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Hemming technology, it is to apply a certain external force, so that the edge of the stamping part could turn inside, to cover another stamping part, so that the two stamping parts are joined together. The process is shown in picture 1.There are usually two forms after roller hemming: flat side and ring wrap, as shown in picture 2 & 3.
??Nowadays hemming technology are widely used in automobile manufacturing field, especially widely used in doors & covers assembly production. There are usually three kinds of hemming technology: Hemming Press, Table Top Hemming, Robot Hemming System. Follow with the detail introduction of three different kinds of hemming technology.
No.1 Press Hemming
1、Components of the System
Press hemming system consist of press machine, upper & lower die, transmission mechanism, electric control system, the transmission mechanism could be manual manipulator, also could be automatic manipulator, or robot handling.
the principle of hemming forming
the pressure of hemming forming
classification, measurement, manufacturer of press hemming.
Remark: Generally, the overhead crane guide rail and the ground installation guide rail are required to switch the maintenance tooling die, which is required for the ground bearing strength and the height of the plant.??
2、Manufacturing cost
Take the hood of the engine as an example, the completion of a working process, which is required 1 set of pressing machine system about 2.6 million RMB, 1 set of upper and lower tooling die about 1.3 million RMB, the total amount is 3.9 million RMB.
3、Floor area
What’s the general size of press hemming? Take the hood of the engine as an example. The outline dimension of the engine cover assembly is 1100mm x 1500mm.So what is the outline size of the system upper and lower tooling die? What’s the occupied floor area of system?
The example of this article is 150t, 4 columns / section, 2000mm×2000mm.
4、Production cycle
Remarks: The work cycle is considered without equipment mobility, starting from a system cycle to the end of the system cycle.
Working cycle the press hemming system is directly proportional to the turn up angle of part, general turn up angle is < 105 °, it require 1 working process; When turn up angle > 105 °, require 2 process (the first process is hemming, the second process is hemming). It's easier to handle around the angle.
5、Flexibility?
Production flexibility: the flexibility is very good, when changing the model, it just needs to change the hemming tooling die. Short changing time, generally only require 10 mins. It needs to be built.
Transporting flexibility: the pressure machine has a very high standard for civil engineering. Generally do not to transport, what should be paid attention to when installing? How long will it take to resume production?
??6、Product Quality??
There are two aspects to the product quality: the quality of the incoming product and the quality state after the molding.
A. the quality requirements of products
B. Quality status after molding.
Press hemming, the surrounding contour is formed at one time, the pressure is applied evenly on the parts, so the outer surface of the part is of high quality and good quality, and the product is in good stability.
However, due to its poor adaptability, it will take a long time to repair the mold to eliminate the quality defects once the quality defects of the molding products have appeared.
7、Commissioning period and Commissioning cost.????
As mentioned earlier, the press hemming comes from the upper and lower tooling die. The tooling die can be repaired and maintenance outside the press machine without affecting the production of other models of parts. Generally speaking, it will take about 1 week to debug the finished product and 30~50 pieces of the finished product should be adjusted in the case of stable stamping parts.
8、Production maintenance????
A. Equipment maintenance, motor maintenance, system electrical maintenance.
B. Maintenance, tooling die repair and maintenance.
C. Skilled in personnel requirements, familiar with tooling die system and electrical program in reading.
二、Table Top Hemming
1、Components of the System
Table top hemming system consist of pressing die, transmission mechanism, electric control system, the transmission mechanism could be manual manipulator, also could be automatic manipulator, or robot handling.
Remarks: The work cycle is considered without equipment mobility, starting from a system cycle to the end of the system cycle.
There are many kinds of hemming process, mainly are upper die, lower die movement or stationary. Examples are as follows:
Similar to the traditional press hemming, there is the upper and lower die, but the upper die is driven by the motor.
2、Manufacturing cost
Take the hood of the engine as an example, the completion of a working process, required 1 set of pressing machine system about 4 million RMB.??
3、Floor area
Take the hood of the engine as an example. The outline dimension of the engine hood assembly is 1100mm x 1500mm.So the outline dimension of the pressing die is 2600mm x 3100mm, system floor area is 3345mm x 11425mm.
4、Production cycle
Remarks: The work cycle is considered without equipment mobility, starting from a system cycle to the end of the system cycle.
Working cycle of the table top hemming system is directly proportional to the turn up angle of part, general turn up angle is < 105 °, it require 1 working process; When turn up angle > 105 °, require 2 process (the first process is hemming, the second process is hemming). It's easier to handle around the angle.?
5、Flexibility
Production flexibility: No flexibility, although upper die could be disassembly, it needs to plenty of time to reinstall to reach quality products. Require long time to resume production. It is not fit for producing after-sale spare parts.
Transporting flexibility: Do not require civil engineering, not fit for transporting. It does not only require to adjust the pressing platform and also require to install the transfer mechanism accurately. The relocation is actually equivalent to the installation and debugging of new equipment. It will take a long time to resume production.
6、Product Quality
There are two aspects to the product quality: the quality of the incoming product and the quality state after the molding.
A.The quality requirements of products
Table top hemming technology, is a very sensitive systems, it can't overcome some minor defects of the parts, such as the change of turning up length and angle. Poor adaptability.
B. Quality status after molding.
Table top hemming, the peripheral contour is formed at one time, the pressure is applied evenly on the part, so the surface quality is high. The product quality stability is better. However, due to its poor adaptability, it will take a long time to repair the mold to eliminate the quality defects once the quality defects of the molding products have appeared.????
7、Accessory equipment
The parts cannot be moved in manually, and it must use dedicated transmission mechanism to carry out the parts, such as manipulator, robot, reciprocating mechanism, etc.
8、Commissioning period and debugging cost.
As mentioned earlier, the press hemming comes from the upper tooling die, requiring & maintenance tooling die could be taken on after completion of system installation. Generally speaking, it will take about 1 week to debug the finished product and 30~50 pieces of the finished product should be adjusted in the case of stable stamping parts.
9、Production maintenance????
A. Equipment maintenance, motor maintenance, system electrical maintenance.
B. Maintenance, tooling die repair and maintenance.
C. Skilled in personnel requirements, familiar with tooling die system and electrical program in reading.
三、Robot Hemming System
1、Components of the System
Robot hemming system consist of robot, lower die, roller and electric control system.
2、Manufacturing cost
Take the hood of the engine as an example, 1 set of robot hemming system require about 2 million RMB.
3、Floor area
Take the hood of the engine as an example. The outline dimension of the engine cover assembly is 1100mm x 1500mm.So the outline dimension of the pressing die is about R=1000mm, system floor area is 3000mm x 4500mm.
4、Production cycle
Assembly Category Perimeter(mm) Turn Up Angle Work Cycle(s) Hemming Procedure
Remarks: The work cycle is considered without equipment mobility, starting from a system cycle to the end of the system cycle.
Working cycle of the robot hemming system is directly proportional to the turn up angle of part & complexity of turn up curve surface , while general turn up angle is < 105 °, it require 3 times roller hemming; When turn up angle > 105 °, it require >3 times roller hemming.
5、Flexibility
Production flexibility: The Robot hemming system, hemming is done by robots, and the trajectory of robot can be done through programming, changing the pressing mold, reprogramming to achieve flexible production. The flexibility of here is, of course, in view of switching the model, in the automobile production cycle, it can't switch pressing mould repeatedly, because it take quite a long time to switch mould, and every change mould can make quality change. The flexibility here is also suitable for the production of spare parts after halt production.
Transporting flexibility: Do not require civil engineering. Fit for transporting, using forklift, Whole removal it only require to adjust the pressing platform and confirm programming, it doesn’t need to change program, only small modification as maximum, resume production in a short time.
6、Product Quality
There are two aspects to the product quality: the quality of the incoming product and the quality state after the molding.
A.The quality requirements of products
Robot carrying roller to hemming, it can overcome a small defect in the quality of the parts, such as oil pollution, burr, turn up length < 2 mm, turning up angle greaten < 10 °.Strong adaptability of incoming defects.
B. Quality status after molding.
Robot roller hemming, the peripheral contour is not formed at one time, it is done step by step.
7、Commissioning period and debugging cost.
As we mentioned earlier, hemming forming is by the trajectory of robot programming. In this way, it can proceed offline simulation program in advance, after completing installation, write it to the robot controller directly, you just need to do small track modification of the program. Generally speaking, it will take about 3 days to debug the finished product and 10~20 pieces of the finished product should be adjusted in the case of stable stamping parts.?
8、Production maintenance????
A. Equipment maintenance, motor maintenance, system electrical maintenance.
B. Maintenance, tooling die repair and maintenance.
C. Skilled in personnel requirements, familiar with tooling die system and electrical program in reading.