CN109590422B

CN109590422B - Closed near-net forming process and die for drum type steering knuckle finish forging

Info

Publication number: CN109590422B
Application number: CN201910120263.9A
Authority: CN
Inventors: 张运军; 曹世金; 张宏涛; 余国林; 胡洪斌; 朱荣宇; 左培; 左长兵; 夏巨谌
Original assignee: Hubei Tri Ring Forging Co Ltd
Current assignee: Hubei Tri Ring Forging Co Ltd
Priority date: 2019-02-18
Filing date: 2019-02-18
Publication date: 2021-02-26
Anticipated expiration: 2039-02-18
Also published as: CN109590422A

Abstract

The invention provides a closed near-net forming process and a die for a drum type steering knuckle finish forging, aiming at the drum type steering knuckle forging with a fork lug and a rod part axis forming a certain deflection angle, a drum type steering knuckle pre-forging piece obtained by closed extrusion near-net forming is placed into a vertically separable closed final forging near-net forming die, and a forming force and a die closing force are applied through an upper die to form the drum type steering knuckle forging piece. The invention also provides a die for realizing the method, the working part comprises a male die, a separable combined female die and a combined female die closing and opening mechanism, the separable female die is closed to form a female die cavity by utilizing the horizontal oil cylinder and the T-shaped guide rail, forming force is applied by utilizing the male die, and meanwhile, vertical pressure applied by die forging equipment is converted into horizontal pressure by utilizing the cone cylinder structure to provide die closing force. According to the invention, through the closed net forming process and the vertical separable female die structure, the near net forming of the drum type steering knuckle final forging piece can be realized, and the forging piece can be smoothly taken out.

Description

Closed near-net forming process and die for drum type steering knuckle finish forging

Technical Field

The invention belongs to a processing method of a steering knuckle forging, and particularly relates to a closed near-net forming process and a closed near-net forming die of a drum type steering knuckle finish forging.

Background

For a drum type steering knuckle forge piece (figure 1) with fork lugs and a rod part axis forming a certain deflection angle, the current common forging process comprises three steps of blank making, horizontal pre-forging and horizontal finish forging. Luyan (forging die design manual (2 nd edition), mechanical industry press 2006.) introduces a horizontal open finish forging process based on three-step blank making and horizontal open pre-forging on a hot die forging press, and the outstanding problem of the traditional die forging process is that the flash metal loss is as high as 27% -28%. Zhang Gan et al (research and development and application of automobile steering knuckle small-fin precision forging technology, 2018,43(8):1-7.) reported a steering knuckle similar to a drum-type steering knuckle, and open-type small-fin finish forging is carried out after open-type small-fin pre-forging, so that the metal loss of fins is not increased on the basis of pre-forging and is still 12% -13%. In order to further improve the material utilization rate, the Lihuan and the like (influence of the forging mode of the automobile steering knuckle on the processing manufacturability, hot processing, 2013, (7):50-52.) realize vertical closed pre-forging and closed finish forging by supplementing materials on the inner sides of the two fork ears, but the supplemented materials still need to be cut and removed subsequently.

Disclosure of Invention

The invention provides a closed near-net forming process and a die for a drum type steering knuckle finish forging, which can realize near-net forming of the steering knuckle finish forging with a fork lug and a rod part axis forming an alpha inclination angle on a conventional precision forging hydraulic press. The method is characterized in that:

(1) a closed near-net forming process of a drum type knuckle final forging piece is characterized in that a drum type knuckle pre-forging piece obtained by closed vertical extrusion near-net forming is placed into a female die of a closed type final forging near-net forming die, acting force is applied through a male die to form the drum type knuckle pre-forging piece into the drum type knuckle forging piece, only small machining allowance is reserved on the part, matched with other parts, of the forging piece, and the rest parts of the forging piece meet the requirements of the drum type knuckle parts.

(2) The pre-forging part for realizing the closed near-net forming process of the drum type steering knuckle finish forging part is designed to be of a plane fork-shaped structure, and the shape and the size of a rod part are the same as those of the finish forging part; the flange is designed into a rectangular structure which is tangent to the horizontal projection shapes of the two fork lugs and has an increased thickness; the cross section shapes of the two fork lugs are the same as the cross section shape of the lower section of the fork lug of the final forging, the side length is a vertical tetrahedron with the side length of the final forging reduced by 1mm and four edges and corners r2, the height of the vertical tetrahedron is determined according to the corresponding equal volume, the two straight fork lugs are parallel to the vertical direction along the height direction, the axis of the rod part inclines rightwards, and the oblique angle of the straight fork lugs is alpha.

(3) The die (figure 2) for realizing the closed near-net forming process of the drum type steering knuckle finish forging comprises a die frame, a male die, a separable combined female die and a combined female die closing and opening mechanism. The die carrier is composed of a lower template 1, an upper template 8, a guide pillar 2, a pressing ring 3 and a guide sleeve 7, the guide pillar 2 is in transition fit with the lower template 1 and is fastened with the lower template 1 through the pressing ring 3 by a screw, and the guide sleeve 7 is in transition fit with the upper template 8 and is fastened into a whole by the screw; the male die 9 is fixed below the upper die plate 8; the separable combined female die consists of a left half female die 6 and a right half female die 11, the left half female die 6 is connected with the lower template 1 into a whole through a screw, and the right half female die 11 is matched with a corresponding T-shaped groove on the lower template 1 through a T-shaped guide rail at the bottom of the right half female die 11; the combined female die closing and opening mechanism comprises a conical cylinder 5, four inner hexagonal socket head cap screws 4, four nitrogen springs 10 and a connecting rod 12, wherein the conical cylinder 5 is connected with an upper die plate 8 through the four uniformly distributed inner hexagonal socket head cap screws 4, the four uniformly distributed nitrogen springs 10 are arranged in holes corresponding to the conical cylinder 5 and the upper die plate 8, the length of the inner hexagonal socket head cap screws 4 and the compression stroke of the nitrogen springs 10 are determined according to the working stroke of a male die 9, the left end of the connecting rod 12 is connected with a right half female die 11 through threads, and the right end of the connecting rod is connected with a horizontal oil cylinder piston rod of die forging equipment. The lower template 1 and the upper template 8 of the die are respectively arranged above the workbench of the precision forging hydraulic press and below the outer slide block.

Furthermore, the die forging equipment is a precision forging hydraulic press with a horizontal oil cylinder arranged on the right side of the workbench.

Furthermore, the edges of the flange cavity of the left half female die and the right

half female die

6 and 11 are designed into a step structure, the upper section of the step extends outwards for 6-8 mm in parallel along the straight arm of the flange cavity, and when the finish forging forming is finished, a parallel shunting depressurization cavity is formed along the outer edge of the flange.

(4) The working process of the die is as follows: firstly, placing a steering knuckle pre-forging piece into a fixed left half female die 6 through a manual or robot clamp and keeping the steering knuckle pre-forging piece still; secondly, operating a horizontal oil cylinder on the right side of the precision forging hydraulic machine to enable a piston rod to move leftwards, pushing the right half female die 11 to move leftwards through the connecting rod 12, closing the right half female die 6 and pressing a preforging piece tightly, and then loosening and withdrawing the clamp; thirdly, operating a slide block of the precision forging hydraulic press to drive a male die 9 and a conical cylinder 5 to move downwards, firstly, compressing two half

female dies

6 and 11 by the conical cylinder 5 through a nitrogen spring 10, then, applying acting force to the pre-forging piece by the downward movement of the male die 9 to enable a left fork lug and a right fork lug of the pre-forging piece to generate compression deformation and upset to form a front half cylinder and a rear half cylinder at the upper section of the fork lug of the final forging piece, and simultaneously, enabling forked bottom metal of the pre-forging piece to be converted from a compression state into radial flow to form a left flange and a right flange so as to form the required drum-type steering; fourthly, after the die forging is finished, operating a slide block of the precision forging hydraulic press to drive the male die 9 and the conical cylinder 5 to return upwards to the initial position; and fifthly, operating the right horizontal oil cylinder to move rightwards to move the right half female die 11 along the T-shaped groove on the lower template 1 to separate the two half female dies, and then taking out the final forged piece, wherein one working cycle is ended.

The finish forging process is to form a drum type steering knuckle forge piece meeting the drawing requirements in a closed separable female die by using a preforging piece, and the material utilization rate of the drum type steering knuckle forge piece can reach more than 99%. Meanwhile, according to the structural characteristics that the drum type knuckle forging piece is symmetrical left and right along the vertical plane where the fork lug middle plane is located, the female die is designed into a vertical separable structure which is symmetrical left and right, a closed die forging special device is formed by adopting an opening and closing mechanism, the closed finish forging near-net forming batch production of the drum type knuckle with a complex structure and the knuckle with a similar structure can be realized, an ejection device is not required to be arranged on a die, the structure is simplified, and the operation time of die forging production can be shortened. Compared with the existing die forging process and equipment production, the material saving and efficiency improvement are obvious. In addition, the design of the flow dividing and pressure reducing cavity is not only beneficial to the smooth flowing of the metal in the middle of the flange into the edge of the flange cavity, but also can reduce the die forging forming force and adjust the change of the blank volume.

Drawings

FIG. 1 is a diagram of a drum knuckle finish forging.

FIG. 2 is a schematic view of a closed near-net-shape forming die for a drum type knuckle finish forging.

Labeled in fig. 2: the device comprises a lower template 1, a guide pillar 2, a pressing ring 3, an inner hexagonal socket head cap screw 4, a conical barrel 5, a left half female die 6, a guide sleeve 7, an upper template 8, a male die 9, a nitrogen spring 10, a right half female die 11 and a connecting rod 12.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments.

A90 type automobile steering knuckle with large market demand at home and abroad in recent years is selected as an application example of the novel process and the mold. In order to adapt to closed type finish forging near-net forming, the head of the pre-forging piece is designed into a plane fork-shaped structure, the cross section of each fork lug is determined according to the shape and the size of the cross section of the lower section of each fork lug of the forging piece, the cross section is rectangular, the length of each fork lug is 87mm, the width of each fork lug is 58mm, the height of each fork lug is determined according to the volume of the corresponding fork lug on a drawing (figure 1) of the finish forging piece, the height of a larger fork lug is 135mm, and the height of a; the horizontal projection shape of the flange is the same as the rectangular shape of the horizontal projection of the two-fork ear envelope body on the forging drawing, the length is 226.7mm, the width is 87mm, and the height is 35mm according to the volume of the flange part of the finish forging; the shank shape is the same as the size and finish forge.

FIG. 2 shows a schematic structural diagram of a finish forging die of the invention, which comprises a die carrier, a male die, a separable combined female die and a combined female die closing and opening mechanism. The die carrier is composed of a lower template 1, an upper template 8, a guide pillar 2, a pressing ring 3 and a guide sleeve 7, the guide pillar 2 is in transition fit with the lower template 1 and is fastened with the lower template 1 through the pressing ring 3 by a screw, and the guide sleeve 7 is in transition fit with the upper template 8 and is fastened into a whole by the screw; the male die 9 is fixed below the upper die plate 8; the separable combined female die consists of a left half female die 6 and a right half female die 11, the left half female die 6 is connected with the lower template 1 into a whole through a screw, and the right half female die 11 is matched with a corresponding T-shaped groove on the lower template 1 through a T-shaped guide rail at the bottom of the right half female die 11; the combined female die closing and opening mechanism comprises a conical cylinder 5, four inner hexagonal socket head cap screws 4, four nitrogen springs 10 and a connecting rod 12, wherein the conical cylinder 5 is connected with an upper die plate 8 through the four uniformly distributed inner hexagonal socket head cap screws 4, the four uniformly distributed nitrogen springs 10 are arranged in holes corresponding to the conical cylinder 5 and the upper die plate 8, the length of the inner hexagonal socket head cap screws 4 and the compression stroke of the nitrogen springs 10 are determined according to the working stroke of a male die 9, the left end of the connecting rod 12 is connected with a right half female die 11 through threads, and the right end of the connecting rod is connected with a horizontal oil cylinder piston rod of die forging equipment. The lower template 1 and the upper template 8 of the die are respectively arranged above the workbench of the precision forging hydraulic press and below the outer slide block.

The die forging equipment is a precision forging hydraulic press YK34J-2500 with a horizontal oil cylinder arranged on the right side of a workbench, and the maximum thrust of the horizontal oil cylinder is 50 tons.

The edges of the flange cavity of the left half female die 6 and the right half female die 11 are designed into a step structure, the upper section of the step extends outwards for 6mm along the straight arm of the flange cavity in parallel, and when the finish forging forming is finished, a parallel shunting pressure reduction cavity is formed along the outer edge of the flange.

The process of closed near-net forming of the drum type steering knuckle finish forging by using the die comprises the following steps: firstly, placing a steering knuckle pre-forging piece into a fixed left half female die 6 through a manual or robot clamp and keeping the steering knuckle pre-forging piece still; secondly, operating a horizontal oil cylinder on the right side of the precision forging hydraulic machine to enable a piston rod to move leftwards, pushing the right half female die 11 to move leftwards through the connecting rod 12, closing the right half female die 6 and pressing a preforging piece tightly, and then loosening and withdrawing the clamp; thirdly, operating a slide block of the precision forging hydraulic press to drive a male die 9 and a conical cylinder 5 to move downwards, firstly, compressing two half female dies 6 and 11 by the conical cylinder 5 through a nitrogen spring 10, then, applying acting force to the pre-forging piece by the downward movement of the male die 9 to enable a left fork lug and a right fork lug of the pre-forging piece to generate compression deformation and upset to form a front half cylinder and a rear half cylinder at the upper section of the fork lug of the final forging piece, and simultaneously, enabling forked bottom metal of the pre-forging piece to be converted from a compression state into radial flow to form a left flange and a right flange so as to form the required drum-type steering; fourthly, after the die forging is finished, operating a slide block of the precision forging hydraulic press to drive the male die 9 and the conical cylinder 5 to return upwards to the initial position; and fifthly, operating the right horizontal oil cylinder to move rightwards to move the right half female die 11 along the T-shaped groove on the lower template 1 to separate the two half female dies, and then taking out the final forged piece, wherein one working cycle is ended.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a nearly net forming die of closed of drum-type knuckle finish forging which characterized in that: the die carrier is composed of a lower template (1), an upper template (8), a guide pillar (2), a pressing ring (3) and a guide sleeve (7), wherein the guide pillar (2) is in transition fit with the lower template (1) and is fastened with the lower template (1) through the pressing ring (3) by screws, and the guide sleeve (7) is in transition fit with the upper template (8) and is fastened into a whole by screws; the male die (9) is fixed below the upper template (8); the separable combined female die consists of a left half female die (6) and a right half female die (11), the left half female die (6) is connected with the lower template (1) into a whole through a screw, and the right half female die (11) is matched with a corresponding T-shaped groove on the lower template (1) through a T-shaped guide rail at the bottom of the right half female die; the combined female die closing and opening mechanism consists of a conical cylinder (5), four inner hexagonal cylindrical head screws (4), four nitrogen springs (10) and a connecting rod (12), wherein the conical cylinder (5) is connected with an upper die plate (8) through the four uniformly distributed inner hexagonal cylindrical head screws (4), the four uniformly distributed nitrogen springs (10) are arranged in holes corresponding to the conical cylinder (5) and the upper die plate (8), the length of the inner hexagonal cylindrical head screws (4) and the compression stroke of the nitrogen springs (10) are determined according to the working stroke of a male die (9), the left end of the connecting rod (12) is connected with a right half female die (11) through threads, the right end of the connecting rod is connected with a horizontal oil cylinder piston rod of die forging equipment, a lower die plate (1) and an upper die plate (8) of a die are respectively arranged above a workbench of the die forging equipment and below an outer sliding block, the edge of a flange die cavity is designed into a step structure, the upper section of the step extends outwards in parallel along a straight arm of, when the finish forging forming is finished, a parallel shunting decompression cavity is formed along the outer edge of the flange; the forming principle is that a drum type steering knuckle pre-forging piece obtained by closed extrusion near-net forming is placed into a female die of a closed type finish forging near-net forming die, acting force is applied through a male die, so that the drum type steering knuckle pre-forging piece is formed into the drum type steering knuckle forging piece, only a small machining allowance is left on the part, matched with other parts, of the forging piece, the rest parts of the forging piece meet the requirements of the drum type steering knuckle parts, the pre-forging piece is designed to be of a plane fork-shaped structure, and the shape and the size of a rod part of the pre-forging piece are; the flange is designed into a rectangular structure which is tangent to the horizontal projection shapes of the two fork lugs and has an increased thickness; the cross section shapes of the two fork lugs are the same as the cross section shape of the lower section of the fork lug of the final forging, the side length is a vertical tetrahedron with the side length of the final forging reduced by 1mm and four edges and corners r2, the height of the vertical tetrahedron is determined according to the corresponding equal volume, the two straight fork lugs are parallel to the vertical direction along the height direction, the axis of the rod part inclines rightwards, and the oblique angle of the straight fork lugs is alpha.

2. The closed near-net forming die for the drum type knuckle final forging piece as claimed in claim 1, wherein: the right side of the workbench of the precision forging hydraulic press is provided with a horizontal oil cylinder.

3. The closed near-net forming die for the drum type knuckle final forging piece as claimed in claim 1, wherein: the working process comprises the first step of placing a steering knuckle pre-forging piece into a fixed left half female die (6) through a manual or robot clamp and keeping the steering knuckle pre-forging piece still; secondly, operating a horizontal oil cylinder on the right side of the precision forging hydraulic machine to enable a piston rod to move leftwards, pushing a right half female die (11) to move leftwards through a connecting rod (12), closing the right half female die with a left half female die (6) and pressing a pre-forged part tightly, and releasing and withdrawing a clamp at the moment; thirdly, operating a slide block of the precision forging hydraulic press to drive a male die (9) and a conical cylinder (5) to move downwards, firstly, compressing the two half female dies by the conical cylinder (5) through a nitrogen spring (10), then, applying acting force to the pre-forging piece by the downward movement of the male die (9), enabling left and right fork lugs of the pre-forging piece to generate compression deformation and upsetting to form front and rear half cylinders at the upper section of the fork lug of the final forging piece, and simultaneously, enabling forked bottom metal of the pre-forging piece to be converted from a compression state into radial flow to form left and right flanges so as to form the required drum-type steering knuckle final forging piece; fourthly, after the die forging is finished, operating a slide block of the precision forging hydraulic press to drive the male die (9) and the conical cylinder (5) to return upwards to the initial position; and fifthly, operating the right horizontal oil cylinder to move rightwards to move the right half female die (11) along the T-shaped groove on the lower template (1) to separate the two half female dies, and then taking out the final forged piece, wherein one working cycle is ended.