WO2014108930A1

WO2014108930A1 - Brake caliper manufacturing method

Info

Publication number: WO2014108930A1
Application number: PCT/JP2013/000017
Authority: WO
Inventors: 佐藤　慎也; 猪狩　隆彰; 邦男片岡; 杉田　薫
Original assignee: 日本軽金属株式会社
Priority date: 2013-01-08
Filing date: 2013-01-08
Publication date: 2014-07-17
Also published as: JPWO2014108930A1; JP5382264B1

Abstract

[Problem] To provide a brake caliper manufacturing method designed to limit the occurrence of large gas bubbles [porosity] and shrinkage cavities (shrinkage holes) [shrinkage cavity] in the thick-walled sections, improve processing precision and improve strength. [Solution] A method for manufacturing brake calipers equipped with: opposing sections (12, 13) that oppose each other with a hollow section (11) for accommodating the disc therebetween; connecting sections (14) for connecting both sides of the opposing sections (12, 13); and a first cylinder section (15) that is formed in one of the two opposing sections (12, 13) and is for forming a cylinder. In said method, after exchanging the interior of the mold cavity (20) with oxygen, the injection of molten aluminum from molten metal gates (18) provided on the opposing section (13) side, which has a second cylinder (16), is performed aiming in the direction of the first cylinder section-side wall surfaces of the thick-walled sections on both sides of the first cylinder section (15).

Description

Brake caliper manufacturing method

The present invention relates to a method for manufacturing a brake caliper, and more particularly to a method for manufacturing an aluminum brake caliper using a die casting method.

Conventionally, there are various methods for casting aluminum products. For example, there are a gravitational die casting method and a low pressure casting method in which a molten metal is pushed up in a direction opposite to gravity and poured into the die (for example, Patent Document 1). reference).

Further, as a technique capable of improving the dimensional accuracy and improving the productivity as compared with the above casting method, there is known a die casting method in which a molten metal is poured (injected / filled) into a mold and cast at a high speed and high pressure. Yes. A die casting method is also used as a method for producing an aluminum product (see, for example, Patent Document 2).

Also, as a die casting method, in order to prevent the formation of nests due to air entrainment in the cavity, the molten metal is poured (injected / filled) after the air in the mold cavity is replaced with an active gas, for example, oxygen gas. A non-porous die casting method {PF (Pore-Free) method} is also known (see, for example, Patent Document 3). According to the non-porous die casting method, oxygen filled in the cavity reacts with the molten aluminum to form a fine oxide film (Al2O3) and is dispersed in the product, so that adverse effects on the product can be suppressed.

Generally, an aluminum disc brake caliper (hereinafter referred to as a brake caliper) is manufactured by, for example, a gravity casting method as disclosed in Patent Document 1. Further, as a document suggesting that a brake caliper is manufactured using a die casting method, for example, there is a document shown in Patent Document 2, but a specific manufacturing method thereof is not mentioned.

The brake caliper has a facing part that faces the storage space (hollow part) that houses the disc, and a connecting part that connects both sides of the facing part, and a piston can be inserted into at least one of the facing parts. The cylinder portion has a complicated shape.

In addition, a disk that rotates at high speed is clamped by a brake pad attached to the piston, and the rotation is stopped. Since final dimensional accuracy requires precision, manufacturing is performed by a die casting method that can be cast with high dimensional accuracy. As a result, the number of man-hours for final finishing can be reduced, so that it is desired to realize a die casting method.

JP 2000-220667 A Japanese Patent Laid-Open No. 5-118360 Japanese Patent Laid-Open No. 2000-52016

However, in brake calipers that require a machining surface such as a cylinder part for forming a cylinder or a disk housing part at the opposite part, the molten metal that is press-fitted and filled into the cavity starts to solidify from the low-temperature part and reaches the inside. The portion that solidifies first due to the shrinkage during solidification solidifies while attracting hot water from the thick portion of the oppositely solidified portion. As a result, a round bubble {Porosity} is generated after solidification by the gas generated in the molten metal in the thick part, and is contracted by a portion that has been first solidified and contracted (shrinking nest) { Shrinkage Cavity} occurs.

As described above, when bubbles {Porosity} and shrinkage nests {Shrinkage Cavity} are generated on the processing surface side of the cylinder forming portion or the disk housing portion, the processing accuracy of the processing surface is lowered. At the same time, there is a concern that the strength of the product will decrease.

The present invention has been made in view of the above circumstances, and suppresses the generation of large bubbles {Porosity} and shrinkage nests {Shrinkage Cavity} in the thick part, improving processing accuracy and strength It is an object of the present invention to provide a method for manufacturing a brake caliper that can improve the speed.

In order to achieve the above object, a method for manufacturing a brake caliper according to the present invention includes a facing portion that is opposed to a hollow portion that accommodates a disc, a connecting portion that connects both sides of the facing portion, and the both facing portions. A brake caliper manufacturing method comprising: a first cylinder portion for forming a cylinder formed on one side; after filling a mold cavity with oxygen at a pressure higher than atmospheric pressure, aluminum from a gate The injection of the molten metal is performed in a direction toward the wall surface on the first cylinder portion side of the thick portion on both sides of the first cylinder portion.

In the present invention, the brake caliper includes one having the first cylinder part for forming the cylinder and the second cylinder part for forming the cylinder on the opposite side of the opposing parts.

In the present invention, the brake caliper further includes a brake caliper provided with a cast portion through which a cooling medium provided in the facing portion where the first cylinder portion is formed circulates.

Further, in the present invention, the injection of the molten aluminum from the molten metal gate may be performed in a direction that rebounds from the cast-out portion toward the wall surface on the first cylinder portion side.

By configuring in this way, the injection of molten aluminum is performed in the direction from the thickened part on both sides of the first cylinder part for cylinder formation toward the first cylinder part side wall surface or from the cast part to the first cylinder. Since it is performed in a direction that rebounds in the direction toward the wall surface on the part side, bubbles contained in the molten aluminum can be dispersed and refined.

Further, in the present invention, it is preferable to inject and inject molten aluminum into the cavity of the mold with a water-soluble release agent diluted with water attached to the mold. In this case, it is preferable to use a silicone oil-based water-soluble release agent or a graphite-based water-soluble release agent as the water-soluble release agent.

By configuring in this way, oxygen in the cavity reacts with the molten aluminum and forms an oxide film (Al2O3) on the surface of the molten aluminum. Therefore, it is difficult for the moisture to react with the molten aluminum. A certain amount of H2O becomes water vapor by the heat of the molten aluminum, and H2O does not react and forms fine bubbles dispersed in the casting.

According to this invention, injection of the molten aluminum is performed in the direction toward the first cylinder portion side wall surface of the thick portion on both sides of the first cylinder portion for forming the cylinder, so that it is included in the molten aluminum. Bubbles can be shattered and refined, so that the generation of bubbles {Porosity} and shrinkage nests {Shrinkage Cavity} is suppressed to improve processing accuracy and strength. Can do.

In addition, with the water-soluble release agent diluted with water (silicon oil-based water-soluble release agent or graphite-based water-soluble release agent) attached to the mold, the molten aluminum is injected into the mold cavity. By press-fitting, a part of the water in the release agent evaporates and remains in the product as fine bubbles, so that the shrinkage nest {Shrinkage Cavity} can be further reduced (miniaturized). it can.

It is a perspective view which shows the brake caliper made from aluminum produced by the manufacturing method of the brake caliper concerning this invention. It is a front view of the said brake caliper. It is a rear view of the said brake caliper. It is a left view of the said brake caliper. It is a right view of the said brake caliper. It is a top view of the said brake caliper. It is a bottom view of the brake caliper. FIG. 6 is a cross-sectional view taken along line AA in FIG. 5. FIG. 8 is a cross-sectional view taken along line BB in FIG. It is a flowchart which shows the process of the manufacturing method of the brake caliper which concerns on this invention. It is a schematic sectional drawing which shows 1st Embodiment of the process of the brake caliper created by the manufacturing method which concerns on this invention. It is a schematic sectional drawing which shows 2nd Embodiment of the process of the brake caliper created by the manufacturing method which concerns on this invention. It is a schematic sectional drawing which shows the die-casting process of the comparative example which injects a molten metal inside. It is a schematic sectional drawing which shows the die-casting process of the Example which inject | emits a molten metal toward the casting part of the opposing part of thickness. It is an enlarged photograph which shows the cross section of the thick part by the side of the cylinder opening part of the brake caliper created by the die-casting process of the said comparative example. It is an enlarged photograph which shows the cross section of the thick part by the side of the 1st cylinder part for cylinders of the brake caliper created by the die-casting process of the said Example.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

First, the brake caliper produced by the die casting process of the manufacturing method according to the present invention will be described with reference to FIGS.

As shown in FIGS. 1 to 9, the brake caliper 10 connects

opposing portions

12 and 13 that face each other across a hollow portion 11 that forms a space for accommodating a disk, and both sides of the

opposing portions

12 and 13. The connecting portion 14, the first cylinder portion 15 for forming a cylinder for slidably fitting a piston formed on one facing portion 12 on the opposite side of both facing

portions

12, 13, and the other facing portion 13 The second cylinder part 16 for forming the cylinder formed in the first part and the cast part 17 through which the cooling medium provided in the facing part 12 in which the first cylinder part 15 is formed circulates. Further, a molten aluminum gate 18 is provided on the side of the facing portion 13 having the second cylinder portion 16.

In the present embodiment, the cylinder forming first cylinder portion 15 and the second cylinder portion 16 provided in the brake caliper 10 are formed in a circular cross section, and the same core ( The gate 18 is formed on the facing portion 13 having the second cylinder portion 16 for forming the cylinder that is not on the side from which the core is removed. In this case, the gates 18 are provided at four positions symmetrical to the center of the brake caliper 10. The first cylinder portion 15 and the second cylinder portion 16 are preferably circular in cross section, but may be a horizontally long oval shape or a square cross section, and are not necessarily circular in cross section. Further, the gates 18 are not necessarily provided at four places, and any number may be provided as long as at least two places on both sides are provided.

The hollow portion 11 extends to a part of the connecting portion 14 from a rectangular hollow base portion 11 a penetrating the center portion of the brake caliper 10 and short sides on both sides of the rectangular hollow base portion 11 a on the front side of the brake caliper 10. And a pair of grooves 11b.

The brake caliper 10 formed as described above has a brake pad in which a disc accommodated in the hollow portion 11 is attached to a pair of cylinders accommodated in the first cylinder portion 15 and the second cylinder portion 16 for forming the cylinder. To stop the rotation of the disc.

Next, the manufacturing method according to the present invention will be described in detail with reference to FIGS. 10, 11A and 11B.

First Embodiment <Step S-1: Mold Assembly / Releasing Agent Application>
While assembling the mold, using a core (not shown), the facing

portions

12 and 13 that face each other with the hollow portion 11 interposed therebetween, and the connecting portion 14 and the facing portion 12 that connect both sides of the facing

portions

12 and 13. A cavity 20 of the cast-out part 17 that bulges on both the left and right sides is formed, and a first cylinder part 15 for forming a cylinder is formed at the center position of one facing part 12, and a second cylinder for forming a cylinder is formed at the other facing part 13. Cylinder portion 16 is formed (see FIG. 11A (a)).

After assembly of the mold, a water-soluble mold release agent diluted with water, for example, 50 to 100 times is applied to the inner surface of the mold. As the water-soluble release agent in this case, for example, a silicone oil-based water-soluble release agent or a graphite-based water-soluble release agent is suitable.

<Step S-2; oxygen filling step>
The cavity 20 is filled with oxygen gas (O2) at a pressure higher than atmospheric pressure, and the air in the cavity 20 is replaced with oxygen gas.

<Step S-3: Die casting process>
The molten aluminum is injected from the gate 18 provided on the facing portion 13 side that forms the second cylinder portion 16, and the molten aluminum flows into the cavity 20. At this time, molten aluminum is injected into the facing portion 13 from the two gates 18 on both inner sides of the gate 18, and the first cylinder portion 15 side for forming the cylinder of the facing portion 12 from the two gates 18 on both outer sides. A molten aluminum is injected toward the wall surface (see FIG. 11A (b)).

Then, the molten aluminum spreads after passing through the gate 18, flows to the left and right connecting portions 14, and flows to the other facing portion 12. At this time, the molten metal flowing through the facing portion 13 flows so as to surround the second cylinder portion 16. Further, the molten aluminum flowing through the other facing portion 12 flows so as to surround the first cylinder portion 15 for forming the cylinder, and also flows so as to surround the left and right cast portions 17.

Thus, by injecting molten aluminum from the two gates 18 on both outer sides toward the wall surface on the first cylinder portion 15 side for forming the cylinder of the facing portion 12, the molten metal is refined in the form of mist or droplets. As a result, the reaction between the oxygen gas and the molten metal is promoted. Therefore, since the molten aluminum press-fitted and filled into the cavity 20 begins to solidify from a low temperature portion and reaches the inside, the portion that solidifies first due to the shrinkage during solidification takes hot water from the opposed portion 12 having a slow solidification. Although it solidifies while attracting, since the bubbles generated in the melt of the thick facing portion 12 are fine, the generation of round bubbles {Porosity} generated after solidification can be suppressed. Shrinkage nest {Shrinkage Cavity} generated by being pulled by the contracted portion can be suppressed.

In addition, with the water-soluble mold release agent diluted with water attached to the mold, the molten aluminum is injected into the cavity 20 of the mold and press-fitted, so that the oxygen in the cavity 20 reacts with the molten aluminum, Since an oxide film (Al2O3) is formed on the surface of the molten aluminum, it is difficult for moisture to react with the molten aluminum. A certain amount of H2O in the release agent becomes water vapor by the heat of the molten aluminum, and H2O does not react. In addition, nitrogen (N) inevitably remaining even after oxygen substitution forms fine bubbles dispersed in the casting to suppress the shrinkage nest {Shrinkage Cavity}. A part of H2O reacts with aluminum to become Al2O3 and H, which becomes H atoms dissolved in solid and does not become bubbles, and does not contribute to the suppression of shrinkage nest {Shrinkage Cavity}. .

Here, the molten metal is a material excellent in pressure resistance, mechanical properties and corrosion resistance among aluminum alloys for die casting, for example, equivalent to ADC3 {Cu: 0.6 mass%, Si: 9.0 to 10.0 mass%, Mg : 0.4 to 0.6 mass%, Zn: 0.5 mass%, Fe: 1.3 mass%, Mn: 0.3 mass%, Ni: 0.5 mass%, Sn: 0.1 mass% , Balance Al}.

<Step S-4: Heat treatment step>
After the die casting process, the semi-finished product manufactured by the die casting process is subjected to heat treatment (for example, T6 treatment). That is, the semi-finished product is subjected to artificial age hardening after solution treatment. In this case, solution treatment is carried out at a temperature of 480 to 520 ° C. for 30 minutes to 5 hours, and after quenching by water cooling, aging is carried out at a temperature of 150 to 180 ° C. for 3 to 15 hours.

<Step S-5: Finishing>
After the heat treatment step, the inner peripheral surface of the first cylinder part 15 for forming the cylinder is finished, and a hydraulic oil communication path communicating with the first cylinder part 15 is formed to produce the brake caliper 10. In this case, the communication path can be formed by using a tool such as a drill, and after the communication path is formed, the hydraulic oil supply port is formed at the insertion port of the drill. Note that unnecessary drill insertion holes are closed with stoppers. In addition, you may perform a finishing process after a die-casting process, without performing heat processing.

Second Embodiment As shown in FIG. 11B, the second embodiment is similar to the first embodiment, assembling the mold (see step S-1, FIG. 11B (a)), oxygen replacement step (step S). -2) and a heat treatment process (step S-4), but differ in the injection form of the molten aluminum in the die casting process.

That is, in the second embodiment, molten aluminum is injected into the facing portion 13 from the two gates 18 on both sides of the gate 18 provided on the facing portion 13 side that forms the second cylinder portion 16, The molten aluminum is injected from the two gates 18 toward the casting part 17 of the facing part 12 so as to bounce in the direction from the casting part 17 toward the wall surface on the first cylinder part 15 side for cylinder formation. (See FIG. 11B (b)).

In the die casting process of the second embodiment, the molten aluminum spreads after passing through the gate 18, spreads to the left and right connecting portions 14, and flows to the other facing portion 12. At this time, the molten metal flowing through the facing portion 13 flows so as to surround the second cylinder portion 16. Further, the molten aluminum flowing through the other facing portion 12 flows so as to surround the first cylinder portion 15 for cylinder formation and also flows so as to surround the left and right cast portions 17.

In this way, molten aluminum is injected from the two gates 18 on both outer sides toward the cast part 17 of the facing part 12, and from the cast part 17 toward the wall surface on the first cylinder part 15 side for cylinder formation. By injecting the molten aluminum in a direction that rebounds in the direction, the molten metal becomes finer in the form of mist or droplets as in the first embodiment, so that the reaction between the oxygen gas and the molten metal is promoted. . In addition, by injecting the aluminum melt into the cast-out part 17 through which the cooling medium circulates and bounces back, the thick opposed part 12 can be filled with the cooled molten aluminum, and the solidification time of the opposed part 12 is shortened. can do. Therefore, since the molten aluminum press-fitted and filled into the cavity 20 begins to solidify from a low temperature portion and reaches the inside, the portion that solidifies first due to the shrinkage during solidification takes hot water from the opposed portion 12 having a slow solidification. Although it solidifies while attracting, since the bubbles generated in the melt of the thick facing portion 12 are fine, the generation of round bubbles {Porosity} generated after solidification can be suppressed. Shrinkage nest {Shrinkage Cavity} generated by being pulled by the contracted portion can be suppressed.

Further, according to the second embodiment, as in the first embodiment, the molten aluminum is injected into the cavity 20 of the mold and press-fitted with the water-soluble release agent diluted with water attached to the mold. Therefore, the same effect as the first embodiment can be obtained. That is, oxygen filled in the cavity 20 due to oxygen substitution reacts with the molten aluminum and forms an oxide film (Al2O3) on the surface of the molten aluminum, so that the moisture does not easily react with the molten aluminum. A certain amount of H2O becomes water vapor due to the heat of the molten aluminum, and H2O does not react and forms fine bubbles dispersed in the casting together with nitrogen (N) inevitably remaining even after oxygen substitution. To suppress the shrinkage nest {Shrinkage Cavity}. A part of H2O reacts with aluminum to become Al2O3 and H, which becomes H atoms dissolved in solid and does not become bubbles, and does not contribute to the suppression of shrinkage nest {Shrinkage Cavity}. .

According to the above-described embodiment configured as described above, the injection of the molten aluminum is directed toward the first cylinder portion 15 side wall surface of the thick portion on both sides of the first cylinder portion 15 for forming the cylinder, or By performing in the direction of rebounding from the cast-out part 17 toward the wall surface on the first cylinder part 15 side, the bubbles contained in the molten aluminum can be dispersed and refined, so that the bubbles {porosity ( Porosity)} and shrinkage nest (shrinkage nest) {ShrinkagerinkCavity} can be suppressed to improve processing accuracy and strength.

The contents according to the present invention are not limited to the above embodiment. For example, the manufacture of a so-called floating caliper that does not have the second cylinder portion is also included. The direction toward the wall surface on the first cylinder portion side of the thick portion on both sides of the first cylinder portion is the direction in which the molten metal injected from the gate directly collides with the wall surface of the first cylinder portion, or The direction in which the molten metal hits or rebounds on the mold or the core near the thick portion side is not included in the direction in which the molten metal rebounds from the portion toward the wall surface on the first cylinder portion side.

In the above embodiment, one of the opposing portions is described as having one cylinder portion, but is not limited to this and includes two or more. Even when there are two or more cylinder parts on one of the opposed parts, the molten metal is injected onto the wall surface near the thick part on both sides of the cylinder part.

Furthermore, the position of the gate may be provided in the facing portion on the same side, not the other side of the facing portion of the first cylinder portion.

Included in the present invention is a die casting method in which the inside of the cavity is vacuumed and depressurized before the oxygen filling step.

In addition, with the water-soluble release agent diluted with water (silicon oil-based water-soluble release agent or graphite-based water-soluble release agent) attached to the mold, the molten aluminum is injected into the mold cavity. By press-fitting, most of the moisture in the release agent evaporates and remains in the product as fine bubbles, so that the shrinkage nest {Shrinkage Cavity} can be further reduced (miniaturized). .

Next, the porosity of the brake caliper produced by the brake caliper manufacturing method according to the present invention, the air bubbles {Porosity} on the first cylinder portion 15 side of the opposing portion 12 and the shrinkage nest (shrinkage) Nest) The results of tests conducted to examine the state of {Shrinkage Cavity} will be described.

A comparative example and an example having the same shape as the brake caliper 10 are manufactured by the following method using an alloy equivalent to ADC3 as the material of the molten aluminum, and the porosity and the first cylinder forming cylinder for the facing portion 12 are prepared. The state of the bubbles {Porosity} and the shrinkage nest (shrinkage) {Shrinkage シリンダ Cavity} on the cylinder part 15 side was examined.

<Porosity>
In the comparative example, as shown in FIG. 12, the brake caliper 10 was produced by injecting molten aluminum from both outer gates 18 inward. When the analysis value of the mass fraction of the component of the produced brake caliper 10 and the specific gravity of the component were measured, the composition specific gravity of the brake caliper 10 of the comparative example was 2.71634.

Further, when the specific gravity of the brake caliper 10 of the comparative example was measured, the specific gravity of the brake caliper 10 of the comparative example was 2.660186.

From the above, the porosity of the brake caliper 10 of the comparative example was 2.0674% from the ratio of the composition specific gravity (2.771634) and the actual specific gravity (2.666018) of the brake caliper 10 of the comparative example.

On the other hand, in the embodiment, as shown in FIG. 13, the injection of molten aluminum from both outer gates 18 rebounds in the direction from the cast portion 17 toward the wall surface on the cylinder forming first cylinder portion 15 side. The brake caliper 10 was produced by going to the front. When the analysis value of the mass fraction of the component of the produced brake caliper 10 and the specific gravity of the component were measured, the composition specific gravity of the brake caliper 10 of the example was 2.71273.

Further, when the actual specific gravity of the brake caliper 10 of the example was measured, the actual specific gravity of the brake caliper 10 of the example was 2.662504.

From the above, the porosity of the brake caliper 10 of the example was 1.8515% from the ratio of the composition specific gravity (2.771273) and the actual specific gravity (2.652504) of the brake caliper 10 of the example.

From the above test results, it was found that the porosity of the comparative example was 2.0674%, whereas the porosity of the example was 1.8515%, which was about 0.2% less than the comparative example. . Since the comparison of the porosity is a comparison of the porosity of the entire brake caliper, it is estimated that there is a reduction in porosity of 0.2% or more in the thickness facing portion 12 on the injection tip side of the molten aluminum. Is done.

<Bubble {Porosity} and Shrinkage {Shrinkage Cavity}>
Next, when the wall surface side of the cylinder forming first cylinder portion 15 of the facing portion 12 of the brake caliper of the comparative example and the embodiment is cut and the cut surface is observed, the comparative example is as shown in FIG. A large number of bubbles (porosity) appeared, and the largest one was 3 mm. Moreover, there was a shrinkage nest (shrinkage nest) due to condensation of the molten aluminum. In the comparative example, a plurality of bubbles (porosity) were also present in the region near the wall surface of the first cylinder portion 15.

On the other hand, as shown in FIG. 15, fine bubbles (porosity) appeared in the example, but in the region near the wall surface side of the first cylinder portion 15, bubbles (porosity) and shrinkage nests (shrinkage nests) There is almost no.

As described above, in the comparative example, a large number of bubbles (porosity) are generated in the thick facing portion 12 having the first cylinder portion 15 for cylinder formation, and contraction nests (shrinkage nests) are generated. There is a concern that internal defects that hinder the performance of the pressure vessel are likely to appear and the strength is also lowered.

On the other hand, in the example, since there are almost no air bubbles (porosity) and shrinkage nests (shrinkage nests) in the region near the wall surface side of the first cylinder portion 15, the processing accuracy can be improved. At the same time, the strength can be improved.

In place of the above-described embodiment, as shown in FIG. 11A (b), the injection of molten aluminum from the gate 18 is performed in a direction toward the wall surface on the cylinder forming first cylinder portion 15 side. Even in the caliper 10 manufactured, since the bubbles contained in the molten aluminum can be dispersed and refined, the porosity can be reduced as compared with the comparative example, and the bubbles (porosity) can be obtained. ) And shrinkage nests (shrinkage nests) can be suppressed.

DESCRIPTION OF SYMBOLS 10 Brake caliper 11

Hollow part

12, 13 Opposite part 14 Connection part 15 Cylinder formation 1st cylinder part 16 Cylinder formation 2nd cylinder part 17 Casting part 18 Gate 20 Cavity

Claims

A facing portion that faces the hollow portion that accommodates the disk, a connecting portion that connects both sides of the facing portion, and a first cylinder portion for forming a cylinder that is formed on one of the facing portions. A brake caliper manufacturing method comprising:
After filling the cavity of the mold with oxygen at a pressure higher than atmospheric pressure, the injection of molten aluminum from the gate is directed to the wall surface on the first cylinder part side of the thick part on both sides of the first cylinder part. A method for manufacturing a brake caliper, characterized by being directed toward a direction.
In the manufacturing method of the brake caliper according to claim 1,
The brake caliper comprises a first cylinder portion for forming a cylinder and a second cylinder portion for forming a cylinder on opposite sides of the opposite portions.
In the manufacturing method of the brake caliper according to claim 1 or 2,
The brake caliper further comprises a cast-out part through which a cooling medium provided in the facing part in which the first cylinder part is formed flows.
In the manufacturing method of the brake caliper according to claim 3,
A method for manufacturing a brake caliper, characterized in that the injection of molten aluminum from the molten metal gate is performed in a direction that rebounds from the cast-out portion toward a wall surface on the first cylinder portion side.
In the manufacturing method of the brake caliper according to any one of claims 1 to 4,
A method for manufacturing a brake caliper, characterized by injecting and injecting molten aluminum into a cavity of the mold in a state where a water-soluble release agent diluted with water is attached to the mold.
In the manufacturing method of the brake caliper according to claim 5,
The method for producing a brake caliper, wherein the water-soluble release agent is a silicon oil-based water-soluble release agent or a graphite-based water-soluble release agent.