High-precision cylindrical grinder for lead frame

Abstract

The utility model discloses a high-precision cylindrical grinder for a lead frame. The high-precision cylindrical grinder comprises a lathe bed, and a power device, a grinding wheel assembly, a diamond grinding wheel repairing cutter, a cooling assembly, an air pump, a negative pressure pump, a dust removal box, a main shaft and a driven shaft which are arranged in the lathe bed. In the grinding wheel trimming process, compressed air generated by the air pump enters the air blowing cavity along the pipeline and the air pipe connector and then enters the blowing groove through the communicating groove, airflow is blown out after the flow speed is increased through the closing opening in the tail end of the blowing groove, and a complete annular air curtain is formed on the outer wall of a part located between the chuck and the ejector pin; high-speed moving sand particles generated during grinding wheel repairing can be effectively prevented from falling on the surface of a part, the product machining quality is improved, and then smooth production of a lead frame is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of lead frame production, in particular to a high-precision external cylindrical grinder for lead frames. Background Art

[0002] With the continuous development of the new generation of electronic information industry, the surface requirements for copper alloy strip used for high-end lead frame materials are getting higher and higher. It is required that there are no defects under a 40-fold tool microscope. Finish rolling is a key process for surface control in the production process of frame materials. The surface quality of the rolls required for finish rolling has a direct impact on the quality of the lead frame strip after rolling. And as the direct process for controlling the surface quality of the rolls, the grinding process of the rolls and the grinding wheel need to be improved technically as a whole.

[0003] Among them, the roll used in the finishing mill during finish rolling is required to have a roughness Ra < 0.08 and the surface of the roll cannot be damaged, so as to ensure that the surface of the strip after rolling meets the requirements of high-end lead frame materials. During the process of grinding the workpiece by the grinding wheel, due to the structure of the grinding wheel, the loose abrasive grains on the surface of the grinding wheel roll between the grinding wheel and the workpiece, which is easy to scratch the surface of the workpiece. The morphology is a linear shape like a water droplet. Because this linear defect is caused by the shedding of the abrasive grains of the grinding wheel, it is called abrasive grain mark. To solve this problem, there is a disclosed technology that uses a high-quality grinding wheel without pores, combined with a reasonable grinding wheel dressing process, to ensure the uniformity and surface flatness of the grinding wheel abrasive. A reasonable roll grinding process ensures the uniform shedding of abrasive grains during the grinding process of the grinding wheel, avoiding abrasive grain defects caused by uneven shedding.

[0004] However, in the prior art, for the high-precision external cylindrical grinding machine used for the roll in the production of lead frame rolling, when dressing the grinding wheel, only a vacuum cleaner is used to suck the dust at the dressing part of the grinding wheel. During dressing, there are still cases where abrasive grains fly out. After adhering to the product surface, it will still cause damage to the surface of the roll during the next finish grinding, which will affect the production progress of the lead frame. Therefore, it is necessary to propose an improvement to this problem. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the defects existing in the prior art, and to propose a high-precision external cylindrical grinder for lead frames.

[0006] To achieve the above object, the utility model adopts the following technical solutions: A high-precision external cylindrical grinder for a lead frame includes a bed body and a power device, a grinding wheel assembly, a diamond dressing wheel tool, a cooling assembly, an air pump, a negative pressure pump, a dust removal box, a main shaft and a driven shaft arranged inside the bed body. The main shaft and the driven shaft are arranged opposite to each other left and right, and a chuck and a center pin are respectively arranged at opposite ends. A blowing shell for forming an annular protective air curtain on the surface of a part during grinding wheel dressing is sleeved on the outer wall of the center pin, and a suction shell for sucking away the air flow blown out by the blowing shell is sleeved on the outer wall of the chuck. The blowing shell is composed of a first blowing shell, a second blowing shell and an inner jacket. The first blowing shell is sleeved on the outer wall of the center pin, the second blowing shell and the inner jacket are both threadedly connected to one end of the first blowing shell away from the driven shaft, and the second blowing shell is located outside the inner jacket. The suction shell is composed of a first suction shell and a second suction shell distributed left and right. Through holes running through left and right are arranged inside the blowing shell and the suction shell.

[0007] As a further description of the above technical solution:

[0008] The blowing shell and the suction shell are respectively sleeved on the outer walls of the center pin and the chuck through the through holes, and gaps are arranged between the inner side walls of the through holes inside the blowing shell and the outer wall of the center pin and between the inner side walls of the through holes inside the suction shell and the outer wall of the chuck.

[0009] As a further description of the above technical solution:

[0010] Fixing frames for fixing to the bed body are arranged on the outer walls of the second blowing shell and the second suction shell, and the blowing shell and the suction shell are respectively fixedly connected to the bed body through a group of fixing frames.

[0011] As a further description of the above technical solution:

[0012] Air pipe connectors are fixedly connected to the upper walls of the first blowing shell and the first suction shell. The air pipe connector on the upper wall of the first blowing shell is connected to the air pump through a pipeline, the air pipe connector on the upper wall of the first suction shell is connected to the dust removal box through a pipeline, and one end of the dust removal box away from the first suction shell is connected to the negative pressure pump.

[0013] As a further description of the above technical solution:

[0014] An annular suction cavity is arranged on the inner wall of the first suction shell and around the through hole. A suction groove is arranged at one end of the second suction shell away from the first suction shell. A plurality of suction holes for communicating the suction groove and the suction cavity are arranged on the inner wall of the second suction shell, and the plurality of suction holes are equally distributed in a circumferential manner with the axis of the suction shell as the center.

[0015] As a further description of the above technical solution:

[0016] An annular blowing cavity is arranged inside the first blowing shell and around the through hole. A blowing groove is formed between the inner side wall of the second blowing shell and the outer wall of the inner jacket. The end of the blowing groove far from the first blowing shell is provided with a constricted opening that contracts inward. One end of the first blowing shell facing the blowing groove is provided with a communication groove for communicating the blowing cavity and the blowing groove.

[0017] The utility model has the following beneficial effects:

[0018] Compared with the prior art, in the high-precision external cylindrical grinding of the lead frame, during the process of dressing the grinding wheel, the compressed air generated by the air pump enters the blowing cavity along the pipeline and the air pipe joint, then enters the blowing groove through the communication groove. After the air flow passes through the constricted opening at the end of the blowing groove to increase the flow rate, it is blown outwards, forming a complete annular air curtain on the outer wall of the part located between the chuck and the ejector pin. This can effectively prevent the high-speed moving abrasive grains generated during the grinding wheel dressing from falling on the surface of the part, improve the processing quality of the product, and then ensure the smooth production of the lead frame. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the overall structure of a high-precision external cylindrical grinding machine for a lead frame proposed by the utility model;

[0020] Figure 2 It is a partial cross-sectional view of the internal structure of the suction shell of a high-precision external cylindrical grinding machine for a lead frame proposed by the utility model;

[0021] Figure 3 It is a partial cross-sectional view of the internal structure of the blowing shell of a high-precision external cylindrical grinding machine for a lead frame proposed by the utility model.

[0022] Legend Explanation:

[0023] 1. Spindle; 2. Driven shaft; 3. Chuck; 4. Ejector pin; 5. First suction shell; 6. Second suction shell; 7. Second blowing shell; 8. First blowing shell; 9. Air pipe joint; 10. Fixed frame; 11. Suction groove; 12. Suction cavity; 13. Suction hole; 14. Through hole; 15. Inner jacket; 16. Blowing cavity; 17. Communication groove; 18. Blowing groove. Detailed Embodiment

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0025] Refer to Figures 1 to 3, A high-precision external cylindrical grinder for a lead frame provided by the utility model: includes a bed body and a power device, a grinding wheel assembly, a diamond wheel dresser, a cooling assembly, an air pump, a negative pressure pump, a dust removal box, a main shaft 1 and a driven shaft 2 arranged inside the bed body. The main shaft 1 and the driven shaft 2 are arranged opposite to each other left and right, and chucks 3 and thimbles 4 are respectively arranged at opposite ends. In this embodiment, the structure and working principle of the external cylindrical grinder are basically the same as those of the prior art, and it is improved for the problem that abrasive grains will fall on the surface of the part during wheel dressing, causing subsequent grinding damage;

[0026] As Figure 1 , Figure 3 shown, in order to protect the surface of the part, a blowing shell for forming an annular protective air curtain on the surface of the part during wheel dressing is sleeved on the outer wall of the thimble 4. The blowing shell is composed of a first blowing shell 8, a second blowing shell 7 and an inner jacket 15. The first blowing shell 8 is sleeved on the outer wall of the thimble 4. The second blowing shell 7 and the inner jacket 15 are both threadedly connected to one end of the first blowing shell 8 away from the driven shaft 2, and the second blowing shell 7 is located outside the inner jacket 15. An annular blowing cavity 16 is arranged inside the first blowing shell 8 and around the through hole 14. A blowing groove 18 is formed between the inner side wall of the second blowing shell 7 and the outer wall of the inner jacket 15. The end of the blowing groove 18 away from the first blowing shell 8 is provided with a constriction that contracts inward. One end of the first blowing shell 8 facing the blowing groove 18 is provided with a communication groove 17 for communicating the blowing cavity 16 and the blowing groove 18. The compressed air generated by the air pump enters the blowing cavity 16 along the pipeline and the air pipe joint 9, then enters the blowing groove 18 along the communication groove 17, and is blown out from the end of the blowing groove 18 facing the chuck 3. Since the left end of the blowing groove 18 is provided with a constriction that contracts inward, the flow rate of the compressed air when it is blown out is greatly increased, and an annular air curtain is formed on the surface of the part between the thimble 4 and the chuck 3, so that the abrasive grains generated during wheel dressing will not fall on the surface of the part;

[0027] As Figure 1 , Figure 2 shown, in order to suck away the airflow generated by the blowing shell, a suction shell for sucking away the airflow blown out by the blowing shell is sleeved on the outer wall of the chuck 3. The suction shell is composed of a first suction shell 5 and a second suction shell 6 distributed left and right. An annular suction cavity 12 is arranged inside the inner wall of the first suction shell 5 and around the through hole 14. A suction groove 11 is arranged at one end of the second suction shell 6 away from the first suction shell 5. A plurality of suction holes 13 for communicating the suction groove 11 and the suction cavity 12 are arranged on the inner wall of the second suction shell 6. The plurality of suction holes 13 are all circumferentially equally distributed around the axis of the suction shell. The negative pressure pump creates a negative pressure inside the dust removal box. The dust removal box adsorbs the inside of the suction cavity 12 through negative pressure via the pipeline and the air pipe joint 9, and then sucks away the airflow generated by the blowing shell through the suction holes 13 and the suction groove 11, avoiding the airflow mixed with abrasive grains from blowing towards the chuck 3 and then transferring to the surface of the part, resulting in the failure of protection;

[0028] AsFigure 1 , Figure 2 and Figure 3 As shown in Figure 3 , in order to avoid heat generation and wear caused by high-speed rotation during grinding, through holes 14 that penetrate from left to right are provided inside both the air blowing housing and the air suction housing. The air blowing housing and the air suction housing are respectively sleeved on the outer walls of the ejector pin 4 and the chuck 3 through the through holes 14. Gaps are provided between the inner side walls of the through holes 14 inside the air blowing housing and the outer wall of the ejector pin 4, and between the inner side walls of the through holes 14 inside the air suction housing and the outer wall of the chuck 3. There is no contact between the air blowing housing and the ejector pin 4, and between the air suction housing and the chuck 3, thus avoiding the problems of heat generation due to friction and wear under high-speed rotation.

[0029] As Figure 1 shown, in order to fix the air suction housing and the air blowing housing, fixing brackets 10 for fixing to the lathe bed are provided on the outer walls of the second air blowing housing 7 and the second air suction housing 6. The air blowing housing and the air suction housing are respectively fixedly connected to the lathe bed through a set of fixing brackets 10. Through the fixing brackets 10, the air suction housing and the air blowing housing can be conveniently fixed to the inner rear wall, the inner front wall, and the inner lower wall of the lathe bed.

[0030] As Figure 1 , Figure 2 and Figure 3 shown, air pipe connectors 9 are fixedly connected to the upper walls of the first air blowing housing 8 and the first air suction housing 5. The air pipe connector 9 on the upper wall of the first air blowing housing 8 is connected to an air pump through a pipeline, and the air pipe connector 9 on the upper wall of the first air suction housing 5 is connected to a dust removal box through a pipeline. One end of the dust removal box away from the first air suction housing 5 is connected to a negative pressure pump. Through the two groups of air pipe connectors 9 and pipelines, the air blowing housing and the air suction housing can be conveniently connected to the air pump and the dust removal box.

[0031] Working principle: Before rolling the lead frame material, the roll of the rolling equipment is highly polished by this external cylindrical grinder. By improving the surface finish of the roll, the rolling quality of the lead frame material is improved. The air pipe joint 9 on the upper wall of the first air blowing shell 8 is connected to an air pump through a pipeline, and the air pipe joint 9 on the upper wall of the first air suction shell 5 is connected to a dust removal box through a pipeline. One end of the dust removal box far away from the first air suction shell 5 is connected to a negative pressure pump. Through the two groups of air pipe joints 9 and pipelines, the air blowing shell and the air suction shell can be conveniently connected to the air pump and the dust removal box. The compressed air generated by the air pump enters the air blowing cavity 16 along the pipeline and the air pipe joint 9, then enters the air blowing groove 18 along the communication groove 17, and is blown out from the end of the air blowing groove 18 facing the chuck 3. Since the left end edge of the air blowing groove 18 is provided with a converging opening that contracts inward, the flow rate of the compressed air when blown out is greatly increased, forming an annular air curtain on the surface of the part located between the thimble 4 and the chuck 3, so that the abrasive grains generated during dressing the grinding wheel will not fall on the surface of the part. The negative pressure pump creates a negative pressure for dust suction inside the dust removal box. The dust removal box adsorbs the inside of the air suction cavity 12 through negative pressure via the pipeline and the air pipe joint 9, and then sucks away the air flow generated by the air blowing shell through the air suction holes 13 and the air suction grooves 11, avoiding the failure of the protection caused by the air flow mixed with abrasive grains being blown towards the chuck 3 and then transferred to the surface of the part again.

[0032] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-precision external cylindrical grinder for lead frames, characterized in that: It includes a bed body, and a power device, a grinding wheel assembly, a diamond wheel dresser, a cooling assembly, an air pump, a negative pressure pump, a dust removal box, a main shaft (1) and a driven shaft (2) arranged inside the bed body. The main shaft (1) and the driven shaft (2) are arranged opposite to each other left and right, and chucks (3) and thimbles (4) are respectively arranged at the opposite ends. A blowing shell for forming an annular protective gas curtain on the surface of the part during wheel dressing is sleeved on the outer wall of the thimble (4), and a suction shell for sucking away the air flow blown out by the blowing shell is sleeved on the outer wall of the chuck (3). The blowing shell is composed of a first blowing shell (8), a second blowing shell (7) and an inner jacket (15). The first blowing shell (8) is sleeved on the outer wall of the thimble (4). The second blowing shell (7) and the inner jacket (15) are both threadedly connected to one end of the first blowing shell (8) away from the driven shaft (2), and the second blowing shell (7) is located outside the inner jacket (15). The suction shell is composed of a first suction shell (5) and a second suction shell (6) distributed left and right. Through holes (14) running through left and right are arranged inside the blowing shell and the suction shell.

2. The high-precision external cylindrical grinder for lead frames according to claim 1, characterized in that: The blowing shell and the suction shell are respectively sleeved on the outer walls of the thimble (4) and the chuck (3) through the through holes (14). Gaps are arranged between the inner side wall of the through hole (14) inside the blowing shell and the outer wall of the thimble (4), and between the inner side wall of the through hole (14) inside the suction shell and the outer wall of the chuck (3).

3. A high-precision external cylindrical grinder for lead frames according to claim 1, characterized in that: Fixing brackets (10) for fixing to the bed body are arranged on the outer walls of the second blowing shell (7) and the second suction shell (6). The blowing shell and the suction shell are respectively fixedly connected to the bed body through a set of fixing brackets (10).

4. A high-precision external cylindrical grinder for a lead frame according to claim 1, characterized in that: Air pipe connectors (9) are fixedly connected to the upper walls of the first blowing shell (8) and the first suction shell (5). The air pipe connector (9) on the upper wall of the first blowing shell (8) is connected to the air pump through a pipeline. The air pipe connector (9) on the upper wall of the first suction shell (5) is connected to the dust removal box through a pipeline. One end of the dust removal box away from the first suction shell (5) is connected to the negative pressure pump.

5. A high-precision external cylindrical grinder for a lead frame according to claim 1, characterized in that: An annular suction cavity (12) is arranged on the inner wall of the first suction shell (5) and around the through hole (14). A suction groove (11) is arranged at one end of the second suction shell (6) away from the first suction shell (5). A plurality of suction holes (13) for connecting the suction groove (11) and the suction cavity (12) are arranged on the inner wall of the second suction shell (6). The plurality of suction holes (13) are evenly distributed in a circumferential equal division centered on the axis of the suction shell.

6. The high-precision external cylindrical grinder for lead frames according to claim 1, characterized in that: An annular blowing cavity (16) is arranged inside the first blowing shell (8) and around the through hole (14). A blowing groove (18) is formed between the inner side wall of the second blowing shell (7) and the outer wall of the inner jacket (15). The mouth of the blowing groove (18) away from the first blowing shell (8) is provided with a constriction that contracts inward. A communication groove (17) for connecting the blowing cavity (16) and the blowing groove (18) is arranged at one end of the first blowing shell (8) facing the blowing groove (18).

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