Grinding wheel balance adjusting tool and grinding wheel balance adjusting method

Abstract

To provide a balance adjusting tool of a grinding wheel and a balance adjusting method of the grinding wheel capable of quickly and highly accurately grasping an unbalance point of the flanged grinding wheel.SOLUTION: A balance adjustment tool 10 for a flanged grinding wheel includes a base 11, a pair of support columns 12 extending vertically upward from a surface of the base 11 and each having a load support portion 121 formed at a tip thereof, an arbor 13 inserted into the spindle insertion hole, and a pair of bearings 14 provided at both ends of the arbor 13, supported by the load support portions 121, and rotatably holding the flanged grinding wheel.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a grindstone balancing tool and a grindstone balancing method. [Background technology]

[0002] Conventionally, grinding wheels used in grinding machines and the like can have a misalignment of the center of gravity between the grinding machine's spindle and the grinding wheel. This is because the grinding wheel is a sintered body, and abrasive grains become uneven during manufacturing, causing a misalignment of the grinding wheel's center of gravity and the center of rotation on its outer surface. If grinding is performed with the grinding machine's spindle and the grinding wheel's center of gravity misaligned, vibrations will occur in the grinding machine during grinding, causing chatter on the ground surface.

[0003] For this reason, Patent Document 1 discloses a method for adjusting the balance of a grinding wheel. Specifically, first, a flanged grinding wheel is assembled by clamping the grinding wheel between a nut (adjustment flange) and a fixing flange. The nut (adjustment flange) has a circumferential groove for attaching a balance piece. Next, an arbor is inserted through the center of rotation of the flange, and the flanged grinding wheel is swung on, for example, a parallel bar balance adjustment table. The flanged grinding wheel stops swung when its center of gravity is positioned vertically downward.

[0004] Once the swinging motion has stopped, the first balance piece is fixed vertically above the circumferential groove of the flange. Furthermore, the second and third balance pieces are temporarily attached to positions on the circumferential groove to the left and right of the fixed position of the first balance piece, for example, 90 degrees to the left and 90 degrees to the right. In this state, the center of gravity of the flanged grinding wheel is moved upward, and the combined assembly is swung again. Finally, the swinging of the flanged grinding wheel and the position adjustment of the second and third balance weights are repeated until the combined assembly begins to roll on the pair of parallel bars without stopping, and the center of gravity is deemed to be aligned with the center of rotation. The second and third balance pieces are then fixed, and the grinding wheel balance adjustment is complete. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 01-171759 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method for adjusting the balance of a grinding wheel described in Patent Document 1 involves inserting an arbor into a flanged grinding wheel and swinging the combined body on a pair of parallel rods, which results in a slow response and makes it impossible to quickly and accurately check the deviation (unbalanced point) between the center of the rotation axis and the center of gravity.

[0007] An object of the present invention is to provide a grinding wheel balancing tool and a grinding wheel balancing method that can quickly and accurately determine the unbalanced point of a flanged grinding wheel. [Means for solving the problem]

[0008] The grinding wheel balancing tool of the present invention is a grinding wheel balancing tool that adjusts the balance of a flanged grinding wheel, which has a grinding wheel and a pair of flanges that clamp the grinding wheel and have a spindle insertion hole formed at the center of rotation into which a machine tool spindle is inserted, and is equipped with a base, a pair of support pillars that extend vertically upward from the surface of the base and have load support portions formed at their tips, an arbor that is inserted into the spindle insertion hole, and a pair of bearings that are provided at both ends of the arbor and supported by the load support portions, and that hold the flanged grinding wheel rotatably.

[0009] The method for balancing a grinding wheel according to the present invention is a method for balancing a flanged grinding wheel comprising a grinding wheel and a pair of flanges that clamp the grinding wheel and have a spindle insertion hole formed at the center of rotation through which a spindle of a machine tool is inserted, and comprises the steps of inserting an arbor into the spindle insertion hole, attaching bearings to each end of the arbor, supporting each of the bearings on a horizontal surface and swinging the flanged grinding wheel, and marking unbalanced points of the flanged grinding wheel on at least one side of the grinding wheel and the flange after the swinging of the flanged grinding wheel has stopped. [Effects of the Invention]

[0010] According to the present invention, since the arbor is supported via a bearing, the flanged grinding wheel can be oscillated with reduced sliding resistance, thereby enabling the unbalance point of the flanged grinding wheel to be determined quickly and accurately. Furthermore, after the flanged grinding wheel stops oscillating, the unbalance point of the flanged grinding wheel is marked. This allows the flanged grinding wheel to be marked on the machine tool according to the unbalance point of the flanged grinding wheel. Therefore, even if the flanged grinding wheel is removed from the spindle and then reattached, the marked unbalance point can be used as a marker, and the flanged grinding wheel can be attached to the spindle without further balance adjustment. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a state in which a flanged grinding wheel is attached to a machine tool according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the structure of a nut of the flanged grindstone according to the embodiment. [Figure 3] 1 is a perspective view showing the structure of a grindstone balance adjuster according to an embodiment of the present invention; [Figure 4] FIG. 2 is a perspective view showing the structure of a bearing according to the embodiment. [Figure 5]FIG. 2 is a cross-sectional view showing the structure of a bearing according to the embodiment. [Figure 6] 1 is a perspective view showing a state in which a flanged grindstone is attached to a grindstone balance adjuster according to an embodiment. FIG. [Figure 7] 10 is a flowchart showing a method for adjusting the position of a grindstone according to an embodiment. [Figure 8] 10A and 10B are schematic diagrams illustrating a method for marking an unbalanced point in the embodiment. [Figure 9] FIG. 2 is a schematic diagram showing a state in which marking is made on a spindle of a machine tool according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a flanged grinding wheel 3 to be adjusted according to an embodiment of the present invention attached to a spindle 2 of a machine tool 1. The machine tool 1 is a grinding machine that grinds the surface of a workpiece, and performs grinding operations by attaching the flanged grinding wheel 3 to the spindle 2, which serves as the rotation axis, and fastening it in place with a clamping screw 2A. The spindle 2 is formed with a truncated conical tapered surface whose diameter gradually decreases toward the tip of the spindle 2, and the rotation axis of the truncated conical tapered surface coincides with the rotation axis of the spindle 2.

[0013] The flanged grinding wheel 3 includes a grinding wheel 4, a fixed flange 5, and a flange (hereinafter simply referred to as a nut) 6 that serves as a nut. The pair of fixed flanges 5 and nut 6 are fixed together with multiple fixing screws 7 to clamp the grinding wheel 4. The fixed flange 5 has a tapered surface 5A that gradually expands in diameter toward the tip in the insertion direction. By inserting the fixed flange 5 into the spindle 2 and abutting the tapered surface of the spindle 2 with the tapered surface 5A of the fixed flange 5, the center of rotation of the flanged grinding wheel 3 can be aligned with the rotation axis of the spindle 2.

[0014] The nut 6 is provided on the surface opposite to the surface where the fixing flange 5 clamps the grinding wheel 4, and functions as a balancer that adjusts the rotation center and center of gravity of the flanged grinding wheel 3. As shown in Figure 2, the nut 6 is made of a circular metal plate, with a spindle insertion hole 6A formed at the rotation center and multiple fixing screw insertion holes 6B formed surrounding the spindle insertion hole 6A. A circular groove 6C is formed on the outer periphery of the nut 6, and a balance piece 8 for balance adjustment is fixed in this groove 6C.

[0015] The reason for fixing the balance piece 8 within the groove 6C is that when the grinding wheel 4 is manufactured, the abrasive grains of the grinding wheel 4 segregate, causing a misalignment between the center of rotation of the grinding wheel 4 and the center of gravity of the grinding wheel 4, so the center of rotation and the center of gravity are aligned to prevent vibration from occurring in the flanged grinding wheel 3 when the flanged grinding wheel 3 is attached to the spindle 2 of the machine tool 1 and rotated.

[0016] 3 shows a flanged grinding wheel balancing tool 10 according to an embodiment of the present invention. The balancing tool 10 is a device for adjusting the static balance of a flanged grinding wheel 3, and includes a base 11, a support column 12, an arbor 13, a bearing 14, and a marker holder 15. The base 11 includes a substantially pentagonal base body 111 and legs 112 provided along the edges of the pentagon of the base body 111.

[0017] The base body 111 is made of a metal, approximately pentagonal plate-like body and has a slide groove 113 that extends from the vertex of the pentagon toward the edge where the leg parts 112 are provided. A slide base 114 slidably engages with the slide groove 113, and the slide base 114 is fixed at any position on the slide groove 113 with screws 115. The legs 112 are fixed to the underside of the base body 111 with screws 116. Level adjustment screws 117 are threadedly engaged with the vertices of the pentagon of the base body 111 and both ends of the legs 112. By adjusting the threaded position of the level adjustment screws 117, the level adjustment screws 117 protrude from the undersides of the base body 111 and the legs 112, allowing the top surface of the base body 111 to be adjusted to a horizontal plane.

[0018] A pair of support columns 12 are provided on the upper surface of the base body 111, one of which extends vertically upward from the edge where the legs 112 are provided, and the other of which extends vertically upward from the upper surface of the slide pedestal 114. A load support portion 121 consisting of a V-shaped recess is formed at the upper end of each support column 12. The pair of support columns 12 are arranged facing each other, and a load support portion 121 is formed at the vertical tip of each support column 12. When the slide pedestal 114 on which the other support column 12 is provided is moved within the slide groove 113, the pair of support columns 12 can be moved closer to or farther apart, allowing for adaptation to various width dimensions of the flanged grinding wheel 3.

[0019] An arbor 13 is installed between the pair of support columns 12 via bearings 14. The arbor 13 is made of a solid metal round bar, and a bulge 131 is formed in the middle of its length. The outer peripheral surface of the bulge 131 is a tapered surface in the shape of a truncated cone, and the rotation axis of the truncated cone coincides with the rotation axis of the arbor 13. The tapered surface 5A of the fixed flange 5 of the flanged grinding wheel 3 abuts against the bulge 131, and when the arbor 13 is inserted into the fixed flange 5 of the flanged grinding wheel 3, the rotation axis of the arbor 13 and the rotation axis of the flanged grinding wheel 3 coincide.

[0020] Bearings 14 are provided on both ends of the arbor 13 to rotatably support the arbor 13. Each bearing 14 is supported by the load support portion 121 of the support column 12 and rotatably supports the flanged grinding wheel 3 in a state where it is floating above the base 11. The bearings 14 are ball bearings and, as shown in FIGS. 4 and 5 , include an outer ring 141, an inner ring 142, and balls 143. The outer ring 141 is made of a metal ring-shaped body, and has multiple recesses formed on its inner circumferential surface to accommodate the balls 143. The inner ring 142 is made of a metal ring-shaped body with a smaller diameter than the outer ring 141, and has multiple recesses formed on its outer circumferential surface to accommodate the balls 143. A plurality of balls 143 are provided between the outer ring 141 and the inner ring 142, and rotatably support the inner ring 142 with reduced sliding resistance relative to the outer ring 141. If necessary, a lubricant such as grease may be injected into the gap between the outer ring 141 and the inner ring 142 to further reduce sliding resistance.

[0021] In this type of bearing 14, the outer peripheral surface of the outer ring 141 is supported by the load support portion 121 of the support column 12, and the arbor 13 is inserted into the inner peripheral surface of the inner ring 142. When the arbor 13 rotates, the inner ring 142 rotates accordingly, and the outer ring 141 can hold the arbor 13 without moving it by means of a plurality of balls 143. Note that in this embodiment, a ball bearing is used as the bearing 14, but the present invention is not limited to this. For example, a roller bearing or an air bearing may be used as the bearing.

[0022] Returning to FIG. 3 , a marker holder 15 is provided on the other of the pair of support columns 12 along the extension direction of the support column 12. The marker holder 15 is formed in the shape of a metal rod and is attached so as to be able to slide freely along the vertical direction, which is the extension direction of the support column 12. A marker attachment part 151 for attaching a marker such as an oil-based pen is formed at the upper vertical end of the marker holder 15. The marker attachment part 151 is a V-shaped recess cut out from the upper end of the marker holder 15. By placing a marker pen or the like on the marker attachment part 151, it is possible to mark imbalance points of the flanged grinding wheel 3 on the side of the grinding wheel 4 of the flanged grinding wheel 3 or on the side of the nut 6.

[0023] 6 shows the flanged grinding wheel 3 set in the balance adjustment tool 10. An arbor 13 is inserted into the nut 6 of the flanged grinding wheel 3, and bearings 14 are attached to both ends of the arbor 13. The bearings 14 attached to both ends are placed on the upper ends of the support columns 12, and the arbor 13 is installed between the pair of support columns 12. In this way, the flanged grinding wheel 3 is rotatably held on the support columns 12.

[0024] Next, a method for adjusting the balance of the flanged grinding wheel 3 according to this embodiment will be described with reference to the flowchart shown in Fig. 7. In this embodiment, as shown in Fig. 2, the flanged grinding wheel 3 is adjusted for balance using three balance pieces 8 on the nut 6, but the number of balance pieces 8 is not limited to this and may be two, three or more. Before adjusting the balance of the flanged grinding wheel 3, the flanged grinding wheel 3 is attached to the spindle 2 of the machine tool 1, and the flanged grinding wheel 3 is rotated to true the grinding wheel 4. By truing, the center of rotation of the grinding wheel 4 is aligned with the centers of rotation of the fixed flange 5 and the nut 6.

[0025] The amount of protrusion of the level adjustment screw 117 is adjusted to adjust the upper surface of the base 11 to a horizontal plane (step S1). Next, the arbor 13 is inserted into the flanged grinding wheel 3 (step S2). Subsequently, bearings 14 are attached to both ends of the arbor 13 (step S3). The bearings 14 on both ends are placed on the upper ends of the support columns 12 (step S4). In this state, the flanged grinding wheel 3 is oscillated (step S5), and the process waits until the oscillation stops.

[0026] When the swinging stops, the first balance piece 8 is fixed at a position vertically above the groove 6C of the nut 6 of the flanged grindstone 3 (step S6). In this state, the vertically above position is marked as an unbalance point (step S7). Specifically, as shown in Fig. 8, a marker 152 made of oil-based ink or the like is attached to a marker attachment portion 151 at the upper end of the marker holder 15, and the marker 152 is slid to mark a mark MK1 on the side of the grindstone 4 and a mark MK2 on the side of the nut 6.

[0027] Next, the second balance piece 8 and the third balance piece 8 are temporarily fastened (step S8). With the first balance piece 8 fixed, the second balance piece 8 and the third balance piece 8 are moved within the groove 6C of the nut 6, and the relative positions of the second balance piece 8 and the third balance piece 8 with respect to the first balance piece 8 are adjusted (position adjustment) (step S9). After adjusting the relative positions, the flanged grindstone 3 is oscillated again (step S10), and it is determined whether the oscillation stops (step S11). If the oscillation stops (step S11: Y), steps S9 and S10 are repeated. When the oscillation of the flanged grindstone 3 does not stop (step S11: N) and the rolling continues, the balance adjustment of the flanged grindstone 3 is completed.

[0028] After the balance adjustment is complete, the flanged grinding wheel 3 is attached to the spindle 2 of the machine tool 1 (step S12). After the flanged grinding wheel 3 is attached, the spindle 2 is marked with an oil-based marker or the like (step S13). Specifically, as shown in FIG. 9, mark MK3 is placed on the tip of the spindle 2 of the machine tool 1. The position of mark MK3 corresponds to the positions of marks MK2 and MK3 on the flanged grinding wheel 3. For example, it is preferable to place mark MK3 at a position where marks MK1 and MK2 are vertically aligned. After the marking is complete, the machine tool 1 is started, and grinding begins. Note that by marking mark MK4 at a fixed position on the machine tool 1 and marking mark MK5 at a position that rotates with the rotation of the spindle 2, the initial position of the spindle 2 can be adjusted when attaching the flanged grinding wheel 3 to the spindle 2.

[0029] This embodiment has the following advantages: Since the arbor 13 is supported via the bearings 14, the flanged grinding wheel 3 can be oscillated with reduced sliding resistance, and therefore the unbalance point of the flanged grinding wheel 3 can be detected quickly and with high accuracy.

[0030] After the flanged grinding wheel 3 stops oscillating, the unbalance points of the flanged grinding wheel 3 are marked as marks MK1 and MK2. As a result, mark MK3 can be marked on the tip of the spindle 2 in accordance with the unbalance points of the flanged grinding wheel 3, so even if the flanged grinding wheel 3 is removed from the spindle 2 and then reattached, the marked unbalance points can be used as a guide, and the flanged grinding wheel 3 can be attached to the spindle 2 without further balance adjustment. In particular, if mark MK4 is marked at a fixed position on the machine tool 1 and mark MK5 at a position that rotates with the rotation of the spindle 2, the flanged grinding wheel 3 can be attached at the initial position of the rotation of the spindle 2, reducing misalignment of the attachment position and suppressing the generation of vibration.

[0031] The present invention is not limited to the above-described embodiment, and may include modifications such as those described below. In the above-described embodiment, the nut 6 of the flanged grinding wheel 3 and the grinding wheel 4 are marked with an oil-based marker or the like, but the present invention is not limited to this. Marking may be done with oil-based paint or a marking sticker or the like. In addition, the specific shape and structure when implementing the present invention may be other structures or the like as long as the object of the present invention can be achieved. [Explanation of symbols]

[0032] 1 Machine tools 3 Flanged grinding wheels 4. Whetstone 5 Fixed flange (flange) 6 Nut (flange) 8 Balance Piece 10 Balancing tool 11 Foundation 12 Support pillar 13 Arbor 14 Bearings 15 Marker holder 121 Load support section

Claims

1. A grinding wheel balancing tool for adjusting the balance of a flanged grinding wheel, the flange comprising a grinding wheel and a pair of flanges that sandwich the grinding wheel and have a spindle insertion hole formed at the center of rotation into which a spindle of a machine tool is inserted, The base and a pair of support columns extending vertically upward from the surface of the base and having load support portions formed at their tips; an arbor inserted into the spindle insertion hole; a pair of bearings provided at both ends of the arbor, supported by the load support portion, and rotatably holding the flanged grinding wheel; A tool for adjusting the balance of grinding wheels.

2. a marker holder provided along the extending direction of at least one of the pair of support columns, for marking an imbalance point of the flanged grinding stone on at least one side surface of the grinding stone and the flange; The grindstone balancing tool according to claim 1.

3. A method for adjusting the balance of a flanged grinding wheel, which includes a grinding wheel and a pair of flanges that sandwich the grinding wheel and have a spindle insertion hole formed at the center of rotation, into which a spindle of a machine tool is inserted, comprising: inserting an arbor into the spindle insertion hole; mounting a bearing on each end of the arbor; supporting each of the bearings on a horizontal surface and oscillating the flanged grinding wheel; and marking an imbalance point of the flanged grindstone on at least one side surface of the grindstone and the flange after the swinging of the flanged grindstone has stopped. How to balance a grinding wheel.

4. a step of attaching a first balance piece to a side surface of the flange that becomes an unbalance point of the flanged grinding wheel; attaching a second balance piece to a side surface of the flange different from the attachment position of the first balance piece; and repeating the swinging of the flanged grinding stone and adjusting the position of the attached second balance piece until the flanged grinding stone starts to roll without stopping the swinging.

4. The method for adjusting the balance of a grinding wheel according to claim 3.

5. a step of marking the spindle of the machine tool in accordance with the marking position of the flanged grinding wheel, 5. The method for adjusting the balance of a grinding wheel according to claim 3 or 4.

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