The method of assembly of the piston with a reinforcing insert

 

(57) Abstract:

The invention relates to the Assembly of the pistons of internal combustion engines and can be used in the repair and restoration of the pistons. In the body of the piston performs a groove with a cross section in the shape of a trapezoid, the smaller base of which is the bottom of the grooves having smooth transitions to its end sides, which are the sides of a trapezoid. Smaller base of the trapezoid is performed in the form of direct or at least one protrusion in the middle part. Insert in the form of a continuous ring is placed on the platform and press it. Using Cam press box on the platform vidvigayt in the groove of the piston. Then the platform is removed and pressed the insert in the groove of the piston in several stages. At all stages of pressing the paste is applied evenly around their circumference effort. The result is a reliable connection of the piston with a reinforcing insert for pistons of wrought aluminum alloys, and cast pistons made of aluminum alloys. 3 Il.

The invention relates to the Assembly the Assembly of the pistons of internal combustion engines, in particular, can b the reinforcing insert, namely, that in the ring groove of the piston, install reinforcing insert and deform it, working alternately in odd and even parts of the perimeter of the insert, with the subsequent application of this effort simultaneously to all areas of the insert to fill the grooves in the piston in the axial and radial directions of the material of the insert (US 749013, 20.09.1999, B 23 P 19/02).

The disadvantage of this method is that to achieve a complete filling of the grooves in the piston insert almost impossible, as when "hard" insert there are high voltage, forming microcracks and, as a consequence, the destruction of the piston. This is especially true for cast pistons of aluminum alloy (AL-16, AL-26 and other ). Positive results were obtained only for forged pistons from wrought aluminium alloys (AK-2, AK-4).

There is a method of Assembly of the piston with a reinforcing insert, including installation of inserts in the form of a continuous ring in the groove made in the body of the piston, and the press-fit insertion in the specified groove in several stages (EN 2001729 C1, 30.10.1993, 23 P 15/10).

The inner surface of the insertion with beveled edges, or at least one protrusion is ressouce to insert spare-changing on its circumference effort, the maximum value of which exceeds the yield strength of the material of the piston.

The disadvantage of this method is the necessity of creating an uneven effort that adds cost and complexity to a method and apparatus for its implementation. In addition, this method can only be applied to the pistons of wrought aluminum alloys. The objective of the invention to achieve a simple and cheap way reliable connection of the piston with a reinforcing insert for pistons of wrought aluminum alloy and cast pistons of aluminum alloy.

To solve the problem in a well known method of Assembly of the piston with a reinforcing insert, including installation of inserts in the form of a continuous ring in the groove made in the body of the piston, and the press-fit insertion in the specified groove in several stages, the groove comply with the cross-section in the shape of a trapezoid, the smaller base of which is the bottom of the grooves having smooth transitions to its end sides, which are the lateral sides of the trapezoid, while the smaller base of the trapezoid is performed in the form of direct or at least one protrusion in the middle part, perform inserts with cross-section in the shape of a trapezoid, installation insert the t to her, during installation, insert it vidvigayt in the groove of the piston with the Cam press, after which the platform is removed and the press-fit insertion is carried out with application at all stages of the uniform around the circumference of the insertion efforts.

In Fig. 1 presents the groove cross-section, in Fig. 2 is a cross section of the insert Assembly with the piston of Fig. 3 - start of Assembly of the piston with a reinforcing insert.

The piston Assembly with a reinforcing insert is as follows.

The piston 1 (Fig. 1 and 2) in the place of installation insert 2 perform the groove bottom 3 which has smooth transitions to its end sides 4 and 5. The groove in cross section is performed in the form of a trapezoid, the smaller base of which is the bottom 3 of the groove. The end faces 4 and 5 are lateral sides of the trapezoid. Smaller base of the trapezoid is performed in the form of direct for pistons of wrought aluminum alloys, or at least one protrusion 6 in the middle for the cast pistons of aluminum alloys (Fig. 1).

The insert 2 is carried out in the form of a continuous ring having a cross-sectional shape of a trapezoid.

Box 2 mounted on the platform 7 and press it to the platform 7 by using, for example, pressing the 3. Next, remove the platform 7 and pressed the insert 2 into the groove of the piston 1 in several stages. At each subsequent stage of pressing the piston 1 box 2 rotates around the axis of the piston relative to the Cams 8 of the press. At all stages of pressing the paste is applied evenly around the circumference of the insertion force. In the case of assembling the cast pistons (Fig. 2) tab 6 helps to reduce the stresses in the corners of the grooves due to the formation of gaps.

The claimed method allows for the insertion of inexpensive steel, because of differences in the coefficients of linear expansion of steel and aluminum alloy piston is offset trapezoidal form of the insert and the groove, and clearances.

The reliability of fixing of the insert and the piston in the radial and circumferential directions is provided trapezoidal shape of the connected parts, which allows the injection of uniform effort at all stages. This not only simplifies the process of pressing, but also helps to avoid stress in places of contact of the yield stress of the material of the piston.

The method of Assembly of the piston with a reinforcing insert, including installation of inserts in the form of a continuous ring in the groove made in taut with a cross-section in the shape of a trapezoid, smaller base of which is the bottom of the grooves having smooth transitions to its end sides, which are the lateral sides of the trapezoid, while the smaller base of the trapezoid is performed in the form of direct or at least one protrusion in the middle part, perform inserts with cross-section in the shape of a trapezoid, the installation of the insert into the groove of the piston is performed using the platform on which the insert is pre-placed and pressed against her, in the installation process, insert it vidvigayt in the groove of the piston with the Cam press, after which the platform is removed, and the press-fit insertion is carried out with application at all stages of the uniform around the circumference of the insertion efforts.

 

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