JPS60104652A - Dresser for shaping grindstone - Google Patents

Abstract

PURPOSE:To shape and correct a grindstone with a high degree of accuracy, by providing such an arrangement that diamonds are held by means of a diamond binding layer on the surface of a dresser base member made of metals of ceramics having a specific thermal expansion coefficient in order to prevent the relative movement between the grindstone and the dresser. CONSTITUTION:A grindstone shaping dresser 21 is arranged such that diamond particles 25 are dispersed and held on a diamond binding layer 24 formed on the surface of a dresser member 23. The dresser base member 23 of this dresser 21 is made of materials having a low thermal expansion coefficient which is preferably below 5X10<-6>/ deg.C in view of the grindstone having a low thermal- expansion coefficient, so that the axial relative movement between the grindstone and the dresser 21 is made less to enable the grindstone to be shaped with a high degree of accuracy. In addition, there may be used silicon nitride as ceramics for mechanical structure, which is excellent in strength and toughness so that it is suitable for the material of the dresser base member 23.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a dresser for shaping a grindstone.

For example, as shown in FIG. 1, there is a workpiece 3 in the shape of a cylindrical body 1 with grooves 2.2 on the outer 5 surfaces, and as shown in FIG. When shaping the second object 6 into a shape with grooves 5.degree. 5, processing means such as plastic working and cutting are used. Among these, even if 81/A is performed by cutting, processing using a cutting tool, processing using a milling cutter, processing using a broach, processing using a grindstone, etc.
There are various processing methods such as /) processing.

The present invention relates to an improvement of a dresser used for appropriately shaping and repairing the grindstone in the processing using the grindstone. That is, when processing the workpiece 3.6 having the shape shown in Figs. 1 and 2 by grinding with a whetstone (±, as shown in Fig. 314, the grooves 3.6 have a shape and a pitch corresponding to the grooves 2 and 5 on the outer periphery. A grindstone 2 having protrusions 8, 8 may be used.

Therefore, when shaping the whetstone 2 having such a shape from a cylindrical material, or when the whetstone 9 is distorted due to its shape due to use,
When repairing the protrusion 8, as shown in FIG.
, 8 is used. A rotary dresser 11 having a groove portion of 10° 10 Φ diameter corresponding to 8 is used.

This rotary dresser 11 has a structure in which a diamond holding layer 13 is provided on the surface of the dresser body 12, and granular diamonds 14 are held in the diamond holding layer 13, as shown in the lower half of FIG. The cross-sectional shape is equal to the desired finished cross-sectional shape of the workpiece (3, 6). That is, the shape of this dresser 11 is reversed and transferred to the grindstone 2 during grindstone shaping, and is reversed again and transferred to the workpieces (3, 6) during grinding by the grindstone 2.

This grinding process using the grindstone 2 is extremely effective as a method of giving the same shape to a large number of workpieces, but for this purpose, as shown in FIG. It is a prerequisite and important that the relative position in the direction does not change.

By the way, the grinding wheel 2 that has been conventionally used is one in which abrasive grains that act as a 9J blade and grind the workpiece are bonded together, and the abrasive grains include diamond, corundum,
Alumina, zirconia, boron carbide, boron nitride, etc. are used, and as bonds, resinoids using thermosetting synthetic resins such as phenolic resins, silicates, rubber, etc. are used. It has low thermal expansion. On the other hand, the base 1 of the rotary dresser 11
As for the grindstone 2, a material having a larger thermal expansion than the grindstone 2, such as stainless steel, is used.

However, when shaping or repairing the whetstone 2 using the whetstone 2 and rotary dresser 11 described above,
For example, if the rotary dresser 11 is connected to an arrow A shown in FIG.
Relative movement may occur in the direction of . Here, if the rotary dresser 11 moves relative to the direction of arrow A by Δ, then for example, the dotted line m
Shaping and repair will be done in the shape shown. Therefore, the width of the protrusion 8 is reduced by the amount of Δ, and a step 15 is formed at the base of the protrusion 8. In addition, when relative movement occurs in the direction of arrow A while the rotary dresser 11 is gradually cutting toward the root of the protrusion 8, the right side of the protrusion 8 will move as shown in an exaggerated manner in FIG. Steps, slopes, etc. are formed.

Therefore, it is important to prevent relative movement in the +11+ direction between the grindstone 2 and the rotary dresser 11 in order to improve the degree of shaping and repair of the grindstone 2.

The main cause of such relative movement in the axial direction is heat generated during shaping and repair. That is, the heat added to the grinding wheel 2 and the rotary dresser 11 when shaping or repairing the grinding wheel 2 includes the heat generated by each part of the machine during operation, the heat generated at the point of contact between the grinding wheel 2 and the workpiece, and the heat generated by the grinding wheel 2 and the rotary dresser 11. There is heat generated at the point of contact with the dresser 11, and the causes and locations of this heat generation are various. Therefore, each temperature and the thermal expansion based on this temperature rise also differ depending on the location, so the grinding wheel shaft This occurs due to relative movement between the shaft and the rotary dresser shaft.

In the past, some machines have been developed that take measures to minimize the relative movement between the grinding wheel spindle and the rotary dresser spindle, but even so, Fig. 5 and fJ
In some cases, defective shaping or defective repair as illustrated in FIG. 56 may occur. In particular, when the workpiece is long in the axial direction, the grinding wheel 2 and the rotary dresser 11 may also be long. Although it is made from a material that does not expand thermally, the rotary dresser 1
Since grinding wheel 1 is made of a material that generates more thermal expansion than the grinding wheel 2, this thermal expansion may cause relative movement between the grinding wheel shaft and the rotary dresser shaft, as shown in FIG. This causes the generation of Δ statements.

For example, if the left end 11a of the rotary dresser arc 11 shown in Figure 5 can be positioned and accessed to the machine shaft, when the temperature rises, the right end 1
1b moves to the right. Here, the base body 12 of the rotary dresser 11 is made of stainless steel, and its heat 1
When the change tension coefficient is about 15Xl0-6/'C,
For example, when the distance fa, L between the reference left end 11a and the groove (10a) near the right end 11b is 20011III+te, the movement amount Δ of the groove 10a is 3 m per A1°C in terms of temperature, and the temperature rise At 20°C, it reaches 60 ILm. Therefore, during precision grinding, the thermal expansion of the rotary dresser 11 is difficult to monitor and ignore. Therefore, in the conventional case, in order to perform high-precision shaping or repair of the grindstone 2, especially when it is long in the axial direction, there is a problem in that it is necessary to divide the rotary dresser 11 into a plurality of parts and drive each part to rotate. It had

This invention was made by focusing on the conventional problems as described above, and when a grindstone shaping dresser is used to shape or repair a grindstone, the relative movement between the grindstone shaping dresser and the grindstone is difficult. As a result, the grindstone can be shaped with high accuracy using a grindstone shaping dresser (including shaping the initial shape of the grindstone and repair shaping after shaping), especially when shaping a grindstone used to process long workpieces. Another object of the present invention is to provide a dresser for abrasive head shaping that eliminates the need for dividing the shaping process into multiple dressers.

That is, the grinding wheel shaping drainer according to the present invention is
In one embodiment, the dresser base has a structure in which a diamond retention layer is provided on the surface of the dresser base, and the diamond is retained in the diamond retention layer, and the dresser base is made of a low thermal expansion material. The dresser base of No. 111 is made of gold with a thermal expansion coefficient of less than 5 x 10-6/'O and/or a ceramic material (thermen), and the dresser base is provided with a cooling medium. The present invention is characterized in that a flow path is provided.

Next, embodiments of the present invention will be described in detail based on the drawings.

FIGS. 7 and 8 are a front view and a partial vertical cross-sectional view, respectively, of a dresser for grindstone shaping according to an embodiment of the present invention. 11η of a shape corresponding to the shape of the workpiece
It has portions 22, 22... As shown in FIG. 8, this grindstone shaping dresser 21 has a structure in which a diamond holding layer 24 is provided on the surface of a dresser base 23, and granular diamonds 25 are dispersed and held in the diamond holding layer 24. .

In the grindstone shaping dresser 21 according to the present invention, the dresser base 23 is made of a low thermal expansion material. As this low thermal expansion material, as mentioned above, the grinding wheel 2
is more preferably 5 x 10 because of its low thermal expansion.
It has been confirmed through various experiments that by using a grindstone of -6/℃ or below, the relative movement in the axial direction between the grindstone 2 and the dresser 21 can be reduced, and highly accurate grindstone shaping is possible. . Specifically, as the material for the dresser base 23, it is possible to use, for example, Impal, which is a Ni-Nkel-iron alloy and has a small coefficient of thermal expansion of 2×10-67”O or less. There is also a super impal alloy with a coefficient of thermal expansion that is lower than that of O, but it is usually not necessary to use a material with a coefficient of thermal expansion as low as this. The coefficient of thermal expansion is 5.
Copal of about X10-'/'O can also be used. Other metal materials such as tungsten and molybdenum meet the requirements for low thermal expansion materials, but they have the drawbacks of being expensive and difficult to process.

On the other hand, as a non-metallic material, stone fu glass has a fairly small coefficient of thermal expansion, about 0.4 Since the mechanical properties such as strength are not good,
Although it may be used as a composite material, it is difficult to use as a single material.

In addition, there is silicon nitride as a ceramic for mechanical structures, and this silicon nitride has excellent strength and toughness.
Since the coefficient of thermal expansion is approximately 3.2 to 3.5×10 −′/′O, it is suitable as a material for the dresser base 23 described above.

There are several types of silicon nitride i-ceramics depending on the manufacturing method, additives, etc. Generally, types with excellent mechanical properties are difficult to process, so it is best to select them appropriately. It is also a good idea to choose a material that has slightly inferior mechanical properties but can be relatively easily machined with a diamond tool or the like.

In this case, the dresser base 23 is less subject to tensile stress, which is a weak point of ceramic materials, so it is possible to use a low-grade product that is relatively easy to process even if its mechanical properties are slightly inferior. . Furthermore, it is a composite material of metal and ceramics with a coefficient of thermal expansion of 5XlO-
It is also possible to use cermet materials as small as 6/'O or less.

In this way, for the dresser base 23, instead of the conventional steel having a thermal expansion coefficient of approximately 11 to 15 x 10-6/'C, materials such as Imphal, Kovar, and silicon nitride ceramics having a thermal expansion coefficient of 5XIO-6/'C can be used. Metal and/or ceramic materials with a temperature of 6/°C or less are used, and as a result, there is little thermal deformation, and even with a dresser that is long in the axial direction, high-precision grindstone shaping can be performed stably over a long period of time. Note that the material for the body 23 is not limited to the above-mentioned Imphal, Konohale, and silicon nitride ceramics; It has excellent properties and good workability, and the dresser base 2
Any material that satisfies the necessary conditions can be used as the material in step 3.

In another embodiment of the present invention, the dresser base 23 is provided with a structure as shown in FIG. 9 to prevent the dresser 21 from being heated by the heat generated at the contact point between the grindstone 2 and the dresser 21 during grindstone shaping. It is also desirable to provide a cooling medium flow path 26 for a cooling medium such as air or water, if necessary.

Furthermore, an eighth mark on the surface of the dresser base body 23 is
A diamond retaining layer 24 is provided as shown in FIG. 9 and FIG. This diamond holding layer 24 is provided on the surface of the dresser base 23 in the form of a metal sintered body or a metal deposit by powder metallurgy, electroforming, or the like.

In this case, the dresser base 23 and the diamond retention layer 2
4 each have a unique coefficient of thermal expansion, but since the dresser base 23 and the diamond retention layer 24 are strongly bonded and the diamond retention layer 24 is thin, the diamond retention layer 24 has a unique coefficient of thermal expansion. The dresser base 23 expands and contracts to follow the dresser base 23, which is larger in size than the dresser base 23. Therefore, the shaping error 6 shown in FIG.

Then, this diamond holding layer 24 holds granular diamonds 25 to form a dresser for grindstone shaping.

Therefore, the grindstone shaping dresser 2 shown in the above embodiment
If you use the grindstone 1 to shape and repair the grindstone, even if the grindstone 2 and the dresser 21 are heated,
Since the grinding wheel 2 originally has low thermal expansion and the dresser 21 also has low thermal expansion, there is no mutual movement between the grinding wheel 2 and the dresser 21, so that highly accurate shaping and repair of the grinding wheel 2 is possible. .

In addition, during this shaping and repair, the dresser 21 can be cleaned by flowing a cooling medium such as cooling liquid or cooling gas into the cooling medium flow passage 26 provided in the dresser base 23.
Since it becomes possible to more effectively suppress the thermal expansion of the grindstone 2, it becomes possible to shape and repair the grindstone 2 with higher precision.

As explained above, according to the present invention, in the dresser for grindstone shaping, in which a diamond holding layer is provided on the surface of the dresser base, and the diamond is held in the diamond holding layer, the dresser base is made of a low thermal expansion material. Therefore, when the grindstone shaping dresser according to the present invention is used to shape or repair the grindstone, relative movement is unlikely to occur between the grindstone shaping dresser and the grindstone. The 5F function is used to perform shaping and repair with high precision, and is particularly useful for processing workpieces that are long and have a large number of grooves or protrusions, or have long pitches of grooves or protrusions at the same time. When shaping or repairing a long whetstone, you can shape or repair the whetstone with high precision by using a dresser for whetstone shaping that is also long, without dividing the dresser for shaping the whetstone in the axial direction as in the past. It can be repaired, and the drive source for the grindstone shaping dresser can be made from a single drive source, which simplifies the structure considerably, and at the same time solves the problem of mutual positioning accuracy when the grindstone shaping dresser is divided into parts. , it has very excellent effects such as being able to significantly reduce processing costs.

[Brief explanation of the drawing]

1 and 2 are perspective views showing examples of the shape of a workpiece having grooves, FIG. 883 is a perspective view showing an example of the shape of a grindstone used to grind the workpiece, and FIG. 4 is a perspective view of the grindstone. 5 is a longitudinal sectional view partially showing the positional relationship between the grindstone and the dresser for grindstone shaping, and FIG. 6 is a front view showing an example of the dresser for grindstone shaping used for shaping and repair of・A partial cross-sectional explanatory diagram showing an example of the shape of a protrusion of a grindstone that is ground when the grinder generates relative movement. FIGS. 7 and 8 are front views of a dresser for grindstone shaping according to an embodiment of the present invention. FIG. 9 is a partial longitudinal sectional view of a dresser for grindstone shaping according to another embodiment of the present invention. 21... Dresser for grindstone shaping. 22...Groove portion, 23...Dresser base, 24...Diamond holding layer, 25...Diamond, 26...Cooling medium flow path. Patent Applicant Ll 1$ Jidosha Co., Ltd. Patent Applicant Asahi Diamond Industries Co., Ltd. Representative Patent Attorney Oshio 'J 1st @ 12th Floor 34th Figure 1 ((10a) 5th Figure 6th 8Figure 5 s, 22 n5 do2

Claims (3)

[Claims] (1) A dresser for grindstone shaping, in which a diamond holding layer is provided on the surface of a dresser base, and the diamond is held in the diamond holding layer, the dresser base being made of a low-temperature I11 tension material. dresser. (2) The dresser base has a thermal expansion coefficient of 5 x 10-6/
'C! A dresser for grindstone shaping according to claim (1), which is made of the following metal and/or ceramic materials. (3) The dresser for grindstone shaping according to claim (1) or (2), wherein the dresser base is provided with a flow path for a cooling medium.