Casting blank cost control has a small path

In automotive and construction machinery products, the proportion of the weight and quantity of castings in the whole machine is still relatively high. Under normal circumstances, since the castings are settled according to the weight unit rather than the quantity unit, when the blank castings are “fat big ears” or the price rises, the company not only makes the company pay a higher procurement cost, but also because of the processing surplus. If the amount is too large, the processing cost will be artificially increased, which will have a greater impact on the precision of the processing equipment, which is not conducive to reducing operating costs and improving economic efficiency. Therefore, in order to reduce the cost of castings, measures should be taken on the fixed accounting, structural design, quota management and procurement of casting blanks, and scientific management systems and methods should be taken seriously and properly handled.

1. Blank quota calculation and summary

To do a good job in the calculation and summary of casting blanks, we should pay attention to the following two aspects.

(1) Choosing the appropriate blank design standard castings are different according to their materials and casting methods, such as gray cast iron, ductile iron, cast steel, etc., or ordinary casting, precision casting, etc., the standards used in castings are inconsistent, the difference is The internal organization components are different, the key is that the machining allowance and surface roughness of the blank are different, and the price of the casting with high standard requirements is high. Therefore, selecting the appropriate casting standard is the basic factor affecting the price of the casting. The key to selecting the casting standard is to see the requirements for the use of the casting after processing, as well as various comprehensive use cases. The general principle is to determine the casting material reasonably, not to affect the appearance and the effect of use, to select a lower, suitable casting standard, and to select a smaller blank machining allowance, which is a good way to reduce the cost of casting blanks. In order to lay a good foundation for the economic and rationality of casting blank design.

(2) Accurate calculation of the blank weight quota The calculation method of the blank weight quota is mainly two: one is the calculation method using three-dimensional design; the other is the method of weighing. It should be noted that no matter which method is adopted, the premise is that the two-dimensional structure drawing of the casting blank must be designed according to the corresponding blank and the process requirements according to the corresponding standard, for the blank supplier and the three-dimensional design as a reference. . The main purpose of this is to avoid the loss of technical secrets of the enterprise. Since the blank drawing lacks many dimensional tolerances and geometrical tolerances of the processed parts relative to the part drawing, it can ensure that the key technical secrets of the drawing are not lost, and the two-dimensional blank is simultaneously The figure can be used as the basis for the three-dimensional design and the basis for the inspection when weighing, which can effectively avoid the occurrence of "fat head" in the cast blank.

The three-dimensional design method is to establish a three-dimensional model according to the size of the blank pattern, and then calculate the volume of the part by using the volume calculation Tool in the three-dimensional design software, and multiply the material density to obtain the weight. The weighing method is composed of the technical, inspection, disciplinary committee, finance and production departments to form the casting blank weighing acceptance group. After the blank enters the factory, the production department informs the relevant personnel of the above departments to first check the blank size. Under the premise of confirming the blank size in accordance with the blank drawing requirements, the blanks are weighed and counted, and then the personnel involved in the weighing are signed and confirmed. After the blank weight is calculated, all the blank quotas are classified, counted and summarized.

2. Processability and rationality of blank design

The craftability and rationality of casting blank design directly affects the difficulty and quality of processing, and directly affects the weight and cost of the blank. Therefore, the processability and rationality of the blank structure are also an important factor in reducing the cost of casting blanks. way. Taking the workpiece shown in Fig. a as an example, it is necessary to machine two sides of the intermediate size of 42 mm. The original structure needs to be processed to a length of 170 mm, and the structure is changed to the structure with a boss shown in Fig. b, without affecting the use effect. Not only reduces the weight of the blank, but also reduces the processing surface, which reduces the purchase cost and processing cost of the blank. This is only a small example of the design and rationality of the blank design, but it can highlight the problem. Therefore, when designing the two-dimensional blank structure, the structural processability and rationality requirements should be fully considered.

Blank structure

3. Establish a standardized blank procurement and quota management system

In order to make the casting blank, quota management and settlement system clear and transparent, it is necessary to establish a clear division of management and supervision system, and to institutionalize, standardize and standardize it so that the quota calculation and settlement of castings can be truly and effectively done. Management, prevention of loopholes, and effective reduction of casting costs.

(1) The management of rough quota calculation is limited by professional skills and other factors. The design and quota calculation of blank drawings should be handled by the technical department. There are two basic tasks: one is the blank structure drawing design; the other is the calculation of the blank quota. confirm. The technical department can confirm the weight of the blank according to the three-dimensional design method as needed, and can also confirm the weight of the blank by means of weighing with other departments. After the blank drawing design is completed, the technical department will distribute the pattern to the production department, and then the production department will issue it to the production department. Corresponding casting manufacturers are used for blank casting. After the blank quota is confirmed, counted and summarized by the technical department, it is distributed to the production and finance departments as the basis for cost accounting and checkout.

(2) Fixed cost management of blanks After the technical department has calculated and summarized the blanks, the daily rough quota management should be handled by the production department. This is because the production department is the only functional department that is connected with the casting supplier and other relevant departments of the company. The receiving and internal settlement of the castings are generally the responsibility of the production department, which can better serve as the link between the department and the department. If the casting manufacturer disagrees with the weight of the blank, the production department may submit a blank weight review, and the production department informs the relevant department to reconfirm the weight of the blank. If the calculation result is incorrect, the technical department may quota the casting blank to each department. Details are corrected. If the weight calculation is correct, the production department will feedback the feedback to the casting manufacturer and urge it to improve the casting process and size to meet the requirements of the casting blank drawing. In addition, the production department should track the market price dynamics of castings in a timely manner, and timely feedback the price fluctuations and adjustment information to the finance department.

(3) Blank quota settlement management The settlement management of the blanks shall be handled by the finance department, which is first determined by the settlement duties of the finance department, and secondly, it is beneficial for the finance department to dynamically adjust the settlement price of the castings according to the market price. The process is as follows: the production department first transmits the information of the internal casting settlement bill (mainly the type, material and quantity of the casting) to the finance department, and compares the quota of the castings issued by the technical department with the current price information provided by the production department for accounting statistics and funds. Transfer.

(4) The supervision and supervision of the calculation, management and settlement of rough quotas shall be undertaken by the Commission for Discipline Inspection or the Department of Supervision. The above-mentioned departments shall regularly hold casting price hearings to coordinate and supervise the tendering of castings and the choice of suppliers. Regularly audit and supervise the quota of castings in the technical department, the actual amount of castings in the production department, and the settlement of the financial department and the transfer of funds. In addition, regular inspections and assessments of the weight and quality of castings should be included.

Since the implementation of quota calculation, management procurement, settlement, and supervision belong to different departments, it can effectively avoid loopholes in blank management, reduce casting procurement costs, and improve the economic benefits of enterprises.

4. Introduce price competition mechanism

A strict price management system should be established in the procurement of castings. Seeking the price is not only to shop around, to choose the best, but also to compare the purchase price of other raw materials users horizontally. When determining the main channel suppliers, we must repeatedly compare them. We must choose suppliers that are contract-oriented, trustworthy, and high-quality products at low prices. We must directly purchase goods from manufacturers, and grasp the price and demand of products to reduce unnecessary information. The increase in the price of the intermediary company. At present, casting blanks are in the buyer's market in the market. The situation of oversupply is very obvious. The competition mechanism should be introduced in the procurement of casting blanks. Purchasing by means of bidding should be based on the principles of openness, fairness, fairness, merit, and credibility. . The bidding procurement may send the bidding price inquiry letter and the bidding unit quotation to the bidding unit, and then determine the winning bidding unit according to the quotation; or the bidding unit may be convened together to determine the winning bidding unit by bidding; Publish tender notices on the Internet to achieve online bidding. Since the bidding procurement introduces a price competition mechanism, the casting procurement cost can be reduced more effectively.

5. Establish quality claim and evaluation system for casting blanks

The quality of casting blanks is affected by factors such as equipment, process and personnel level of castings. The quality of castings is very different. Many castings are prone to slag inclusions and pores. These defects will leak out during the later processing and use. It not only wastes the various logistics, storage and processing costs in the early stage, but also affects the production cycle of the product. Seriously, it may even cause host failure and affect the service life of the equipment. Therefore, enterprises must do a good job in the quality claim of castings. By establishing a traceability mechanism for castings, the quality of the castings can be quickly identified, the source, batch, manufacturer and other relevant information of the casting, and the relevant casting suppliers can be traced and claimed according to the contract, which will stimulate the supply of castings. Businesses improve quality and improve service, and on the other hand, they enhance the controllability of casting suppliers.

Enterprises should regularly evaluate casting suppliers, re-plan and screen suppliers of different levels in time, clean up and eliminate uncompetitive suppliers, and fundamentally change the quality and cost of casting products to ensure that the castings are Quality, quantity, time and price requirements.

6. Establish a strict scientific price analysis management system

In the current situation where steel prices are prone to fluctuations, companies must establish a strict price management system based on market information and market conditions. To understand market price information, information technology and information network resources can be used to comprehensively compare prices. After the price target is determined, the decision makers from the enterprise to the planned procurement personnel should study the market supply and demand of raw materials and grasp the international and domestic market dynamics. Seriously analyze the contradiction between supply and demand, predict market conditions, formulate procurement plans, and timely purchase within the scope of ensuring reasonable inventory. In the case of falling market prices, it is wise to compress stocks; and when market prices pick up, raising stocks becomes a top priority. Increasing the amount of purchases and increasing the inventory at a low price can reduce the cost of castings for a large number of castings.

In short, reducing the cost of castings is an important way and means to effectively reduce the cost of manufacturing products, and it is very easy to operate and implement. The benefits generated are also very direct and obvious, and should be highly valued by enterprises.