Drawing die

Abstract

The utility model discloses a drawing die. The drawing die comprises an upper die, a lower die, a blank holder assembly, a floating material pressing part and a nitrogen spring assembly, the blank holder assembly is located between the upper die and the lower die, and a through part is formed on the blank holder assembly; the floating material pressing part is arranged in the through part and is in sliding connection with the blank holder assembly; the lower portion of the nitrogen spring assembly abuts against the lower die, and the upper portion of the nitrogen spring assembly is connected with the bottom end of the floating pressing part. The nitrogen spring assembly is configured to drive the floating material pressing part to move upwards when the drawing die is closed so as to press a workpiece located between the upper die and the blank holder assembly; and the drawing die opens the nitrogen spring assembly to drive the floating material pressing part to move downwards, so that a gap is formed between the floating material pressing part and the workpiece. The drawing die is closed, the nitrogen spring assembly drives the floating material pressing part to be tightly attached to the workpiece, and the drawing quality can be improved. When the drawing die is opened, the nitrogen spring assembly drives the floating material pressing part to move downwards, so that a gap is formed between the floating material pressing part and the workpiece, and a clamping space is provided for the manipulator.

Description

Technical Field

[0001] The utility model relates to the technical field of molds, and particularly relates to a drawing die. Background Art

[0002] A drawing die is a process equipment that, under the action of a press, through the combined action of an upper die, a lower die and a blank holder, stretches a flat blank into a workpiece with a certain spatial shape through plastic deformation. According to the different types of equipment used, it can be divided into a single-action drawing die and a double-action drawing die. The single-action drawing die uses the air cushion mechanism of the machine tool for blank holding and forms with a punch and a die. The double-action drawing die uses the external slide block mechanism of the machine tool for blank holding and forms with a punch and a die. In the process of automated production, a manipulator is an important component. The manipulator works through a control system and its own power, has multiple joints and multiple degrees of freedom, and can replace human labor in industrial production. In the process of drawing, the blank holder of the drawing die needs to avoid the manipulator gripper, resulting in the material at the gripping part being out of control. Specifically, during drawing, the material flow direction and speed around the part to be gripped by the manipulator are inconsistent, which may cause the material to deform and curl, making it impossible for the manipulator to grip and resulting in automation failure. Summary of the Utility Model

[0003] In view of the problems pointed out in the background art, in some embodiments, a drawing die is provided to solve the problems in the prior art that during drawing, the material flow direction and speed around the part to be gripped by the manipulator are inconsistent, which may cause the material to deform and curl, making it impossible for the manipulator to grip and resulting in automation failure, etc.

[0004] To achieve the above utility model purpose, the present utility model adopts the following technical solutions:

[0005] In some embodiments, a drawing die is provided, including:

[0006] An upper die;

[0007] A lower die;

[0008] A blank holder assembly, which is located between the upper die and the lower die and has a through hole formed thereon;

[0009] A floating blank holding part, which is arranged in the through hole and is slidably connected with the blank holder assembly;

[0010] A nitrogen spring assembly, the lower part of which abuts against the lower die, and the upper part of which is connected to the bottom end of the floating blank holding part;

[0011] Wherein, the nitrogen spring assembly is configured such that when the drawing die is closed, the nitrogen spring assembly drives the floating pressure pad portion to move upward to press the workpiece located between the upper die and the blank holder assembly; when the drawing die is opened, the nitrogen spring assembly drives the floating pressure pad portion to move downward so as to form a gap between the floating pressure pad portion and the workpiece.

[0012] In some embodiments of the present application, the blank holder assembly includes:

[0013] A backing plate, through holes are formed in the backing plate;

[0014] A blank holder, the blank holder is fixed above the backing plate, an opening groove is formed in the blank holder, the position of the opening groove corresponds to that of the through hole, and the through hole and the opening groove together form the through portion.

[0015] In some embodiments of the present application, when the drawing die is closed, the top surface of the floating pressure pad portion and the upper surface of the blank holder form a flat surface.

[0016] In some embodiments of the present application, the nitrogen spring assembly includes:

[0017] A nitrogen spring, the upper part of the nitrogen spring is embedded in the floating pressure pad portion, and the top of the nitrogen spring is fixedly connected to the floating pressure pad portion.

[0018] In some embodiments of the present application, a first mounting hole is formed in the floating pressure pad portion, and a bottom lock screw passes through the first mounting hole to threadedly connect the nitrogen spring to the floating pressure pad portion.

[0019] In some embodiments of the present application, the nitrogen spring assembly further includes:

[0020] An elastic member, the elastic member is sleeved outside the floating pressure pad portion;

[0021] A baffle plate, the baffle plate is fixedly connected to the bottom end of the floating pressure pad portion. When the drawing die is closed, the elastic member elastically abuts between the blank holder assembly and the baffle plate. When the drawing die is opened, the elastic member drives the floating pressure pad portion to move downward.

[0022] In some embodiments of the present application, the drawing die further includes:

[0023] A guiding portion, the guiding portion is fixedly arranged below the blank holder assembly, a guiding hole is formed in the guiding portion, the floating pressure pad portion passes through the guiding hole, and the elastic member is located between the guiding portion and the baffle plate.

[0024] In some embodiments of the present application, the elastic member includes a spring.

[0025] In some embodiments of the present application, a second mounting hole is formed on the lower die, a nitrogen spring seat is embedded in the second mounting hole, the nitrogen spring seat has a cylindrical structure, and the lower part of the nitrogen spring abuts against the nitrogen spring seat.

[0026] In some embodiments, a drawing die is provided, including:

[0027] An upper die;

[0028] A lower die;

[0029] A blank holder assembly, which is located between the upper die and the lower die and has a through portion formed thereon;

[0030] A floating blank holding portion, which is disposed in the through portion and is slidably connected to the blank holder assembly;

[0031] A nitrogen spring assembly, the lower part of which abuts against the lower die and the upper part of which is connected to the bottom end of the floating blank holding portion;

[0032] Wherein, the nitrogen spring assembly is configured to drive the floating blank holding portion to reciprocate between a first position where the floating blank holding portion presses a workpiece located between the upper die and the blank holder assembly and a second position where a gap is formed between the floating blank holding portion and the workpiece.

[0033] The above embodiments have the following advantages or beneficial effects: The drawing die is provided with an upper die, a lower die, a blank holder assembly, a floating blank holding portion and a nitrogen spring assembly. The blank holder assembly is located between the upper die and the lower die, a through portion is formed on the blank holder assembly, the floating blank holding portion is disposed in the through portion and is slidably connected to the blank holder assembly, the lower part of the nitrogen spring assembly abuts against the lower die, and the upper part of the nitrogen spring assembly is connected to the bottom end of the floating blank holding portion. When the drawing die is closed, the nitrogen spring assembly drives the floating blank holding portion to move upward to press the workpiece. The nitrogen spring assembly can provide sufficient pressure to make the floating blank holding portion closely fit the workpiece, and the workpiece flows under control and remains flat throughout the process without wrinkling and curling, which is beneficial to improving the drawing quality; when the drawing die is opened, the nitrogen spring assembly drives the floating blank holding portion to move downward to form a gap between the floating blank holding portion and the workpiece, providing a clamping space for the manipulator and facilitating the manipulator to pick and place the workpiece. The structure of the drawing die of the present application is simple, easy to install, low in manufacturing cost, and safe and reliable. Description of the Drawings

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 One of the structural schematic diagrams of an embodiment of the drawing die provided by the present invention;

[0036] Figure 2 For Figure 1 The partial enlarged view of area A in

[0037] Figure 3 The structural schematic diagram of the blank holder assembly provided by the present invention;

[0038] Figure 4 The exploded view of the blank holder assembly provided by the present invention;

[0039] Figure 5 Another structural schematic diagram of an embodiment of the drawing die provided by the present invention;

[0040] Figure 6 Another structural schematic diagram of an embodiment of the drawing die provided by the present invention;

[0041] Figure 7 For Figure 6 The sectional view along the B-B direction;

[0042] Figure 8 Another structural schematic diagram of an embodiment of the drawing die provided by the present invention;

[0043] Figure 9 For Figure 8 The sectional view along the C-C direction;

[0044] Figure 10 The partial structural schematic diagram of the nitrogen spring assembly provided by the present invention.

[0045] Reference numerals:

[0046] 1. Upper die;

[0047] 2. Blank holder assembly; 21. Through portion; 22. Backing plate; 221. Through hole; 23. Blank holder; 231. Open slot;

[0048] 3. Floating pressure material part; 31. First mounting hole; 32. Bottom lock screw;

[0049] 4. Nitrogen spring assembly; 41. Nitrogen spring; 42. Elastic member; 43. Baffle plate;

[0050] 5. Lower die; 51. Second mounting hole; 52. Nitrogen spring seat;

[0051] 6. Guide part; 61. Guide hole;

[0052] 7. Workpiece. Detailed implementation manners

[0053] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0054] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application.

[0055] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "plurality" is two or more.

[0056] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0057] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may also include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is less than that of the second feature.

[0058] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0059] Drawing, also known as stretching, rolling, etc., refers to a mechanical processing technology that uses a mold to stamp a flat blank of a certain shape obtained after blanking into various open hollow parts or to reduce the diameter and increase the height of an open hollow blank, and can manufacture parts with extremely complex shapes. Therefore, the drawing process occupies an important position in the production processes of fields such as household appliances, automobiles, and electronics.

[0060] A drawing die is a processing tool for materials such as metals, plastics, and glass, and mainly changes the shape and size of raw materials through methods such as stretching and elongation.

[0061] Drawing dies are widely used in multiple industries. For example, in the automotive industry, they are mainly used for producing stamping parts such as body panels and structural parts; in the metallurgical industry, they are mainly used for the forming processing of metal materials. In the glass industry, they are mainly used for manufacturing products such as glass tubes and glass rods. In the plastic industry, they are mainly used for the forming of plastic products such as plastic tubes and plastic plates.

[0062] Drawing dies have high-precision manufacturing and assembly to ensure the forming accuracy and quality of workpieces. At the same time, the die material needs to have sufficient strength and stiffness to withstand the large deformation forces during the stretching process.

[0063] In addition, the structure of the drawing die is convenient for disassembly and maintenance to improve production efficiency and reduce downtime.

[0064] Combined Figures 1 to 10 As shown, in some embodiments, a drawing die is provided. The drawing die includes an upper die 1, a lower die 5, a blank holder assembly 2, a floating pressure pad 3, and a nitrogen spring assembly 4.

[0065] The upper die 1 has a groove-shaped structure, and its shape matches the workpiece 7 to be processed.

[0066] Combined Figure 1 As shown, the blank holder assembly 2 is located between the upper die 1 and the lower die 5. During the stretching process, in order to prevent the edge part of the workpiece 7 from becoming unstable and wrinkling, the blank holder assembly 2 is provided between the upper die 1 and the lower die 5. A through hole 21 is formed in the blank holder assembly 2, and the through hole 21 has a hole-shaped structure.

[0067] The longitudinal section of the floating pressure pad 3 is T-shaped, and it is arranged in the through hole 21 and is slidably connected to the blank holder assembly 2.

[0068] The lower part of the nitrogen spring assembly 4 abuts against the lower die 5, and the upper part of the nitrogen spring assembly 4 is connected to the bottom end of the floating pressure pad 3. In this way, the floating pressure pad 3 can reciprocate relative to the blank holder assembly 2 driven by the nitrogen spring assembly 4.

[0069] Among them, the nitrogen spring assembly 4 is configured such that when the drawing die is closed, the nitrogen spring assembly 4 drives the floating pressure pad 3 to move upward. That is, after the floating pressure pad 3 moves toward the workpiece 7 to reach a certain position, the floating pressure pad 3 presses the workpiece 7 located between the upper die 1 and the blank holder assembly 2.

[0070] When the drawing die is opened, the nitrogen spring assembly 4 drives the floating pressure pad 3 to move downward. That is, the floating pressure pad 3 moves away from the workpiece 7 to form a gap between the floating pressure pad 3 and the workpiece 7.

[0071] Specifically, when the drawing die is closed, the nitrogen spring assembly 4 drives the floating pressure pad 3 to move upward to press the workpiece 7. The nitrogen spring assembly 4 can provide sufficient pressure to make the floating pressure pad 3 closely fit the workpiece 7. The workpiece 7 flows under control and remains flat throughout the process without wrinkling and curling, which is beneficial to improving the drawing quality.

[0072] When the drawing die is opened, the nitrogen spring assembly 4 drives the floating pressure pad 3 to move downward to form a gap between the floating pressure pad 3 and the workpiece 7, providing a clamping space for the manipulator and facilitating the manipulator to pick and place the workpiece 7. The structure of the drawing die in this application is simple, easy to install, low in manufacturing cost, and safe and reliable.

[0073] In some embodiments of this application, the blank holder assembly 2 includes a backing plate 22 and a blank holder 23.

[0074] A through hole 221 is formed in the backing plate 22, and the bottom end of the floating blank holder 3 passes through the through hole 221.

[0075] Combined Figure 2 、 Figure 3 and Figure 4 As shown in FIGS., the blank holder 23 is detachably fixed above the backing plate 22 by fasteners such as screws. An opening groove 231 is formed in the blank holder 23. The opening groove 231 is located directly above the through hole 221, and the positions of the opening groove 231 and the through hole 221 correspond to each other. The through hole 221 and the opening groove 231 communicate with each other to jointly form a through portion 21.

[0076] Specifically, by providing the opening groove 231 on the blank holder 23, during the drawing process, a part of the edge of the workpiece 7 is located above the opening groove 231. When the drawing die is opened, this part of the edge of the workpiece 7 will be in a suspended state. The opening groove 231 provides a basic space for the manipulator to clamp the workpiece 7, facilitating the manipulator to clamp the workpiece 7 and being beneficial to improving the degree of automation.

[0077] It should be noted that the opening groove 231 is adapted to the upper end of the floating blank holder 3, and the inner diameter of the opening groove 231 is larger than the inner diameter of the through hole 221. In this way, the edge of the through hole 221 forms a blocking effect on the upper end of the floating blank holder 3, preventing the floating blank holder 3 from passing through the through hole 221 and sliding off the backing plate 22.

[0078] In some embodiments of the present application, when the drawing die is closed, the top surface of the floating blank holder 3 and the upper surface of the blank holder 23 form a flat surface.

[0079] Specifically, when the drawing die is closed, the top surface of the floating blank holder 3 and the upper surface of the blank holder 23 form a flat surface. The floating blank holder 3 fills the vacancy formed at the opening groove 231, and can apply pressure to the workpiece 7, which is beneficial to maintaining the flatness of the workpiece 7.

[0080] In some embodiments of the present application, the nitrogen spring assembly 4 includes a nitrogen spring 41.

[0081] The nitrogen spring 41 is also called the die nitrogen spring 41 or nitrogen cylinder. It is a new type of elastic component with high-pressure nitrogen as the working medium, having the advantages of small volume, large elastic force, long stroke, stable operation, precise manufacturing, long service life (one million times), gentle elastic force curve, and no need for preloading, etc. It can perform tasks that are difficult for conventional elastic components such as metal springs, rubber, and air cushions, simplifies die design and manufacturing, facilitates die installation and adjustment, extends the service life of the die, and ensures the stability of product quality. Participating in the work as a part of the die, it can easily achieve constant pressure and delay action in the system, and is an ideal elastic component of a new generation with flexible performance.

[0082] The nitrogen gas spring 41 seals high-pressure nitrogen gas (10 - 15 Mpa) in a high-pressure container, compresses the nitrogen gas by an external force, and when the external force is removed, obtains a certain spring pressure by the expansion of the high-pressure nitrogen gas.

[0083] The bottom of the floating blank holding part 3 is recessed upward to form a cavity, the upper part of the nitrogen gas spring 41 is embedded in the cavity of the floating blank holding part 3, and the top of the nitrogen gas spring 41 is fixedly connected to the floating blank holding part 3. Therefore, in this application, the spring pressure of the nitrogen gas spring 41 directly acts on the floating blank holding part 3.

[0084] In some embodiments of this application, a first mounting hole 31 is formed on the top surface of the floating blank holding part 3. The first mounting hole 31 is in the form of a stepped hole, and the bottom lock screw 32 passes through the first mounting hole 31 to threadedly connect the nitrogen gas spring 41 and the floating blank holding part 3.

[0085] Specifically, by threadedly connecting the floating blank holding part 3 and the nitrogen gas spring 41 through the bottom lock screw 32, the floating blank holding part 3 and the nitrogen gas spring 41 form a linkage. When the nitrogen gas spring 41 is pressed by an external force, it can drive the floating blank holding part 3 to move towards the lower die 5.

[0086] In some embodiments of this application, as shown in Figure 7 the nitrogen gas spring assembly 4 further includes an elastic member 42 and a baffle 43.

[0087] The elastic member 42 is sleeved on the outside of the floating blank holding part 3, which can simplify the structure of the drawing die, save space, and facilitate assembly. Of course, theoretically, the elastic member 42 can also be arranged at other positions between the backing plate 22 and the lower die 5.

[0088] The baffle 43 is fixedly connected to the bottom end of the floating blank holding part 3 by fasteners or welding. The baffle 43 is disposed around the outside of the nitrogen gas spring 41. As shown in Figure 8 and Figure 9 when the drawing die is closed, the elastic member 42 is squeezed, and the elastic member 42 elastically abuts between the backing plate 22 and the baffle 43. As shown in Figure 6 and Figure 7 when the drawing die is opened, the spring pressure of the nitrogen gas spring 41 is released. At this time, the compressed elastic member 42 has an elastic restoring force to drive the floating blank holding part 3 to move downward.

[0089] Specifically, by providing the elastic member 42 and the baffle 43, when the drawing die is opened, when the nitrogen spring 41 is no longer subjected to an external force and releases pressure, the elastic member 42 has an elastic restoring force and applies a force towards the baffle 43, causing the baffle 43 to move away from the backing plate 22. Since the baffle 43 is connected to the floating blank holding part 3, the floating blank holding part 3 is caused to move away from the workpiece 7, creating a gap between the top end of the floating blank holding part 3 and the workpiece 7 for the manipulator to pick up the workpiece 7.

[0090] The nitrogen spring assembly 4 of the present application has the advantages of simple structure, low manufacturing cost, and safety and reliability.

[0091] In some embodiments of the present application, in combination with Figure 5 and Figure 6 as shown, the drawing die further includes a guiding part 6.

[0092] The guiding part 6 has a block-like structure and can be square or cylindrical. The guiding part 6 is fixedly provided below the backing plate 22 by means of fasteners or welding. A guiding hole 61 is formed on the guiding part 6. The guiding hole 61 communicates with the first mounting hole 31, and both the guiding hole 61 and the first mounting hole 31 are adapted to the floating blank holding part 3. The floating blank holding part 3 passes through the guiding hole 61, and the elastic member 42 is located between the guiding part 6 and the baffle 43.

[0093] Specifically, during the reciprocating movement of the floating blank holding part 3 along the through hole 21, the guiding part 6 plays a guiding role, which helps to prevent the nitrogen spring 41 from being subjected to an inclined force during operation, preventing the nitrogen spring 41 from failing or leaking air.

[0094] In some embodiments of the present application, the elastic member 42 includes a spring.

[0095] Specifically, the elastic member 42 can be a spring in the form of a round wire.

[0096] In some embodiments of the present application, in combination with Figure 7 and Figure 10 as shown, a second mounting hole 51 is formed on the lower die 5, and a nitrogen spring seat 52 is embedded in the second mounting hole 51. The nitrogen spring seat 52 has a cylindrical structure, and the lower part of the nitrogen spring 41 extends into the nitrogen spring seat 52 and abuts against the nitrogen spring seat 52.

[0097] Specifically, the size of the baffle 43 is slightly smaller than the inner size of the nitrogen spring seat 52. In this way, during the opening and closing of the drawing die, the baffle 43 can enter the nitrogen spring seat 52, which helps to reduce the distance between the lower die 5 and the backing plate 22 of the blank holder assembly 2 and improve the structural compactness of the drawing die.

[0098] In some embodiments, a drawing die is provided. The drawing die includes an upper die 1, a lower die 5, a blank holder assembly 2, a floating pressure pad 3, and a nitrogen spring assembly 4.

[0099] The blank holder assembly 2 is located between the upper die 1 and the lower die 5, and a through hole 21 is formed in the blank holder assembly 2.

[0100] The floating pressure pad 3 is disposed in the through hole 21 and is slidably connected to the blank holder assembly 2.

[0101] The lower part of the nitrogen spring assembly 4 abuts against the lower die 5, and the upper part of the nitrogen spring assembly 4 is connected to the bottom end of the floating pressure pad 3;

[0102] Wherein, the nitrogen spring assembly 4 is configured to drive the floating pressure pad 3 to reciprocate between a first position where the floating pressure pad 3 tightly presses the workpiece 7 located between the upper die 1 and the blank holder assembly 2 and a second position where a gap is formed between the floating pressure pad 3 and the workpiece 7.

[0103] In the first position, the floating pressure pad 3 is tightly pressed together with the workpiece 7, and in the second position, a gap is formed between the floating pressure pad 3 and the workpiece 7, facilitating the clamping of the workpiece 7 by a manipulator.

[0104] Exemplarily, the installation process of the floating pressure pad 3 and the nitrogen spring assembly 4 on the blank holder assembly 2 and the lower die 5 is as follows:

[0105] In the first step, align the guide hole 61 on the guide part 6 with the through hole 221 on the backing plate 22, and fix the guide part 6 below the backing plate 22 with screws;

[0106] In the second step, the floating pressure pad 3 sequentially passes through the opening slot 231, the through hole 221, and the guide hole 61 from top to bottom; then the elastic member 42 is sleeved on the outside of the floating pressure pad 3 from bottom to top;

[0107] In the third step, fasten the baffle 43 to the lower end of the floating pressure pad 3 with screws, so that the elastic member 42 is located between the guide part 6 and the baffle 43;

[0108] In the fourth step, the nitrogen spring 41 is snapped into the cavity at the bottom of the floating pressure pad 3 from bottom to top, and the nitrogen spring 41 is fixed to the floating pressure pad 3 with a bottom lock screw 32 passing through the first mounting hole 31;

[0109] In the fifth step, fix the nitrogen spring seat 52 in the second mounting hole 51 on the lower die 5, and adjust the height of the blank holder assembly 2 so that the bottom of the nitrogen spring 41 contacts the nitrogen spring seat 52.

[0110] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any one or more embodiments or examples in a suitable manner.

[0111] The above are only the specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A drawing die, characterized in that: include: upper mold; Lower mold; A blank holder assembly, which is located between the upper die and the lower die and has a through portion formed thereon; A floating material holding portion, which is disposed in the through portion and is slidably connected to the blank holding ring assembly; A nitrogen spring assembly, the lower portion of which abuts against the lower die, and the upper portion of which is connected to the bottom end of the floating pressing part; Wherein, the nitrogen spring assembly is configured as follows: when the drawing die is closed, the nitrogen spring assembly drives the floating pressing part upward to press the workpiece between the upper die and the blank holder assembly; when the drawing die is opened, the nitrogen spring assembly drives the floating pressing part downward to form a gap between the floating pressing part and the workpiece.

2. The drawing die according to claim 1, characterized in that: The blank holder assembly comprises: A backing plate, wherein a through hole is formed on the backing plate; A pressure ring is fixed above the backing plate, and an open groove is formed on the pressure ring. The open groove corresponds to the position of the through hole, and the through hole and the open groove together form the through portion.

3. The drawing die according to claim 2, characterized in that: When the drawing die is closed, the top surface of the floating holding portion and the upper surface of the blank holder form a flat surface.

4. The drawing die according to claim 1, characterized in that: The nitrogen spring assembly comprises: A nitrogen spring, the upper portion of which is embedded in the floating pressing portion, and the top of which is fixedly connected to the floating pressing portion.

5. The drawing die according to claim 4, characterized in that: A first mounting hole is formed on the floating pressing part, and a bottom locking screw passes through the first mounting hole to threadably connect the nitrogen spring to the floating pressing part.

6. The drawing die according to claim 4, characterized in that: The nitrogen spring assembly also includes: An elastic member, wherein the elastic member is sleeved on the outer side of the floating pressing portion; The baffle is fixedly connected to the bottom end of the floating pressing part. When the drawing die is closed, the elastic member elastically abuts between the pressure ring assembly and the baffle. When the drawing die is opened, the elastic member drives the floating pressing part downward.

7. The drawing die according to claim 6, characterized in that: The drawing die also includes: The guide part is fixedly arranged below the pressure ring assembly, a guide hole is formed on the guide part, the floating pressure part passes through the guide hole, and the elastic member is located between the guide part and the baffle.

8. The drawing die according to claim 6, characterized in that: The elastic member includes a spring.

9. The drawing die according to claim 1, characterized in that: A second mounting hole is formed on the lower die, a nitrogen spring seat is embedded in the second mounting hole, the nitrogen spring seat is a cylindrical structure, and the lower part of the nitrogen spring abuts against the nitrogen spring seat.

10. A drawing die, characterized in that: include: upper mold; Lower mold; A blank holder assembly, which is located between the upper die and the lower die and has a through portion formed thereon; A floating material holding portion, which is disposed in the through portion and is slidably connected to the blank holding ring assembly; A nitrogen spring assembly, the lower portion of which abuts against the lower die, and the upper portion of which is connected to the bottom end of the floating pressing part; The nitrogen spring assembly is configured to drive the floating press part to reciprocate between a first position for pressing a workpiece between the upper die and the blank holder assembly and a second position for driving a gap between the floating press part and the workpiece.

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