阅读说明：本技术 一种大型深拉延模具 (Large deep drawing die ) 是由 张文波 万红武 寇兆阳 于 2020-04-16 设计创作，主要内容包括：本发明公开了一种大型深拉延模具,对原拉延模具的凹模口进行改造,铣去原有模具铸铁材料,在凹模口及压料部分铣开方槽,并在方槽内加装整体固定板,在整体固定板上镶合金钢淬火镶块并进行镀铬处理。本发明首次在大型拉延模具凹模口修复中采用镶镶块工艺,提高模具凹模口部位表面强度、硬度,降低摩擦系数。(The invention discloses a large deep drawing die, which is characterized in that a female die opening of an original drawing die is reformed, cast iron materials of the original die are milled, a square groove is milled at the female die opening and a pressing part, an integral fixing plate is additionally arranged in the square groove, and an alloy steel quenching insert is embedded in the integral fixing plate for chromium plating treatment. The invention adopts the insert block process in the die orifice repairing of the large drawing die for the first time, improves the surface strength and hardness of the die orifice part of the die, and reduces the friction coefficient.)

1. A large deep drawing die is characterized in that a square groove is milled at a female die opening of the drawing die, an integral fixing plate is additionally arranged in the square groove, and an alloy steel quenching insert is embedded in the integral fixing plate for chromium plating treatment.

2. The large deep drawing die according to claim 1, wherein the integral fixing plate is fixed in the milled square groove by a screw thread through a second screw hole and is positioned by a cylindrical pin.

3. A large deep-drawing die according to claim 2, wherein the alloy steel quenching insert and the integral holding plate are further positioned by rectangular blind keys.

4. The large deep drawing die according to claim 1, wherein the alloy steel quenching insert is fastened with the integral fixing plate through a screw hole in a screwing mode and is positioned through a cylindrical pin.

5. Large deep-drawing die according to claim 1, characterised in that the alloy steel quenching insert is in particular a Cr12MoV quenching insert.

6. A large deep-drawing die according to claim 1, characterised in that the alloy steel quench insert is in particular a copper alloy quench insert.

7. Large wall-ironing die according to claim 1, characterized in that the die opening is provided with reinforcement ribs for load-bearing purposes.

Technical Field

The invention relates to a large-scale deep drawing die for an automobile.

Background

The forming depth of a large drawing part of a truck reaches more than 150 mm due to the characteristics of a product, the forming depth is large, the plate material flows greatly, so that the stress of a die orifice of a die is large, the cold welding phenomenon is generated between the part of the die orifice with the largest stress of the die and the material of the part due to friction, and the cold welding phenomenon causes the die orifice of the die to be damaged by pulling to cause serious abrasion. Therefore, the finished piece is rough, cracked and has insufficient rigidity, the defective rate of the finished piece is extremely high, and the repair product rate is high. The traditional drawing die material (MoGr cast iron) has the defects that the strength, the hardness and the surface smoothness are difficult to meet the stress requirement of the deep drawing die, the welding repair method is difficult to repair a worn die orifice of the die, the online maintenance and polishing seriously affect the production efficiency, and the die is difficult to maintain normal production, so the die is faced with scrapping and copying. Such problems have long plagued host plants and mold manufacturers.

The large deep-drawing die body is worn for a long time, the traditional welding repair effect is poor, repeated welding vicious cycle is realized, some dies are difficult to maintain the basic production requirement, for example, a drawing die of an outer plate of a rear wall of a certain truck, the fillet of a die concave die opening is worn to R30 from the original design R15, and even the dimensional precision of a stamping part is influenced. Although the die can be repaired by adopting measures such as laser quenching, repair welding, integral chromium plating of the die and the like, the effect is not obvious, the cost of laser quenching and integral chromium plating of the die is huge, the cost of each chromium plating is 12-15 ten thousand yuan (according to different chromium plating areas), the service life is only maintained about 2 ten thousand, and the investment cost is huge.

The traditional material (MoCr cast iron) for the large-scale deep drawing die of the automobile has many advantages, but the defects are that the strength is low, the hardness is low, the weldability is poor, the drawing die cavity and the workpiece plate are subjected to cold friction welding to generate strain, and the traditional welding repair strength and hardness are not as good as those of the body material. Alloy steel (Cr12MoV) is high-strength steel, and an alloy steel insert block structure is rarely adopted in a material pressing part of a large deep drawing die, and a. the alloy steel has two problems that a, the friction coefficient is large, and the alloy steel is cold-welded with a workpiece plate after friction heat is generated, so that the plate is torn; b. the sheet material slides on the die opening insert, and the joints between the inserts scratch a workpiece.

Disclosure of Invention

The invention provides a large deep-drawing die, which is characterized in that an alloy steel chromium plating insert is embedded in a die notch, so that the surface strength and hardness of the die notch part of the die are improved, and the friction coefficient is reduced.

The purpose of the invention is realized by the following technical scheme:

a square groove is milled at a die opening of a drawing die, an integral fixing plate is additionally arranged in the square groove, and an alloy steel quenching insert is embedded in the integral fixing plate for chromium plating treatment.

Furthermore, the integral fixing plate is fixed in a milled square groove through a second screw hole in a screw connection mode and is positioned through a cylindrical pin.

Further, the alloy steel quenching insert and the integral fixing plate are positioned through a rectangular hidden key.

Furthermore, the alloy steel quenching insert is fastened with the integral fixing plate through a first screw hole in a threaded manner and is positioned through a cylindrical pin.

Further, the alloy steel quenching insert is specifically a Cr12MoV quenching insert.

Further, the alloy steel quenching insert is specifically a copper alloy quenching insert.

Furthermore, a reinforcing rib is arranged at the position of the female die opening and used for bearing under stress.

The invention has the following advantages:

the integral quenching insert of the alloy steel (Cr12MoV) has the characteristics of high strength, high hardness and the like, and the strength and the hardness are far higher than those of the traditional cast iron material (MoGr), so that the fatigue resistance and the wear resistance of the alloy steel are far better than those of cast iron. But the alloy steel has poor heat dissipation and is more serious in cold welding phenomenon caused by friction than cast iron materials, and the accumulated filings are easy to generate. The surface hardness, the smoothness and the wear resistance of the alloy steel insert after chromium plating all reach high levels, because the tensile strength of the alloy steel is far superior to that of cast iron materials, the problem that the chromium plating layer fails due to slag falling of a matrix after the chromium plating of the cast iron materials can not be generated during the chromium plating of the alloy steel, and the wear resistance of the alloy steel insert after the chromium plating treatment is close to that of TD treatment, but has the characteristic of no deformation after the treatment. The C12MoV quenching insert can be replaced by copper alloy, the effect is better, and the heat dissipation of the copper alloy is better.

According to the invention, through the transformation of the female die opening of the drawing die, the cast iron material of the original die is milled, the integral mounting plate is added, the alloy steel quenching insert is embedded on the integral mounting plate, and the chromium plating treatment is carried out, so that the strength and the hardness of the cast iron material are greatly improved to HRC60-62 compared with the original cast iron material. The scheme has the advantages that the test of multiple sets of dies such as the back wall outer plate, the top cover outer plate and the like is carried out, a good effect is obtained, the service life of the die is effectively prolonged, and the debugging period is shortened.

Drawings

FIG. 1 is an exploded isometric view of a large deep-drawing die according to the invention;

FIG. 2 is an isometric view of a large drawing die;

FIG. 3 is a rear plan view of the integral mounting plate of the present invention;

FIG. 4 is a top plan view of the alloy steel quench insert of the present invention;

FIG. 5 is an axonometric view of a square groove milled by the original drawing die;

figure 6 is an isometric view of a second mode of positioning of the present invention.

In the figure: 1-alloy steel quenching insert; 11-a screw hole; 12-cylindrical pin number one; 2-integral fixing plate; 21-second screw hole; 22-cylindrical pin number two; 31-reinforcing ribs; 32-square groove; 4-drawing the die; 41-female die orifice; 42-a pressing part; 5-rectangular dark key.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in figures 1 to 5, the large deep drawing die is characterized in that a die opening 41 of an original drawing die 4 is modified, cast iron materials of the original die are milled, a square groove 32 is milled in the die opening 41 and a pressing part 42, an integral fixing plate 2 is additionally arranged in the square groove 32, an alloy steel quenching insert is embedded in the integral fixing plate 2, chromium plating is carried out, and an insert block process is adopted in repairing of the die opening of the large drawing die for the first time.

The integral fixing plate 2 is fixed in the milled square groove 32 through a second screw hole 21 in a screw connection mode.

The die orifice 41 is provided with a reinforcing rib 31.

The alloy steel quenching insert is specifically a Cr12MoV quenching insert.

The C12MoV quenching insert can be replaced by copper alloy, the effect is better, and the heat dissipation of the copper alloy is better.

The alloy steel quenching insert is fastened with the integral fixing plate 2 through a first screw hole 11 in a threaded mode, the fastening direction is opposite to that of the first step, and fastening is performed reversely from the die body to ensure that no hole exists in the contact surface of the insert and the plate.

The integral fixing plate 2 and the square groove 32 realize fine positioning through the second cylindrical pin 22, and the position precision between the integral fixing plate and the square groove is ensured; the alloy steel quenching insert 1 and the integral fixing plate 2 are precisely positioned through the first cylindrical pin 12, so that the insert gap is ensured to be smaller than 0.02 mm, and the steel quenching insert is stable and reliable.

The alloy steel quenching insert 1 and the integral fixing plate 2 adopt a rectangular hidden key 5 and a first cylindrical pin 12 to be combined and positioned, and the advantages of ensuring enough anti-shearing force and ensuring positioning precision are achieved.

The following describes a specific implementation process of the technical scheme of the invention with reference to an embodiment:

(1) and (4) utilizing CATIA or other software to complete design on the three-dimensional entity of the die and determining the feasibility of the scheme. Milling a square groove 32 at a female die opening 41 and a pressing part 42 which are roughened and worn by an original drawing die 4 to ensure the installation flatness of the square groove, fixing the integral fixing plate 2 in the milled square groove 32 in a screw connection mode through a second screw hole 21, arranging a reinforcing rib 31 at the female die opening 41, bearing stress by the reinforcing rib 31 (reinforcing can be performed if the strength of the reinforcing rib is insufficient), installing an alloy steel (Cr12MoV) quenching insert group 1 on the integral fixing plate 2, and performing chromium plating treatment to replace the original casting material. The C12MoV quenching insert can be replaced by copper alloy, the effect is better, and the heat dissipation of the copper alloy is better.

(2) The fixing mode is as follows: firstly, fastening the integral fixing plate 2 with a milled square groove 32 plane through a second screw hole 21 in a screw connection mode; and secondly, fastening the Cr12MoV quenching insert 1 with the integral fixing plate 2 in a screw connection mode through a first screw hole 11, wherein the fastening direction is opposite to that of the first step, and fastening is performed reversely from the die body to ensure that no hole is formed on the contact surface of the insert and the plate.

(3) The positioning mode is as follows: the first positioning mode is that the integral fixing plate 2 and the milled square groove 32 realize fine positioning through the second cylindrical pin 22, and the position precision between the two is ensured; the Cr12MoV quenching insert and the integral fixing plate 2 are precisely positioned through a first cylindrical pin 12 (taking a group of inserts as an example), and the embedding clearance is ensured to be less than 0.02 mm, and the fixing device is stable and reliable. As shown in FIG. 6, in the second positioning mode, the Cr12MoV quenching insert and the integral fixing plate 2 adopt a rectangular hidden key 5 and a first cylindrical pin 12 for positioning and combining, so that the advantages of ensuring both sufficient shearing resistance and positioning accuracy are achieved.

(4) The qualified drawing die is debugged and produced through about 1000 running-in trials, the die can stably press qualified pieces, the alloy steel quenching insert 1 is subjected to chromium plating treatment, only the part which is in friction with the sheet material of the piece is plated, the assembly precision of the insert is kept, the smoothness of the insert after chromium plating is more than 0.8, the plating layer is 0.01-0.03 mm, the precision requirement of the material pressing surface of the drawing die is met, the friction coefficient is reduced, and the cold welding phenomenon is eliminated.