Several factors affecting the accuracy of punch press

Views: 10     Author: DURMAPRESS     Publish Time: 2021-11-02      Origin: DURMAPRESS


Several factors affecting the accuracy of punch press

Guide language: punch is a precision machine, because the precision of a punch is to pass the precision of each part of punch to present as a whole, because the error of any part can multiply the precision of punch.

The working principle of punch press: mechanical punch is driven by the motor flywheel storage force, flywheel will conduct the force to the crankshaft, by the crankshaft will be circular movement of the force into vertical movement of the force, the force to promote the slide block to do work, so as to process the workpiece punch press

Accuracy of press body. First of all, starting from the machine fuselage material, the fuselage of the press for the normal operation of the press to provide support, fixed, stable guarantee. The rigidity and stability of the fuselage have the greatest influence on the accuracy of the press. The press body is generally processed by two processes, steel plate welding and cast steel. No matter which method of processing the fuselage need to do stress treatment, to stress part is to ensure the overall strength of the welding fuselage, weld is not easy to crack, but also make the fuselage easier to machine processing. Steel plate welding fuselage for the use of the advantages of the steel plate welding, flexibility is bigger, the processing difficulty than casting a simpler, more easily meet the non-standard customized requirements of users, with open structure punch in the guideway generally add C type cast steel welding to ensure that its strength, as part of the big tonnage punch to casting, steel plate welding fuselage for large tonnage punch more so, Including a part of low speed precision punch also in use. The cast steel fuselage is cast by mold and formed in one body. Because of the casting processing method, its internal structure is more special, which makes the fuselage absorption resonance effect stronger than the steel plate welding fuselage. At the same time, because it is formed in one body, the stability is stronger than the steel plate welding body. Due to the difficulty of processing and reprocessing, the cast fuselage can only be used in small tonnage punch and high-speed precision punch, such as ZYJ punch and JB23 punch of Central Asia Machine Tool, as well as J21 and J21S are built with cast steel fuselage. In terms of accuracy alone, the two fuselages can ensure the accuracy requirements of the machine. Only because of their respective special performance, there are differences in the scope of application.


Fuselage material is the first factor to ensure accuracy, followed by excellent processing technology is also the key factor to make material quality change.

Crankshaft gear drive shaft. Mechanical punch generally adopts gear and drive shaft for transmission, so the machining accuracy of gear and shaft concentricity, the machining accuracy of shaft hole, the accuracy of bearing and wear-resisting degree are also important factors affecting the accuracy of punch. Crankshaft for the press force conversion mechanism, is also the main force mechanism. Crankshaft is carbon steel after forging, turning, using the crankshaft precision grinding machine for grinding, and then do hard chromium plating, nitriding treatment. The strength, rigidity and wear resistance of crankshaft are guaranteed.

Slider and guide rail accuracy. Slide is the direct component for the making of work of punch, generally cast steel whole casting, or use forged steel milling processing manufacturing. Slider and guide rail accuracy is a whole, open press is generally two guide rail, guide rail using V and rectangular, V guide rail is also known as four guide rail, guide rail has four contact surface. Rectangular guide rail is also called six-sided guide rail, guide rail has six contact surfaces. All the guide plane is used for precision grinding, in the assembly process using lever instrument for measurement, and do scraping processing to ensure its precision. Closed press is generally four guide rails, generally using right-angle guide rails. The main reasons affecting the accuracy of slide block and guide rail are machining accuracy and assembly process.

Slide balance device. The slide block falls when the punch is processed. After the work is done, it will be subjected to the reaction force of the mold. The reaction force and the accuracy error of the guide rail will make the track of the slide block produce slight changes. After installing the slider balance device, the slider and the guide rail can be kept parallel.

punch 2

Slider bottom and table accuracy. Install the upper die on the bottom surface of the slide block, and install the lower die and other feeding and discharging equipment on the workbench. Both work tables are made of cast steel or forged steel plate. After casting, milling machine is first used for milling processing, and then plane grinding machine is used for grinding to ensure its accuracy. The assembly needs to use the instrument to measure, found the error in time to scratch to adjust.

Press installation environment and shock absorption footing. Large tonnage punch, precision punch, high-speed punch in the installation of the need to cast shockproof pit to install, different punch according to the location of its installation hole pin pouring. Small presses are generally installed with shockproof footing.

Assembly process of punch press. The assembly process directly determines the precision of the punch. Fifty percent of the success or failure of a press is due to the assembly process. Assembly needs to be all precision parts combined into one, each parts are unable to guarantee the absolute precision of 100%, if the permissible error of sliding block is 2, the permissible error of crankshaft is 3, so they are combined into a error instead of 2 + 3 * 3 2 so the last error is 6, assembly if the errors of two integral error will reach 12, So assembly produced a small error will double the overall error, will double reduce the precision of the press.

Maintain the press properly.


1. During the use of the punch press, lubrication should be carried out strictly in accordance with the product instructions, regular check whether the lubricating oil reserve is sufficient, check whether the lubricating oil road is smooth.

2. In the process of using the punch press, it is necessary to pay attention to whether there is abnormal sound and abnormal movement of the machine tool operation, whether there is wear and tear of the slider guide rail and bearing bearing bush.

3. If the accuracy becomes smaller, the machine should be stopped for maintenance immediately.

The accuracy of the punch belongs to an overall accuracy, is coordinated by all precision components to ensure that any only guarantee the accuracy of a few components of a component is not desirable.

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