CN113798421A

CN113798421A - Engine rocker arm forming process

Info

Publication number: CN113798421A
Application number: CN202111078159.1A
Authority: CN
Inventors: 沈运海; 黎明; 蒲焕章; 汤桥平
Original assignee: Hunan Goz Precision Machinery Co ltd
Current assignee: Hunan Goz Precision Machinery Co ltd
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2021-12-17

Abstract

The invention provides an engine rocker arm forming process, which comprises the following steps: 1) blanking, namely, blanking by adopting a bar shears; 2) heating; 3) forging and forming, namely putting the heated blank into a forming die for processing and forming; the forming die comprises an upper die and a lower die which are matched with each other, the corresponding surface between the upper die and the lower die is a die surface, the upper die is provided with two upper die cavities, the lower die is provided with two lower die cavities, the two upper die cavities and the two lower die cavities are symmetrically arranged to form two die cavities, the shapes of the die cavities are the same as the external shapes of the rocker arms, the shapes of the two die cavities are inverted with each other, the small heads of the two die cavities are adjacent and are in a reverse buckling shape, the peripheries of the die cavities are provided with flash grooves, and the flash grooves are only provided with flash bridge parts; 4) trimming the forged piece; 5) heat treatment; 6) shot blasting; 7) and finishing, namely, placing the shot-blasted product into a finishing die for leveling. Above-mentioned technical scheme can improve the production efficiency of rocking arm forging greatly.

Description

Engine rocker arm forming process

Technical Field

The invention relates to the technical field of forging, in particular to a forming process of an engine rocker arm.

Background

The rocker arm is a very important part on the engine and is used for driving the valve to open and close. The rocker arm is shaped like an obtuse triangle, and has a large head and a small head, and the middle part of the rocker arm is protruded downwards and is provided with a shaft hole for mounting a rocker arm shaft. In order to ensure the machining precision and the manufacturing cost of the rocker arm, a forging process is generally adopted to manufacture a rocker arm blank.

The traditional forming process flow of the rocker arm comprises the following steps: blanking, heating, flattening the whole piece, bending the blank, forging and forming, trimming, heat treating, shot blasting and finishing, the process flow is complex, and the whole shape of the rocker arm forging piece is irregular, so that the heated bar stock needs to be flattened and the blank needs to be bent before forging and forming, the operation is inconvenient, the working time is long, and the production efficiency is low. Moreover, the blank bending usually adopts free forging, and the distribution and placement of the blanks are difficult to achieve uniformity, so that the cavity filling during forging forming is unstable, and the rejection rate is high.

Disclosure of Invention

The invention aims to provide an engine rocker arm forming process capable of improving production efficiency.

In order to solve the technical problems, the technical scheme of the invention is as follows: a forming process of an engine rocker arm, wherein the rocker arm is provided with a large head part and a small head part, the middle part of the rocker arm protrudes downwards and is provided with a shaft hole for mounting a rocker arm shaft, and the forming process of the rocker arm comprises the following steps: 1) blanking, namely, blanking by adopting a bar shears; 2) heating; 3) forging and forming, namely putting the heated blank into a forming die for processing and forming; the forming die comprises an upper die and a lower die which are matched with each other, the corresponding surface between the upper die and the lower die is a die surface, the upper die is provided with two upper die cavities, the lower die is provided with two lower die cavities, the two upper die cavities and the two lower die cavities are symmetrically arranged to form two die cavities, the shapes of the die cavities are the same as the external shapes of the rocker arms, the shapes of the two die cavities are inverted with each other, the small heads of the two die cavities are adjacent and are in a reverse buckling shape, the peripheries of the die cavities are provided with flash grooves, and the flash grooves are only provided with flash bridge parts; 4) trimming the forged piece; 5) heat treatment; 6) shot blasting; 7) and finishing, namely, placing the shot-blasted product into a finishing die for leveling.

Preferably, the flash bridge of the molding die is provided only around the two lower cavities.

Wherein, the heating of the step 2) is to put the bar stock into a heating furnace to be directly heated to 1200 +/-10 ℃.

Wherein, the trimming of the forged piece in the step 4) is to perform trimming on the rocker arm forged piece by adopting a 165T punch press, and the trimming temperature is 850 +/-10 ℃.

The specification of the adopted bar stock during blanking in the step 1) is ∅ 28mm, and the shearing length is 145 mm.

Furthermore, the die surface of the upper die and the die surface of the lower die are rectangles with the same size, four corners of the die surface of the upper die are provided with limiting blocks protruding downwards, and four corners of the die surface of the lower die are provided with limiting grooves corresponding to the limiting blocks.

The beneficial effects obtained by the invention are as follows: the invention mainly improves the forming die, changes the traditional single-die cavity into double-die cavity, and the two die cavities are inverted, the small heads of the two die cavities are adjacent and are in reverse buckling shape, and the flash bridge part is arranged around the die cavities, thus the two die cavities in obtuse triangle are spliced into a parallelogram, so that the material feeding distribution of the bar is more uniform when the bar is forged and formed, thereby the two processing steps of flattening the whole material and bending the blank can be omitted, the process flow is simplified while the quality is ensured, and the production efficiency is improved. And because this kind of mould can once only forge out two rocking arm forgings, consequently further improve production efficiency one time again.

Drawings

FIG. 1 is a schematic structural view of a molding die according to an embodiment of the present invention;

FIG. 2 is a bottom view of the upper mold of FIG. 1;

FIG. 3 is a top view of the lower mold of FIG. 1;

the reference signs are:

10-upper die 11-upper die cavity

20-lower die 21-lower die cavity 22-flash bridge portion.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. In the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, mechanically or electrically connected, or interconnected between two elements, directly or indirectly through intervening media, and the specific meaning of the terms may be understood by those skilled in the art according to their specific situation.

The preferred embodiment of the invention is: a forming process of an engine rocker arm, wherein the rocker arm is provided with a large head part and a small head part, the middle part of the rocker arm protrudes downwards and is provided with a shaft hole for mounting a rocker arm shaft, and the forming process of the rocker arm comprises the following steps:

1) blanking, namely blanking by adopting a bar stock cutter, wherein the specification of a bar stock is ∅ 28mm, and the shearing length is 145 mm;

2) heating, namely putting the bar stock into a heating furnace to be directly heated to 1200 +/-10 ℃;

3) forging and forming, namely putting the heated blank into a forming die for processing and forming; as shown in fig. 1 to 3, the forming mold includes an upper mold 10 and a lower mold 20 which are matched with each other, a corresponding surface between the upper mold 10 and the lower mold 20 is a mold surface, the upper mold 10 is provided with two upper mold cavities 11, the lower mold 20 is provided with two lower mold cavities 21, the two upper mold cavities 11 and the two lower mold cavities 21 are symmetrically arranged to form two mold cavities, the shape of the mold cavity is the same as the external shape of the rocker arm, the two mold cavities are inverted, the small heads of the two mold cavities are adjacent and are in a reverse buckling shape, a flash groove is arranged around the mold cavity, and the flash groove only has a flash bridge portion 22; preferably, the flash bridge 22 is provided only around the two lower cavities 21; the die surface of the upper die 10 and the die surface of the lower die 20 are rectangles with the same size, limiting blocks 12 protruding downwards are arranged at four corners of the die surface of the upper die 10, and limiting grooves 23 corresponding to the limiting blocks 12 are arranged at four corners of the die surface of the lower die 20;

4) trimming the forged piece, namely trimming the forged piece of the rocker arm by adopting a 165T punch, wherein the trimming temperature is 850 +/-10 ℃;

5) heat treatment;

6) shot blasting;

7) and finishing, namely, placing the shot-blasted product into a finishing die for leveling.

The embodiment has the advantages that the forming die is improved in the important point, the traditional single-die cavity is changed into the double-die cavity, the shapes of the two die cavities are inverted, the small heads of the two die cavities are adjacent and are in a reverse buckling shape, and the flash bridge parts are arranged around the die cavities, so that the two die cavities which are in obtuse triangles are spliced into a parallelogram, the material conveying distribution of the bar is uniform when the bar is formed by forging, the two processing steps of flattening the whole bar and bending the blank can be omitted, the process flow is simplified while the quality is ensured, and the production efficiency is improved. And because this kind of mould can once only forge out two rocking arm forgings, consequently further improve production efficiency one time again.

The above embodiments are preferred implementations of the present invention, and the present invention can be implemented in other ways without departing from the spirit of the present invention.

Some of the drawings and descriptions of the present invention have been simplified to facilitate the understanding of the improvements over the prior art by those skilled in the art, and some other elements have been omitted from this document for the sake of clarity, and it should be appreciated by those skilled in the art that such omitted elements may also constitute the subject matter of the present invention.

Claims

1. A forming process of an engine rocker arm, wherein the rocker arm is provided with a large head part and a small head part, the middle part of the rocker arm protrudes downwards and is provided with a shaft hole for mounting a rocker arm shaft, and the forming process of the rocker arm is characterized by comprising the following steps:

1) blanking, namely, blanking by adopting a bar shears;

2) heating;

3) forging and forming, namely putting the heated blank into a forming die for processing and forming; the forming die comprises an upper die (10) and a lower die (20) which are matched with each other, the corresponding surface between the upper die (10) and the lower die (20) is a die surface, the upper die (10) is provided with two upper die cavities (11), the lower die (20) is provided with two lower die cavities (21), the two upper die cavities (11) and the two lower die cavities (21) are symmetrically arranged to form two die cavities, the shapes of the die cavities are the same as the external shape of the rocker arm, the shapes of the two die cavities are inverted, the small heads of the two die cavities are adjacent and are in a reverse buckling shape, flash grooves are arranged around the die cavities, and the flash grooves only have flash bridge parts (22);

4) trimming the forged piece;

5) heat treatment;

6) shot blasting;

2. The process of forming an engine rocker arm of claim 1, wherein: the flash bridge part (22) of the molding die is only arranged around the two lower die cavities (21).

3. The process of forming an engine rocker arm according to claim 1 or 2, wherein: the heating of the step 2) is to put the bar stock into a heating furnace to be directly heated to 1200 +/-10 ℃.

4. The process of forming an engine rocker arm according to claim 1 or 2, wherein: and 3) trimming the forged piece in the step 4), namely trimming the rocker arm forged piece by adopting a 165T punch, wherein the trimming temperature is 850 +/-10 ℃.

5. The process of forming an engine rocker arm according to claim 1 or 2, wherein: the specification of the adopted bar stock during blanking in the step 1) is ∅ 28mm, and the shearing length is 145 mm.

6. The process of forming an engine rocker arm according to claim 1 or 2, wherein: the mould surface of going up mould (10) and the mould surface of lower mould (20) are the same rectangle of size, the mould surface four corners of going up mould (10) is equipped with convex stopper (12) downwards, the mould surface four corners of lower mould (20) be equipped with stopper (12) corresponding spacing groove (23).