Method for impregnating porous grinding wheels with adhesive

Abstract

This invention relates to a porous grinding wheel that has improved mechanical toughness and water permeability, as porous grinding wheels, which cool both the outer circumference of the grinding wheel and the grinding surface of the workpiece, have poor mechanical toughness. [Solution] In a porous grinding wheel U, an adhesive 4 is continuously impregnated into each abrasive grain 3 by penetrating or pressurizing it from the center of the grinding wheel's rotation axis toward the outer circumference, thereby adding and forming a pressure-resistant and highly tough structural material H, and reinforcing fiber threads S of about 1 cm are kneaded into the grinding wheel to create a porous grinding wheel.

Description

Technical Field

[0004]

[0001] The present invention relates to a grinding wheel used for grinding a workpiece to be ground. In order to enhance the positive cooling effect on the grinding surface of the workpiece to be ground and the positive cooling effect on the outer peripheral surface of the grinding wheel, cooling water is fed into the grinding wheel from the central part of the grinding wheel, and the abrasive grain gaps in the grinding wheel are radially radiated and cooled in the outer peripheral direction by the high-speed rotation of the grinding wheel, and at the same time, the outer periphery of the grinding wheel and the grinding surface of the workpiece to be ground are cooled. The present invention relates to an innovative new technology of a porous grinding wheel.

Background Art

[0002] In recent years, in order to enhance the positive cooling effect on the grinding surface of the workpiece to be ground and the positive cooling effect on the outer peripheral surface of the grinding wheel, cooling water is fed into the grinding wheel from the central part of the grinding wheel, and the inside of the grinding wheel is radially cooled in the outer peripheral direction by the high-speed rotation of the grinding wheel, and at the same time, the outer periphery of the grinding wheel and the grinding surface of the workpiece to be ground are cooled. A porous grinding wheel is provided.

[0003] One of the specific porous grinding wheels is disclosed in Japanese Patent Application Laid-Open No. 2011-224764. The outline configuration is such that a low-temperature cooling gas or high-pressure coolant penetrates and jets from the central inside to the outer peripheral surface of a grinding wheel, a polishing buff, etc. to directly cool the processing point, and the cooling gas or high-pressure coolant is efficiently concentrated and jetted to the processing point. The specific configuration includes a disk-shaped processing means such as a grinding wheel with good air permeability or an electrodeposited grinding wheel provided with an air circuit and a liquid circuit in a metallurgical part, a buff, etc., and the above processing means penetrates through a through hole made in a coupler engaged with a flange engaged with a rotating spindle on the rotation center side to supply cooling gas to the processing point at the outer peripheral edge part from the inside, and a cylindrical cover body that surrounds the above processing means and has an opening for concentrating and guiding the cooling gas jetted from the outer peripheral edge part to the processing point on the grinding surface of the workpiece. [See Patent Document 1.]

[0004] Furthermore, this grinding wheel is constructed by joining a grinding wheel disc with a high abrasive density and a grinding wheel disc with a low abrasive density. The two high-density grinding wheel discs sandwich the low-density grinding wheel disc between them on both sides. Grinding fluid or cooling airflow is introduced from the center of the rotating shaft supporting the three grinding wheel discs, penetrating into the low-density grinding wheel disc and ejecting it towards its outer surface. [See Patent Document 2.]

[0005] Furthermore, there are cylindrical resin grinding wheels with enhanced water permeability within the wheel. These cylindrical resin grinding wheels have high water resistance because the resin binder in the grinding wheel pieces is composed of phenolic resin, offering the advantage of providing a large amount of grinding fluid to the grinding surface. [See Patent Document 3.]

[0006] [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2011-224764 [Patent Document 2] Utility Model Registration No. 3172625 [Patent Document 3] Japanese Patent Publication No. 2004-337986 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Japanese Patent Publication No. 2011-224764, mentioned in Patent Document 1 above, relates to the present inventor's invention, which involves directly cooling the machining point by permeating and ejecting a low-temperature cooling gas or high-pressure cooling liquid from the central interior to the outer circumferential surface. While this allows the cooling gas or high-pressure cooling liquid to be efficiently concentrated and guided to the machining point, the invention recognizes that the bubble-shaped grinding wheel or electroplated grinding wheel is made by joining multiple arc-shaped bodies to form a disc, resulting in poor mechanical durability during high-speed rotation of the grinding wheel. Furthermore, the supply and means of cooling gas or high-pressure cooling liquid to the center of the grinding wheel are complicated, leaving an unstable element in the effect of directly cooling the machining point by permeating and ejecting a low-temperature cooling gas or high-pressure cooling liquid from the central interior to the outer circumferential surface.

[0009] The above-mentioned Patent Document 2, Utility Model Registration No. 3172625, also relates to the present inventor's invention, and directly cools the machining point by permeating and ejecting a low-temperature cooling gas or high-pressure cooling liquid from the central interior to the outer surface. However, it has a simplified joint structure in which a single grinding wheel disc with low grinding wheel density is sandwiched on both sides, so it cannot efficiently and evenly guide the cooling gas or high-pressure cooling liquid to the entire surface of the machining point of the workpiece at all times.

[0010] Patent Publication No. 2004-337986, mentioned in Patent Document 3 above, has the disadvantage that, because the resin binder of the abrasive fragments is made of phenolic resin, when grinding hard materials, strong grinding resistance occurs, causing the resin binder of the abrasive fragments to deform, making them prone to falling off and resulting in a short lifespan.

[0011] The inventor of this application has conducted sincere research and prototype testing to completely resolve the problems in the conventional processing control devices and grinding wheels mentioned above. As a result, grinding wheels have countless combinations of the three elements: abrasive grains, binders, and pores, resulting in an innumerable number of possible combinations. Moreover, grinding wheels in which these three elements are uniformly (fired) formed, and which have a particularly high porosity, are weak against impacts in the direction of rotation and are prone to cracking. Therefore, we focused on the water retention properties of the pores in grinding wheels, and also discovered that impregnating the grinding wheel with adhesive after molding improves its impact resistance. [Means for solving the problem]

[0012] The porous grinding wheel of claim 1, which solves the above objective, is a porous grinding wheel that, in order to enhance the active cooling of the grinding surface of the material to be abraded and the active cooling effect on the outer surface of the grinding wheel, sends cooling water into the grinding wheel from the center of the grinding wheel, and radiates the gaps between the abrasive grains inside the grinding wheel radially toward the outer surface by high-speed rotation of the grinding wheel, and cools the outer surface of the grinding wheel and the grinding surface of the material to be abraded, A porous grinding wheel characterized by forming a pressure-resistant, high-toughness structural material by continuously impregnating each abrasive grain with adhesive by permeating or pressurizing it from the center of the grinding wheel's rotation axis toward the outer circumference, and by kneading in reinforcing fiber pieces of about 1 cm in size.

[0013] The porous grinding wheel of claim 2 is characterized in that the bone structure material of claim 1 is made of a color-identifiable material and the limit outer diameter of the grinding wheel wear, which gradually wears down, is indicated.

[0014] The porous grinding wheel of claim 3 is characterized in that, with respect to the adhesive of claim 1, it is made of any of the following: emulsion-type adhesive, organic solvent-type adhesive, solvent-free adhesive, resin / rubber, etc., and is liquid in which the adhesive strength, flexibility, and water resistance functions are optimally selected for each application.

[0015] The porous grinding wheel of claim 4 is characterized in that the adhesive of claim 1 is composed of any of acrylic adhesive, urethane adhesive, or silicone adhesive, including caulking material and sealing material.

[0016] The porous grinding wheel of claim 5 is characterized in that, with respect to the bone structure material of claim 1 or 2, the shape of the bone structure, the number of bone structures, and the surface volume of the bone structure are optimally selected according to the intended use.

[0017] The method for impregnating a porous grinding wheel with adhesive, characterized in that the porous grinding wheel according to claim 6 is reinforced and molded by impregnating the side surface of the grinding wheel with the adhesive using a syringe-like sprayer.

[0018] The porous grinding wheel according to claim 7 is characterized in that, in the method for impregnating the adhesive of the porous grinding wheel according to claim 6, the injector attached to the robot arm applies the adhesive to the grinding wheel surface in an arbitrary shape pattern by NC control.

Advantages of the Invention

[0019] According to the porous grinding wheel of claim 1, since the adhesive for each abrasive grain is infiltrated or pressurized from the center of the grinding wheel rotation axis toward the outer periphery and continuously impregnated, a pressure-resistant and highly tough bone structure material is formed. Also, since fiber pieces of about 1 cm for reinforcement are kneaded, even during the grinding impact on the grinding wheel or during the grinding operation under an overload condition, grinding wheel breakage is reduced or eliminated, and improvement in grinding processing and high-precision grinding during the grinding operation become possible.

[0020] According to the porous grinding wheel of claim 2, since the bone structure material of claim 1 is made of a grinding wheel of a material whose wear state and grinding type can be color-identified, the wear state of this grinding wheel and the classification of the grinding type can be easily discriminated. Thus, the discrimination of the grinding wheel according to the material of the workpiece and the polishing accuracy is accurate and easy, and there is no overuse of the wrong grinding wheel or misselection of the grinding wheel.

[0021] According to the porous grinding wheel of claim 3, since the adhesive is selected from any of emulsion-type adhesives, organic solvent-type adhesives, solvent-free adhesives, resins, rubbers, etc., an optimal porous grinding wheel with functions of adhesiveness, flexibility, and water resistance in a liquid state can be made for various different materials of the workpiece and each use purpose, and it can be arbitrarily selected.

[0022] According to the porous grinding wheel of claim 4, since the adhesive is selected from any of acrylic adhesives, urethane adhesives, and silicone adhesives including caulking materials and sealing materials, an optimal porous grinding wheel with functions of adhesiveness, flexibility, and water resistance in a liquid state can be made for various different materials of the workpiece and each use purpose, and it can be arbitrarily selected.

[0023] According to the porous grinding wheel of claim 5, since the shape, number, and volume of the bone structure are optimally selected according to the intended use, a porous grinding wheel corresponding to various different and diverse workpieces to be ground can be arbitrarily manufactured, so its versatility becomes diverse.

[0024] In the manufacture of the porous grinding wheel of claim 6, in the bone structure material of claim 1 above, since the impregnation method of impregnating the bone structure material with the adhesive by an injector in the shape of a syringe is adopted, the manufacturing process can be simplified, and the arrangement and distribution of the adhesive in the porous grinding wheel can be diversified, and a porous grinding wheel corresponding to various workpieces to be ground can be made inexpensive and mass-produced.

[0025] In the manufacture of the porous grinding wheel of claim 7, in the impregnation method of impregnating the bone structure material with the adhesive by the injector of claim 6 above, the step of attaching the injector to a robot arm and applying the adhesive to the grinding wheel surface in an arbitrary shape pattern by NC control can be fully automated.

Brief Description of the Drawings

[0026] [Figure 1] It shows an embodiment of the present invention and is an explanatory diagram of a porous grinding wheel with resin structure reinforcement. [Figure 2] It shows an embodiment of the present invention and is a classification diagram in which the characteristics of various adhesives are charted. [Figure 3] It shows an embodiment of the present invention and is a perspective view for explaining a method of manufacturing a porous grinding wheel. [Figure 4] It shows an embodiment of the present invention and is a partial microstructure diagram in which the microstructure of a porous grinding wheel is enlarged. [Figure 5] It is a cooling action diagram during grinding showing the grinding action of a conventional grinding wheel and the porous grinding wheel of the present invention. [Figure 6] It is a partial microstructure diagram in which the microstructure of a porous grinding wheel is enlarged.

Modes for Carrying Out the Invention

[0027] The porous grinding wheel of the present invention and its manufacturing method will be described sequentially below with reference to Figures 1 to 6. [Examples]

[0028] First, Figure 5 shows the cooling state "External" for the grinding surfaces of each abrasive material W1 and W2 and the grinding point of the grinding wheel using a conventional external nozzle, and the cooling state "Internal" for the grinding surface of the abrasive material W and the grinding point of the grinding wheel using the porous grinding wheel U of the present invention. In the "External" cooling state "External" using a conventional external nozzle N, the cooling effect of the cooling water W0 on the grinding surface of the abrasive material W and the grinding point of the grinding wheel is poor, and little cooling effect is obtained. In contrast, with the porous grinding wheel U of the present invention, the cooling effect of the cooling water W0 on the grinding surface of the abrasive material W and the grinding point of the grinding wheel is perfect, and a high cooling effect is obtained on both, resulting in a high-precision grinding surface and a grinding wheel with an extremely long lifespan.

[0029] Next, the porous grinding wheel U of the present invention will be described in detail with reference to Figures 1 to 4. First, in Figure 1, the porous grinding wheel U exhibits the structure of a vitrified grinding wheel reinforced with a resin "bone" structure in which adhesive 2 is injected and fixed into the gaps between the abrasive grains of the grinding wheel. That is, the porous grinding wheel U described above consists of abrasive grains (grains that cut materials) 3, adhesive (bonding agent that connects the abrasive grains) 4, and pores 5 that form gaps between the abrasive grains (promoting chip removal and cooling of the abrasive grains). The porous grinding wheel U described above consists of a shaft cylinder 1, a grinding wheel body 2, and adhesive 4 that has permeated the radially formed abrasive grains 3.

[0030] As shown in Figure 2, typical adhesives 4 include vitrified V, resinoid B, rubber R, metal M, etc. Their respective properties are explained in Figure 2. The choice of adhesive depends on the specific characteristics required by the various porous grinding wheels U. In other words, Vitrified V uses feldspar and other inorganic clays as binders, is highly resistant to water, chemicals, and heat, can withstand long-term storage, and is typically fired at temperatures of 1200°C to 1300°C. Resinoid B, also known as the Bakelite method, uses carbolic acid and formalin-based synthetic resins as binders, offering excellent elasticity and toughness, high safety, and the ability to be used at high speeds. Rubber® uses natural or artificial rubber as a binder, is highly elastic and strong, and has a smooth finish, but is susceptible to heat and oil. Metal M uses metals such as silver, copper, and nickel as binders and has the strongest bonding strength. It is mainly used as a binder for diamond and CBN.

[0031] Next, the method for manufacturing the porous grinding wheel U, which is central to the present invention, and the porous grinding wheels U1 to U3, each consisting of a different microstructure produced by this manufacturing method, will be described in order below.

[0032] First, the manufacturing method of the porous grinding wheel U is shown in Figures 3 and 4. As can be seen in the enlarged view of the porous grinding wheel U in Figure 4, when a large number of abrasive grains (for example, diamond 3) are mixed with a binder (any of vitrified V, resinoid B, rubber R, metal M, etc.) 4 and placed in a mold (not shown) and compressed, a strong grinding wheel with distributed air bubbles K is formed.

[0033] In this manufacturing method, in order to further enhance the intergrain bonding and strengthen the formation of pores K, as shown in the enlarged partial views of Figures 4 and 6, fiber threads S are intertwined with each abrasive grain 3 and mixed into the gaps of these pores K, thereby firmly bonding the abrasive grains together. As described above, the porous grinding wheel U, formed into a structure 3A in which fiber threads S are intertwined with each abrasive grain 3, is produced and manufactured by the method of the basic principle shown in Figure 3.

[0034] In Figure 3 above, first, adhesive 4 is continuously impregnated onto each abrasive grain 3 of the porous grinding wheel U from the axial side toward the outer diameter or in the opposite direction to form a pressure-resistant, high-toughness structural material H··, and a porous grinding wheel U is manufactured by kneading in reinforcing fiber threads S of approximately 1 cm in length. Furthermore, the detailed structure of the porous grinding wheel U is shown in the enlarged view in Figure 6, where countless abrasive grains 3 are attached to the fiber threads S, and these multiple fiber threads S are intertwined, forming countless pores K·· in the gaps between the countless abrasive grains 3. As a result, abrasive grain detachment is prevented, the durability of the grinding ability is maintained, and the pores K·· formed within the grinding wheel are not destroyed by the grinding action.

[0035] The specific manufacturing method for the above-mentioned porous grinding wheel U is as follows: An adhesive 4, including the above-mentioned caulking material / sealing material, is applied radially to one side of the porous grinding wheel U using a syringe-like sprayer 10, as shown in the diagram. When applied radially in four directions at 45° intervals, the adhesive 4 is applied and penetrated radially in eight directions, resulting in a porous grinding wheel U1 with a pressure-resistant and high-toughness structural material H. Of course, it is also applied to the same position on the back side. The sprayer 10 is attached to the tip of a robot hand (not shown), and under robot control, the adhesive 4 is penetrated or pressurized from the center of the rotation axis toward the outer circumference, continuously impregnating to form a pressure-resistant and high-toughness structural material H, and is also applied in an arbitrary pattern mixed with reinforcing fiber threads S of approximately 1 cm in length.

[0036] Therefore, a porous grinding wheel U2 with adhesive 4 broadly applied and permeated radially, or a porous grinding wheel U3 with adhesive 4 broadly applied and permeated circumferentially towards the center of the porous grinding wheel can be arbitrarily obtained. The above three coating patterns are illustrated as three examples, and a wide variety of coating patterns can be selected.

[0037] Furthermore, the robotic control of the sprayer 10 attached to the tip of a robot hand (not shown) allows for the application of adhesive to the grinding wheel surface in any shape pattern using NC control. Similarly, a three-dimensionally controlled machine tool can also apply adhesive 4 to the sides of the porous grinding wheels U1 to U3 in any shape pattern.

[0038] Therefore, by impregnation methods in which adhesive 4 is formed on porous grinding wheels U1 to U3 that use adhesive as a structural material, the above-mentioned porous grinding wheels corresponding to various workpiece materials W (shown in Figure 2) can be mass-produced at low cost.

[0039] Furthermore, in the porous grinding wheels U1 to U3 described above, when cooling water is sent into the grinding wheel from the center, the high-speed rotation of the grinding wheel radiates cooling the gaps between the abrasive grains (pores K) in the grinding wheel outward, and also cools the outer circumference of the grinding wheel and the grinding surface of the material to be abrasive W. In the porous grinding wheels U1 to U3, the active cooling of the cooling water to the grinding surface of the material to be abrasive W and the active cooling effect on the outer surface of the grinding wheel are enhanced.

[0040] Furthermore, since reinforcing fiber pieces S approximately 1 cm in length are kneaded into the porous grinding wheels U1 to U3, the adhesive 4 is continuously impregnated to each abrasive grain 3 by permeating or pressurizing it from the center of the grinding wheel's rotation axis toward the outer circumference. This forms a pressure-resistant and highly tough structural material, and also increases the flow rate of the cooling water W0 sprayed in the outer diameter direction within the porous grinding wheels U1 to U3, dramatically improving the cooling effect on the grinding surface of the workpiece W. In addition, the shedding of abrasive grains 3 due to the grinding action can be suppressed, resulting in a longer lifespan for the grinding wheel, suppression of a decrease in grinding capacity, and the ability to maintain high grinding performance. [Industrial applicability]

[0041] The porous grinding wheel of the present invention can be widely applied to grinding flat and curved workpieces, such as plate-shaped materials and arc-shaped materials, used in various product devices. [Explanation of Symbols]

[0042] 3 abrasive grains 3A Organization 4. Adhesive 10 injector S fiber yarn M Metal R Rubber V Vitrified H Bone structure material U(U1~U3) Porous grinding wheel W Workpiece material W1, W2 Workpiece W0 Cooling water

Claims

1. In a porous grinding wheel, in order to enhance the active cooling of the grinding surface of the workpiece and the active cooling effect on the outer surface of the grinding wheel, cooling water is sent into the grinding wheel from the center, and the gaps between the abrasive grains inside the grinding wheel are radiatedly cooled outward by the high-speed rotation of the grinding wheel, while cooling the outer surface of the grinding wheel and the grinding surface of the workpiece, A porous grinding wheel characterized by forming a pressure-resistant, high-toughness structural material by continuously impregnating each of the above-mentioned abrasive grains with an adhesive by permeating or pressurizing it from the center of the grinding wheel's rotation axis toward the outer circumference, and by kneading in reinforcing fiber pieces of about 1 cm in length.

2. A porous grinding wheel according to claim 1, characterized in that the bone structure material is made of a color-identifiable material and the limit outer diameter of the grinding wheel wear, which gradually wears down, is indicated.

3. The adhesive for the porous grinding wheel according to claim 1 above is made of any of the following: emulsion-type adhesive, organic solvent-type adhesive, solvent-free adhesive, resin / rubber, etc., and is liquid in form, with optimal selection of adhesive strength, flexibility, and water resistance for each grinding application.

4. The porous grinding wheel according to claim 1 above is characterized in that the adhesive comprises one of an acrylic adhesive, a urethane adhesive, or a silicone adhesive, including caulking material and sealing material.

5. The porous grinding wheel according to claim 1 or 2 above is characterized in that the bone structure material of the porous grinding wheel is selected to an optimal value according to the grinding purpose of the material to be abraded, such as the shape of the bone structure, the number of bone structures, and the surface volume of the bone structure.

6. The method for impregnating a porous grinding wheel with adhesive, characterized in that the structural frame material of the porous grinding wheel according to claim 1 above is reinforced and molded by continuously impregnating the side surface of the grinding wheel with the adhesive using a syringe-like sprayer.

7. The method for impregnating a porous grinding wheel with adhesive according to claim 6 above is characterized in that the sprayer, which is attached to a robot arm, applies adhesive to the grinding wheel surface in an arbitrary shape pattern by NC control.

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