Boring machine fixture also known as boring die, mainly used for processing box or bearing parts on the precision hole and hole system. It mainly consists of boring base, bracket, boring sleeve, boring bar and necessary positioning and clamping device. The type of jig of boring machine is divided into double support boring mold, single support boring mold and no support boring mold according to the arrangement of guide bracket.
A typical structure of jig of boring machine
(1) front and rear double support boring die
(2) no support boring machine fixture
Two, boring machine fixture design points
1. Guide mode and guide bracket
Boring bar guide is divided into single, double support guide.
Single support, boring bar and machine tool spindle rigid connection, spindle rotation accuracy affects the accuracy of boring, so suitable for small hole and short hole processing.
When double support, boring bar and spindle of machine tool adopt floating connection. The position accuracy of the boring hole depends on the position accuracy of the two guide holes of the boring die, and has nothing to do with the precision of the machine tool spindle.
The boring guide bracket is mainly used to install the boring sleeve and bear the cutting force. Because it is required to have enough rigidity and stability, so in the structure should generally have a larger installation base surface and the necessary reinforcement; Moreover, the clamping mechanism is not allowed to be installed on the bracket to bear the clamping reaction force, so as not to destroy the accuracy of the bracket deformation.
2. Boring set
The structure and precision of boring sleeve directly affect the precision of the machined hole. Commonly used boring sleeve is:
(1) fixed boring set fixed boring set small size, simple structure, high precision guide, but the boring bar in the boring set side rotation, side axial movement, easy to wear, so only suitable for low speed boring.
(2) rotary boring sleeve rotates with the boring bar, and there is only relative movement between the boring sleeve and no relative rotation. This boring sleeve greatly reduces wear and tear, and will not be “stuck” due to friction and fever. Therefore, it is suitable for high-speed boring.
3. Boring bar and floating joint
Boring bar is an important part of boring die. The diameter d and length of the boring bar are mainly determined according to the diameter D of the boring hole and the tool section size B×B (refer to the value in Table 11.1). The diameter d of boring bar should be as large as possible, and the L/ D of the double guiding part should be less than or equal to 10. The L/ D of the overhanging part is less than or equal to 4 ~ 5, so that it has enough stiffness to ensure the machining accuracy.
For fixed boring sleeve boring rod introduction structure has two types of integral and insert.
When double support boring and boring, the boring bar is connected with the main shaft of the machine by floating joint.
