Fixture Design and Economic Analysis

0 Introduction The structural commonalities of modern fixtures (such as group fixtures, universal fixtures, and combination fixtures) are mostly composed of a general-purpose matrix, adjustable and replaceable components. The universal base part is the main part shared by all parts in the parts group; and the adjustable and exchangeable parts are special or quasi-specific parts designed specifically for one (or several) specific parts in the parts group. Adjustable and exchangeable components generally vary with the number of fixtures to be used. Therefore, in the design of modern fixtures, whether the number of applicable objects is properly selected will directly relate to the number of adjustable and exchangeable components and fixtures. The overall economics are discussed and studied with the group fixture as an example. 1 Optimization design analyzes the characteristics of this optimized design: The number of applicable objects can be correctly determined. According to the result of the optimization design, the structural design of the adjustable, exchangeable component and the universal base body is adjusted from the perspective of the cost ratio, so that it can satisfy the optimization design and achieve the overall economical purpose. Cost of group fixtures Cost of group fixtures Cc = Ct + PN (1) Where: Ct - cost of universal bases on group fixtures, P; unit - adjustable, average parts of exchangeable units on group fixtures Pieces of cost, yuan / species; N - group fixture suitable for the number of species, species. In equation (1), t is a constant for the entire fixture; PN changes as N increases or decreases (where P is a constant). The two basic concepts for measuring the economics of group fixtures can be considered from the cost of fixtures shared by the number of applicable fixtures in the group fixture. The applicable objects can be allocated to the fixtures within the full load range of the fixture. The lower the unit cost for the number of applicable objects is. From the perspective of the adjustable and exchangeable components on the fixture, as the number of applicable objects of the fixture increases, the adjustable and replaceable components on the fixture also increase. In this case, the design and manufacture of the adjustable and replaceable components are increased. The cost and number of fixture adjustments, adjustments, and storage costs also increase accordingly. The two contradictory factors mentioned above have different effects on the economy of the jigs. The following two basic concepts will be further elaborated through the establishment of mathematical models. Establishing a mathematical model From equation (1), it is known that when 1 â‰¤ N â‰¤ Nx, where Nx is the number of applicable objects when the fixture is at full load, the unit cost of the group fixture is assigned to the number of applicable objects P0 = Ct +PN N (2) (2) Costs for adjustable and replaceable components in the complete set of fixtures PTW=PN (3) Establishing a mathematical model F Adding formulas (2) and (3) to obtain F=P0 +PTW=Ct+PN +PN N (4) The solution of the optimal number NK is assumed to be: Ct=1,000 yuan, P=50 yuan/ton, Nx=100 kinds To find the minimum value K for the differential equation (4). That is to say, the NK value must be such that dF/dN = 0, that is, F' = -Ct + P N2, and if F' = 0, then N = (Ct/P)1â„2. (5) N obtained in equation (5) is NK, and 1â‰¤NKâ‰¤Nx. NK=(1,000/50)1â„2â‰ˆ4.5 Integral number, then NK=5 kinds, this NK value, that is, when Ct=1,000 yuan, P=50 yuan/kind, the fixture is suitable for the optimal number of species Numerical value. 2 The practical significance of optimizing the design When the group fixture is designed and the number of applicable parts is equal to or close to the NK value, the group fixture can be considered to meet the economic principle; conversely, it can be considered as unreasonable from an economic point of view. of. At this time, adjustment measures should be taken from various aspects, such as modifying the structural design of a general-purpose matrix or adjustable and exchangeable components, so that the proportional relationship between the Ct value and the P value can be adjusted, and finally meet the economic principle. In the jig design, according to the complexity of the fixture, the equivalent values â€‹â€‹of the Ct and P values â€‹â€‹are obtained from the accumulated statistical data, and the number of target parts for the predetermined group jig is applied, and then the actual Ct value and the P The value is evaluated so that the purpose of reducing process losses can be achieved. In order to optimize the design of the jigs, the NK must be solved, but once they have mastered their internal mathematical relations, it is not necessary to solve them one by one in each jig design, in order to achieve the purpose of improving design ergonomics. You can improve the optimization design and evaluation efficiency by establishing a quick checklist. This cheat sheet can be established based on a very simple rms relationship. See Table 1 for details. Table 1 Quick Lookup Table Ct/PTW 4 9 16 25 36 49 64 81 100... NK 2 3 4 5 6 7 8 9 10... The NK values â€‹â€‹listed in Table 1 can be used to determine the NK value in the optimum design, or After design, use the NK values â€‹â€‹listed in Table 1 to test the economics of the design conclusion. If the NK value is equal to or close to the list, then the design can be determined from the economic point of view to achieve the purpose of optimizing the design. Otherwise, the design plan should be modified accordingly until it reaches or approaches the NK value. According to this method, general chemical equipment design can greatly reduce the cost of tooling and shorten the product development cycle. Because the general fixture accounts for 1/5 to 1/10 of the total tooling in product development, its manufacture can be completed by the company's mechanics, and the arrival time of fixtures is reduced from the original months to several days. Can greatly reduce the fixture inventory. Estimated by the minimum inventory of tooling inventory, inventory is 2 to 3 times the amount of the site, and the universal fixture will reduce the number of fixtures used in the original site from a few hundred to dozens, and inventory can be reduced to 1/2 ~1 times the production amount. Greatly improve the throughput of stand-alone equipment and improve product quality. Due to the difference in tooling, similar equipment at the site affects the wide process capability of the equipment itself. The general tooling improves the overall equipment passing capability of the site, which is conducive to balanced production and improves process quality and product quality. Improved on-site resilience and single-species processing capabilities are conducive to smooth logistics and balanced production.

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Export Country:US.UK.SERBIA,RUSSIA,ITALY,IRAN,KOREA,JAPAN,SPAIN,CHILE,BRAZIL

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Radius Type:1.5D(Long),1.0D(Short)

Surface Finish:Nature Surface,Sand Blasting,Painting.

Material:SS 304/304L/316/316L/201/430,CS Q235/A234/Q195/A105/20#/16MN