CN1006860B - Forging process - Google Patents

Abstract

The present invention relates to a technology for precisely forging tooth embedded coupling. The component part used for driving is provided with a short tooth ring with a concave root and a tooth shape, the radial inner sides of the teeth are abutted on a public cylindrical surface, and the tooth root is positioned on a public base surface. The method comprises the following procedures: (a) preliminarily forging; (b) precisely pressing at a cold state. According to the procedures, firstly, the teeth are processed into parallel tooth sides and are precisely pressed finally in order to lead the tooth side engaging surface to form accurately.

Description

Forging process

The present invention is a kind of forging of making tooth embedding coupling piece.This part that is used for gear shift has the short gear ring of the recessed tooth of band root, and the radially inner face of these teeth leans against on the common circle cylinder, and its tooth root is positioned on the public bottom surface.Add man-hour, at first tooth is made parallel flank, and then carried out final pressure-sizing.

In Deutsche Bundespatent specification of exhibition DEAL3134857, this method that has the kinematic coupling of double wedge or recess of existing manufacturing.According to the introduction of this specification, double wedge just is being shaped in the forging process substantially, and its top surface along the common edge that intersects with two mating surfaces, leaves allowance at least.Pressure-sizing stroke subsequently makes mating surface obtain required gradient.During pressure-sizing, can double wedge support and the forging die surface of its mating surface quadrature between.

Also has a kind of known method (seeing Deutsche Bundespatent specification of exhibition German Auslegeschrift No. 2040413) in addition, be used for making mesiodens embedding wheel with recessed rooted tooth, this method is made the tooth with parallel flank by rough forge, the tooth jumping-up, make it to form roof domatic shape then.In this example, adopted a kind of special-purpose tilting gearing, the drift that can move radially is reached in the interdental space, thereby obtain required flank tilted shape.Because material deformation at the tooth root place radially, tooth root has just been slackened.This is the major defect of this method.

(referring to DE3134857) known forging method that these are mentioned at first is restricted when being used for making transmission uses short teeth embedding coupling piece, and inconvenience is used when required precision height and tooth embedding coupling piece are very little at least.The flank that constitutes mating surface is free forming by the excess stock at jumping-up top, and therefore, the form accuracy of mating surface just can not be according to people

Will and improve.

In view of the above problems, purpose of the present invention is exactly to make these known processing methods can be applied to the manufacture process of above-mentioned tooth embedding coupling piece without restriction, thereby improves the forming accuracy of mating surface.

Purpose of the present invention realizes by following process steps, that is: work step (a) " the preliminary forging ", and work step (b), " cold conditions pressure-sizing ", these two work steps constitute the characteristic of claim 1.Work step (a) can be cold forging or forge hot, also can be other forging and pressing commercial run with effect same.

Work step (b) is an one or many pressure-sizing stroke, and it can be divided into three phases.Just on the one hand, show the fundamental difference of the present invention and aforementioned prior art at this.

In its phase I (aa), at first the head to the tooth that leaves surplus in the tooth depth direction carries out just upsetting.In this process, the straight flank outside of belly, that is, only produce the variation that is difficult for discovering with respect to the total face of cylinder of each tooth flank that extends of plane radially.Material is compressed, and in the second stage (bb) of subsequently pressure-sizing, this compression makes tooth by the cold conditions compacting, particularly in the tooth root zone of being supported by bottom surface.This cold conditions compacting at tooth root position is not only very important to the form accuracy of root fillet part, its special role also is, in the stage (cc) subsequently, promptly the last rammer of profile of tooth is hit in the operation, the gradient of tooth flank surface also is subjected to its accurate control, and the promptly actual mating surface of tooth flank surface.According to the height of tooth, the conditions such as recessed and form accuracy of tooth flank surface, can suitably adopt forging die support teeth side surface.In the phase III of forming process, also be accomplished simultaneously as the roof slope shape of the tooth top portion of short tooth characteristics, make tooth flank surface obtain final gradient whereby.

In principle, within a pressure-sizing stroke, finish, may accomplish as described three shaping stages of feature b in the claim 1.But, with twice pressure-sizing stroke, once finish shaping stage (aa) and (bb), finish last shaping stage (cc) again,

So more favourable.

Experience shows that by the tooth embedding coupling piece that such process makes, its short gear ring can satisfy all requirements of transmission in the automobile construction.

In enforcement of the present invention, the very important point is, in the manufacture process, tooth top on the semi-finished product should exceed the last plane as the upper bound, the face of cylinder, at least a part of excess stock of its tooth top should stretch out from this plane, and, in last jumping-up operation, the tooth top that is shaped should flush with this plane, or is lower than this plane.

In upsetting process, the distortion of tooth top should be controlled at such degree, makes that the tooth that is shaped on the semi-finished product is cut off from the face of cylinder when final upsetting process finishes, and cuts off the position between the tooth top and last plane of setting tooth.Not hard to imagine, the material that is cut is towards the distortion of the space between tooth and the tooth, thus the gradient of formation tooth flank surface; The common face of cylinder of each tooth does not hinder each shaping of teeth process again, and can separate at facewidth the best part and each tooth both for each tooth provides effective support.

With reference to the accompanying drawings, introduce the manufacture process of tooth embedding coupling piece.

Fig. 1 has represented half of the axial cutaway view of tooth embedding coupling piece.

Fig. 2 is the side isometric view of a tooth embedding coupling piece part, and has represented each shaping stage of tooth;

Three different phase schematic diagrames that Fig. 3 is shaped for tooth.

The tooth embedding coupling piece 1 of band centre bore 2 shown in Figure 1 is selected from multiple possible form, and as beating among the figure shown in the hatched section part, having between upper plane 4 and lower flat 5, two planes on the torus 3 is the face of cylinder 6.The face of cylinder 6 is mutually attached therewith for each tooth 7 on the short gear ring.This weak point gear ring is made up of four toxoplasms 8 along the circumference uniform distribution of tooth embedding coupling piece 1, and five teeth are arranged on each toxoplasm 8.

Figure 2 shows that the part of such toxoplasm 8, a Manufactured tooth is arranged on it

7, the tooth of two the expression process intermediatenesses of also having drawn in addition.The tooth that indicates (aa) mark in right side is the semi-finished product profile of tooth of making through the forge hot operation.The tooth flank surface 9a of this tooth extends along the sagittal plane with respect to toxoplasm 8, its tooth top 10 be shaped as the roof domatic, and slightly exceed the upper face 4 of toxoplasm 8.The tooth 7c who indicates mark (cc) in left side is the profile of tooth of having made, but its tooth flank surface 9c, that is the gradient of its mating surface has very big exaggeration when drawing.The tooth depth of this tooth is shorter significantly than the tooth in (aa) stage on right side; This is the result of twice jumping-up, once is the intermediate shape of upsetting into (bb) Fig. 3 from the rough forge shape of (aa), the final profile of tooth (cc) of then upsetting out for the second time.Said latter two shape (bb) and (cc) preferably obtain by twice continuous pressure-sizing stroke.As can be seen from Fig. 2, tooth top tip and the plane 4 of the tooth 7c after finishing are substantially flush.But, this geometrical relationship is not the characteristics of essence.In the tooth embedding coupling piece of other form, tooth top both can exceed upper plane 4 slightly, also can be more lower slightly than this plane.

Profile of tooth in the middle of on Fig. 2 repeatedly is drawn in two teeth together, and that wherein solid line is represented is completed tooth 7b, and what dotted line was represented is the forge next semi-finished product profile of tooth identical with right side (aa) tooth.This middle profile of tooth signal be used for representing formalizing deformation extent of tooth this process from initial forging and pressing operation to final pressure-sizing.This degree of deformation can also be more clearly visible from Fig. 3.Cylindrical surface 6 shows orthographic projection on the plane at Fig. 3, represents with two dotted lines up and down.In this figure, for the deflection of the profile of tooth (aa) that is shaped from blocking to the profile of tooth (bb) of preliminary pressure-sizing, and from (bb) again to the deflection of the tooth (cc) of final pressure-sizing shaping, also all draw turgidly, to show its degree.Latter two above-mentioned procedure of processing is finished in the pressure-sizing process by pressure-sizing stroke once or twice.In preliminary upsetting process, that is at shaping stage (bb), the most basic any is that the peripheral region 11 of the corner 12 of tooth root portion obtains the cold conditions compacting.This cold conditions compaction is to tooth flank surface

The setting of 9c has the influence of essence.When the last pressure-sizing of tooth 7c was shaped, its side surface 9c, that is the mating surface of tooth formed accurate surface, and extend downwards to give fixed angle, to widen tooth top portion.

In the pressure-sizing process of shaping stage (bb),, just might when tentatively jumping-up is to state (bb) from state (aa) tooth, make fillet part 12 earlier in tooth root portion by the known forging die (not shown) of a cover.Make tooth flank surface 9b imperceptible gradient promptly occur like this at shaping stage (bb).Just in the final upsetting formation stage (cc), tooth flank surface 9b just obtains the gradient of expecting.On Fig. 3, the contrast between the shaping stage (cc) on shaping stage in left side (aa) and right side has been expressed and has been added hatched share zone 13 on the cylindrical surface 6.Shifting appears in this regional material, and the result widens the back tooth top that is shaped.Profile of tooth shown in Fig. 2 and Fig. 3 mainly is schematic.In fact, the edge of tooth, state (aa) and (bb) especially mediates

The edge, be slightly curved, and, finally shaped profile of tooth (cc), the gradient of its tooth flank surface is obviously much smaller.After the first road pressure-sizing step (shaping stage bb) is finished, tooth flank surface may by the part of tooth top slightly to evagination, by under part then omit recessedly inwards, become shape shown in dotted lines in Figure 3.

Claims (8)

1, the precision forging technology of manufacture component tooth embedding coupling piece (1), this part that is used for the transmission gearshift has the short gear ring of the recessed tooth of band root, and the radially inner face of tooth is positioned on the common circle cylinder, and its tooth root then places on the bottom surface; During manufacturing, at first these teeth are processed parallel tooth flank surface, then it is carried out last jumping-up; The feature of the procedure of processing of this technology exists

A) make semi-finished product by first step forging, the size of the tooth (7) on the short tooth of semi-finished product leaves surplus, and is higher than the tooth top (10) of the tooth of finishing at last;

B) semi-finished product to cold conditions carry out the processing of one or many subsequent fine, and its mode is:

Aa) at first tooth top portion (10) is tentatively upset and hit, the radial outside surface of the tooth when hitting of upsetting is supported by the side wall surface of forging die;

Bb) when preliminary rammer is hit, or utilize further fine finishining, tooth flank surface (9b) forms rounding to bottom surface (5), makes the root area (11,12) of tooth (7) be subjected to the cold conditions compacting;

Cc) in last upsetting process, make tooth top portion obtain the shape on slope, roof, make tooth flank surface obtain recessed with it corresponding gradient simultaneously.

2, the method for claim 1, it is characterized in that, last plane (4) as cylindrical surface (6) upper bound is suitable substantially with the overhead height of tooth, semi-finished product tooth top portion has at least the unnecessary material of a part to protrude on this on plane, and hit in the process in final rammer, the tooth top of the tooth (7) of last typing was flushed with going up plane (4), or a little less than this plane.

3, method as claimed in claim 2, it is characterized in that, in tooth top portion is upset the process of hitting, hit constantly final the rammer, cut off from periphery (6) at the tooth that stage and semi-finished product forms, its position (13) are positioned between the tooth top and last plane (4) of last setting.