Concrete core grinding machine

Abstract

We provide a concrete core grinding machine that offers a high recovery rate of concrete powder, improving both work efficiency and safety. [Solution] A concrete core grinding machine (100) comprising a grinder (33) that rotates an abrasive wheel (35) attached to the tip of a rotating shaft (34), and a recovery slope section (40) having a return section (42) along the outer circumference of a plate-shaped section (41) and an opening (44) formed in the plate-shaped section (41), wherein the rotating shaft (34) is inserted into the opening (44) and the grinding surface of the abrasive wheel (35) is exposed on the side of the recovery slope section (40) where the return section (42) is provided.

Description

Technical Field

[0001] The present invention relates to a concrete core grinding machine.

Background Art

[0002] When investigating a concrete structure, in order to grasp the deterioration state due to salt damage in the concrete, a concrete core may be collected as a specimen and a salt content analysis may be performed to measure the salt content in the specimen (see, for example, Patent Document 1). In such a salt content analysis, in order to examine the change in the salt content in the thickness direction of the specimen, the concentration of the salt contained in the concrete powder polished and collected for each thickness position is measured.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the method of pressing a grinding machine against the end face of a core and scraping off the concrete core, it is difficult to collect all the scraped concrete powder, and it is also difficult to obtain the same amount of concrete powder at each thickness. In addition, it has been difficult to achieve both improvement in work efficiency and ensuring the safety of workers.

[0005] In addition, in the method of cutting a concrete core of a specimen into a plurality of parts at a predetermined position in the thickness direction and polishing each part to obtain concrete powder, when cutting into a large number of parts for detailed analysis, there is a problem that the man-hours for cutting and polishing increase and the work efficiency decreases. In addition, since a part of the concrete core is also cut off when cutting the specimen, there is a problem that the amount of recoverable concrete powder decreases as the number of cuts increases.

[0006] Therefore, the present invention has been made in view of the above-mentioned conventional problems, and aims to provide a concrete core polishing machine that has a high concrete powder recovery rate and can improve both work efficiency and safety. [Means for solving the problem]

[0007] To solve the above problems, the concrete core grinding machine of the present invention comprises a grinder that rotates an abrasive wheel attached to the tip of a rotating shaft, and a recovery slope section which has a return portion along the outer circumference of a plate-shaped section and an opening formed in the plate-shaped section, wherein the rotating shaft is inserted into the opening and the grinding surface of the abrasive wheel is exposed on the side of the recovery slope section where the return portion is provided.

[0008] In the concrete core grinding machine of the present invention, the rotating shaft of the grinder is inserted into the opening of the recovery slope section, and the grinding surface of the grinding wheel is exposed on the side of the recovery slope section where the return section is provided. This results in a high recovery rate of concrete powder, improving both work efficiency and safety.

[0009] Furthermore, in one aspect of the present invention, the recovery slope portion has a funnel-shaped portion in which the width of the plate-shaped portion gradually decreases, and a container attachment portion is provided at the tip of the funnel-shaped portion.

[0010] Furthermore, in one aspect of the present invention, a grinder moving unit is provided for moving the grinder and the abrasive wheel in the in-plane direction of the plate-shaped portion.

[0011] Furthermore, in one aspect of the present invention, the radius of the opening is smaller than the maximum rotational radius of the grinding wheel.

[0012] Furthermore, in one aspect of the present invention, the grinder and the recovery slope section are inclined at a predetermined angle with respect to the direction of gravity.

[0013] Furthermore, in one aspect of the present invention, the invention is provided with a tilt angle adjustment unit for adjusting the tilt angle. [Effects of the Invention]

[0014] The present invention provides a concrete core polishing machine that offers a high recovery rate for concrete powder and improves both work efficiency and safety. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic perspective view showing an example of the structure of a concrete core grinding machine 100 according to the first embodiment. [Figure 2] This is a schematic cross-sectional view illustrating the polishing of specimen C using a concrete core polishing machine 100. [Figure 3] This is a schematic diagram illustrating the polishing of the test specimen C and the recovery of concrete powder CP at the recovery slope section 40. Figure 3(a) is a side view, and Figure 3(b) is a top view of the recovery slope section 40. [Figure 4] This is a schematic diagram showing an example of the structure of the recovery ramp section 40. [Modes for carrying out the invention]

[0016] (First Embodiment) Embodiments of the present invention will be described in detail below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. Figure 1 is a schematic perspective view showing an example of the structure of a concrete core grinding machine 100 according to this embodiment. As shown in Figure 1, the concrete core grinding machine 100 comprises a base portion 10, a grinder moving portion 20, a grinding portion 30, a recovery slope portion 40, and a recovery container 50, and grinds a test specimen C. As indicated by the three arrows in the figure, the width direction of the concrete core grinding machine 100 is the x-axis direction, the depth direction is the y-axis direction, and the gravity direction is the z-axis direction.

[0017] Specimen C is a concrete core extracted from a concrete structure to be inspected. Although a cylindrical specimen C is shown in FIG. 1, its shape is not limited. The height direction of specimen C corresponds to the thickness direction from the surface of the concrete structure, and by polishing specimen C in order in the height direction using the concrete core polishing machine 100, concrete powder CP corresponding to the thickness can be obtained.

[0018] The pedestal portion 10 is a member that mounts the concrete core polishing machine 100 on the ground or a workbench and holds the grinder moving portion 20, the polishing portion 30, and the collecting slope portion 40. In the example shown in FIG. 1, the pedestal portion 10 includes a base portion 11, a motor holding portion 12, a shaft holding portion 13, a bypass portion 14, a holding arm portion 15, a mounting table portion 16, a stopper portion 17, and a support column portion 18.

[0019] The base portion 11 is a member for holding each part of the concrete core polishing machine 100, and the back surface side abuts against the ground or the workbench. In FIG. 1, a flat plate-like example is shown as the base portion 11, but the specific shape is not limited. The motor holding portion 12, the shaft holding portion 13, and the stopper portion 17 are attached to the upper surface of the base portion 11.

[0020] The motor holding portion 12 is a member that is attached on the base portion 11 and holds the motor portion 21 described later at a predetermined inclination angle with respect to the base portion 11. Further, it is preferable that the inclination angle of the motor holding portion 12 with respect to the base portion 11 can be adjusted. The structure for adjusting the inclination angle of the motor holding portion 12 is not limited, but for example, the lower end of the motor holding portion 12 may be fixed to the base portion 11 using a hinge or the like, and the inclination angle of the motor holding portion 12 in the yz plane may be made changeable.

[0021] The shaft holding part 13 is a member that is attached on the base part 11 and holds the shaft part 23, which will be described later, at a predetermined inclination angle with respect to the base part 11. Also, bearing parts 24a and 24b, which will be described later, are fixed to the shaft holding part 13. The structure for adjusting the inclination angle of the shaft holding part 13 is not limited, but it is also possible to fix the lower end of the shaft holding part 13 to the base part 11 using a hinge or the like and make it possible to change the inclination angle of the shaft holding part 13 within the yz plane.

[0022] The bypass part 14 is a part that is attached to the upper end side of the shaft holding part 13 and is provided so as to bypass the arrangement space of the polishing part 30. Also, a holding arm part 15 is provided at the upper end of the bypass part 14, and a support column part 18 is attached to the lower surface side. In FIG. 1, an example is shown in which two rectangular parallelepiped-shaped parts are connected at a right angle to form an L-shaped bypass part 14, but the shape is not limited as long as the holding arm part 15 can be extended while avoiding the polishing part 30. Also, in FIG. 1, an example is shown in which the bypass part 14 is configured separately from the shaft holding part 13 and connected, but the shaft holding part 13 and the bypass part 14 may be integrally configured.

[0023] The holding arm part 15 is a part that extends from the bypass part 14 and holds the placement table part 16 facing the recovery slope part 40. One end of the holding arm part 15 is connected to the bypass part 14, and the placement table part 16 is fixed to the upper part of the other end. In FIG. 1, an example is shown in which the holding arm part 15 is configured separately from the bypass part 14 and connected, but the bypass part 14 and the holding arm part 15 may be integrally configured.

[0024] The placement table part 16 is a part that is fixed to the holding arm part 15 and places the test specimen C at a position facing the recovery slope part 40. The structure of the placement table part 16 is not limited, but it preferably has a shape that can place the cylindrical test specimen C movably along the height direction. In FIG. 1, an example is shown in which two plate-shaped members are combined in a V shape. By placing the test specimen C on the placement table part 16 and pressing it against the polishing grindstone 35 exposed in the recovery slope part 40, the end face of the test specimen C is polished by the polishing grindstone 35.

[0025] The stopper portion 17 is a member fixed to the upper surface of the base portion 11 and supporting the lower end of the support column portion 18. The structure of the stopper portion 17 is not limited, but Figure 1 shows an example in which multiple positions in the y-axis direction are provided with a recessed shape extending in the x-axis direction. For simplicity, Figure 1 shows an example of a stopper portion 17 with three recesses, but it may also be formed to be longer in the y-axis direction on the base portion 11 and have more than three recesses.

[0026] The support column 18 is a columnar member whose upper end is attached to the lower surface of the bypass portion 14 and whose lower end abuts against the stopper portion 17. The upper end of the support column 18 is fixed to the bypass portion 14 so as to be rotatable in the yz plane using a hinge or other component. Therefore, the position of the lower end of the support column 18 on the base portion 11 can be changed with the upper end as the pivot point.

[0027] The lower end of the support column 18 contacts the uneven shape of the stopper portion 17, thereby changing the position in the y-axis direction that supports the support column 18 within the plane of the base portion 11, and adjusting the angle of the support column 18 with respect to the base portion 11. This allows adjustment of the inclination angles of the motor holder portion 12, shaft holder portion 13, bypass portion 14, and holding arm portion 15 with respect to the base portion 11. Therefore, the combination of the stopper portion 17 and the support column 18 corresponds to the inclination angle adjustment portion in the present invention. Figure 1 shows the combination of the stopper portion 17 and the support column 18 as the inclination angle adjustment portion, but the configuration is not limited to any structure that can adjust the inclination angles of the motor holder portion 12, shaft holder portion 13, bypass portion 14, and holding arm portion 15 with respect to the base portion 11.

[0028] The grinder moving section 20 is the part that moves the relative position of the grinder 33 with respect to the recovery slope section 40, as will be described later. The grinder moving section 20 includes a motor section 21, a gearbox section 22, a shaft section 23, bearing sections 24a and 24b, and a rotating disc section 25.

[0029] The motor unit 21 is driven by power supplied from a power source and converts electrical energy into rotational motion. The motor unit 21 is attached to the motor holder 12, and its rotating shaft is connected to the gearbox unit 22, transmitting rotational motion to the shaft unit 23 via the gearbox unit 22. The specific structure of the motor unit 21 is not limited, but as torque is more important than rotational speed as will be described later, a portable drill or the like can be used. Also, the method of supplying power to the motor unit 21 is not limited; it may be supplied from outside the concrete core grinding machine 100 using commercial power, or the concrete core grinding machine 100 may be equipped with a secondary battery and power stored therein may be supplied. Furthermore, although the direction of the rotating shaft of the motor unit 21 is shown as the x-axis direction in Figure 1, the direction of the rotating shaft is not limited as long as rotational motion can be transmitted to the shaft unit 23 via the gearbox unit 22.

[0030] The gearbox section 22 is the part to which the rotating shaft of the motor section 21 is connected and which transmits the rotational motion output from the motor section 21 to the shaft section 23. In the example shown in Figure 1, the rotating shaft of the motor section 21 is in the x-axis direction, and the rotating shaft of the shaft section 23 is at an inclined angle in the yz plane, so it is preferable that the gearbox section 22 be equipped with a gear mechanism that can transmit rotational motion with orthogonal rotating shafts. The specific gear mechanism of the gearbox section 22 is not limited, but screw gears, superheterodyne gears, worms and worm wheels, etc., can be used. Furthermore, in order to make the rotational speed of the shaft section 23 less than the rotational speed of the motor section 21, it is preferable that the gearbox section 22 also functions as a reduction gear.

[0031] The shaft portion 23 is a cylindrical member with one end connected to the gearbox portion 22 and the other end to which a rotating disc portion 25 is attached. The shaft portion 23 is inserted into the bearing portions 24a and 24b and is held on the shaft holding portion 13 so as to be rotatable with its central axis in the extension direction as the axis of rotation. The length and diameter of the shaft portion 23 are not limited and an appropriate size can be set according to the size of the concrete core grinding machine 100.

[0032] The bearing portions 24a and 24b are fixed near the lower and upper ends of the shaft holding portion 13, respectively, and are members that rotatably hold the shaft portion 23. The structure of the bearing portions 24a and 24b is not limited, but by inserting the shaft portion 23 into a known bearing structure, the bearings can contact the outer circumference of the shaft portion 23, maintaining rotational motion with low friction. Figure 1 shows an example in which the bearing portions 24a and 24b are provided at two locations, the upper and lower ends of the shaft holding portion 13, but an appropriate number can be used depending on the length and rigidity of the shaft portion 23, and it is possible to provide only one or three or more.

[0033] The rotating disc portion 25 is attached to the other end of the shaft portion 23 and is a plate-shaped disc that rotates in conjunction with the rotational motion of the shaft portion 23. The center of the rotating disc portion 25 coincides with the axis of rotation of the shaft portion 23. The oscillating shaft portion 31 is fixed to the rotating disc portion 25 on the side opposite to the shaft portion 23. The position where the oscillating shaft portion 31 is fixed is between the center and the outer circumference of the rotating disc portion 25.

[0034] The polishing section 30 is held so as to be swingable by the grinder moving section 20 and is the part that polishes the test specimen C. The relative position of the polishing section 30 with respect to the recovery slope section 40 and the test specimen C changes with the operation of the grinder moving section 20. The polishing section 30 comprises a swinging shaft section 31, bearing sections 32a and 32b, a grinder 33, a rotating shaft 34, and a polishing wheel 35.

[0035] The oscillating shaft portion 31 is a cylindrical part with one end attached to the rotating disc portion 25. The oscillating shaft portion 31 rotates around the center of the rotating disc portion 25 as the rotating disc portion 25 rotates. The oscillating shaft portion 31 is also inserted into the bearing portions 32a and 32b, and the bearing portions 32a and 32b also rotate around the center of the rotating disc portion 25.

[0036] The bearing sections 32a and 32b are fixed near one end and the other end of the grinder 33, respectively, and are members that hold the oscillating shaft section 31. The oscillating shaft section 31 is inserted into the bearing sections 32a and 32b, and the bearing sections 32a and 32b are rotatable along the outer circumference of the oscillating shaft section 31. Figure 1 shows an example in which the bearing sections 32a and 32b are provided at two locations, one at one end and the other at the other end of the grinder 33, but an appropriate number can be used depending on the length and rigidity of the oscillating shaft section 31, and it is possible to provide only one or three or more.

[0037] The grinder 33 is the part that rotates the rotating shaft 34 and the grinding wheel 35 using the supplied power. Bearing parts 32a and 32b are attached near one end and near the other end of the grinder 33, respectively. As a result, the grinder 33 is suspended from the oscillating shaft part 31 via the bearing parts 32a and 32b. Therefore, even when the oscillating shaft part 31 moves in a circular motion in conjunction with the rotational motion of the rotating disc part 25, the grinder 33 moves in a circular motion while suspended below the oscillating shaft part 31 by gravity. The specific configuration of the grinder 33 is not limited, but a portable grinder device may be used.

[0038] The rotating shaft 34 is a rod-shaped member with one end connected to the grinder 33 and the other end to which an abrasive wheel 35 is attached. When the grinder 33 is driven by electricity, the rotating shaft 34 rotates around its central axis. The rotational motion of the rotating shaft 34 is transmitted to the abrasive wheel 35. The rotating shaft 34 is also inserted into the opening 44 of the recovery slope section 40, as will be described later.

[0039] The grinding wheel 35 is attached to the tip (other end) of the rotating shaft 34 and rotates in conjunction with the rotation of the rotating shaft 34. The grinding surface of the grinding wheel 35 is exposed to the mounting base 16 side through an opening 44 provided in the recovery slope section 40, which will be described later. As a result, by bringing the test specimen C into contact with the grinding surface of the rotating grinding wheel 35, the test specimen C can be ground and the concrete powder CP can be removed. The shape and structure of the grinding wheel 35 will be described in detail later.

[0040] The recovery slope section 40 is for recovering concrete powder CP from the test specimen C polished in the polishing section 30. In Figure 1, the upper part of the recovery slope section 40 is circumferentially shaped, and its width gradually decreases towards the bottom, but the specific shape is not limited. A recovery container 50 is detachably attached to the lower end of the recovery slope section 40. Details of the recovery slope section 40 will be described later. The material constituting the recovery slope section 40 is not limited, but it is preferable that the removed concrete powder CP does not easily adhere to it, and as an example, metal such as stainless steel can be used.

[0041] The recovery container 50 is a container that can be detachably attached to the lower end of the recovery slope section 40, and is the part that contains the concrete powder CP recovered by the recovery slope section 40. The structure of the recovery container 50 is not limited, but it is preferable that it has a structure that can be attached to the container mounting section 43 of the recovery slope section 40, as will be described later, and one example is a bottle on which a cap can be screwed onto the upper end.

[0042] Figure 2 is a schematic cross-sectional view illustrating the polishing of specimen C using a concrete core polishing machine 100. The y-axis and z-axis directions indicated by arrows in the figure are the same as those shown in Figure 1. For simplicity, only the shaft holding part 13 of the base part 10 is shown in Figure 2, and other parts are omitted from the illustration. Also in Figure 2, the positional changes due to the rotational motion of the grinder 33, rotating shaft 34, and polishing wheel 35 are shown by solid lines and dashed lines.

[0043] As shown in Figure 2, the grinder 33 and the recovery slope section 40 are inclined at a predetermined angle with respect to the direction of gravity, and the angle between the extension direction of the oscillating shaft section 31 and the y-axis direction is θ (0° < θ < 90°). The range of θ is not limited, but in order to bring the test specimen C into contact with the abrasive wheel 35 and to allow the ground concrete powder CP to fall downward due to gravity, it is preferable to set it between 30° < θ < 60°. Furthermore, when adjusting the inclination angle using the inclination angle adjustment section, it is preferable to adjust it so that the inclination angle is between 30 and 60 degrees with respect to the direction of gravity.

[0044] As shown in Figure 2, the recovery ramp section 40 comprises a plate-shaped section 41, a return section 42, a container mounting section 43, and an opening 44. A recovery container 50 is also interchangeably mounted below the container mounting section 43, and the concrete powder CP that slides down the recovery ramp section 40 is collected in the container mounting section 43. Multiple recovery containers 50 are provided, and each time a predetermined amount of concrete powder CP is collected by scraping off the test specimen C in the height direction, the recovery container 50 attached to the container mounting section 43 is replaced.

[0045] The plate-shaped portion 41 is a plate-shaped member that separates the test specimen C from the grinder 33. The plate-shaped portion 41 is provided with a return portion 42 along its outer circumference, a container attachment portion 43 at its lower end, and an opening 44 in part of its surface. As will be described later, below the opening 44, the width of the plate-shaped portion 41 in the x-axis direction gradually decreases, forming a funnel-shaped portion. The funnel-shaped portion also becomes narrower at its lower end, to about the same width as the container attachment portion 43. The surface of the plate-shaped portion 41 on the mounting base portion 16 side is preferably smoothed so that the concrete powder CP obtained by grinding the test specimen C slides off, as will be described later. Figure 2 shows an example in which a plate with a flat cross-section is used as the plate-shaped portion 41, but the shape is not limited as long as the concrete powder CP can slide down, and it may have an uneven or curved cross-section.

[0046] The return portion 42 is a part of the plate-like portion 41 that is folded back along the outer circumference towards the mounting base portion 16. In Figure 2, the cross-sectional shape of the return portion 42 is shown as an arc shape, but the specific shape is not limited. Also, although Figure 2 shows an example in which the plate-like portion 41 and the return portion 42 are formed as one unit by folding back a part of the plate-like portion 41, the plate-like portion 41 and the return portion 42 may be formed as separate parts.

[0047] In the concrete core grinding machine 100, when the test specimen C is ground with the rotating grinding wheel 35, the removed concrete powder CP is scattered outwards from the plate-shaped section 41 by centrifugal force. However, since a return section 42 is provided along the outer circumference of the plate-shaped section 41, the concrete powder CP hits the return section 42 and falls downward, preventing it from flying out of the recovery slope section 40 and improving recovery efficiency.

[0048] The container mounting section 43 is located below the plate-shaped section 41 and is the part to which the collection container 50 is detachably attached. The container mounting section 43 also has a structure that allows the falling concrete powder CP to pass into the interior of the collection container 50. The specific shape of the container mounting section 43 is not limited, but as an example, a cap-shaped fitting with the same diameter and screw groove as the opening of the collection container 50 can be used.

[0049] The opening 44 is an opening formed within the plane of the plate-shaped portion 41, into which the rotating shaft 34 is inserted, exposing the grinding wheel 35 to the mounting base portion 16. The position and size of the opening 44 are not limited, but it must be larger than the range of movement of the rotating shaft 34 accompanying the rotational movement of the grinder 33. Also, if the opening 44 is larger than the grinding wheel 35, there is a higher possibility that concrete powder CP will scatter to the outside from the opening 44, so it is preferable that the radius of the opening 44 is smaller than the maximum rotation radius of the grinding wheel 35.

[0050] In Figure 2, the thickness of the grinding wheel 35 is shown to be larger than it actually is for simplicity, but it is preferable that the grinding surface of the grinding wheel 35 be located close to the surface of the plate-shaped portion 41 so that the concrete powder CP does not scatter to the outside beyond the return portion 42.

[0051] When power is supplied to the motor unit 21, the motor unit 21 transmits rotational motion to the gearbox unit 22, where the rotational speed and direction are converted, causing the shaft unit 23 to rotate. At this time, the shaft unit 23 is pivotally supported by bearing units 24a and 24b fixed to the shaft holding unit 13. In addition, the rotating disc unit 25 also rotates along with the rotation of the shaft unit 23, and the oscillating shaft unit 31 rotates along the circumferential direction of the rotating disc unit 25.

[0052] Since the grinder 33 is suspended from the oscillating shaft 31 by bearings 32a and 32b, the grinder 33 rotates along the circumferential direction of the rotating disc 25 while suspended, as the oscillating shaft 31 rotates. When the grinder 33 rotates, the rotating shaft 34 and the grinding wheel 35 naturally rotate in the same way.

[0053] Furthermore, power is supplied to the grinder 33, causing the rotating shaft 34 and the grinding wheel 35 to rotate around the rotating shaft 34 as the center of rotation. Therefore, the grinding surface of the grinding wheel 35 is exposed on the mounting base 16 side of the recovery slope section 40, and it performs rotational motion along the circumferential direction of the rotating disc section 25 and rotational motion around the rotating shaft 34.

[0054] Figure 3 is a schematic diagram illustrating the polishing of specimen C and the recovery of concrete powder CP at the recovery slope section 40. Figure 3(a) is a side view, and Figure 3(b) is a top view of the recovery slope section 40.

[0055] As shown in Figures 3(a) and 3(b), the operator polishes the test specimen C, which is placed on the mounting base 16, with the concrete core polishing machine 100 by pushing it towards the recovery slope 40. At this time, the bottom surface of the test specimen C comes into contact with the polishing wheel 35 and is polished, and the removed concrete powder CP falls downward into the recovery slope 40. In addition, even if the concrete powder CP is scattered outward along the in-plane direction of the plate-shaped part 41 due to the rotational motion of the polishing wheel 35, the concrete powder CP hits the return part 42 and falls downward. The concrete powder CP that falls into the recovery slope 40 is collected in the funnel-shaped part and stored in the recovery container 50 from the container attachment part 43.

[0056] After polishing the specimen C to the desired thickness, the worker separates the bottom surface of specimen C from the grinding wheel 35, removes the collection container 50 from the container mounting section 43, and covers the collection container 50 with a separately prepared cap. As a result, the collection container 50 collects the amount of concrete powder CP corresponding to the desired thickness. The worker can then attach another collection container 50 to the container mounting section 43 to continue the polishing work on specimen C in subsequent attempts.

[0057] Figure 4 is a schematic diagram showing an example of the structure of the recovery slope section 40. In the example shown in Figure 4, the plate-shaped section 41 has a semicircular shape at the top and a funnel shape that gradually decreases in width towards the bottom, giving it an overall teardrop shape. The opening 44 is a circular shape with the same center as the semicircular shape provided at the top of the plate-shaped section 41. The abrasive wheel 35 has a circular abrasive surface and rotates around a rotating shaft 34 inserted into the opening 44. Furthermore, as the grinder 33 rotates in the circumferential direction of the rotating disc section 25, the abrasive wheel 35 also moves in a circular motion in the in-plane direction of the plate-shaped section 41.

[0058] Figure 4 shows an example where the radius of the opening 44 is smaller than the radius of the grinding wheel 35, and the diameter of the opening 44 is larger than the radius of the grinding wheel 35. However, the diameter of the opening 44 may be smaller than the radius of the grinding wheel 35. In that case, even if the grinding wheel 35 rotates in the in-plane direction of the plate-shaped portion 41, the opening 44 is always covered by the grinding wheel 35, and scattering of concrete powder CP from the opening 44 can be suppressed.

[0059] Furthermore, the diameter of the grinding wheel 35 may be smaller than the diameter of the test specimen C. As described above, the grinding wheel 35 rotates (rotates) around the rotation axis 34 by the grinder 33 and also rotates (revolves) by the grinder moving part 20. Therefore, the area that the grinding wheel 35 can grind is a circle, which is the sum of the diameter of the grinding wheel 35 and the diameter of its revolution. This makes it possible to efficiently grind the bottom surface of the test specimen C with a small area of ​​the grinding wheel 35 and easily remove the concrete powder CP.

[0060] In the concrete core polishing machine 100 of this embodiment, the amount of polishing in the thickness direction of the concrete core, which is the test specimen C, can be adjusted simply by pushing the test specimen C on the mounting table 16 in the direction of the polishing wheel 35 by an appropriate amount. Furthermore, since the bottom surface of the test specimen C is polished with the polishing wheel 35 exposed in the recovery slope section 40 and the concrete powder CP falls into the recovery slope section 40, the scattering of concrete powder CP can be suppressed and the recovery rate can be increased. In addition, the polishing work can be performed simply by placing the test specimen C on the mounting table 16 and pushing the test specimen C along the mounting table 16, improving both work efficiency and safety.

[0061] As described above, in the concrete core grinding machine 100 of this embodiment, the rotating shaft 34 of the grinder 33 is inserted into the opening 44 of the recovery slope section 40, and the grinding surface of the grinding wheel 35 is exposed on the side of the recovery slope section 40 where the return section 42 is provided. This results in a high recovery rate of concrete powder CP, improving both work efficiency and safety.

[0062] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of Symbols]

[0063] 100... Concrete core grinding machine 10…Base 20... Grinder moving part 30...Polishing section 40... Recovery ramp section 50…Collection containers 11…Base 12…Motor holding part 13…Shaft holding part 14...Detour section 15...Holding arm section 16… Mounting platform 17... Stopper Club 18...Strut part 21…Motor section 22...Gearbox section 23… Shaft section 24a, 24b, 32a, 32b… Bearing section 25... Rotating disc section 31...Oscillating shaft section 33... Grinder 34…Rotation axis 35… Sharpening stone 41...Plate-like part 42... Return section 43...Container mounting section 44…Opening

Claims

1. A grinder that rotates by attaching an abrasive wheel to the tip of a rotating shaft, A return portion is provided along the outer circumference of the plate-shaped portion, and a recovery slope portion has an opening formed in the plate-shaped portion. A concrete core grinding machine characterized in that the rotating shaft is inserted into the opening, and the grinding surface of the grinding wheel is exposed on the side of the recovery slope portion where the return portion is provided.

2. A concrete core grinding machine according to claim 1, The aforementioned recovery slope section has a funnel-shaped section in which the width of the plate-like section gradually decreases. A concrete core grinding machine characterized in that a container attachment part is provided at the tip of the funnel-shaped part.

3. A concrete core grinding machine according to claim 1, A concrete core polishing machine characterized by comprising a grinder moving unit that moves the grinder and the abrasive wheel in the in-plane direction of the plate-shaped portion.

4. A concrete core grinding machine according to claim 1, A concrete core grinding machine characterized in that the radius of the opening is smaller than the maximum rotational radius of the grinding wheel.

5. A concrete core grinding machine according to any one of claims 1 to 4, A concrete core grinding machine characterized in that the grinder and the recovery slope section are inclined at a predetermined angle with respect to the direction of gravity.

6. A concrete core grinding machine according to claim 5, A concrete core polishing machine characterized by having an inclination angle adjustment unit for adjusting the aforementioned inclination angle.

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