JPH0447757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a steady rest device that prevents the tip of a core bit of a core boring machine from swinging.

(Prior Art) As is well known, a core boring machine is generally used to collect a core sample to be subjected to a strength test or the like from a workpiece such as concrete or ground.

Core boring machines use a long, cylindrical core bit with a diamond chip embedded in the tip.The base end (upper end) of the core bit is supported and rotated by a motor, etc., and the tip of the core bit is inserted into the workpiece. The hole is drilled by pressing it against the hole.

However, the core boring machines that have been commonly used in the past have a drawback in that they tend to run out at the tip of the core bit. That is, when the core bit is attached to the rotating mechanism that is its drive source, the rotational axis of the rotating mechanism and the axis of the core bit may not match accurately due to the accuracy of the rotating mechanism itself and the accuracy of the connecting parts. In this case, even if the deviation is very small, since the core bit is long, the deviation is amplified at its tip, resulting in a large swing. Therefore, there was a problem in that it was difficult to accurately position the hole to be drilled.

Conventionally, effective and appropriate means such as steady rest devices have not been provided to solve the above problems.
In most cases, a core bit is used to cut a groove in the workpiece, then the core bit is replaced with a longer core bit (usually about 1000 mm), and the hole is drilled using the groove as a guide. However, even if such means are used, it is necessary to rely on the senses of a skilled worker and perform operations such as delicately moving the bit up and down in order to make the first kerf in the correct position.

(Problem to be solved by the invention) By properly using long and short core bits as described above,
Moreover, the work that relied on the senses of a skilled worker was both troublesome and unreliable. In addition, especially when a core boring machine is used by remote control, for example, as previously provided by the present applicants, the reactor can be opened by continuously drilling holes in the reactor shield wall with the core boring machine. When dismantling (Tokugansho
No. 59-165186 and Japanese Patent Application No. 59-165187), etc., it is difficult to replace the core bit in the middle of work, and it is difficult to perform delicate operations that rely on sensation, so the problem of not being able to perform accurate positioning as described above remains. ing.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a steady rest device that prevents the tip of a core bit of a core boring machine from swinging and enables accurate positioning.

(Means for Solving the Problems) The present invention includes at least three rollers that are rotatably supported and contact the outer periphery of the core bit at approximately equal intervals, and a hydraulic cylinder or the like that presses these rollers against the outer periphery of the core bit. The steady rest device main body has a drive mechanism, a hydraulic motor and a guide post that fix the steady rest device main body to the upper surface of the workpiece, and a presser frame is attached to the steady rest device main body. A pair of the guide posts are vertically attached to the presser frame, the hydraulic motor is attached to the tip of the horizontal arm, and a pinion that meshes with the outer surface of the guide post is attached to the rotating shaft of the hydraulic motor. , the steady rest device main body has a cover that houses the drive mechanism and is fixed to the presser frame;
A sealing material that is brought into close contact with the upper surface of the workpiece is attached to the lower surface of the cover.

(Function) The present invention is attached to a core boring machine and functions as follows.

The roller is pressed evenly against the outer periphery of the core bit from at least three directions by its drive mechanism, and counteracts and prevents the swinging force of the core bit.

The hydraulic motor and guide post, which act as a fixing mechanism for the steady rest device body, secure the cover fixed to the presser frame attached to the guide post to prevent the steady rest device body from moving due to the swinging force of the core bit. By fixing it to the top surface, the steady rest device body is firmly fixed, and the sealing member on the bottom surface of the cover is brought into close contact with the top surface of the workpiece, making the fixation even more effective and reliable. .

(Embodiment) An embodiment in which the present invention is attached to a nuclear reactor disassembly robot will be described with reference to FIGS. 1 to 4. Here, the reactor disassembly robot is a core boring machine that is installed inside the cylindrical reactor wall and has a horizontal arm that can move up and down, left and right, and back and forth. Using a grinding and cutting machine, the inner part of the damp wall is cut into blocks and dismantled by remote control. This is a device previously provided by the present applicants (Japanese Patent Application No. 1983-
No. 165186).

1 to 4 are diagrams showing the overall schematic structure of this embodiment, and reference numeral 1 in the figures indicates a horizontal arm of the above-mentioned nuclear reactor dismantling lot (the main body is not shown). A core boring machine 2 is mounted at the center of the tip of the horizontal arm 1. The core boring machine 2 consists of a long and cylindrical core bit 3 and a motor 4 that supports the base end (upper end) of the core bit 3 and rotates it, and the core boring machine 2 is made of a long and cylindrical core bit 3 and a motor 4 that supports and rotates the base end (upper end) of the core bit 3. Core boring is performed more vertically. That is, the horizontal arm 1 gradually descends from above the stiff wall 5, presses the tip (lower end) of the core bit 3 against the upper surface of the stiff wall 5, and sends it to the top of the stiff wall 5 to form a cylindrical shape. After the cutting operation is completed, the horizontal arm 1 rises to take out the core. Cooling water for cooling the tip of the core bit 3 is sent to the motor 4 through the supply pipe 6 from a cooling water supply device (not shown), and the cooling water descends inside the core bit 3 and is sent to the tip of the core bit 3. ing.

A core bit resting device 7 is provided at the tip of the horizontal arm 1. The core bit steady rest device 7 is composed of a steady rest device main body 8, hydraulic motors 9, 9, and guide posts 10, 10 that fix the steady rest device main body 8 to the upper surface of the stiff wall 5. . That is, presser frames 11, 11 are attached to the steady rest device main body 8, and a pair of guide posts 1 are installed perpendicularly to the presser frames 11, 11.
0 and 10 are attached. Guide post 1
0 and 10, a fixing member 12 is horizontally fixed between their upper ends. Also, guide posts 10, 10
has a rack (spur gear) 13 on its outer surface.
13 are attached to each. Pinions 14, 14 attached to the rotating shafts of the hydraulic motors 9, 9 mesh with the racks 13, 13. The hydraulic motors 9, 9 are attached to frames 15, 15 fixed to both sides of the horizontal arm 1 so as to protrude forward. The pedestal 1
5 and 15 have holes 1 provided on their lower surfaces.
6 and 16 are inserted through the guide posts 10 and 10 with a gap therebetween. Note that the hydraulic motors 9, 9 mentioned above are equipped with a drain port. A hydraulic motor with a drain port has a function in which the rotation of the rotation shaft stops when an external force of a certain level or more is applied to the rotation shaft, but a constant torque can be maintained even at this time.
(In other words, these hydraulic motors 9, 9
When the oil supplied from the drain pipe 18 is returned through the oil return pipe 18, its rotating shaft rotates, but if an external force of more than a certain level is applied to the rotating shaft, the oil is returned through the drain pipe 19. A constant torque is maintained when the rotating shaft is stopped. ) Also, the above mount 1
Bearings 20, 20 that slide inside the guide posts 10, 10 are attached to the pinions 5, 15 at positions facing the pinions 14, 14 with the guide posts 10, 10 in between.

Based on the above configuration, this hydraulic motor 9, 9
The guide posts 10 and 10 act as a fixing mechanism for the steady rest device main body 8. That is, by rotating the rotation shafts of the hydraulic motors 9, 9 (the rotation directions of the two hydraulic motors 9, 9 are opposite to each other), the pinion 14 and the rack 13 are rotated.
By the action of the bearing 20, the steady rest main body 8 moves up and down with respect to the horizontal arm 1, and when the core boring machine 2 is drilling (the horizontal arm 1 descends and the core bit 3 is sent downward). ), the hydraulic motor 9,9
The steady rest device main body 8 is pressed against the upper surface of the stiff wall 5 by the torque of (at this time, the hydraulic motor 9
The rotation axis of the horizontal arm 1 is rotated in the opposite direction to the direction in which the torque is applied. ), the steady rest device main body 8 is firmly fixed to the upper surface of the stiff wall 5 due to the rigidity of the guide posts 10, 10 and the frictional force generated between the stiff wall 5 and the top surface of the steady rest device main body 8. That will happen.

Next, the steady rest device main body 8 is constituted by a cooling water scattering prevention cover 21, a core bit steady rest mechanism provided inside the cover 21 (details will be described later), and a hydraulic cylinder 22. The cooling water scattering prevention cover 21 is a hollow box having an arcuate portion at the front when viewed from above, and is connected to the bottom plate 2.
3. Top plate 24, peripheral side plate 25, and rear side plate 26
It is formed by. The bottom plate 23 and the top plate 24 are each provided with a hole having a diameter slightly larger than the outer diameter of the core bit 3. Further, a sealing material 27 having elasticity such as rubber is attached to the entire outer surface of the bottom plate 23 (the lower surface of the cooling water scattering prevention cover 21) except for the above-mentioned hole portions.
Furthermore, the rear side plate 26 includes a cooling water outlet 28,
28 is provided, and cooling water recovery pipes 29, 29 that lead the cooling water to a recovery device (not shown) are connected to the cooling water discharge ports 28, 28. The cooling water scattering prevention cover 21 having the above structure has the core bits 3 inserted into the holes of the bottom plate 23 and the top plate 24.
It is fixed to the presser frames 11, 11.

As a result, the cooling water scattering prevention cover 21 is lowered inside the core bit 3 and sent to the tip of the core bit 3 by the motor 4 of the core boring machine 2 mentioned above, and the cooling water contaminated with radioactivity flows out of the cover 21. While preventing the cooling water from scattering, the cooling water stored in the cover 21 is discharged from the cooling water outlet 28 to the recovery device. Here, the sealing material 27 attached to the lower surface of the cover 21 is pressed against the upper surface of the flexible wall 5 by the torque of the hydraulic motors 9 and is in close contact with the upper surface of the flexible wall 5, so that no accumulation occurs within the cover 21. Cooling water will not flow out of the cover 21.

Rear side plate 2 of the above cooling water scattering prevention cover 21
6, the hydraulic cylinder 22 is attached. Oil supply pipes 30 and 31 are connected to the hydraulic cylinder 22 to a drive source device (not shown). The piston rod 32 of the hydraulic cylinder 22 passes through the rear side plate 26, and its tip is fixed to a triangular cam 34 via a buffer member 33, as shown in FIG. The triangular cam 34 is an isosceles triangle in plan view, and the piston rod 32 is fixed to the center portion of the rear end surface. Also, triangular cam 34
A roller 35 is rotatably attached to the apex of the roller 35 via a support member. Triangular cam 34
is arranged so that the roller 35 is pressed against the outer periphery of the core bit 3 when the piston rod 32 of the hydraulic cylinder 22 extends forward (in the X direction in the figure). In addition, a hole 36 is provided on the rear end surface of the triangular cam 34.
36 is provided, and the rear side plate 2 is inserted into the holes 36, 36.
The rod-shaped cam guide shafts 37, 37 attached to the triangular cam 3 are slidably inserted into the triangular cam 3.
4 is made to move smoothly.

Further, on the two slopes (two surfaces excluding the rear end surface) of the triangular cam 34, auxiliary rollers 39, 3 are rotatably supported at one end of the steady rest levers 38, 38.
9 is in contact. Steady rest lever 38, 38
is a rod-shaped member having a bent part, the bent part is rotatably supported by shafts 40, 40 fixed to the bottom plate 23, and is placed inside the cooling water scattering prevention cover 21 with respect to its center line. arranged symmetrically. The above-mentioned auxiliary rollers 39, 39 are attached to one end of the steady rest levers 38, 38, and rollers 41, 41 are rotatably supported at the other end via a support member. Also, steady rest lever 3
8 and 38 have coiled springs 42 and 42, one end of which is supported by a pin 43 fixed to the bottom plate 23, and the other end supported by a pin 44 fixed near the rollers 41 and 41 of the steady rest levers 38 and 38, respectively. It is provided.

As a result, the steady rest levers 38, 38 are connected to the piston rod 3 of the hydraulic cylinder 22 as described above.
2 extends and the triangular cam 34 is pushed forward (in the X direction in the figure), and when the roller 35 at the tip of the triangular cam 34 comes into contact with the core bit 3, the auxiliary roller 3
9, 39 are pushed by the slope of the triangular cam 34, and rotate in the Y direction in the figure about the shafts 40, 40 (note that the two steady rest levers 38, 3
8 rotate in opposite directions. ) Therefore, the rollers 41, 41 are pressed against the outer periphery of the core bit 3. Here, the rollers 35, 4
1 and 41 are pressed with equal force to positions that roughly divide the outer periphery of the core bit 3 into three equal parts. Also, the piston rod 32 of the hydraulic cylinder 22 returns to the triangular cam 34.
When the levers move backward, the steady rest levers 38, 38 are rotated in the opposite direction by the action of the coil springs 42, 42 and returned to their original positions, so that they are separated from the core bit 3.

Based on the above configuration, in this core bit steady rest device 7, the rollers 35, 41, 41 press the core bit 3 evenly from three directions to prevent the core bit 3 from swinging, and to perform accurate drilling positioning. Become. Here, rollers 35, 41, 4
Since the core bit 1 is rotatably supported, there is no resistance to the rotation of the core bit 3.
Further, since the steady rest device main body 8 is firmly fixed by being pressed against the upper surface of the stiff wall 5, the main body 8 does not move due to the swinging force of the core bit 3. Here, the buffer member 33 absorbs minute vibrations of the triangular cam 34 caused by the swinging force of the core bit 3, and also prevents sudden impact from being applied to the hydraulic cylinder 22. (In addition, the buffer member 33
Therefore, it is desirable to use a disc spring. ) Furthermore, the cooling water scattering prevention cover 21 prevents cooling water contaminated with radioactivity from scattering around.

Next, how to use this core bit steady rest device 7 will be explained. First, core boring machine 2
While the reactor is stopped, operate the reactor disassembly robot to move the horizontal arm 1 and remove the core bit 3.
guide the tip of the hole to the correct drilling position. Next, the hydraulic motors 9, 9 are rotated to lower the steady rest device main body 8 and press it against the upper surface of the stiff wall 5. When the steady rest device main body 8 is pressed against the upper surface of the stiff wall 5 with a constant force, the rotation of the hydraulic motors 9, 9 is stopped, but the torque of the hydraulic motors 9, 9 is maintained. Next, the hydraulic cylinder 22 is driven to move the rollers 35, 41, 41 to the core bit 3.
cooling water is supplied through the supply pipe 6, and the motor 4 of the core boring machine 2 is driven to rotate the core bit 3. So horizontal arm 1
By gradually lowering the core bit 3, the tip of the core bit 3 can drill at an accurate position without wobbling. At this time,
The cooling water is collected from inside the cooling water scattering prevention cover 21 through the cooling water collection pipe 29 to the collection device. When drilling to the scheduled depth is completed, the motor 4 is stopped, the cooling water supply is stopped, and the hydraulic cylinder 22 is stopped.
The piston rod 32 of the roller 3 is moved backward.
5, 41, 41 are separated from the core bit 3, the horizontal arm 1 is raised and the core bit 3 is taken out. The cut core can then be extracted from the stiff wall using an appropriate means. All of the above operations are performed by remote control.

Note that after the core bit 3 makes the first cut groove in the flexible wall 5, this serves as a guide and the core bit 3 hardly shakes, so even if the rollers 35, 41, 41 are separated at this point, good.

(Effects of the Invention) As described above in detail, according to the present invention, the steady rest device main body can be firmly fixed to the upper surface of the workpiece by the hydraulic motor and guide post that act as a fixing mechanism. Moreover, the sealing member on the lower surface of the cover of the steady rest device main body allows the steady rest main body to be fixed even more effectively and reliably. This has the effect of effectively preventing the tip of the core bit of the core boring machine from wobbling and making it possible to accurately position the hole.

[Brief explanation of the drawing]

1 to 4 are diagrams showing a schematic configuration of an embodiment of the present invention. Fig. 1 is an overall perspective view of this embodiment, Fig. 2 is a side view, Fig. 3 is a plan view (however, the main part is a plan cross-sectional view taken from Fig. 2), and Fig. 4 is a front view. . 2... Core boring machine, 3... Core bit,
7... Core bit steady rest device, 8... Steady rest device main body, 9... Hydraulic motor (fixing mechanism), 1
0... Guide post (fixing mechanism), 22... Hydraulic cylinder, 35, 41... Roller.

Claims (1)

[Claims] 1. It is attached to a core boring machine that supports the base end of a long, cylindrical core bit, rotates the core bit, is mounted on the tip of a horizontal arm that can be raised and lowered, and drills into workpieces such as concrete. , a device for preventing the tip of the core bit from wobbling, which includes at least three rollers that are rotatably supported and contact the outer periphery of the core bit at approximately equal intervals, and a drive such as a hydraulic cylinder that presses these rollers against the outer periphery of the core bit. a steady rest device main body having a mechanism, a hydraulic motor and a guide post for fixing the steady rest device main body to the upper surface of the workpiece, and a presser frame is attached to the steady rest device main body. A pair of the guide posts are vertically attached to the presser frame, the hydraulic motor is attached to the tip of the horizontal arm, and a pinion that meshes with the outer surface of the guide post is attached to the rotating shaft of the hydraulic motor. The steady rest device main body has a cover that houses the drive mechanism and is fixed to the presser frame, and a sealing material that is brought into close contact with the upper surface of the workpiece is attached to the lower surface of the cover. Features: Core bit steady rest device for core boring machines.