CN202639181U

CN202639181U - Cold forging die

Info

Publication number: CN202639181U
Application number: CN 201220271485
Authority: CN
Inventors: 龚卫红; 黄容; 朱亚萍; 季成
Original assignee: YANCHENG LIYAN PRECISION FORGING CO Ltd
Current assignee: Jiangsu Liken Technology Co ltd
Priority date: 2012-06-08
Filing date: 2012-06-08
Publication date: 2013-01-02
Anticipated expiration: 2022-06-08

Abstract

The utility model provides a cold forging die which comprises an upper punch, a lower punch and a lower die. A forging stock is placed in a die cavity of the lower die and subjected to cold extruding through the upper punch and the lower punch to form central holes in the centers of two ends of a spline-shaft forging piece, and the forging stock is obtained through inverted extrusion to a large end of a blank. The cold forging die is used for performing cold extruding on the forging stock which is forged through warm forging inverted extrusion processes and does not have the central holes so as to obtain the central holes at two ends of the spline-shaft forging piece, and accordingly, the size accuracy of the central holes is guaranteed.

Description

A kind of cold forging die

[technical field]

The utility model relates to metal precision forging field, particularly a kind of cold forging die.

[background technology]

Please refer to shown in Figure 1, it is a kind of spline shaft forged piece, the center of the upper/lower terminal of this forging is provided with centre bore 110, these two positioning center holes that centre bore is the follow-up machined spline of this forging, therefore, very high to herein centre bore positioning requirements, especially the coherence request to center axially bored line and interior axially bored line is very high.With the centre bore that general forging method obtains, the central hole size precision is low, and the spline shaft forged piece cylindrical is based on the low precision of beating of centre bore, and axially bored line and centre bore axis uniformity are poor in the described forging.At present, the forging process of processing spline shaft forged piece centre bore adopts cold extrusion to forge more, namely in the large end of backward extrusion, extrude centre bore, can guarantee that like this cylindrical is based on the precision of beating of centre bore, but, owing to can not guarantee that centre bore is full of abundance after backward extrusion puts in place, therefore can't guarantee whether the central hole size precision reaches requirement.

Therefore, be necessary to propose a kind of improved technical scheme and solve the problems referred to above.

[utility model content]

The purpose of this utility model is to provide a kind of cold forging die, and the central hole size precision of the spline shaft forged piece that it can forge is higher.

To achieve these goals, the utility model proposes a kind of cold forging die, it comprises upper punch, low punch and counterdie, forging stock is put into the die cavity of described counterdie, by described upper punch and low punch described forging stock is carried out cold extrusion, form centre bore with the center at the spline shaft forged piece two ends, described forging stock is to carry out backward extrusion by the large end to blank to obtain.

Further, described mould arranges upper punch and guiding by mould orifice location.

Further, be provided with outgassing groove on the described upper punch, it is used for discharging the air of die cavity.Described outgassing groove is a plurality of, is shaped as semicircle, is uniformly distributed on the cylindrical of upper punch.

Further, in the beginning extrusion process, when upper punch enters counterdie 10-15mm, touch forging stock and begin extruding.

Compared with prior art, the cold forging die in the utility model is used for that warm forging backward extrusion operation is forged the forging stock that does not have centre bore and carries out cold extrusion, obtains centre bore with the two ends at spline shaft forged piece, thereby guarantees the central hole size precision.

[description of drawings]

In order to be illustrated more clearly in the technical scheme of the utility model embodiment, the accompanying drawing of required use was done to introduce simply during the below will describe embodiment, apparently, accompanying drawing in the following describes only is embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.Wherein:

Fig. 1 is a kind of generalized section of spline shaft forged piece;

Fig. 2 is the forging method process chart in one embodiment of spline shaft forged piece centre bore;

Fig. 3 carries out the shaping schematic diagram of cold extrusion centre bore step for the cold forging die in use the utility model;

Fig. 4 is the forging method shape of product change procedure figure in one embodiment of spline shaft forged piece centre bore; With

Fig. 5 is the enlarged diagram of the B indication part among Fig. 4.

[specific embodiment]

For above-mentioned purpose of the present utility model, feature and advantage can be become apparent more, below in conjunction with the drawings and specific embodiments the utility model is described in further detail.

Alleged " embodiment " or " embodiment " refer to be contained in special characteristic, structure or the characteristic at least one implementation of the utility model herein.Different local in this manual " in one embodiment " that occur not are all to refer to same embodiment, neither be independent or the embodiment mutually exclusive with other embodiment optionally.

Cold forging die in the utility model is used for that warm forging backward extrusion operation is forged the forging stock that does not have centre bore and carries out cold extrusion, obtains centre bore with the two ends at spline shaft forged piece, thereby guarantees the central hole size precision.

Please refer to shown in Figure 2ly, it is the forging method process chart in one embodiment of spline shaft forged piece centre bore.Described technological process comprises the steps.

Step 210, blanking.

Select suitable bar, adjust cutting length, with Weight control in predefined scope.

Step 220, base.

Described base is in order to remove the defectives such as hot rolled rod outer surface oxide skin, micro-crack, rusty stain, to improve surface quality.

Step 230, forward extrusion.

Described forward extrusion is conventional forward extrusion, in the present embodiment, and by blank is carried out the exterior contour that forward extrusion begins to take shape the splined shaft product.

Step 240, jumping-up.

Jumping-up refers to the blank height be reduced and the operation of diameter (or lateral dimension) increase with pressure.

Step 250, the warm forging backward extrusion.

Thereby described warm forging backward extrusion refers to by to the anti-forging stock that obtains not having centre bore that squeezes of the large end of blank.Because adopt the warm forging backward extrusion, therefore, its required forging force is little, mould structure is simple, and die life is long.

Step 260, the cold extrusion centre bore.

Forging stock is put into mould carry out cold extrusion, form centre bore with the center at the spline shaft forged piece two ends, in the cold extrusion centre bore, can reach the effect of finishing inner chamber.

In a preferred embodiment, between preforming and forward extrusion operation, also include ball blast, Tu layer heating process, between backward extrusion operation and cold extrusion centre bore operation, also comprise temperature control cooling, ball blast and phosphorus saponifying process.

In sum, the forging method of described spline shaft forged piece centre bore at first adopts warm forging backward extrusion operation to obtain not having the forging stock of centre bore, then forging stock is carried out cold extrusion and obtain centre bore with the two ends at spline shaft forged piece, adopt like this mode of temperature, cold forging combination, can effectively improve the central hole size precision.

Please refer to shown in Figure 3ly, it is for using cold forging die in the utility model to carry out the shaping schematic diagram of cold extrusion centre bore step.Wherein 410 is that upper punch, 420 is that low punch, 430 is that counterdie, 440 is forging stock.Mould is the guiding by mould orifice mould.Described mould comprises upper punch 410, low punch 420 and counterdie 430.In order to guarantee the large and small end outer circles of centre bore and spline shaft forged piece, described mould arranges upper punch and guiding by mould orifice location.In the beginning extrusion process, when upper punch enters the long L of counterdie (as shown in Figure 3, general L is about 10-15mm), touch forging stock and begin extruding, because the precision of die orifice size in the Mould Machining process of counterdie 430 is high, therefore, utilizes guiding by mould orifice can guarantee guiding accuracy, thereby the effect that reaches accurate guiding guarantees axiality, can effectively guarantee circle product external beating based on endoporus simultaneously.

After upper punch enters lower mode cavity, because the guiding by mould orifice gap is little, continue descendingly, the air in the die cavity can't be discharged and must be produced larger resistance, be unfavorable for forging, therefore, in the present embodiment, be provided with a plurality of outgassing grooves 412 on the upper punch, allow Bas Discharged, to reduce the descending resistance of upper punch, these outgassing grooves 412 are distributed in does not affect guiding accuracy on the drift, and is convenient to processing.In a preferred embodiment, described outgassing groove 412 is three, is shaped as semicircle, is uniformly distributed on the cylindrical of upper punch 410.

Please refer to shown in Figure 4ly, it is the utility model shape of product change procedure figure in one embodiment.Wherein Fig. 4 (a) is the shape of product schematic diagram behind the blanking procedure, Fig. 4 (b) is the shape of product schematic diagram (being the shape schematic diagram of blank) after the preforming, Fig. 4 (c) is the shape of product schematic diagram after the forward extrusion, Fig. 4 (d) is the shape of product schematic diagram after the jumping-up operation, Fig. 4 (e) is the shape of product schematic diagram (being forging stock shape schematic diagram) after the warm forging backward extrusion operation, and Fig. 4 (f) is the product schematic diagram after the cold extrusion centre bore operation.

Please refer to shown in Figure 5ly, it is the enlarged diagram of the B indication part among Fig. 4.

Cold forging die in the utility model is used for that warm forging backward extrusion operation is forged the forging stock that does not have centre bore and carries out cold extrusion, obtain centre bore with the two ends at spline shaft forged piece, thereby guarantee the central hole size precision, adopt the guiding by mould orifice mould, high accuracy guiding when guaranteeing cold extrusion, guarantee that not only cylindrical based on the precision and guaranteed the uniformity of centre bore axis and interior axially bored line of beating of endoporus, realizes finishing to this part simultaneously, guaranteed the required precision of product cavity size.

Above-mentioned explanation has fully disclosed the specific embodiment of the present utility model.It is pointed out that and be familiar with the scope that any change that the person skilled in art does the specific embodiment of the present utility model does not all break away from claims of the present utility model.Correspondingly, the scope of claim of the present utility model also is not limited only to previous embodiment.

Claims

1. cold forging die, it is characterized in that, it comprises upper punch, low punch and counterdie, forging stock is put into the die cavity of described counterdie, by described upper punch and low punch described forging stock is carried out cold extrusion, form centre bore with the center at the spline shaft forged piece two ends, described forging stock is to carry out backward extrusion by the large end to blank to obtain.

2. mould according to claim 1 is characterized in that, described mould arranges upper punch and guiding by mould orifice location.

3. mould according to claim 2 is characterized in that, is provided with outgassing groove on the described upper punch, and it is used for discharging the air of die cavity.

4. mould according to claim 3 is characterized in that, described outgassing groove is a plurality of, is shaped as semicircle, is uniformly distributed on the cylindrical of upper punch.

5. mould according to claim 2 is characterized in that, in the beginning extrusion process, when upper punch enters counterdie 10-15mm, touches forging stock and begins extruding.