JPH10328811A - How to attach molded body to bore insert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the development of compressed shearing crack and peripheral crack in a formed body even in the cross of loading molten metal pressure to the formed body from the outer peripheral surface at the time of pouring the molten metal by inserting the formed body onto a bore insert at a prescribed pressure and pushing so that the formed body does not comes out from the formed body inserting side under inserting condition. SOLUTION: The formed body 2 is inserted onto the bore insert 1 at a prescribed pressure from a fixed die 3a side by using an inserting machine and held in the axial direction under this condition. The first pins 14 are abutted on the formed body 2 from the opposite side (a movable die 3b side) to the formed body inserting side under this condition, and the advancing end in the inserting direction is positioned and the first pins 14 are locked under this condition and successively, the formed body 2 is pushed toward the formed body inserting direction from the fixed die 3a side (formed body inserting side) by e.g. springs 13 and the second pins 12 energized with cylinder, etc. Since the formed body 2 is held by pushing with the first pins 14 and the second pins 12, after retreating the inserting machine, the formed body 2 is not loosened by shifting in the axial direction at the time of pouring the molten steel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a reinforcing fiber molded body to a bore insert in a method for manufacturing a cylinder block of a type in which the inner surface of a cylinder bore is formed of a metal matrix composite material (MMC).

[0002]

2. Description of the Related Art Conventionally, a method for manufacturing a cylinder block in which the inner surface of a cylinder bore is made of a metal matrix composite material is shown in FIG.
As shown in FIG.
1, a pre-heated, pre-heated, molded body 102 of a straight shape whose inner periphery is tapered and whose outer periphery is parallel to the axis is arranged.
The bore insert in which the compact is placed is placed in the cavity 104 in the mold 103, and then the molten metal 105 is poured into the cavity 104 by the injection cylinder 106, and is injected and pressed by the plunger tip 107 to form the compact 102. The molten metal is impregnated into the molded body 102 only from the outer peripheral side of the mold to make the molded body part a metal-based composite material. After cooling, the cylinder block product is removed from the mold 103 and the bore insert 101 and taken out. The inner surface of the cylinder bore is machined to form a cylinder bore of a straight cylindrical surface having a predetermined dimension.

[0003]

However, the conventional method of manufacturing a cylinder block has the following problems. In the conventional manufacturing method, some clearance 108 always occurs between the bore insert 101 and the molded body 102 as shown in FIG. The clearance 108 is, for example,
This is caused by the tolerance between the taper angle of 1 and the taper angle of the molded body 102, and the temperature variation between the bore insertion temperature (for example, 100 to 200 ° C.) and the molded body temperature (for example, 500 to 900 ° C.). In the presence of the clearance 108, pressure is applied to the molten aluminum to form the compact 102.
When the molten aluminum is impregnated with the molten aluminum, the molded body 102 generates a compression shear crack 109 as shown in FIG. That is,
When the circumferential compressive stress generated in the molded body 102 due to the pressure from the outer periphery exceeds the allowable shear stress, the direction of the compressive force is increased by 45%.
The shear fracture occurs along the plane of °, buckling occurs along the fracture plane, and a locally high-density portion of the reinforcing fiber of the molded body occurs. If this part slides with the piston ring in actual use, the wear of the piston ring increases. Also,
In general, the molded body 102 is obtained by immersing a gas-permeable mold in a slurry mixed with reinforcing fibers, sucking the inside of the gas-permeable mold, laminating and forming the reinforcing fibers on the surface of the gas-permeable mold, and drying the molded body. Because it is manufactured by a method that pulls out a breathable mold,
In the molded body 102, the reinforcing fibers are oriented in the circumferential direction and are laminated in the thickness direction (Baumkuchen shape), and the interlayer strength is relatively weak. Therefore, the above-described cracks 109 due to the compression shear propagate in the circumferential direction in the middle of the thickness direction to generate circumferential cracks 110 (FIG. 11), in which the molten metal intrudes and solidifies, and when this portion is exposed during processing, As shown in FIG. 12, a portion 111 having no reinforcing material locally occurs. If such a portion 111 exists, abnormal wear or seizure of the piston ring occurs during actual use. An object of the present invention is to eliminate the gap between the peripheral surface of the molded body and the outer peripheral surface of the bore insert, and to cause the molded body to undergo compression shear cracking and circumferential cracking when molten metal pressure is applied to the molded body from the outer peripheral surface. It is an object of the present invention to provide a method of mounting a molded body on a bore insert which can be prevented.

[0004]

The present invention to achieve the above object is as follows. (1) A step of inserting the molded body into the bore insert at a predetermined pressure, and a step of pressing the molded body so as not to get out of the molded body from the molded body insertion side in the inserted state. Mounting method. (2) A step of inserting the molded body into the bore insert at a predetermined pressure, and a step of positioning a forward end in the insertion direction by applying a first pin to the molded body from at least the side opposite to the molded body insertion side in the inserted state. And pressing the molded body from the molded body insertion side with a second pin urged in the molded body insertion direction in the inserted state, and mounting the molded body to the bore insert.

In the method (1) for mounting the molded body on the bore insert, the molded body is inserted into the bore insert at a predetermined pressure, so that the clearance between the inner peripheral surface of the molded body and the outer peripheral surface of the bore insert is reduced. Gone,
In this state, since the pressing is performed from the insertion side, the state of the gap 0 is maintained without applying excessive or insufficient axial force to the molded body, and when the molten metal is poured, even if the molten metal pressure is applied from the outer peripheral surface to the molded body. On the other hand, the compact does not generate compression shear cracks and circumferential cracks. In the method of mounting the molded body on the bore insert of the above (2), since the molded body is inserted into the bore insert at a predetermined pressure, there is no gap between the peripheral surface of the molded body and the outer peripheral surface of the bore insert. In this state, it is positioned with a pin from the opposite direction to the insertion and pressed with a biasing pin from the insertion side, so that the state of gap 0 is maintained without applying excessive or insufficient axial force to the molded body, and when the molten metal is poured, Even if a molten metal pressure is applied to the body from its outer peripheral surface, the formed body does not generate compression shear cracks and circumferential cracks.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a method of manufacturing a cylinder block including a method of mounting a molded body on a bore insert of the present invention in the order of steps, and FIG. 3 and 4 are graphs showing the allowable range of the distance between the movable die and the molded body in the mounting method of FIG.
FIG. 3 shows a method of mounting the molded body of the embodiment to the bore insert.
(Common to the first and second embodiments), FIGS. 5 to 7 show a method of mounting a molded body to a bore insert according to a second embodiment of the present invention. Components common or similar throughout all embodiments of the present invention are denoted by the same reference numerals throughout all embodiments of the present invention.

First, a method of manufacturing a cylinder block including a method of mounting a molded body on a bore insert according to the present invention will be described with reference to FIG. In the method for manufacturing a cylinder block according to the present invention, the pre-heated, substantially cylindrical molded body 2 having the inner and outer peripheral surfaces 2a and 2b is brought into contact with the outer peripheral surface 1a of the bore insert 1 having the outer peripheral surface 1a, A first step of disposing in a cavity 4 of a mold 3 composed of a mold 3b and a fixed mold 3a, pouring a molten metal 5 into a cavity 4 and applying molten metal pressure to the molded body 2 from an outer peripheral surface 2b of the molded body 2 And a second step of impregnating the molten metal 5 to composite the molded body 2. The method for mounting the molded body of the present invention on the bore insert is included in the first step,
The gap 8 between the inner peripheral surface 2a of the molded body 2 and the outer peripheral surface 1a of the bore insert 1 is made substantially zero.

In the above-described method for manufacturing a cylinder block, the cylinder block coarse material 9 is further cooled after the molten metal is solidified.
And a third step of removing from the bore insert 1 and taking out the cylinder bore inner surface 10 formed as a metal matrix composite material 9a.
May be machined to form a cylinder bore of a straight cylindrical surface having a predetermined dimension.

In FIG. 1, reference numeral 6 denotes an injection cylinder for injecting and pressing the molten metal into the cavity 4, and reference numeral 7 denotes a plunger tip of the injection cylinder. In the illustrated apparatus, the bore insert 1 and the molded body 2 are arranged so as to be in the vertical direction, but may be a horizontal mold. The molten metal 5 is, for example, an aluminum molten metal (however, it is not limited to the aluminum molten metal).

In the above-described method for manufacturing a cylinder block, the relationship between the change in melt pressure and the start and completion of impregnation in the second step is as follows. During a predetermined period from the start of the pouring of the molten metal, the pressure of the molten metal hardly increases while the cavity is being filled with the molten metal. When the molten metal fills the cavity, the molten metal pressure starts to rise suddenly, and about 75
0 to 850 kg / cm ² (73.5 to 83.3 MPa)
Reach Then, at an initial stage where the pressure rises from the pressure sudden increase starting point, about 3 to 30 kg / cm ² (0.294
At about 2.94 MPa), impregnation of the molten metal into the molded body is performed and completed. When a molten metal pressure is applied only to the outer peripheral surface of the compact in a state where a gap exists as in the related art, about 3 kg / c
Although compression shear occurs in the molded body at m ² (0.294 MPa), in the present invention, the molded body 2 is supported by the bore insert 1 so as to eliminate the gap 8 in the first step. No shear cracks or circumferential cracks occur.

Next, a description will be given of a portion common to the embodiments of the method of mounting the molded body 2 to the bore insert 1 (included in the first step) and the operation thereof according to the present invention. The method of mounting the molded body 2 on the bore insert 1 according to the present invention is performed by using the insert machine 11 to convert the molded body 2 having the tapered inner peripheral surface 2a to the bore insert 1 having the tapered outer peripheral surface 1a from the side of the fixed mold 3a. A step of inserting at a predetermined pressure and holding the molded body 2 in the axial direction in that state.

In the insertion step, as shown in FIG. 2, the insertion is stopped when the pressure for inserting the molded body 2 of the insert machine 11 suddenly rises (when the molded body 2 comes into contact with the bore insert 1). At this point, the front end of the molded body 2 in the insertion direction and the movable mold 3b
Can have a certain range (A) because the molded body 2 has a tolerance due to crushing. In the range (A) where the distance is larger than the range (A), the molded body 2 and the bore A gap 8 is formed between the mold body 1 and the melt 2 during the pouring of the molten metal, and the mold body 2 and the bore insert 1 are tightened in the range (c) where the distance is smaller than the range (a). When the molded body 2 is fitted and cooled and contracts, it cannot be absorbed by the collapse of the molded body 2 and the molded body 2 breaks. In the state in the range of (a), the molded body 2 is held and fixed in the axial direction.

The operation of the common part is described in the following.
Is in a state where there is no gap 8 in the bore insert 1, and in this state, the molten metal is poured in the second step, so that even if the molten metal pressure is applied from the outer peripheral surface 2b of the molded body 2, the molded No directional crack propagation occurs.

Next, a part unique to each embodiment of the method of mounting the molded body 2 to the bore insert 1 of the present invention and its operation will be described. In the method of the first embodiment of the present invention, as shown in FIG. 3, after the molded body is inserted into the bore insert at a predetermined pressure (a pressure within a range of the above (A)), the molded body is kept in this state. FIG.
As shown in (2), the molded body 2 is pressed from the molded body insertion side (the fixed mold 3a side) so as not to come out of the bore insert 1 (to move in the loosening direction). The presser may be pressed by the fixed die 3a itself, or may be pressed by the pin 12 protruding from the fixed die 3a toward the molded body 2. Also,
The pin 12 may be urged at a predetermined pressure toward the molded body 2 by a spring 13 or a cylinder so that excessive force is not applied to the molded body 2 and the pin 12 does not enter the region (c).

The operation of the first embodiment is as follows. After the molded body is inserted into the bore insert at a predetermined pressure, the molded body 2 is pressed and held. 2 is not loosened due to the axial movement of the molded body 2, no gap is formed between the molded body 2 and the bore insert 1 due to the loosening, and even if the molten metal pressure is applied from the outer peripheral surface 2 b of the molded body 2 Does not cause compression shear cracking and circumferential crack propagation.

In the method according to the second embodiment of the present invention, as shown in FIG.
5), and in this state, as shown in FIG. 5, the side opposite to the molded body insertion side (movable mold 3).
b), the first pin 14 is applied to the molded body 2 to position the forward end in the insertion direction, and the first pin 14 is locked in that state. Then, the molded body is moved from the fixed mold 3a side (molded body insertion side). 2 is pressed in the molded body insertion direction by the second pin 12 urged by, for example, a spring 13 or a cylinder.

The operation of the second embodiment is as follows. After the molded body is inserted into the bore insert at a predetermined pressure, the molded body 2 is connected to the first pin 1.
4. Secondly, since the insert 12 is pressed down and held by the pin 12, the molded body 2 does not move in the axial direction when the molten metal is poured after the insert machine 11 retreats and does not loosen. There is no gap between the chips 1 and the compact 2 does not cause compression shear cracking and circumferential crack propagation even when the molten metal pressure is applied from the outer peripheral surface 2b of the compact 2.

[0018]

According to the first aspect of the present invention, since the molded body is inserted into the bore nest at a predetermined pressure, the molded body is inserted into the bore nest at a predetermined pressure. Gap is eliminated, and in this state, the state of the gap 0 is maintained without applying excessive or insufficient axial force to the molded body (it does not become the area of (A) or (C)), and the molten metal is removed. When the molten metal is poured from the outer peripheral surface of the molded body during pouring, the molded body does not undergo compression shear cracking and circumferential cracking. According to the method of mounting the molded body on the bore insert according to claim 2, since the molded body is inserted into the bore insert at a predetermined pressure, there is no gap between the inner peripheral surface of the molded body and the outer peripheral surface of the bore insert. In this state, the pin is positioned in the opposite direction to the insertion and pressed by the urging pin from the insertion side, so that the state of the gap 0 is maintained without applying excessive or insufficient axial force to the molded body, and when the molten metal is poured, Even if a molten metal pressure is applied to the molded body from the outer peripheral surface, the molded body does not generate compression shear cracks and circumferential cracks.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a method of manufacturing a cylinder block including a method of attaching a molded body to a bore insert of the present invention is performed in the order of steps.

FIG. 2 is a diagram illustrating a relationship between a distance between a movable mold and a molded body and a fitted state when the molded body is mounted on a bore insert.

FIG. 3 is a cross-sectional view showing a step of inserting a molded body into a bore insert according to the first and second embodiments of the present invention.

FIG. 4 is a cross-sectional view showing a pressing step of the compact according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a step of positioning a formed body according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a step of pressing a compact according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view taken along a plane perpendicular to the axial direction of a molded body according to the first and second embodiments of the present invention.

FIG. 8 is a sectional view of an apparatus for performing a conventional method of manufacturing a cylinder block.

FIG. 9 is a sectional view of a bore insert and a formed body in a conventional method.

FIG. 10 is a cross-sectional view of a part of a molded body showing compression shearing of the molded body in a conventional method.

FIG. 11 is a cross-sectional view of a part of a formed body showing a circumferential crack of the formed body in a conventional method.

FIG. 12 is a perspective view of a part of a formed body showing a state in which a circumferential crack portion of the formed body is exposed at the time of processing in a conventional method.

[Explanation of symbols]

 Reference Signs List 1 bore insert 1a bore insert outer peripheral surface 2 molded body 2a molded inner peripheral surface 3 mold 3a fixed mold 3b movable mold 4 cavity 5 molten metal 8 gap 11 insert machine 12 pin (fixed mold side, second pin) 13 spring 14 Pin (movable side, first pin)

Continued on the front page (72) Inventor Manabu Fujine 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hiroto Yamazaki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Masuo Shimizu 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (2)

[Claims] 1. A process for inserting a molded body into a bore insert at a predetermined pressure, and a step for pressing the molded body from the insertion side of the molded body so that the molded body does not come out of the bore insert. How to attach to. 2. A step of inserting the molded body into the bore insert at a predetermined pressure, and a step of inserting the molded body into the molded body from the side opposite to the molded body insertion side in the inserted state.
A step of positioning the forward end in the insertion direction by contacting a pin of the molded body; and a step of pressing the molded body from the molded body insertion side by a second pin urged in the molded body insertion direction in a state where the molded body is inserted,
A method for mounting a molded body consisting of