CN114054680A

CN114054680A - Single-cavity die for feeding riser and large-cylinder-diameter piston

Info

Publication number: CN114054680A
Application number: CN202111307149.0A
Authority: CN
Inventors: 余明; 李敏; 陈凤娇
Original assignee: ANHUI HIGH-TECH POWER TECHNOLOGY CO LTD
Current assignee: ANHUI HIGH-TECH POWER TECHNOLOGY CO LTD
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2022-02-18

Abstract

The invention provides a large-cylinder-diameter piston which comprises a die body, wherein a cavity, a main pouring gate and a riser are sequentially arranged in the die body from inside to outside, and the main pouring gate is horizontally arranged; the riser is obliquely arranged, and the horizontal height of one end far away from the main pouring gate is higher than that of the other end; a large-cylinder-diameter piston is obtained by casting any one of the single-cavity molds with feeding heads; the piston comprises a piston body, a pouring gate material and a riser material, wherein the piston body, the pouring gate material and the riser material are sequentially connected, the pouring gate material is horizontally arranged, the riser material is obliquely arranged, and the horizontal height of one end far away from the pouring gate material is higher than the horizontal height of one end connected with the pouring gate material; the invention has the beneficial effects that: the main pouring channel is arranged horizontally, so that the phenomenon that the temperature of the main pouring channel is changed unevenly due to the backflow and overheating of molten aluminum in the cavity is avoided, and the skirt part is formed more stably; the riser is inclined, so that the fluidity of the molten aluminum is improved; at the same time, the volume of the riser is increased, so that the temperature of aluminum at the position is reduced slowly to improve the feeding effect.

Description

Single-cavity die for feeding riser and large-cylinder-diameter piston

Technical Field

The invention relates to the technical field of piston machining, in particular to a single-cavity die for feeding a shrink head and a large-cylinder-diameter piston.

Background

The main function of the piston is to take up the gas pressure in the cylinder and to transmit this force to the connecting rod via the piston pin in order to push the crankshaft in rotation. The top of the piston, the cylinder cover and the cylinder wall jointly form a combustion chamber. The working condition of the piston is quite bad, firstly, the piston bears a large mechanical load, and a huge reciprocating motion inertia force can be generated during high-speed motion, and the inertia force can reach hundreds of times or even higher than the weight of the piston; secondly, it bears higher thermal load, the top of the piston is directly contacted with high temperature gas periodically, the highest temperature of the gas can reach more than 2000K, therefore, the temperature of the piston is also very high. Meanwhile, the piston is severely worn when moving at high speed.

In order to ensure good running characteristics of the engine, the following requirements are made on the properties of the piston alloy material: low density, low thermal expansion coefficient, good wear resistance, excellent heat conductivity and processability. For this reason, the piston material currently used for engines is aluminum alloy.

The forming method of the aluminum alloy mainly comprises forging and casting, as shown in fig. 2, the cast piston comprises a piston body 21, a pouring material 22 and a dead head material 23, and the piston body 21, the pouring material 22 and the dead head material 23 are connected in sequence. The cast piston has less strength reduction at high temperature and low manufacturing cost, but in the cooling and solidification process of the cast, because of the liquid shrinkage and solidification shrinkage of the alloy, the cast is often hollow at the position of final solidification. The large and concentrated voids are called shrinkage cavities, and the fine and dispersed voids are called shrinkage porosity. The shrinkage cavity and the shrinkage porosity both reduce the actual strength of the casting, on one hand, the effective stressed sectional area of the casting is reduced due to the shrinkage cavity and the shrinkage porosity, and on the other hand, the stress concentration phenomenon is generated near the shrinkage cavity and the shrinkage porosity, so that the metal strength of the part is greatly weakened. Long-term production practical experience shows that the method of riser feeding is adopted to prevent the casting from generating shrinkage cavity and shrinkage porosity, and the method is an effective technological measure. The main function of the riser is to store enough liquid alloy so that the shrinkage of the casting during cooling and solidification can be continuously compensated, thereby preventing shrinkage cavities and shrinkage porosity in the casting. In addition, the riser also has the functions of air outlet, scum and the like. Therefore, the main problem of reasonably designing a pouring structure and improving the casting quality of the piston as much as possible is that the pouring structure faces the piston.

As shown in fig. 1, the single-cavity mold in the prior art includes a mold body 1, and a cavity 11, a main runner 12, and a riser 13 are sequentially disposed in the mold body 1 from inside to outside. At present, when an aluminum alloy piston is cast, a pouring structure with a single riser is adopted, and due to the fact that the riser is low in position, the exhaust and feeding effects are poor, the defects of shrinkage cavity, shrinkage porosity and the like of a piston skirt cannot be overcome, the strength of the piston skirt is low, and the machining and using performance of the piston are affected.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a single-cavity die for feeding a shrink head and a large-cylinder-diameter piston.

The invention solves the technical problems through the following technical means:

the single-cavity die for feeding the riser comprises a die body, wherein a die cavity, a main pouring gate and the riser are sequentially arranged in the die body from inside to outside, and the main pouring gate is horizontally arranged; the riser is arranged in an inclined mode, and the horizontal height of one end, far away from the main pouring gate, of the riser is higher than that of the other end of the riser.

As an improvement of the technical scheme, the inclination angle of the riser is set to be 15-20 degrees.

As an improvement of the technical scheme, the depth of the riser is set to be 20 mm.

As an improvement of the technical scheme, heat-insulating holes are uniformly distributed on two sides of the riser, and heat-insulating cotton is filled in the heat-insulating holes.

As an improvement of the technical scheme, the diameter of the heat-preservation hole is set to be 8mm, and the depth of the heat-preservation hole is set to be 15 mm.

A large-cylinder-diameter piston obtained by casting with the single-cavity die with the feeding head; including the piston body, water material and rising head material, the piston body, water material and rising head material connect gradually, it is the level setting to water the material, the rising head material is the slope setting, and keeps away from the level that waters material one end and be higher than with the level that waters the material and be connected one end.

The invention has the beneficial effects that: the main pouring gate is arranged to be horizontal, so that the phenomenon that the temperature of the main pouring gate changes unevenly due to the backflow and overheating of molten aluminum in a cavity is avoided, the piston skirt is formed more stably, and the phenomenon that a casting is scrapped due to the shortage of materials is avoided; the riser is inclined, so that the fluidity of the molten aluminum is improved; meanwhile, the volume of the feeder is increased (the depth is adjusted to be 20mm), and the increase of the capacity of the feeder slows down the temperature reduction of aluminum at the position so as to improve the feeding effect of the piston skirt.

Drawings

FIG. 1 is a schematic view of a prior art single cavity mold;

FIG. 2 is a schematic diagram of a piston according to the prior art;

FIG. 3 is a schematic structural view of a single-cavity mold of a feeding head according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a large-bore piston according to an embodiment of the present invention;

the mold comprises a mold body 1, a cavity 11, a main pouring gate 12, a riser 13, a heat insulation hole 14, a piston body 21, a pouring gate material 22 and a riser material 23.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Examples

As shown in fig. 3, the single-cavity mold with a feeding head of the present embodiment includes a mold body 1, and a cavity 11, a main runner 12 and a feeding head 13 are sequentially disposed in the mold body 1 from inside to outside, where the main runner 12 is disposed horizontally; the riser 13 is arranged in an inclined manner, and the horizontal height of one end far away from the main pouring gate 12 is higher than that of the other end.

The main pouring gate 12 is arranged to be horizontal, so that the phenomenon that the temperature of the main pouring gate 12 changes unevenly due to the backflow overheating of molten aluminum in the cavity 11 is avoided, the piston skirt is formed more stably, and the phenomenon that a casting is scrapped due to the shortage of materials is avoided; the riser 13 is arranged to be inclined, so that the fluidity of the molten aluminum is improved; at the same time, the volume of the riser 13 is increased (the depth is adjusted to be 20mm), and the volume of the riser 13 is increased, so that the temperature aluminum temperature is reduced slowly at the position to improve the feeding effect of the piston skirt.

The inclination angle of the dead head 13 is set to be 15-20 degrees.

The depth of the riser 13 was set to 20 mm.

Heat-insulating holes 14 are uniformly distributed on two sides of the riser 13, heat-insulating cotton is filled in the heat-insulating holes 14, and the phenomenon that the feeding effect is reduced due to the fact that the temperature of aluminum water in the riser 13 is reduced too fast is avoided.

The diameter of the heat preservation hole 14 is set to be 8mm, and the depth is set to be 15 mm.

As shown in fig. 4, a large-bore piston is obtained by casting using a single-cavity mold with a feeding head as described in any one of the above; including piston body 21, water material 22 and rising material 23, piston body 21, water material 22 and rising material 23 connect gradually, it is the level setting to water material 22, rising material 23 is the slope setting, and keeps away from the level that waters material 22 one end and be higher than the level of being connected one end with watering material 22.

It is noted that, in this document, relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. Single chamber mould with feeding riser, its characterized in that: the injection molding die comprises a die body (1), wherein a cavity (11), a main pouring gate (12) and a riser (13) are sequentially arranged in the die body (1) from inside to outside, and the main pouring gate (12) is horizontally arranged; the riser (13) is obliquely arranged, and the horizontal height of one end far away from the main pouring gate (12) is higher than that of the other end.

2. The single-cavity mold with after-feeding reservoir of claim 1, wherein: the inclination angle of the dead head (13) is set to be 15-20 degrees.

3. The single-cavity mold with after-feeding reservoir of claim 1, wherein: the depth of the riser (13) is set to be 20 mm.

4. The single-cavity mold with after-feeding reservoir of claim 1, wherein: heat-insulating holes (14) are uniformly distributed on two sides of the riser (13), and heat-insulating cotton is filled in the heat-insulating holes (14).

5. The single-cavity mold with after-feeding reservoir of claim 4, wherein: the diameter of the heat-preservation hole (14) is set to be 8mm, and the depth is set to be 15 mm.

6. A large-bore piston obtained by casting using the single-cavity mold with a feeding head according to any one of claims 1 to 5; the method is characterized in that: including piston body (21), water material (22) and rising head material (23), piston body (21), water material (22) and rising head material (23) connect gradually, water material (22) and be the level setting, rising head material (23) are the slope setting, and keep away from the level that waters material (22) one end and be higher than with the level of watering material (22) one end of being connected.