Mitsubishi Heavy Industries Technical Review Vol. 46 No. 1 (Mar. 2009)55

Floor Type Horizontal Boring Mill “MAF150R”:
Providing the Highest Machining Efficiency in Its Class

M ACHINE TOOL DIVISIONS A L E S D E PA R T M E N T
 81-77-551-3474

In recent years, customer demand has been increasing for machine tools that offer higher
cutting performance and productivity, in addition to shorter air-cutting time, in the fields ofmedium- and large-part machining too. To address such machining needs in manufacturing
facilities, Mitsubishi Heavy Industries, Ltd. (MHI) has developed the MAF150R, a floor typehorizontal boring mill that realizes both heavy-cutting performance and reduced air-cutting time.

|1. Specifications
Table 1 lists the main specifications of the MAF150R.
Table 1 Main specifications of the MAF150R
Boring spindle diameter
Spindle taper
Ram size
Spindle speed
Spindle torqueSpindle motor output
Axis travel

Rapid traverse

Cutting feed rate
Feed thrust

Right-angle head

(mm)
(mm)
(min-1)(N·m)(kW)
Column, longitudinal X(mm)
Saddle, verticalY(mm)
Ram, in/outZ(mm)Boring spindle, in/out W(mm)
ColumnX (mm/min)
SaddleY (mm/min)
RamZ (mm/min)
Boring spindle
W (mm/min)(mm/min)
Z, W(N)X, Y(N)
Spindle diameter(mm)
Spindle end taper
Spindle speed(min-1)
Allowable spindle output(kW)

Automatic toolchanger (ATC)Tool storage capacity

Machine size

Machine mass (excluding table) (kg)
Machine height Y-axis direction (mm)Required floor
Z-axis direction (mm)area
X-axis direction (mm)(No. of tools)

Ø 150
7/24 taper ISO 50
400 x 400
7 - 3,000
2,445
30/37 (Continuous/30-min rating)
5,000 to 9,000 (in steps of 1,000)
2,500
3,000
3,500
700
700
24,000 (when X = 5,000 or 6,000mm)
20,00020,00010,000
1 to 10,000
29,40019,600Ø 110
7/24 taper ISO 50
7 - 3,000
3060 (Optional: 80 or 100)
35,000 or more
6,200 to 7,200
3,500
10,500 to 15,500|2. Features
2.1Large heavy-cutting capacity

The main components of the MAF150R are built using three-dimensional finite element
method (FEM) analysis technology and rationally formed and arranged ribs, thereby ensuring that
the MAF150R is highly rigid.
Figure 1 shows the FEM analysis model of the MAF150R. The use of "cast iron" for all themain components enabled the construction of this logical structure, which has a cross-sectional
rigidity that is 1.6 times greater than that of conventional models. Moreover, ductile cast iron

Mitsubishi Heavy Industries Technical Review Vol. 46 No. 1 (Mar. 2009)56(FCD600) with an elastic modulus equivalent to iron steel is used for the 400-mm (16”) square ram
located close to the cutting point, which improves the cutting performance when the ram isextended. The X- and Y-axes, which support the mass of the machine components, use
casting-integrated wide square slideways and opposed hydrostatic bearings for high-accuracy
machining, enabling smooth axis feed over all speed ranges from the lowest to the highest while
maintaining a high supporting rigidity.
Thanks to these enhancements, the machine has an excellent rigidity that supports both heavy
cutting and high-accuracy machining, even when the main spindle is at high in the column and at
maximum ram extention. In addition to the powerful main spindle, the MAF150R has a Ø150 mm(6") boring spindle that offers a maximum revolution speed of 3,000 min-1, a maximum torque of
2,445 N·m (1,804 ft·lb), and a spindle motor output of 37 kW (50 HP) as standard, thus achieving
the highest machining performance in this class of machines.

Figure 1 Three-dimensional FEM analysis model

2.2

High productivity through reduction of air-cutting time

Improvements have been made to the rapid traverse of the machine to reduce the timerequired for positioning in axis feeds over a wide area. The MAF150R was designed to provide arapid traverse of 20 m/min (787 ipm) or more, especially for the X-, Y-, and Z-axes that are usedmost frequently, resulting in an approximate 20% reduction in the total cutting time for a given
machining program (rapid traverse of 20m/min on X axis is applicable up to 8m). Moreover, theright-angle head, which has automatic indexing capability, and the abundant machining support
software including 5-face machining and simple centering programs realize an automated setup,
which also contributes to the reduction of the setup time.

2.3

User-friendlyWith recent improvements in productivity, customer demand has been increasing for easy
maintenance and operation. To address this issue, the MAF150R adopts a centralized arrangementof all lubrication devices to facilitate refilling and draining of lubricating oil, maintenace of thesedevices, and other maintenance tasks. In addition, for periodical maintenance items, the machine isdesigned to alert the operator by displaying the necessary information on the machine operation
panel whenever maintenance is required.
For operability, the machine offers 5-face machining software (work surface coordinate
programming type), which allows the operator to program not only the four sides of the part, butalso an additional inclined surface on the assumption that it is also an X–Y plane. Patterned
subprograms are also available, such as one for a bolt-hole circle.

|3. Future prospects
The MAF150R is a cutting-edge machine that meets the diversified machining needs in theactual manufacturing facilities. MHI identified these needs through long-term market research. The
demand for the MAF150R is expected to be focused in a variety of industrial fields, ranging fromthe machining of general machining parts and construction machine parts to the machining ofwind- and solar-power generator parts. MHI will not only promote its sales in the domestic market,
but will also actively expand its sales activities in overseas markets centered in US, Europe,
BRIC’s and other emerging countries around the world.