JP5513050B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus, and more particularly to a grinding apparatus that rotates a metal bond grindstone to grind a workpiece and electrolytically dresses the metal bond grindstone.

  For example, there is an electrolytic in-process dressing grinding method (hereinafter referred to as “ELID grinding method”) as a grinding method that enables mirror surface grinding for ultra-precise grinding of iron-based materials. This ELID grinding method uses a metal bond grindstone in which fine abrasive grains are bonded by a conductive bond material such as cast iron, and electrolytically dresses the metal bond grindstone during grinding. The electrode for electrolytic dressing is disposed opposite to the ground surface with a slight gap, and the metal bond grindstone and electrode are supplied while supplying a grinding fluid having conductivity such as aqueous coolant between the metal bond grindstone and the electrode for electrolytic dressing. In between, electrolytic dressing is performed to remove only the bonding material on the surface of the grindstone and expose the cutting edges of the abrasive grains.

  As an example of this ELID grinding method, an outline of a grinding apparatus disclosed in Patent Document 1 will be described with reference to FIG. This grinding apparatus 101 is disposed opposite to a metal bond grindstone 103 fixed to the tip of a rotating shaft 102 serving as a main shaft, an end surface 103a serving as a grinding surface of the metal bond grindstone 103, and an outer peripheral surface 103b via a slight gap. The electrode plates 104 and 105, the brush 106 that is in sliding contact with the outer peripheral surface 103c of the main body of the metal bond grindstone 103, and the gaps between the end surfaces 103a and the outer peripheral surface 103b of the metal bond grindstone 103 and the electrode plates 104 and 105 are electrically conductive. A nozzle 107 for supplying a grinding fluid such as aqueous coolant, a positive electrode is connected to the brush 106, and a negative electrode is connected to the electrode plates 104, 105, and the end surface 103 a and the outer peripheral surface 103 b of the metal bond grindstone 103 and the electrode plate 104 , 105 is provided with a power supply 108 energized with a grinding liquid interposed therebetween.

  On the other hand, the work W is fixed to the support means 109, and the end surface 103a of the metal bond grindstone 103 is pressed against the work W while the metal bond grindstone 103 is rotated by the rotating shaft 102. , 105 is supplied with a grinding fluid and energized by a power source 108. Although the metal bond grindstone 103 is clogged and worn as the workpiece W is ground, it is electrolytically dressed by the grinding liquid and the electrode plates 104 and 105. Thus, the workpiece W can be continuously ground by the dressed metal bond grindstone 103.

Japanese Patent Laid-Open No. 10-76448

  According to the grinding apparatus described in Patent Document 1, the metal bond grindstone 103 is electrolytically dressed during the grinding process, and the workpiece W can be continuously ground by the dressed metal bond grindstone 103. In other words, the grinding liquid exists between the electrode plates 104 and 105 and the metal bond grindstone 103 during the grinding of the workpiece W, and the electrode plates 104 and 105 are energized between the electrode plates 104 and 105 and the metal bond grindstone 103. Electrolysis is performed in which the metal bond grindstone 103 becomes the anode.

  The electrolytic dressing and wear of the metal bond grindstone 103 performed during grinding of the workpiece W gradually increase the gaps between the end surface 103a and the outer peripheral surface 103b of the metal bond grindstone 103 and the electrodes 104 and 105, thereby reducing the efficiency of the electrolytic dressing. In addition, there is a concern that the dressing effect is reduced and the quality of the workpiece W that has been ground is reduced.

  Accordingly, an object of the present invention made in view of such a point is to maintain a stable electrolytic dressing efficiency by maintaining a gap between a metal bond grindstone and an electrode in an appropriate range, and to ensure high-quality grinding. To provide an apparatus.

The grinding apparatus according to the first aspect of the present invention for solving the above-described problem is grinding in which a cylindrical metal bond grindstone in which abrasive grains are bonded by a conductive bond material is rotated by an electric motor to grind the workpiece. A dressing device comprising an electrolytic dressing electrode facing the electrode surface with an interval through which the grinding liquid is interposed and an outer peripheral surface of the metal bond grindstone, and the metal bond grindstone and the electrode for electrode dressing Power supply to energize the metal bond grindstone and the electrode for electrolytic dressing with the grinding fluid interposed between them, and the metal bond grindstone rotating in the presence of the grind fluid and the electrode for electrolytic dressing are energized to electrolytic dressing in grinding apparatus which swings the dressing device around the parallel axial and rotational center axis of the metal bond grindstone The downstream end of the metal bonded grinding wheel rotation direction of the electrode surface is moved closer to the outer peripheral surface of the metal bond wheel comprising a moving device for adjusting the gap between the outer peripheral surface and the electrode surface of the electrolytic dressing electrode of metal bond grindstone, Tokoro life The dressing device is moved by the moving device in the direction in which the electrode for electrolytic dressing of the dressing device approaches the outer peripheral surface of the metal bond grindstone based on the estimated threshold value for obtaining the workpiece grinding quality of The gap with the electrode surface of the dressing electrode is adjusted to a desired interval.

  According to this, based on the estimated threshold value set so that the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrode for electrolytic dressing obtains the desired workpiece grinding quality, the dressing device is moved to the electrode surface by the moving device. Moves in a direction approaching the outer peripheral surface of the metal bond grindstone to adjust the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrolytic dressing electrode. The gap with the electrode surface is well maintained, stable electrolytic dressing efficiency can be maintained, and the warp is ground by a metal bond grindstone that is always well dressed to ensure high quality grinding.

In addition, the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface is adjusted narrowly on the downstream side in the rotation direction of the metal grindstone in the electrolytic dressing region formed between the outer peripheral surface of the opposing metal bond grindstone and the electrode surface. Thus, the discharge of the grinding liquid that rotates around the outer peripheral surface of the meta-ribbonized grinding wheel from the gap between the electrode surface and the outer peripheral surface of the metal bond grindstone is suppressed, and the gap between the opposing electrode surface and the outer peripheral surface of the metal bond grindstone is reduced. The grinding liquid is sufficiently retained and held in the electrolytic dressing region, and a uniform electrolytic dressing can be applied to the outer peripheral surface of the metal bond grindstone.

According to a second aspect of the invention, the grinding device according to claim 1, the estimated threshold value, characterized in that it is a grinding number of workpiece by a preset metal bond grinding wheel.

  According to this, every time the cutting of the workpiece with the metal bond grindstone reaches a preset number of cutting operations, the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrolytic dressing electrode is adjusted to the desired gap, The gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrode for electrolytic dressing is maintained well, stable electrolytic dressing efficiency is obtained, and the workpiece is ground by the metal bond grindstone that is always well dressed, resulting in high quality Grinding can be secured.

According to a third aspect of the invention, the grinding device according to claim 1, the estimated threshold value, characterized in that it is a major axis current value as the drive power of the electric motor set in advance.

  According to this, every time the spindle current value of the electric motor reaches a preset estimated threshold value due to increased grinding resistance in workpiece cutting with the metal bond grindstone due to wear of the metal bond grindstone or electrolytic dressing, etc. The gap between the electrode surface of the electrode and the outer peripheral surface of the metal bond grindstone is adjusted to the desired gap, and the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrode for electrolytic dressing is adjusted to the desired gap and stable The workpiece is ground by a metal bond grindstone that is always well dressed while maintaining the electrolytic dressing efficiency, and high quality grinding can be ensured.

According to a fourth aspect of the invention, the grinding device according to claim 1, said estimated threshold is the electrolytic current value of the grinding fluid interposed between the electrode surface facing the outer peripheral surface of the metal bond grindstone It is characterized by that.

  According to this, the wear of the metal bond grindstone increases the gap between the metal bond grindstone and the electrode surface of the dressing electrode, and the electrolytic current of the grinding fluid interposed between the metal bond grindstone and the electrode surface of the dressing electrode decreases. Each time the electrolytic current value reaches a preset estimation threshold, the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrode for electrolytic dressing is adjusted to the desired gap, and stable electrolytic dressing efficiency is maintained. The workpiece is ground by a metal bond grindstone that is always dressed well and high quality grinding can be ensured.

The invention described in claim 5 is the grinding apparatus according to claim 1, the estimated threshold value, characterized in that it is set by the outside diameter of the metal bond grindstone wear.

  According to this, every time the diameter of the metal bond grindstone in the machining of the workpiece by metal bond reaches a preset estimated threshold, the gap between the electrode surface of the electrode for electrolytic dressing and the outer peripheral surface of the metal bond grindstone is set to the desired value. The workpiece is ground by a metal bond grindstone that is adjusted to the gap of the gap and maintains stable electrolytic dressing efficiency and is always dressed well, and high-quality grinding can be ensured.

  According to the present invention, the gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrode for electrolytic dressing is based on the estimated threshold value for obtaining the desired workpiece grinding quality. Stable electrolytic dressing efficiency is maintained by adjusting the gap with the electrode surface and maintaining a good gap between the outer peripheral surface of the metal bond grindstone and the electrode surface of the electrode for electrolytic dressing. The workpiece is ground by the grindstone to ensure high quality grinding.

It is a figure which shows the outline | summary of the grinding processing apparatus which concerns on 1st Embodiment. It is the A section enlarged view of FIG. FIG. 3 is a view taken in the direction of arrow B in FIG. It is an operation | movement flowchart of a grinding processing apparatus. It is a figure which shows the outline | summary of the grinding-work apparatus which concerns on 2nd Embodiment. It is a correlation diagram of a spindle current and grinding. It is an operation | movement flowchart of a grinding processing apparatus. It is a figure which shows the outline | summary of the grinding-work apparatus which concerns on 3rd Embodiment. It is an operation | movement flowchart of a grinding processing apparatus. It is a block diagram which shows the circuit structure of the principal part of the grinding-work apparatus which concerns on 4th Embodiment. It is an operation | movement flowchart of a grinding processing apparatus. It is a figure which shows the outline | summary of the grinding-work apparatus which concerns on a reference example . It is the C section enlarged view of FIG. It is an operation | movement flowchart of a grinding processing apparatus. It is explanatory drawing of the conventional grinding processing apparatus.

(First embodiment)
The first embodiment according to the present invention will be described with reference to FIGS. 1 to 4 by taking as an example the case of grinding the outer peripheral surface of a shaft-shaped workpiece W. FIG.

  FIG. 1 is a diagram showing an outline of a grinding apparatus, FIG. 2 is an enlarged view of a portion A in FIG. 1, and FIG. 3 is a view taken in the direction of arrow B in FIG. Note that the side panels are not shown in FIGS. 1 and 2 in order to clarify the configuration of the grinding apparatus. Moreover, in FIG. 3, a metal bond grindstone is illustrated with a virtual line. An arrow R indicates the rotation direction of the metal bond grindstone.

  The grinding apparatus 1 is supported by an apparatus main body such as a frame (not shown) and is mounted on a main shaft 4 that is rotationally driven by an electric motor (not shown). The apparatus main body is parallel to the rotation center axis 4a of the main shaft 4. A dressing device 10 that is swingably supported by a support shaft 9 having a shaft core 9 a extending in the direction of movement, a moving device 50 that moves and adjusts the dressing device 10 in a direction in which the dressing device 10 contacts and separates from the metal bond grindstone 5, and a work W. A work holding mechanism (not shown) that freely holds is provided, and the rotation center axis 4a of the main shaft 4, the axis 9a of the support shaft 9, and the work W are arranged on the same axis. For the sake of explanation, this axis is referred to as a reference line L. The state indicated by the solid line in FIGS. 1 and 2 in which the center of the electrode 35 of the electrode 31 for electrolytic dressing is located on the reference line L is referred to as a reference position.

  The metal bond grindstone 5 attached to the main shaft 4 is made of a conductive bond material made of bronze or cast iron with fine abrasive grains such as diamond, CBN (cubic boron nitride), crystalline aluminum oxide, and silicon carbide. It is formed by coupling and is formed in a columnar shape having end faces 6 and 7 and an outer peripheral surface 8 serving as a grinding surface.

  The dressing apparatus 10 will be described. In the description of the dressing apparatus 10, the state where the dressing apparatus 10 is in the reference position will be described for convenience.

  The dressing device 10 includes a base portion 11 that is swingably supported by a support shaft 9, an electrode holder 20 that is attached to and supported by the base portion 11, an electrode 31 for electrolytic dressing that is slidably received and held in the electrode holder 20, An electrode position adjusting unit 40 is provided.

  The base portion 11 includes a rectangular tip surface 12 that extends vertically perpendicular to the reference line L, an upper surface 13 and a lower surface 14 that extend in the direction of the reference line L from the upper and lower ends of the tip surface 12, and an upper surface 13 and a lower surface. 14 is a rectangular plate having a rear surface 15 and a side surface 16 extending up and down between the rear ends, and a front end portion in the vicinity of the front end surface 12 is swingably supported by a support shaft 9 on the apparatus body.

  The electrode holder 20 includes an electrode holder main body 21 and a side panel 29 formed of an insulating member. In FIG. 1, the side panel 29 is not shown.

  The electrode holder main body 21 includes a bottom portion 22 having a rectangular bottom surface 22 a extending along the base portion 11, an upper portion 23 extending in parallel with the reference line L along the upper edge of the bottom portion 22, and a bottom portion 22. A lower portion 24 extending parallel to the reference line L along the edge and a rear portion 25 extending along the rear edge of the bottom portion 22 and connecting the upper portion 22 and the lower portion 24 are integrally formed, and the top surface 26 is formed. It is formed in a planar shape that is continuous in a U-shape.

  The tip portion 27 of the electrode holder main body 21 includes a rectangular flat upper tip surface portion 27a and a lower tip surface portion 27b formed by the upper portion 23 and the lower portion 24, and a concave portion formed on the bottom portion 22 so that the upper tip surface portion 27a and the lower portion are formed. It is formed by a first side tip surface 27c that connects the tip surface portion 27b.

  Furthermore, an electrode housing portion 28 that opens in a U-shape at the distal end portion 27 of the electrode holder body 21 and extends in the direction of the reference line L and opens in a rectangular shape at the top portion 26 is configured.

  The electrode accommodating portion 28 is a rectangular flat surface formed along the upper edge of the first side guide surface 28a continuously to the first side guide surface 28a formed on the bottom portion 22 in a rectangular flat shape and the upper tip surface portion 27a. A U-shaped cross-section continuous to the reference line L direction by a rectangular planar lower surface guide surface 28c formed along the lower edge of the first side guide surface 28a while continuing to the upper guide surface 28b and the lower tip surface portion 27b. The rear ends of the first side guide surface 28a, the upper guide surface 28b, and the lower guide surface 28c are connected by a rear guide surface 28d. A rod through groove 25b, a grinding fluid supply pipe insertion hole 25c, and a wire hole 25e are formed in the rear portion 25 so as to extend in the direction of the reference line L and communicate the rear surface 25a and the rear guide surface 28d.

  On the other hand, the side panel 29 is formed in a flat plate shape covering the top surface 26 of the electrode holder main body 21, and is formed with a second side guide surface 28e facing the first side guide surface 28a.

  The electrode holder main body 21 thus formed is positioned on the distal end side of the base portion 27 so that the bottom surface 22a is in contact with the side surface 16 of the base portion 11 and the distal end surface 27 is continuous with the distal end surface 12 of the base portion 11. In this state, it is coupled to the base portion 11 by bolts. A side panel 29 is superimposed on the top surface 26 of the electrode holder main body 21 and is coupled by bolts.

  The electrode 31 for electrolytic dressing is made of, for example, iron having excellent conductivity, and includes a first side guide surface 28a, an upper guide surface 28b, a lower guide surface 28c, and a side panel of the electrode housing portion 28 formed in the electrode holder 20. 29 has a rectangular cross-sectional shape having a first side surface 31a, an upper surface 31b, a lower surface 31c, and a second side surface 31e that can be slidably contacted with a second side guide surface 28e formed by the inner surface of the first side surface 31e. A rear end portion 33 and a front end portion 34 are divided by a rectangular opening 32 penetrating the side surface 31e.

  The rear end portion 33 includes a rod through groove 25b formed in the rear portion 25 of the electrode holder body 21, a grinding fluid supply pipe insertion hole 25c, and a rod locking groove 33b and a grinding fluid supply pipe insertion hole 33c corresponding to the electric wire hole 25e. A wire groove 33e is formed.

  An electrode surface 35 having a circular arc cross section is formed on the distal end surface of the distal end portion 34. The electrode surface 35 has a rectangular shape that is long in the vertical direction so as to face the outer peripheral surface 8 of the metal bond grindstone 5, and an intended gap that allows the grinding liquid to intervene between the outer peripheral surface 8 of the metal bond grindstone 5, for example, It is formed in a cylindrical inner peripheral surface in which about 0.5 to 5 mm is formed.

  The front end portion 34 is formed with a grinding fluid passage 36 having a grinding fluid supply port 36a corresponding to the grinding fluid supply tube insertion hole 35c formed in the rear end portion 33, and is branched from the grinding fluid passage 36 to form an electrode. A discharge hole opening in the surface 35 is formed. In the present embodiment, as shown in FIG. 3, a discharge hole 37 is opened on the upstream end 35 a side of the electrode surface 35 on the upstream side in the rotation direction of the metal bond grindstone 5.

  The electrode position adjustment unit 40 is attached to the apparatus main body and has an adjustment base 41 formed with a rod through hole (not shown), a rod through groove 25b of the electrode holder main body 21, and a stepped portion and a screw portion formed at the tip 42a. And a pair of adjustment nuts that are screwed oppositely to the base end portion 42b of the rod 42 that passes through the rod through hole of the adjustment base portion 41 via the adjustment base portion 41. 43a and 43b, and a pair of flanged bushes 44a and nuts 44b and the like fitted to a rod locking groove 33b formed on the tip 42a of the rod 42 and the rear end 33 of the electrode 31. The fixing tool 44 to fix is provided. The electrode 31 for electrolytic dressing is fixed by fixing the base end 42b of the rod 42 to the adjustment base 41 by a pair of adjustment nuts 43a and 43b screwed to the base end 42b of the rod 42, and the adjustment nuts 43a and 43b are loosened. By moving the rod 42 in the axial direction, the electrode 31 for electrolytic dressing moves in the electrode accommodating portion 28 between a forward position where the electrode 31 for electrolytic dressing approaches the metal bond grindstone 5 and a backward position where the electrode is separated.

  A grinding liquid supply pipe 38 for supplying a grinding liquid from a grinding liquid supply source (not shown) is formed in a grinding liquid supply pipe insertion hole 25c formed in the electrode holder body 21 and a rear end portion 33 of the electrode 31 for electrolytic dressing. The outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrolytic dressing electrode 31 which are movably penetrated through the grinding fluid supply pipe insertion hole 33c and connected to the grinding fluid supply port 36a and face the grinding fluid from the grinding fluid supply source. A grinding fluid supply means for supplying to the electrolytic dressing region formed between the two is formed.

  In addition, the positive electrode is connected to the metal bond grindstone 5 via the apparatus main body and the main shaft 4, and the negative electrode is connected to the electric wire 39 penetrating the electric wire groove 33 de formed in the rear end portion 33 of the electrolytic dressing electrode 31. And a power source that is connected to the tip 34 of the electrode 31 for electrolytic dressing and energizes between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 via a grinding fluid.

  The moving device 50 has an actuator 51 that raises or lowers the rear portion of the base portion 11 to swing the base portion 11 in the vertical direction about the axis 9a of the support shaft 9. The actuator 51 is, for example, an electric motor. 52 and a transmission mechanism 53 such as a feed screw mechanism that is installed between the electric motor 52 and the rear end portion of the base portion 11 and moves up and down the rear portion of the base portion 11 by the electric motor 52. Furthermore, the moving device 50 is configured so that the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31 is based on an estimated threshold value set so as to obtain a desired workpiece grinding quality. A control device 54 for controlling the operation is provided.

  Here, the outer peripheral surface 8 which becomes the grinding surface of the metal bond grindstone 5 gradually decreases by grinding and electrolytic dressing, for example, as shown by the imaginary line 8a in FIGS. 1 and 2, and the outer peripheral surface 8 of the metal bond grindstone 5 and the metal The gap with the outer peripheral surface 8 of the bond grindstone 5 gradually increases from the intended gap. Since the increase in the gap with the outer peripheral surface 8 of the metal bond grindstone 5 greatly depends on the number of times of grinding of the workpiece W, when the grinding of the workpiece W reaches a preset number of times of grinding, the actuator 51 is connected to the metal bond. It is estimated that the gap between the outer peripheral surface 8 of the grindstone 5 and the electrode surface 35 of the electrode 31 for electrolytic dressing has reached the threshold of the limit for obtaining good workpiece grinding by the outer peripheral surface 8 of the metal bond grindstone 5. The dressing device 10 is operated to swing from the reference position about the axis 9a of the support shaft 9 as shown by the imaginary line 10a in FIGS. 1 and 2, and the outer peripheral surface 8 of the opposing metal bond grindstone 5 is electrolyzed. The gap between the downstream end 35 b of the electrode surface 35 that is the downstream end of the electrolytic dressing region formed between the electrode surface 35 of the dressing electrode 31 and the outer peripheral surface 8 of the metal bond grindstone 5. Adjust so that the desired gap.

  For this reason, the control device 54 includes a grinding process count unit 54a that counts the number of times the workpiece W is ground, and the cutting process that is counted by the grinding process count unit 54 and a preset estimated threshold value. The number of times is compared, and each time the grinding work of the workpiece W reaches a preset number of grinding times, the actuator 51 is operated to swing the dressing device 10 about the shaft core 9a of the support shaft 9 to The gap with the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap.

  The dressing apparatus 10 is swung in the direction in which the downstream end 35b side of the electrode surface 35 approaches the outer peripheral surface 8 of the metal bond grindstone 5 around the shaft core 9a of the support shaft 9. The downstream end 8b, which is the downstream end in the rotation direction of the metal bond grindstone 5, moves closer to the outer peripheral surface 8 of the metal bond grindstone 5, and is formed between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 facing each other. The gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the downstream end 8b of the electrode surface 35 is adjusted narrowly on the downstream side in the rotation direction of the metal grindstone 5 in the dressing region. Thereby, the discharge of the grinding liquid that rotates around the outer peripheral surface 8 of the meta-ribbonized grinding stone 5 from the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the downstream end 8b of the electrode 8 is suppressed, and the opposing electrode surface 35 and The grinding fluid is sufficiently retained and retained in the electrolytic dressing region between the outer peripheral surface 8 of the metal bond grindstone 5 and uniform electrolytic dressing is applied to the outer peripheral surface 8 of the metal bond grindstone 5.

  It should be noted that the number of cutting operations serving as the estimated threshold can be easily set based on experiments or simulations.

  Next, the operation control of the cutting apparatus 1 will be described below based on the operation flowchart of FIG.

  In FIG. 1, before starting the grinding process with the metal bond grindstone 5, the adjustment nuts 43a and 43b of the electrode position adjusting unit 40 are loosened and the rod 42 is moved in the axial direction to move the electrode 31 for electrolytic dressing, The electrode surface 35 of the electrode 31 for electrolytic dressing is opposed to the outer peripheral surface 8 of the metal bond grindstone 5 with a predetermined interval. Then, the adjustment nuts 33a and 33b are tightened to fix the rod 32, and the electrolytic dressing electrode 31 is fixed to the position for preparation.

  The workpiece W is set in the workpiece holding mechanism of the grinding apparatus 1 (step S111). Grinding fluid is supplied from the grinding fluid supply source to the grinding fluid path 26 of the electrode 31 for electrolytic dressing through the grinding fluid supply pipe 38, and the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 from the discharge hole 37. While supplying the grinding fluid to the electrolytic dressing area between, the power is turned on. The current output from the power source flows through the main body of the apparatus, the main shaft 4, the metal bond grindstone 5, the grinding fluid, the electrode 31 for electrolytic dressing, the electric wire 39, and the path of the power source, and the electrolytic dressing of the metal bond grindstone 5 is started. In this state, the spindle 2 is driven at a predetermined rotational speed, the metal bond grindstone 5 is rotated, and the workpiece W is rotated to start grinding (step S112).

  The outer peripheral surface 8 which becomes the grinding surface of the metal bond grindstone 5 clogged due to the grinding of the workpiece W is electrolytically dressed by the grinding liquid interposed between the opposed outer peripheral surface 8 and the electrode surface 35 and clogged. It will be resolved. That is, a conductive grinding fluid exists between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5 during the cutting of the workpiece W, and between the electrode 31 and the metal bond grindstone 5. When energized, the electrode 31 for electrolytic dressing becomes a cathode and the metal bond grindstone 5 becomes an anode, and the outer peripheral surface 8 of the metal bond grindstone 5 is electrolytic dressed.

  It is determined whether or not the grinding has reached a predetermined number of times of grinding that is a preset estimation threshold (step S113).

  If it is determined that the predetermined number of grinding operations has been reached (YES in step S113), then the grinding processing ends (step S114).

  In a state where the grinding process is completed and the rotation of the metal bond grindstone 5 is stopped, the actuator 51 is operated to move the dressing device 10 around the axis 9a of the support shaft 9 to the virtual line 10a in FIGS. The gap between the downstream end 35b of the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap by swinging in the direction shown (step S115).

  Next, the workpiece W for which grinding has been completed is removed from the workpiece holding mechanism and carried out (step S116).

  On the other hand, if it is determined in step S113 that the grinding process has not reached the predetermined number of grinding processes set in advance (NO), then the grinding process ends (step S117), and the workpiece W is removed from the workpiece holding mechanism. It removes and carries out (step S116).

  Therefore, every time the workpiece W is cut by the metal bond grindstone 5 reaches a preset number of times of cutting, the actuator 51 is operated to swing the dressing device 10 around the support shaft 9 and face the metal bond grindstone. 5 is a gap between the downstream end 35b of the electrode surface 35 which is the downstream end of the electrolytic dressing region formed between the outer peripheral surface 8 of the electrolytic dressing electrode 31 and the outer peripheral surface 8 of the metal bond grindstone 5. Stable electrolytic dressing efficiency is maintained by maintaining the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode 13 for electrolytic dressing in a good range, and the dressing is always good. The workpiece W is ground by the metal bond grindstone 5 thus made, and high quality grinding can be ensured.

(Second Embodiment)
A second embodiment of a grinding apparatus according to the present invention will be described with reference to FIGS. FIG. 5 is a diagram showing an outline of a grinding apparatus, FIG. 6 is a correlation diagram between spindle power and grinding, and FIG. 7 is a flowchart of the operation.

  The grinding apparatus 1 according to the present embodiment differs from the first embodiment in the movement control means 50, and the other configuration is the same as that of the first embodiment, and corresponds to FIGS. 1 and 2 in FIG. By attaching the same reference numerals to the portions, detailed description of the portions will be omitted, and different portions will be mainly described.

  The moving device 50 has an actuator 51 that raises or lowers the rear portion of the base portion 11 to swing the base portion 11 in the vertical direction about the axis 9a of the support shaft 9. The actuator 51 is, for example, an electric motor. 52 and a transmission mechanism 53 that is installed between the electric motor 52 and the rear end portion of the base portion 11 and moves up and down the rear portion of the base portion 11 by the electric motor 52. The moving device 50 further includes a control device 55 that controls the operation of the actuator 51 based on an estimated threshold value of the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31.

  Here, the outer peripheral surface 8 which becomes the grinding surface of the metal bond grindstone 5 gradually decreases due to wear due to grinding and electrolytic dressing, for example, as shown by a virtual line 8a in FIG. 5, and the outer peripheral surface 8 of the metal bond grindstone 5 and the metal bond The gap with the outer peripheral surface 8 of the grindstone 5 increases. When the gap with the outer peripheral surface 8 of the metal bond grindstone 5 is increased, the electrolytic dressing efficiency is gradually lowered, the dressing effect of the metal bond grindstone 5 is lowered, and the grinding resistance in the grinding process by the metal bond grindstone 5 is increased. The spindle current, which is the driving power of the electric motor that drives the spindle 4 to rotate, increases gradually. An example of the correlation between this grinding process and the spindle current is shown in FIG.

  When this spindle current value reaches a preset current value, that is, a set estimation threshold, the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31 is the expected metal bond grindstone. 5 is estimated to have reached a limit threshold value for obtaining workpiece grinding, and the actuator 51 is operated to move the dressing device 10 from the reference position to the axis 9a of the support shaft 9 in FIG. As shown by 10a, it swings to adjust the gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 to the desired gap. Therefore, the control device 55 includes a spindle current detection sensor 55a that detects a spindle current, compares the spindle current value detected by the spindle current detection sensor 55a with a preset spindle current value as an estimated threshold value, and detects the detected value. Each time the main shaft current value reaches the estimated threshold value, the actuator 51 is actuated to swing the dressing device 10 about the support shaft 9 to oppose the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrolytic dressing electrode 31. The gap between the downstream end 35b of the electrode surface 35 that is the downstream end of the electrolytic dressing region formed between the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap. Note that the spindle current value serving as the estimation threshold can be easily set based on experiments or simulations.

  Next, the operation control of the cutting apparatus 1 will be described below based on the operation flowchart of FIG.

  In FIG. 5, before starting the grinding with the metal bond grindstone 5, the electrode position adjusting unit 40 sets the desired gap between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5. Prepare to adjust.

  The workpiece W is set in the workpiece holding mechanism of the grinding apparatus 1 (step S121). The grinding fluid is supplied from the grinding fluid supply source to the electrolytic dressing region between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 from the discharge hole 37 through the grinding fluid supply pipe 38 and the like, while the power supply is turned on. throw into. The current output from the power source flows through the apparatus main body, the main shaft 4, the metal bond grindstone 5, the grinding fluid, the electrode 31 for electrolytic dressing, the electric wire 39, and the path of the power source, and the electrolytic dressing is started. In this state, the main shaft 2 is driven at a predetermined rotational speed, the metal bond grindstone 5 is rotated, and the workpiece W is rotated to start grinding (step S122).

  A conductive grinding fluid exists between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5 during the cutting of the workpiece W, and electricity is passed between the electrode 31 and the metal bond grindstone 5. Thus, the electrode 31 for electrolytic dressing becomes a cathode and the metal bond grindstone 5 becomes an anode, and the outer peripheral surface 8 of the metal bond grindstone 5 is electrolytically dressed.

  The spindle current value during the grinding process is detected, and it is determined whether or not the detected spindle current value is larger than a preset estimation threshold value (step S123).

  Then, when it is determined that the detected spindle current value is larger than the estimated threshold (YES in step S123), the grinding process is finished thereafter (step S124).

  In a state where the grinding process is completed and the rotation of the metal bond grindstone 5 is stopped, the actuator 51 is operated to move the dressing device 10 around the axis 9a of the support shaft 9 to the virtual line 10a in FIGS. By swinging in the direction shown, the gap between the downstream end 35b of the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to be the desired gap (step S125).

  Next, the workpiece W for which grinding has been completed is removed from the workpiece holding mechanism and carried out (step S126).

  On the other hand, if it is determined in step S123 that the spindle current value is smaller than the estimated threshold value (NO), then the grinding process ends (step S127), and the workpiece W is removed from the workpiece holding mechanism and carried out (step S126).

  Therefore, every time the spindle current value in the cutting of the workpiece W by the metal bond 5 reaches the preset estimated threshold value, the actuator 51 is actuated to swing the dressing device 10 about the support shaft 9 and the electrode surface 35. The gap between the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap, and the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode 31 for electrolytic dressing is maintained in an appropriate range. Stable electrolytic dressing efficiency is maintained, and the workpiece W is ground by the metal bond grindstone 5 that is always dressed satisfactorily, and high-quality grinding can be ensured.

(Third embodiment)
A third embodiment of the grinding apparatus according to the present invention will be described with reference to FIGS. FIG. 8 is a diagram showing an outline of the grinding apparatus, and FIG. 9 is an operation flowchart.

  The grinding apparatus 1 according to the present embodiment differs from the first embodiment in the movement control means 50, and the other configuration is the same as that of the first embodiment. FIG. 8 corresponds to FIG. 1 and FIG. By attaching the same reference numerals to the portions, detailed description of the portions will be omitted, and different portions will be mainly described.

  The moving device 50 includes an actuator 51 that raises or lowers the rear portion of the base portion 11 to swing the base portion 11 in the vertical direction around the support shaft 9. The actuator 51 includes, for example, an electric motor 52 and an electric motor. 52 and a rear end portion of the base portion 11, and a transmission mechanism 53 that moves up and down the rear portion of the base portion 11 by the electric motor 52. The moving device 50 further includes a control device 56 that controls the operation of the actuator 51 based on an estimated threshold value of the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31.

  Here, the outer peripheral surface 8 which becomes the grinding surface of the metal bond grindstone 5 gradually decreases by grinding and electrolytic dressing, for example, as shown by a virtual line 8a in FIG. 8, and the electrode surface 35 of the electrode 31 for electrolytic dressing and the metal bond grindstone 5 and the outer peripheral surface 8 increase. As the gap between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5 increases, the efficiency of electrolytic dressing gradually decreases, and the space between the electrode surface 35 and the outer peripheral surface 8 of the metal bond 5 gradually increases. The electrolytic current during the electrolytic dressing of the grinding liquid between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 increases and decreases.

  When the decreasing electrolytic current reaches a preset current value, the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31 is caused by the outer peripheral surface 8 of the intended metal bond grindstone 5. Estimating that the threshold value for obtaining the grinding process has been reached, the actuator 51 is actuated to swing the dressing device 10 from the reference position as shown by the phantom line 10a in FIG. The gap with the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap.

  Therefore, the control device 56 includes an electrolytic current detection sensor 56a that detects an electrolytic current of the grinding liquid between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31, and the electrolytic current detection sensor The electrolytic current value detected by 55a is compared with a preset electrolytic current value, that is, an estimated threshold value, and each time the detected electrolytic current value reaches the estimated threshold value, the actuator 51 is actuated so that the dressing apparatus 10 is supported by the support shaft 9. The gap between the downstream end 35b of the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap by swinging to the center. In addition, the electrolytic current value used as an estimation threshold value can be easily set based on experiment or simulation.

  Next, the operation control of the grinding apparatus 1 will be described below based on the operation flowchart of FIG.

  In FIG. 8, before starting the grinding with the metal bond grindstone 5, the electrode position adjustment unit 40 adjusts the electrode surface 35 of the electrode 31 for electrolytic dressing to the outer peripheral surface 8 of the metal bond grindstone 5 to the desired gap. Prepare.

  The workpiece W is set in the workpiece holding mechanism of the grinding apparatus 1 (step S131). The grinding fluid is supplied from the grinding fluid supply source to the electrolytic dressing region between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 from the discharge hole 37 through the grinding fluid supply pipe 38 and the like, while the power supply is turned on. throw into. The current output from the power source flows through the apparatus main body, the main shaft 4, the metal bond grindstone 5, the grinding fluid, the electrode 31 for electrolytic dressing, the electric wire 39, and the path of the power source, and the electrolytic dressing is started. In this state, the spindle 2 is driven at a predetermined rotation speed, the metal bond grindstone 5 is rotated, and the workpiece W is rotated to start grinding (step S132).

  Conductive grinding fluid exists between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5 during the cutting of the workpiece W, and energizes between the electrode 31 and the metal bond grindstone 5. Thus, the electrode 31 for electrolytic dressing becomes a cathode and the metal bond grindstone 5 becomes an anode, and the outer peripheral surface 8 of the metal bond grindstone 5 is electrolytically dressed.

  The electrolytic current value during the grinding process, that is, the electrolytic dressing is detected, and it is determined whether or not the detected electrolytic current value is small based on a preset estimation threshold value (step S133).

  If it is determined that the detected electrolytic current value is smaller than the estimated threshold value (YES in step S133), then the grinding process ends (step S134).

  In a state where the grinding process is finished and the rotation of the metal bond grindstone 5 is stopped, the actuator 51 is operated to move the dressing device 10 in the direction indicated by the imaginary line 10a in FIG. By swinging, the gap between the downstream end 35b of the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to a desired gap (step S135).

  Next, the workpiece W for which grinding has been completed is removed from the workpiece holding mechanism and carried out (step S136).

  On the other hand, when it is determined that the electrolytic current value detected in step S133 is larger than the estimated threshold value (NO), the grinding process is finished thereafter (step S137), and the workpiece W is removed from the workpiece holding mechanism and carried out (step S136). .

  Therefore, each time the electrolytic current value of the grinding fluid in the cutting of the workpiece W by the metal bond 5 reaches a preset estimated threshold value, the actuator 51 is operated to swing the dressing device 10 about the support shaft 9 to thereby move the electrode. The gap between the surface 35 and the downstream end 8b of the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to a desired gap, and the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode 13 for electrolytic dressing is good. By maintaining in an appropriate range, stable electrolytic dressing efficiency is maintained, and the workpiece W is ground by the metal bond grindstone 5 that is always dressed well, and high-quality grinding can be ensured.

(Fourth embodiment)
A fourth embodiment of a grinding apparatus according to the present invention will be described with reference to FIGS. FIG. 10 is a diagram showing an outline of the grinding apparatus, and FIG. 11 is a flowchart of the operation of the grinding apparatus.

  The grinding apparatus 1 according to the present embodiment is different from the first embodiment in the moving device 50, and the other configurations are the same as those in the first embodiment. In FIG. 5, portions corresponding to FIGS. By attaching the same reference numerals to the above, detailed description of the portions will be omitted, and different portions will be mainly described.

  The moving device 50 includes an actuator 51 that raises or lowers the rear portion of the base portion 11 to swing the base portion 11 in the vertical direction around the support shaft 9. The actuator 51 includes, for example, an electric motor 52 and an electric motor. 52 and a rear end portion of the base portion 11, and a transmission mechanism 53 that moves up and down the rear portion of the base portion 11 by the electric motor 52. Further, the moving device 50 includes a control device 57 that controls the operation of the actuator 51 based on the estimated threshold value of the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31.

  Here, the outer peripheral surface 8 of the metal bond grindstone 5 gradually decreases due to wear due to grinding and electrolytic dressing, as shown by an imaginary line 8a in FIG. 10, for example, and the electrode surface 35 of the electrode 31 for electrolytic dressing and the metal bond grindstone 5 The gap with the outer peripheral surface 8 increases. When the gap with the outer peripheral surface 8 of the metal bond grindstone 5 is increased, the electrolytic dressing efficiency is gradually lowered.

  When the decreasing outer peripheral surface 8 of the metal bond grindstone 5 reaches a predetermined diameter of the metal bond grindstone 5, the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31 is good. It is presumed that the threshold value for obtaining the grinding process has been reached by the outer peripheral surface 8 of the metal bond grindstone 5, and the actuator 51 is operated to swing the dressing device 10 from the reference position in the direction indicated by the phantom line 10a in FIG. Then, the gap between the downstream end 35b of the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap. For this reason, the control device 57 includes a grindstone diameter detection sensor 57a that detects the diameter of the outer peripheral surface 8 of the metal bond stone 5, and each grindstone diameter detected by the grindstone diameter detection sensor 57a becomes a preset estimated threshold value. Compared with the grindstone diameter, every time the grindstone diameter reaches the estimated threshold value, the actuator 51 is operated to swing the dressing device 10 about the support shaft 9, and the gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5. Adjust narrowly. Note that the diameter of the metal bond grindstone 5 serving as an estimated threshold can be easily set based on experiments or simulations.

  Next, the operation control of the grinding apparatus 1 will be described below based on the operation flowchart of the grinding apparatus of FIG.

  In FIG. 10, before starting the grinding with the metal bond grindstone 5, the electrode position adjustment unit 40 adjusts the gap between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5 to an intended gap. And prepare.

  The workpiece W is set in the workpiece holding mechanism of the grinding apparatus 1 (step S141). The grinding fluid is supplied from the grinding fluid supply source to the electrolytic dressing region between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 from the discharge hole 37 through the grinding fluid supply pipe 38 and the like, while the power supply is turned on. throw into. The current output from the power source flows through the apparatus main body, the main shaft 4, the metal bond grindstone 5, the grinding fluid, the electrode 31 for electrolytic dressing, the electric wire 39, and the path of the power source, and the electrolytic dressing is started. In this state, the spindle 2 is driven at a predetermined rotation speed, the metal bond grindstone 5 is rotated, and the workpiece W is rotated to start grinding (step S142).

  Conductive grinding fluid exists between the electrode surface 35 of the electrode 31 for electrolytic dressing and the outer peripheral surface 8 of the metal bond grindstone 5 during the cutting of the workpiece W, and energizes between the electrode 31 and the metal bond grindstone 5. Thus, the electrode 31 for electrolytic dressing becomes a cathode and the metal bond grindstone 5 becomes an anode, and the outer peripheral surface 8 of the metal bond grindstone 5 is electrolytically dressed.

  The diameter of the metal bond grindstone 5 being ground is detected, and it is determined whether or not the detected diameter has reached a preset estimated threshold value (step S143).

  And when it determines with the diameter of the detected metal bond grindstone 5 having reached the presumed threshold value (it is YES at step S143), grinding processing is complete | finished after that (step S144).

  In a state where the grinding process is completed and the rotation of the metal bond grindstone 5 is stopped, the actuator 51 is operated to move the dressing device 10 around the axis 9a of the support shaft 9 in the direction indicated by the imaginary line 10a in FIG. By swinging, the gap between the downstream end 35b of the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap (step S145).

  Next, the workpiece W for which grinding has been completed is removed from the workpiece holding mechanism and carried out (step S146).

  On the other hand, when it is determined in step S143 that the diameter of the metal bond grindstone 5 is larger than the estimated threshold (NO), the grinding process is finished thereafter (step S147), and the workpiece W is removed from the workpiece holding mechanism and carried out (step S146). ).

Therefore, for each amounts to an estimated threshold diameter metal bond grindstone 5 is preset in the machining of the workpiece W by the metal bonded grinding wheel 5, and swing the dressing apparatus 10 about the support shaft 9 by operating the actuator 51 The gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap, so that the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode 13 for electrolytic dressing is within an appropriate range. By maintaining this, stable electrolytic dressing efficiency is maintained, and the workpiece W is ground by the metal bond grindstone 5 that is always dressed well, so that high-quality grinding can be ensured.

( Reference example )
A reference example will be described with reference to FIGS. 12 to 14 as an example of grinding the outer peripheral surface of a shaft-shaped workpiece W. FIG. 12 is a diagram showing an outline of the grinding apparatus, and FIG. 13 is an enlarged view of a portion C in FIG. In FIGS. 12 and 13, parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description of the parts will be omitted, and different parts will be mainly described.

  The grinding device 1 is supported by a metal bond grindstone 5 mounted on a spindle 2 that is rotationally driven by an electric motor (not shown), and supported by a guide rail 2 so as to be linearly movable in the reference line L direction that contacts and separates the metal bond grindstone 5. The moving dressing device 10 and the moving device 60 that moves and adjusts the dressing device 10 in the direction of the reference line L that contacts and separates the metal bond grindstone 5 are provided.

  The moving device 60 includes an actuator 61 that is coupled to the rear portion of the base portion 11 and moves the dressing device 10 in the direction of the reference line L. The actuator 61 includes, for example, the electric motor 62 and the electric motor 62 and the rear end of the base portion 11. And a transmission mechanism 63 such as a feed screw mechanism that is laid between the two and reciprocatingly moves the base portion 11 in the direction of the reference line L by the electric motor 62. Further, the moving device 60 includes a control device 65 that controls the operation of the actuator 61 based on the estimated threshold value of the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31.

  Here, the outer peripheral surface 8 which becomes the grinding surface of the metal bond grindstone 5 gradually decreases by grinding and electrolytic dressing, for example, as shown by a virtual line 8a in FIGS. 12 and 13, and the outer peripheral surface 8 of the metal bond grindstone 5 is reduced. Since the gap increases and the increase in the gap with the outer peripheral surface 8 of the metal bond grindstone 5 greatly depends on the number of times of grinding of the workpiece W, when the number of times of grinding of the workpiece W reaches a preset number of times, the actuator 51 It is estimated that the gap between the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface 35 of the electrode for electrolytic dressing 31 has reached a limit threshold for obtaining a work grinding process by the outer peripheral surface 8 of the metal bond grindstone 5; Actuator 51 is actuated to move dressing device 10 along guide rail 2 toward metal bond grindstone 5 as shown by phantom line 10a in FIGS. And dynamic, adjusted to the desired gap between the outer peripheral surface 8 of the metal bond grinding wheel 5 which faces the electrode surface 35 of the electrolytic dressing electrode 31. For this reason, the control device 65 includes a grinding process count unit 65a that counts the number of times the workpiece W is ground. The control unit 65 compares the number of grindings performed by the count unit 65a with a preset number of times of cutting. Each time the set number of grinding operations is reached, the actuator 61 is operated to move the dressing apparatus 10 closer to the metal bond grindstone 5 side along the reference line L as shown by the imaginary line 10a in FIGS. The gap between the outer peripheral surface 8 of the opposing metal bond grindstone 5 and the electrode surface 3 of the electrolytic dressing electrode 31 is adjusted to a desired gap.

  Next, the operation control of the grinding apparatus 1 will be described below based on the operation flowchart of FIG.

  12 and 13, before starting the grinding by the metal bond grindstone 5, the electrode position adjustment unit 40 causes the electrode surface 35 of the electrode 31 for electrolytic dressing to have a gap with the outer peripheral surface 8 of the metal bond grindstone 5. Prepare to adjust.

  The workpiece W is set in the workpiece holding mechanism of the grinding apparatus 1 (step S151). The grinding fluid is supplied from the grinding fluid supply source to the electrolytic dressing region between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 from the discharge hole 37 through the grinding fluid supply pipe 38 and the like, while the power supply is turned on. throw into. The current output from the power source flows through the apparatus main body, the main shaft 4, the metal bond grindstone 5, the grinding fluid, the electrode 31 for electrolytic dressing, the electric wire 39, and the path of the power source, and the electrolytic dressing is started. In this state, the spindle 4 is driven at a predetermined rotation speed, the metal bond grindstone 5 is rotated, and the workpiece W is rotated to start grinding (step S152). It is determined whether this grinding has reached a predetermined number of grindings set in advance (step S153).

  If it is determined that the predetermined number of times of grinding has been reached (YES in step S153), then the grinding is terminated (step S154).

  In a state where the grinding process is finished and the rotation of the metal bond grindstone 5 is stopped, the actuator 61 is operated to show the dressing device 10 along the guide rail 2 reference line L in FIG. 12 and FIG. It moves to a direction and the clearance gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to a desired clearance (step S155).

  Next, the workpiece W for which grinding has been completed is removed from the workpiece holding mechanism and carried out (step S156).

  On the other hand, if it is determined in step S153 that the predetermined number of grinding processes has not been reached (NO), the grinding process is terminated (S157), and the workpiece W is removed from the workpiece holding mechanism. Unload (step S156).

  Therefore, each time the workpiece W is cut by the metal bond 5 reaches a preset number of times of grinding, the actuator 61 is actuated to move the dressing device 10 along the guide rail 2 and the opposing metal bond grindstone 5 The gap between the outer peripheral surface 8, the electrode surface 35 of the electrolytic dressing electrode 31 and the outer peripheral surface 8 of the metal bond grindstone 5 is adjusted to the desired gap, and the outer peripheral surface 8 of the metal bond grindstone 5 and the electrode surface of the electrode 13 for electrolytic dressing A stable electrolytic dressing efficiency is maintained by maintaining the gap with 35 in a good range, and the workpiece W is ground by the metal bond grindstone 5 that is always dressed well, so that high-quality grinding can be ensured.

In this reference example , each time the spindle current value in the cutting of the workpiece W by the metal bond 5 reaches the preset estimated threshold value, the actuator 61 is operated to set the dressing device 10 as a reference, as in the second embodiment. The gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 can be adjusted to the desired gap by moving along the line L.

  Similarly to the third embodiment, every time the electrolytic current value in the cutting of the workpiece W by the metal bond 5 reaches the preset estimated threshold value, the actuator 61 is operated to move the dressing device 10 along the reference line L. The gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 can be adjusted to the desired gap.

  Further, similarly to the fourth embodiment, each time the diameter of the metal bond grindstone 5 in the cutting of the workpiece W by the metal bond 5 reaches the preset estimated threshold value, the actuator 61 is operated to set the dressing device 10 to the reference line. The gap between the electrode surface 35 and the outer peripheral surface 8 of the metal bond grindstone 5 can also be adjusted to the desired gap by moving along L.

  The present invention is not limited to the above-described embodiment, and various changes can be made within the scope of the departure city within the spirit of the invention. For example, in each of the embodiments described above, the transmission mechanism such as the electric motor and the screw feed mechanism is used. However, the electric motor, the gear mechanism, the link mechanism, and the like may be used.

DESCRIPTION OF SYMBOLS 1 Grinding machine 4 Main axis | shaft 4a Rotation center axis 5 Metal bond grindstone 8 Outer surface (grinding surface)
9 Support shaft 9a Shaft core 10 Dressing device 31 Electrode dressing electrode 35 Electrode surface 50 Moving device W Workpiece

Claims (5)

A grinding device that grinds a workpiece by rotating a cylindrical metal bond grindstone in which abrasive grains are bonded by a conductive bond material with an electric motor, and has an interval between the outer peripheral surface of the metal bond grindstone and the grinding liquid. A power supply comprising a dressing device having an electrode for electrolytic dressing with electrode surfaces facing each other and energizing the metal bond grindstone and the electrode for electrolytic dressing with a grinding liquid interposed between the metal bond grindstone and the electrode for electrolytic dressing In a grinding apparatus for electrolytically dressing a metal bond grindstone by energizing a metal bond grindstone rotating in the presence of a grinding fluid and an electrode for electrolytic dressing,
The dressing device is swung around an axis parallel to the rotation center axis of the metal bond grindstone, and the downstream end of the electrode surface in the metal bond grindstone rotation direction is moved closer to the outer peripheral surface of the metal bond grindstone. It has a moving device that adjusts the gap between the outer peripheral surface of the grindstone and the electrode surface of the electrode for electrolytic dressing ,
The outer peripheral surface of the metal bonded grinding wheel and move the dressing device by the mobile device based on the estimated threshold to obtain a workpiece grinding quality Tokoro period in a direction electrolytic dressing electrode of said dressing device approaches the outer peripheral surface of the metal bond grindstone And a gap between the electrode surface of the electrode for electrolytic dressing and a desired interval. 2. The grinding apparatus according to claim 1 , wherein the estimated threshold value is a preset number of times the workpiece is ground by a metal bond grindstone . 2. The grinding apparatus according to claim 1 , wherein the estimated threshold value is a spindle current value that is a preset driving power of the electric motor . 2. The grinding apparatus according to claim 1 , wherein the estimated threshold value is an electrolytic current value of a grinding fluid interposed between the opposing electrode surface and the outer peripheral surface of the metal bond grindstone . The grinding apparatus according to claim 1 , wherein the estimated threshold value is set according to an outer peripheral diameter of a worn metal bond grindstone.

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