JP4719596B2 - Machine tool headstock - Google Patents

Description

  The present invention relates to a headstock device for a NC lathe or a lathe machine tool in which a spindle constituting a spindle rotatably attached to a headstock is driven by a motor separately from the headstock, for example.

  Normally, a spindle in a machine tool is configured by using a unit (quill spindle head) supplied from a bearing manufacturer. Most of these quill headstocks are equipped with a flange on the spindle case that supports the quill so that the quill that constitutes the main shaft is attached to the machine body on the load side where the chuck is mounted. It has a structure that is bolted to a base or headstock. In other words, the quill headstock is configured in a cantilever structure in which a spindle case that rotatably supports the quill is fixed to the spindle stock by a flange portion. An advantage of such a quill headstock is that the displacement (thermal expansion difference) due to heat with respect to the headstock can be released to the anti-load side (usually the side where the drive belt is attached).

  An NC lathe capable of finishing the disk surface of the aluminum wheel into a mirror surface by cutting is known. The NC lathe includes a bed, a headstock having a main shaft, a drive motor that rotates the main shaft, a chuck mounted on the front end of the main shaft, a reciprocating table that reciprocates with respect to the main shaft, and a tool post that reciprocates on the reciprocating table. The main shaft is rotationally driven via a belt by a rotational force from a drive motor (see, for example, Patent Document 1).

In addition, many built-in motor type spindle devices for machine tools are known. The spindle device of the machine tool has a hollow spindle with a tool attached to the tip, and is coaxially arranged in the spindle so as to be able to move in an axial direction that does not rotate with respect to the spindle, and moves axially to the tip of the spindle. A draw bar for attaching and detaching the tool, and a disc spring for urging the draw bar in a direction to grip the tool with respect to the main shaft. Both ends of the main shaft are rotatably attached to the fixed housing via bearings. A motor that rotationally drives the main shaft is disposed between the main shaft and the fixed housing. The motor is composed of a rotor attached to a main shaft and a stator attached to a fixed housing (for example, see Patent Document 2).
JP 11-197903 A JP 2001-269803 A

  By the way, in the spindle device of the built-in motor type machine tool as described above, the motor is positioned between the bearings that rotatably support both ends of the spindle on the fixed housing. , The main shaft does not resonate or bend due to the rotational driving force, and the workpiece does not suffer from problems such as chatter during cutting.

  However, although the above quill type headstock has the advantage that the displacement due to heat to the headstock can be released to the non-load side, the mounting structure of the spindle case to the headstock is a cantilever structure. For lathes, for lathes, it has a detrimental effect on parting, the width of the parting tool, the feed amount, the length from the end face to the machining location, etc. In the machining of a tooth lathe, chattering occurs in the parting tool machining.

  An object of the present invention is to solve the above-mentioned problem, and to prevent chattering and the like that have occurred during cutting in a conventional quill headstock in which the quill is supported by a cantilever structure on the spindle stock. In order to eliminate the disadvantages of numerical values such as number and damping properties, the quill is constructed as if it were supported by a double-supported structure, and the parting process in the lathe, the width of the parting tool, the feed amount, and the end surface It is an object of the present invention to provide a head stock apparatus for a machine tool, which is improved so as to be advantageous for the length of the machine tool.

The present invention provides a hollow quill that constitutes a main shaft that is rotatably supported on a main shaft via a bearing, a chuck for attaching a work attached to one end of the quill, and provided at the other end of the quill A machine tool comprising a turret that reciprocates in the X-axis direction and the Y-axis direction for mounting a power transmission means, a motor that rotationally drives the power transmission means, and a tool for machining the workpiece;
The headstock includes a spindle case having a hollow portion for rotatably supporting the quill via the bearing, and a flange portion provided at an end portion of the spindle case by inserting the spindle case into the hollow portion. A head stock that is tightened and fixed in the axial direction by bolts, and a slit ring that is fixed to the head stock so as to be removable. The slit ring fixed to the head stock is An inner peripheral surface is in contact with an outer peripheral surface of the other end of the spindle case to support the other end of the spindle case ;
The slit ring is fastened to the outer peripheral surface of the spindle case by a third bolt having a reduced inner diameter with respect to the outer peripheral surface of the spindle case, and is tightened axially to the head stock by the second bolt. It is related with the headstock apparatus of the machine tool characterized by being fixed to the said headstock.

  The power transmission means for transmitting the rotational driving force of the motor to the quill includes a pulley attached to the end of the quill, a pulley attached to the output shaft of the motor, and a belt hung on both pulleys. It is configured.

  As described above, the headstock device of this machine tool is configured as a both-end support structure in which both ends of the quill are attached to the headstock by bolts and slit rings. , Without being bent or generating vibration, the headstock is stably and firmly supported, and when the workpiece mounted on the quill is cut with a cutting tool, chattering or the like occurs in the machining accuracy, Therefore, the workpiece can be cut with high accuracy without adversely affecting the numerical value of the damping number, for example, the width of the parting tool can be increased on a lathe, and the feed of the tool during machining can be increased. The amount could be set large. In addition, the conventional quill type headstock has chatter and the like, and can only be cut off at the position of the end surface of the chuck claw. However, the headstock device of the machine tool of the present invention has, for example, an outer diameter of SCM45 material of φ60. Even when the cut-off tool with a width of 4.5 mm was separated from the end face of the nail by 45 mm, chattering did not occur and cutting could be performed satisfactorily.

  Hereinafter, an embodiment of a head stock apparatus for a machine tool according to the present invention will be described with reference to FIGS. The machine tool provided with the headstock device according to the present invention is particularly preferable when applied to an NC lathe or a lathe. In general, a bed 14 is disposed on a base 27 and a motor 4 such as a servo motor is provided. It is arranged. The bed 14 is provided with a head stock 1 constituting a headstock 50 via a head spacer 21 and a Z-axis slide 29 that reciprocates in the Z-axis direction. A saddle 30 is installed on the Z-axis slide 29. The saddle 30 is provided with an X-axis slide 28 that reciprocates in the X-axis direction. Although not shown, the X-axis slide 28 is provided with a tool post and a turret for attaching a cutting tool for cutting a workpiece. The headstock 50 is configured such that the position of the reference block 25 provided on the headstock 50 is adjusted by the adjustment block 24 provided on the head spacer 21 and is set on the head spacer 21 fixed to the bed 14 with high accuracy. Has been. In this embodiment, the power transmission means for transmitting the rotational driving force of the motor 4 to the quill 3 is a V-shaped belt applied to the pulley 6 attached to the quill 3 and the pulley 7 attached to the output shaft 53 of the motor 4. And the like. The power transmission means is not limited to a belt, but may be constituted by a gear transmission device depending on circumstances. Further, the head stock 1 is configured to be balanced by a weight 23.

  The headstock device of this machine tool is mainly provided at one end 52 of the quill 3 and the quill 3 having a hollow portion 12 constituting a main shaft that is rotatably supported on the mainshaft 50 via bearings 8 and 9. A motor 47 for rotationally driving a chuck 47 for attaching an attached work (not shown), a pulley 6 fixed to the other end 51 of the quill 3, and a pulley 6 via a belt 10 such as a V-belt. In particular, the configuration of the headstock 50 is characteristic. The belt 10 is hung on a pulley 7 attached to the output shaft of the motor 4 and on a pulley 6 fixed to the end of the quill 3. Accordingly, the rotational driving force of the motor 4 is transmitted to the quill 3 through the pulley 7, the belt 10, and the pulley 6. A belt 49 is put on the position pulley 58 fixed to the end of the quill 3, and rotation information of the quill 3 is input to the position coder 26 through the belt 49. The hollow portion 12 of the quill 3 functions, for example, as a passage through which a draw bar for opening and closing a chuck for gripping a workpiece is passed or a coolant is supplied. The drawbar is configured to be operated by a rotating cylinder 54 or the like attached to the end 51 of the quill 3.

  In the head stock apparatus of the machine tool, the head stock 50 is particularly composed of a spindle case 2 having a hollow portion 12 that rotatably supports the quill 3 via bearings 8 and 9, and an end portion on the chuck side of the spindle case 2. A flange 15 provided on the head 31 includes a head stock 1 fixed by tightening in the axial direction with a bolt 16 (first bolt), and a slit ring 5 fixed to the head stock 1 so as to be detachable. The slit ring 5 fixed to the stock 1 has a pulley-side end portion 32 of the spindle case 2 in a state where the inner peripheral surface 33 of the slit ring 5 is in contact with the outer peripheral surface 34 of the pulley-side end portion 32 of the spindle case 2. It is characterized by supporting.

  In the headstock device of this machine tool, the slit ring 5 is fixed to the headstock 1 by tightening the headstock 1 with bolts 17 (second bolts) in the axial direction with the quill 3 in an operating state. Further, as shown in FIG. 3 or FIG. 4, the split ring 5 includes a bolt 18 (third bolt) whose inner diameter is reduced with respect to the outer peripheral surface 34 of the spindle case 2. The ring 5 is fixed to the head stock 1 with bolts 18 in a state where the ring 5 is fastened to the outer peripheral surface 34 of the spindle case 2.

  The headstock device of this machine tool is split when there is no difference between the thermal expansion of the spindle case 2 and the thermal expansion of the headstock 1 in the operation state of the quill 3, that is, when there is no change in the thermal expansion difference. The ring 5 is fixed to the headstock 1 to support the end portion 32 of the spindle case 2, and the spindle case 2 has a double-supported structure with the slit ring 5 and the bolt 16 inserted into the flange portion 15, so Etc. should not occur. However, when the thermal expansion difference between the spindle case 2 and the head stock 1 fluctuates, if the slit ring 5 is fixed to the head stock 1, for example, the spindle case 2 and / or the head stock 1 may be bent. If this occurs, and the thermal processing difference between the spindle case 2 and the head stock 1 fluctuates, the slit ring 5 is removed from the head stock 1. .

  An example of the assembly for attaching the quill 3 to the headstock 1 will be described with reference to FIG. An end 52 on the chuck side of the quill 3 is provided with a locking flange 38 for locking by the front cover 35. Further, a screw hole 40 for attaching a face plate to which a work attaching chuck is mounted is formed on the end face of the end portion 52 of the quill 3. A screw 55 is formed on the outer peripheral surface of the quill 3 on the end 52 side, and a screw 56 is formed on the outer peripheral surface of the quill 3 on the end 51 side. In the quill 3, the bearing retainer 19 is fitted in contact with the locking flange portion 38, and the pair of bearings 8 and the spacer 45 are fitted in the outer peripheral surface of the quill 3, and the nut 55 is attached to the screw 55 on the end 52 side. 43 is screwed in and fixed with a set screw 44, and the bearing 8 is fixed to the quill 3. After attaching the bearing retainer 19, the bearing 8, the spacer 45, and the nut 43 to the outer peripheral surface of the quill 3, the quill 3 is inserted into the hollow portion 13 of the spindle case 2, and the bearing retainer 19 is inserted into the front end of the spindle case 2 by the bolt 36. Secure to the surface. Next, the spacer 59, the bearing 9, and the spacer 42 are fitted on the outer peripheral surface of the quill 3, and the nut 41 is screwed into the screw 56 on the end 51 side and fixed with the retaining screw 46, whereby the bearing 9 is fixed to the quill 3. Secure to. Further, the rear cover 20 is fitted to the outer peripheral surfaces of the nut 41 and the spacer 42, and the rear cover 20 is fixed to the rear end surface of the spindle case 2 with bolts 57. Further, the front cover 35 is locked to the locking flange portion 38 of the end 52 on the load side of the quill 3, and the front cover 35 is fixed to the bearing retainer 19 by the bolt 37. Next, the spindle case 2 attached to the quill 3 is inserted into the hollow portion 11 of the head stock 1, and the spindle case 2 is fixed to the head stock 1 with bolts 16. Therefore, the pulley 6 is attached to the end 51 of the quill 3 projecting rearward from the rear end surfaces of the headstock 1 and the spindle case 2. Further, a face plate or the like constituting the spindle unit 22 is attached to the screw hole 40 formed in the end face of the end portion 52 of the quill 3, and the workpiece is attached to a chuck or the like constituting the spindle unit 22. Of course.

  In the head stock apparatus of this machine tool, a slit ring 5 is particularly attached to the headstock 1 in a type in which a difference in thermal expansion does not occur between the headstock 1 and the spindle case 2. Therefore, after attaching the quill 3 to the head stock 1, the slit ring 5 is fixed to the head stock 1 as follows. First, the inner peripheral surface 33 of the slit ring 5 is fitted to the outer peripheral surface 34 of the spindle case 2 protruding from the rear end surface of the head stock 1, and as shown in FIGS. The slit ring 5 is fastened to the spindle case 2 by the bolt 18 so that the split portion 48 is close to the spindle case 2. Next, the slit ring 5 is fixed to the head stock 1 with bolts 17. Since the headstock device of this machine tool is configured as described above, the spindle case 2 is supported by the headstock 1 in a double-sided structure by means of bolts 16 inserted through the flange portion 15 and the slit ring 5. As a result, the quill 3 is supported by the headstock 1 in a double-sided structure.

  The headstock device of this machine tool is used for a machine tool such as a lathe for cutting a workpiece with a cutting tool, for example.

It is a front view which shows one Example of the headstock apparatus of the machine tool by this invention. It is a top view which shows the headstock apparatus of the machine tool of FIG. FIG. 2 is a partially enlarged front view showing a driving state of a motor and a head stock in the head stock apparatus of the machine tool of FIG. 1. It is a side view explaining the drive state of the motor and headstock in the head stock apparatus of the machine tool of FIG. It is sectional drawing which shows the principal part of the headstock apparatus of the machine tool by this invention.

1 Headstock (headstock)
2 Spindle case (headstock)
3 Quill (spindle)
4 Motor 5 Slot ring 6, 7 Pulley 8, 9 Bearing 10 Belt 11, 12, 13 Hollow part 15 Flange part 16 Bolt (first bolt)
17 bolts (second bolt)
18 bolt (3rd bolt)
33 inner peripheral surface 34 outer peripheral surface 51, 52 end

Claims (2)

A hollow quill that constitutes a main shaft that is rotatably supported by a headstock via a bearing, a chuck for attaching a work attached to one end of the quill, and a power transmission provided at the other end of the quill A machine tool provided with a tool post that reciprocates in the X-axis direction and the Y-axis direction for mounting a means, a motor that rotationally drives the power transmission means, and a tool for machining the workpiece;
The headstock includes a spindle case having a hollow portion for rotatably supporting the quill via the bearing, and a flange portion provided at an end portion of the spindle case by inserting the spindle case into the hollow portion. A head stock which is fastened and fixed in the axial direction by bolts, and a slit ring which is fixed to the head stock so as to be removable.
The slit ring fixed to the head stock is supporting the other end of the spindle casing inner circumferential surface of the slit ring in contact with the outer peripheral surface of the other end portion of the spindle case,
The slit ring is fastened to the outer peripheral surface of the spindle case by a third bolt having a reduced inner diameter with respect to the outer peripheral surface of the spindle case, and is tightened axially to the head stock by the second bolt. And a headstock device for a machine tool, wherein the headstock device is fixed to the headstock. The power transmission means for transmitting the rotational driving force of the motor to the quill comprises a pulley attached to the end of the quill, a pulley attached to the output shaft of the motor, and a belt hung on both pulleys. The head stock apparatus for a machine tool according to claim 1, wherein

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