CN1037672A - The cross wedge rolling of eccentric stepped shaft - Google Patents

Abstract

The technology of production eccentric stepped shaft of the present invention is to adopt the insert die of special shape, and the multidiameter of non-eccentricity is become eccentric stepped shaft for needs.All is a circle of cross wedge rolling machine running in finish to eccentric shaft this two deformation stages again by blank to concentric shafts.Produce the eccentric stepped shaft forging stock with this technology generations for die forging, can simplify production process greatly, improve stock utilization and labor productivity.The eccentric stepped shaft forging stock of producing does not have burr, and productivity ratio is high 3～5 times than die forging.

Description

The cross wedge rolling of eccentric stepped shaft

The invention belongs to the stress metal processing industry.

Eccentric stepped shaft class part is widely used on the engineering goods such as automobile, tractor, lathe.Traditional manufacture method is to use die-forging forming, cuts edge then, and shaping needs three process to finish the forging stock manufacturing operation altogether, and operation is many, and stock utilization is low.

Purpose of the present invention is exactly in order to solve existing shortcoming of producing eccentric stepped shaft technology, to provide a kind of production process simple, the cross wedge rolling of the production eccentric shaft that stock utilization and productivity ratio are high.

The method of the production eccentric stepped shaft forging stock that the present invention proposes is earlier the forging stock that heats to be rolled into concentric multidiameter on cross wedge rolling machine, rerolls into eccentric stepped shaft afterwards.Ladder distortion with one heart, the distortion of eccentric ladder, cut-out etc. all are to finish in a circle of milling train running, eccentric ladder distortion is to realize by the iron chains piece mould that is installed on the cross wedge rolling machine, and, die needed and the eccentric ladder of ladder distortion is die needed with one heart is that order is installed on the milling train, this method both can be used on the flat cross wedge rolling machine, also can be used on the cross wedge rolling mill roller.

Making the process of concentric multidiameter, is to rely on common cross wedge rolling to realize.The non-eccentricity part that obtains requiring on the forging stock in this stage and eccentric part are in length and diametric shape and size.When this deformation stage finished, and then the iron chains piece mould of special shape entered duty, and the ladder that will become eccentric part is under the effect of special shape mould, and distortion produces metallic radial and shifts the formation eccentric stepped shaft gradually.In the workpiece rotary course, the metallic radial transfer increases gradually along with drafts and finishes.The transition of two deformation stages should be steady, and the drafts of eccentric part should be started from scratch and be increased gradually.

The shape of the working surface bus of special iron chains piece mould, relevant with the off-centre operation diameter with the offset size, relevant with selected milling train form.When selecting flat cross wedge rolling machine for use, iron chains piece die worker makes the sine curve that surperficial bus is a standard, and its equation is:

y＝-asin (x)/(r) ……（1）

Wherein: a is offset (a≤a _Max)

R is the off-centre operation radius

When selecting the double-roller type cross wedge rolling machine for use, iron chains piece die worker makes surperficial bus equation and is:

R＝R ₀-asin (R _O)/(r) θ……（2）

Wherein: a is offset (a≤a _Max)

R is the off-centre operation radius

R ₀Mould wedge tip circle radius for without acceptance of persons the time.

R is an iron chains piece mould surface bus radius.

θ is a central angle.

Coordinate and each parameter are seen accompanying drawing 1, accompanying drawing 2.Accompanying drawing 1 is flat cross wedge rolling machine iron chains piece mould bus schematic diagram, and accompanying drawing 2 is the iron chains piece die surface bus schematic diagram of cross wedge rolling mill roller.

The limiting value a of offset _MaxCan calculate by following formula:

a _max＝r[1+ (1 + R)/(4μ ²(R + r)) (1- $\sqrt{{\mathrm{1\; +\; 8\; \mu }}^2}$ )]]……（3）

Wherein: r is the off-centre operation radius

R is roll surface wedge tip circle radius for without acceptance of persons the time

μ is the coefficient of sliding friction between mould and workpiece

Intact for guaranteeing that eccentric part is shaped, lobbing mould drafts changes two complete cycles should occur.Period 1 finishes metallic radial and shifts, and second period is used for shaping.The non-eccentricity part of eccentric part both sides keeps in touch at the second stage and the die surface that are out of shape, but drafts is zero.

Eccentric stepped shaft cross wedge rolling of the present invention compare with existing technology have technology simple, reduce production equipment, stock utilization height, the forging precision height, the productivity ratio height, advantage such as reduce production costs.

Fig. 1 is the surperficial bus schematic diagram of flat cross wedge rolling machine iron chains piece mould;

Fig. 2 is the surperficial bus schematic diagram of the iron chains piece mould of cross wedge rolling mill roller;

Fig. 3 is " liberation " CA141 axle-spare tyre lifter part drawing;

Fig. 4 is the side view of Fig. 3;

Fig. 5 is an iron chains piece die drawing;

Fig. 6 is the profile of Fig. 5;

Fig. 7 is the cutaway view of Fig. 5;

Fig. 8 is the deformation process figure of eccentric shaft;

Fig. 9 is a dual roll type cross wedge rolling sketch drawing;

Figure 10 is flat cross wedge rolling sketch;

Figure 11 is a wedge cross rolling deformation process sketch;

Figure 12 is liberation CA141 axle-spare tyre lifter cross wedge rolling die expanded view.

With the CA141 axle-spare tyre lifter in " liberation " truck is example.Offset is 3 millimeters, and the off-centre operation radius is 14 millimeters, selects the double-roller type cross wedge rolling machine, and then iron chains piece die worker makes surperficial bus equation and is:

R＝R ₀-3sin (R _O)/14 θ

Calculate eccentric limit a according to formula (3) _Max＞3, but the offset of this part can be produced with this method in the range of work.Fig. 3, Fig. 4 are part drawing.

The structure of iron chains piece mould such as Fig. 6, Fig. 7, the key of finishing the invention task is that iron chains piece mould should have correct shape and size.Iron chains piece mould is installed on the main body mould, and main body mould is installed on the cross wedge rolling machine bolster or on the roll again.

Whole forming processes of eccentric shaft as shown in Figure 8.Blank is deformed into and is desired concentric shafts in 1 district, and concentric shafts is out of shape under the effect of iron chains piece mould becomes eccentric shaft, and roll two deformation processes that circle are all finished.Except charging before being out of shape, pilot process is without any need for manually-operated.

The process that in 1 district blank deformation is become concentric multidiameter is basic wedge cross rolling deformation, and its basic principle is shown in Fig. 9,10.Fig. 9 is the double-roller type cross wedge rolling machine, and Figure 10 is flat cross wedge rolling machine.The identical mould that has wedge shaped projection of installation dimension on roll and module surface up and down, blank is placed between two modules.Mould motion drives the blank rotation, while blank rotate and be compressed and produce and extend axially, form need multidiameter.The cross section of blank and product all is round.Shown in Figure 11 is the citation form and the flow of metal process of mould.In the I section, along with the mould motion, voussoir is pressed into metal depth to be increased gradually, is the wedging section; The II section is the broadening degree for the certain width of compression distance increases process; III is a plastic section; IV is a cutting-off process, is segregation section.The eccentric part distortion is to increase a pair of lobbing iron chains piece between III section and IV section, makes the concentric shafts distortion become eccentric shaft.

Iron chains piece die worker do surperficial bus by formula (1) or (2) on wire cutting machine tool, process.The die main body material is ZG55, iron chains piece mold materials is 5CrMnMo, with this iron chains piece mould is successfully shut out axle one spare tyre lifter, and quality reaches specification requirement, compare with former technology, save steel 35%, save 0.258 kilogram, per hour produce 600 for every, boost productivity 5 times, forging key dimension precision reaches the micron order in JB3834-85 " steel forging part tolerance and the machine-finish allowance " standard, and through the macrostructure inspection, inner nothing is loose.

Claims (2)

1, a kind of cross wedge rolling of eccentric stepped shaft, blank with heating rolls into concentric multidiameter on cross wedge rolling machine earlier, it is characterized in that concentric multidiameter distortion, eccentric stepped shaft distortion, cut off to be in a circle of milling train running, to finish, multidiameter deformation stage and the die needed order of eccentric stepped shaft deformation stage are installed on the cross wedge rolling machine with one heart, and the distortion of eccentric stepped shaft realizes by the iron chains piece mould that is installed on the cross wedge rolling machine.

2, the cross wedge rolling of eccentric stepped shaft according to claim 1 is characterized in that iron chains piece mould iron chains on the parent mould on the milling train, iron chains piece mold work surface, and the bus equation of its working surface is when selecting flat cross wedge rolling machine for use:

y＝-asin (x)/(r) ;

Equation is when selecting the double-roller type cross wedge rolling machine for use:

R＝R _o-asin (R _O)/(r) θ

The limiting value formula of offset is:

a _max＝r[1+ (1 + R)/(4μ ²(R + r)) (1- $\sqrt{{\mathrm{1\; +\; 8\; \mu }}^2}$ )]。

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