Cylindrical grinding machine

A cylindrical grinding machine has a machine base, a driven workhead with a slide drive and a driven wheelhead with a slide drive. The machine base is formed as a fixed plate, which can be aligned horizontally or vertically. A tailstock has a slide drive which is controllable independently of the other slide drives.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a cylindrical grinding machine, having a machine 
base, a driven workhead to turn a workpiece about a rotation axis, a 
driven wheelhead to grind the workpiece and a slide drive for relative 
movement of the workpiece and the wheelhead, wherein the machine base is 
formed as a fixed plate, on which the workhead, the wheelhead and the 
slide drive are fixedly attached. 
2. Description of Related Art 
Cylindrical grinding machine is known from the US-A-4 443 975. The 
disclosed cylindrical grinding machine has a machine base which is 
adjusted a longitudinal slide, on which is mounted an upper table for the 
angle adjustment. A driven workhead and a tailstock are mounted on the 
upper table such that they are manually adjustable. The longitudinal slide 
is mounted on guides and is adjustable. The slide is equipped with a 
longitudinal slide drive. The guides are aligned parallel to the axis of 
rotation of the workpiece. Perpendicular to the axis of rotation there are 
more guides provided on which a cross slide is movable mounted and 
equipped with a cross slide drive. A driven wheelhead with a grinding 
wheel is fixed on the cross slide. The machine base is formed in one block 
and takes up a lot of space. The construction of the machine is 
complicated. 
SUMMARY OF THE INVENTION 
It is the object of the enclosed new invention to provide a simple and 
inexpensive and compact cylindrical grinding machine. 
It is a further object of the invention to provide a cylindrical grinding 
machine which can be loaded from below. 
These objects and more according to the invention are provided by a 
cylindrical grinding machine, having a machine base, a driven workhead to 
turn a workpiece about a rotation axis, a driven wheelhead to grind the 
workpiece and a slide drive for relative movement of the workpiece and the 
wheelhead, wherein the machine base is formed as a fixed plate, on which 
the workhead, the wheelhead and the slide drive are fixedly attached. 
Surprisingly it was found when using a plate with a sufficient weight for 
a machine base instead of the traditional block that the necessary 
stability is still ensured. This way a great deal of space was saved. 
In one embodiment of the invention the plate is adjusted horizontally on a 
frame. This way additional units as for example cooling filtration unit 
can be placed space-savingly under the machine base. 
In another embodiment of the invention the plate is adjusted vertically. 
This way even more space can be saved, and additionally a simple loading 
of the machine from below is possible. Also the cooling of the machine 
without damage to the machine base is possible. The cylindrical grinding 
machine according to the invention is therefore very measure-precise, 
operating- and maintenance-friendly. 
In a preferred embodiment of the invention the longitudinal slide drive 
includes a first electronic control longitudinal slide drive for the 
workhead and a second electronic control longitudinal slide drive for the 
tailstock, whereas the first longitudinal slide drive and the second 
longitudinal slide drive are independently controllable. It is a special 
advantage of this embodiment that not only all necessary functions are 
simply done by the independent longitudinal slide drives, like the 
alteration of the center distance, the clamping of a workpiece, the plunge 
grinding, the traverse grinding, the grinding of tapers and radius and so 
on, but also a simple construction is possible: table and upper table as 
well as the complicated arrangement of the combined slides are 
unnecessary. In addition the cylindrical grinding machine according to 
invention is maintenance-friendly, as the longitudinal slide drives can be 
finished identically for the most part. Also it is especially stabile, 
because it does not show any complicated adjustment of combined slides. 
This is especially advantageous when using CBN-grinding wheels and when 
working on ceramic material. 
In another embodiment of the invention, there is provided under the 
workhead and the tailstock a loading conveyer running in direction of the 
turning axis. This ensures in a space-saving way an efficient loading and 
unloading of the workpiece to be worked on. 
In another embodiment of the invention, the wheelhead includes a gripper to 
lift the workpiece from the loading conveyer and to position the workpiece 
between the workhead and the tailstock. In this arrangement, larger 
workpieces can be worked on. 
In another embodiment of the invention, a lifter is provided for the 
lifting from the loading conveyer and to hold a workpiece from below and 
to position the workpiece between the workhead and the tailstock. This has 
the advantage when clamping the workpiece in the lifter that one makes use 
of the lifter's weight. 
Some embodiments are further provided for in the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The embodiment of FIG. 1, shows a front view of a cylindrical grinding 
machine. The machine includes a fixed plate 1 as machine base which is 
mounted on a frame 2. A workhead 3 in order to hold a workpiece and to 
turn the workpiece round an axis of rotation 7 is equipped with a driven 
center 4 and adjusted on a plate 1. A wheelhead 5 to grind the workpiece 
is also mounted on the plate 1 and equipped with a driven grinding wheel 6 
which is surrounded by a protection for the grinding wheel 12. The 
workhead 3 includes a longitudinal slide drive in order to move the 
workhead in direction of the axis of rotation 7 over a guide 8. The 
wheelhead 5 includes a cross slide drive to move the wheelhead 
perpendicular to the axis of rotation 7. Furthermore, a tailstock 9 with a 
center 10 is provided to clamp the workpiece. The axis of rotation 7 is 
the symmetrical axis of the center 10. The center 10 of the tailstock 9 is 
not driven. The tailstock 9 is equipped with a longitudinal slide drive in 
order to move the tailstock in direction of the axis of rotation 7 along a 
guide 11. On the plate 1 is provided another frame 13, on which is mounted 
a cabinet 14 with control units for controlling the workhead 3, the 
wheelhead 5, the tailstock 9 and of each its slide drives. The frame 13 
can be hollow to provide space for the connection wires between the 
cabinet 14 and the devices to be controlled. Under the plate 1, a paper 
band filtration unit 15 and a hydraulic unit 16 are placed. 
FIG. 2 shows a side view of the cylindrical grinding machine shown in FIG. 
1. The same reference symbols are used for identical units. The wheelhead 
5 can be moved along a guide 17. 
The machine base is made of heavy, solid material, for example of granite 
or of another suitable type of stone, or also of steel, iron, or of 
another suitable metal. Conventional cylindrical grinding machines have a 
machine base which is formed of one block. When using a plate with a 
sufficient weight for a machine base instead of the traditional block, the 
necessary stability is ensured. This way a great deal of space can be 
saved. Additional units, for example cooling filtration unit 15 and 
hydraulic unit 16 can be placed space-savingly under the machine base. 
The longitudinal slide drives are independently electronically controllable 
in order to move the workhead 3 and the tailstock 9 in direction of the 
rotational axis 7. This way, all necessary functions, such as the 
adjustment of the center distance, the clamping of the workpiece, the 
plunge grinding, the traverse grinding, the grinding of tapers and radius 
and others can easily be accomplished. Conventional cylindrical grinding 
machines are equipped with a driven longitudinal slide and with an upper 
table for the angular adjustment, which can be moved in direction of the 
rotational axis and on which the workhead is fixed as well as the 
tailstock. All functions of these conventional cylindrical grinding 
machines with longitudinal slide and upper table are possible for the 
machine according to invention because of the identical control of the two 
longitudinal slide drives. The workhead 3 and the tailstock 9 and 
therefore also the held workpiece follow the same movement. Further 
functions, like the adjusting of the center distance or the clamping of a 
workpiece, are simplified by the separate control of the two longitudinal 
slide drives. Also, the structure is less expensive and simpler in 
comparison to known cylindrical grinding machines: longitudinal slide and 
upper table as well as the complicated arrangement of the combined slides 
are unnecessary. Also, the cylindrical grinding machine according to 
invention is very maintenance-friendly, because the longitudinal slide 
drives can be finished identically of each other. Furthermore the machine 
is especially stabile, because it does not have complicated arrangement of 
combined slides. This is in particular advantageous when using CBN-wheels 
and when working on ceramic material. The grinding of tapers and cylinders 
(radius) takes place by interpolation. Here, the control of the feed 
motions of the wheelhead 5 on the one hand and the workpiece clamped 
between the workhead 3 and the tailstock 9 on the other hand are 
controlled such that the required shape is being grounded. Therefore the 
angular adjustment is unnecessary and the cylindrical grinding machine 
does not need an upper table. It is pointed out, even if the independently 
controllable longitudinal slide drives in connection with the plate-formed 
machine base are especially advantageous, that they can also be used 
independently of this. 
FIGS. 1 and 2 show a cylindrical grinding machine according to the 
invention. Here, the wheelhead 5 is equipped with means to grind threads 
in the workpiece, which result in a thread grinding machine according to 
the invention. 
A cylindrical grinding machine shown in FIGS. 1 and 2 shows an interior 
grinding machine according to the invention. The workhead 3 is suitable to 
hold the workpiece. The wheelhead 5 is put in place of the tailstock 9 and 
has one or several grinding spindles of which the rotational axis for 
example runs parallel to the rotational axis 7 of the workhead 3. By means 
of the wheelhead 5 the machine grinds the inside of the workpiece held by 
the workhead 3. 
FIG. 3 shows a front view of a centerless grinding machine according to the 
invention. A workrest plate 31 is provided to hold a workpiece 32. The 
workhead 3 is a head of regulating wheel and has a regulating wheel 33, 
which is put in a splash guard 34. The head of regulating wheel 3 is 
suitable to turn the workpiece 32, whereas the wheelhead 5 by means of the 
grinding wheel 6, which one turns much quicker than the head of regulating 
wheel, processes the workpiece 32. The cabinet 14 with devices to control 
the workhead 3, the wheelhead 5 and each of its particular slide drive is 
connected with the devices to be controlled by connection wires 35. The 
control can for example be made from a screen 36, which is also, in a not 
shown manner, fixed to the plate 1. 
FIGS. 4 and 5 show a front view and a side view respectively of another 
cylindrical grinding machine according to the invention. The machine base 
is built as a vertical plate 1, so that even more space can be saved. The 
plate is mounted on a fixture 41. The workhead 3, the wheelhead 5, and the 
tailstock 9 are adjusted movably with its particular slide drive on the 
particular guide 8, 17, 11 on the plate 1. The particular slide drives are 
again independently electronically controllable. Also in this very solid 
and space-saving implementation form are therefore all the necessary 
functions ensured. The cabinet 14 with the control devices is mounted 
behind the plate. The connection wires, not shown, can be taken through 
the plate 1 and/or around the plate 1. When cooling the cylindrical 
grinding machine, the coolant drops vertically and does therefore not 
touch the machine base. Thus, there is no additional heating of the 
machine base, and the measure-precision of the cylindrical grinding 
machine is higher. As clarified below a simple loading of the machine from 
below is as well possible. Therefore, the cylindrical grinding machine 
according to invention is also very operating-friendly. Under the workhead 
3 and the tailstock 9 is located a loading conveyer running along in 
direction of the rotational axis 7 to ensure an efficient loading and 
unloading of the workpiece to be processed. The wheelhead 5 can have a 
gripper to lift the workpiece from the loading conveyer 42 and to position 
the workpiece between the workhead 3 and the tailstock 9, so that larger 
workpieces can be processed. In another implementation form a lifter 43 is 
provided for the lifting from the loading conveyer 42 and to hold a 
workpiece from below and to position the workpiece between the workhead 3 
and the tailstock 9. This way the weight of the lifter 43 is being used 
when holding the workpiece. 
The vertical adjustment according to the invention is applicable for the 
center grinding machine as well as for the centerless grinding machine, 
the internal grinding machine and the thread grinding machine.