CN102615221B - Radial and axial rolling forming method for large-sized double-groove ring piece - Google Patents

Abstract

The invention relates to a radial and axial rolling forming method of a large double-groove ring. The radial and axial rolling forming method of large double-groove rings mainly includes the following realization steps: (1) Billet making: uniformly heating the bar section from room temperature to the hot forging deformation temperature, and then passing the hot section on a press Upsetting, punching, punching and continuous skin to make ring blanks for rolling. The size of the ring blanks is determined according to the ring size, rolling ratio, and the ratio of radial and axial feeds; (2) Rolling pass Design: The rolling pass is composed of the working surface of the driving roll and the working surface of the core roll. The dimensions of the working surface of the driving roll and the core roll are determined according to the rolling line speed, equipment parameters, rolling deformation conditions, ring blank size and ring size; (3) Roll forming: put the prepared ring blank on the ring rolling machine for rolling, and the rolling process is divided into three stages: pre-rolling, main rolling, and shaping rolling. The feed speed and feed amount are reasonably distributed Control is carried out, and when the outer diameter of the measured ring reaches a predetermined value, the rolling process ends. The invention has the characteristics of high production efficiency, low production cost and good product quality.

Description

A radial and axial rolling forming method of a large double-groove ring

technical field

The invention relates to a radial and axial rolling forming method of a large double-groove ring. the

Background technique

A large double-groove ring with a diameter of more than 1 meter and symmetrical grooves on the inner surface is widely used as a slewing support ring, a large bearing ring, etc. in construction machinery, port machinery, and wind power generation equipment. Such rings have harsh working conditions and are subjected to low temperature, heavy load, high impact, etc. for a long time, and have high requirements on their performance and service life. Diameter and axial rolling of rings (shown in Figure 1) is an advanced plastic processing technology for producing large rings. It can obtain high-quality large rings with high geometric accuracy and good structural properties in a short period of time through continuous local plastic deformation. pieces. However, the radial and axial rolling process of rings is a complex deformation process under the coupling of multiple process parameters, and the design and process control of rolling process parameters are difficult, especially for rings with special-shaped cross-sections. Unreasonable, when the diameter of the ring reaches the size requirement, the cross-sectional profile cannot be filled, and even the rolling process is unstable, forming rolling defects, and the rate of scrap and defective products is high. Therefore, at present, most large rings with special-shaped cross-sections are rolled into rectangular cross-section rings through radial and axial rolling, and then cut to form the cross-section profile, such as the above-mentioned large double-groove rings. Grooves are processed by mechanical cutting, which consumes a lot of cutting material and processing time. It is difficult to maintain the same machining accuracy of the two grooves. Moreover, the cutting process destroys the metal flow distribution of the ring and reduces the mechanical properties of the ring, resulting in low production efficiency. , the cost is high, and the quality and life are difficult to guarantee. the

Contents of the invention

In view of the above-mentioned deficiencies, the object of the present invention is to provide a radial and axial rolling forming method of a large-scale double-groove cross-section ring. By rationally designing the rolling process parameters and optimizing the rolling process, the direct Rolling is formed into a double-groove ring, which significantly reduces the consumption of groove cutting materials and man-hours, and can obtain better metal streamline distribution, improve production efficiency and product quality, and reduce production costs. the

In order to achieve the above purpose, the technical solution of the present invention is: a large-scale double-groove cross-section ring (hereinafter referred to as the ring) radial and axial rolling forming method, including the following realization steps:

(1) Billet making: uniformly heat the bar section from room temperature to the hot forging deformation temperature, and then the hot section is subjected to upsetting, punching, punching and skinning on a press to make a ring blank for rolling. The size of the ring blank is determined according to the following steps

1) Calculate the ring volume and cross-sectional area

ring volume Calculate according to the formula

in, is the ring width; , are the inner and outer radii of the ring, respectively; is the ring groove radius; is the central angle of the groove section.

Ring cross-sectional area Calculate according to the formula

,in is the ring wall thickness.

2) Determine the rolling ratio

Rolling ratio is the cross-sectional area of the ring blank cross-sectional area of the ring The ratio, which reflects the degree of rolling deformation of the ring blank, the greater the rolling ratio, the greater the deformation of the ring blank. If the rolling ratio is too small, the ring blank cannot be fully deformed to obtain a fine and evenly distributed grain structure; if the rolling ratio is too large, the ring blank is prone to internal damage, cracks and other structural defects due to excessive deformation. For large double-groove ring diameter axial rolling, The value is generally taken as 2.5-4.

3) Determine the ratio of radial and axial feeds

During the rolling process of the ring blank, its radial wall thickness and axial height decrease at the same time, and the reasonable distribution of radial and axial deformation is very important for the stability of the rolling process and the geometric accuracy of the formed ring. For radial and axial rolling of large double-groove rings, the ratio of radial and axial feeds It can be determined as follows:

in, , are the total radial and axial feeds of ring rolling, respectively, , is the wall thickness and height of the ring blank.

4) Determine the wall thickness and height of the ring blank

According to the rolling ratio , Ratio of radial and axial feed , the wall thickness of the ring blank can be determined and height for

,

5) Determine the inner and outer radius of the ring blank

According to blank wall thickness ,high and ring volume , combined with the principle of plastic deformation volume invariance, the outer radius of the ring blank can be determined , inner radius for

,

(2) Rolling pass design: The rolling pass is composed of the working surface of the driving roller and the working surface of the core roller. Among them, the working surface of the driving roller is a cylindrical surface, and the working surface of the core roller is composed of a cylindrical surface and two grooved spherical surfaces. The structure of the driving roller and the core roller is shown in Figure 4. The dimensions of the working surface of the driving roll and the core roll are determined as follows:

1) Determine the radius and width of the working surface of the driving roller

In order to ensure stable rolling forming of the ring, the linear speed of the driving roll Usually take 1.1 ~ 1.3m/s, according to the linear speed of the driving roller The radius of the working surface of the drive roller can be determined ,in, is the driving roller speed, is the motor speed, is the transmission ratio, , Determined by device parameters. Driving roller face width

2) Determine the size of the core roller groove ball

The core roller groove ball is used to form the groove of the ring, and its size corresponds to the size of the groove of the ring, which can be determined as follows

, , ,

in, , are the ring groove depth and width, respectively, , , , Respectively, the depth, height, radius and center angle of the section center of the groove ball of the core roll.

3) Determine the spherical radius and width of the core roller groove

In order to ensure that the ring blank produces continuous rolling deformation in the radial pass, the radius of the working surface of the driving roll and the radius of the spherical surface of the core roll groove should meet the following conditions.

In the formula, is the spherical radius of the core roll groove; is the friction angle, is the coefficient of friction. In order to enable the core roll to smoothly penetrate the inner hole of the ring blank for rolling, the maximum working surface radius of the core roll should generally be guaranteed . According to the above conditions, it can be determined that the value range of the spherical radius of the core roller groove is

Therefore, the radius of the cylindrical surface of the core roller can be determined as . According to the geometric relationship, the axial width of each section of the core roller can be determined as

, ,

(3) Rolling and forming: put the prepared ring blank on the ring rolling machine for rolling, and the rolling process is controlled in three stages: pre-rolling, main rolling, and shaping rolling. In the pre-rolling stage, the core roll and the upper tapered roll are controlled to feed slowly along the radial and axial directions, gradually eliminating the wall thickness difference and height difference caused by forging billets; in the main rolling stage, the equipment capacity is fully utilized to control the core The roller and the upper tapered roller are fed at a relatively fast speed in the radial direction and axial direction respectively, so that the ring is fully deformed; in the shaping and rolling stage, when the outer diameter of the ring is 100-200mm from the predetermined value, the core roller and the upper tapered roller are controlled. Feed at a slow speed in the radial direction and axial direction respectively, eliminate the wall thickness difference and ellipticity caused by ring deformation, keep the ring growing slowly, and stop radially and axially when the outer diameter of the measured ring reaches a predetermined value Feed, the rolling process ends. During the rolling process, the control curves of feed speed and feed amount at each stage are shown in Figure 5, and the parameters in the figure are determined as follows:

Radial feed rate: , ,

Radial feed: , , ,

Axial feed rate: , ,

Axial feed: , , ,

in,

The minimum feed rate required to cause rolling deformation of the ring, .

The present invention adopts ring diameter and axial rolling process to process large-scale double-groove rings, and realizes direct rolling and forming of rectangular ring blanks into double grooves by designing ring blanks and rolling passes and controlling the rolling process. The ring piece reduces the consumption of materials and processing hours, improves the metal flow distribution of the ring piece, improves the production efficiency and product quality, and reduces the production cost. the

Description of drawings

Fig. 1 is the principle diagram of axial rolling of the diameter of the ring part of the embodiment of the present invention;

1-driving roller, 2-core roller, 3-guiding roller, 4-ring blank, 5-upper cone roller, 6-lower cone roller, 7-measurement roller;

Fig. 2 is a ring sectional view of an embodiment of the present invention;

Fig. 3 is a sectional view of a ring blank according to an embodiment of the present invention;

Fig. 4 is a structural diagram of the working surface of the driving roller in the embodiment of the present invention;

Fig. 5 is a structural diagram of the working surface of the core roll of the embodiment of the present invention;

Fig. 6 is a control curve diagram of radial feed amount and radial feed speed in ring rolling according to an embodiment of the present invention;

In the figure, ① pre-rolling stage, ② main rolling stage, ③ shaping rolling stage;

Fig. 7 is a control curve diagram of axial feed amount and axial feed speed of ring rolling according to an embodiment of the present invention;

In the figure, ① pre-rolling stage, ② main rolling stage, ③ shaping rolling stage.

Detailed ways

Taking the large double-groove ring (referred to as the ring) as shown in Figure 2 as the specific implementation object, the geometric dimensions of the ring are: outer radius 1050mm, inner radius 944, width 178mm, 40.25mm, 18.5mm, groove central angle for , groove arc radius 20mm, groove depth 17mm, groove width It is 39.5mm. The radial and axial rolling forming method is realized in the following steps:

1) Billet making: evenly heat the bar section from room temperature to the hot forging deformation temperature, then upsetting, punching, and punching the hot section on a press to make a ring blank 4 for rolling. According to the 4 size design method of the ring blank, take the rolling ratio is 3.5, determine the size of the ring blank 4 as: outer radius 409.51mm, inner radius 162.87mm, width It is 251.63mm. (shown in Figure 3).

2) Rolling pass design: Take the rolling line speed is 1.2m/s, according to the rolling pass design method, the rolling pass is designed according to the structure shown in Figure 4, where: the radius of the driving roller 1 working surface 350mm, width 178mm; core roller 2 groove ball depth 17mm, groove ball width 39.5mm, center angle of groove ball for , ball radius 20mm, core roller 2 groove spherical radius 150mm, cylindrical surface radius 133mm, core roll 2 width 178mm, 113.88mm, 18.5mm, It is 40.25mm.

3) Roll forming: put the ring blank 4 made according to the above dimensions on the ring rolling machine for rolling, and the rolling process is controlled in three stages: pre-rolling, main rolling, and shaping rolling. The radial and axial feed speed and feed rate at each stage of the rolling process are controlled according to the curve shown in Figure 6, where: the pre-rolling stage, the radial and axial feed speed , Respectively 0.65mm/s, 0.38mm/s, radial and axial feed , 6.18mm, 3.68mm respectively; main rolling stage, radial and axial feed speed , Respectively 3.78mm/s, 2.24mm/s, radial and axial feed , 105.09mm and 62.59mm, respectively; during the shaping and rolling stage, the radial and axial feed rates , Respectively 0.54mm/s, 0.32mm/s, radial and axial feed , They are 12.36mm and 7.36mm respectively. When the outer diameter of the ring measured by the measuring roller 7 reaches a predetermined value, the radial and axial feeds are stopped, and the rolling process ends.

Claims (1)

1. A radial and axial rolling forming method for a large inner double-groove ring piece comprises the following implementation steps:

(1) blank preparation: uniformly heating the bar material section from room temperature to a hot forging deformation temperature, then upsetting, punching and punching the hot material section on a press machine to prepare a ring blank for rolling, wherein the size of the ring blank is determined according to the following steps

1) Calculating the volume and cross-sectional area of the ring

The ring volume is determined by

Wherein,is the ring width;、the inner radius and the outer radius of the ring piece are respectively;is the ring groove radius;is a groove section central angle;

cross sectional area of ringDetermined by the following formula

WhereinThe wall thickness of the ring part;

2) determination of the Rolling ratio

Rolling ratioIs the sectional area of ring blankAnd ring cross-sectional areaRatio of rolling to rollingThe value is 2.5-4;

3) determining a ratio of radial to axial feed

Ratio of radial to axial feedDetermined as follows:

wherein,、respectively radial and axial total feed of ring rolling,、the wall thickness and the height of the ring blank,the depth of the ring groove is taken as the depth of the ring groove;

4) determining wall thickness and height of ring blank

According to rolling ratioRadial and axial feed ratioDetermining the wall thickness of the ring blankAnd heightIs composed of

，

5) Determining the inner and outer radii of the ring blank

According to the wall thickness of the blankHeight, heightAnd ring volumeDetermining the outer radius of the ring blank by combining the principle of unchanged volume of plastic deformationInner radius ofIs composed of

，

(2) Designing a rolling pass: the rolling pass consists of a driving roller working surface and a core roller working surface, the driving roller working surface is a cylindrical surface, the core roller working surface is formed by combining the cylindrical surface and two groove spherical surfaces, and the sizes of the driving roller working surface and the core roller working surface are determined according to the following steps:

1) determining drive roller face radius and width

Linear velocity of drive rollerTaking 1.1-1.3 m/s, and driving the roller according to the linear velocityDetermining drive roller face radiusWhereinin order to drive the rotational speed of the roller,the number of revolutions of the motor is,for gear ratio, motor speedTransmission ratio ofDrive roll face width determined by machine parameters

2) Determining core roller groove ball size

The core roller groove ball is used for forming the ring groove, the size of the core roller groove ball corresponds to that of the ring groove, and the size is determined according to the following formula

，，，

Wherein,、respectively the depth and the width of the groove of the ring piece,、、、the depth, height, radius and section central angle of the core roller groove ball are respectively;

3) determining core roller groove spherical radius and width

The radius of the working surface of the driving roller and the spherical radius of the core roller groove satisfy the following formula

In the formula,the radius of the spherical surface of the core roller groove;in order to be the angle of friction,the maximum working surface radius of the core roller is satisfied by the friction coefficientDetermining the value range of the spherical surface radius of the core roller groove according to the conditions as

Thereby determining the radius of the cylindrical surface of the core roll to beDetermining the axial width of each section of the working surface of the core roller as

，，

Wherein, B_1aIs the axial distance from the groove on the ring to the upper end face of the ring, B_1bThe axial distance between the upper groove and the lower groove of the ring piece is defined;

(3) rolling and forming: putting the prepared ring blank on a ring rolling machine for rolling, wherein the rolling process is controlled according to three stages of pre-rolling, main rolling and shaping rolling; in the pre-rolling stage, the core roller and the upper conical roller are controlled to be respectivelyRadial and axial feed, pre-rolling radial feed ratePre-rolling radial feedPre-rolling axial feed ratePre-rolling axial feedGradually eliminating the wall thickness difference and the height difference generated by forging blank making; in the main rolling stage, the core roller and the upper conical roller are controlled to respectively feed along the radial direction and the axial direction, and the radial feeding speed of the main rollingRadial feed of main rollingMain rolling axial feed speedAxial feed of main rollingFully deforming the ring piece; in the shaping rolling stage, when the outer diameter distance of the ring piece is 100-200 mm, controlling the core roller and the upper conical roller to respectively feed along the radial direction and the axial direction, and controlling the radial feeding speed of the shaping rollingRadial feed of shaping rollingAxial feed rate of shaping rollingAxial feed of shaping rollingEliminating wall thickness difference and ovality generated by ring deformation, keeping the ring to grow slowly, stopping feeding in the radial direction and the axial direction when the outer diameter of the ring measured by the measuring roller reaches a preset value, finishing the rolling process,

whereinThe minimum feed speed required to produce the rolling deformation of the ring,。