groove portion of the channel material that is fitted into the groove portion, and the channel material is inserted into the groove portion through the fixed core block. A pressing mechanism that presses against the bottom portion, a fixing mechanism that forms at least one side wall of the concave groove portion, sandwiches the channel material pressed by the pressing mechanism from the side, and fixes the entire length of the channel material; and a fixed channel material A machining head equipped with a grinding machine that grinds each abutting surface, and the above-mentioned cha While grinding the respective abutting surfaces of the panel member, the butting surfaces grinding device nuclear fuel channel member, characterized in that the processing head and a moving mechanism for moving in the longitudinal direction of the channel member.

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