Automatic grinding machine

Abstract

In conventional grinding using horizontal-axis rotating grinding wheels, there was a problem in grinding workpieces with stepped shapes where the grinding wheel interfered with other parts, making it difficult to grind the outer surface and top surface. [Solution] The present invention provides an automatic grinding device that can efficiently grind the outer and upper surfaces of stepped workpieces by employing a vertical axis rotating grinding wheel. Furthermore, the grinding program can accommodate various products by specifying the target position of operation, and since this target position of operation is set by direct teaching or coordinate input by the on-site operator, there is no need to manually input detailed NC code as in the conventional method, and grinding control can be automatically performed on the part of the workpiece to be ground based on the input information of the on-site operator.

Description

Technical Field

[0001] The present invention relates to an automatic grinding device that automatically grinds a grinding target portion on a workpiece surface according to a program based on information (operation target position, grinding location, distance, etc.) input by an on-site operator, and a program thereof.

Background Art

[0002] In the manufacture of cast products, it is necessary to remove the riser portion generated during casting. Conventionally, for removing this riser portion, cutting and grinding by manual work have been performed, but it depends on the skill level of the operator, and there are problems with work efficiency and machining accuracy. For this reason, a grinding device for efficiently and stably removing the riser portion has been proposed. For example, a device that grinds the riser portion of a cast product using a rotary grinding wheel is known (see Patent Document 1, etc.).

[0003] Patent Document 1 is a "casting finishing device" whose configuration consists of a hydraulic servo grinding machine and a positioner that performs arithmetic control with a control device having a storage unit. The hydraulic servo grinding machine can move to an arbitrary position three-dimensionally, and at least the operation of the grinding wheel is performed hydraulically by controlling a servo valve and is installed on a gantry. The positioner includes a lifter that can move up and down, a rotating table that is rotatably provided on the lifter, a swing table that is swingably supported on the rotating table via a frame, and a rotating work table fixed to the longitudinal central axis of the swing table. The operations of the lifter, rotating table, swing table, and rotating work table can be reproduced based on a memory input in advance via a transducer. Regarding the grinding wheel of Patent Document 1, the rotation axis of the grinding wheel is horizontal, and the grinding wheel adopts a configuration that rotates in a vertical plane (see FIGS. 1 and 2).

[0004] The invention described in Patent Document 1 has many excellent effects, particularly when grinding casting burrs, excess material, etc., of large castings. It frees the operator from heavy labor and injuries caused by vibration by using a hydraulic servo grinding machine, and by reproducibly controlling a positioner with a novel structure using a microcomputer, it facilitates changing the posture of the rigid material, enabling efficient and safe grinding work.

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 152058 / 1983 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Product parts come in various shapes, but some have a stepped shape with a large diameter at the bottom and a small diameter at the top. In such workpieces, there are parts to be ground on the outer surface and top surface. The invention described in Patent Document 1 used a grinding wheel that rotated on a horizontal axis for grinding, but depending on the outer diameter of the grinding wheel, it could interfere with other parts, making grinding difficult. [Means for solving the problem]

[0007] Therefore, the present invention provides an automatic grinding device that employs a relatively wide grinding wheel that rotates in a horizontal plane, i.e., a vertical axis rotating grinding wheel, which enables efficient grinding of the upper outer surface and top surface of a workpiece with a stepped shape without the grinding wheel interfering with other parts. Furthermore, the present invention relates to an automatic grinding device and program that automatically grinds the part of the workpiece surface to be ground according to a program based on information (operation target position, grinding location and distance, etc.) input by an on-site operator.

[0008] The invention of claim 1 is an automatic grinding device for automatically grinding a portion of the surface of a workpiece, comprising: a rotary work table on which a workpiece is placed and which is rotatable; a grinding wheel which is rotatable in the horizontal direction; and Multiple grinding motion patternsThe control device comprises a storage unit that stores a number of grinding programs and a teaching unit that receives input for the target operating positions of the grinding wheel and the rotating work table, and the grinding program The target position of the internal movement can be switched for each workpiece by specifying numerical values ​​from the teaching unit. Because the program is completed simply by inputting dedicated numerical values ​​for each target workpiece, the user does not need to write the operation program using a programming language. By switching these specified numerical values... It is designed to be compatible with a wide variety of products. That specified value This is specified by direct teaching, which is performed by on-site workers directly moving the grinding wheel vertically and / or the rotating work table horizontally, or by directly inputting coordinates. In this way This automatic grinding device automatically grinds the target area of ​​a workpiece surface by moving the grinding wheel vertically and / or the rotating worktable horizontally according to a grinding program based on a specified target position.

[0009] The invention of claim 2 is an automatic grinding device according to claim 1, characterized in that the width of the grinding wheel is 35 mm to 55 mm, and the shaft output of the grinding wheel rotation shaft that rotates the grinding wheel is 3.5 kW to 11 kW.

[0010] The invention of claim 3 is an automatic grinding apparatus according to claim 1 or claim 2, characterized in that the shape of the workpiece is mainly cylindrical, disc-shaped, or similar.

[0011] The invention of claim 4 is a rotary worktable is, The automatic grinding apparatus according to claim 1 or claim 2, characterized by having a scroll chuck with a number of chuck jaws.

[0012] The invention of claim 5 is a rotary worktable is, The automatic grinding apparatus according to claim 3, characterized by having a scroll chuck with a number of chuck jaws.

[0013] The invention of claim 6 is a program for controlling an automatic grinding apparatus according to claim 1 or claim 2, comprising a product number input reception step for receiving input of a product number to a control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step in which the grinding program corresponding to the desired grinding area is selected according to the operation of the on-site worker. A motion target position teaching and specification step that accepts target coordinates and angles by direct teaching or direct input and teaches and specifies the motion target position, A rotary worktable operation setting step that sets the forward distance and rotation speed of the rotary worktable according to the operation of the on-site worker. This program is characterized by executing a start command reception step that receives a start command in response to an operation by a field worker.

[0014] The invention of claim 7 is a program for controlling the automatic grinding apparatus described in claim 3, A product number input acceptance step that accepts the input of a product number to the control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step in which the grinding program corresponding to the desired grinding area is selected according to the operation of the on-site worker. A motion target position teaching and specification step that accepts target coordinates and angles by direct teaching or direct input and teaches and specifies the motion target position, A rotary table operation setting step that sets the forward distance and rotational speed of the rotary work table according to the operation of the on-site worker. This program is characterized by executing a start command reception step that receives a start command in response to an operation by a field worker.

[0015] The invention of claim 8 is a program for controlling the automatic grinding apparatus described in claim 4, A product number input acceptance step that accepts the input of a product number to the control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step of selecting a grinding program corresponding to a desired grinding location according to the operation of an on-site operator; An operation target position teaching and specifying step of receiving target coordinates and an angle by direct teaching or direct input and teaching and specifying an operation target position; A rotating table operation setting step of setting the forward movement amount and rotation speed of a rotating work table according to the operation of an on-site operator; A program characterized by executing a start command receiving step of receiving a start command according to the operation of an on-site operator.

[0016] The invention of claim 9 is a program for controlling the automatic grinding device according to claim 5, A product number input receiving step of receiving an input of a product number by a control device; A product number confirmation step of confirming the input of the product number; A program registration screen display step of displaying a program registration screen; A grinding program selection step of selecting a grinding program corresponding to a desired grinding location according to the operation of an on-site operator; An operation target position teaching and specifying step of receiving target coordinates and an angle by direct teaching or direct input and teaching and specifying an operation target position; A rotating table operation setting step of setting the forward movement amount and rotation speed of a rotating work table according to the operation of an on-site operator; A program characterized by executing a start command receiving step of receiving a start command according to the operation of an on-site operator.

Advantages of the Invention

[0017] According to the present invention, the grinding cycle time can be shortened by reducing the number of times the grinding wheel makes contact with the workpiece due to the relatively wide grinding wheel, and stable grinding can be achieved even on workpieces with stepped shapes or complex shapes by the grinding wheel rotating in a horizontal plane. Furthermore, since the program is completed by specifying only the target coordinates in a pre-prepared grinding program, it can be easily programmed even by those without special training. [Brief explanation of the drawing]

[0018] [Figure 1] This is a side view of an automatic grinding machine. [Figure 2] This is a plan view of an automatic grinding machine. [Figure 3] This diagram illustrates an automatic grinding machine; (a) is a front view of the automatic grinding machine, and (b) is a block diagram of the control device. [Figure 4] This is a front view photograph of the main part of an automatic grinding machine. [Figure 5] The side view shows the relationship between the workpiece and the grinding wheel. (a) shows the state in which a grinding wheel rotating in a vertical plane, i.e., a horizontal axis rotating grinding wheel, is used to grind the lower and upper outer surfaces of a workpiece with a stepped shape. (b) shows the state in which a grinding wheel rotating in a horizontal plane, i.e., a vertical axis rotating grinding wheel (a grinding wheel fixed perpendicularly to a vertical grinding wheel rotation axis), is used to grind the lower and upper outer surfaces of a workpiece with a stepped shape. [Figure 6] This is a perspective view of a rotary worktable. [Figure 7] This is a perspective view of a rotary worktable equipped with an annular ring. [Figure 8] This is a perspective view showing the state during direct teaching. [Figure 9] This is the product selection screen on the control panel's monitor. [Figure 10] This is the program registration and target position input screen on the control panel's monitor. [Figure 11] This is the screen for specifying the forward movement and rotation speed of the rotary worktable. [Figure 12]This is a flowchart of the operation method and program for an automatic grinding apparatus according to the present invention. (a) is a flowchart showing the operation method by an on-site worker, and (b) is a flowchart showing the processing procedure of a program executed by a control device. [Figure 13] In the diagram of the workpiece before grinding, (a) shows the state where the "gutter" and "plate weir" are located on different levels, and (b) shows the state where the "gutter" and "plate weir" are aligned on the same level. [Figure 14] This is a perspective view of the workpiece before grinding, showing the formation of minute gas venting marks on the product surface. [Figure 15] In the diagram of the grinding process, (a) is a perspective view just before grinding, (b) is a perspective view of the outer circumference being ground, and (c) is a perspective view of the sprue being ground. [Modes for carrying out the invention]

[0019] As shown in Figure 1, the automatic grinding apparatus 1 of the present invention comprises a grinding wheel 30 fixed to a grinding wheel spindle 35 driven by a grinding wheel rotation motor 33, a rotating work table 10 on which a workpiece wK is placed, supports and rotates, and a control device 50 that specifies an operation target position based on the relative position between the grinding wheel 30 and the workpiece wK, and controls the grinding operation of the workpiece wK according to a pre-stored processing program based on the acquired operation target position data. The automatic grinding apparatus 1 is mainly used to automatically grind the grinding target portion TG (unnecessary portion) of the surface SF (outer surface, top surface, etc.) of a workpiece wK (casting such as ductile cast iron) that is cylindrical or disc-shaped, and is used in casting finishing, grinding processes, etc. The control device 50 (computer) provided in the present invention has a storage unit 50a, a teaching unit 50b, a calculation unit 50c, and a control unit 50d (see Figure 3(b)). The program of the present invention is mainly processed by the calculation unit 50c in the control device 50. The control unit 50d decodes the product number and grinding program stored in the memory unit 50a and instructs the calculation unit 50c to process. The calculation unit 50c receives coordinate and angle information input from the teaching unit 50b and sequentially executes each step based on the grinding program.

[0020] In the automatic grinding apparatus 1, the grinding wheel 30 is driven to rotate by a grinding wheel rotation motor 33 (servo motor) and performs grinding operations at a predetermined rotational speed. The grinding wheel 30 used to grind the target area TG of the surface SF of the workpiece wK is appropriately selected based on the material and grit size of the target area TG. For example, a carbide grinding wheel, specifically a diamond grinding wheel made of many diamond particles bound together with a binder, is used.

[0021] The grinding wheel 30 is formed in an annular (donut-shaped) form by drilling a through hole 32 in the center of its flat surface, and the tooth width Bw of the grinding wheel 30 is 35 mm to 55 mm, with a particularly preferable width of 48 mm to 50 mm.

[0022] The grinding wheel 30 is driven to rotate by a grinding wheel rotation motor 33, the shaft output of which is in the range of 3.5 kW to 11 kW. Particularly desirable is the use of a grinding wheel rotation motor 33 with an output of 7.5 kW, which optimizes grinding performance and energy efficiency.

[0023] In typical manual grinders (hand-operated grinders) where the operator holds the grinding wheel by hand, a tooth width Bw of approximately 50 mm is commonly used for the grinding wheel 30. In contrast, well-known automatic grinding devices (mechanical grinding) employ grinding wheels 30 with relatively thin tooth widths Bw of approximately 10-14 mm to accommodate complex shapes and diverse products. Each has its advantages and disadvantages, but the tooth width Bw of the grinding wheel 30 is an important factor that affects the grinding time. In the automatic grinding device 1 of the present invention, increasing the tooth width Bw of the grinding wheel reduces the number of times the grinding wheel 30 is applied, thereby shortening the grinding cycle time. On the other hand, the increase in weight of the grinding wheel due to the increased tooth width Bw is addressed by employing a high-capacity motor.

[0024] In this way, by employing a high-capacity motor (grinding wheel rotation motor 33) to rotate a relatively wide grinding wheel 30, the grinding cycle time can be shortened. Specifically, the grinding time was reduced to about 1 / 2 to 1 / 3 compared to manual grinding (our company's comparison).

[0025] The relationship between the grinding wheel 30 and the grinding wheel 33, that is, the arrangement and rotational drive of the grinding wheel 30, will be explained. The motor shaft 33b of the grinding wheel rotating motor 33 extends from the motor body 33a in the axial direction AX (vertical direction VD), and this motor shaft 33b is configured to transmit rotational force to the grinding wheel spindle 35, which is erected in the axial direction AX (vertical direction VD), via a belt drive system or a gear drive system. The grinding wheel 30 is fixed horizontally (perpendicularly) to the grinding wheel spindle 35 and is rotatable in the horizontal direction HD (perpendicular direction). That is, by inserting the through hole 32 of the grinding wheel 30 into the grinding wheel spindle 35 in the vertical direction VD, the grinding wheel 30 is fixed in a direction perpendicular to the grinding wheel spindle 35 (vertical direction VD) (horizontal direction HD). The grinding wheel 30 according to the present invention rotates around a grinding wheel spindle (vertical axis) in the vertical direction VD, and its grinding surface (grinding surface) 31 is arranged parallel to the horizontal plane, thus enabling rotation in the horizontal direction HD. The rotational drive of the grinding wheel 30 can be selected from a belt drive system or a gear drive system depending on the design conditions, but other drive methods may also be used.

[0026] Various shapes can be assumed for the workpiece wK (product part), as illustrated in Figures 5, 13, and 14, etc., but for example, there is a stepped shape where the lower part is large in diameter and the upper part is small in diameter, that is, a stepped shape in which the outer circumference is divided into two stages. In a workpiece wK having such a stepped shape, there may be grinding targets TG on the upper outer surface, the lower outer surface, and the top surface.

[0027] Conventionally, when grinding the lower and upper outer surfaces of a workpiece wK having a stepped shape using a grinding wheel 30 that rotates in a vertical plane, i.e., a horizontal axis rotating grinding wheel 30, depending on the outer diameter of the grinding wheel 30, there was a risk that the grinding wheel would interfere with other parts when grinding the upper outer surface or top surface, making grinding difficult (see "×" in Figure 5(a)).

[0028] In the configuration according to the present invention, by employing a grinding wheel 30 that rotates in a horizontal plane, that is, a vertical axis rotating grinding wheel 30 (a grinding wheel 30 fixed perpendicularly to a vertical grinding wheel spindle 35), it becomes possible to efficiently grind the upper outer surface, lower outer surface, and top surface of a workpiece wK having a stepped shape without the grinding wheel 30 interfering with other parts (see "〇" in Figure 5(b)). As a result, stable grinding is achieved even for workpieces wK having stepped shapes or complex shapes.

[0029] In this invention, the grinding wheel 30 moves up and down as the grinding wheel unit 300 moves up and down. The grinding wheel unit 300 consists of the grinding wheel rotation motor 33, the grinding wheel spindle 35, the grinding wheel 30, and the base 40 that integrally supports these components, as described above.

[0030] In this manner, the grinding wheel unit 300, including the grinding wheel 30, is moved up and down to accommodate the part TG (unnecessary part) of the surface SF of the workpiece wK. This up and down movement is performed by a grinding wheel unit 300 up and down feeding mechanism consisting of a linear motion guide mechanism 42 (lifting LM guide mechanism) and a ball screw mechanism 47.

[0031] The linear guide mechanism 42 is a mechanism for moving the grinding wheel unit 300 up and down in the vertical direction VD along a pair of guide rails 44 on the base 40. Using this linear guide mechanism 42, a ball screw mechanism 47 is arranged, which consists of a lifting ball screw 45 (male screw rod) erected in the vertical direction VD, a lifting motor 46 (servo motor) that rotates the lifting ball screw 45, and a connecting part (not shown) with a through-hole female screw fixed to the base 40. This enables the grinding wheel unit 300 to move up and down. The specific arrangement configuration is as follows.

[0032] As illustrated in Figure 1, the rotating shaft 46b of the lifting motor 46 that constitutes the ball screw mechanism 47 extends from the motor body 46a in the axial direction AX (horizontal direction HD), and this rotating shaft 46b is configured to transmit rotational force to the lifting ball screw 45 via a belt drive or gear drive. A connecting part is fixed to the back of the base 40 that constitutes the grinding wheel unit 300, protruding rearward from the center in the width direction, and a through female screw hole is screwed into this connecting part in the vertical direction, and the lifting ball screw 45 is screwed into this female screw hole. With the grinding wheel unit up and down feeding mechanism consisting of the ball screw mechanism 47 configured in this way, when the lifting motor 46 rotates forward, the grinding wheel unit 300, i.e. the grinding wheel 30, descends, and when the lifting motor 46 rotates in reverse, the grinding wheel unit 300, i.e. the grinding wheel 30, ascends. The relationship between the lifting motor 46 and the lifting ball screw 45 is selected according to the design conditions, whether it is a belt drive system or a gear drive system, but other drive methods may also be used.

[0033] The rotary worktable 10 is designed to hold and rotate the workpiece wK. Specifically, the rotary worktable 10 holds and rotates the workpiece wK around its axis, thereby enabling automatic grinding of the grinding target portion TG (unnecessary portion) of the surface SF of the workpiece wK while the workpiece wK is rotating.

[0034] The rotary worktable 10 is equipped with a scroll chuck, and in some cases, a support jig is used to hold the workpiece wK. The scroll chuck is equipped with multiple (3 or 4) chuck jaws 13, and the scroll mechanism allows multiple jaws to move simultaneously inward (IN) or outward (OUT), enabling the workpiece wK to be held evenly around the center (see Figure 6). It is particularly suitable for holding cylindrical or disc-shaped workpieces wK, and the workpiece wK can be set up quickly. The jaws may be machined to match the shape of the workpiece wK. In the case where the workpiece wK is held using only the scroll chuck without a support jig, the workpiece receiving surface of the chuck jaws 13 can also be used as the receiving part of the workpiece wK. In this case, since the workpiece receiving surface is in direct contact with the workpiece wK, hardening, hard coating, etc. may be applied to suppress wear.

[0035] Although not shown in the diagram, a scroll plate that rotates via a handle (key) is housed inside the rotary worktable 10. The scroll plate has a helical groove (cam groove) engraved on it, and each chuck jaw 13 has a pin on its back side that engages with this groove. When the handle (key) in the center of the chuck body is turned, the scroll plate rotates, and this rotation causes each jaw to simultaneously advance towards the center or retract outwards.

[0036] The scroll chuck has an integrated chuck jaw 13 which consists of an "outer chuck jaw" that grips the outer diameter side of the workpiece wK as shown in Figure 1, and an "inner chuck jaw" that chucks the workpiece wK from the inside IN. By changing the orientation of the jaws, it is possible to grip both the outer and inner diameters.

[0037] As a support fixture for the workpiece wK, an annular ring 15 (see Figure 7) that supports the workpiece wK from below, or a columnar member that supports the workpiece wK from below may be provided. When an annular ring 15, which is an example of a support fixture, is provided on the rotary worktable 10, a crank-shaped support member is erected and fixed to the surface between a plurality of chuck jaws 13 arranged at equal intervals on the circumference via fasteners such as bolts, and the annular ring 15 is fixed above the support member with fasteners such as bolts. In this way, the annular ring 15 supported by the support member is fixed on the rotary worktable 10.

[0038] The rotary worktable 10 according to the present invention has a configuration that allows the rotary worktable 10 holding the workpiece wK to rotate and move in the horizontal direction HD (front-rear direction relative to the grinding wheel 30), and is composed of the following mechanism.

[0039] The rotation of the rotary worktable 10 is performed by either an outer periphery contact method using a drive wheel 20 (see Figure 2) or a direct connection method to the central axis using a rotary motor (not shown).

[0040] The outer periphery contact method comprises a rotating worktable 10 and a drive wheel 20 that contacts the rotating worktable 10 to transmit rotational force. The drive wheel 20 is driven by a worktable rotation motor 22 and applies rotational force to the outer periphery or lower surface of the rotating worktable 10 through frictional contact or gear meshing.

[0041] The direct-drive system is achieved by a rotary motor (servo motor) located beneath the table. The rotation axis of this rotary motor is directly connected to the central axis of the rotary worktable 10, or connected via a reduction gear, thereby achieving stable rotational operation.

[0042] In this invention, the table unit 100 moves back and forth, causing the workpiece wK supported on the rotary worktable 10 to also move back and forth. The table unit 100 consists of the rotary worktable 10, the worktable rotation motor 22, and the base 28 that integrally supports them, as described above. If the rotation of the rotary worktable 10 is by an outer peripheral contact method, it also includes a drive wheel 20, etc.

[0043] The table unit 100, including the rotary worktable 10, is moved back and forth relative to the grinding wheel 30 to automatically grind the part TG (unnecessary part) of the surface SF of the workpiece wK supported on the rotary worktable 10. The means for moving the table unit 100 back and forth is a rotary worktable forward and backward feed mechanism consisting of a linear guide mechanism 23 (forward and backward LM guide mechanism) and a ball screw mechanism 27.

[0044] The linear motion guide mechanism 23 is a mechanism for moving the table unit 100 along a pair of guide rails 24, with the base 28 moving back and forth. Using this linear motion guide mechanism 23, a ball screw mechanism 27 is positioned below the table unit 100, consisting of a ball screw 25 (male screw rod) for forward and backward movement extending in the horizontal direction HD (X-axis direction X), a motor 26 (servo motor) for forward and backward movement that rotates the ball screw 25, and a connecting part (not shown) with a through-hole female screw fixed to the base 28. This enables the forward and backward movement of the table unit 100. The specific arrangement configuration is as follows.

[0045] The ball screw mechanism 27 comprises a forward / reverse motor 26, a forward / reverse ball screw 25 that is interlocked with the forward / reverse motor 26, and a connecting part (female thread member) that is screwed into the forward / reverse ball screw 25. As shown in Figure 2, the rotating shaft 26b of the forward / reverse motor extends horizontally HD (Y-axis direction Y) from the motor body 26a, and this rotating shaft 26b is configured to transmit rotational force to the forward / reverse ball screw 25 via a belt drive or gear drive. A connecting part is fixed to the back of the base 28 that constitutes the table unit 100, protruding rearward from its widthwise center, and a through female thread hole is screwed into this connecting part in the vertical direction, into which the forward / reverse ball screw 25 is screwed. In this way, the table unit forward and backward feeding mechanism consisting of the ball screw mechanism 27 moves the table unit 100, i.e., the workpiece wK, forward when the forward and backward motor 26 is rotated forward, and moves the table unit 100, i.e., the workpiece wK, backward when the forward and backward motor 26 is rotated in the reverse direction. The relationship between the forward and backward motor 26 and the forward and backward ball screw 25 can be selected according to the design conditions, whether it is a belt drive system or a gear drive system, but other drive methods may also be used.

[0046] The rotary worktable 10 can be configured to move not only in the horizontal direction HD (X-axis direction X), but also in the left-right direction (Y-axis direction Y), although this is not shown in the diagram. In this case, a cross-table mechanism (not shown) consisting of a Y-axis table and an X-axis table may be used.

[0047] The Y-axis table is movable in the left-right direction in the horizontal plane. The X-axis table is positioned on the Y-axis table and is movable horizontally (HD). Movement in each axis is performed via a corresponding ball screw mechanism and is precisely controlled by a cross-table drive motor.

[0048] A male threaded rod extending in the left-right direction is positioned beneath the rotating worktable 10. The male threaded rod is rotatably supported by bearing members on the right and left sides, and a servo motor (drive source) is installed on the right side. A connecting part having a female threaded hole that penetrates in the left-right direction is fixed to the back of the rotating worktable 10, and functions as a ball screw mechanism when screwed into the male threaded rod. The rotation of the servo motor causes the rotating worktable 10 to move in the left-right direction.

[0049] In the X-axis direction, two linear guide rails are arranged parallel to each other, and a sliding table (moving stage) is placed on top of them. A ball screw is placed in the center and driven by a motor. The rotary worktable 10 is fixed to this sliding table.

[0050] Regarding the Y-axis direction, a linear guide and ball screw for the Y-axis are placed below the X-axis stage. As the Y-axis stage moves left and right, and the X-axis stage is placed on top of it, the rotary worktable 10 can move freely in the XY direction.

[0051] Thus, the rotary worktable 10 of the present invention, by combining a rotation mechanism with a rotary worktable forward / backward feeding mechanism or a cross table mechanism, enables rotation and high-precision positioning of the workpiece wK, providing a structure suitable for grinding and precise position adjustment.

[0052] As described above, the present invention is an automatic grinding device 1 used in casting finishing, grinding processes, etc., and mainly automatically grinds the grinding target portion TG (unnecessary portion) of the surface SF of the workpiece wK. Castings and cast iron products (workpiece wK) are often truck undercarriage parts, construction machinery reducer parts, and robot reducer parts, and are often cylindrical or disc-shaped. The scroll chuck that holds this workpiece wK has a structure in which multiple chuck jaws 13 move simultaneously by the rotation of the scroll plate, and each jaw moves inward (IN) or outward (OUT) at a constant speed, so that it makes even contact with the outer diameter of the workpiece wK and is naturally centered. Workpieces wK, such as cylindrical or disc-shaped ones, have a uniform outer diameter, and the center is determined by clamping them evenly at 3 or 4 points. Therefore, eccentricity is less likely to occur, and the center of rotation and the center of the workpiece wK tend to coincide. For these reasons, cylindrical or disc-shaped "round objects" can be held stably and ground with high precision by a scroll chuck, making them particularly suitable for grinding processes. Therefore, the present invention is suitable for round objects (see Figure 13, etc.). There are no particular restrictions on the weight of the workpiece wK, and heavy objects weighing 400-500 kg can also be used.

[0053] As is well known, castings and cast iron are manufactured by melting iron at high temperatures to make it liquid, pouring it into a mold, and allowing it to cool and solidify. However, shrinkage occurs during the solidification process from liquid to solid. In the casting process, risers are formed in the mold to compensate for the volume reduction caused by solidification shrinkage in the product (workpiece wK). These risers function as excess material, supplying liquid metal to the product and preventing casting defects such as shrinkage cavities from occurring in the product during the solidification process. This ensures that no shrinkage remains in the product, thus guaranteeing the desired quality. Riveters are generally cylindrical in shape, where the modulus (volume of the casting divided by the cooling surface area) is larger than that of the product, and the cooling rate is slower. They maintain a liquid state even after the product has finished solidifying, supplying the metal to compensate for the shrinkage.

[0054] After casting, the riser portion, which is excess material attached to the product, must be removed. The joint between the riser portion and the product is called a "gutter" or "sprung," and because this gutter has a relatively large volume, it must be completely removed in the finishing process. After the removal of the riser portion, residue of the unwanted material (grinding target area TG) remains on the product, so finishing is required to grind it off (see Figure 13). In addition, the use of a venting rod creates minute venting marks on the surface SF (see Figure 14), and such venting marks (grinding target area TG) must be removed or finished in a later process.

[0055] In casting structures, in addition to the riser, a plate weir can be provided as a gate to introduce molten metal into the product while controlling the flow of the molten metal. Therefore, due to constraints such as the shape of the product, there are products in which the "sprue" and the "plate weir" are located on different height levels (see Figure 13(a)) and products in which the "sprue" and the "plate weir" are located on the same level (see Figure 13(b)).

[0056] When removing the sprue is done manually using a grinder or similar tool, the cutting load is high because the area in question is a hardened metal mass, placing a heavy burden on the operator. Even when using an automatic finishing machine, the motor load increases sharply when cutting the sprue, so it is necessary to control the processing speed of the area and cut it at a lower speed than other areas. For this reason, the feed rate of the grinding head, i.e., the pressing speed and positional movement speed of the workpiece wK, are controlled to be reduced. Typically, one or more sprues are provided for a single casting product, so the sprue removal process is a major source of load in the finishing process of the casting. Therefore, appropriate control of the grinding speed is essential. This appropriate control of the grinding speed, such as by a grinding program, is performed by the control device 50 of the present invention.

[0057] The grinding program stored in the control device 50 of the present invention is designed to accommodate various products (workpieces wK) by allowing the on-site worker wR to specify the target position of movement. This target position of movement is specified by direct teaching, which is performed by the on-site worker wR directly moving the grinding wheel 30 (grinding wheel unit 300) in the vertical direction VD and / or the rotary worktable 10 (table unit 100) in the horizontal direction HD, or by directly inputting coordinates. Based on the target position of movement specified and taught through direct teaching or direct input of coordinates, the grinding wheel 30 and / or the rotary worktable 10 (workpiece wK) move according to the grinding program and automatically grind the target portion TG on the surface of the workpiece wK.

[0058] The grinding program is stored in the memory unit 50a of the control device 50, and grinding is performed according to the program in the memory unit 50a based on the information (operation target position, grinding location and distance, etc.) input to the teaching unit 50b. In other words, the grinding program is automatically generated when the on-site worker wR inputs the amount of grinding by contacting the workpiece wK with the grinding wheel 30 and storing the position, eliminating the need to manually input detailed NC code as in the past.

[0059] The control device 50 acquires data (target position of operation) necessary for machining the workpiece wK through direct teaching or direct input of coordinates by the on-site worker wR. Furthermore, based on the acquired data, it controls the grinding wheel rotation motor 33, the work table rotation motor 22, the forward and backward movement motor 26 of the forward and backward movement mechanism of the rotary work table, the lifting motor 46 of the up and down movement mechanism of the grinding wheel unit, and other motors such as the cross table drive motor if necessary, according to a pre-stored grinding program. The operation method of the program of the automatic grinding device 1 by the on-site worker wR will be explained below in accordance with the flowchart in Figure 12(a).

[0060] First, the product number is entered (product number input step ST1) from the product selection screen (see Figure 9) on the monitor screen 58 of the control panel 55. After entering the product number using alphanumeric characters, the next step is to press the product number button (product number confirmation step ST2), which displays the program registration screen (see Figure 10) (program registration screen display step ST3).

[0061] In the step of entering the program registration screen (program registration screen display step ST3), the user selects either grinding program A or grinding program B on the program registration screen shown in Figure 10, according to the desired grinding area (grinding program selection step ST4).

[0062] Regarding the program, two types of programs, grinding program A (outer circumference) and grinding program B (gutter), are pre-stored and registered in the memory unit 50a. Grinding program A is an outer circumference grinding mode program that grinds one full turn, but allows setting sections in which the workpiece wK rotation speed is reduced. Grinding program B is a gutter grinding mode program that grinds only the specified section at the specified workpiece wK rotation speed.

[0063] On the screen, there are grinding patterns for process 1 (outer circumference), process 2 (grunge), process 3 (outer circumference), process 4 (grunge), process 5 (outer circumference), and process 6 (grunge). Processes 1 (outer circumference), 3 (outer circumference), and 5 (outer circumference) are grinding program A, and processes 2 (grunge), 4 (grunge), and 6 (grunge) are grinding program B (see Figure 10). As described above, both grinding program A and grinding program B can each register 3 processes, for a total of 6 processes.

[0064] The type shown in Figure 13(a) is an outer circumference grinding mode (grinding program A, reduced speed) in which only the "gutter" portion is ground at a reduced speed. The product of type 13(b) is a mode in which only the "gutter" portion is ground in gutter grinding mode (grinding program B, specified rotation speed), and the plate weir portion is ground in outer circumference grinding mode (grinding program A, reduced speed). In this case, the outer circumference grinding setting involves slightly reducing the speed for the plate weir portion.

[0065] The target coordinates and angle are directly taught or directly input (motion target position teaching specification step ST5). In this direct teaching or direct input of coordinates by the field worker wR, the motion target position is specified based on the relative position between the workpiece wK and the grinding wheel 30. Then, the grinding operation of the workpiece wK is controlled according to this motion target position.

[0066] The actual direct teaching procedure is as follows: Primarily, a teaching function is used to store information in the teaching unit 50b of the control device 50. The field operator wR manually brings the workpiece wK close to the grinding wheel 30 and stores the contact point. Specifically, in order to grind the grinding target area TG on the outer surface of the workpiece wK with high precision, two points—the lowest point on the outer surface of the workpiece wK and the highest point on the grinding target area TG—are measured using direct teaching or direct coordinate input, and the height difference between these two points is stored. As a result, the feed rate of the grinding wheel 30 is controlled based on the height difference, and the grinding wheel 30 can be automatically moved to a predetermined depth relative to the grinding target area TG. This enables high-precision grinding that can accommodate individual differences in the workpiece wK and changes in the shape of the grinding target area TG.

[0067] The coordinates stored in this teaching unit 50b can be reflected in the NC program. That is, these coordinates are used as a reference point and reflected in the grinding program. Correction values ​​(offsets) are also set as needed.

[0068] On the screen shown in Figure 11, the forward movement and rotation speed of the rotary worktable 10 are specified (rotary worktable operation setting step ST6). Then, grinding is started by pressing the start button (start button press step ST7). As shown in Figure 15, the workpiece wK and grinding wheel 30 rotate in the direction of the arrow, grinding the target part TG.

[0069] In the automatic grinding apparatus 1 of the present invention, by going through the above process, it is not necessary to manually input detailed NC code by a programmer with specialized knowledge as in the conventional method. Instead, the on-site operator wR can directly move the grinding wheel in the vertical direction VD and / or the table unit 100 in the forward, backward, left, and right directions, thereby performing direct teaching or directly inputting coordinates. Based on the information specified and input (such as the target position of movement, grinding location and distance), the grinding target portion TG of the workpiece wK surface can be automatically ground according to the program.

[0070] Next, the program for controlling the automatic grinding apparatus 1 of the present invention will be described. First, a product number input acceptance step ST11 is performed to receive a product number input into the control device 50, then a product number confirmation step ST12 is performed to confirm the input of the product number, then a program registration screen display step ST13 is performed to display the program registration screen, then a grinding program selection step ST14 is performed to select a grinding program corresponding to the desired grinding location, an operation target position teaching and specification step ST15 is performed to teach and specify the operation target position by receiving the target coordinates and angle by direct teaching or direct input, a rotary work table operation setting step ST16 is performed to set the amount of forward movement and rotational speed of the rotary work table 10, and finally a start command acceptance step ST17 is performed to receive a start command.

[0071] In the product number input acceptance step ST11, when the field worker wR inputs the product number using the monitor screen 58 of the control panel 55, the control device 50 accepts the input and stores it in its internal memory. This process prepares the device to identify the workpiece wK to be ground.

[0072] In the product number confirmation step ST2, once the entered product number is confirmed, the control device 50 confirms the number and makes it available for subsequent processing. This enables the selection of a grinding program based on the product information.

[0073] In step ST3, the program registration screen display, the control device 50 displays the program registration screen shown in Figure 10, allowing the field worker wR to select a grinding program. Multiple grinding programs are listed on this screen, and the field worker wR can select the grinding program corresponding to the desired grinding area.

[0074] In grinding program selection step ST4, the field worker wR selects either grinding program A or B, which corresponds to the desired grinding location, on the displayed program registration screen. The control device 50 accepts this selection and reflects it in the subsequent setting of the target position of the operation.

[0075] In step ST5, the operation target position teaching and specification, the field worker wR inputs the target coordinates and angle via direct teaching or direct input. The control device 50 receives these teaching inputs and teaches and specifies the operation target position. This process ensures that the grinding wheel 30 and the like are positioned accurately.

[0076] In the rotary worktable operation setting step ST6, the forward movement and rotational speed of the rotary worktable 10 are set according to the operation of the on-site worker wR. The control device 50 receives these settings and determines the operating conditions of the rotary worktable 10 necessary for the grinding operation. This makes it possible to align the workpiece and control the grinding speed.

[0077] In the start command reception step ST7, when the field worker wR presses the start button, the control device 50 receives the command and starts the grinding operation. This starts the grinding based on the set conditions.

[0078] By equipping the system with a laser sensor 60 for measuring product dimensions, highly reproducible grinding operations become possible. Since the dimensions and shape of workpieces wK, such as castings, can vary slightly from one piece to another, measuring the dimensions and position of the workpiece wK with the laser sensor allows for verification and correction of whether the position directly taught by the on-site worker wR is correct. Therefore, quantifying the dimensions and position of the workpiece wK with the laser sensor enables highly reproducible grinding operations.

[0079] The grinding wheel 30 is brought close to the workpiece wK, and the distance is measured using the laser sensor 60 for measuring product dimensions. The distance just before contact is memorized (e.g., 0.01 mm). This coordinate is registered as a teaching point. It can also be used for correction by re-measuring after machining.

[0080] The grinding apparatus according to the present invention may include a grinding powder receiving box 70 for collecting grinding powder generated during grinding. The grinding powder receiving box 70 is configured to efficiently collect fine metal particles generated during the grinding process, thereby preventing these metal particles from entering the machine and contributing to the suppression of wear and failure of machine parts. Furthermore, by suppressing the inhalation and scattering of grinding powder, it is possible to prevent health damage to the respiratory system of workers. In addition, by accumulating the grinding powder at a predetermined collection point, the efficiency of waste disposal and recycling can be improved.

[0081] The present invention has been described above based on the embodiments described above, but the present invention is not limited to the embodiments described above, and modifications may be made without departing from the spirit of the invention, or the techniques described in each embodiment or other known or well-known techniques may be combined. [Explanation of symbols]

[0082] 1: Automatic grinding machine 10: Rotating work table 13: Chuck jaws 15: Ring 20: Drive Wheel 22: Worktable Rotating Motor 23: Linear guide mechanism 24: Guide rail 25: Ball screw for forward and backward movement 26: Motor for forward and reverse movement 26a: Motor body 26b: Rotation axis 27: Ball screw mechanism 28: Bass 100: Table Unit 30: Sharpening stone 31: Sharpening stone surface 32: Through hole 33: Grinding wheel rotating motor 33a: Motor body 33b: Motor shaft 35: Grinding wheel spindle 40: Bass 42: Linear guide mechanism 44: Guide rail 45: Ball screw for lifting 46: Lifting motor 46a: Motor body 46b: Rotation axis 47: Ball screw mechanism 300: Grinding wheel unit 50: Control device 50a: Storage section 50b: Instruction Department 50c: Arithmetic section 50d: Control Unit 55: Control panel 58: Monitor screen 60: Laser sensor for measuring product dimensions 70: Grinding chip collection box Bw: tooth width AX: Axial direction VD: Vertical direction HD: Horizontal IN: Inside OUT: Outside wK: Work SF: Surface TG: Grinding target area wR: Field worker X:X-axis direction Y: Y axis ST1: Product Number Input Step ST2: Product Number Confirmation Step ST3: Program registration screen display step ST4: Grinding program selection step ST5: Step to specify the target position of the operation target ST6: Rotary worktable operation setting step ST7: Start button press step ST11: Product Number Input Acceptance Step ST12: Product Number Confirmation Step ST13: Program registration screen display step ST14: Grinding program selection step ST15: Step to specify the target position of the operation target ST16: Rotary worktable operation setting step ST17: Start command acceptance step

Claims

1. An automatic grinding device that automatically grinds the part of the workpiece surface to be ground, A rotary worktable on which the aforementioned workpiece is placed and which is rotatable, A grinding wheel that can rotate horizontally, The control device comprises a storage unit that stores multiple grinding programs with different grinding operation patterns in advance, and a teaching unit that receives input for the target operating positions of the grinding wheel and the rotating work table. The grinding program controls the grinding wheel or the rotating work table according to the grinding operation pattern defined by the grinding program, using the target operation position specified by the teaching unit as a reference point, thereby enabling it to handle a wide variety of products. The aforementioned target position of operation is specified by a numerical value obtained through direct teaching, performed by a field worker directly moving the grinding wheel in the vertical direction and / or the rotating work table in the horizontal direction, or by directly inputting coordinates. An automatic grinding device that, based on the specified target position of operation, moves the grinding wheel vertically and / or the rotating work table horizontally according to the grinding program, thereby automatically grinding the part of the work surface to be ground.

2. The automatic grinding apparatus according to claim 1, characterized in that the width of the grinding wheel is 35 mm to 55 mm, and the shaft output of the grinding wheel rotation shaft that rotates the grinding wheel is 3.5 kW to 11 kW.

3. The automatic grinding apparatus according to claim 1 or claim 2, characterized in that the shape of the workpiece is mainly cylindrical, disc-shaped, or similar.

4. The automatic grinding apparatus according to claim 1 or claim 2, characterized in that the rotary work table is equipped with a scroll chuck having a plurality of chuck jaws.

5. The automatic grinding apparatus according to claim 3, characterized in that the rotary worktable is equipped with a scroll chuck having a plurality of chuck jaws.

6. A program for controlling the automatic grinding apparatus according to claim 1 or claim 2, A product number input receiving step for receiving a product number from the control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step in which the grinding program corresponding to the desired grinding area is selected according to the operation of the on-site worker. A motion target position teaching and specification step that accepts target coordinates and angles by direct teaching or direct input and teaches and specifies the motion target position, A rotary worktable operation setting step in which the forward distance and rotational speed of the rotary worktable are set according to the operation of the on-site worker, A program characterized by executing a start command reception step that receives a start command in response to an operation by a field worker.

7. A program for controlling the automatic grinding apparatus described in claim 3, A product number input receiving step for receiving a product number from the control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step in which the grinding program corresponding to the desired grinding area is selected according to the operation of the on-site worker. A motion target position teaching and specification step that accepts target coordinates and angles by direct teaching or direct input and teaches and specifies the motion target position, A rotary table operation setting step in which the amount of forward movement and rotational speed of the rotary work table are set according to the operation of the on-site worker, A program characterized by executing a start command reception step that receives a start command in response to an operation by a field worker.

8. A program for controlling the automatic grinding apparatus described in claim 4, A product number input receiving step for receiving a product number from the control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step in which the grinding program corresponding to the desired grinding area is selected according to the operation of the on-site worker. A motion target position teaching and specification step that accepts target coordinates and angles by direct teaching or direct input and teaches and specifies the motion target position, A rotary table operation setting step in which the amount of forward movement and rotational speed of the rotary work table are set according to the operation of the on-site worker, A program characterized by executing a start command reception step that receives a start command in response to an operation by a field worker.

9. A program for controlling the automatic grinding apparatus described in claim 5, A product number input receiving step for receiving a product number from the control device, Product number confirmation step to confirm the input of the product number, Program registration screen display step, which displays the program registration screen. A grinding program selection step in which the grinding program corresponding to the desired grinding area is selected according to the operation of the on-site worker. A motion target position teaching and specification step that accepts target coordinates and angles by direct teaching or direct input and teaches and specifies the motion target position, A rotary table operation setting step in which the amount of forward movement and rotational speed of the rotary work table are set according to the operation of the on-site worker, A program characterized by executing a start command reception step that receives a start command in response to an operation by a field worker.

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