JPH02256462A - Molding method for metal bond fine abrasive grain grindstone and molding device - Google Patents

Abstract

PURPOSE:To efficiently mold a grindstone when necessary by arranging a molding device constituted of a discharge machining electrode and a grinding means provided with the metal bond grindstone on a machine tool fitted with a grinding tool. CONSTITUTION:A pulse current is fed to a metal bond fine abrasive grain grindstone 80 and a discharge machining electrode 140, and the outer periphery of the grindstone 80 is discharge-molded. A current is fed to a metal bond grindstone 120 applied with electrolytic in-process dressing and the metal bond fine abrasive grain grindstone 80, the outer periphery of the roughly molded grindstone 80 is dressed and finish-molded into a mirror surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for forming a metal bond fine abrasive grindstone attached to a grinding tool of a machine tool.

[Prior Art] Generally, a metal bond grindstone 10 is formed by using a matrix 12 of a material mixed with cast iron or iron fibers and mixing abrasive grains 14 such as Danyamorad, as shown in the outline in FIG. It has a basic structure.

This metal bond grindstone 10 has a strong bonding force of the base material 12, so that it can firmly hold the abrasive grains 14 against the resistance applied to the abrasive grains 14 when the metal bond grindstone 10 grinds a workpiece. Even if the cutting edge of the abrasive grains wears out and the grinding resistance increases, there is a problem in that the so-called self-regeneration effect, in which the abrasive grains fall off and new abrasive grains appear on the surface 16 of the grindstone 10, is lacking.

Therefore, in the metal bond grindstone 10, the grinding surface 16
It is necessary to actively truing (shaping) and dressing (sharpening).

The present applicant has already proposed a technique using electrical discharge machining as a means for truing and dressing the metal bond grinding wheel 10 (Japanese Patent Application No. 194031/1982). Electric discharge machining is performed while flowing an electric discharge machining fluid between the metal bond grinding wheel 10 and the base material 12 on the surface 16 of the metal bond grinding wheel 10, so that new abrasive grains 14 appear on the surface of the grinding wheel.

When this electrical discharge machining using a graphite electrode is applied to a metal bonded fine abrasive grinding wheel in which the average particle diameter of the abrasive grains is several tens of micrometers or less, finishing electrical discharge machining must be performed to control the discharge marks to a few tens of Ijm or less. This results in the disadvantage that the processing time becomes extremely long.

[Problems to be Solved by the Invention] Therefore, the present invention improves the flatness of the surface and efficiently achieves effective truing and dressing when truing and dressing the grinding surface of a metal bond fine abrasive grindstone. The basic object is to provide a forming method, and a further object is to provide an apparatus for carrying out this forming method, in particular on one multifunctional machine tool.

[Means for Solving the Problems] In order to solve the above problems, the method for forming a fine abrasive grindstone of the present invention includes a step of cutting an electrode for electrical discharge machining on a machine tool, and a step of cutting an electrode for electric discharge machining on a machine tool. A process of electrical discharge machining and rough forming of a metal bonded fine abrasive grinding wheel using electrodes for electric discharge machining, and finishing forming and dressing of the metal bonded fine abrasive grinding wheel while applying electrolytic in-process dressing to the grinding means having the metal bonded grinding wheel. It has a process. In a forming device that implements this forming method on a multi-purpose machine tool, means for electric discharge machining and means for electrolytic in-process dressing are rationally arranged according to the model of the multi-purpose machine tool. .

[Function] By rough forming the grinding surface of the metal bond fine abrasive grinding wheel by electric discharge machining using each of the above means, and then achieving finish forming and dressing at the same time using the metal bond grinding wheel subjected to electrolytic in-process dressing. , high-precision molding can be completed efficiently.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the principle of the present invention, and a metal bond fine abrasive grinding wheel 20 has a structure in which fine abrasive grains 24 with an average particle diameter of several tens of degrees or less are embedded in a matrix 22 made of iron or the like. . To truing and dressing the surface 25 of the grinding wheel 20, first, as in the conventional process, a graphite electrode etc. (
(not shown), electric discharge machining is performed by applying a pulse voltage while rotating this graphite electrode together with the grindstone 20.

The grinding wheel surface 25 obtained by electrical discharge machining while rotating with this graphite electrode has only a shape machined to imitate the surface shape of the graphite electrode, and the flatness of one surface corresponds to the flatness of the graphite electrode. It is not an improvement compared to. Therefore, in the present invention, this electrical discharge machining corresponds to a step of rough shaping the surface of the grindstone.

Next, in the present invention, the surface 25 of the metal bond fine abrasive grindstone 20, which is the grindstone to be formed, is ground by a metal bond grindstone (not shown) having an electrolytic in-process dressing device instead of the graphite electrode to achieve smoothness. High mirror surface 25a
At the same time, the matrix of the surface 25a of the mirror-finished metal bond fine abrasive grinding wheel 20 is further ground to make the abrasive grains 24 protrude from the matrix 22 by about 1/3 of the average abrasive grain diameter, resulting in a surface 25b. form and complete the final dressing process.

The metal bond grindstone equipped with this electrolytic in-process dressing device grinds the surface of the metal bond fine abrasive grindstone 20, which is the grindstone to be formed, and performs finishing truing and dressing at the same time, but this is not shown in FIG. This is a conceptual diagram.

The electrolytic in-process dressing method is summarized in the second section.
As shown in the figure, the metal bond grindstone 3o is connected via an electrode 32 to the positive electrode of a power supply device 34 for electrolytic dressing. The negative electrode of the power supply device 34 is connected to the metal bond grindstone 3
communicates with an electrode 36 disposed close to the surface of 0,
Grinding fluid is supplied between the metal bond grindstone 30 and the electrode 36 through a nozzle 40 .

While the metal bond grindstone 30 grinds the opposing workpiece 45, the metal matrix, which is an electrolyte material, of the metal bond grindstone 30 is electrolyzed, and abrasive grains, which are a non-electrolyte material, protrude, thereby achieving electrolytic in-process dressing.

In the present invention, by using a metal bond grinding wheel subjected to electrolytic in-process dressing, and grinding the surface of the metal bond fine abrasive grinding wheel, which is the grinding wheel to be formed, with this metal bond grinding wheel, the surface accuracy is high and the quality is good. It is possible to obtain a metal-bond fine abrasive grinding wheel with a fine dressing.

That is, the method for forming the metal bonded fine abrasive grindstone of the present invention is as follows.

(1) A process of cutting an electrode for electrical discharge machining, (2) A process of roughly forming a metal bond fine abrasive grain grindstone, which is a grindstone to be formed, by electrical discharge machining, and (3) A process of roughly forming a metal bond fine abrasive grain grindstone, which is a grindstone to be formed. This process consists of the following steps: finishing the abrasive grindstone with a metal bond grindstone that has been subjected to electrolytic in-process dressing, and dressing it at the same time.

Next, an embodiment will be described in which the method for forming a metal bonded fine abrasive grindstone of the present invention is applied to a turning center type compound machine tool.

FIG. 3 shows an outline of an embodiment of the apparatus, in which a plurality of tools such as a cutting tool 60 and a grinding tool 70 are replaceably installed on the turret 50 side of the compound machine tool. The grinding tool 70 includes a grindstone shaft 74 driven by a motor 72,
A metal bond fine abrasive grindstone 80 is attached to the tip of the grindstone shaft 74.

On the other hand, the forming apparatus 100 of the present invention is disposed on the headstock side of the compound machine tool. This forming device can be arranged, for example, on the side of the tailstock opposite to the main shaft.

This molding apparatus 100 has a spindle 104 driven by a motor 102, and is provided with a graphite electrode 110 for electrical discharge machining and a metal bond grindstone 120 on the spindle 104. The graphite electrode 110 is attached to the spindle 104 via an electrically insulating material 112, and the metal bond grinding wheel 120 is also electrically insulated from the spindle 104 by suitable insulating means (not shown). A power source 140 for electric discharge machining and a power source 150 for electrolytic in-process dressing are attached to the forming apparatus 1100. The positive electrode side of the electric discharge machining electric @ 140 is connected to the metal bond fine abrasive grinding wheel 80 side which is insulatively attached to the grinding wheel shaft 74 via a line 141 and an electrode 142, and the negative electrode side is connected to a line 144 and an electrode 145.
It is connected to the graphite electrode 110 via. graphite electrode 110
A nozzle 147 is arranged near the nozzle 147 to supply electrical discharge machining fluid.

The positive side of the power supply 150 for electrolytic in-process dressing is connected to the metal bond grindstone 120 via a line 151 and an electrode 152, and the negative side is connected to an electrode 155 disposed opposite the metal bond grindstone 120 via a line 154. Connecting. A nozzle 157 is arranged near the electrode 155 to supply grinding fluid.

The outline of the configuration of this device is as above, and its operation will be explained next.

The cutting tool 60 is mounted on the tool rest 50 equipped with an automatic tool changer of the multitasking machine tool, and the outer circumferential surface of the graphite electrode 110, which is rotationally driven by the motor 102 of the forming device 100, is turned along the path P1. The grinding tool 70 is mounted on the tool rest 50, and the metal bond fine abrasive grindstone 80, which is the grindstone to be formed by the grinding tool, is brought close to the graphite electrode 110 as shown in the path P, and a predetermined gap is set between the two. do.

The grindstone shaft motor 72 is operated to drive the metal bond fine abrasive grindstone 80, and while supplying electrical discharge machining fluid from the nozzle 147, lines 141 and 1 are supplied from the electrical discharge machining power source 140.
By applying a pulse current to the grinding wheel 80 and the graphite electrode 110 through the metal bond fine abrasive grinding wheel 80
Electric discharge molding is performed on the outer peripheral surface of. This molding corresponds to so-called rough molding.

Next, the grinding tool 70 is brought close to the metal bond grindstone 120 of the forming device 100 along the path P3, and the outer peripheral surface of the metal bond fine abrasive grindstone 8o is ground by the metal bond grindstone 120 while supplying grinding fluid from the nozzle 157. do.

At this time, a power supply 150 for electrolytic dressing is connected to the metal bond grinding wheel 12 via a line 151 and a line 154.
By applying current to the electrode 155, the metal bond grindstone 120 is subjected to electrolytic in-process dressing during grinding, and the metal bond grindstone 120 can be dressed efficiently. Therefore, the outer circumferential surface of the metal bond fine abrasive grindstone 80, which is the grindstone to be formed, can be ground to a highly precise mirror surface, and the fine abrasive grains can be made to protrude from the base material to achieve effective dressing.

The state of this grinding process is also shown in FIG. 4, where the metal bond fine abrasive grindstone 80, which is the grindstone to be formed, is ground by the metal bond grindstone 120 with electrolytic in-process dressing to achieve the final forming and dressing. do.

When the outer diameter shape of the metal bonded fine abrasive grindstone 80 which is the grindstone to be formed is a shape other than a cylindrical shape, the graphite electrode 11
0 and the outer diameter shape of the metal bond grindstone 120 may be made into a shape corresponding to the outer diameter shape of the grindstone 80 to be formed.

Next, a case will be described in which the present invention is applied to a machining center type compound machine tool.

FIG. 5 shows an outline of an embodiment of the apparatus, in which a rotary cutting tool 210, a grinding tool 220, etc. are replaceably installed on the headstock 200 side of the multitasking machine tool. Grinding tool 2
20 includes a cup-shaped grinding wheel 224 driven by a rotating spindle 222, and is connected to the electrode 2 via a suitable fixture 226.
28 energizes the grindstone 224 . The grindstone 224 is formed by a metal bonded fine abrasive grindstone.

On the other hand, a graphite mold 11i 250 is attached to the table or bed side 240 of the compound machine tool, and a grinding device 260 for forming is provided. This grinding device 260 includes a spindle 264 driven by a motor 262, and a cup-shaped metal bond grindstone 266 at the tip of the spindle 264.
Attach.

The graphite electrode 250 and the grinding device 260 are provided with a power source 280 for electric discharge machining and a power source 290 for electrolytic forming, respectively, and the positive electrode side of the power source 280 for electric discharge machining is connected to the grindstone 224 side through a line 282. Negative side is line 28
4 to the graphite electrode 250. graphite electrode 25
A nozzle 286 for supplying electrical discharge machining fluid is arranged near the point 0.

The positive side of the power supply 290 for electrolytic dressing is line 29
Electrode 294 in contact with metal bond grindstone 266 via 2
The negative electrode side is connected via a line 296 to an electrode 270 provided close to the metal bond grindstone. Electrode 27
A nozzle 298 for supplying the grinding fluid is arranged near the point 0.

Next, the operation of this device will be explained.

First, attach the rotary cutting tool 210 to the spindle side and cut the upper surface 250a of the graphite electrode 250 along the path P1.6 Next, attach the grinding tool 220 to the spindle,
The lower surface 224 of the metal bond fine abrasive grinding wheel 224 is brought close to the graphite electrode 250 along
A is roughly formed by electrical discharge machining. After the rough forming is completed, the grinding tool 220 is moved along the path P, the grinding bag for forming Y! 1
The lower surface 2 of the metal bond fine abrasive grain grindstone 224 which is the grindstone to be formed by the metal bond grindstone 266 is placed close to the metal bond grindstone 260.
24a is finished and molded to a mirror surface.

During this grinding process, power is applied to the metal bond grinding wheel 266 from the power supply 290 while supplying grinding fluid from the nozzle 298, and by applying electrolytic in-process dressing to the metal bond grinding wheel 266, the grinding efficiency is improved and the formed grinding wheel is The smoothness of the grinding surface 224a of a certain metal bonded fine abrasive grindstone 224 is improved and good dressing is achieved.

In this device, as described above, when forming and dressing a metal bond fine abrasive grindstone.

Rough forming is performed by electrical discharge machining using graphite electrodes, and then final forming and dressing are performed using a metal bond grindstone with electrolytic in-process dressing, making it possible to achieve high-precision forming and dressing in a short time.

[Effects of the Invention] As described above, the present invention provides an electric discharge machining electrode and a metal bonded grindstone on a machine tool to which the grinding tool is attached when forming a metal bonded fine abrasive grindstone attached to the grinding tool. Since a forming device consisting of a grinding means is provided, grindstones can be formed efficiently when necessary. Furthermore, since the electric discharge machining electrode can be machined on-machine using the cutting tool of the same machine tool, the machining accuracy is also improved. Also,
In the forming process, rough forming is first performed by electrical discharge machining, and then finish grinding is performed using a metal bond grinding wheel equipped with an electrolytic in-process dressing means, so the surface of the metal bond fine abrasive grinding wheel that is being formed is finished to a mirror finish. It has the effect of being able to complete a good dressing in a short time.

In addition, graphite electrodes and metal bond grindstones, which are electrodes for electrical discharge machining, are arranged rationally according to the model of the composite machine tool in which the present invention is implemented, and electrical discharge machining equipment and electrolytic in-process dressing equipment are also arranged compactly. Therefore, the effect of having a molding device on the same machine can be maximized.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the principle of the molding method of the present invention, Fig. 2 is an explanatory diagram showing the outline of electrolytic in-process dressing,
FIG. 3 is an explanatory diagram showing an embodiment of the molding apparatus of the present invention, and FIG.
FIG. 5 is an explanatory diagram showing another embodiment of the molding apparatus of the present invention, and FIG. 6 is an explanatory diagram showing a conventional molding method. 20... Metal bond fine abrasive grindstone, 22... Base material, 24... Fine grindstone, 50... Tool rest, 60...
-Cutting tool, 70...Grinding tool. 100... Molding device, 110... Graphite electrode, 12
0...Metal bond grindstone, 140...Power source for electric discharge machining, 150...Power source for electrolytic dressing, 200...Main shaft, 210...Rotary cutting tool, 220...Grinding tool, 250...・Graphite electrode, 260...Grinding device, 280...Power source for electrical discharge machining. 290... Power supply for electrolytic dressing. Figure 1 Applicant Yamazaki Mazatuku Co., Ltd. Agent
Patent Attorney Yoshiaki Numa Kata (2 others) Figure (a) Figure

Claims (2)

[Claims] (1) A method for forming a metal bond fine abrasive grindstone, which includes the steps of: cutting the electric discharge machining electrode using a cutting means equipped with an electric discharge machining electrode and a metal bond grindstone disposed on a machine tool; A process of electrical discharge machining and rough forming of a metal bond fine abrasive grinding wheel using a processed electrical discharge machining electrode, and final forming of the metal bond fine abrasive grinding wheel while applying electrolytic in-process dressing to the metal bond grinding wheel as a grinding means. A method for forming a metal bonded fine abrasive grindstone, comprising: a step of dressing the grindstone with the metal bond; (2) A forming device for performing the forming method according to claim 1 on a multi-purpose machine tool, comprising a cutting tool and a metal bond fine abrasive grindstone that are replaceably disposed on the tool rest or headstock side of the multi-purpose machine tool. A holder, a forming device equipped with a graphite electrode and a metal bond grindstone disposed on the headstock or table side of a multitasking machine tool, and electrical discharge machining that communicates with the metal bond fine abrasive grindstone of a grinding tool and the graphite electrode of the forming device. A power source for electrolytic dressing and a means for supplying an electrical discharge machining fluid, and a power source for electrolytic dressing and a means for supplying a grinding fluid, which communicate with a metal bond grinding wheel of a forming device and an electrode disposed close to the metal bond grinding wheel. Forming equipment for metal bond fine abrasive grinding wheels.