Grinding equipment

Abstract

To provide a grinding device comprising a valve which adjusts flow volume of grinding liquid according to grinding resistance.SOLUTION: A grinding device comprises: a workpiece support portion which supports a workpiece rotatably around an axis; a grindstone grinding the workpiece; a grinding resistance measurement device which measures grinding resistance occurring when the grindstone grinds the workpiece; a grinding liquid supply device which supplies grinding liquid to the vicinity of a grinding point where the grindstone grinds the workpiece; and a flow volume control unit which controls quantity of the grinding liquid supplied to the grinding point by the grinding liquid supply device. The grinding liquid supply device has: a flow passage portion where the grinding liquid flows; a cylinder portion connected to the flow passage portion; a piston-like valve element which can move to any position within a movable range from the cylinder portion to the inside of the flow passage portion; and a flow volume control motor which changes position of the valve element. The flow volume control unit determines the flow volume of the grinding liquid according to the grinding resistance, and controls the flow volume control motor to move the valve element to the position according to the determined flow volume.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a grinding device. [Background technology]

[0002] Patent Document 1 discloses a grinding fluid supply method and grinding processing device that detects changes in tangential grinding resistance and adjusts the amount of grinding fluid supplied by changing the opening of a flow control valve in accordance with those changes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-122267 Summary of the Invention [Problem to be solved by the invention]

[0004] However, no specific studies have been conducted so far on a valve that can accurately adjust the flow rate of the grinding fluid in accordance with the grinding resistance. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms. According to one aspect of the present disclosure, there is provided a grinding apparatus comprising: a workpiece support portion for supporting a workpiece rotatably about an axis; a grinding wheel for grinding the workpiece; a grinding resistance measuring device for measuring grinding resistance when the grinding wheel grinds the workpiece; a grinding fluid supplying device for supplying a grinding fluid to a vicinity of a grinding point where the grinding wheel grinds the workpiece; and a flow rate control unit for controlling the amount of the grinding fluid supplied to the grinding point by the grinding fluid supplying device, wherein the grinding fluid supplying device comprises a flow path portion having a linear piping portion through which the grinding fluid flows, a cylinder portion connected obliquely to the flow path portion, a piston-shaped valve element disposed inside the cylinder portion and movable along the axis of the cylinder portion to any position within a movable range from the cylinder portion to the inside of the flow path portion, and a flow rate control motor for changing the position of the valve element, wherein the flow rate control unit determines a flow rate of the grinding fluid in accordance with the grinding resistance and controls the flow rate control motor to move the valve element to a position corresponding to the determined flow rate.

[0006] (1) According to one aspect of the present disclosure, there is provided a grinding apparatus comprising: a workpiece support portion that supports a workpiece rotatably about an axis; a grinding wheel that grinds the workpiece; a grinding resistance measurement device that measures grinding resistance when the grinding wheel grinds the workpiece; a grinding fluid supplying device that supplies grinding fluid to a vicinity of a grinding point where the grinding wheel grinds the workpiece; and a flow rate control unit that controls the amount of the grinding fluid supplied to the grinding point by the grinding fluid supplying device, wherein the grinding fluid supplying device has a flow path portion through which the grinding fluid flows, a cylinder portion connected to the flow path portion, a piston-shaped valve element that can be moved to any position within a movable range from the cylinder portion to within the flow path portion, and a flow rate control motor that changes the position of the valve element, wherein the flow rate control unit determines a flow rate of the grinding fluid in accordance with the grinding resistance and controls the flow rate control motor to move the valve element to a position corresponding to the determined flow rate. According to the grinding device of this embodiment, the position of the valve element can be changed by the flow control motor to a position according to the flow rate of the grinding fluid, so that the flow rate of the grinding fluid can be adjusted with high precision according to the grinding resistance. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an explanatory diagram showing a schematic configuration of a grinding device. [Figure 2] FIG. 2 is a diagram illustrating the structure of a valve portion. [Figure 3] FIG. 2 is a cross-sectional view of a cross section perpendicular to the axis of the valve body. [Figure 4] FIG. 10 is a diagram illustrating the relationship between grinding resistance and the flow rate of grinding fluid. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: Fig. 1 is an explanatory diagram showing a schematic configuration of a grinding apparatus 100. Fig. 1 shows a Z axis and an X axis that are perpendicular to each other. The Z axis and the X axis are axes along a horizontal plane.

[0009] The grinding device 100 is a machine tool that grinds the surface of a workpiece W by bringing a grinding wheel 31 into contact with the workpiece W as an object to be ground and by moving the workpiece W and the grinding wheel 31 relative to each other. In this embodiment, the grinding device 100 is a cylindrical grinding machine. The workpiece W has a cylindrical shape and is made of, for example, metal or ceramic. However, the shape and material of the workpiece W are not limited to these.

[0010] The grinding machine 100 includes a bed 10, a workpiece support portion 20, a grinding wheel head 30, a Z-axis feed device 40, an X-axis feed device 50, a grinding fluid supply device 60, and a control device .

[0011] The bed 10 supports the workpiece support 20, the wheel head 30, the Z-axis feed device 40, and the X-axis feed device 50. The bed 10 is made of, for example, cast iron. On the upper surface of the bed 10, a sliding surface is formed for the workpiece support 20 to move along the Z-axis direction, and a sliding surface is formed for the wheel head 30 to move along the X-axis direction.

[0012] The upper surface of the bed 10 is provided with a grinding fluid receiver 11 and a discharge port 12. The grinding fluid receiver 11 is a groove provided around the two sliding surfaces described above. When the grinding wheel 31 grinds the workpiece W, the grinding fluid supplied to the vicinity of the point where the grinding wheel 31 grinds the workpiece W flows into the grinding fluid receiver 11. The grinding fluid is, for example, a coolant. The discharge port 12 is a hole formed in the bottom surface of the grinding fluid receiver 11. The discharge port 12 discharges the grinding fluid flowing in the grinding fluid receiver 11 to the outside of the bed 10. Hereinafter, the point where the grinding wheel 31 grinds the workpiece W will be referred to as the grinding point.

[0013] The workpiece support unit 20 supports both ends of the workpiece W in the Z-axis direction so that the workpiece W can rotate around a workpiece rotation axis O1. The workpiece rotation axis O1 is the axis of the workpiece W, and its direction is parallel to the Z-axis. The workpiece support unit 20 includes a table 21, a headstock 22, and a tailstock 23.

[0014] The table 21 is disposed on the upper surface of the bed 10. A headstock 22 and a tailstock 23 are attached to the upper surface of the table 21.

[0015] The headstock 22 includes a spindle 24, a chuck 25, and a spindle rotation drive device 26. The workpiece W is attached to the spindle 24 by having one end in the Z-axis direction gripped by the chuck 25. The spindle rotation drive device 26 drives the spindle 24 to rotate. The axis of the spindle 24 is aligned with the workpiece rotation axis O1. Therefore, when the spindle 24 rotates, the workpiece W rotates around the workpiece rotation axis O1 via the chuck 25. The rotation speed of the workpiece W is controlled by the rotation speed of the motor of the spindle rotation drive device 26.

[0016] The tailstock 23 is disposed opposite the headstock 22 in the Z-axis direction with the workpiece W sandwiched therebetween. The tailstock 23 is equipped with a center 27. The center 27 supports the other end of the workpiece W in the Z-axis direction so that the workpiece W can rotate about the workpiece rotation axis O1. In other words, the workpiece W is supported by the chuck 25 and the center 27 so as to be rotatable about the workpiece rotation axis O1.

[0017] The wheel head 30 is disposed on the upper surface of the bed 10. The wheel head 30 includes a grinding wheel 31, a grinding wheel cover 32, a grinding wheel spindle 33, a grinding wheel drive motor 34, and a grinding resistance measuring device 35.

[0018] The grinding wheel 31 grinds the surface of the workpiece W. The grinding wheel 31 is composed of a core and a grinding wheel layer. The core is disk-shaped and made of metal such as iron. The core is detachably connected to the grinding wheel spindle 33 by bolts or the like. The grinding wheel layer is disk-shaped and provided on the outer periphery of the core. The grinding wheel layer is formed by mixing abrasive grains and a binder and baking the mixture. For example, CBN (Cubic Boron Nitride) or diamond is used as the abrasive grains. The grinding wheel layer comes into contact with the workpiece W, thereby grinding the outer periphery of the workpiece W.

[0019] The grinding wheel cover 32 is provided so as to cover a part of the outer periphery of the grinding wheel 31. The grinding wheel cover 32 prevents the grinding fluid supplied to the vicinity of the grinding point from scattering when the grinding wheel 31 grinds the workpiece W.

[0020] The grinding wheel spindle 33 supports the grinding wheel 31 so that it can rotate around its axis. The grinding wheel spindle 33 is rotatably supported on the grinding wheel head 30 via a bearing (not shown). The axis of the grinding wheel spindle 33 coincides with the grinding wheel rotation axis O2, which is the axis of the grinding wheel 31. In this embodiment, the direction of the grinding wheel rotation axis O2 is parallel to the Z axis.

[0021] The grinding wheel drive motor 34 is built into the wheel head 30 coaxially with the grinding wheel spindle 33. The grinding wheel drive motor 34 drives the grinding wheel spindle 33 to rotate about the grinding wheel rotation axis O2. As the grinding wheel spindle 33 rotates, the grinding wheel 31 is driven to rotate about the grinding wheel rotation axis O2. The grinding wheel drive motor 34 is a three-phase induction motor and has a rated rotation speed.

[0022] The grinding resistance measuring device 35 measures the grinding resistance when the grinding wheel 31 grinds the workpiece W. In this embodiment, the grinding resistance measuring device 35 is an ammeter that measures the current value of the motor that rotates the grinding wheel 31, and measures the current value of the motor that rotates the grinding wheel 31 as a value that represents the grinding resistance when the grinding wheel 31 grinds the workpiece W. The greater the grinding resistance, the greater the current value of the motor that rotates the grinding wheel 31. This is because, as the grinding resistance increases, the rotation speed of the grinding wheel 31 decreases, and the motor that rotates the grinding wheel 31 tries to maintain the rotation speed of the grinding wheel 31, so the current value of the motor that rotates the grinding wheel 31 increases.

[0023] Z-axis feed device 40 has a Z-axis motor 41. Z-axis motor 41 provides a driving force to Z-axis feed device 40. Z-axis feed device 40 is connected to table 21 and moves table 21 along the Z-axis direction. The Z-axis direction is also called the feed direction.

[0024] The X-axis feed device 50 has an X-axis motor 51. The X-axis motor 51 provides a driving force to the X-axis feed device 50. The X-axis feed device 50 is connected to the wheel head 30 and moves the wheel head 30 along the X-axis direction. The X-axis direction is also called the cutting direction of the grinding wheel 31.

[0025] The grinding fluid supply device 60 includes a grinding fluid storage tank 61, a pump 62, a valve unit 63, and a nozzle 64. The grinding fluid storage tank 61, the pump 62, the valve unit 63, and the nozzle 64 are connected by piping in the above-mentioned order.

[0026] The grinding fluid storage tank 61 is installed beside the bed 10. The grinding fluid storage tank 61 stores the grinding fluid discharged from the discharge port 12 to the outside of the bed 10. The grinding fluid discharged from the discharge port 12 contains chips generated during the grinding process of the workpiece W. The grinding fluid storage tank 61 has a filter (not shown) for removing the above-mentioned chips.

[0027] The pump 62 pumps the grinding fluid stored in the grinding fluid storage tank 61 to the valve portion 63 .

[0028] The valve unit 63 adjusts the flow rate of the grinding fluid pressure-fed by the pump 62, and supplies the grinding fluid with the adjusted flow rate to the nozzle 64. The structure of the valve unit 63 will be described later.

[0029] The nozzle 64 is attached to the grinding wheel cover 32. The nozzle 64 supplies the grinding fluid, the flow rate of which is adjusted by the valve unit 63, to the vicinity of the grinding point. The grinding fluid is sprayed from the tip of the nozzle 64 toward the vicinity of the grinding point.

[0030] Fig. 2 is a diagram illustrating the structure of the valve unit 63. Fig. 3 is a cross-sectional view of the valve element 630 taken along line III-III, which is a cross-section perpendicular to the axis O3 of the valve element 630 shown in Fig. 2. The valve unit 63 includes a flow path unit 610, a cylinder unit 620, the valve element 630, and a motor unit 640.

[0031] The flow path portion 610 is a member having a space therein through which the grinding fluid flows. In Fig. 2, the direction in which the grinding fluid flows in the flow path portion 610 is indicated by an arrow. A cylinder portion 620 is connected to the flow path portion 610. The flow path portion 610 includes a connection portion 611 and a piping portion 612.

[0032] The connecting portion 611 is provided at a portion where the flow path portion 610 and the cylinder portion 620 are connected. The connecting portion 611 has a valve seat 613, which is a surface that comes into contact with a ring 631 of a valve body 630, which will be described later. The valve seat 613 has a substantially annular shape. When the ring 631 is not in contact with the valve seat 613, the grinding fluid flows over the surface of the valve seat 613.

[0033] The piping section 612 is provided on both sides of the connection section 611 and the cylinder section 620. The piping section 612 has a cylindrical shape. The piping section 612 is a portion to which another pipe is connected.

[0034] The cylinder portion 620 is a substantially cylindrical member and is connected obliquely to the flow path portion 610. Specifically, the cylinder portion 620 is connected to the flow path portion 610 so that the angle formed between the axis O3 of the valve body 630 provided inside the cylinder portion 620 and the direction in which the grinding fluid flows inside the flow path portion 610 becomes an acute angle on the downstream side of the flow path portion 610. The axis of the cylinder portion 620 coincides with the axis O3 of the valve body 630.

[0035] The valve element 630 is provided inside the cylinder portion 620. The valve element 630 has a generally cylindrical piston shape. The valve element 630 includes a ring 631 and a key 632. The ring 631 is an annular elastic body and is fitted into an annular groove formed on the outer periphery of the tip end of the valve element 630. In this specification, the term "tip end" refers to the end on the flow path portion 610 side, and the term "rear end" refers to the end opposite the flow path portion 610 side. The key 632 is provided in a key groove (not shown) formed on the outer periphery of the rear end side of the valve element 630 so that a portion of the key groove protrudes from the valve element 630. The valve element 630 is provided so as to be movable back and forth only in a direction along the axis O3 of the valve element 630. The valve element 630 is also movable back and forth only in a direction along the axis O3 of the valve element 630 within the flow path portion 610, as in the cylinder portion 620. The valve element 630 is provided so as to be movable to any position within a movable range from the cylinder portion 620 to the inside of the flow path portion 610. The flow rate of the grinding fluid flowing through the flow path portion 610 changes as the valve element 630 approaches or moves away from the valve seat 613. When the valve element 630 is closest to the valve seat 613, the ring 631 abuts against the valve seat 613 to close the flow path portion 610.

[0036] The motor section 640 moves the valve element 630 in a direction along its axis O3. The motor section 640 includes a flow control motor 641, a valve housing 643, a coupling 645, and a screw shaft 646.

[0037] The flow rate control motor 641 is, for example, a servo motor having an encoder.

[0038] The valve housing 643 is a component having an internal space. A coupling 645 and a screw shaft 646 are provided inside the valve housing 643. A flow control motor 641 is attached to the rear end side of the valve housing 643. The valve housing 643 is fitted into the cylinder portion 620 so that its front end is located between the cylinder portion 620 and the valve body 630. A key groove 644, into which a key 632 of the valve body 630 is fitted, is formed inside the front end side of the valve housing 643 in a direction along the axis O3 of the valve body 630. By fitting the key 632 into the key groove 644, rotation of the valve body 630 around the axis O3 of the valve body 630 is restricted.

[0039] The screw shaft 646 is a generally cylindrical member with a screw thread formed on its outer periphery. The tip of the screw shaft 646 is threaded into a threaded hole 633 formed in the rear end of the valve body 630.

[0040] The coupling 645 connects the output shaft 642, which is the output shaft of the flow control motor 641, to the screw shaft 646. The coupling 645 transmits the rotation of the output shaft 642 to the screw shaft 646.

[0041] As described above, the valve disc 630 is connected to the flow control motor 641 via the threaded shaft 646 and the coupling 645. The rotational motion of the output shaft 642 of the flow control motor 641 is converted into linear motion of the valve disc 630 in the direction along the axis O3 of the valve disc 630 by the threaded shaft 646, the threaded hole 633 of the valve disc 630, and the key 632. Therefore, the valve disc 630 is moved in the direction along the axis O3 of the valve disc 630 by the driving force of the flow control motor 641. The flow control motor 641 can position the valve disc 630 at any position between a fully closed position where the valve disc 630 abuts against the valve seat 613 and blocks the flow path portion 610, and a fully open position where the entire valve disc 630 is outside the flow path portion 610, and can maintain the position of the valve disc 630.

[0042] 1 includes a CPU 71 and a storage unit 72. The control unit 70 is electrically connected to the spindle rotation drive unit 26, the grinding wheel drive motor 34, the Z-axis feed unit 40, the X-axis feed unit 50, the grinding resistance measuring device 35, and the flow control motor 641 of the valve unit 63. The control unit 70 controls the operation of the grinding apparatus 100 by transmitting control commands to the spindle rotation drive unit 26, the grinding wheel drive motor 34, the Z-axis feed unit 40, the X-axis feed unit 50, and the flow control motor 641.

[0043] The storage unit 72 stores a program for executing grinding of the workpiece W.

[0044] The CPU 71 executes a program stored in the storage unit 72, thereby functioning as an operation control unit 711, an information acquisition unit 712, and a flow rate control unit 713. Some or all of these functional units may be realized by circuits.

[0045] The operation control unit 711 controls the rotation speed of the workpiece W, the rotation speed of the grinding wheel 31, the speed of the workpiece support unit 20 in the feed direction, and the cutting speed of the grinding wheel 31. Specifically, the operation control unit 711 controls the rotation speed of the motor of the spindle rotation drive device 26, thereby controlling the rotation speed of the spindle 24 and the rotation speed of the workpiece W attached to the spindle 24. The operation control unit 711 also controls the rotation speed of the grinding wheel drive motor 34, thereby controlling the rotation speed of the grinding wheel 31. The operation control unit 711 also controls the rotation speed of the Z-axis motor 41, thereby controlling the speed at which the workpiece support unit 20 moves in the feed direction. The operation control unit 711 also controls the cutting speed of the grinding wheel 31, which is the speed at which the wheel head 30 moves in the cutting direction of the grinding wheel 31, by controlling the rotation speed of the X-axis motor 51.

[0046] The information acquisition unit 712 acquires the grinding resistance when the grinding wheel 31 grinds the workpiece W from the grinding resistance measurement device 35.

[0047] The flow rate control unit 713 determines the flow rate of the grinding fluid according to the grinding resistance acquired by the information acquisition unit 712. The flow rate control unit 713 controls the flow rate control motor 641 to move the valve element 630 to a position according to the determined flow rate of the grinding fluid. The flow rate of the grinding fluid according to the grinding resistance and the position of the valve element 630 according to the flow rate of the grinding fluid are stored in advance in the storage unit 72.

[0048] FIG. 4 illustrates the relationship between grinding resistance and the flow rate of grinding fluid. In the graph shown in FIG. 4, the horizontal axis represents elapsed time. The vertical axis represents grinding resistance, the flow rate of grinding fluid, and the cutting position of the grinding wheel 31. Here, the cutting position of the grinding wheel 31 refers to the position of the grinding wheel 31 relative to the workpiece W in the X-axis direction. FIG. 4 shows changes in grinding resistance, the flow rate of grinding fluid, and the cutting position of the grinding wheel 31 during the grinding process of one workpiece W. In FIG. 4, P1, P2, P3, and P4 represent the dry grinding process, rough grinding process, finish grinding process, and spark-out period, respectively, during the grinding process of one workpiece W. In FIG. 4, the slope of the graph of the cutting position of the grinding wheel 31 represents the cutting speed of the grinding wheel 31.

[0049] In the dry grinding process P1, the grinding resistance is zero because there is no contact between the grinding wheel 31 and the workpiece W. In the dry grinding process P1, the flow rate control unit 713 determines the flow rate of the grinding fluid to be a very small amount, and fixes the valve body 630 to a position close to the fully closed position.

[0050] In the rough grinding process P2, the grinding wheel 31 and the workpiece W first come into contact at a high cutting speed, causing a rapid increase in grinding resistance. At this time, the flow rate control unit 713 determines the flow rate of the grinding fluid so that the greater the grinding resistance, the greater the flow rate of the grinding fluid. As the flow rate of the grinding fluid increases, the flow rate control unit 713 moves the position of the valve element 630 closer to the fully open position. As the grinding resistance becomes constant as the machining of the workpiece W progresses, the flow rate control unit 713 sets the flow rate of the grinding fluid to a constant flow rate corresponding to the grinding resistance and fixes the position of the valve element 630. Then, when the operation control unit 711 slows the cutting speed of the grinding wheel 31, causing the grinding resistance to decrease, the flow rate control unit 713 determines the flow rate of the grinding fluid so that the smaller the grinding resistance, the less the flow rate of the grinding fluid. As the flow rate of the grinding fluid decreases, the flow rate control unit 713 moves the position of the valve element 630 closer to the fully closed position. When the grinding resistance becomes constant again as the machining of the workpiece W progresses, the flow rate control unit 713 sets the flow rate of the grinding fluid to a constant flow rate according to the grinding resistance and fixes the position of the valve body 630.

[0051] In the finish grinding process P3, the cutting speed of the grinding wheel 31 is slower than in the rough grinding process P2, so the grinding resistance is reduced more than in the rough grinding process P2. When the grinding resistance decreases, the flow rate control unit 713 determines the flow rate of the grinding fluid so that the flow rate of the grinding fluid decreases as the grinding resistance decreases, just as in the rough grinding process P2, and moves the position of the valve element 630 closer to the fully closed position as the determined flow rate of the grinding fluid decreases. The determination of the flow rate of the grinding fluid and the movement of the valve element 630 by the flow rate control unit 713 described above are performed regardless of changes in the degree of reduction in the grinding resistance over time.

[0052] In the spark-out P4, the grinding resistance decreases over time because the grinding wheel 31 does not move. At this time, the flow rate control unit 713 determines the flow rate of the grinding fluid so that the flow rate of the grinding fluid decreases as the grinding resistance decreases, as in the finish grinding process P3, and moves the position of the valve body 630 closer to the fully closed position as the determined flow rate of the grinding fluid decreases.

[0053] According to the grinding apparatus 100 described above, the flow rate control unit 713 determines the flow rate of the grinding fluid in accordance with the grinding resistance measured by the grinding resistance measurement device 35, and controls the flow rate control motor 641 to move the valve element 630 to a position corresponding to the determined flow rate of the grinding fluid. The flow rate control unit 713 determines the flow rate of the grinding fluid so that the greater the grinding resistance, the greater the flow rate of the grinding fluid. As the flow rate of the grinding fluid increases, the flow rate control unit 713 moves the position of the valve element 630 closer to the fully open position. The flow rate control unit 713 also determines the flow rate of the grinding fluid so that the smaller the grinding resistance, the less the flow rate of the grinding fluid. As the flow rate of the grinding fluid decreases, the flow rate control unit 713 moves the position of the valve element 630 closer to the fully closed position. Therefore, the grinding apparatus 100 can change the amount of grinding fluid supplied to the grinding point in accordance with the grinding resistance. Therefore, the grinding apparatus 100 can effectively supply the grinding fluid to the grinding point by suppressing losses of the grinding fluid, such as supplying more grinding fluid than necessary to the grinding point when the grinding resistance is low. Therefore, the grinding apparatus 100 can reduce the power costs of the grinding fluid supply device 60. Furthermore, because the flow control motor 641 can hold the valve body 630 at any position between the fully open position and the fully closed position, the grinding apparatus 100 can continuously change the amount of grinding fluid supplied to the grinding point. As a result, the grinding apparatus 100 can accurately adjust the flow rate of the grinding fluid according to the grinding resistance.

[0054] In addition, in this embodiment, the cylinder portion 620 in which the piston-shaped valve body 630 is arranged is connected at an angle to the flow path portion 610, so that chips that could not be removed by the filter of the grinding fluid storage tank 61 can be prevented from clogging the gap between the valve body 630 and the valve housing 643, preventing the valve body 630 from becoming difficult to move.

[0055] B. Other Embodiments: (B-1) In the above embodiment, the wheel head 30 is provided so as to be movable in a direction along the X-axis perpendicular to the workpiece rotation axis O1. However, the wheel head 30 may be provided so as to be movable in a direction inclined relative to the workpiece rotation axis O1.

[0056] (B-2) In the above embodiment, the grinding resistance measuring device 35 is an ammeter that measures the current value of the motor that rotates the grinding wheel 31. In contrast, the grinding resistance measuring device 35 may be, for example, an ammeter that measures the current value of the Z-axis motor 41 that moves the table 21 in the direction along the Z-axis, or an AE sensor that detects acoustic emissions (AE) generated when the workpiece W is ground by the grinding wheel 31.

[0057] (B-3) In the above embodiment, the grinding device 100 is a cylindrical grinding machine. However, the grinding device 100 may be an internal grinding machine, a centerless grinding machine, or a surface grinding machine.

[0058] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0059] 10...bed, 11...grinding fluid receiver, 12...discharge port, 20...workpiece support portion, 21...table, 22...headstock, 23...tailstock, 24...spindle, 25...chuck, 26...spindle rotation drive device, 27...center, 30...grinding wheel head, 31...grinding wheel, 32...grinding wheel cover, 33...grinding wheel spindle, 34...grinding wheel drive motor, 35...grinding resistance measuring device, 40...Z-axis feed device, 41...Z-axis motor, 50...X-axis feed device, 51...X-axis motor, 60...grinding fluid supply device, 61...grinding fluid storage tank, 62...pump, 63...valve portion, 64...nozzle, 70...control device, 71...CPU, 72...memory portion, 100... Grinding device, 610...flow path section, 611...connection section, 612...piping section, 613...valve seat, 620...cylinder section, 630...valve body, 631...ring, 632...key, 633...threaded hole, 640...motor section, 641...flow control motor, 642...output shaft, 643...valve housing, 644...key groove, 645...coupling, 646...screw shaft, 711...motion control section, 712...information acquisition section, 713...flow control section, O1...workpiece rotation axis, O2...grinding wheel rotation axis, O3...valve body axis, P1...air grinding process, P2...rough grinding process, P3...finish grinding process, P4...spark out, W...workpiece

Claims

1. A grinding device comprising: a workpiece support portion that supports the workpiece so that the workpiece can rotate about an axis; a grinding wheel for grinding the workpiece; a grinding resistance measuring device that measures the grinding resistance when the grinding wheel grinds the workpiece; a grinding fluid supply device that supplies a grinding fluid to the vicinity of a grinding point where the grinding wheel grinds the workpiece; a flow rate control unit that controls the amount of the grinding fluid that the grinding fluid supply device supplies to the grinding point, The grinding fluid supply device is a flow path portion having a linear piping portion through which the grinding fluid flows; a cylinder portion connected obliquely to the flow path portion; a piston-shaped valve element provided inside the cylinder portion and movable along an axis of the cylinder portion to any position within a movable range from the cylinder portion to the inside of the flow path portion; a flow control motor for changing the position of the valve element; The flow rate control unit determining a flow rate of the grinding fluid in accordance with the grinding resistance; controlling the flow control motor to move the valve element to a position according to the determined flow rate; Grinding equipment.

2. A grinding device according to claim 1, the cylinder portion is connected to the flow path portion such that an angle formed between the axis and a direction in which the grinding fluid flows through the flow path portion becomes an acute angle on the downstream side of the flow path portion. Grinding equipment.

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