Concave cavity piston mold with insert ring lower than oil duct

Abstract

The utility model discloses a concave cavity piston mould with an insert ring lower than an oil duct, which comprises an outer mould, a top mould, a salt core and an inner mould, the salt core is mounted on the inner mould, the outer mould is sleeved on the outer side of the inner mould, a plurality of guide slopes and insert ring positioning planes are arranged on the outer mould, a plurality of milling grooves are arranged on the top mould, and the insert ring positioning planes are arranged in the milling grooves. The milling grooves in the top die correspond to the guide slopes on the outer die in a one-to-one mode, the top die and the outer die are correspondingly assembled through the milling grooves and the guide slopes respectively, and the guide slopes and the insert ring positioning plane are connected to be arranged in the center area of the top of the outer die and are higher than the top of the salt core in position. The four guide slopes for mounting the insert ring are additionally arranged on the outer die, and the height starting points of the guide slopes are higher than the top of the salt core mounted on the die, so that the mounting space of the insert ring is increased, and the problem that the insert ring of the piston with the lower end face for mounting the insert ring lower than the upper plane of the salt core is difficult to mount is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical processing and manufacturing, in particular to a piston die with an inner concave cavity whose insert ring is lower than the height of an oil channel. Background Art

[0002] With the increase of engine power, boost load, reciprocating high speed and other parameters, aluminum silicon piston mainly adopts wear-resistant insert and internal cooling oil channel structure. Under normal conditions, the lower end surface of the wear-resistant insert in the piston is higher than the upper position of the cooling oil channel (such as Figure 5 As shown), so that the salt core and the insert can be easily and quickly installed during the piston casting production. However, for some pistons, the installation position of the lower end surface of the wear-resistant insert is lower than the upper position of the cooling oil channel (such as Figure 6 As shown in the figure, the piston cavity is concave and cannot be demolded as a whole. The piston mold of this structure is a 5-piece mold structure. The salt core is installed on the inner mold core. Due to the height of the large side core of the inner mold, the inner mold core drives the salt core downward for a short distance, and the salt core cannot be placed below the lower end surface of the insert ring. When the insert ring is installed during casting production, it collides with the salt core, causing the salt core to break or be damaged, and it is impossible to cast a qualified piston blank. To solve the problem of difficult installation of the insert ring of a piston whose lower end surface is lower than the upper plane of the salt core, it is necessary to improve the mold structure design of the internal cooling oil channel piston and improve the insert ring installation method to ensure the normal casting production of the piston blank. Utility Model Content

[0003] In order to solve the above problems, the utility model provides an inward concave cavity piston mold with an insert ring lower than the oil channel height, comprising an outer mold, a top mold, a salt core, and an inner mold. The salt core is installed on the inner mold, and the outer mold is sleeved on the outside of the inner mold. The outer mold is provided with multiple guide slopes and insert ring positioning planes, and the top mold is provided with multiple milling grooves. The milling grooves on the top mold correspond one-to-one to the guide slopes on the outer mold. The top mold and the outer mold are respectively assembled through the milling grooves and the guide slopes. The guide slopes are connected to the insert ring positioning plane and are arranged in the central area of ​​the top of the outer mold, and are higher than the top of the salt core.

[0004] Furthermore, there are specifically four guiding slopes, the inclination angle of the guiding slopes is 8°, and the starting point of the height of the guiding slopes is 8-13 mm higher than the top of the salt core.

[0005] Furthermore, the specific position where the salt core is installed on the inner mold is: the salt core is installed at a side core position close to the inner mold.

[0006] Furthermore, the downward movement range of the core of the inner mold is: 0-5mm.

[0007] Furthermore, a convex pressing block is provided on the top mold, and the convex pressing block is specifically provided on the inner side of the milling groove.

[0008] The utility model provides a piston mold with an inner concave cavity and an insert ring lower than the oil channel height, which has the following beneficial effects:

[0009] The utility model increases the space for installing the inlay ring by adding four guiding inclined surfaces for installing the inlay ring on the outer mold, and the starting point of the guiding inclined surfaces is higher than the top of the salt core installed on the mold, thereby solving the problem that the inlay ring of the piston whose lower end surface is lower than the upper plane of the salt core is difficult to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0011] Figure 1 A schematic diagram of the structure of the outer mold device provided by the utility model;

[0012] Figure 2 This is a schematic diagram of the top mold device structure provided by the utility model;

[0013] Figure 3 A schematic diagram of the salt core and inner mold structure provided by the utility model;

[0014] Figure 4 A schematic diagram of the structure of the device provided by the utility model during operation;

[0015] Figure 5 A schematic diagram of the structure in which the lower end surface of the wear-resistant insert provided by the utility model is installed higher than the upper position of the cooling oil channel in the prior art;

[0016] Figure 6 This is a structural diagram of the prior art in which the lower end surface of the wear-resistant insert is installed lower than the upper position of the cooling oil channel provided by the utility model.

[0017] In the figure, 1, outer mold; 2, top mold; 3, salt core; 4, inner mold; 1-1, guide slope; 1-2, inlaid ring positioning plane; 2-1, milling groove; 2-2, raised pressure block. DETAILED DESCRIPTION

[0018] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] The following describes the implementation method of the present invention in detail with reference to the accompanying drawings. The description only includes some embodiments, not all embodiments. For the purpose of clarity, representations and descriptions that are not related to the present invention are omitted in the drawings and descriptions.

[0020] To provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the following detailed description of the technical solution of the present invention is provided. Obviously, the implementation examples described are only a portion of the embodiments of the present invention, not all of them, and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without inventive effort are also within the scope of protection of the present invention.

[0021] The utility model aims to solve the problem of not colliding and damaging the salt core when installing the wear-resistant insert ring during the casting process of the inner cooling oil channel piston blank, so as to cast a qualified piston blank.

[0022] like Figure 1 、 Figure 2 、 Figure 3 As shown, the utility model provides an inward concave cavity piston mold with an insert ring lower than the oil channel height, comprising an outer mold 1, a top mold 2, a salt core 3, and an inner mold 4. The salt core 3 is installed on the inner mold 4, and the outer mold 1 is sleeved on the outside of the inner mold 4. The outer mold 1 is provided with a plurality of guide slopes 1-1 and an insert ring positioning plane 1-2, and the top mold 2 is provided with a plurality of milling grooves 2-1. The milling grooves 2-1 on the top mold 2 correspond to the guide slopes 1-1 on the outer mold one by one. The top mold 2 and the outer mold 1 are respectively assembled through the milling grooves 2-1 and the guide slopes 1-1. The guide slopes 1-1 are connected to the insert ring positioning plane 1-2 and are arranged in the top center area of ​​the outer mold 1, and are higher than the top of the salt core 3.

[0023] Specifically, there are four guiding slopes 1 - 1 , and the inclination angle of the guiding slopes 1 - 1 is 8°. The starting point of the height of the guiding slopes 1 - 1 is 8-13 mm higher than the top of the salt core 3 .

[0024] The specific position of the salt core 3 installed on the inner mold 4 is: the salt core 3 is installed at the edge core position close to the inner mold 4; the downward movement range of the center core of the inner mold 4 is: 0-5mm.

[0025] A convex pressing block 2-2 is provided on the top mold 2, and the convex pressing block 2-2 is specifically provided on the inner side of the milling groove 2-1.

[0026] Example: Figure 4As shown, a PID piston with a cylinder diameter of Φ91 is selected for mold improvement design. The outer mold 1 is increased with four guide slopes 1-1 for installing the inserts, with a slope of 8°, and the starting height of the guide slope 1-1 is 8mm higher than the top of the salt core 3 installed on the mold; the top mold 2 has a milling groove 2-1 corresponding to the matching part with the outer mold 1, and retains a raised pressure block 2-2 for pressing the inserts; during the piston casting production process, before installing the inserts, the core of the inner mold 4 drives the salt core 3 to move down 5mm. Because the large side core of the inner mold 4 cannot move up and down, the distance that the core of the inner mold 4 drives the salt core 3 to move down is limited. According to calculation, it can move down 5mm. When installing the inserts, the robot gripper tries to get as close as possible to the top position of the salt core 3 installed on the mold, and releases the insert in the air. The insert falls into the insert positioning plane 1-2 through the self-centering of the guide slope 1-1 of the outer mold 1, and is then pressed by the raised pressure block 2-2 of the top mold 2.

[0027] After the mold structure is improved, the insert ring can be quickly pressed onto the outer mold insert ring positioning plane, thereby ensuring that the position and size of the piston insert ring being cast are qualified, and solving the problem that the piston insert ring is difficult to install when the lower end surface of the insert ring is lower than the upper plane of the salt core.

[0028] Before the improvement, piston blanks could not be produced due to the inability to install the piston ring. After the improvement, verification was conducted on five PID76 molds where the oil passage was positioned higher than the ring. PID76 product casting produced 2,400 piston blanks. After processing into finished pistons, statistics showed that 18 pistons were rejected due to ring misalignment, and 6 pistons were rejected due to ring bonding flaw detection. The casting scrap rate for ring misalignment was 0.75%, and the flaw detection scrap rate for ring bonding was 0.25%. Based on big data statistics, the casting scrap rate for conventional ring-mounted pistons was 0.6%, and the flaw detection scrap rate for ring misalignment was 0.3%. The difference between the rejection rates for ring misalignment and ring bonding flaw detection was very small, both falling within the normal fluctuation range, indicating that the mold structure improvement was successful.

[0029] When the robot gripper installs the ring, it drops the ring near the top of the salt core. The ring falls into the ring positioning platform through self-centering through the outer mold guide slope, and is pressed tightly by the top mold raised pressure block to ensure that the position and size of the casting piston ring are qualified.

[0030] The utility model increases the space for installing the inlay ring by adding four guiding inclined surfaces for installing the inlay ring on the outer mold, and the starting point of the guiding inclined surfaces is higher than the top of the salt core installed on the mold, thereby solving the problem that the inlay ring of the piston whose lower end surface is lower than the upper plane of the salt core is difficult to install.

[0031] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the concept described herein through the above teachings or techniques or knowledge in the relevant fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the claims appended hereto.

Claims

1. A concave cavity piston mold with an insert ring lower than the height of the oil channel, comprising an outer mold (1), a top mold (2), a salt core (3), and an inner mold (4), wherein the salt core (3) is mounted on the inner mold (4), and the outer mold (1) is sleeved on the outer side of the inner mold (4), characterized in that: The outer mold (1) is provided with a plurality of guide bevels (1-1) and a ring-inserted positioning plane (1-2), and the top mold (2) is provided with a plurality of milling grooves (2-1). The milling grooves (2-1) on the top mold (2) correspond one-to-one to the guide bevels (1-1) on the outer mold. The top mold (2) and the outer mold (1) are respectively assembled through the milling grooves (2-1) and the guide bevels (1-1). The guide bevels (1-1) are connected to the ring-inserted positioning plane (1-2) and are arranged in the center area of ​​the top of the outer mold (1), and are located higher than the top of the salt core (3).

2. The concave cavity piston mold with the insert ring lower than the oil channel height according to claim 1, characterized in that: Specifically, there are four guide slopes (1-1), the inclination angle of the guide slopes (1-1) is 8°, and the starting point of the height of the guide slopes (1-1) is 8-13 mm higher than the top of the salt core (3).

3. The concave cavity piston mold with the insert ring lower than the oil channel height according to claim 1, characterized in that: The specific position at which the salt core (3) is installed on the inner mold (4) is: the salt core (3) is installed at a side core position close to the inner mold (4).

4. The piston mold with a concave cavity and an insert ring lower than the oil channel height according to claim 1, characterized in that: The downward movement range of the center core of the inner mold (4) is: 0-5mm.

5. The piston mold with a concave cavity and an insert ring lower than the oil channel height according to claim 1, characterized in that: A raised pressing block (2-2) is provided on the top mold (2), and the raised pressing block (2-2) is specifically provided on the inner side of the milling groove (2-1).

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