Die-casting die with punch convenient to replace

Abstract

The utility model relates to the technical field of die-casting dies, in particular to a die-casting die with a punch convenient to replace, which is characterized in that upper die mounting holes are respectively arranged on two sides of a pressure plate bottom plate, a pressure plate connecting column is fixedly arranged on the lower surface of an upper die, and a pressure plate connecting hole is arranged on the pressure plate connecting column. Side pins are arranged in the upper die mounting holes and the material pressing plate connecting holes in a penetrating manner so as to fixedly connect the material pressing plate bottom plate and the material pressing plate connecting columns together, and set screws are arranged in the upper die mounting holes in a threaded connection manner and abut against the outer sides of the side pins; therefore, the pressure plate can be quickly separated from the upper die by disassembling the set screw and inserting and pulling the side pin, namely, the punch can be quickly separated from the pressure plate in production, and the punch is exposed along with the rising of the upper die so as to be convenient to replace, so that the service life of the die-casting die is prolonged, and the production efficiency of the die-casting die is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of die-casting molds, in particular to a die-casting mold with convenient punch replacement. Background Art

[0002] With the trend of lightweight automobiles, high-pressure aluminum alloy structural castings are widely used in key parts of automobiles. Casting products need to be processed with several high-precision holes of special shapes. In order to save costs and improve production efficiency, casting products can be punched and formed with multiple high-precision holes at one time while trimming and shaping, replacing secondary CNC machining and laser cutting steps to achieve the purpose of reducing production costs.

[0003] Automobile chassis structural parts refer to the load-bearing or force-bearing parts in the automobile, which are closely related to the safety of the automobile body and chassis parts. Chassis structural parts are connected with other structural parts to form a high-strength frame that is resistant to deformation. Such structural parts usually have the characteristics of large size, thin wall, and complex structure. Since the reliable safety of the automobile must be ensured during driving, high mechanical properties are required for automobile structural parts. Toughness-related structural parts generally require tensile strength>180MPa and elongation>10%; in order to obtain high performance, such structural parts are mostly produced by high vacuum die-casting process. In order to achieve lean production, some of the forming holes of the casting are subjected to trimming die punching process after die-casting. This trimming punching process can reduce or eliminate machining and laser cutting processes, saving production costs.

[0004] The design of trimming and punching structure in the prior art: the punch end face of the punch and die chipping structure of the trimming die is a plane, and the punch is installed on the upper die seat. Under the action of the press, the upper die presses the material through the pressure plate. When the material is pressed by the pressure plate in the closed die state, the punch moves downward smoothly through the die to perform the punching action; when the upper die returns, the upper slider of the press opens the die, and the punch returns to complete the punching. In the actual production process, the punch is prone to chipping, and there may be a gap between the punch and the die sleeve that is too large or too small, resulting in wear or chipping of the punch. In addition, the chipping of the punch and the trimming knife is analyzed: the force process of the punch is: in the process of the punch and die starting to bite, the die has a great impact, until the moment the punching is completed, the force disappears. The reciprocating force application and release makes the punch in a microscopic state of micro-deformation fatigue, generating internal stress inside the punch. With the increase of internal stress, stress concentration points are generated, causing local plastic deformation, local dislocation and slip, and forming crack sources under the action of reciprocating external forces. The crack sources gradually expand until the punch finally breaks. In addition, through the analysis of the force conditions of the punch, it is found that in the whole process before the punch is completely punched out, the force state is unbalanced and the blade is broken, and the punch spare parts need to be replaced. The blade is broken and the excess waste of the product cannot be cut. When the strength of the punch and the trimming blade itself cannot offset itself, the punch will break and break. However, the punch can only be replaced offline for die-casting molds, which is time-consuming and labor-intensive, thereby reducing production efficiency. Therefore, how to quickly replace the punch during online production has become a technical problem that technicians in this field need to solve urgently. Utility Model Content

[0005] In view of the above-mentioned problems, the utility model provides a die-casting mold with convenient punch replacement, so as to solve the problem in the prior art that the die-casting mold cannot quickly replace the punch during the online production process and can only be replaced offline, which is time-consuming and labor-intensive.

[0006] The utility model solves the above technical problems through the following technical solutions:

[0007] A die-casting die for convenient punch replacement, comprising an upper die, a lower die, a punch, a pressing plate, a side pin and a set screw;

[0008] The upper die is arranged on the lower die, the pressing plate comprises a pressing plate bottom plate and a pressing plate insert arranged on the pressing plate bottom plate, upper die mounting holes are respectively opened on both sides of the pressing plate bottom plate, and the upper die mounting holes have internal threads adapted to the set screws;

[0009] A blank pressing plate connecting column is fixedly arranged on the lower surface of the upper die, a blank pressing plate connecting hole is opened on the blank pressing plate connecting column, and operation holes are respectively opened on both sides of the upper die corresponding to the blank pressing plate connecting holes;

[0010] The punch is detachably fixed to the lower surface of the upper die and penetrates the press plate;

[0011] The side pin is passed through the upper mold mounting hole and the pressure plate connecting hole to fix the pressure plate bottom plate and the pressure plate connecting column together, and the stop screw is threadedly connected to the upper mold mounting hole, and the stop screw abuts against the outer side of the side pin.

[0012] In some of the embodiments, guide sleeves are disposed at the four bottom corners of the upper die, and guide pillars matched with the guide sleeves are disposed at the four top corners of the lower die.

[0013] In some of the embodiments, the guide sleeve is made of beryllium copper.

[0014] In some of the embodiments, the diameters of the upper die mounting hole and the pressure plate connecting hole are both 18 to 22 mm.

[0015] In some of the embodiments, the coaxiality tolerance of the upper die mounting hole and the pressure plate connecting hole is less than 0.02 mm.

[0016] In some embodiments, the diameter of the operation hole is 100 mm to 200 mm.

[0017] In some embodiments, the punch is fixed to the lower surface of the upper die by screws.

[0018] In some of the embodiments, the die-casting mold is a die-casting mold of an automobile chassis structure.

[0019] The above utility model has at least one of the following advantages or beneficial effects:

[0020] The utility model provides a die-casting mold for convenient replacement of punches, wherein upper mold mounting holes are respectively opened on both sides of a pressure plate bottom plate, a pressure plate connecting column is fixedly arranged on the lower surface of the upper mold, and a pressure plate connecting hole is opened on the pressure plate connecting column, and a side pin is arranged to penetrate into the upper mold mounting hole and the pressure plate connecting hole to fix the pressure plate bottom plate and the pressure plate connecting column together, and a stop screw is arranged to be threadedly connected in the upper mold mounting hole, and the stop screw abuts against the outer side of the side pin, so that the pressure plate can be quickly separated from the upper mold by removing the stop screw and inserting and pulling out the side pin, that is, the punch and the pressure plate can be quickly separated in production, and then the punch is exposed as the upper mold rises for easy replacement, thereby increasing the service life of the die-casting mold and improving the production efficiency of the die-casting mold; and by arranging a guide column and a guide sleeve to guide, the hole size deviation and product deformation caused by the offset of the punch when punching the die-casting mold can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention and its features, appearance and advantages will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not drawn to scale, and the emphasis is on illustrating the subject matter of the present invention.

[0022] Figure 1 It is an exploded schematic diagram of an upper die and a material holding bottom plate in a die-casting die for convenient replacement of a punch in an embodiment of the utility model;

[0023] Figure 2 It is a schematic diagram of the installation of the upper die and the material pressing bottom plate in the die-casting die for convenient replacement of the punch in the embodiment of the utility model;

[0024] Among them, 1 is the upper mold; 11 is the operating hole; 12 is the pressure plate connecting column; 121 is the pressure plate connecting hole; 13 is the guide sleeve; 2 is the pressure plate; 21 is the pressure plate bottom plate; 211 is the upper mold mounting hole; 22 is the pressure plate insert; 3 is the side pin; 4 is the stop screw. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0026] like Figure 1 and 2As shown, the utility model discloses a die-casting mold for convenient replacement of punches, and the die-casting mold can be a die-casting mold for automobile chassis structure; specifically, the die-casting mold includes an upper mold 1, a lower mold (not shown in the figure), a punch (not shown in the figure), a pressure plate 2, a side pin 3 and a stop screw 4; the upper mold 1 is arranged on the lower mold, and the pressure plate 2 includes a pressure plate bottom plate 21 and a pressure plate insert 22 arranged on the pressure plate bottom plate 21, and upper mold mounting holes 211 are respectively opened on both sides of the pressure plate bottom plate 21, and the upper mold mounting holes 211 have internal threads compatible with the stop screws 4; a pressure plate connecting column 12 is fixedly arranged on the lower surface of the upper mold 1, and a pressure plate connecting hole 121 is opened on the pressure plate connecting column 12, and operation holes 11 are respectively opened on both sides of the upper mold 1 corresponding to the pressure plate connecting holes 121; the punch is detachably fixed to the upper mold 1 by screws The lower surface of the pressing plate 2 is penetrated and arranged on the lower surface of the pressing plate 2; the side pin 3 is penetrated in the upper mold mounting hole 211 and the pressing plate connecting hole 121 to fix the pressing plate bottom plate 21 and the pressing plate connecting column 12 together, and the stop screw 4 is threadedly connected to the upper mold mounting hole 211, and the stop screw 4 abuts against the outer side of the side pin 3; thereby, the pressing plate 2 and the upper mold 1 can be quickly separated by removing the stop screw 4 and pulling out the side pin 3 during production, and the pressing plate 2 can be left on the lower mold during the production process, and the punch rises with the upper mold 1, so that the punch can be exposed for easy replacement, and then the punch can be quickly replaced in online production, thereby reducing the offline time of the mold, and by adjusting and removing the damaged punch and blade insert, the product burrs are solved, the product quality is improved, the service life of the die-casting mold is increased, and the production efficiency of the die-casting mold is improved.

[0027] In this embodiment, the above-mentioned pressure plate insert 22 is separately fixed on the pressure plate bottom plate 21, and the above-mentioned pressure plate bottom plate 21 and the pressure plate connecting column 12 of the upper mold 1 are connected by a side pin 3, and the outer side of the side pin 3 is fastened with a set screw 4. During the production process, if the punch is damaged, worn, or chipped, the set screw 4 can be removed and the side pin 3 can be pulled out when the press is in the state of the mold being closed to the bottom, so that the pressure plate 2 can be separated from the upper mold, and the upper mold 1 can go up with the press, exposing the punch installation screws and can be directly disassembled, thereby saving the mold offline time.

[0028] In a preferred embodiment of the utility model, the four corners of the bottom of the upper die 1 are provided with guide sleeves 13, and the four corners of the top of the lower die are provided with guide pillars adapted to the guide sleeves 13, so as to solve the hole size deviation and product deformation caused by the offset of the punch when punching the punching die. Specifically, the blanking clearance of the punching die is (2.0%-10%)*t, where t is the thickness of the sheet. The guide pillar and the guide sleeve 13 are installed at the die frame with a matching tolerance set to H7 / r6. The lower die is provided with a die sleeve (not shown in the figure) adapted to the punch, and the matching tolerance between the die sleeve and the punch is set to H7 / h6. The punch hanger and the pressure plate 2 have an interference in the thickness direction of 0.04-0.06mm. The single-sided clearance between the punch and the die sleeve is 5%-7% of the product thickness, and the matching clearance is 2%-10%. In order to improve the matching accuracy of the punch and the die sleeve, the guide sleeve 13 is made of beryllium bronze. This is because beryllium bronze has good wear resistance, high processing accuracy, high temperature resistance, and is not easy to bite the guide column. In this way, the punch runs more accurately and more smoothly without offset.

[0029] In an embodiment of the utility model, the diameters of the upper mold mounting hole 211 and the pressure plate connecting hole 121 are both 18 to 22 mm (for example, 18 mm, 20 mm, 21 mm or 22 mm, etc.); and the coaxiality tolerance of the upper mold mounting hole 211 and the pressure plate connecting hole 121 is less than 0.02 mm; the diameter of the operating hole 11 is 100 mm to 200 mm (for example, 100 mm, 120 mm, 150 mm or 200 mm, etc.), so as to facilitate the operator to install and remove the side pin 3 and the stop screw 4 through the operating hole 11.

[0030] The gap between the punch and the die sleeve is controlled according to the thickness of the product to be punched. Usually, the single-side gap is about 6% of the product thickness. The current product thickness is 2.5 mm, and the single-side gap of the die sleeve is enlarged to 0.15 mm. The normal punching aluminum plate material matching gap is about 2%-10%.

[0031] Specifically, the design principle and design process of the above die-casting mold are as follows:

[0032] First of all, it is necessary to adjust the fixation between the pressure plate 2 and the upper mold 1, how to change the disassembly from the front to the side, use the side pin 3 to penetrate, the principle is: the punch is installed on the upper mold 1, the pressure plate insert 22 is installed on the pressure plate base plate 21, the upper mold mounting hole 211 on the pressure plate base plate 21 and the pressure plate connecting hole 121 on the pressure plate connecting column 12 of the upper mold 1 correspond one to one, the positioning accuracy is ±0.05mm, and the hole diameter tolerance is ±0.02mm, so as to realize the quick plugging and unplugging and disassembly function of the pressure plate 2.

[0033] Then, the punch is designed to be detached from the pressure plate 2 during production, and the spare parts can be replaced in the open state, which is completely consistent with the product quality.

[0034] After that, the gap between the punch and the die sleeve is controlled, which should be selected according to the die structure, gap size, quality of the blanking parts and actual assembly conditions. The control and adjustment of the gap between the punch and the die sleeve can be done by light transmission method, feeler gauge method and gasket adjustment method. Finally, put the paper in for a test punch, observe the uniformity of the burrs around the cut paper, so as to judge whether the gap between the punch and the die sleeve is uniform, and then adjust the gap until the blanking burrs are uniform. And the gap between the bottom plate 21 of the press plate and the punch is adjusted to ±0.2mm, and then the upper die 1 and the bottom plate 21 of the press plate are inserted into the side pin 3 for positioning, and the stop screw 4 is installed to prevent it from falling off, so as to realize the rapid disassembly of the press plate 2.

[0035] In addition, in order to further verify the practical effect of the die-casting mold that is convenient for replacing the punch, preliminary tests and mass production verification were carried out on the optimized pressure plate bottom plate 21 to remove the stop screws 4 and the plug-in side pins. The punching quality of the produced castings was significantly improved, and there was no dent, tear or burr around the hole. In addition, due to unpredictable changes in the wall thickness of the die-casting, the punch and the blade insert were damaged, and the punch spare parts can be quickly replaced when the product cannot be cut.

[0036] The promotion of high vacuum die-casting technology has brought the die-casting process to a new level and promoted the technical development of die-casting molds. The die-casting mold has been verified by production practice, with reasonable structural design and stable and reliable operation; the die-casting parts punched by the mold do not need to be machined, which saves machining time, reduces production costs and improves production efficiency.

[0037] In summary, the utility model discloses a die-casting mold for convenient replacement of punches. The die-casting mold is designed according to the characteristics of the aluminum alloy structural parts of automobile chassis castings, so that the quality and size of the punching holes of the castings after punching are improved. The die-casting mold can quickly separate the punch from the pressing plate during production, so that the punch can be replaced online, which solves the problem of easy damage to the punch die sleeve, increases the service life of the mold, and improves the production efficiency of the mold; and solves the problem of changes in the product hole size due to equipment precision errors.

[0038] Those skilled in the art should understand that those skilled in the art can implement variations by combining the prior art and the above embodiments, which will not be described in detail here. Such variations do not affect the essential content of the present utility model, and will not be described in detail here.

[0039] The above describes the preferred embodiments of the utility model. It should be understood that the utility model is not limited to the above-mentioned specific implementation methods, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the utility model without departing from the scope of the technical solution of the utility model, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the utility model. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the utility model without departing from the content of the technical solution of the utility model still falls within the scope of protection of the technical solution of the utility model.

Claims

1. A die-casting die for convenient punch replacement, characterized in that: It includes an upper die, a lower die, a punch, a pressure plate, a side pin and a set screw; The upper die is arranged on the lower die, the pressing plate comprises a pressing plate bottom plate and a pressing plate insert arranged on the pressing plate bottom plate, upper die mounting holes are respectively opened on both sides of the pressing plate bottom plate, and the upper die mounting holes have internal threads adapted to the set screws; A blank pressing plate connecting column is fixedly arranged on the lower surface of the upper die, a blank pressing plate connecting hole is opened on the blank pressing plate connecting column, and operation holes are respectively opened on both sides of the upper die corresponding to the blank pressing plate connecting holes; The punch is detachably fixed to the lower surface of the upper die and penetrates the press plate; The side pin is passed through the upper mold mounting hole and the pressure plate connecting hole to fix the pressure plate bottom plate and the pressure plate connecting column together, and the stop screw is threadedly connected to the upper mold mounting hole, and the stop screw abuts against the outer side of the side pin.

2. The die-casting mold for convenient punch replacement according to claim 1, characterized in that: The four corners at the bottom of the upper die are all provided with guide sleeves, and the four corners at the top of the lower die are all provided with guide pillars matched with the guide sleeves.

3. The die-casting mold for convenient punch replacement according to claim 2, characterized in that: The guide sleeve is made of beryllium bronze.

4. The die-casting mold for convenient punch replacement according to claim 1, characterized in that: The diameters of the upper die mounting hole and the pressure plate connecting hole are both 18 to 22 mm.

5. The die-casting mold for convenient punch replacement according to claim 1, characterized in that: The coaxiality tolerance of the upper die mounting hole and the pressure plate connecting hole is less than 0.02 mm.

6. The die-casting mold for convenient punch replacement according to claim 1, characterized in that: The diameter of the operation hole is 100 mm to 200 mm.

7. The die-casting mold for convenient punch replacement according to claim 1, characterized in that: The punch is fixed to the lower surface of the upper die by screws.

8. The die-casting mold for convenient punch replacement according to claim 1, characterized in that: The die-casting mold is a die-casting mold for an automobile chassis structure.

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