Valenite pneumatic control automatic compensation cylinder hole fine boring tool can better meet the precision requirements of cylinder bore machining, the most important is to achieve automatic compensation of the size of the machining center, in order to achieve the purpose of automatic control of the size of the processing. In addition, it has the same high precision and high reliability as the special machine tool. Figure 2 semi-finished cylinder bore (push) Figure 3: Fine bore cylinder bores 2. Automatic compensation on the machining center Figure 4 Pneumatic chuck device 3. High processing accuracy and reliability Intertech Machinery Inc. , https://www.taiwanmouldmaker.com
figure 1
The finishing of the cylinder bore is the highest priority in the machining of the entire engine block. In order to ensure the dimensional accuracy of the cylinder bore, shape and position tolerances and to obtain a stable Cpk value, currently imported rigid planes are commonly used in the processing of cylinder blocks in the country, and online (offline) electronic inspection tools and automatic compensation tool systems are implemented to achieve Automatic size control (automatic or semi-automatic feedback). However, with the increasingly fierce competition in the auto industry, the development and update of engines are accelerating. Rigid special-purpose machine tools are far from the requirements of flexible machining. More and more cylinder bore machining is now being transferred to higher flexibility. On the machining center. Herein, this article specifically introduces a cylinder bore boring tool for a machining center.
Figure 1 shows the newly developed pneumatic control automatically compensated cylinder bore boring tool used by the United States Valenite Company. The boring tool uses the HSK100 interface, which has many processing advantages.
1. Semi-finishing boring on the machining center
In order to meet the accuracy requirements of the cylinder bore, Valenite uses semi-finishing and fine boring to separate the tool design to avoid the vibration generated by the simultaneous processing. Semi-precision and top chamfering adopt push-pull (spindle down), and fine pull up (spindle up). During machining, the tool changer first takes the tool directly from the tool magazine to perform automatic tool change, and then the spindle is positioned to the machining position. The semi-finishing tool is first executed (three tools are processed at the same time). The tool holder remains in the original position at this time. The position, that is, the radius of the boring tool tip is smaller than the radius of the semi-finishing burr blade tip, and does not participate in the cutting (see FIG. 2). When the semi-finishing is completed, the main shaft continues to work and the top surface is chamfered. After the chamfering is completed, the main shaft retreats by 1 to 2 mm. At this time, compressed air of 0.4 to 0.6 MPa (or more) is input from the machine tool spindle through the air intake port on the side of the shank flange to the inside of the boring bar, and the compressed air is input to push the lever in the boring bar; Push a set of wedge structure, clamp the fine boring knife to the size of the finishing, and then the spindle retreats into the work for fine boring; after the boring is completed, the compressed air in the boring bar is discharged, and the ram loses pressure. The internal set of spring mechanism allows the fine burr to be clamped back to its original position and completes the entire machining cycle (see Figure 3); the spindle is then repositioned and the remaining cylinder bores are machined. 
After machining all the holes of a cylinder, the measured aperture is measured by an online inspection tool. If the size is found to be small (mainly due to the wear of the blades), the size of the fine boring tool holder needs to be fine-tuned. Before machining the next cylinder, the spindle feeds the tool to the pneumatic chuck device mounted on the clamp, see Figure 4. After the fine adjustment knob of the front end of the tool is tightened by the positioning of the pneumatic chuck, the spindle of the machine tool rotates, and the main shaft rotates clockwise or counterclockwise by 10° each, and the size of the fine boring is increased or decreased by 0.0025 mm in the radial direction, thereby realizing the finishing dimension. Automatic compensation. The maximum rotation is 360°, and the total adjustment in the diameter direction is 0.18mm. 
Valenite's unprecedented design for pneumatically controlled automatic compensation of cylinder bore boring tools achieves the same machining functions and stability at the machining center as on dedicated machines. Since the boring tool utilizes the compensation of the spindle rotation of the machining center instead of the servo motor compensation system on the special machine, the fine positioning accuracy can be guaranteed to be 0.002mm, and the cylindricity tolerance of the cylinder bore is less than 0.01mm.
4. Other features
The pneumatic control automatic compensation cylinder bore boring tool in addition to the above three characteristics, it also has the following characteristics;
(1) with internal cooling;
(2) Dynamic balance design using PCBN blades for high speed machining;
(3) Compressed air of 0.4~0.6 MPa can be directly used in the workshop, no need for additional pressure boosting equipment, or high pressure coolant of 5 MPa can be used to drive the fine boring tool holder;
(4) The adjustment accuracy is high, and the minimum adjustment amount is 0.0025mm in the radial direction;
(5) Semi-finishing, fine cutting parameters can be individually adjusted;
(6) The fine boring machine adopts pull boring processing to avoid retreat marks;
(7) High processing efficiency;
(8) Low maintenance costs.