CN103920795B - A kind of heat expansion vibration combined forming process of solid particle of automobile rear axle housing - Google Patents

Abstract

A thermal expansion and vibration composite forming process of solid particles of the rear axle housing of an automobile. First, the diameter is reduced to obtain a reduced diameter tube blank, and then heated to assemble a bulging mold, and then bulge to obtain a bulging tube blank. Heating again, assembling the secondary bulging mold, and secondary bulging to obtain the secondary bulging tube blank, heating three times, assembling the pressing mold, and pressing to obtain the formed part of the automobile rear axle housing. The invention solves the problem of the traditional automobile rear axle. The problem of sealing the equipment in the hydraulic bulging of the shell; significantly improving the formability of the rear axle housing of the automobile, reducing the mold clamping force during the forming process, reducing the thinning rate of the formed part and even the possibility of rupture; using vibration plastic forming The method can reduce the plastic deformation resistance of the tube blank, improve the processing quality of the automobile rear axle housing and reduce the processing energy consumption. At the same time, the relative movement conditions between the mold and the workpiece have been improved, avoiding the forming process "Self-locking" occurs between solid particles in the medium.

Description

Thermal expansion and vibration composite forming process of solid particles of automobile rear axle housing

technical field

The invention relates to a pipe bulging process, in particular to a thermal expansion and vibration composite forming process of solid particles of an automobile rear axle housing.

technical background

As an important part of the car, the rear axle housing of the car plays the role of carrying the body and protecting the final drive. Traditional automobile rear axle housings are formed by stamping welding or casting. However, welded parts are prone to welding defects; the casting process wastes materials and is not environmentally friendly. In recent years, some scholars have proposed the method of internal high-pressure forming, in which high-pressure liquid is introduced into the pipe, and the ideal formed part is obtained through the bulging of the pipe, and then the expansion-compression composite forming method is proposed to reduce the amount of time spent in the forming process of the rear axle housing of the automobile. The required forming pressure and improve the quality of formed parts. However, the method of using the internal high pressure forming automobile rear axle housing needs to strictly consider the sealing problem of the equipment, and due to the limitation of the internal high pressure forming equipment, it is impossible to improve the formability of the formed parts by increasing the forming temperature. Generally, the internal high pressure forming is carried out at room temperature, and the formability of the formed parts is poor. During the process of internal high pressure forming of the automobile rear axle housing, the forming pressure is relatively high, and the tube blank is prone to rupture due to the uniform distribution of liquid pressure on the surface of the tube blank. Phenomenon.

Solid particle medium forming is a new forming process proposed in recent years. The forming medium uses solid particles, such as fine sand, steel balls, ceramic particles, etc. Therefore, the solid particle medium forming process does not need to strictly consider the sealing problem in the forming process. The solid particle medium forming process presents inhomogeneous pressure on the tube blank during the forming process, and the formed part can be locally formed by controlling the feed rate of the pressure head. During the forming process of the bulging part, the formability of the formed part can be significantly improved by heating the tube blank and the solid particle medium, so that the forming quality of the formed part can be improved and the possibility of cracking of the formed part can be reduced. At present, the research on solid particle medium forming technology has involved sheet metal forming and bellows forming, and the solid particle medium forming process has been successfully used to obtain good formed parts; however, the application of solid particle medium forming technology to the forming of automobile rear axle housings There are reports.

In recent years, vibration plastic forming technology has been widely used in the plastic forming of materials. Compared with ordinary plastic forming methods, the application of vibration plastic processing technology in the process of material plastic forming can reduce the plastic deformation resistance of materials and improve the processing quality of formed parts. And reduce the processing energy consumption, while the relative movement conditions between the mold and the workpiece are improved, but the vibration plastic forming technology has not been applied to the forming of the automobile rear axle housing.

Contents of the invention

In order to overcome the above-mentioned shortcoming of the prior art, the object of the present invention is to provide a kind of thermal expansion and vibration composite forming process of the solid particles of the rear axle housing of the automobile, which can significantly improve the formability of the rear axle housing of the automobile. The mold force is reduced, and the thinning rate and even the possibility of cracking of the formed part are reduced.

In order to achieve the above object, the technical scheme that the present invention takes is:

A thermal expansion and vibration composite forming process of solid particles of an automobile rear axle housing comprises the following steps:

Step 1, diameter reduction treatment, to obtain the diameter reduction tube blank 11:

First, select GB/T8162-2008 standard seamless steel pipe 10 according to the size and bulging requirements of the rear axle housing of the automobile, wherein the ratio of the diameter of the seamless steel pipe 10 to the maximum equivalent diameter of the axle housing is greater than 0.5; Processing, wherein the number of pipe diameter reduction passes is not more than 4 times, and the diameter reduction rate of each pass is less than 15%. After the diameter is completed, it is stress-relieved annealed;

Step 2, heating and assembling a bulging mold:

Mix the solid particles grinded in the graphite powder into the reduced-diameter tube blank 11, the solid particles are steel balls or ceramic balls, use the left indenter 3 and the right indenter 3' to seal and heat the seal as a whole, so that The temperature of the reduced-diameter tube blank 11 is 500-650°C; the primary bulging left half mold 2, the primary bulging right half mold 2', the first upper guide mold 4 and the first lower guide mold 4' are preheated to 250-650°C. 300°C, assemble the whole seal, the primary bulging left half mold 2, the primary bulging right half mold 2', the first upper guide mold 4 and the first lower guide mold 4', and then put the assembly on the hydraulic press workbench superior;

Step 3, one-time bulging to obtain one-time bulging tube blank 12:

Apply hydraulic vibration, mechanical vibration or ultrasonic vibration to the first upper guide mold 4 and the first lower guide mold 4', wherein the vibration frequency is 10-15KHz; first, the left half mold 2 and the right half mold 2' are bulged once Drive the left indenter 3 and the right indenter 3' to move relative to each other at a speed of 15-20mm/s, and the axial force and solid particles of the shrinking tube blank 11 in the first bulging left half mold 2 and the first bulging right half mold 2' Beneficial wrinkles are produced under the action of extrusion, and the mold stops moving when it meets the predetermined stroke; then the left indenter 3 and the right indenter 3' move relative to each other at a speed of 5 to 10 mm/s, and the left indenter 3 and the right indenter 3' are extruded The solid particles make the reduced-diameter tube blank 11 gradually fit the mold, thereby gradually completing a bulge to obtain a bulge tube 12;

Step 4, heating again, assembling the secondary bulging mold:

Take out the primary bulging tube 12, put the solid particles grinded in the graphite powder into the primary bulging tube 12, seal it with the left indenter 3 and the right indenter 3' and heat the seal as a whole, so that the primary The temperature of the bulging tube blank 12 is 500-650°C; the secondary bulging left half mold 6, the secondary bulging right half mold 6', the second upper guiding mold 5 and the second lower guiding mold 5' are preheated to 250～300℃, assemble the sealing body, secondary bulging left half mold 6, secondary bulging right half mold 6', second upper guide mold 5 and second lower guide mold 5', and then place the assembly on the hydraulic press table;

Step 5, secondary bulging to obtain the secondary bulging tube blank 13:

Apply hydraulic vibration, mechanical vibration or ultrasonic vibration to the second upper guide mold 5 and the second lower guide mold 5', wherein the vibration frequency is 10-15KHz; 6' drives the left indenter 3 and the right indenter 3' to move relative to each other at a speed of 15-20mm/s, and the primary bulging tube blank 12 is in the axial direction of the secondary bulging left half mold 6 and the secondary bulging right half mold 6' Beneficial wrinkles are produced under the action of force and solid particle extrusion, and the movement stops when the mold is closed; then the left indenter 3 and the right indenter 3' move relative to each other at a speed of 5-10mm/s, and the left indenter 3 and the right indenter 3 'Squeeze the solid particles so that the primary bulging tube 12 gradually fits the mold, thereby gradually completing the secondary bulging to obtain the secondary bulging tube 13;

Step 6, heating three times, assembling the pressing mold:

Take out the secondary bulging tube blank 13, put the solid particles grinded in the graphite powder into the secondary bulging tube blank 13, seal it with the left indenter 3 and the right indenter 3' and heat the sealed whole, The temperature of the secondary bulging tube blank 13 is 500-650°C; the left pressing die 8, the right pressing die 8', the upper pressing die 7, the lower pressing die 7', the left positioning sleeve 9, and the right positioning sleeve 9 'Preheat to 250-300°C; assemble the overall seal, the left pressing mold 8, the right pressing mold 8', the upper pressing mold 7, the lower pressing mold 7', the left positioning sleeve 9 and the right positioning sleeve 9', Then place the assembly on the hydraulic press table;

Step 7, pressing to obtain the formed part 14 of the automobile rear axle housing:

The left pressing die 8, the right pressing die 8', the upper pressing die 7 and the lower pressing die 7' move relatively at a speed of 15-20 mm/s at the same time, and the secondary bulging tube blank 13 is extruded by the solid particles and the die The lower dies are fitted step by step; the left pressing head 3 and the right pressing head 3' are extruded by solid particles during the pressing process of the rear axle housing and move outward freely, and the left pressing die 8, the right pressing die 8', and the upper pressing die 7 and the lower pressing mold 7' stop moving after clamping, and finally obtain the formed part 14 of the rear axle housing of the automobile.

The particle size range of the solid particles is 1-4mm.

The present invention has the following advantages:

1. Solid particles are used as the force transmission medium in the forming process of the automobile rear axle housing, which solves the problem of equipment sealing in the hydraulic bulging of the traditional automobile rear axle housing.

2. By heating the tube billet and solid particles and properly controlling the temperature difference between the two, the formability of the rear axle housing of the automobile can be significantly improved, the mold clamping force is reduced during the forming process, and the thinning rate of the formed part is even broken. reduced sex.

3. Vibration plastic forming is used in the bulging process of the automobile rear axle housing, which can reduce the plastic deformation resistance of the tube blank, improve the processing quality of the automobile rear axle housing and reduce the processing energy consumption. At the same time, the distance between the mold and the workpiece The relative movement conditions have been improved, and the "self-locking" between solid particles during the forming process of the automobile rear axle housing has been avoided.

Description of drawings

Fig. 1 is the initial state of the seamless steel pipe in the present invention.

Fig. 2 is the pipe blank after the diameter of the seamless steel pipe is reduced in the present invention.

Fig. 3 is a schematic diagram of the initial state of the primary bulging process of the automobile rear axle housing in the present invention.

Fig. 4 is a schematic diagram of the intermediate state in the primary bulging process of the automobile rear axle housing in the present invention.

Fig. 5 is a schematic diagram of the completed state of the primary bulging process of the automobile rear axle housing in the present invention.

Fig. 6 is a schematic diagram of the initial state of the secondary bulging process of the automobile rear axle housing in the present invention.

Fig. 7 is a schematic diagram of the intermediate state of the secondary bulging process of the automobile rear axle housing in the present invention.

Fig. 8 is a schematic diagram of the completion state of the secondary bulging process of the automobile rear axle housing in the present invention.

Fig. 9 is a schematic diagram of the initial state of the automobile rear axle housing pressing process in the present invention.

Fig. 10 is a schematic longitudinal sectional view of the initial state of the automobile rear axle housing pressing process in the present invention.

Fig. 11 is a schematic diagram of the completion state of the automobile rear axle housing pressing process in the present invention.

Fig. 12 is a schematic longitudinal sectional view of the finished pressing process of the rear axle housing of the automobile in the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

A thermal expansion and vibration composite forming process of solid particles of an automobile rear axle housing comprises the following steps:

Step 1, diameter reduction treatment, to obtain the necked tube blank 11:

Referring to Figure 1, firstly, according to the size of the rear axle housing of the automobile and the bulging requirements, a seamless steel pipe 10 with a specification of 114*4 is selected, and then it is subjected to four passes of cold pushing and shrinking treatment, among which, two passes of diameter reduction are completed. Stress relief annealing;

Step 2, heating and assembling a bulging mold:

Referring to Figure 2 and Figure 3, put the solid particles run-in in the graphite powder into the reduced-diameter tube blank 11, select a steel ball 1 with a diameter of 1mm for the solid particles, and seal it with the left pressure head 3 and the right pressure head 3' And heat the sealed whole, so that the temperature of the reduced-diameter tube blank 11 is 500-650 °C; the first bulging left half mold 2, the first bulging right half mold 2', the first upper guide mold 4 and the second lower guide The mold 4' is preheated to 250-300°C, and the whole seal, the primary bulging left half mold 2, the primary bulging right half mold 2', the first upper guide mold 4 and the second lower guide mold 4' are assembled, and then Place the assembly on the hydraulic press table;

Step 3, one-time bulging to obtain one-time bulging tube blank 12:

Referring to Fig. 4, ultrasonic vibration is applied to the first upper guide mold 4 and the first lower guide mold 4', wherein the vibration frequency is 15KHz; firstly, the left half-mold 2 and the right half-mold 2' of the first bulging drive the left indenter 3. The right indenter 3' moves relatively at a speed of 20mm/s, and the reduced diameter tube blank 11 is produced under the extrusion action of the steel ball 1 and the axial force of the left half mold 2 for one bulge, the right half mold 2' for one bulge It is beneficial to folds, and stops when the mold meets the predetermined stroke; then referring to Figure 5, the left indenter 3 and the right indenter 3' move relative to each other at a speed of 10mm/s, and the left indenter 3 and the right indenter 3' squeeze the steel ball 1 The reduced-diameter tube blank 11 gradually fits the mold, thereby gradually completing a bulge to obtain a bulge tube 12;

Step 4, heating again, assembling the secondary bulging mold:

Take out the primary bulging tube blank 12, put the steel ball 1 run-in in the graphite powder into the primary bulging tube blank 12, seal it with the left indenter 3 and the right indenter 3' and heat the seal as a whole, so that The temperature of the primary bulging tube blank 12 is 500-650°C; the secondary bulging left half mold 6, the secondary bulging right half mold 6', the second upper guiding mold 5 and the second lower guiding mold 5' are preheated To 250 ~ 300 ℃, referring to Fig. 6, assemble the whole seal, secondary bulging left half mold 6, secondary bulging right half mold 6', second upper guide mold 5 and second lower guide mold 5', Then place the assembly on the hydraulic press table;

Step 5, secondary bulging to obtain the tube blank 13:

Referring to Fig. 7, ultrasonic vibration is applied to the second upper guide mold 5 and the second lower guide mold 5', wherein the vibration frequency is 15KHz; first, the secondary bulging left half mold 6 and the secondary bulging right half mold 6' drive the The indenter 3 and the right indenter 3' move relative to each other at a speed of 20 mm/s. The primary bulging tube blank 12 is squeezed by the axial force of the secondary bulging left half mold 6 and the secondary bulging right half mold 6' with the steel ball 1. Beneficial wrinkles are produced under the action of pressure, and the movement stops when the mold is closed; then referring to Figure 8, the left indenter 3 and the right indenter 3' move relative to each other at a speed of 10 mm/s, and the left indenter 3 and the right indenter 3' squeeze The steel ball 1 makes the primary bulging tube blank 12 gradually fit the mold, thereby gradually completing the secondary bulging to obtain the secondary bulging tube blank 13;

Step 6, heating three times, assembling the pressing mold:

Take out the secondary bulging tube blank 13, put the steel balls run-in in the graphite powder into the secondary bulging tube blank 13, seal it with the left indenter 3 and the right indenter 3' and heat the seal as a whole, The temperature of the secondary bulging tube blank 13 is 500-650°C; the left pressing die 8, the right pressing die 8', the upper pressing die 7, the lower pressing die 7', the left positioning sleeve 9, and the right positioning sleeve 9 'Preheat to 250-300°C, refer to Figure 9 and Figure 10, for the overall sealing, left pressing mold 8, right pressing mold 8', upper pressing mold 7, lower pressing mold 7', left positioning sleeve 9 and right positioning Sleeve 9' is assembled, and then the assembly is placed on the hydraulic press table;

Step 7, pressing to obtain the formed part 14 of the automobile rear axle housing:

Referring to Fig. 11 and Fig. 12, the left pressing die 8, the right pressing die 8', the upper pressing die 7 and the lower pressing die 7' move relative to each other at a speed of 20mm/s at the same time, and the secondary bulging tube blank 13 is formed between the steel ball 1 and the lower pressing die 7'. Under the co-extrusion of the molds, the molds are gradually fitted; the left pressure head 3 and the right pressure head 3' are free to move outwards by the extrusion of the steel ball 1 during the pressing process of the rear axle housing, and the left pressing mold 8 and the right pressing The die 8', the upper pressing die 7, and the lower pressing die 7' stop moving after mold closing, and the formed part 14 of the automobile rear axle housing is obtained.

Claims (2)

1. a heat expansion vibration combined forming process for the solid particle of automobile rear axle housing, is characterized in that, comprise the following steps:

Step 1, undergauge process, obtains undergauge pipe (11):

First require to choose GB/T8162-2008 standard seamless steel pipe (10) according to automobile rear axle housing size and bulging, wherein, the diameter of seamless steel pipe (10) and the maximum equivalent diameter ratio of axle housing are greater than 0.5; Then cold push-sinking process is carried out to it, wherein no more than 4 times of tubing undergauge passage, every time diameter reducing rate is less than 15%, if required undergauge passage is greater than two passages, carries out stress relief annealing in seamless steel pipe (10) undergauge process after every two passage undergauges to it;

Step 2, heating, assemble an expanding die:

The solid particle of break-in in powdered graphite is loaded in undergauge pipe (11), solid particle is steel ball or Ceramic Balls, seal with left pressure head (3) and right pressure head (3 ') carrying out and sealing entirety is heated, making the temperature of undergauge pipe (11) be 500 ~ 650 DEG C; Guide die (4) and first time guide die (4 ') on left half mold of bulging (2), right half mold (2 ') of bulging, first are preheating to 250 ~ 300 DEG C, on, left half mold of bulging (2) overall to sealing, right half mold (2 ') of bulging, first, guide die (4) and first time guide die (4 ') are assembled, and are then placed on hydraulic press workbench by assembly;

Step 3, a bulging, obtains a bulging pipe (12):

Apply hydraulic vibration, mechanical oscillation or ultrasonic vibration to guide die (4) on first and first time guide die (4 '), wherein vibration frequency is 10 ~ 15KHz; First the left half mold of bulging (2), the right half mold of a bulging (2 ') drive left pressure head (3), right pressure head (3 ') with the relative motion of 15 ~ 20mm/s speed, undergauge pipe (11) produces useful fold, stop motion when mould meets predetermined stroke under the axial force and solid particle squeezing action of a left half mold of bulging (2), the right half mold of a bulging (2 '); Then left pressure head (3) and right pressure head (3 ') are with the relative motion of 5 ~ 10mm/s speed, left pressure head (3) and right pressure head (3 ') extrusion solid particle make undergauge pipe (11) to fit gradually mould, thus progressively complete a bulging and obtain a bulging pipe (12);

Step 4, heats again, assembling secondary expanding die:

Take out a bulging pipe (12), the solid particle of break-in in powdered graphite is loaded in a bulging pipe (12), seal with left pressure head (3) and right pressure head (3 ') carrying out and sealing entirety is heated, making the temperature of a bulging pipe (12) be 500 ~ 650 DEG C; Guide die (5) and second time guide die (5 ') on left for secondary bulging half mold (6), the right half mold (6 ') of secondary bulging, second are preheating to 250 ~ 300 DEG C, guide die (5) and second time guide die (5 ') on sealing entirety, the left half mold of secondary bulging (6), the right half mold (6 ') of secondary bulging, second are assembled, then assembly is placed on hydraulic press workbench;

Step 5, secondary bulging, obtains secondary bulging pipe (13):

Apply hydraulic vibration, mechanical oscillation or ultrasonic vibration to guide die (5) on second and second time guide die (5 '), wherein vibration frequency is 10 ~ 15KHz; First the left half mold of secondary bulging (6), the right half mold of secondary bulging (6 ') drive left pressure head (3), right pressure head (3 ') with the relative motion of 15 ~ 20mm/s speed, one time bulging pipe (12) produces useful fold, stop motion when mould matched moulds under the left half mold of secondary bulging (6), secondary bulging right half mold (6 ') axial force and solid particle squeezing action; Then left pressure head (3) and right pressure head (3 ') are with the relative motion of 5 ~ 10mm/s speed, left pressure head (3) and right pressure head (3 ') extrusion solid particle make a bulging pipe (12) to fit gradually mould, thus progressively complete secondary bulging and obtain secondary bulging pipe (13);

Step 6, three heating, assembling compacting tool set:

Take out secondary bulging pipe (13), the solid particle of break-in in powdered graphite is loaded in secondary bulging pipe (13), seal with left pressure head (3) and right pressure head (3 ') carrying out and sealing entirety is heated, making the temperature of secondary bulging pipe (13) be 500 ~ 650 DEG C; Left compacting tool set (8), right compacting tool set (8 '), upper compacting tool set (7), lower compacting tool set (7 '), left abutment sleeve (9), right abutment sleeve (9 ') are preheating to 250 ~ 300 DEG C; Sealing entirety, left compacting tool set (8), right compacting tool set (8 '), upper compacting tool set (7), lower compacting tool set (7 '), left abutment sleeve (9) and right abutment sleeve (9 ') are assembled, then assembly is placed on hydraulic press workbench;

Step 7, compacting, obtains automobile rear axle housing drip molding (14):

Left compacting tool set (8), right compacting tool set (8 '), upper compacting tool set (7) and lower compacting tool set (7 ') are simultaneously with the speed relative motion of 15 ~ 20mm/s, and secondary bulging pipe (13) is progressively fitted mould under the common squeezing action of solid particle and mould; Left pressure head (3) and right pressure head (3 ') are subject to the outside freely-movable of solid particle squeezing action in rear axle case pressing process, stop motion after left compacting tool set (8), right compacting tool set (8 '), upper compacting tool set (7) and lower compacting tool set (7 ') matched moulds, finally obtains automobile rear axle housing drip molding (14).

2. the heat expansion vibration combined forming process of the solid particle of a kind of automobile rear axle housing according to claim 1, is characterized in that: the particle size range of described solid particle is 1 ~ 4mm.