JP2008229786A - Method of honing cylinder bore inner peripheral surface, and device for honing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of honing a cylinder bore inner peripheral surface, which brings about simplification of a device, is excellent in working efficiency, and contributes to reduction of manufacturing costs. <P>SOLUTION: According to the method, an electrolytic dressing electrode 35 is provided for a dummy head 30, and voltage is applied to a honing grindstone 20 and the electrolytic dressing electrode 35 opposed to each other in the presence of a conducting fluid supplied from fluid supply means 26, to thereby carry out electrolytic dressing of the honing grindstone 20. In the dummy head 30 on which the electrolytic dressing electrode 35 is arranged, by carrying out the electrolytic dressing of the honing grindstone 20, honing is achieved without dispersion of surface roughness and with stability. Thus the present method can be implemented without largely changing an existing honing device, which contributes to reduction of manufacturing costs without complication of the device and honing work. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a honing method and a honing device for honing an inner peripheral surface of a cylinder bore formed in a cylinder block.

  Conventionally, honing by a honing device has been applied to finish processing of a cylindrical inner peripheral surface of a work material that requires high accuracy, such as a cylinder bore of an automobile engine. Honing is a processing method that efficiently improves processing accuracy such as roundness, straightness, and surface roughness of a cylindrical inner peripheral surface processed by precision boring, grinding, or the like.

  The honing device has, for example, a honing tool in which square rod-shaped honing grinds are radially arranged. The honing tool applies a radially outward contact pressure to the honing grindstone in contact with the cylindrical inner surface of the work material, and rotates the honing tool. However, the inner peripheral surface of the cylinder is ground by applying a reciprocating motion in the rotation axis direction.

  According to the honing process by the honing apparatus, a grinding trace having a special mesh pattern called a cross hatch is formed by a honing grindstone that reciprocates simultaneously with rotation. This cross hatch has a function of retaining lubricating oil required for the cylinder bore of the engine.

  In general, a honing grindstone is a square bar shape in which extremely hard and small abrasive grains such as aluminum oxide, silicon carbide, diamond and the like are bound by a binder, and the grindstone itself is dressed simultaneously by grinding the work material. A grindstone with excellent self-generation (a phenomenon in which worn abrasive grains fall off and new abrasive grains protrude) is selected.

  However, since the dressing of the honing wheel depends on the self-generated action of the grinding wheel itself, the processing accuracy of the work material in the previous process by precision boring, grinding, etc., the variation in the shape due to the manufacturing of the grinding wheel itself, honing processing Due to the contamination of the grinding fluid used for the honing wheel, the self-acting cycle of the honing grindstone varies.

  If there is variation in the self-acting cycle of this honing wheel, clogging with chips and drop-off crushed grains in the honing wheel gap during honing processing, clogging that does not crush even if abrasive grains wear, Concerns may arise, such as excessive grinding resistance and impact, which may cause spillage of abrasive grains, leading to deterioration of the machined surface roughness, grinding burn of the machined surface, grinding cracks, etc., and excessive machining time. Is done. For this reason, it is necessary to dress the honing grindstone frequently.

  On the other hand, in recent years, a metal bond grindstone in which abrasive grains are bonded to a honing grindstone with a conductive bonding portion of bronze or cast iron is often used. Various electrolytic dressings have been proposed as dressing methods for this type of honing grindstone.

  For example, in the honing grindstone dressing method disclosed in Patent Document 1, an electrolytic dress grindstone holder 102 is attached to the main shaft of the honing head 101 as shown in FIG. 7, and abrasive grains and a conductive coupling portion are attached to the grindstone holder 102. On the other hand, an electrode 103 having an arcuate facing surface 103a that is opposed to the outer peripheral surface serving as a processing surface of the honing grindstone 105 positioned and fixed to the grindstone holder 102 with a predetermined interval is disposed. In addition, a conductive grinding liquid such as a water-soluble coolant is supplied to the facing surface 103a through the flow path 103b, and a voltage applying means 104 such as a power supply device for applying a predetermined voltage between the honing grindstone 105 and the electrode 103 is provided. Yes. Then, a predetermined voltage is applied between the honing grindstone 105 and the electrode 103, and at the same time, a conductive grinding liquid such as an aqueous coolant is supplied between the honing grindstone 105 and the electrode 103, thereby conducting the electrical conductivity of the outer surface of the honing grindstone 105. The sexual coupling part is electrolyzed (electrolyzed) and dressed with protruding abrasive grains.

  Further, in the electrolytic dressing of Patent Document 2, as shown in FIG. 8, a work material 112 is attached to a rotating chuck 111 of a turning center processing machine, and a metal bond grindstone 115 is attached to a chuck (not shown) that can be driven to reciprocate in opposition thereto. And an electrode 114 having an electrode surface 114a facing the grindstone 115 and a grinding fluid supply hole 114b. The grindstone 115 is driven back and forth between the work material 112 and the electrode 114 while the grindstone 115 and the electrode 114 are A predetermined voltage is applied between them, and at the same time, a conductive grinding liquid such as a water-soluble coolant is supplied from the grinding liquid supply hole 114b between the grindstone 115 and the electrode 114 to perform electrolytic dressing and grinding alternately.

  On the other hand, in the cylinder block of an engine, the cylinder bore has become thinner and non-uniform due to the weight reduction of the cylinder block, so the cylinder head is assembled and fixed on the cylinder block by tightening bolts. When this occurs, there is a concern that stress is generated in the cylinder block due to a load applied with bolt fastening, and the inner peripheral surface of the cylinder bore is deformed into a non-circular shape. As a countermeasure against this, the honing method for the inner peripheral surface of the cylinder bore disclosed in Patent Document 3 applies the same load load to the cylinder block as when the dummy head is bolted on the upper deck portion of the cylinder block and the cylinder head is actually bolted. Honing is performed on the inner peripheral surface of the cylinder bore. After that, when the dummy head is removed, the cylinder bore inner peripheral surface honed into a perfect circle shape is deformed into a non-circular shape by the restoring action accompanying the release of the load load, but after that, the cylinder head is attached to the cylinder block. When the bolts are actually mounted and fixed, the cylinder bore inner peripheral surface changes from a non-round shape to a perfect circle shape based on the load applied by the bolt fastening.

JP 2001-62721 A Japanese Patent No. 2838314 JP 2005-199378 A

  According to the above-mentioned patent document 1, when dressing the honing grindstone 105, the grindstone holder 102 for the electrolytic dress is attached to the main shaft of the honing head 101, and the honing grindstone 105 is attached to the grindstone holder 102 for electrolytic dressing. A grindstone holder 102 for electrolytic dressing is attached to the main shaft instead of the honing tool, and the honing grindstone 105 removed from the honing tool is attached to the grindstone holder 102. After dressing, the honing grindstone 105 is attached to the honing tool again and honing is performed. The troublesome work which removes the grindstone holder 102 from the spindle of the head 101 and attaches the honing tool is required, and a lot of man-hours are required for dressing the honing grindstone 105. Affect the engineering cycle, there is a concern that lowering the honing work efficiency.

  Further, according to Patent Document 2, a predetermined voltage is applied between the grindstone 115 and the electrode 114 while reciprocating the grindstone 115 between the workpiece 112 and the electrode 114, and at the same time between the grindstone 115 and the electrode 114. Since electroconductive dressing and cutting are alternately performed by supplying a conductive grinding liquid such as a water-soluble coolant between them, machining accuracy can be improved.

  On the other hand, according to Patent Document 1 and Patent Document 2, roundness is ensured in the honing of a cylinder block with a thin and non-uniform thickness of the cylinder bore due to the weight reduction of the cylinder block. When a dummy head such as that disclosed in Patent Document 3 is mounted, the apparatus and work are complicated because the electrolytic dressing means and the dummy head are provided, and there is a concern about an increase in manufacturing cost.

  Accordingly, an object of the present invention made in view of the above point is to provide a honing method and a honing device for the inner peripheral surface of a cylinder bore which are excellent in simplification of the apparatus and work efficiency and can be expected to reduce the manufacturing cost.

  The honing method for the inner peripheral surface of the cylinder bore according to claim 1, which achieves the above object, is inserted through a cylindrical dummy head mounted on the upper deck portion of the cylinder block, and the abrasive grains are fixed by the conductive coupling portion. In the honing method for the cylinder bore inner circumferential surface, in which the honing tool equipped with the honing grindstone is used for honing the inner circumferential surface of the cylinder bore of the cylinder block, the honing tool inserted into the dummy head is mounted on the honing tool. The honing grindstone is provided with an electrode for electrolytic dressing opposed to the honing grindstone with a gap through which the conductive liquid is interposed, and a voltage is applied to the facing honing grindstone and the electrode for electrolytic dressing in the presence of the conductive liquid. Is characterized by electrolytic dressing.

  According to the present invention, when the inner peripheral surface of the cylinder bore of the cylinder block to which the dummy head is attached is honed by the honing tool, the honing grindstone is subjected to electrolytic dressing in the dummy head provided with the electrode for electrolytic dressing. This makes it possible to perform honing with a stable quality without variation in surface roughness.

  In addition, since the electrolytic dressing in the dummy head is performed at the timing when the honing tool is present in the dummy head, the electrolytic dressing can be performed without giving a special operation or cycle for dressing. Since the electrodes are arranged on the dummy head, it is not necessary to provide a new electrolytic dressing means, and it can be realized without greatly changing the existing honing device, and the manufacturing cost can be reduced without complicating the device and work. I can expect.

  The honing method of the cylinder bore inner peripheral surface according to claim 2 is a honing grindstone in which abrasive grains are fixed by a conductive coupling portion through a cylindrical dummy head mounted on an upper deck portion of a cylinder block. In the honing method for the cylinder bore inner circumferential surface, in which the honing tool with the cylinder block is used for honing the inner circumferential surface of the cylinder bore of the cylinder block, the honing tool that is disposed in the dummy head and is inserted into the dummy head is mounted. Electrodes for electrolytic dressing arranged opposite to each other with a gap for interposing a conductive liquid with the honing grindstone, a liquid supply means for supplying the conductive liquid into the dummy head, the honing grindstone, and an electrode for electrolytic dressing Voltage applying means for applying a voltage to the liquid, and supplied by the liquid supply means Applying a voltage by the voltage application means the presence opposing honing grindstone at a the electrolytic dressing electrode conductive liquid to be characterized by electrolytically dressed honing grindstone.

  According to this invention, when honing is performed on the inner peripheral surface of the cylinder bore of the cylinder block to which the dummy head is attached by the honing tool, the dummy head is provided in the opposing dummy head in the presence of the conductive liquid supplied from the liquid supply means. Since the electrolytic dressing is applied to the honing grindstone by applying a voltage to the electrolytic dressing electrode and the honing grindstone by means of voltage application means, it is possible to perform honing with stable quality without variation in surface roughness.

  In addition, since the electrolytic dressing in the dummy head is performed at the timing when the honing tool is present in the dummy head, the electrolytic dressing can be performed without giving a special operation or cycle for dressing. Since the electrode for electrolytic dressing is disposed on the dummy head, it is not necessary to newly provide electrolytic dressing means, and it can be realized without greatly changing the existing honing device, and the manufacturing cost does not cause complication of the device and work. Reduction can be expected.

  The invention of the honing apparatus for the inner peripheral surface of the cylinder bore according to claim 3 is a honing grindstone in which abrasive grains are fixed by a conductive coupling portion through a cylindrical dummy head mounted on an upper deck portion of a cylinder block. In the honing apparatus for the cylinder bore inner peripheral surface, in which the inner peripheral surface of the cylinder bore of the cylinder block is honed by the honing tool mounted with the cylinder block, mounted on the honing tool disposed in the dummy head and inserted into the dummy head Electrodes for electrolytic dressing arranged opposite to each other with a gap for interposing a conductive liquid with the honing grindstone, a liquid supply means for supplying the conductive liquid into the dummy head, the honing grindstone, and an electrode for electrolytic dressing Voltage applying means for applying a voltage to the liquid, and supplied by the liquid supply means Applying a voltage by the voltage application means the presence opposing honing grindstone at a the electrolytic dressing electrode conductive liquid to be characterized by electrolytically dressed honing grindstone.

  According to this invention, when honing is performed on the inner peripheral surface of the cylinder bore of the cylinder block to which the dummy head is attached by the honing tool, the dummy head is provided in the opposing dummy head in the presence of the conductive liquid supplied from the liquid supply means. Since the electrolytic dressing is applied to the honing grindstone by applying a voltage to the electrolytic dressing electrode and the honing grindstone by means of voltage application means, it is possible to perform honing with stable quality without variation in surface roughness.

  In addition, since the electrolytic dressing in the dummy head is performed at the timing when the honing tool is present in the dummy head, the electrolytic dressing can be performed without giving a special operation or cycle for dressing. Since the electrode for electrolytic dressing is disposed on the dummy head, it is not necessary to newly provide electrolytic dressing means, and it can be realized without greatly changing the existing honing device, and the manufacturing cost does not cause complication of the device and work. Reduction can be expected.

  According to a fourth aspect of the present invention, in the honing apparatus for the inner peripheral surface of the cylinder bore according to the third aspect, electrolytic dressing is performed every time the honing tool passes through the dummy head.

  According to the present invention, when performing honing with a honing tool repeatedly, the honing grindstone is subjected to electrolytic dressing using the conductive liquid in the dummy head on which the electrode for electrolytic dressing is disposed. Stable quality honing without any problems is possible.

  According to a fifth aspect of the present invention, in the honing apparatus for the inner peripheral surface of the cylinder bore according to the third aspect, electrolytic dressing is performed for each preset number of honing processes.

  The present invention was made by paying attention to the fact that the grinding ability gradually decreases and the processing time gradually increases when the abrasive grains are worn by grinding, and the electrolytic dressing is performed every preset number of honing processes. Thus, excessive sharpening of the grindstone by electrolytic dressing is suppressed, the processing time is shortened, and the efficiency of the processing cycle can be improved.

  A sixth aspect of the present invention is the honing apparatus for an inner peripheral surface of the cylinder bore according to any one of the third to fifth aspects, wherein the honing tool is radially provided on an outer periphery of the honing tool main body that is supported and rotated by the main shaft. The electrode for electrolytic dressing is a cylindrical shape that allows the insertion of the honing tool main body supported by the main shaft and the honing grindstone, and the electrode surface is opposed to each honing grindstone at intervals. It is characterized by being.

  In the present invention, the honing tool and the electrode for electrolytic dressing are limited to a specific configuration, and the honing tool is rod-shaped honing that is radially arranged on the outer periphery of a honing tool body that is supported by a main shaft and rotated. A grindstone is provided. Moreover, the electrode for electrolytic dressing arrange | positioned at a dummy head is formed in the cylindrical shape according to the honing tool.

  The invention as set forth in claim 7 is the honing apparatus for the cylinder bore inner peripheral surface according to any one of claims 3 to 5, wherein the honing tool is supported radially on the outer periphery of the honing tool main body supported by the main shaft and driven to rotate. The rod-shaped honing grindstone disposed on the electrode, and the electrode for electrolytic dressing is a radial shape that allows insertion of the honing tool main body and honing grindstone supported by the main shaft, and the electrode surfaces are opposed to each honing grindstone at intervals. A plurality of electrodes arranged in the above.

  In the present invention, the honing tool and the electrode for electrolytic dressing are limited to a specific configuration, and the honing tool is rod-shaped honing that is radially arranged on the outer periphery of a honing tool body that is supported by a main shaft and rotated. A grindstone is provided. Moreover, the electrode for electrolytic dressing arrange | positioned at a dummy head consists of a several electrode arrange | positioned radially according to a honing tool.

  According to the present invention, when the inner peripheral surface of the cylinder bore of the cylinder block to which the dummy head is attached is subjected to honing with a honing tool, the honing grindstone is subjected to electrolytic dressing in the dummy head provided with the electrode for electrolytic dressing. Stable quality honing with no variation in surface roughness is possible. Further, it can be realized without greatly changing the existing honing apparatus, and reduction in manufacturing cost can be expected without complicating the apparatus and work.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a honing method and a honing apparatus for a cylinder bore inner peripheral surface according to the present invention will be described below with reference to FIGS.

  FIG. 1 is a schematic explanatory diagram of the honing device 1, FIG. 2 is a configuration diagram of the honing tool 10, and FIG. 3 is a view taken in the direction of arrow A in FIG.

  First, as shown in FIG. 1, the cylinder block 50 in the present embodiment is integrally formed with a cylinder part 52 in which a cylinder bore 51 is formed and a crankcase part 55 having a substantially skirt shape in a side view at the lower part of the cylinder part 52. ing. An upper deck portion 53 to which a cylinder head is attached and fixed via a gasket (not shown) is formed on the upper portion of the cylinder portion 52. Bolt holes 53 a are formed in the upper deck portion 53, a cylinder head is placed on the upper deck portion 53 via a gasket, and a head bolt is screwed into the bolt hole 53 a of the upper deck portion 53, whereby the cylinder head is fitted to the cylinder block 50. Is concluded.

  Next, the honing apparatus 1 in this Embodiment is demonstrated.

  As shown in FIG. 1, the honing device 1 has a base portion 2 on which a cylinder block 50 can be placed, and the upper surface of the base portion 2 is a honing processing position. A clamping device (not shown) for positioning and fixing 50 is provided.

  The honing tool 10 above the base portion 2 and the honing tool main body 11 of the honing tool 10 descending from above are guided and guided into a cylinder bore 51 of the cylinder block 50, and a water-based coolant is inserted into a dummy head 30 described later. A liquid supply means 26 for supplying a conductive liquid such as, a work loading / unloading means for loading and unloading the cylinder block 50 to which the dummy head 30 is attached, and a voltage application means are arranged.

  The honing device 1 is swingably supported by a main shaft 5 of a honing head having a driving device such as a main shaft motor, and the main shaft 5 is configured to be able to drive a honing tool 10 about a rotation axis Z. As shown in FIGS. 2 and 3, the honing tool 10 has a hollow cylindrical honing tool main body 11 supported by the main shaft 5, and extends along the rotation axis Z direction on the outer periphery of the honing tool main body 11. A plurality of honing shoe guide holes 12 are opened at equal intervals, and the first honing shoe 13A and the second hosing are slidably guided in the honing shoe guide holes 12 so as to be movable in the radial direction contacting and separating from the rotation axis Z. The shoes 13B are alternately fitted and attached.

  In the first honing shoe 13A and the second honing shoe 13B, a grindstone mounting groove 13a extending along the rotation axis Z direction is formed on the outer end surface, and both side surfaces 13b are slidable on the end surface 12b of the honing shoe guide hole 12. The engaging grooves 13c and 13d are formed at both ends of the outer peripheral surface, respectively.

  A proximal-side tapered surface 13Aa and a distal-side tapered surface 13Ab that gradually approach the rotation axis Z are formed on the proximal end side and the distal end side of the inner end surface of the first honing shoe 13A as they move from the proximal end side to the distal end side. Yes. A proximal-side tapered surface 13Ba and a distal-side tapered surface 13Bb that gradually approach the rotation axis Z are formed on the proximal end side and the distal end side of the inner end surface of the second honing shoe 13B, respectively, as they move from the proximal end side to the distal end side. Yes. The engaging grooves 13c and 13d of the first honing shoe 13A and the second honing shoe 13B are fitted with annular spring bands 14a and 14b serving as a diameter biasing biasing means, and the spring bands 14a and 14b Each of the first honing shoes 13A and the second honing shoes 13B is urged in the direction of the central axis Z, that is, in the radially inward direction.

  A rod-shaped honing grindstone 20 extending along the rotation axis Z direction is attached to each grindstone mounting groove 13a of the first honing shoe 13A and the second honing shoe 13B. The honing grindstone 20 is composed of, for example, a metal bond grindstone in which abrasive grains such as diamond, CBN (cubic boron nitride), crystalline aluminum oxide, silicon carbide, and the like are bonded by a conductive bonding portion made of bronze or cast iron. Yes.

  Further, a plurality of honing guide member mounting grooves 11a extending along the rotation axis Z direction at equal intervals are formed on the outer periphery of the honing tool main body 11, and the honing guide member mounting grooves 11a are made of ceramic or the like via the mounting member 15. A honing guide member 16 extending in the direction of the rotation axis Z is attached. The distance from the rotation axis Z to the outer peripheral surface 16a of each honing guide member 16 is formed constant. Further, an air passage 11b for an air micrometer (not shown) for accurately measuring the gap between the outer peripheral surface 16a of the honing guide member 16 and the processing surface by air pressure is formed in the honing tool main body 11, and the outer peripheral surface 16a of the honing guide member 16 is formed. Is open.

  A proximal end taper penetrating through the honing tool body 11 and slidably comes into contact with the proximal end tapered surface 13Aa and the distal end tapered surface 13Ab of the first honing shoe 13A and gradually approaches the rotation axis Z as it moves downward. A first expansion / contraction bar 17 </ b> A having a surface 17 </ b> Aa and a tip-side tapered surface 17 </ b> Ab is disposed in the honing tool main body 11. Further, a base which is coupled to the first expansion / contraction bar 17A and slidably contacts the proximal side taper surface 13Ba and the distal side taper surface 13Bb of the second honing shoe 13B and gradually approaches the rotation axis Z as it moves to the distal end side. A second expansion / contraction bar 17B in which the end tapered surface 17Ba and the tip tapered surface 17Bb are formed is disposed in the honing tool main body 11.

  The first expansion / contraction bar 17A and the second expansion / contraction bar 17B are pulled upward and released by a pulling mechanism (not shown) disposed in the honing head. The first expansion / contraction bar 17A and the second expansion / contraction bar 17B are always urged downward by a spring 18 disposed in the honing tool main body 11.

  By releasing the traction by the traction operation mechanism of the honing head, the proximal end side taper surface 17Aa and the front end side taper surface 17Ab of the first expansion / contraction bar 17A are urged by the spring 18 and the proximal end side taper surface 13Aa of the first honing shoe 13A and The first honing shoes 13A are pushed outward in the radial direction away from the central axis Z while being pressed against the tip side taper surface 13Ab. Similarly, the proximal end tapered surface 17Ba and the distal end tapered surface 17Bb of the second expansion / contraction bar 17B are in pressure contact with the proximal end tapered surface 13Ba and the distal end tapered surface 13Bb of the second honing shoe 13B, respectively. 13B is pushed outward in the radial direction away from the central axis Z.

  On the other hand, by pulling the first expansion / contraction bar 17A and the second expansion / contraction bar 17B by the pulling operation mechanism against the urging of the spring 18, the proximal-side taper surface 17Aa and the distal-side taper surface 17Ab of the first expansion / contraction bar 17A. The second honing shoe by the proximal end taper surface 17Ba and the distal end side taper surface 17Bb of the second expansion / contraction bar 17B is released, while the pressing of the proximal end taper surface 13Aa and the distal end side taper surface 13Ab of the first honing shoe 13A is released. The pressing of the proximal end taper surface 13Ba and the distal end taper surface 13Bb of 13B is released. The first honing shoe 13A and the second honing shoe 13B released from the pressure by the first expansion / contraction bar 17A and the second expansion / contraction bar 17B are moved in the direction of the rotation axis Z, that is, in the diameter reduction direction by the spring bands 14a and 14b. .

  In addition, an insulation process is performed between the first expansion / contraction bar 17A and the second expansion / contraction bar 17B of the honing tool 10 and the honing head, and an electrode 23 is provided on the honing tool main body 11. The electrode 23 and each honing grindstone 20 are connected to each other through the honing tool body 11, the first honing shoe 13A, and the second honing shoe 13B so as to be conductive.

  During the honing process, the dummy head 30 is disposed on the upper deck portion 53 of the cylinder block 50. As shown in FIGS. 1 and 4, the dummy head 30 includes a hollow cylindrical dummy head main body 31 that has a mounting surface 31 a mounted on the upper deck portion 53 of the cylinder block 50 and extends in the direction of the rotation axis Z. The dummy head body 31 is fastened to the upper deck portion 53 of the cylinder block 50 by a mounting bolt 32 that is made of a conductive material, for example, iron and is screwed into the bolt hole 53a.

  A cylindrical electrolytic dressing electrode (hereinafter referred to as ELID electrode) 35 is provided on the inner periphery of the dummy head body 31 with a cylindrical insulating member 33 made of, for example, NC nylon fixed by a bolt 34. Yes. The ELID electrode 35 is made of, for example, iron, and its electrode surface 35a allows insertion of the honing tool main body 11 and the honing grindstone 20 that are supported by the spindle 5 and descend from above, and the outer surface 21 of the honing grindstone 20 It has an inner diameter in which a gap, for example, about 1 to 5 mm is formed to allow the conductive liquid to be opposed, and has a length in the direction of the rotation axis Z slightly larger than the length of the honing grindstone 20. Further, the ELID electrode 35 is connected to an electrode terminal 36 protruding outward from the dummy head body 31.

  Further, when the cylinder block 50 to which the dummy head 30 is attached by the loading / unloading means is loaded into the base portion 2, the electrode terminal 36 provided on the dummy head 30 is connected to the negative electrode (-electrode) of the voltage applying means, It is comprised so that it may isolate | separate from the negative electrode of a voltage application means with the carrying out from the base part 2. FIG.

  On the other hand, in the honing tool 10, the electrode 23 provided on the honing tool main body 11 is connected to the positive electrode (+ electrode) of the voltage applying means in a state where the honing tool main body 11 is inserted into the dummy head 30. It is comprised so that it may isolate | separate from the positive electrode of a voltage application means with the escape movement from.

  Next, the operation of the honing device 1 configured as described above will be described.

  As shown in FIG. 1, in a state where the honing tool 10 is held at the raised position, the cylinder block 50 fastened to the upper deck portion 53 by the mounting bolt 32 for screwing the dummy head 30 into the bolt hole 53a in advance is loaded by the work loading / unloading means. It carries in on the base part 2, mounts in a honing process position, and fixes the cylinder block 50 with a clamp apparatus. As the cylinder block 50 is carried in, the electrode 36 provided on the dummy head 30 is connected to the negative electrode of the voltage applying means.

  Next, an aqueous coolant, which is a conductive liquid, is supplied from the liquid supply means 26 into the dummy head 30, and as shown in FIGS. 4 and 5, the first expansion / contraction bar 17A of the honing tool 11 is pulled by the traction operation mechanism of the honing head. Then, the honing tool 10 in a reduced diameter state in which the first honing shoe 13A and the second honing shoe 13B are moved in the rotation axis Z direction, that is, the diameter reducing direction by pulling the second expansion / contraction bar 17B upward in the drawing is inserted from above. It is inserted into the dummy head 30 while being guided by the guide 25. As the honing tool 10 is inserted into the dummy head 30, the electrode 23 provided on the honing tool main body 11 is connected to the positive electrode of the voltage applying means, and the outer surface 21 of each honing grindstone 20 of the honing tool 10 is aqueous. It faces the electrode surface 35a of the ELID electrode 35 with a coolant interposed therebetween.

  While the outer surface 21 of the honing grindstone 20 and the electrode surface 35a of the ELID electrode 35 face each other, a negative voltage is applied from the voltage applying means to the ELID electrode 35, and the honing tool body 11 is applied from the electrode 23 by the voltage applying means. Then, a positive voltage is applied to each honing grindstone 20 via the honing shoes 13A and 13B, and the electroconductive dressing is electrolyzed on the outer surface 21 of each honing grindstone 20 by electrolytic action to perform electrolytic dressing. In this electrolytic dressing, since the aqueous coolant interposed between the electrode surface 35a of the ELID electrode 35 and the outer surface 21 of the honing grindstone 20 is excellent in conductivity, a stable electrolytic dressing can be obtained. The electrolytic dressing time is determined by the electrolytic voltage, the amount of abrasive grain protrusion, the material of the conductive joint, and the like, but can be set within several seconds. Moreover, the protrusion amount of the abrasive grains can be optimized by the electrolytic voltage and the electrolytic dressing time.

  When the electrolytic dressing of the honing grindstone 20 is completed, the honing tool 10 in a reduced diameter state is inserted into the cylinder bore 51 of the cylinder block 50 by the lifting / lowering mechanism of the honing head as shown in FIG. As the honing tool 10 moves into the cylinder bore 51, the electrode 23 provided on the honing tool body 11 is disconnected from the positive electrode of the voltage applying means.

  While the honing tool body 11 is inserted into the cylinder bore 51, the honing tool 11 is moved in the direction of the rotation axis Z while rotating the honing tool 11 while supplying the aqueous coolant, and the first expansion / contraction bar 17A of the honing tool 11 by the traction operation mechanism and The traction of the second expansion / contraction bar 17B is released. By releasing the traction, the first expansion / contraction bar 17A and the second expansion / contraction bar 17B move to the distal end side by the urging force of the spring 18, that is, descend in the drawing, and the proximal end taper surface 17Aa and the distal end taper surface of the first expansion / contraction bar 17A. 17Ab respectively presses against the proximal end side tapered surface 13Aa and the distal end side tapered surface 13Ab of the first honing shoe 13A to push each first honing shoe 13A outward in the radial direction away from the rotation axis Z. Similarly, the proximal end tapered surface 17Ba and the distal end tapered surface 17Bb of the second expansion / contraction bar 17B are in pressure contact with the proximal end tapered surface 13Ba and the distal end tapered surface 13Bb of the second honing shoe 13B, respectively. The outer surface 21 of each honing grindstone 20 comes into contact with the inner peripheral surface 51 a of the cylinder bore 51 by pushing 13B outward in the radial direction away from the rotation axis Z. And the inner peripheral surface 51a of the cylinder bore 51 is ground by the honing grindstone 20 with a preset contact pressure, that is, honing is started.

  A gap between the outer peripheral surface 16a of the honing guide member 16 and the inner peripheral surface 51a of the cylinder bore 51 serving as a processing surface is detected by an air micrometer while honing is performed, and the outer peripheral surface 16a of the honing guide member 16 and the inner peripheral surface of the cylinder bore 51 are detected. When the gap with 51a reaches a predetermined value, the first expansion / contraction bar 17A and the second expansion / contraction bar 17B are pulled upward by the traction operation mechanism, and the proximal end side taper surface 17Aa and the distal end side taper surface 17Ab of the first expansion / contraction bar 17A. The second honing shoe 13B by the proximal end tapered surface 17Ba and the distal end tapered surface 17Bb of the second expansion / contraction bar 17B is released while the pressing of the proximal end tapered surface 13Aa and the distal end tapered surface 13Ab of the first honing shoe 13A is released. The pressing of the proximal end side tapered surface 13Ba and the distal end side tapered surface 13Bb is released. As a result, the first honing shoe 13A and the second honing shoe 13B are moved in the rotation axis Z direction, that is, the diameter reducing direction by the spring bands 14a and 14b, so that each honing grindstone 20 is separated from the inner peripheral surface 51a of the cylinder bore 51. This completes the honing process. The machining time is from the start of the honing process to the end of the honing process.

  When the honing process is completed, the rotation of the honing tool 10 and the reciprocation in the rotation axis Z direction are stopped, the honing head is raised, and the honing tool main body 11 is moved from the cylinder bore 51 into the dummy holder 30. The outer surface 20a of the honing grindstone 20 is opposed to the electrode surface 35a of the ELID electrode 35 with an aqueous coolant interposed.

  While the outer surface 20a of the honing grindstone 20 and the electrode surface 35a of the ELID electrode 35 face each other, a negative voltage is applied from the voltage applying means to the ELID electrode 35, and the voltage applying means passes the honing shoes 13A and 13B. Then, a positive voltage is applied to each honing grindstone 20, and the electroconductive dressing is electrolyzed on the outer surface 21 of each honing grindstone 20 by electrolytic action to perform electrolytic dressing.

  When the electrolytic dressing of the honing grindstone 20 is completed, the supply of the aqueous coolant from the liquid supply means 26 is stopped, and the honing tool 10 is moved from the dummy head 30 to the raised position shown in FIG.

  Next, the fixing of the cylinder block 50 by the clamping device is released, and the cylinder block 50 in which the inner peripheral surface 51a of the cylinder bore 51 is honed is carried out from the base portion 2 by the work loading / unloading means. As the cylinder block 50 is carried out, the electrode 36 provided on the dummy head 30 is separated from the negative electrode of the voltage applying means.

  By repeating the steps from loading to unloading of the cylinder block 50 by the loading / unloading means, honing is applied to the inner peripheral surface 51a of the cylinder bore 51 of the cylinder block 50 by the honing grindstone 20 of the honing tool 10 subjected to electrolytic dressing. be able to.

  Therefore, according to the present embodiment, when the honing process is repeatedly performed on the inner peripheral surface 51a of the cylinder bore 51 of the cylinder block 50 to which the dummy head 30 is attached by the honing tool 10 attached to the main shaft 5 of the honing head, the ELID Electrolytic dressing is applied to the honing grindstone 20 using a conductive grinding liquid such as aqueous coolant in the dummy head 30 provided with the electrode 35, thereby enabling a stable quality honing process without variation in surface roughness. Become. In addition, excessive wear of the honing grindstone 20 is suppressed, and work efficiency is improved as the machining time is shortened.

  Further, since the electrolytic dressing in the dummy head 30 is performed in a state where the honing tool 10 is attached to the main shaft 5 of the honing head and the honing tool 10 is present in the dummy head 30, special operations and cycles for dressing are performed. Electrolytic dressing can be performed without application.

  Further, since the ELID electrode 35 is disposed on the dummy head 30, it is not necessary to newly provide an electrolytic dressing means, and it can be realized without greatly changing the existing honing device, resulting in complication of the device and work. Therefore, the manufacturing cost can be reduced. This is particularly useful when honing is performed on a small number of cylinder heads.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the cylindrical ELID electrode 35 is disposed on the dummy head 30, but a plurality of plate-shaped ELID electrodes extending in the rotation axis Z direction may be radially disposed. Further, a plurality of annular ELID electrodes can be arranged in the direction of the rotation axis Z, and ELID electrodes having various shapes can be arranged.

  In the embodiment described above, the electrolytic dressing is applied to the honing grindstone 20 for each honing process. However, it is also possible to measure the machining time and apply the electrolytic dressing to the honing grindstone 20 for each preset machining time. Alternatively, electrolytic dressing can be applied every preset number of honing operations.

  Furthermore, in the said embodiment, although conductive grinding liquids, such as aqueous coolant, were used as a conductive liquid, not only this but an appropriate conductive liquid can be used.

It is an outline explanatory view of a honing device concerning an embodiment of the invention. It is explanatory drawing of a honing tool. FIG. 3 is a view as seen from an arrow A in FIG. 2. It is sectional drawing of a dummy head. It is a figure which shows the outline | summary of an electrolytic dressing state. It is a figure which shows the outline | summary of a honing process state. It is a schematic diagram of the electrolytic dressing means of the conventional honing grindstone. It is a schematic diagram of the electrolytic dressing means of the conventional honing grindstone.

Explanation of symbols

1 Honing device 5 Spindle 20 Honing grindstone 26 Liquid supply means 30 Dummy head 35 Electrode dressing electrode (ELID electrode)
35a Electrode surface 50 Cylinder block 51 Cylinder bore 51a Inner peripheral surface 52 Cylinder part 53 Upper deck part

Claims (7)

The inner peripheral surface of the cylinder bore of the cylinder block is honed with a honing tool that is inserted through a cylindrical dummy head mounted on the upper deck of the cylinder block and equipped with a honing grindstone with abrasive grains fixed by a conductive joint. In the honing method for the cylinder bore inner peripheral surface,
The dummy head is provided with an electrode for electrolytic dressing opposed to the honing grindstone mounted on the honing tool inserted into the dummy head with a gap interposing a conductive liquid,
A honing method for an inner peripheral surface of a cylinder bore, wherein a voltage is applied to the honing grindstone and the electrode for electrolytic dressing facing each other in the presence of the conductive liquid to electrolytically dress the honing grindstone. The inner peripheral surface of the cylinder bore of the cylinder block is honed with a honing tool that is inserted through a cylindrical dummy head mounted on the upper deck of the cylinder block and equipped with a honing grindstone with abrasive grains fixed by a conductive joint. In the honing method for the cylinder bore inner peripheral surface,
An electrode for electrolytic dressing disposed on the dummy head and disposed opposite to the honing grindstone mounted on the honing tool inserted into the dummy head with a gap interposing a conductive liquid;
A liquid supply means for supplying a conductive liquid into the dummy head;
Voltage application means for applying a voltage to the honing grindstone and the electrode for electrolytic dressing,
An inner peripheral surface of a cylinder bore characterized in that the honing grindstone and the electrolytic dressing electrode facing each other in the presence of the conductive liquid supplied by the liquid supply means are applied with voltage by the voltage applying means to electrolytically dress the honing grindstone. Honing method. The inner peripheral surface of the cylinder bore of the cylinder block is honed with a honing tool that is inserted through a cylindrical dummy head mounted on the upper deck of the cylinder block and equipped with a honing grindstone with abrasive grains fixed by a conductive joint. In the honing device for the cylinder bore inner peripheral surface,
An electrode for electrolytic dressing disposed on the dummy head and disposed opposite to the honing grindstone mounted on the honing tool inserted into the dummy head with a gap interposing a conductive liquid;
A liquid supply means for supplying a conductive liquid into the dummy head;
Voltage application means for applying a voltage to the honing grindstone and the electrode for electrolytic dressing,
An inner peripheral surface of a cylinder bore characterized in that the honing grindstone and the electrolytic dressing electrode facing each other in the presence of the conductive liquid supplied by the liquid supply means are applied with voltage by the voltage applying means to electrolytically dress the honing grindstone. Honing processing equipment.   The honing apparatus for an inner peripheral surface of a cylinder bore according to claim 3, wherein electrolytic dressing is performed every time a honing tool passes through the dummy head.   4. The honing apparatus for an inner peripheral surface of a cylinder bore according to claim 3, wherein electrolytic dressing is performed every preset number of honing processes. The honing tool includes the rod-shaped honing grindstones arranged radially on the outer periphery of a honing tool main body that is supported and rotated by the main shaft,
4. The electrolytic dressing electrode has a cylindrical shape that allows insertion of a honing tool main body and a honing grindstone supported by a main shaft, and is opposed to each honing grindstone at an interval. The honing apparatus of the cylinder bore inner peripheral surface of any one of -5. The honing tool includes the rod-shaped honing grindstones arranged radially on the outer periphery of a honing tool main body that is supported and rotated by the main shaft,
The electrode for electrolytic dressing is a plurality of electrodes that are radially arranged to allow the insertion of a honing tool body and a honing grindstone supported by a main shaft and to face each honing grindstone at an interval. The honing apparatus for a cylinder bore inner peripheral surface according to any one of claims 3 to 5, wherein

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