JPS616248A - Rotor provided with hub and its manufacture - Google Patents

Abstract

PURPOSE:To prevent the formation of a layer deteriorated in quality at the boundary hub and rotor parts when an integrated rotor provided with a hub is composed of a hub part having a spheroidal or vermicular graphite structure and a rotor part having a flake graphite structure, by regulating the S content of the flake graphite structure to a specified amount or below. CONSTITUTION:Molten metal having the composition of flake graphite case iron contg. <=0.015wt% S is charged into a space 2 for a rotor in a sand casting mold 1 from a sprue 4. At the time when the temp. of the molten metal is 800- 1,140 deg.C, molten metal having the composition of spheroidal or vermicular graphite cast iron is charged into a space 3 for a hub from a sprue 5. Thus, an integrated rotor provided with a hub is manufactured. The rotor is composed of a hub part having a spheroidal or vermicular graphite structure and a rotor part having a flake graphite structure.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composite integrated rotor with a hub and a method for manufacturing the same, and particularly relates to a hub portion having a spherical graphite structure and a rotor portion having a flaky graphite structure. This invention relates to a rotor with a hub and its manufacturing method.

[Conventional technology]

Sliding members used as automobile brake parts,
The so-called hub-equipped rotor has a hub part made of spheroidal graphite cast iron and/or vermicular graphite cast iron, and a rotor part made of flaky graphite structure, and the two are fixed concentrically with mounting bolts and used in an assembled manner.

In other words, the hub part has strong toughness, that is, tensile strength of 30 kgf/am2 or more, elongation of 6% or more, and 2 kgf-1117.
Shock value of 01112 or more 8! Spheroidal graphite cast iron, which has excellent mechanical properties, or vermicelli graphite cast iron, which has properties similar to this, is often used.

On the other hand, the thermal conductivity of the rotor section is 0.12 cal/at room temperature.
cm, see, °C or higher, has good heat crack resistance and wear resistance, prevents noise during braking, has good compatibility with brake pads, and has high damping capacity (comparable liability). FCIO to FC25 flake graphite cast iron with a graphite area of 10% or more is widely used as a material that can meet these properties.

If such a hub and rotor are mechanically coupled, the increase in the number of parts will increase the weight by 10 to 30%, the price will rise, and the occupied volume will increase. We have developed the invention of Application No. 58-130927, that is, a method for manufacturing a sliding member in which the hub part is made of spheroidal graphite cast iron and/or vermicelli graphite cast iron and the rotor part is made of flaky graphite cast iron.

[Problem that the invention seeks to solve]

When the hub part and rotor part, which have different compositions, are metallurgically fused and integrated during casting, the S content of flake graphite cast iron is 0.015.
%, an abnormal layer containing a large amount of eutectic graphite as shown in FIG. 5 is generated at the boundary.

This abnormal layer has extremely poor mechanical properties, for example, the tensile strength is 16 kgf/rsta2 elongation is only 0.8%,
In particular, the impact value is low at 0.1 kgf1/cm2, and it is highly dangerous as an important safety part for automobiles.

An object of the present invention is to provide a hub-equipped rotor and a method for manufacturing the same, in which no material deterioration layer is generated at the boundary between the hub portion and the rotor portion without going through complicated steps.

[Means for solving problems]

The present invention will be explained in detail below based on the drawings.

FIG. 1 is a sectional view of a mold for manufacturing the hub-equipped rotor of the present invention.

The present invention provides a rotor with a hub in which the hub part is made of spheroidal graphite cast iron and/or vermicular graphite structure, and the rotor part is made of flaky graphite structure, and the S content of the flaky structure part is 0.015% by weight (hereinafter simply referred to as 0.015% by weight). In order to manufacture this, a molten metal having a composition of flaky graphite cast iron with an S content of 0.015% or less is placed in the rotor cavity 2 of the sand mold 1. Pour the desired amount of molten metal, and the temperature of this molten metal is 800 to 1,1
At a temperature of 40°C, the molten metal having a composition of spheroidal graphite cast iron or vermicelli graphite cast iron is poured into the hub cavity 3 of the sand mold 1.
It is used to pour hot water into the water.

[For production]

The following operation will be explained using the above configuration.

First, a desired amount of molten metal having a composition of flaky graphite cast iron with the S content regulated to 0.015% or less is injected into the rotor cavity 2 through the sprue 4.

Next, when the temperature of the flaky graphite cast iron injected into the rotor cavity 2 is 800 to 1,140°C, molten metal having a composition of spheroidal graphite cast iron or vermicular graphite cast iron is injected from the sprue 5 into the hub cavity 3. As mentioned above, the temperature and external pressure of the flaky graphite cast iron molten metal is 800 to 1.1.
Since the temperature is 40°C, it is possible to completely fuse with the molten spheroidal graphite cast iron injected later to obtain a good boundary.

When the previously injected molten metal solidifies and the temperature drops below a o'c, the formation of an oxide film on the surface progresses steadily, and it is inevitable that a good metallurgical bonding layer will be obtained.

Also, the temperature is 1. ．． If the temperature exceeds 140°C, a large amount of the previously injected flaky graphite cast iron will be remelted by the spheroidal graphite cast iron, and this will not only prevent a sound bonding layer from being obtained, but also make it difficult to maintain the boundary at the desired position. can't get it.

The reason why the mold is limited to a sand mold is that if the mold is a sand mold, the molten metal poured into the mold will not be rapidly cooled, making it possible to obtain flake graphite cast iron, which is the most preferable ordinary cast iron with excellent braking performance. It's for a reason.

[Example] 1. Chemical composition (1) The chemical composition of the molten metal having the composition of flake graphite steel was
Shown in the table.

(2) The chemical composition of the molten metal having the composition of spheroidal graphite cast iron is
Shown in the table.

2. Mold A CO2 mold was used.

3. Hardness (1) Hardness of flaky graphite structure (HB) 114.119
(2) Hardness of spheroidal graphite structure (HB) 243.25
24.Results As is clear from Figure 2, the hub part has a spheroidal graphite structure with good mechanical properties, and the rotor part has a flake graphite structure with excellent braking performance, as shown in Figure 3. As shown in FIG. 4, the boundary area has normal mechanical properties with no abnormal structures such as eutectic graphite observed.

〔Effect of the invention〕

Since the S content of the molten metal having the scaly graphite cast iron composition is regulated to a low level, no material deterioration layer is formed at the boundary between the hub portion and the rotor portion. This is an extremely important feature of the present invention.

Furthermore, since a sand mold was used, the molten metal was not rapidly cooled, and the rotor part was able to obtain a flaky graphite structure, which is the most preferable for ordinary cast iron.

Further, in FIG. 1, when the molten metal having a flaky graphite composition injected into the rotor cavity 2 is in a semi-solidified state at 800 to 1.140°C, the molten metal having a spheroidal graphite composition is injected into the hub cavity 3. Therefore, there is no fear that the two molten metals will mix together, and moreover, they will not form an obvious boundary surface and will be completely welded and fused.

FIG. 4 shows the structure of the boundary part of a hub-equipped rotor in which the hub part has a permiquierla graphite structure and the rotor part has a flake graphite structure, and no material deterioration layer such as eutectic graphite is observed.

As is clear from the above description, the hub-equipped rotor obtained by the manufacturing method of the present invention has a spheroidal graphite structure and/or a vermicular graphite structure in the hub portion, and a normal flaky graphite structure in the rotor portion and its vicinity. Furthermore, there is no material deterioration such as eutectic graphite at the boundary,
It has extremely excellent characteristics as a rotor with a hub for playing.

In other words, the rotor part having a flaky graphite structure has good thermal conductivity and wear resistance, and has a large damping capacity (not only can it satisfy all the characteristics required for a brake material, but also has good thermal conductivity and abrasion resistance). is spheroidal graphite structure part c//or Vermicu 2
Since it has a graphite structure, its mechanical properties are very good.

Therefore, compared to conventional brake materials, it has extremely superior industrial effects such as weight reduction due to reduced wall thickness, increased service life, improved quality, improved safety, and reduced manufacturing costs. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of a hook shape for manufacturing a rotor with a hub according to the present invention, and FIGS. 2.3 and 4.5 are both microscopic photographs of the metal structure. 1: Sand mold, 2: Rotor cavity, 3: Hub cavity, 4, 5: Gate agent Patent attorney Takayoshi Honma ATzu phase rr 1 in 7 r4' 7 Q xto. 1xto Shiloh J.

Claims (2)

[Claims] (1) In a composite integrated rotor with a hub in which the hub part has a spheroidal graphite structure and/or a vermicular graphite structure and the rotor part has a flaky graphite structure, the S content of the flaky graphite structure part is set to 0.015. A rotor with a hub that is regulated to less than % by weight. (2) When manufacturing a composite integrated rotor with a hub in which the hub part has a spheroidal graphite structure and/or vermicular graphite structure and the rotor part has a flaky graphite structure, the S content is set to 0.
A desired amount of molten metal having a flake graphite cast iron composition regulated to 0.015% by weight or less is poured into the rotor cavity of a sand mold, and when the temperature of the molten metal is 800 to 1,140°C, spheroidal graphite cast iron or vermicular graphite is poured. A method for manufacturing a rotor with a hub, characterized by pouring molten metal having a cast iron composition into the hub cavity of the mold.