CN113815178A

CN113815178A - Foaming forming die for split surface soft sealing

Info

Publication number: CN113815178A
Application number: CN202010564297.XA
Authority: CN
Inventors: 黄灵夫; 顾鹏
Original assignee: Wuhan Senbo Junyu Technology Development Co ltd
Current assignee: Wuhan Senbo Junyu Technology Development Co ltd
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2021-12-21
Anticipated expiration: 2040-06-19
Also published as: CN113815178B

Abstract

The invention discloses a split-type surface soft sealing foaming forming die, which belongs to the technical field of die processing technology and comprises an upper die and a lower die which are closed to form a die, wherein a cavity and a parting surface to be processed are arranged in the die, the parting surface comprises an upper die parting surface and a lower die parting surface, one of the parting surfaces is provided with a U-shaped groove, the other parting surface is provided with an air groove, a hollow sealing ring is embedded in an accommodating space formed by the air groove and the U-shaped groove in a matching mode, and the volume of the sealing ring is larger than the volume of the accommodating space. According to the invention, the height and the thickness of the sealing ring can be expanded by the restoring deformation force of the sealing ring, the gap between the parting surfaces can be compensated, the upper and lower parting surfaces are tightly jointed and pressed more tightly, a better sealing effect is realized, the flash phenomenon during product molding is reduced, and finally the product has the advantages of attractive appearance, stable size, few bad defects, low production cost and great improvement on the product percent of pass.

Description

Foaming forming die for split surface soft sealing

Technical Field

The invention relates to the technical field of mold processing technologies, in particular to a split-type surface soft sealing foaming forming mold.

Background

The automobile seat back plate is generally molded by using a mold during production; the automobile seat back plate mold comprises an upper mold and a lower mold, wherein a workpiece is taken out when the upper mold and the lower mold are separated, and a pouring gun is adopted to pour raw materials into a lower mold cavity when the mold is closed. Because the shape of the automobile backboard plastic part is often complex, the parting surfaces of the upper die and the lower die of the die are complex curved surfaces; according to the production process requirements, the parting surface of the die needs to be sealed to seal the raw materials, and simultaneously, the gas is allowed to permeate, but the materials cannot leak. The mould with well-repaired parting surface has no flash and does not need manual polishing.

The traditional mode of die matching is to mount a die on a die frame, repeatedly coat red powder on a parting surface, continuously match and open the die, use an alloy file or a pneumatic grinding wheel to grind and match a contact area after opening the die, and finally achieve the joint of the parting surfaces of the upper die and the lower die. The mode has high requirement on the master of a bench worker for the work bottom, long mold matching time and poor effect; and the product has more flash due to the shallow parting surface of part of the mould product and the characteristic of the foaming raw material. At present, spark parting surface processing technologies are generally adopted, such as the literature 'sinking flood, electric spark parting surface die assembly processing [ J ]. electromachining, 1979(05): 46-47' and the literature 'giving attention to the ambition, the electric spark parting surface processing technology of an automobile seat foaming die [ J ]. die manufacturing, 2014,14(6): 82-83', and the disclosed modes are adopted, local and instant high temperature is generated through continuous pulse spark discharge, high points on the parting surface are etched one by one, the contact area is continuously expanded, and finally the requirement of cavity sealing is met. However, the electric spark machining process is complex and high in cost; and the mould often adopts aluminium system, and spark discharge is fragile to hinder the die joint, can lead to the die joint to warp in long-term use, wearing and tearing etc. make the product appear burr overlap easily, and outward appearance and precision can not obtain guaranteeing, follow-up must carry out the deburring, increased the human cost, and the incomplete trimming of polishing can also lead to the cladding seat to produce hard spot arch, leads to customer complains about.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a foaming forming die for soft sealing of parting surfaces, which deforms through extrusion of a sealing ring, so that the upper parting surface and the lower parting surface are better jointed, the height and the thickness of the sealing ring can be expanded through the restoring deformation force of the sealing ring, the gap between the parting surfaces can be compensated, the upper parting surface and the lower parting surface are tightly jointed and pressed, a better sealing effect is realized, the flash phenomenon during product forming is reduced, the appearance of a product is attractive, the size of the product is stable, the defect is few, the production cost is low, and the product percent of pass is greatly improved. .

In order to achieve the purpose, the invention is realized by the following technology:

the utility model provides a soft confined foaming forming die of parting surface, includes that mould and lower mould fold the back and form the mould, be equipped with the die cavity in the mould and treat the die joint of processing, the die joint includes mould die joint and lower mould die joint, one of them the die joint is equipped with U type groove, another be equipped with the air tank on the die joint, the air tank with the U type groove is equipped with a hollow sealing washer to the embedded holding space that forms of closing, the volume of sealing washer is greater than the holding space's volume.

Adopt above-mentioned technical scheme: the sealing ring body is not easy to deform in a non-working state; when the upper die and the lower die are assembled, the sealing ring is extruded, the hollow structure can be compressed under the action of certain pressure to generate certain deformation, so that the sealing surface of the sealing ring can be better attached to the parting surface of the upper die and the lower die, and a better sealing effect is realized; after the foaming raw material is poured, the parting surface is easy to have the problem of untight pressing due to the principle of expansion with heat and contraction with cold, so that the foaming raw material melt flows into the parting surface gap to form a flash. Secondly, in the foaming injection molding process, if the pressure of the cavity is too high, high-pressure gas in the cavity can be rapidly discharged through the gas groove, the exhaust performance is good, and the impact pressure of exhaust is effectively relieved. Therefore, through the structure, the close fit and the air permeability of the parting surface of the foaming mold are ensured. In addition, the invention has simple structure, reduces the die change cost and risk and shortens the die change period.

Furthermore, the distance between the U-shaped groove and the boundary line between the parting surface and the cavity is 3-5 mm. The sealing ring is away from the high-temperature melt of the cavity by a certain distance, so that the service life of the sealing ring is prolonged, and the sealing effect of the parting surface is influenced if the distance is too long.

Furthermore, a chamfer is arranged on one side, facing the air groove, of the sealing ring. Make the die joint can be under the guide effect of chamfer with the better laminating of the sealed face of sealing washer through the chamfer, prevent the production of overlap, consequently the chamfer size is also difficult too big, designs for diameter 0.5 ~ 1.5mm to be good.

Further, the width of the air groove is 9-11 mm, and the depth of the air groove is 0.3-0.7 mm;

further, the groove width of the air groove is 10mm and the groove depth is 0.5 mm.

Further, the sealing ring comprises a trapezoid section and an arc section which are in smooth transition, wherein the small-diameter end of the trapezoid section is connected with the arc section, and the length of the small-diameter end is the same as the diameter of the arc; the length of the small-diameter end of the trapezoid section is 8-10 mm, the length of the large-diameter end of the trapezoid section is 9-11 mm, the height of the trapezoid section is 4-6 mm, and the diameter of the circular arc section is 8-10 mm.

Further, the length of the small-diameter end of the trapezoid section is 9mm, the length of the large-diameter end of the trapezoid section is 10mm, the height of the trapezoid section is 5mm, the diameter of the arc section is 9mm, and the height of the sealing ring is 9.5 mm.

Further, the U-shaped groove comprises a conical section and an arc section which are in smooth transition, a large-diameter end of the conical section is connected with the arc section, and the length of the large-diameter end is the same as the diameter of the arc; the length of the small-diameter end of the conical section is 8-9 mm, the length of the large-diameter end of the conical section is 8-10 mm, the height of the conical section is 3-5 mm, and the diameter of the arc section is 8-10 mm.

Further, the length of the small-diameter end of the conical section is 8.6mm, the length of the large-diameter end of the conical section is 9mm, the height of the conical section is 4mm, the diameter of the arc section is 4.5mm, and the depth of the U-shaped groove is 8.5 mm.

Furthermore, the sealing ring is 0.3-1.5 mm higher than the U-shaped groove.

Furthermore, the sealing ring is 1mm higher than the U-shaped groove.

Adopt above-mentioned technical scheme: the taper section in U type groove is opposite structure with the trapezoidal section of sealing washer, can be better with the locking of sealing washer in U type inslot, improves sealed effect, sets up the groove width of gas tank simultaneously and holds length unanimous for the trapezoidal section major diameter with the sealing washer, can not influence the leakproofness of mould to the foaming material like this, still can increase the gas permeability of die joint. And each section parameter of the U-shaped groove and the sealing ring is set carefully, so that the material sealing and the exhaust of the parting surface sealing device are ensured to reach the optimal state simultaneously, the problem of flash on the parting surface is effectively solved, and the product prepared by the foaming forming die with soft sealing of the parting surface has little or no flash, thereby greatly improving the processing quality of the product.

The invention has the beneficial effects that:

1. receive the extrusion through the sealing washer, produce and warp, the die joint is laminated better about making, and the reply deformability of sealing washer makes its high thickness extensible moreover, can compensate the die joint clearance, and the die joint laminating is inseparable about making, and the pressfitting is inseparable also, realizes better sealed effect, and the overlap phenomenon when reducing the product shaping finally makes product outward appearance pleasing to the eye, stable in size, bad defect are few, low in production cost, very big improvement the product percent of pass. Secondly, when the pressure of the cavity is overlarge, high-pressure gas in the cavity can be quickly discharged through the gas groove. Therefore, the close fit and air permeability of the parting surface of the foaming mold are ensured.

2. The taper section in U type groove is opposite structure with the trapezoidal section of sealing washer, can be better with the locking of sealing washer in U type inslot, improves sealed effect, sets up the groove width of gas tank simultaneously and holds length unanimous for the trapezoidal section major diameter with the sealing washer, can not influence the leakproofness of mould to the foaming material like this, still can increase the gas permeability of die joint. And each section parameter of the U-shaped groove and the sealing ring is set carefully, so that the material sealing and the air exhaust of the parting surface sealing device can reach the optimal state at the same time.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural view of a split-surface soft-seal foam molding die of example 1;

FIG. 2 is a schematic view of the structure of the parting surface of the upper mold of example 1;

FIG. 3 is a schematic view of the structure of the parting surface of the lower mold in example 1;

FIG. 4 is a schematic structural view of a seal ring according to embodiment 1;

in the figure, 1, an upper die; 2. a lower die; 3. a cavity; 4. parting surfaces; 41. parting surface of the upper die; 42. parting surfaces of the lower die; 5. a U-shaped groove; 51. a tapered section; 52. an arc-shaped section; 6. an air tank; 7. a seal ring; 71. a trapezoidal section; 72. a circular arc section; 8. chamfering;

FIG. 5 is a T-test analysis of the effect of air slot depth on product flash length;

FIG. 6 is a T-test analysis of the effect of air bag pressure on product flash length;

FIG. 7 is a T-test analysis of the effect of parting plane sealing patterns on product flash length;

FIG. 8 is a graph of the effect of DOE experiments on degradation; in the graph, A is a Pareto graph, B is a main effect graph, and C is an interaction graph;

FIG. 9 is a graph of the effect of DOE experiments on mean values; in the graph, A is a Pareto graph, B is a main effect graph, and C is an interaction graph;

FIG. 10 is a diagram of a product produced by different sealing methods according to an application example; in the drawing, a is an electric spark sealing method, and B is a soft sealing method according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

Example 1

A foaming forming die with a parting surface 4 soft seal comprises an upper die 1 and a lower die 2, wherein the upper die 1 and the lower die 2 form the die after being closed, a die cavity 3 and a parting surface 4 to be processed are arranged in the die, the parting surface 4 is distributed around the die cavity 3, the parting surface 4 comprises an upper die 1 parting surface 4 and a lower die 2 parting surface 4, a cavity formed in the die after the upper die 1 parting surface 4 is attached to the lower die 2 parting surface 4 is a die cavity 3, a U-shaped groove 5 is arranged at a position 3-5 mm away (L6) away from the boundary line of the parting surface 4 and the die cavity 3 on one of the parting surfaces 4, an air groove 6 is arranged on the other parting surface 4, the position of the air groove 6 corresponds to the U-shaped groove 5, and a hollow sealing ring 7 is embedded in an accommodating space formed by the air groove 6 and the U-shaped groove 5 in a matching way, namely, the center of the sealing ring 7 is provided with a cavity with a circular section, so as to form a hollow structure; the shape of the sealing ring 7 is matched with the U-shaped groove 5, namely the shape of the sealing ring 7 is of a U-shaped structure, and the volume of the sealing ring 7 is larger than the volume of an accommodating space formed by the air groove 6 and the U-shaped groove 5 in a matching mode, so that the sealing ring 7 is higher than the U-shaped groove 5 and forms interference fit in the accommodating space. In a specific embodiment, the U-shaped groove 5 can be arranged on the parting surface 4 of the lower die 2 or on the parting surface 4 of the upper die 1, when the U-shaped groove is arranged on the parting surface 4 of the lower die 2, the air groove 6 is arranged on the parting surface 4 of the upper die 1, and trace residue of foaming raw materials can appear on the upper die 1, so that manual cleaning is inconvenient, and mechanical arm cleaning is facilitated; establish on last mould 1 die joint 4 when the U-shaped groove, then gas tank 6 sets up on lower mould 2 die joint 4, and the residue of foaming raw materials does benefit to manual clearance on lower mould 2, and is unfavorable for automatic clearance. According to the operating mode demand, preferably the U-shaped groove is established on last mould 1 die joint 4, and gas tank 6 sets up on 2 die joint 4 of lower mould, see figure 1. The sealing ring 7 may be made of isoprene rubber (polyisoprene rubber), and in this embodiment, the sealing ring 7 is made of a gas-phase silica gel sealing ring 7 (available from starlight technologies, ltd., product model number RBB-2420). Sealing washer 7 is gone up towards one side of gas tank 6 is equipped with chamfer 8 for lower die joint 4 can be under the guide effect of chamfer 8 with the better laminating of the bottom surface of sealing washer 7, prevents the production of overlap, and chamfer 8 size is that the diameter is 0.5 ~ 1.5mm is good.

The working principle of the invention is as follows: when the upper die and the lower die 2 are assembled, the sealing ring 7 is extruded to deform, the upper and the lower parting surfaces 4 are well attached, after the foaming raw materials are poured, the parting surfaces 4 are not tightly pressed due to expansion caused by heat and contraction caused by cold, then the height and the thickness of the parting surfaces can be expanded by the aid of the restoring deformation force of the sealing ring 7, gaps among the parting surfaces 4 are compensated, the upper and the lower parting surfaces 4 are tightly attached, the pressing is more tight, a better sealing effect is achieved, the flash phenomenon during product forming is reduced, and finally, the product is attractive in appearance, stable in size, few in adverse defects, low in production cost and greatly improved in product percent of pass. Secondly, when the pressure of the cavity 3 is too high, the high-pressure gas in the cavity 3 can be rapidly discharged through the gas groove 6. Therefore, the adhesion and air permeability of the parting surface 4 of the foaming mold are ensured. In addition, the invention has simple structure, reduces the die change cost and risk and shortens the die change period.

According to the working principle of the sealing ring 7: the adhesion and the air permeability are related to the sum of the volume of the seal ring 7 and the volumes of the U-shaped groove 5 and the air groove 6, that is, the deformation amount of the seal ring 7 is limited by the above-mentioned structure, and the adhesion and the air permeability are affected. Since the upper and lower parting surfaces 4 need to maintain not only good sealing effect but also good air permeability, in a further embodiment of the invention, the following is preferably provided: referring to FIG. 3, the gas groove 6 has a groove width (L1) of 9 to 11mm and a groove depth (D1) of 0.3 to 0.7 mm. Referring to fig. 4, the sealing ring 7 includes a trapezoid section 71 and an arc section 72 in smooth transition, a small diameter end of the trapezoid section 71 is connected to the arc section 72, and the length of the small diameter end is the same as the diameter of the arc; the big footpath end of trapezoidal section 71 with the cell wall of air pocket 6 meets and big footpath end length is the same with the groove width of air pocket 6, the length of the path end of trapezoidal section 71 (L2) is 8 ~ 10mm and big footpath end length (L3) is 9 ~ 11mm, the height of trapezoidal section 71 is 4 ~ 6mm (D2), the circular arc diameter (phi 1) of circular arc section 72 is 8 ~ 10 mm. Referring to fig. 2, the U-shaped groove 5 comprises a smoothly-transitional conical section 51 and an arc-shaped section 52, wherein the large-diameter end of the conical section 51 is connected with the arc-shaped section 52 and the length of the large-diameter end is the same as the diameter of the arc; the length (L4) of the small-diameter end of the conical section 51 is 8-9 mm, the length (L5) of the large-diameter end of the conical section 51 is 8-10 mm, the height (D3) of the conical section 51 is 3-5 mm, and the diameter (phi 2) of the arc-shaped section 52 is 8-10 mm. The sealing ring 7 is 50.3-1.5 mm higher than the U-shaped groove (D4).

In this embodiment, the width of the air groove 6 is 10mm and the depth of the air groove is 0.5 mm. The length of the small-diameter end of the trapezoid section 71 is 9mm, the length of the large-diameter end of the trapezoid section 71 is 10mm, the height of the trapezoid section 71 is 5mm, the diameter of the arc section 72 is 9mm, and the height of the sealing ring 7 is 9.5 mm. The length of the small-diameter end of the conical section 51 is 8.6mm, the length of the large-diameter end of the conical section 51 is 9mm, the height of the conical section 51 is 4mm, the diameter of the arc-shaped section 52 is 4.5mm, and the depth of the U-shaped groove 5 is 8.5 mm. The sealing ring 7 is 51mm higher than the U-shaped groove.

The setting of above-mentioned structure, the toper section 51 of U type groove 5 is opposite structure with the trapezoidal section 71 of sealing washer 7, can be better with sealing washer 7 locking in U type groove 5, improves sealed effect, sets up the groove width of gas tank 6 simultaneously and holds length unanimous for the big footpath of trapezoidal section 71 with sealing washer 7, can not influence the leakproofness of mould to the foaming material like this, still can increase the gas permeability of die joint 4. And the parameters of the U-shaped groove 5 and the sealing ring 7 are set carefully, so that the sealing and exhausting of the sealing device of the parting surface 4 can reach the optimal state at the same time.

Example 2 parameter optimization

Through analysis in the early stage, the depth of the air groove, the pressure of the air bag and the sealing mode of the parting surface are potentially important factors influencing the length of the flash. More detailed parameter optimization was performed by further single factor analysis and DOE (DESIGN OF experimenter) EXPERIMENTs, analyzing the data with 2sample t test. The flash length was measured using a vernier caliper.

1. Depth of air groove

The depth of the air groove determines the size of a channel for forming flash when the foaming raw material overflows the die, and the channel is too large, so that the foaming raw material can overflow a large amount of raw material through the air groove, and the product quality is abnormal; the passage is too small, the air displacement of the die is insufficient, and the product can be lack of materials. Therefore, comparative experiments were performed using a 0.5mm gas cell and a 1mm gas cell, respectively. Each of 30 car seat back molded products was produced, and the flash length (mm) of the product was measured, and the results are shown in table 1 and fig. 5.

TABLE 1 influence of gas groove depth on product flash length

As can be seen from Table 1 and FIG. 5, the gas groove depth has a significant effect on the product flash length. The flash length can be obviously reduced when the depth of the air groove is 0.5 mm.

2. Air bag pressure

The pressure in the mold pushes the foaming material to flow everywhere to release the pressure. Because the parting surface of the mould is a weak point, the binding force of the upper mould and the lower mould to the raw material is weak, the foaming raw material can escape, and flash is generated. 30 pieces of molded products of the automobile seat back were produced by using air bag pressures of 1.5bar and 3bar, respectively, and the flash lengths (mm) of the products were measured, and the results are shown in Table 2 and FIG. 6.

TABLE 2 influence of air bag pressure on product flash length

As can be seen from table 2 and fig. 6, the bag pressure has a significant effect on the length of the product flash. A bag pressure of 3bar enables a significant reduction in the flash length.

3. Parting surface sealing mode

The flash sending depth is influenced by the gap of the parting surface of the die, when the upper die and the lower die are in clearance fit, the foaming raw material is easy to flow out from the gap, when the die is in interference fit, the fit part between the upper die and the lower die is easy to bend and deform, the foaming raw material is filled between the cavity of the parting surface and the highest point of the bend part to form the flash, and the flash is higher in bending degree and higher in flash length. The parting surface soft sealing mode that the parting surface of the common aluminum material is in clearance fit and the parting surface of the upper die is provided with a U-shaped groove and the parting surface of the lower die is provided with an air groove and a sealing ring is filled in an accommodating space where the U-shaped groove and the air groove are matched is selected, 30 automobile seat back plate plastic part products are produced respectively, the flash length (mm) of the products is measured, and the results are shown in table 3 and fig. 7.

TABLE 3 influence of parting surface sealing mode on product flash length

As can be seen from table 3 and fig. 7, the parting plane sealing manner has a significant influence on the length of the product flash. The parting surface soft seal can obviously reduce the length of flash.

4. Design of DOE experiment

The DOE experiment is repeated for 4 times in a three-factor two-level mode on the selected factors, specific parameter settings are shown in table 4, and experimental results are shown in fig. 8-9.

Table 4 DOE experimental parameter settings

The results shown in fig. 8 were obtained by analyzing the influence of the DOE experiment on the degradation, and it is understood from the Pareto chart (fig. 8A) that only C (U-groove depth of the parting surface of the upper mold) has a significant influence on the variation. From the interaction graph (fig. 8C) in the DOE experiment, it is seen that there is no interaction between the factors, and from the main effect graph (fig. 8B), it is seen that the deviation is small when C (the U-groove depth of the parting surface of the upper mold) is taken to be 8.5 mm.

From the influence of the DOE experiment on the mean value, the result shown in fig. 9 is obtained, and from the Pareto chart (fig. 9A) of the normalization effect in the DOE experiment, it can be seen that A, B, C and BC both have significant influence on Yp (flash length at gas groove), with C (U-groove depth of upper mold parting plane) having the most significant influence; as can be seen from the interaction diagram (fig. 9C), the three factors have no interaction. It can be seen from the main effect diagram (fig. 9B) that the value of Yp (flash length at the gas groove) is the minimum when a (air bag pressure) is 3bar, B (gas groove depth at the parting surface of the lower die) is 0.5mm, and C (U-shaped groove depth at the parting surface of the upper die) is 8.5 mm.

Through the optimization, aiming at the selection of the air bag pressure: the pressure of the air bag is preferably controlled to be 2.5 to 3 bar. However, the air bag pressure selection will be different due to different performances of different molds and foaming materials, and the influence of the air bag pressure on Yp (flash length at the air groove) is the least according to the data of the invention, so the invention does not limit the air bag pressure. And (3) selecting the depth of the gas groove of the parting surface: the depth of the air groove on the parting surface of the lower die is controlled to be about 0.5 mm. Selection of depth of the U-shaped groove: and (3) forming a U-shaped groove on the parting surface of the upper die of the die, embedding a sealing ring for soft sealing, and controlling the depth of the U-shaped groove to be 8.5 mm. By adopting the soft sealing mode of the invention, the improved scheme of the soft sealing of the mould with the K215 front leaning is transversely expanded to the upper scheme of K216, K218, K256, JCSB and D2UC at present, and the qualified rate of the flash is improved from 0% to 99%.

Application example

The common electric spark parting surface sealing mode and the soft sealing mode are adopted, the mould is foamed and molded under the same process condition, the maintenance frequency of the parting surface is compared, the influence of different parting surface sealing modes on the mould and a product is evaluated, and the specific result is shown in a figure 10 and a table 5.

TABLE 5 maintenance costs of molds for different sealing modes

As can be seen from FIG. 10, the product produced by the spark seal method has significant flash; and it can be seen by counting the maintenance conditions of 400 molds (table 5) that the soft sealing method of the invention can significantly reduce the maintenance frequency of the foam molding mold, prolong the service life, and reduce the manual maintenance time, and further count the statistical data of the material cost, labor cost, maintenance time, etc. of the different sealing methods, and the soft sealing maintenance cost adopted by each mold is 628.8 yuan lower than that of the electric spark every year, greatly reducing the production cost, and having higher economic benefit.

Claims

1. The utility model provides a parting surface (4) soft sealed foaming forming die, its characterized in that, includes the mould that forms after last mould (1) and lower mould (2) fold, be equipped with die cavity (3) and die joint (4) of treating processing in the mould, die joint (4) are including last mould (1) die joint (4) and lower mould (2) die joint (4), one of them die joint (4) are equipped with U type groove (5), another be equipped with air groove (6) on die joint (4), air groove (6) with embedded hollow sealing washer (7) that are equipped with of accommodation space that U type groove (5) closed the formation, the volume of sealing washer (7) is greater than the volume of accommodation space.

2. Parting surface (4) soft sealing foaming mold according to claim 1, characterized in that the predetermined distance of the U-shaped groove (5) from the boundary line between the parting surface (4) and the cavity (3) is 3-5 mm.

3. Parting surface (4) soft-sealing foaming mold according to claim 1 or 2, characterized in that the sealing ring (7) is provided with a chamfer (8) on the side facing the air groove (6).

4. Parting surface (4) soft sealing foaming mold according to claim 1, characterized in that the air groove (6) has a groove width of 9 to 11mm and a groove depth of 0.3 to 0.7 mm.

5. Parting surface (4) soft sealing foaming molding die as claimed in claim 4, characterized in that the air groove (6) has a groove width of 10mm and a groove depth of 0.5 mm.

6. Parting surface (4) soft sealing foaming molding die of claim 1, wherein the sealing ring (7) comprises a trapezoid section (71) and a circular arc section (72) with smooth transition, the small diameter end of the trapezoid section (71) is connected with the circular arc section (72) and the length of the small diameter end is the same as the diameter of the circular arc;

the length of the small-diameter end of the trapezoid section (71) is 8-10 mm, the length of the large-diameter end of the trapezoid section (71) is 9-11 mm, the height of the trapezoid section (71) is 4-6 mm, and the diameter of the circular arc section (72) is 8-10 mm.

7. Parting surface (4) soft sealing foaming mold according to claim 6, characterized in that the length of the small diameter end of the trapezoid section (71) is 9mm and the length of the large diameter end is 10mm, the height of the trapezoid section (71) is 5mm, the arc diameter of the arc section (72) is 9mm, and the height of the seal ring (7) is 9.5 mm.

8. Parting surface (4) soft sealing foaming molding die according to claim 1, wherein the U-shaped groove (5) comprises a smoothly transitional conical section (51) and an arc section (52), the large diameter end of the conical section (51) is connected with the arc section (52) and the length of the large diameter end is the same as the diameter of the arc;

the length of the small-diameter end and the length of the large-diameter end of the conical section (51) are 8-9 mm and 8-10 mm respectively, the height of the conical section (51) is 3-5 mm, and the diameter of the arc section (52) is 8-10 mm.

9. Parting surface (4) soft sealing foaming molding die according to claim 8, characterized in that the length of the small diameter end of the conical section (51) is 8.6mm and the length of the large diameter end is 9mm, the height of the conical section (51) is 4mm, the arc diameter of the arc section (52) is 4.5mm, and the groove depth of the U-shaped groove (5) is 8.5 mm.

10. Parting surface (4) soft sealing foaming molding die of claim 1, characterized in that the sealing ring (7) is 0.3-1.5 mm higher than the U-shaped groove (5).