CN217370258U - Forming die for paired cold rolling of eccentric groove bearing rings - Google Patents

Abstract

The utility model discloses a cold rolling forming die for a pair of offset groove bearing rings, which comprises a rolling wheel and a rolling mandrel, wherein the rolling wheel is positioned above the rolling mandrel, and the lower part of the rolling wheel is provided with a cavity for fixing a forge piece; the rolling mandrel below the cavity is provided with a rolling groove with corresponding positions, two annular protrusions for rolling path forming are arranged in the rolling groove, the two annular protrusions are symmetrically arranged along the center of the cavity, and the R parts at the highest points of the two annular protrusions are close to each other and are not on the width middle surface of the annular protrusions. The utility model has the advantages that: the utility model discloses according to the structural feature of side ditch bearing ring, creatively designs to cold process of rolling and corresponding disjunctor forging cold-rolling mould, guarantees cold fashioned stability of rolling and product size's stability, realizes raceway position preforming, reaches the effect of best festival material and best streamline, satisfies the life-span and the reliability requirement that the finished product bearing constantly improved.

Description

Forming die for paired cold rolling of eccentric groove bearing rings

Technical Field

The utility model discloses technical field, concretely relates to inclined to one side ditch ball bearing ring is cold to be rolled forming die in pairs is made to the bearing.

Background

Deep Groove Ball Bearings (Deep Groove Ball Bearings) are simple in structure, convenient to use and most widely applied. The deep groove ball bearing is mainly used for bearing radial load and can bear certain axial load, and when the radial play is large, the deep groove ball bearing has the property of an angular contact ball bearing. Compared with other types of bearings with the same size, the deep groove ball bearing has the characteristics of small friction coefficient, high limit rotating speed, high manufacturing precision, easiness in realizing bearing sealing and the like, and is a preferred bearing type for users.

Usually, the design of deep groove ball bearing ring raceways is symmetrical, the manufacturing process of a bearing ring blank mainly comprises hot forging blank making, steel pipe cutting blank making, or hot forging combined cold rolling and steel pipe cutting combined cold rolling blank making, and the service life of a ring usually adopting cold rolling is good. However, the deep groove ball bearing for the automobile gearbox is limited by the compact structure of the gearbox, and the eccentric groove design is adopted in order to match the structure and the comprehensive performance of the gearbox. The traditional ball bearing processing technology for the gearbox is mainly high-speed forging blank and cold rolling forming, and the ferrule obtained by the technology is compact in structure, good in metal streamline and good in product service life and reliability. However, this process is generally used for products with symmetrical channels, and the raceway can be preformed, but the raceway is difficult to preform due to asymmetry of the product with grooves, which results in much poorer flow lines and adversely affects the service life.

Disclosure of Invention

An object of the utility model is to provide a raceway shaping is stable, product quality is high inclined to one side ditch bearing ring is to cold forming die that rolls in pairs to the not enough of prior art.

The utility model discloses a technical scheme do: a pair of cold rolling forming dies for eccentric groove bearing rings comprises a rolling wheel and a rolling mandrel, wherein the rolling wheel is positioned above the rolling mandrel, and the lower part of the rolling wheel is provided with a cavity for fixing a forge piece; the rolling mandrel below the cavity is provided with a rolling groove with corresponding positions, two annular protrusions for rolling path forming are arranged in the rolling groove, the two annular protrusions are symmetrically arranged along the center of the cavity, and the R parts at the highest points of the two annular protrusions are close to each other and are not on the width middle surface of the annular protrusions.

According to the scheme, the flanges on two sides of the cavity of the ring rolling wheel are wider than the height of the forging piece by 0.2-0.3 mm.

According to the scheme, the R parts of the two annular bulges are arranged closely adjacent to each other and are close to the center of the rolling groove.

The utility model discloses following beneficial effect has:

1. the utility model discloses structural feature according to the bearing ring of side ditch, creatively designs to cold process of rolling and corresponding disjunctor forging cold-rolling mould, can design two shapes and the cyclic annular arch of lasso raceway ditch adaptation with the dabber of rolling, atress symmetry when the in-process disjunctor forging of cold rolling extrudees with the wheel of rolling, can guarantee cold rolling fashioned stability and product size's stability, realize raceway position preforming, reach the effect of best festival material and best streamline, satisfy the life-span and the reliability requirement that the finished product bearing constantly improves.

2. The highest point R of the two annular bulges of the cold rolling mandrel is close to the center, so that the cold rolling stress of the connected forge piece is uniform, and the forming is stable.

3. The two pieces are cold rolled in pairs, so that the rolling way part can be preformed smoothly, the metal streamline is optimized, and the long service life and the reliability of a finished product can be ensured; compared with single piece forming, the material is greatly saved, two pieces are forged at one time, and only one waste core is arranged.

Drawings

Fig. 1 is a schematic structural view of an eccentric groove bearing ring.

Fig. 2 is a schematic structural view of the cold rolling forming die of the present invention.

Fig. 3 is a schematic illustration of the dimensioning of a single cold rolled blank.

FIG. 4 is a schematic diagram of the dimension design of the conjoined forging after cold rolling forming.

FIG. 5 is a schematic diagram of the conjoined forge piece in four stages of blanking, upsetting, forming and punching.

Detailed Description

For a better understanding of the present invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings.

An off-groove bearing ring as shown in fig. 1, D is the outer diameter of the ring, D is the inner diameter of the ring, H is the height of the ring, RW is the distance of the center line of the raceway from the top surface of the ring, the center of the raceway is not on the lateral centerline of the ring, and RW is not equal to one-half of H.

Consider that the product is the partial ditch shape, in order to reach the even and purpose of optimizing the metal streamline of cold rolling shaping atress symmetry, the utility model discloses obtain the disjunctor forging with two cold rolling blank disjunctor overall arrangements, as shown in fig. 4, and the raceway ditch position of two cold rolling blanks is close to the center to the cold rolling forming die that the design corresponds.

The paired cold rolling forming die for the eccentric groove bearing ring as shown in fig. 2 comprises a rolling wheel 1 and a rolling mandrel 2, wherein the rolling wheel 1 is positioned above the rolling mandrel 2, and the lower part of the rolling wheel 1 is provided with a cavity 4 for fixing a forge piece; the rolling mandrel 2 below the cavity 4 is provided with a rolling groove with a corresponding position, two annular protrusions 3 for rolling path forming are arranged in the rolling groove, the two annular protrusions 3 are symmetrically arranged along the center of the cavity 4, and the highest points R of the two annular protrusions 3 are close to each other and are not on the width middle surface of the annular protrusions 3.

Preferably, the flanges at two sides of the cavity 4 of the ring rolling wheel 1 are wider than the height of the forging piece by 0.2-0.3 mm; the rib is also the side wall of the cavity.

In the embodiment, the cavity 4, the rolling groove and the annular protrusion 3 are designed according to a specific forging piece; the two annular bulges 3 are symmetrically arranged, and the R parts of the two annular bulges 3 are closely arranged and are close to the center of the rolling groove, so that the cold rolling stress is uniform, and the forming is stable.

In this embodiment, other designs and functions of the rolling wheel 1 and the rolling mandrel 2 are the prior art, and are not described herein again.

A cold rolling forming process for a pair of offset groove bearing rings comprises the following steps:

designing the conjoined forging after cold rolling and the size thereof.

According to a finished product diagram of the off-groove bearing ring, adding allowance outside the outline of the off-groove bearing ring finished product to obtain the size of a single cold-rolled blank; then the two cold rolling blanks are symmetrically arranged, and the groove positions (namely the centers of the rolling paths) of the two rolling paths are arranged close to the center; considering that the width of a subsequent cutting tool is usually 2mm, in order to smoothly cut off the connected forged piece, a connecting section is arranged between two cold-rolled blanks, the metal width of the connecting section is 3mm, and finally the connected forged piece is obtained; the size, the volume and the mass of the conjoined forge piece can be calculated.

Fig. 1 shows a finished view of an eccentric groove bearing ring. The size of a single cold rolled blank is shown in figure 4, the single-side outer diameter surplus is measured to be 0.5mm, the single-side inner diameter surplus is measured to be 0.6mm, the single-side height surplus is measured to be 0.7mm, and the single-side surplus of the roller path is about 1.8mm, as shown in figure 3.

Considering that the product is in a deviated groove shape, in order to achieve the purposes of symmetrical and uniform stress of cold rolling forming and metal streamline optimization, two cold rolling blanks are integrally distributed to obtain an integral forging, and the groove position of a raceway of the two cold rolling blanks is close to the center; meanwhile, in consideration of convenient cutting, a connecting section of 3mm is arranged between the two single cold rolling blanks, the size of the finally obtained connected forging is shown in figure 4 (H in figure 4 is the height of the connected forging), the allowance of the outer diameter of the connected forging is 1.0-1.2 mm, the allowance of the inner diameter is 1.0-1.2 mm, the allowance of the height is 1.2-1.5 mm, and the allowance of the raceway is 1.5-1.8 mm.

And step two, designing the size of the conjoined forging before cold rolling according to the conjoined forging after cold rolling forming.

The method is characterized in that the design of the size before and after cold rolling is carried out on the premise of determining the rolling expansion ratio, wherein the rolling expansion ratio is the inner diameter size of a forged piece after rolling expansion divided by the inner diameter size of the forged piece before rolling expansion, and the rolling expansion ratio is usually 1.2-1.5. In this example, the rolling ratio was 1.3.

The size of the connected forging after cold rolling is determined, so that the volume can be successfully calculated; according to the volume invariance principle, after the rolling ratio is determined, the inner diameter D1 of the conjoined forging before cold rolling can be determined, and then the outer diameter D1 of the conjoined forging before cold rolling can be obtained; considering the convenience of the forging piece entering the rolling wheel, the height of the conjoined forging piece before cold rolling is about 0.2mm lower than that of the conjoined forging piece after cold rolling; and finally, considering the demoulding inclination and the transition fillet based on the conventional technology, and completing the size design of the conjoined forging before cold rolling.

And step three, calculating the blanking quality and the blanking size of the conjoined forging according to the size of the conjoined forging before cold rolling. Obtaining blanking quality according to the size of the conjoined forging before cold rolling, selecting a bar material (as shown in figure 5) according to the length-diameter ratio of 0.8-1.2, and then obtaining the blanking size. The design of the step follows the characteristics of constant volume and adaptability to a high-speed upsetter.

And step four, sequentially blanking, upsetting, forming, punching and annealing to obtain the conjoined forged piece before cold rolling, as shown in FIG. 5.

In order to facilitate the material cake to enter a female die for forming, the upsetting diameter can be obtained by subtracting 1mm from the maximum outer diameter of a forged formed part, and the upsetting thickness is obtained according to a formula according to the blanking weight. According to the design size of the conjoined forge piece before cold rolling, the forming size can be designed after adding the material core according to the high-speed forging process, and the punching is designed according to the size of the forge piece, thereby belonging to the design of the simple high-speed forging process. And punching to obtain the aperture size d2 of the one-piece forging, wherein the aperture size d2 is slightly smaller than the small inner diameter size d1 and is usually smaller by 0.5-0.6 mm. Annealing belongs to conventional heat treatment of bearing steel products, and is simpler and less in order to obtain uniform spheroidized structures and reduce the hardness.

And fifthly, carrying out cold rolling treatment on the conjoined forging by using the cold rolling forming die. And (5) placing the conjoined forged piece before cold rolling obtained in the fourth step between the rolling wheel 2 and the rolling mandrel 1 of the cold rolling forming die for rolling forming to obtain the conjoined forged piece with two offset grooves.

And step six, symmetrically cutting the cold-rolled connected forged piece from the middle part to obtain two cold-rolled blanks, namely the finished product of the off-groove bearing ring.

In the above process, step four is a conventional technical means, and is not described herein. Other details of the design of the forging forming part belong to the conventional design in the upsetting process category in forging, and different forging equipment is combined to increase the core connecting sheet, the forging demoulding angle and the transition fillet; the details of the design of the rolling wheel belong to the conventional design in the design of a cold rolling die, and a cavity is basically matched with the shape of a cold rolling piece.

The forming process is suitable for a high-speed upsetter, and can produce 75-80 parts from bars to forgings in one minute after being verified by actual production.

It should be noted that the above is only a preferred embodiment of the present invention, and the present invention is not limited thereto, and although the present invention has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that the technical solutions described in the foregoing embodiments can be modified or some technical features can be replaced with equivalents, but any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (3)

1. A cold rolling forming die for a pair of offset groove bearing rings is characterized by comprising a rolling wheel and a rolling mandrel, wherein the rolling wheel is positioned above the rolling mandrel, and the lower part of the rolling wheel is provided with a cavity for fixing a forge piece; the rolling mandrel below the cavity is provided with a rolling groove with corresponding positions, two annular protrusions for rolling path forming are arranged in the rolling groove, the two annular protrusions are symmetrically arranged along the center of the cavity, and the R parts at the highest points of the two annular protrusions are close to each other and are not on the width middle surface of the annular protrusions.

2. The paired cold rolling forming die for the eccentric groove bearing ring according to claim 1, wherein flanges on two sides of a cavity of the rolling wheel are wider than the height of the forging piece by 0.2-0.3 mm.

3. The pair of rolling dies for a grooved bearing ring according to claim 1, wherein the R portions of the two annular protrusions are arranged closely adjacent to each other and are close to the center of the rolling groove.

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