Surface grinding equipment

Abstract

To provide a surface grinding device which has high measurement accuracy of a workpiece surface by a detection sensor and can highly accurately grind a workpiece.SOLUTION: A surface grinding device comprises: a grinding wheel 2 which grinds a workpiece W held on a work table 4 while rotating; a wheel shaft head 3 which supports the grinding wheel 2; a detection sensor 10 which detects the position of a processing object surface of the workpiece W; and a sensor support mechanism 20 which movably supports the detection sensor 10. The sensor support mechanism 20 comprises: a turning cam shaft 21 which extends toward the holding surface of the work table 4 and can freely reciprocally move and rotate in the direction of the shaft center; and an arm member 27 which is provided in the turning cam shaft 21 and supports the detection sensor 10 at the position offset in the radial direction. The detection sensor 10 approaches or separates from the work table 4 by turning while moving in the direction of the shaft center. With this, the measurement accuracy can be improved by bringing the detection sensor 10 close to a grinding point of the workpiece W.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a surface grinding machine, and more particularly to a surface grinding machine equipped with a sensor mechanism capable of accurately detecting the position of a surface to be machined of a workpiece. [Background technology]

[0002] 2. Description of the Related Art In surface grinding devices, which grind the top surface of a workpiece placed on a worktable using a grinding wheel supported on a wheel spindle that extends approximately horizontally along the top surface of the worktable, some devices are equipped with a contact-type detection sensor that detects the position of the workpiece by contacting the surface of the workpiece.

[0003] For example, Patent Document 1 discloses a surface grinding machine having a work table that can move back and forth in the left-right direction and a grinding wheel that can move in the front-back direction, in which a sensor unit equipped with a touch probe is attached to the side of the wheel head.

[0004] The touch probe disclosed in this document has a stylus at the tip that contacts the top surface of a reference block provided on a work table and the top surface of a workpiece, thereby detecting the height from the work table to the top surface of the reference block and the top surface of the workpiece, and the amount of removal to be ground is calculated by a calculation means.

[0005] For example, Patent Document 2 discloses an automatic grinding device that has a contact sensor that detects the position of the workpiece in the cutting direction and feed direction, calculates the range of relative movement of the wheel and table based on the position information detected by the sensor, and automatically starts machining using the wheel.

[0006] The detection sensor disclosed in this document has a probe that is provided on the side or front of the wheel cover and protrudes downward, and a substantially spherical contactor provided at the lower end of the probe. The contactor comes into contact with the workpiece or table, allowing the detection sensor to detect the position of the workpiece or table. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-52444 A [Patent Document 2] JP 2020-110893 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the above-mentioned conventional surface grinding apparatus has some issues to be improved in terms of measurement of the workpiece by the detection sensor in order to improve the accuracy of the grinding process.

[0009] Specifically, in conventional surface grinding devices, even if a sensor such as a touch probe that detects the position information of the workpiece is provided near the grinding wheel, the measurement point measured by the detection sensor is located away from the point at which the workpiece is ground by the grinding wheel.

[0010] In other words, even if the detection sensor is provided near the grinding wheel, for example, on the side of the wheel head as in the conventional technology disclosed in Patent Documents 1 and 2, and the detection sensor is moved vertically, the contact position between the contactor of the detection sensor and the workpiece will be away from the contact position between the grinding wheel and the workpiece.

[0011] Therefore, in conventional surface grinding devices, measurement errors could become large due to the distance between the measurement point measured by the detection sensor and the grinding point measured by the grinding wheel, making it difficult to improve the accuracy of measurements made by the detection sensor.

[0012] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a surface grinding device that has high measurement accuracy of the workpiece surface using a detection sensor and can grind the workpiece with high precision. [Means for solving the problem]

[0013] The surface grinding device of the present invention comprises a work table for holding a workpiece, a grinding wheel for grinding the workpiece held on the worktable while rotating it, a wheel spindle head having a wheel shaft for supporting the grinding wheel, a detection sensor for detecting the position of a surface to be machined of the workpiece, and a sensor support mechanism for movably supporting the detection sensor, the sensor support mechanism having a rotating cam shaft extending toward a holding surface of the worktable for holding the workpiece and reciprocating in the direction of its axis and rotatable about the axis, and an arm member for supporting the detection sensor at a position radially offset from the axis while moving in a direction along the axis and rotating about the axis to move toward and away from the worktable. The workpiece surface is detected at a position close to the grinding wheel by rotating the workpiece around the axis. It is characterized by: Effect of the Invention

[0014] According to the surface grinding device of the present invention, a detection sensor for detecting the position of the surface to be machined of a workpiece and a sensor support mechanism for movably supporting the detection sensor, the sensor support mechanism having a swivel cam shaft extending toward a holding surface of a worktable for holding the workpiece and reciprocating in the direction of the axis and rotatable about the axis, and an arm member for supporting the detection sensor at a position radially offset from the axis, the detection sensor moving in a direction along the axis and revolving about the axis to approach and move away from the worktable. With this configuration, the surface grinding device can bring the measurement point of the detection sensor closer to the grinding point of the workpiece by the grinding wheel, thereby increasing the measurement accuracy of the workpiece surface by the detection sensor, and grinding the workpiece with high accuracy.

[0015] According to the surface grinding device of the present invention, the sensor support mechanism includes a driving means for feeding the swivel cam shaft in the direction of the axis, a cam follower having a roller for movably supporting the swivel cam shaft, and a cam groove formed on the swivel cam shaft in which the roller is fitted and supported by the cam follower, the cam groove extending in the direction of the axis and inclining obliquely in the circumferential direction near the upper end. With this configuration, the sensor support mechanism can suitably feed the detection sensor from a retracted position away from the workpiece where the workpiece is not measured to a detection position where the workpiece is measured, or in the opposite direction.

[0016] For example, when moving from the retracted position to the detection position, the detection sensor is pushed by the driving means and sent in the direction of the axis of the swivel cam shaft to approach the workpiece. Then, when the detection sensor approaches the workpiece, it rotates around the axis of the swivel cam shaft to approach the grinding point of the workpiece. Therefore, the detection sensor moves from the retracted position to the detection position close to the grinding point of the workpiece along a suitable trajectory that does not collide with the wheel head, etc. Then, the detection sensor performs highly accurate measurement in the vicinity of the grinding point of the workpiece.

[0017] According to the surface grinding device of the present invention, the driving means may be an air cylinder that drives the swivel camshaft with a piston rod connected to the swivel camshaft. With this configuration, the detection sensor is driven by air pressure supplied to the air cylinder as a power source in the direction of the axis of the swivel camshaft to approach the workpiece, and also rotates around the axis of the swivel camshaft to approach the grinding point of the workpiece. Thus, the detection sensor is moved with high accuracy and efficiency by utilizing the air pressure.

[0018] According to the surface grinding device of the present invention, the cam followers may be provided in pairs so as to face each other with the swivel cam shaft as a center, and the cam grooves may be formed in pairs on the outer periphery of the swivel cam shaft so as to correspond to the cam followers. This enables highly accurate and efficient linear swivel feeding of the detection sensor.

[0019] According to the surface grinding device of the present invention, the detection sensor rotates about the axis and detects the workpiece surface at a position close to the grinding wheel, thereby enabling highly accurate measurement with small error.

[0020] According to the surface grinding device of the present invention, the detection sensor may be a touch probe that detects the position of the workpiece by contacting the workpiece surface with a contact of the detection sensor, thereby making it possible to detect the position of the workpiece with high accuracy by contacting the workpiece surface with a contact of the detection sensor. [Brief description of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a schematic configuration of a surface grinding device according to an embodiment of the present invention; [Diagram 2] 2 is a front view showing the vicinity of a grinding wheel and a sensor mechanism of the surface grinding device according to the embodiment of the present invention. FIG. [Diagram 3] 2 is a side view showing the vicinity of a grinding wheel and a sensor mechanism of the surface grinding device according to the embodiment of the present invention. FIG. [Figure 4] 2 is an exploded perspective view showing a schematic configuration of a sensor support mechanism of the surface grinding machine according to the embodiment of the present invention; FIG. [Diagram 5] 5 is a view showing the vicinity of a cam groove of a sensor support mechanism of the surface grinding machine according to the embodiment of the present invention. FIG. [Figure 6] 2A and 2B are a plan view and a side view showing a state in which a detection sensor of a surface grinding device according to an embodiment of the present invention is in a retracted position. [Figure 7] 3A and 3B are a plan view and a side view showing a state in which a detection sensor of the surface grinding device according to the embodiment of the present invention is fed. [Figure 8] 1A and 1B are a plan view and a side view showing a state in which a detection sensor of a surface grinding device according to an embodiment of the present invention is at a detection position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A surface grinding device according to an embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a surface grinding device 1 according to an embodiment of the present invention.

[0023] 1, the surface grinding device 1 is a machine tool that grinds the processed surface of a workpiece W. The surface grinding device 1 is, for example, a CNC (Computerized Numerical Control) grinding machine, and has an operation panel (not shown) that performs automatic numerical control.

[0024] The surface grinding device 1 has a grinding wheel 2 as a tool for grinding the workpiece W, and a work table 4 for holding the workpiece W, and the surface of the workpiece W, which is the surface to be processed, is ground by the rotating grinding wheel 2.

[0025] The surface grinding device 1 may be, for example, a CNC surface grinding machine that performs surface grinding on the upper surface of the workpiece W, or a CNC form grinding machine that can grind complex shapes. In addition, the surface grinding device 1 may be, for example, a gate-type grinding machine, or may be another type of grinding machine.

[0026] The work table 4 is capable of reciprocating horizontally in the left-right direction when viewed from the front (hereinafter referred to as the "X direction" where appropriate). The grinding wheel 2 is mounted on a wheel spindle head 3 configured to reciprocate vertically (hereinafter referred to as the "Y direction" where appropriate). The wheel spindle head 3 supporting the grinding wheel 2 is supported by a saddle 15 configured to reciprocate horizontally in the front-rear direction (hereinafter referred to as the "Z direction" where appropriate).

[0027] The surface grinding device 1 may be a column-type surface grinding machine, in which case the grinding head 3 is supported by a column configured to be capable of reciprocating in the Z direction. Also, the work table 4 may be configured to be capable of reciprocating in the Z direction.

[0028] A wheel spindle (not shown) that supports the grinding wheel 2 is rotatably provided on the wheel spindle head 3. The grinding wheel 2 supported by the wheel spindle head 3 rotates together with the wheel spindle and moves together with the wheel spindle head 3 in the Y and Z directions.

[0029] The grinding wheel 2 is formed in a substantially circular disk shape. The surface grinding device 1 has a rotation drive means (not shown), such as a motor, for rotating the grinding wheel 2. The grinding wheel 2 comes into contact with the surface of the workpiece W while rotating, thereby grinding the surface of the workpiece W.

[0030] The grinding wheel 2 is covered by a wheel cover 16 that is open downward. As described above, the grinding wheel 2 is supported by the wheel head 3 that moves in the Y and Z directions. Therefore, the grinding wheel 2 moves in conjunction with the wheel head 3 relative to the work table 4 in the Y and Z directions.

[0031] A work table 4 is provided below the grinding wheel 2 as a support means for placing the workpiece W. The work table 4 is, for example, an electromagnetic chuck or the like equipped with an electromagnet or the like inside, and can support the placed workpiece W by magnetic force so as not to move it.

[0032] As described above, the work table 4 is configured to be movable relative to the grinding wheel 2 in the X direction, which is the feed direction. This makes it possible to adjust the relative position of the grinding wheel 2 and the work W in the X direction by moving the work W. In this way, by moving the work table 4 and the wheel head 3 relative to each other, the relative position of the grinding wheel 2 and the work W can be changed in three axial directions, i.e., the X direction, the Y direction, and the Z direction.

[0033] The grinding wheel 2 is supported by a grinding wheel head 3. The grinding wheel 2 and the work table 4 are supported by a workpiece W. The grinding wheel 2 and the workpiece W are supported by a feed means (not shown) which is numerically controlled by a numerical control means provided on an operation panel (not shown), and move back and forth relative to each other in the aforementioned directions.

[0034] The grinding area where the grinding wheel 2 and the work table 4 are arranged may be covered by a housing (not shown). The housing has an opening for an operator to set and remove the work W, and the opening is provided with a door (not shown) that can be opened and closed.

[0035] The surface grinding device 1 is equipped with a sensor mechanism 5 that detects the position of the processed surface of the workpiece W. The sensor mechanism 5 has a detection sensor 10 that detects the position of the processed surface of the workpiece W, and a sensor support mechanism 20 that is provided on the grinding head 3 and movably supports the detection sensor 10.

[0036] The detection sensor 10 detects the position of the workpiece W in the cutting direction of the grinding wheel 2, i.e., the Y direction, and also detects the position of the workpiece W in the feed directions perpendicular to the cutting direction, i.e., the X and Z directions. For example, the detection sensor 10 is a contact type sensor having a probe 11 protruding downward and a contactor 12 provided at the tip of the probe.

[0037] In this way, since the detection sensor 10 is a touch probe that contacts the workpiece surface to detect its position, the contactor 12 of the detection sensor 10 contacts the workpiece surface of the workpiece W, thereby enabling the position of the workpiece W to be detected with high accuracy.

[0038] In addition, various other sensors may be used as the detection sensor 10, such as a non-contact sensor that detects the presence or absence of the workpiece W using laser light or the like, a non-contact sensor such as an air sensor, an AE sensor having a piezoelectric element that detects vibrations, etc.

[0039] The detection sensor 10 is provided on the wheel spindle head 3, and therefore moves in the Y and Z directions together with the wheel spindle head 3. The detection sensor 10 is attached to the rear of the wheel cover 16, but may be attached to the side or front of the wheel cover 16, etc.

[0040] A reference block, a reference plate, or the like (not shown) may be provided near the work table 4 to serve as a reference when the detection sensor 10 measures the position of the work W. Also, a substantially spherical reference sphere or the like to serve as a reference for position measurement may be provided on the upper surface of the reference block.

[0041] FIG. 2 is a front view showing the grinding wheel 2 and the sensor mechanism 5 of the surface grinding device 1. As shown in FIG. As shown in FIG. 2, in the surface grinding machine 1 according to this embodiment, a sensor mechanism 5 for detecting the position of the workpiece W is provided on the right side of the grinding wheel 2 when viewed from the front. In this embodiment, an example in which the sensor mechanism 5 is provided on the right side of the grinding wheel 2 is given, but the sensor mechanism 5 may be provided on the left side of the grinding wheel 2.

[0042] FIG. 3 is a side view showing the vicinity of the grinding wheel 2 and the sensor mechanism 5 of the surface grinding device 1. As shown in FIG. 3, the sensor mechanism 5 is provided on the wheel spindle head 3 on the back side of the grinding wheel 2. As described above, the sensor mechanism 5 has the detection sensor 10 that detects the position of the processed surface of the workpiece W, and the sensor support mechanism 20 that movably supports the detection sensor 10.

[0043] 2 and 3, the detection sensor 10 is supported so as to be movable between a retracted position 13 where the workpiece W is not measured and a detection position 14 where the workpiece W is measured. Specifically, the sensor support mechanism 20 has a swivel cam shaft 21 that rotatably supports the detection sensor 10. The swivel cam shaft 21 extends toward the holding surface of the work table 4 that holds the work W, and is reciprocable in the direction of the axis, i.e., the Y direction, and rotatable about the axis.

[0044] An arm member 27 supporting the detection sensor 10 is provided near the lower end of the revolving cam shaft 21 at a position radially offset from the axis of the revolving cam shaft 21. That is, the detection sensor 10 moves in the Y direction along the axis of the revolving cam shaft 21 while revolving around the axis of the revolving cam shaft 21 to approach and move away from the work table 4.

[0045] The retracted position 13 of the detection sensor 10, where the detection sensor 10 does not detect the workpiece W, is located above the grinding point of the grinding wheel 2, i.e., the lowest part of the outer periphery of the grinding wheel 2, and away from the grinding point.

[0046] In detail, the detection sensor 10 is located in a position raised to the vicinity of the central axis of the grinding wheel 2, and at a position rotated approximately 180 degrees rearward around the axis of the revolving cam shaft 21. This allows the detection sensor 10 to be out of the way when the workpiece W is machined.

[0047] The detection position 14 of the detection sensor 10 which detects the processed surface of the workpiece W is located such that the contactor 12 provided at the tip of the probe 11 is below the grinding point of the grinding wheel 2 and close to the grinding point of the grinding wheel 2.

[0048] That is, the detection sensor 10 descends in the Y direction from the retreat position 13 along the swivel cam shaft 21 and rotates together with the arm member 27 around the swivel cam shaft 21 to move to a detection position 14 close to the grinding point of the grinding wheel 2.

[0049] With this configuration, the surface grinding device 1 can bring the measurement point measured by the detection sensor 10 closer to the grinding point of the workpiece W by the grinding wheel 2, thereby improving the measurement accuracy of the surface of the workpiece W by the detection sensor 10, and enabling the workpiece W to be ground with high precision.

[0050] FIG. 4 is an exploded perspective view showing a schematic configuration of the sensor support mechanism 20. As shown in FIG. 4, the sensor support mechanism 20 includes a rotating cam shaft 21 having an arm member 27 that supports the detection sensor 10 so as to be rotatable in the Y direction, and an air cylinder 30 as a driving means for moving the detection sensor 10. The turning cam shaft 21 has a generally cylindrical shape extending in the Y direction, and as described above, is provided so as to be capable of reciprocating and rotatable along its axis.

[0051] Specifically, the revolving camshaft 21 is fitted inside a pair of upper and lower support bushes 25. The support bushes 25 are, for example, slide bearings, and support the revolving camshaft 21 so that it can move freely in the direction of its axis and rotate freely around its axis. The pair of support bushes 25 supporting the revolving camshaft 21 are fixed near the side of the grinding head 3 (see FIG. 1) by bush holders which are support members 26.

[0052] An arm member 27 is provided near the lower end of the revolving camshaft 21, and a detection sensor 10 is provided near the tip of the arm member 27 away from the revolving camshaft 21. This allows the detection sensor 10 to freely rotate around the axis of the revolving camshaft 21.

[0053] An air cylinder 30 is provided above the revolving camshaft 21, which uses air pressure to move the revolving camshaft 21 in the Y direction. The air cylinder 30 is a double-acting air cylinder that uses air pressure to move a piston rod 31 up and down. The vicinity of the lower end of the piston rod 31 fitted inside the air cylinder 30 is rotatably connected to the vicinity of the upper end of the revolving camshaft 21 via a floating rotary join.

[0054] The air cylinder 30 is fixed to the wheel spindle head 3 via a support 33, a support pillar 34, a support member 26, etc. That is, a plurality of support pillars 34 extending in the vertical direction, i.e., the Y direction, along the swivel cam shaft 21 are provided on the upper part of the support member 26, and a support 33 supporting the air cylinder 30 is fixed near the upper end of the support pillars 34.

[0055] An air supply device (not shown) is connected to the air cylinder 30 via an air pipe 32. The air supply device pressurizes or depressurizes the inside of the air cylinder 30 to send air to the inside of the air cylinder 30, which serves as a driving source for moving the piston rod 31 up and down.

[0056] The driving means for moving the detection sensor 10 of the sensor support mechanism 20 up and down is not limited to the air cylinder 30. The driving means of the sensor support mechanism 20 may be other driving means such as a hydraulic cylinder driven by hydraulic pressure, or an electric actuator having a motor, a ball screw, etc. and driven by electricity.

[0057] A cam follower 28 having a roller 29 that movably supports the revolving cam shaft 21 is provided near the upper portion of the support member 26. A cam groove 22 into which the roller 29 is fitted is formed on the outer periphery of the revolving cam shaft 21.

[0058] The cam followers 28 are provided in pairs facing each other with the revolving camshaft 21 at the center. A pair of cam grooves 22 are formed on the outer periphery of the revolving camshaft 21 to correspond to the pair of cam followers 28. That is, the cam grooves 22 are formed on both sides of the outer periphery of the revolving camshaft 21 so that their positions are approximately 180 degrees opposite each other on the outer periphery.

[0059] The cam follower 28 is fixed to the wheel spindle head 3 via the support member 26. Therefore, the cam follower 28 does not move relative to the wheel spindle head 3. The revolving cam shaft 21 moves while being supported by the roller 29 of the cam follower 28 fitted in the cam groove 22. That is, the revolving cam shaft 21 moves so that the roller 29, which is in a predetermined fixed position, follows the cam groove 22.

[0060] A protective cover 35 may be provided near the outer side of the support 34 to cover the support 34 and the revolving camshaft 21. This makes it possible to prevent grinding chips and the like from adhering to the cam groove 22 of the revolving camshaft 21.

[0061] FIG. 5 is a diagram showing the vicinity of the cam groove 22 of the sensor support mechanism 20. As shown in FIG. 5, a linear groove portion 23 extending in the axial direction, i.e., the Y direction, is formed in the cam groove 22 formed on the outer periphery of the revolving camshaft 21. Further, in the vicinity of the upper end of the revolving camshaft 21, a revolving groove portion 24 inclined in the oblique circumferential direction is formed in the cam groove 22. That is, the revolving groove portion 24 is formed in a substantially spiral shape on the outer periphery of the revolving camshaft 21.

[0062] 4 and 5, when the rollers 29 of the cam followers 28 move while supporting the linear motion groove portion 23, the swivel cam shaft 21 moves linearly in the Y direction. On the other hand, when the rollers 29 of the cam followers 28 move while supporting the swivel groove portion 24, the swivel cam shaft 21 moves in the Y direction while revolving, guided by the rollers 29 and the cam groove 22. That is, the swivel cam shaft 21 moves in the Y direction while revolving in a substantially spiral shape.

[0063] With this configuration, the sensor support mechanism 20 can suitably move the detection sensor 10 from a retracted position 13 away from the workpiece W where the workpiece W is not measured, to a detection position 14 where the workpiece W is measured, or in the reverse direction.

[0064] The cam followers 28 are provided in pairs facing each other with the revolving cam shaft 21 at the center. A pair of cam grooves 22 are formed on the outer periphery of the revolving cam shaft 21 to correspond to the pair of cam followers 28. This enables linear revolving feed of the detection sensor 10 with high accuracy and high efficiency.

[0065] Next, the process in which the detection sensor 10 moves from the retracted position 13 to the detection position 14 will be described in detail with reference to FIGS. Fig. 6(A) is a plan view showing a state in which the detection sensor 10 is in the retracted position 13. Fig. 6(B) is a side view showing a state in which the detection sensor 10 is in the retracted position 13.

[0066] 6(A) and 6(B), in the retracted state, the detection sensor 10 is at a retracted position 13 separated upward from the holding surface of the work table 4 and separated rearward from the grinding wheel 2.

[0067] Fig. 7(A) is a plan view showing a state in which the detection sensor 10 is being fed, and Fig. 7(B) is a side view showing a state in which the detection sensor 10 of the surface grinding device 1 is being fed. 7(A) and 7(B), when detecting the workpiece W, the detection sensor 10 moves from the retracted position 13 to approach the holding surface of the worktable 4, i.e., to approach the workpiece W.

[0068] Specifically, the air pressure supplied to the air cylinder 30 is used as a power source to push the turning cam shaft 21 downward by the air cylinder 30, and the detection sensor 10 moves downward together with the turning cam shaft 21 and the arm member 27.

[0069] At this time, the revolving camshaft 21 moves in a substantially linear manner from above to below along the axis, since the linear groove portion 23 of the cam groove 22 extending linearly along the axis is guided by the roller 29 of the cam follower 28. Therefore, the detection sensor 10 held near the tip of the arm member 27 also moves in a substantially linear manner from above to below along the revolving camshaft 21.

[0070] Fig. 8(A) is a plan view showing a state in which the detection sensor 10 is at the detection position 14. Fig. 8(B) is a side view showing a state in which the detection sensor 10 is at the detection position 14. Referring to Figures 8(A) and 8(B), when the rotating cam shaft 21 descends and the rotating groove portion 24 of the cam groove 22 reaches the roller 29 of the cam follower 28, the spirally formed rotating groove portion 24 is guided by the roller 29.

[0071] Then, the revolving camshaft 21 moves downward while revolving in a spiral manner, with the revolving groove portion 24 of the cam groove 22 being guided by the roller 29 of the cam follower 28. The arm member 27 provided near the lower end of the revolving camshaft 21 moves downward while revolving around the axis of the revolving camshaft 21. Therefore, the detection sensor 10 provided near the tip of the arm member 27 moves downward in a spiral manner while revolving around the revolving camshaft 21.

[0072] Then, the detection sensor 10 approaches the grinding wheel 2 while further approaching the holding surface of the work table 4. More specifically, the detection sensor 10 swings down and approaches the point at which the workpiece W is ground by the grinding wheel 2.

[0073] In this manner, the detection sensor 10 moves linearly downward and approaches the workpiece W, and then rotates about the rotating cam shaft 21 to approach the grinding point of the workpiece W. Then, the detection sensor 10 approaches the grinding wheel 2 and detects the processed surface of the workpiece W in the vicinity of the grinding point. This allows for highly accurate measurement with small error.

[0074] In this way, in the surface grinding apparatus 1 according to this embodiment, the detection sensor 10 is moved with high precision and efficiency using air pressure, and highly accurate measurements are performed by the detection sensor 10 near the grinding point of the workpiece W.

[0075] For example, a detection sensor 10 such as a touch probe can detect with high accuracy the processed surface of the workpiece W. From the highly accurate detection result by the detection sensor 10, a calculation means (not shown) accurately calculates the amount of grinding allowance of the workpiece W.

[0076] The sensor mechanism 5 according to this embodiment can also be used as a means for accurately checking the surface shape of the workpiece W. For example, measurement by the detection sensor 10 such as a touch probe may be used in a machining method for performing numerically controlled machining of the workpiece W using CAD data.

[0077] Specifically, a measurement path for the machined surface of the workpiece W may be generated using CAD data, the shape of the machined surface may be measured along the measurement path by the detection sensor 10 to obtain point cloud data, and shape data for the machined surface may be generated from the point cloud data. Then, a machining path may be calculated based on the obtained high-precision shape data for the machined surface of the workpiece W, and machining of the workpiece W may be performed by a machining program that moves the grinding wheel 2 and the workpiece W relatively along the machining path.

[0078] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0079] 1 Surface grinding equipment 2 Grinding wheels 3 Grinding head 4 Worktable 5 Sensor mechanism 10 Detection sensor 11 Probe 12 Contact 13 Evacuation position 14 Detection position 15 Saddle 16 Grinding wheel cover 20 Sensor support mechanism 21 Swivel cam shaft 22 Cam groove 23 Linear groove 24 Turning groove 25 Support bush 26 Support member 27 Arm parts 28 Cam follower 29 Laura 30 Air Cylinder 31 Piston rod 32 Air piping 33 Supports 34 Post 35 Protective cover Double work

Claims

1. A work table for holding a workpiece; a grinding wheel for grinding the workpiece held on the work table while rotating the workpiece; a grinding wheel head provided with a wheel shaft supporting the grinding wheel; A detection sensor for detecting the position of the processed surface of the workpiece; a sensor support mechanism that is provided on the wheel head and movably supports the detection sensor; The sensor support mechanism includes a revolving cam shaft extending toward a holding surface of the work table that holds the workpiece, the revolving cam shaft being reciprocable in a direction of an axis and rotatable about the axis; an arm member that is provided on the rotating cam shaft and supports the detection sensor at a position radially offset from the axis of the rotating cam shaft, The surface grinding device is characterized in that the detection sensor moves in a direction along the axis, rotates around the axis to approach and move away from the work table, and detects the workpiece surface at a position close to the grinding wheel by rotating around the axis.

2. The sensor support mechanism includes a drive means for moving the rotating cam shaft in the direction of the axis of the rotating cam shaft; a cam follower having a roller for movably supporting the rotating cam shaft; a cam groove formed on the rotating cam shaft, the roller being fitted into the cam groove and supported by the cam follower; 2. The surface grinding device according to claim 1, wherein the cam groove extends in the direction of the axis and is inclined obliquely in the circumferential direction near an upper end thereof.

3. 3. The surface grinding apparatus according to claim 2, wherein the driving means is an air cylinder having a piston rod connected to the swivel cam shaft for driving the swivel cam shaft.

4. The cam followers are provided in a pair to face each other about the rotating cam shaft, 4. The surface grinding device according to claim 2, wherein a pair of said cam grooves are formed on an outer periphery of said swivel cam shaft so as to correspond to said cam followers.

5. 5. The surface grinding apparatus according to claim 1, wherein the detection sensor is a touch probe that detects the position of the workpiece by contacting the workpiece surface.

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