JPH06155293A - Grinding working method for workpiece and device therefor - Google Patents

Abstract

PURPOSE:To provide the cutting and grinding work for ceramics, metal, plastics or the composite body of these materials, with high quality and high efficiency, in the cutting and grinding work by using a rotary grinding wheel which is formed trough metal-bonding the diamond abrasive grains thereon. CONSTITUTION:A flange part 2 and a cylinder part 3 having a small diameter are coaxially arranged on one edge side, and a ring shaped working rotary grinding wheel 10 is insertion-fitted into the cylinder part 3 of a fixing flange member 1 which is fixed on a rotary shaft 5 by a bolt, and fixed by a tightening metal fitting 7 screwed with the outer peripheral surface of the cylinder part through a tightening flange 6, and liquid flow grooves 11 are arranged at a place or plural places ranging from the center side to the circumference edge surface on both the surfaces of the grinding wheel 10. The liquid flow grooves are connected to a cooling medium feeding source through a liquid flow hole 4 formed on the cylinder part 3, and the cooling medium mixed with the fine isolated abrasive grains having an average particle diameter of 0.005-50mum is jetted to the contact part of a workpiece 20 by the centrifugal force in revolution.

Description

Detailed Description of the Invention

[0001]

This invention relates to ceramics, metals and alloys or plastics and composites thereof,
According to the improvement of the method of grinding with a grinding machine that has a rotating grindstone for coating with adhered abrasive grains, a specific fine free abrasive grain is provided by providing a liquid passage groove on the circumferential end surface where the abrasive grains of the rotary grindstone are coated and adhered. TECHNICAL FIELD The present invention relates to a grinding method of a work material and a device therefor capable of supplying a cooling medium mixed with iron to a working point of contact processing and realizing high-quality and high-efficiency grinding.

[0002]

_2. Description of the Related Art Conventionally, Al ₂ O ₃ based or ZrO ₂ based substrates for magnetic heads, or optical ceramics such as PLZT used for displays and optical shutters,
Alternatively, work materials such as magnetic metal products such as rare earth magnets are manufactured by molding and sintering raw material powders by the powder metallurgy method. In many cases, it is difficult to manufacture, and therefore, a part or the whole surface of the material is subjected to forming processing such as cutting or grinding.

Generally, a rotary grindstone in which diamond abrasive grains are metal-bonded is widely used for forming the workpiece, and the abrasive grain surface is brought into rotary contact with the workpiece to perform grinding.

[0004]

The rotary grindstone to which the diamond abrasive grains are metal-bonded, the abrasive grains are crushed or clogged with the progress of machining such as cutting and grinding, resulting in chipping and process-altered layers. Interrupt the cutting and grinding work,
Needs to be dressed mechanically.

Further, the smaller the abrasive grain size of the diamond abrasive grains and the larger the amount of cutting and grinding per unit time, the more the grinding stones are crushed and clogged, and the dressing time and incidental work are increased to increase the productivity. There was a problem that hindered.

The present invention solves the above problems of the conventional method of cutting and grinding with a rotary grindstone in which diamond abrasive grains are metal-bonded, and has high quality and high efficiency of ceramics, metals and plastics or composites thereof. The purpose of the present invention is to provide a grinding method capable of cutting and grinding and a device therefor.

[0007]

SUMMARY OF THE INVENTION The present invention rotates a grinding machine having a rotating grindstone for processing in which abrasive grains are applied and fixed to the circumferential end surface and a required portion, and the abrasive grain surface is brought into rotary contact with a workpiece. In the grinding method of the workpiece to be ground, one or more liquid passage grooves from the center side of the rotating grindstone for processing to the circumferential end surface are arranged on one side or both sides and communicated with the liquid passage groove. The liquid passing holes are arranged in the grinding apparatus and connected to the supply source of the cooling medium, and the fine free abrasive grains having an average particle diameter of 0.005 μm to 50 μm are discharged from the liquid passing groove by the centrifugal force during the rotation of the rotary grindstone. It is a method of grinding a work material, characterized in that the work material is ground while jetting a mixed cooling medium.

According to the present invention, a fixing flange member having a flange portion and a cylindrical portion having a diameter smaller than that coaxially arranged on one end side is fixed to the other end to rotatably support a rotary shaft, and the fixing flange member. Insert the ring-shaped rotating grindstone with abrasive grains applied and fixed to the circumferential end surface and the required part on the cylindrical part of
Further, the rotary grindstone is fixed by a clamp fitting that is screwed onto the outer peripheral surface of the cylindrical portion via a ring-shaped tightening flange, and one or more passages from the center side of the rotary grindstone to the circumferential end surface are provided. The liquid groove is provided on one side or both sides, and the liquid passage hole communicating with the liquid passage groove is arranged in the grinding processing device, and the average particle diameter is 0.005 μm from the liquid passage groove due to the centrifugal force during the rotation of the rotary grindstone. A grinding processing apparatus for a work material, characterized in that a cooling medium mixed with fine free abrasive grains of ˜50 μm can be jetted.

In the present invention, the material to be processed is Al
All materials that require cutting and grinding, such as magnetic head substrates such as ₂ O ₃ and ZrO ₂ systems, optical ceramics such as PLZT, metals and alloys such as rare earth magnets, plastics plates and composites thereof. Includes. Further, as the abrasive grains of the processing rotary grindstone, any one may be used as long as it is a hard abrasive grain, but in general, a rotary grindstone in which diamond abrasive grains having an average grain size of 1 μm to 200 μm are metal-bonded to a required surface and applied and fixed is used. preferable.

In the present invention, water is used as the cooling medium,
An organic solvent is preferable, and free abrasive grains mixed in the cooling medium include SiO ₂ having an average particle size of 0.005 μm to 50 μm,
Al ₂ O ₃ , MgO, CeO ₂ , diamond fine powder 1w
It is preferable to mix t% to 20 wt%. The average particle size of loose abrasive grains is 1 / the average particle size of the abrasive grains that make up the grindstone.
It is preferably about 2 to 1/200. In the present invention, if the amount of the free grindstone mixed into the cooling medium is less than 1 wt%, the effect of mixing the free abrasive grains cannot be obtained, and if it exceeds 20 wt%, it is difficult to obtain the balance of the flange, and the precipitation grains cause the supply of the cooling medium. This is not preferable because it may clog the parts. Further, the injection amount of the cooling medium greatly varies depending on the grinding conditions such as the grindstone grain size, the cutting depth, and the feed rate, and the purpose of grinding, so it may be appropriately selected depending on the grinding condition and purpose of grinding.

An example of a grinding apparatus according to the present invention is shown in FIG.
Based on. The fixing flange member 1 having the shaft core portion bolted to the rotary shaft 5 has a flange portion 2 on one end side.
And a cylindrical portion 3 having a smaller diameter than that, arranged coaxially, and the rotation shaft is driven to rotate by a motor (not shown).
A ring-shaped processing grindstone 10 having abrasive grains applied and fixed to the circumferential end surface and a required portion is inserted into the cylindrical portion 3 of the fixing flange member 1, and further, the ring-shaped tightening flange 6 is provided to the outer peripheral surface of the cylindrical portion. The rotary whetstone 1 is fixed by a tightening metal fitting 7 that is screwed. The machining rotary grindstone 10 is provided with one or a plurality of liquid passage grooves 11 extending from the center side to the circumferential end face on both surfaces thereof, and the liquid passage groove 11 and the liquid passage holes 4 provided in the cylindrical portion 3. , And the liquid passage hole 4 is connected to a supply source of a cooling medium (not shown) in the cylindrical portion 3. With the above configuration, the cooling medium mixed with the fine free abrasive grains having an average particle size of 0.005 μm to 50 μm passes from the supply source through the liquid passage hole 4 by the centrifugal force during the rotation of the rotary grindstone 10 and the liquid passage groove. It is jetted from 11.

Cooling in which free grinding particles having a specific average particle diameter are mixed with respect to the processing work point by coming into contact with the surface of the workpiece 20 to be transferred while rotating the processing rotary grindstone 10 of the grinding apparatus according to the present invention. The medium is jetted to grind, but normally, the rotating grindstone 10 for processing and the workpiece 20 are processed by the external nozzle 30.
It is not necessary to inject the cooling medium toward the contact part of
Depending on the grinding conditions, in addition to preventing heat generation of the rotary grindstone 1 due to cutting and grinding, it is possible to prevent the abrasive grains of the rotary grindstone 1 from falling off and to suppress abnormal wear, and to prevent cutting burn, chipping occurrence and work-affected layer formation, an external nozzle. It is preferable to inject the cooling medium from 30 toward the contact portion.

[0013]

As a result of various studies to solve the problems of the conventional cutting and grinding methods, the inventor forced the cooling medium to the working point where the abrasive grains forming the working grindstone interfere with the workpiece. We have found a specially designed grinding tool for supply,
By using the grinding apparatus, fine free abrasive grains having a specific average particle size are mixed in a cooling medium, and are jet-cooled to the working point, and, if necessary, a rotary grindstone for processing and a workpiece. By spraying cooling water or organic solvent or the same cooling medium sprayed from the grinding machine from an external nozzle to the contact part with the material, the abrasive grains constituting the grindstone are exfoliated and abnormal due to heat generation by cutting and grinding. It is possible to suppress abrasion, reduce grinding burn, chipping, and generation of a work-affected layer as much as possible, and perform processing such as cutting and grinding with high efficiency.

In particular, according to the present invention, the amount of protrusion of the abrasive grains constituting the grindstone can be apparently reduced by the fine free abrasive grains mixed in the cooling medium sprayed from the grinding tool, and the bond material in the grindstone is processed. According to the grinding force, there is an effect that the amount of protrusion of the abrasive grains for shaving is appropriately kept constant, and an effect that the grindstone bond material and chips are prevented from adhering to the grindstone surface.

[0015]

【Example】

Example 1 Using the grinding apparatus according to the present invention shown in FIG. 1 as described above, as a material to be processed, a dimension length 40 mm × width 40 mm × thickness 2.8.
A ceramic plate composed of 70 atomic% of Al ₂ O _{3 and} 30 atomic% of Tic was processed to have a groove depth of 1.0 mm and a groove width of 1.2 mm. The rotary grindstone for processing at that time uses diamond abrasive grains having an average particle diameter of 20 μm as the abrasive grains, and has a ring-shaped dimension of outer diameter 100 mm × inner diameter 50 mm × thickness 1.2 mm.
Met. Six liquid passages each having a width of 4.0 mm and a depth of 0.3 mm were submerged in the end face of the rotary grindstone for processing. Rotational speed of rotating grindstone for processing 8000 rpm, moving speed of workpiece 20
SiO ₂ with an average particle size of 3 μm
Coolant mixed with 5 wt% of fine powder as free abrasive grains in cooling water is jetted to the working point at a flow rate of 1.5 l / min, and a flow rate of 4 l / min from the external nozzle to the contact area between the grindstone and the workpiece. Grinding was performed while spraying. No chipping occurred in the obtained groove portion, and an increase in grinding resistance value with the progress of grinding was suppressed, and the dressing interval could be lengthened. As a result of observing the surface condition of the grindstone as the grinding progressed, the protrusion of the abrasive grains was kept constant without any crushing by the bonding agent in the grindstone.

[0016] using a grinding machining apparatus according to the present invention of Figure 1 Example 2 described above, PLZT material as a workpiece (62ZrO ₂ -38TiO ₂ -
Dimensions of 9LaO-91PbO ₂₎ length 100 mm x width 50
A groove having a groove depth of 120 μm and a groove width of 0.6 mm was processed on a test piece having a size of mm × 0.5 mm. At that time, the rotary grindstone for processing uses diamond abrasive grains having an average particle diameter of 20 μm as abrasive grains, and has a ring-shaped dimension of outer diameter 100 mm × inner diameter 50 mm ×
The thickness was 0.6 mm. Six liquid passage grooves each having a width of 4.0 mm and a depth of 0.2 mm were submerged in the end face of the rotary grindstone for processing at 6 positions. The rotation speed of the rotating grindstone for processing is 30,000 rpm, the moving speed of the work material is 300 mm / min, and the cooling medium is made by mixing 5 wt% of SiO ₂ fine powder with an average particle diameter of 3 μm as free abrasive particles into cooling water. 1 l / mi to the point
Grinding was performed while spraying at a flow rate of n and spraying from an external nozzle to the contact portion between the grindstone and the workpiece at a flow rate of 1 l / min. No chipping occurred in the groove portion of the obtained work material, and there were few processing strain layers generated in the bottom and side portions of the grinding groove, and the grindstone surface condition did not change from the initial condition even after the processing progressed. .

Example 3 Using the grinding apparatus according to the present invention shown in FIG. 1 as described above, a test piece of Nd15at% -B7at% -Fe residual magnet having a length of 10 mm, a width of 20 mm and a thickness of 20 mm was used as a material to be processed. A groove having a groove depth of 10 mm and a groove width of 1.2 mm was processed. The rotating grindstone for processing at that time has an average grain size of 40 as abrasive grains.
Ring-shaped outer diameter 1 using diamond abrasive grains of μm
It was 00 mm × inner diameter 50 mm × thickness 1.2 mm. Six liquid passage grooves each having a width of 4.0 mm and a depth of 0.2 mm were submerged in the end face of the rotary grindstone for processing at 6 positions. The rotation speed of the processing grindstone is 8000 rpm, and the moving speed of the workpiece is 10 m / min.
At 5 liters, a cooling medium containing 5 wt% of SiO ₂ fine powder with an average particle diameter of 3 μm as free abrasive grains in cooling water was added to the working point.
Grinding was performed while jetting at a flow rate of / min and jetting at a flow rate of 20 l / min from the external nozzle to the contact portion between the grindstone and the workpiece. The groove of the obtained work material did not cause chipping, there was no grinding baking or sharp increase in grinding resistance value with the progress of grinding, and the chips of the work material did not adhere to the grindstone surface. In other words, stable processing could be maintained.

[0018]

According to the present invention, fine free abrasive grains having a specific average particle size are mixed in a cooling medium, and a contact portion between a rotary grinding stone for machining and a work material is contacted from a circumferential end surface of the rotary grinding stone for machining. By spray cooling to, and, if necessary, by spraying the same cooling medium of cooling water or an organic solvent or the above grinding machine from the external nozzle to the contact portion between the processing grindstone and the workpiece. Since the heat generated by cutting and grinding can suppress the shedding and abnormal wear of the abrasive grains that make up the grindstone, grinding burn and chipping, and the generation of work-affected layers can be reduced as much as possible to perform cutting and grinding with high efficiency. be able to.

[Brief description of drawings]

FIG. 1 is a partially longitudinal explanatory view showing an example of a grinding apparatus according to the present invention.

[Explanation of symbols]

 1 Fixed Flange Member 2 Flange Part 3 Cylindrical Part 4 Liquid Penetration Hole 5 Rotating Shaft 6 Tightening Flange 7 Tightening Metal Fitting 10 Rotating Grinding Stone for Processing 11 Liquid Groove 20 Work Material 30 External Nozzle

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C22C 38/00

Claims (2)

[Claims] 1. A work piece to be ground by rotating a grinding machine having a rotating grindstone for processing, in which abrasive grains are applied and fixed to a circumferential end face and a required portion, to bring the abrasive grain surface into rotary contact with the work piece for grinding. In the grinding method, one or more liquid passage grooves from the center side of the rotating grindstone for processing to the circumferential end surface are provided on one side or both sides, and a liquid passage hole communicating with the liquid passage groove is formed in the grinding device. And the average particle size of 0.
A method of grinding a work material, which comprises grinding a work material while jetting a cooling medium mixed with fine free abrasive grains of 005 μm to 50 μm. 2. A rotary shaft is fixed to the other end of a fixing flange member in which a flange portion and a cylindrical portion having a diameter smaller than that are coaxially arranged on one end side, and is rotatably supported by the fixing flange member. Insert a ring-shaped rotating grindstone with abrasive grains applied and fixed to the circumferential end surface and the required part, and further tighten the rotating grindstone with a tightening fitting that is screwed onto the outer peripheral surface of the cylindrical part via a ring-shaped tightening flange. It is configured to be fixed, and one or a plurality of liquid passage grooves from the center side of the rotary grindstone to the circumferential end face are arranged on one side or both sides, and a liquid passage hole communicating with the liquid passage groove is ground and machined. The average particle diameter is 0.005 μm to 5 from the liquid passage groove by the centrifugal force generated when the rotating grindstone is rotated.
A grinding apparatus for a work piece, which is capable of jetting a cooling medium mixed with 0 μm fine free abrasive grains.