JP3060154B2 - Electroplated grinding wheel for compound grinding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, I Oh <br/> in composite grinding for electricity Chakutogi stone to co-grinding the grinding work and a soft part and the hard part, the grinding wheel portion and a rigid grinding the soft part The present invention relates to a device in which a grinding wheel portion for grinding a portion is integrally formed.

[0002]

2. Description of the Related Art Some undercarriage parts, such as undercarriage parts for automobiles, are required to have high hardness and surface roughness, and the soft part and the hard part of such underbody parts are ground. In performing the processing, a grindstone for grinding the soft portion and a grindstone for grinding the hard portion are manufactured separately, and the soft portion and the hard portion are individually ground using each grindstone.

That is, since the cuttings in the soft part are easily clogged, a grindstone in which abrasive grains having a relatively large particle diameter are electrodeposited in a sparse state is used, while the hard part requires a surface roughness. Therefore, it is necessary to use a grindstone in which abrasive grains having a relatively small particle diameter are electrodeposited in a dense state.

[0004]

When the grindstone for grinding the soft part and the hard part is provided separately as described above, the steps of grinding the soft part and the hard part are separately performed. There is a problem that a grinding device must be used and the number of processing steps increases. According to Japanese Patent Application Laid-Open No. 62-94265, two types of abrasive grains having different particle sizes are partitioned and electrodeposited on an integrated grinding wheel foil, and the abrasive portion having the larger grain size is electrodeposited with the abrasive portion. It is known that grinding is performed simultaneously with a grindstone portion on which abrasive grains having a small diameter are electrodeposited.

[0005] However, when grinding a soft part, the chips in the soft part tend to adhere to the abrasive grains, and when the chips once adhered fall off, a part of the surface of the abrasive grains is peeled off, so-called chipping occurs. Abrasion speed of the abrasive grains is high. On the other hand, when grinding a hard part, the chips in the hard part hardly adhere to the abrasive grains, so that chipping hardly occurs and the wear rate of the abrasive grains is low. Therefore, the wear speeds of the two grinding wheels are different only by simply integrating the grindstone with the large grain size electrodeposited as described in the above-mentioned publication and the grindstone with the small grain size electrodeposited thereon. In addition, the dimensional tolerance of the machined grinding work becomes poor while the life of the individual grinding wheels remains, and the grinding wheels cannot be used any more, resulting in a problem of uneconomic.

In view of the above problems, the present invention reduces the difference between the wear rate of abrasive grains for grinding soft parts and the abrasive rate of abrasive grains for grinding hard parts, and provides a long-life electrodeposition for composite grinding. The purpose is to provide a whetstone.

[0007]

To achieve SUMMARY OF to the above objects, the grinding wheel portion and rigid a composite grinding electrodeposited grindstone for simultaneously grinding the grinding work and a soft substance portion and the hard portion grind the soft part Abrasive grains that are electrodeposited on the grinding wheel portion for grinding the soft portion, in which the grinding wheel portion for grinding the portion is integrally formed.
The grain size of the particles is 100/120 mesh, and the grain size of the abrasive grains electrodeposited on the grindstone portion for grinding the hard portion is 140/170 mesh.
The abrasive grains are ground during a predetermined amount of machining from the start of grinding.
For each whetstone part only the dimension equivalent to the initial wear amount
Increase the outer diameter of the grindstone base material to
Electrodeposits abrasive grains on both whetstones so that they have a large diameter
Then, the predetermined diameter is shaped and removed, and the outer diameter of each grindstone portion is set to a predetermined value.
It is characterized by finishing to the outer diameter .

[0008]

The amount of wear increases as the grain size of the abrasive grains increases, even when grinding a hard part. On the other hand, when the particle size is increased, the surface roughness decreases. Therefore, by increasing the particle size as much as possible within the range where the surface roughness is guaranteed,
Be extended abrasive grains wear rate close to the wear rate of the abrasive grain for grinding soft portion, the life of the grindstone dimensional accuracy of the grinding work increases the working number to deviate from a predetermined tolerance
Wear. Therefore, in the present invention, the electric power is applied to the grindstone for grinding the soft part.
Abrasive particles with a particle size of 100/120 mesh
The particle size of the abrasive particles electrodeposited on the grindstone part for grinding the part is 140 /
170 mesh .

It is known that the wear rate of abrasive grains is highest immediately after the start of grinding, and then decreases as grinding continues. Therefore, after electrodeposition of the abrasive grains, the tip of the
A predetermined amount corresponding to the initial wear amount is removed by shaping, and the wear rate after the start of the grinding process is suppressed by making it slightly worn artificially. The difference in wear rate was reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral W denotes a grinding work, which is a component of a constant velocity joint for transmitting a driving force of an engine to wheels of an automobile. The forged work W is gradually cooled after being forged and adjusted to a hardness of about 25 to 46 HRC. For example, a spline or the like such as a range WH is required to provide a spline or the like to partially require high-frequency mechanical strength. Heat and quench to an HRC of about 58-63. W1 is a portion where the end of the inner race of the bearing (not shown) fitted to the grinding work W is abutted, and is processed after induction hardening so that the surface roughness becomes 6.3S. W2 is a portion where the tip of an annular dustproof seal attached to the outer race side of the bearing slides, and is processed after induction hardening so that the surface roughness becomes 12.5S. Further, W3 is a portion where the gear for wheel speed detection is press-fitted and fixed, so that quenching is not required, and a surface roughness of about 25S is sufficient. Thus, the hard portion grindstone portion 2 for grinding the hard portions W1 and W2 and the soft portion grindstone portion 3 for grinding the soft portion W3 are integrally formed and cut in the L direction. It is necessary to determine the grain size of the abrasive grains to be electrodeposited on each of the grindstone portions 2 and 3 of the composite grindstone 1 to be plunge-processed.

Conventionally, in order to increase the surface roughness of the portions W1 and W2, a mesh for classifying the abrasive grains is ground by using a grindstone with electrodeposited abrasive grains having a relatively small grain size of 200/230. ing. On the other hand, W3 is 10 to prevent clogging.
Grinding is performed using a grindstone on which coarse abrasive grains having a relatively large grain size of 0/120 are electrodeposited. FIG. 2 shows how the wear amount of the abrasive grains differs depending on the size of the abrasive grains.
This will be described with reference to FIG. FIG. 2 shows the amount of wear on the vertical axis and the number of processed grinding works W on the horizontal axis, and a is 100/12.
0 indicates the wear amount of abrasive grains, b indicates the wear amount of 140/170 abrasive grains, and c indicates the wear amount of 200/230 abrasive grains. As shown in the figure, the wear amount increases as the grain size of the abrasive grains increases. That is, it can be seen that the larger the grain size of the abrasive grains, the faster the wear rate of the abrasive grains. By the way, both whetstones 2
The problem when forming 3 integrally is that both grinding stones 2
3 shows the difference in the wear rate of the electrodeposited abrasive grains. If the difference in wear rate between the abrasive grains electrodeposited on both grinding wheel portions 2 and 3 is small, only adjusting the cutting amount of the composite grinding wheel 1 itself, W1.W2 and W3
This is because both dimensions can be kept within the tolerance range, but if one of them wears fast due to a large difference in wear speed, it cannot be adjusted by the cutting depth of the composite grindstone 1. Therefore, as shown in FIG.
120 abrasive grains are electrodeposited, and 2
When the abrasive grains of 00/230 were electrodeposited, as shown by X in FIG. 3, in the combination of the abrasive grains shown by a and the abrasive grains shown by c, the wear rate of the abrasive grains of both whetstone parts 2.3 Since the difference is greatly different, it is impossible to satisfy both the dimensional accuracy of the W1 and W2 portions and the dimensional accuracy of the W3 portion even if both the grinding stone portions 2 and 3 are still in a state where they can be used sufficiently. The grindstone 1 itself can no longer be used. In this case, it is conceivable to change the grindstone to be electrodeposited on the soft portion grindstone 3 from 100/120 indicated by a to 140/170 indicated by b to reduce the particle size. Cause jams. Therefore, in the present invention, the abrasive grains to be electrodeposited on the grindstone portion 2 for the hard portion are changed from 200/230 indicated by c to 140/17 indicated by b.
0 to increase the grain size of the abrasive grains.
As shown in (2), in the combination of the abrasive grains shown in a and the abrasive grains shown in b, the difference in the wear rate between the abrasive grains electrodeposited on the two grindstone portions 2 and 3 was reduced. When the grain size of the abrasive grains is increased as described above, the surface roughness of the W1 portion and the W2 portion slightly decreases within a range where the surface roughness is guaranteed.

By the way, the surface roughness decreases during the sharpening of the abrasive grains immediately after the start of grinding. During this period, the wear rate of the abrasive grains is high and the difference in the wear rate due to the size of the particle size is large. For this reason, as shown in FIG. 2, since the initial wear amount is large for the soft portion grindstone 3 on which the abrasive grains of 100/120 shown in a are electrodeposited as shown in FIG. The amount of shaping (truing) shown in Ta is performed, while the initial wear amount is not large for the hard portion grindstone portion 2 electrodeposited with 140/170 abrasive grains shown in b. The amount of wear indicated by Tb corresponding to the amount of wear of the workpiece is synchronized, and the changes in the amount of wear after the start of machining are synchronized so that a and b are substantially equal to each other. The speed difference was further reduced. By shaping the amount of the abrasive particles electrodeposited on the hard portion grinding wheel portion 2 by the amount indicated by Tb, the sharpness of the abrasive particles is removed, and the surface roughness required for the W1 portion and the W2 portion can be satisfied.

[0013]

As apparent from the foregoing description, according to the present invention, the difference between the abrasive wear rate of grinding the wear rate and the rigid portion of the abrasive grain for grinding soft quality unit's lead, composite grindstone Life can be extended.

Further, a predetermined dimension corresponding to the initial wear is set in advance.
The difference in wear rate can be further reduced by shaping and removing .

[Brief description of the drawings]

FIG. 1 is a view showing a state of grinding with an electrodeposited grinding wheel for composite grinding according to the present invention.

FIG. 2 is a view showing a difference in a change in a wear amount depending on a grain size of abrasive grains.

FIG. 3 is a view showing a difference in abrasion speed difference of abrasive grains between respective particle diameters.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite whetstone 2 Whetstone part for hard parts 3 Whetstone part for soft parts W Grinding work WH Induction hardening range a Transition curve of the amount of wear of abrasive grains of mesh 100/120 b Transition curve of the amount of wear of abrasive grains of mesh 140/170 c Transition curve of wear amount of abrasive grains of mesh 200/230 X Transition curve of wear rate difference between a and c Ya Transition curve of wear rate difference between a and b

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-33270 (JP, A) JP-A-62-94265 (JP, A) JP-A-3-294182 (JP, A) 47173 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B24D 5/14 B24D 3/06

Claims (1)

(57) [Claims] Claims: 1. An electrodeposition grinding wheel for compound grinding for simultaneously grinding a grinding work having a soft part and a hard part, wherein a grinding part for grinding a soft part and a grinding part for grinding a hard part are integrally formed. The grinding wheel for grinding the soft part
The abrasive grains having a grain size that is electrodeposited abrasive grains having a grain size that is wear grinding wheel portion for grinding the hard portion and 100/120 mesh 140 /
Performing a predetermined amount of processing from the start of grinding with 170 mesh
Each abrasive has a size corresponding to the initial amount of
For the stone part, increase the outside diameter of the grindstone base material and
Both whetstone parts so that the diameter becomes large by the specified dimension corresponding to the amount of wear
The abrasive grains are electrodeposited, the predetermined dimensions are removed by shaping, and
An electrodeposited grinding wheel for compound grinding, wherein the outer diameter is finished to a predetermined outer diameter .