JP4419131B2 - Machine tool spindle equipment - Google Patents

Description

  The present invention relates to a spindle device of a machine tool, and more particularly to a technique for coaxially connecting a spindle that rotates to machine a workpiece of a machine tool and a motor shaft that drives the spindle.

  In recent years, built-in motors with a wide range of output characteristics ranging from low-speed torque to high-speed and high-power are used for machine tools. By connecting the motor shaft and the main shaft without using a reduction / acceleration gear, the main shaft High speed and high output are achieved. As such a machine tool, a spindle device having a configuration in which a spindle and a motor shaft are directly connected has been proposed.

For example, in the spindle device described in Patent Document 1 (hereinafter referred to as the prior art), spindle claws and spindle grooves are alternately provided at three circumferential positions of the spindle joint portion of the spindle, while the motor shaft joint portion is provided in the joint portion of the motor shaft. Also, a motor shaft claw and a groove portion corresponding to the main shaft claw and the main shaft groove of the main shaft coupling portion are provided.
When the motor shaft joint and the main shaft joint are assembled, the motor shaft claw is inserted into the main shaft groove, and at the same time, when the main shaft claw is inserted into the motor shaft groove, the main shaft claw and the motor shaft claw There are six gaps along the circumferential direction between them, and a shielding member is inserted into each gap. The shielding member is made of a material having heat insulating properties and vibration proof properties, and is made of a flat plate having a thickness inserted into each of the gaps.
Therefore, since the main shaft and the motor shaft are coaxially connected to each other by a heat insulating and vibration-proof shielding member, large heat generation on the motor side is blocked by the shielding member, and the dynamic balance of the motor-side rotor becomes the main shaft. Since there is no direct influence, it is possible to obtain a spindle that can achieve high-speed and high-precision rotation with little temperature rise and little vibration.
In other words, in the main shaft device, when the main shaft and the motor shaft are connected, heat due to the temperature rise of the motor may be transmitted to the main shaft, and thermal displacement may be promoted from the direction of the main shaft. Because the dynamic balance directly affects the rotation accuracy of the main shaft and the vibration mode of the main shaft diameter becomes complicated, the above-described configuration makes it smaller, lighter, has less thermal displacement, and has less vibration of the main shaft at high speed. High-precision rotation can be performed.
Japanese Patent No. 2785691

By the way, in the above prior art, since the shielding member is sandwiched in the gap between the main shaft claw and the motor shaft claw, the main shaft and the motor shaft are connected, so there is a slight gap in the rotation direction due to the accuracy of each part. There are disadvantages that arise.
Also, when the shielding member is used, it performs a sufficient connecting function, but the shielding member is a simple flat plate, and the shielding member is compressed by the main shaft and the motor shaft. It may change to create a gap. Therefore, as the result of rattling between the spindle and the motor shaft, the accuracy when the spindle stops, the so-called positioning accuracy is reduced, or vibration is generated and the anti-vibration accuracy is reduced. There was a problem that decreased.
In addition, internal parts such as collets, push rods, and tool clamp springs are provided inside the main shaft and motor shaft. When these internal parts are pulled out for maintenance, the shielding member is as described above. Because it is in a compressed state, it falls into both the main shaft and the motor shaft, and it is necessary to take out the dropped shielding member one by one, which requires maintenance. There was a problem that extra work was required for the inspection work.

  The present invention has been made in consideration of such circumstances. The spindle device of a machine tool that can reliably connect the spindle and the motor shaft without rattling and can improve the machining accuracy. The purpose is to provide.

To achieve the above object, a spindle device of a machine tool according to the present invention includes a spindle having a plurality of spindle claws and a spindle groove that extend in the axial direction at the spindle joint portion and are alternately provided in the circumferential direction. A motor shaft having a motor shaft claw and a groove portion provided corresponding to the main shaft claw and the main shaft groove in the joint portion; and when the motor shaft claw is inserted into the main shaft groove and the main shaft claw is inserted into the groove portion, In a spindle device of a machine tool having a shielding member that is inserted into a plurality of circumferentially defined gaps between the spindle claw and coaxially connecting the spindle and the motor shaft, the shielding member is a gap A first member and a second member sandwiched in contact with each other along the circumferential direction, and the contact surfaces of the first member and the second member are tapered surfaces inclined with respect to the radial direction of the motor shaft. Features.
According to the present invention, when the first member and the second member of the shielding member are inserted into the gap between the motor shaft claw and the main shaft claw that are fitted to each other, both the first member and the second member are Since the wedge action is generated by the tapered surfaces of the first member and the second member that are pressed tightly into the gap, the adjacent motor shaft claws and the spindle claws are closely fixed in the circumferential direction. .

Further, the first member is preferably provided with a hooking portion that engages with the outer peripheral portion of either the main shaft claw or the motor shaft claw at the position inserted in the gap.
As a result, when the second member is pulled out from the state where both the first member and the second member are inserted into the gap, the first member is caught by either the main shaft claw or the motor shaft claw. Therefore, there is no possibility that the first member falls into both the main shaft and the motor shaft.
Further, both ends of the first member and the second member may be sandwiched between the cover members, so that the first member and the second member can be prevented from being displaced in the axial direction from each other when being pushed in. The contact state between the member and the second member can be kept good.
Also, a fixing ring that covers the main shaft claw and the motor shaft claw that are fitted to each other and the first member and the second member that are sandwiched in the gap is disposed, and the first member or the second member is disposed on the fixing ring. A pushing member that is pushed into the gap is supported so as to be able to advance and retreat in the radial direction.
By pushing the second member or the first member with the pushing member, the first and second members in the gap can be closely fitted and fixed in a wedge shape, and the occurrence of rattling can be reliably prevented.

  According to the present invention, when the first member and the second member of the shielding member are inserted into the gap, the motor shaft claw and the spindle claw can be closely and firmly fixed to each other in the circumferential direction by performing a wedge function. The main shaft and the motor shaft can be reliably connected without causing backlash in the rotational direction, and the processing accuracy can be improved. In addition, the stopping accuracy of the main spindle can be maintained with high accuracy, and vibration isolation can be maintained.

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are views showing a spindle device of a machine tool according to an embodiment of the present invention.
In FIG. 1, the spindle device 10 of the machine tool includes a motor 11 as a drive source and a spindle 30 (see FIG. 3) to be described later driven by the motor 11.
The motor 11 has a motor shaft 14 that is rotated about its axis by a rotor 12 and a stator 13. A cylindrical rotor 12 is fixed to the outer peripheral surface of the motor shaft 14 in the axial direction, and the rotor 12 is inserted through the stator 13. The stator 13 is fixed to the inner peripheral surface of the housing 16 formed in a substantially cylindrical shape by shrink fitting or the like, and is inserted so that the rotor 12 faces the inside. The stator 13 is provided with a coil 15, and when the coil 15 is energized, a magnetic circuit is formed between the stator 13 and the rotor 12, so that the motor shaft 14 rotates about the axis.

Both sides of the motor shaft 14 are supported by end plates 18 and 18 via bearings 17, respectively. A housing 16 is attached between the end plates 18 and 18, and a passage 19 for cooling the motor 11 is provided on the peripheral wall of the housing 16. A plurality of passages 19 are provided on the peripheral wall of the housing 16 in parallel with the motor shaft 14 and at predetermined intervals along the circumferential direction.
Further, the housing 16 is provided with a groove 20 for communicating the adjacent passages 19, and the end plate 18 is provided with supply holes 21 and discharge holes (not shown) connected to the passages 19.

Furthermore, the outer wall of the end plate 18 and the housing 16 is provided with a covering wall 22 made of a substantially octagonal cylinder that covers them. When the coil 15 of the motor 11 generates heat, the heat escapes from the upper air hole (not shown) provided in the upper part of the housing 16 to the outside of the covering wall 22 or is provided downward of the housing 16. The air enters the inside of the covering wall 22 from the lower air hole 23 and is discharged to the outside by the cooling fan 25 through the duct 24.
The passage 19 also serves as a passage for the cooling medium. In the motor 11 having a large calorific value, the cooling medium supplied from a refrigerator (not shown) cools the housing 16 and is then cooled by a fan cooler before freezing. On the other hand, on the main shaft 30 to be described later, a main shaft jacket and a spindle head (not shown) are cooled and returned.

A joint portion 26 is provided at one end of the motor shaft 14 of the motor 11 as shown in FIG. 2, while a main shaft joint portion 31 is provided at one end of the main shaft 30 as shown in FIG. The main shaft joint portion 31 and the joint portion 26 are assembled as shown in FIGS. 4 and 5.
That is, as shown in FIG. 2, the joint portion 26 of the motor shaft 14 has a cylindrical shape with a reduced outer diameter, and a motor shaft claw 27 and a groove portion 28 are provided at the tip thereof. The motor shaft pawl 27 extends at a predetermined length along the direction of the motor shaft 14 in the joint portion 26, and is provided with three protrusions at predetermined intervals along the circumferential direction. The groove portion 28 is on the same circumference as the motor shaft claw 27 in the joint portion 26, and is formed by cutting between the motor shaft claws 27 and 27. The groove 28 is formed so that the circumferential length is larger than the circumferential length of the motor shaft pawl 27.
Accordingly, the motor shaft claws 27 and the groove portions 28 are alternately provided in the circumferential direction in the joint portion 26 of the motor shaft 14.

  On the other hand, as shown in FIG. 3, the main shaft joint portion 31 of the main shaft 30 is formed in a cylindrical shape having the same inner diameter and the same outer diameter as the joint portion 26, and a main shaft claw 32 and a main shaft groove 33 are formed at the tips thereof. ing. The main shaft claw 32 and the main shaft groove 33 are formed corresponding to the motor shaft claw 27 and the groove portion 28 of the motor shaft 14. As shown in FIGS. 3 and 5, the main shaft joint portion 31 is formed such that its base side is shorter in the axial direction than that of the joint portion 26 of the motor shaft 14.

  The motor shaft 14 and the main shaft 30 are configured such that when the joint portion 26 and the main shaft joint portion 31 are inserted into each other, that is, the motor shaft claw 27 is inserted into the main shaft groove 33 and the main shaft claw is inserted into the groove portion 28. As shown in FIG. 4, when the shaft 32 is inserted, the motor shaft claw 27 and the main shaft claw 32 are alternately positioned along the circumferential direction, and a gap 35 is provided between the motor shaft claw 27 and the main shaft claw 32. Are each defined. The main shaft 30 and the motor shaft 14 are coaxially connected to each other by inserting a shielding member 40 described later into the gap 35.

  As shown in FIGS. 4 and 5, the shielding member 40 of this embodiment includes a first member 41 and a second member 42 that are sandwiched in a gap 35 defined between the motor shaft claw 27 and the main shaft claw 32. I have.

As shown in FIG. 6, the first member 41 is formed in a substantially L shape by forming a hooking portion 41 b extending in the crossing direction on the upper portion of the plate-like body 41 a. At the time of insertion into the gap 35 between the spindle claws 32, the hook portion 41 b is hooked on the spindle claws 32.
As shown in FIG. 6, the second member 42 has a substantially flat plate shape, and when the hook portion 41 b of the first member 41 is hooked on the main shaft claw 32, the first member 41 and the motor shaft claw 27 is inserted between the first member 41 and the first member 41.

In that case, when the first member 41 and the second member 42 are inserted into the gap 35 between the main shaft claw 32 and the motor shaft claw 27 as shown in FIG. Tapered surfaces 43 and 44 having a predetermined angle are provided so as to be inclined with respect to the radial direction of the shaft 14. In other words, the tapered surface 44 is formed in a shape that gradually becomes thinner from the outer end (outer diameter) side to the distal end (inner diameter) side of the second member 42, and the tapered surface 43 corresponds to the tapered surface 44. The first member 41 is formed to be thick from the outer end side to the tip end side. The first member 41 and the second member 42 are formed of a material having heat insulating properties and vibration proof properties, and are made of, for example, a synthetic resin in this example, but may be other than that.
As shown in FIGS. 6 and 7, inclined portions 41 c are provided on both sides of the first member 41 in the axial direction.

  Further, the shielding member 40 includes a pushing member 45 and a fixing ring 48. The pushing member 45 is attached to a fixing ring 48 that covers the periphery of the motor shaft claw 27 and the main shaft claw 32 so as to be movable in the radial direction. For example, the first screw 46 that pushes the second member 42 by rotating. And a second screw 47 that locks the first screw 46 and a double screw. Therefore, as shown in FIG. 6, the heads of the first screw 46 and the head of the second screw 47 are respectively provided with cross holes 46a and 47a for inserting a screwdriver (not shown) as a tool. Yes.

  The fixing ring 48 is sized to pass through the motor shaft claw 27 and the main shaft claw 32, and the first member 41 and the second member inserted into the gap 35 between the motor shaft claw 27 and the main shaft claw 32 are arranged in the outer circumferential direction. The first member 41 and the second member 42 are formed of the same material as the first member 41 and the second member 42. Around the fixing ring 48, a pusher member hole (not shown) is provided in a radial direction at a position corresponding to the pusher member 45, and a first screw is provided on the inner periphery of the pusher member hole. A female screw portion 49 corresponding to a male screw portion (not shown) of 46 and the second screw 47 is engraved, and a space large enough to accommodate the first member 41 and the second member 42 is formed on the inner periphery thereof. A storage groove 50 is defined.

  Also, covers 51 are attached to both ends of the fixing ring 48 in the axial direction by bolts 52. As shown in FIG. 5, the cover 51 is formed in an annular shape having a size that allows the main shaft joint portion 31 and the joint portion 26 to be inserted by a thin plate, and when attached to both ends of the fixing ring 48, respectively. However, the first member 41 and the second member 42 are sandwiched in the axial direction. Therefore, the cover 51 has a smaller inner diameter than the inner diameter of the fixing ring 48. When the cover 51 is attached to the fixing ring 48, the inner diameter side is outward from the gap 35 with respect to the first member 41 and the second member 42. In contact with the protruding part.

  Accordingly, the spindle device 10 includes the motor 11, the spindle 30, and the shielding member 40, and the shielding member 40 is inserted into the gap 35 between the motor shaft claw 27 and the spindle claw 32 and the first member 41 and the first member 41. Two members 42, a pushing member 45 that pushes the second member 42 in the centripetal direction, and supports the pushing member 45 so as to be movable in the radial direction, while the motor shaft claw 27, the spindle claw 32, the first member 41, the second member 42, and a cover 51 that is attached to both ends of the fixing ring 48 in the axial direction and sandwiches both the first member 41 and the second member 42.

Since the main shaft device 10 of this embodiment is configured as described above, when the motor shaft 14 of the motor 11 and the main shaft 30 are connected, it is performed as follows.
When connecting, both covers 51 are previously removed from the fixing ring 48, and only the first screw 46 of the push-in member 45 is screwed into the female screw portion 49 of the fixing ring 48. Yes.
And the joint part 26 of the motor shaft 14 is inserted by the operator into the inside of the right cover 51 and the fixing ring 48 shown in FIG. 51 and the fixing ring 48 are shifted, and the spindle joint 31 is inserted into the left cover 51 shown in FIG. 5 and the left cover 51 is shifted to the base side thereof. The joint portion 26 of the motor shaft 14 is combined with each other.
That is, by inserting the motor shaft claw 27 of the motor shaft 14 into the main shaft groove 33 of the main shaft 30 and inserting the main shaft claw 32 into the groove portion 28 of the motor shaft 14, as shown in FIG. Thus, six gaps 35 along the circumferential direction are defined between the first and second members 27.

  Next, after both the motor shaft 14 and the main shaft 30 are rotated by an operator and any one of the gaps 35 is positioned upward, the hooking portion 41b of the first member 41 is moved in the gap 35. The first member 41 is inserted by hooking on the outer peripheral portion of the main shaft claw 32, and then the second member 42 is inserted between the first member 41 and the motor shaft claw 27. At that time, the taper surface 44 of the second member 42 is inserted into contact with the taper surface 43 of the first member 41.

  After inserting the first member 41 and the second member 42 into one gap 35 in this way, the next gap 35 is positioned in the same manner, and the first member 41 and the second member are placed in the gap 35. The insertion of both the members 41 and 42 into all the gaps 35 is completed by repeating the sequential insertion of 42 in the same manner as described above.

Thereafter, the fixing ring 48 on the main shaft coupling portion 31 is shifted to the first member 41 and the second member 42 side, and the portions projecting outward from both the members 41 and 42 are stored in the storage groove 50 of the fixing ring 48. Position so that.
Next, when the first screw 46 is rotated from one of the pressing member holes of the fixing ring 48 using a screwdriver (not shown) as a tool and the first screw 46 is moved forward in the inner diameter direction, the first screw 46 is moved. As the second member 42 is moved in the radial direction with the first member 41 being in contact with the first member 41, both the first member 41 and the second member 42 are connected to the motor shaft claw 27 and the main shaft. It is pushed tightly into the gap 35 between the claws 32. As a result, a wedge action occurs between the first member 41 and the second member 42, so that the adjacent motor shaft claw 27 and main shaft claw 32 are firmly fixed to each other in the circumferential direction.

Hereinafter, the wedge action of the first member 41 and the second member 42 by the first screw 46 is performed in each gap 35, whereby the motor shaft claw 27 and the spindle claw 32 are firmly fixed to each other in the circumferential direction. The motor shaft 14 and the main shaft 30 are coaxially connected to each other.
After the motor shaft 14 and the main shaft 30 are connected in this way, the second screw 47 is turned into each of the pushing member holes of the fixing ring 48 by a screwdriver, and the tip of the second screw 47 is inserted into the first screw 46. The first screw 46 is locked by pressing against the head.

  Thereafter, the cover 51 on the main shaft 30 side and the cover 51 on the motor shaft 14 side are shifted to the fixing ring 48, and these covers 51 are respectively attached to both ends of the fixing ring 48 in the axial direction by bolts 52. Both the first member 41 and the second member 42 are sandwiched in the axial direction, and the process ends.

According to this embodiment, in the gap 35, the first member 41 of the shielding member 40 is inserted by engaging with the main shaft claw 32, and the second member 42 is inserted between the first member 41 and the motor shaft claw 27, Since the second member 42 is moved in the centripetal direction (rotation axis O direction) by the push-in member 45, the first member 41 and the second member 42 are pushed into the gap 35, and the wedge function is achieved. The motor shaft claw 27 and the main shaft claw 32 can be firmly fixed to each other in the circumferential direction.
In addition, the fixing ring 48 covers the first member 41, the second member 42, the main shaft claw 32, and the motor shaft claw 27 from the outer peripheral direction, and supports the push-in member 45 so as to be movable back and forth with respect to the second member 42. The pushing member 45 can be accurately pushed into the second member 42.

Therefore, unlike the prior art in which a simple flat shielding member is inserted in the gap, it is possible to prevent the backlash between the motor shaft 14 and the main shaft 30 from occurring in the rotation direction, and therefore the processing accuracy can be made high. In addition, it is possible to prevent the accuracy of stopping the main shaft 30 from being lowered and to prevent the occurrence of vibrations, so that the positioning accuracy can be maintained well.
And since such the 1st member 41 and the 2nd member 42 are formed with the material which has heat insulation and vibration-proof property, it suppresses that the heat by the temperature rise of the motor 11 is transmitted to the main shaft 30, There is little thermal displacement with respect to the main shaft 30, and there is little vibration of the main shaft 30, and high-speed and high-precision rotation can be performed.

Further, since the hooking portion 41b provided at the outer end of the first member 41 is engaged with the main shaft claw 32, when the first member 41 and the second member 42 are inserted into the gap 35, When the second member 42 is pulled out, the first member 41 remains in the state of being caught by the main shaft claw 32, and therefore the first member 41 may fall into both the shafts of the motor shaft 14 and the main shaft 31. There is no. Therefore, no extra work is required during maintenance and inspection of the internal parts provided inside the main shaft 30 and the motor shaft 14.
Therefore, as a result of reliably connecting the main shaft 30 and the motor shaft 14 without any backlash in the rotational direction, the stop accuracy of the main shaft 30 can be maintained with high accuracy, and vibration isolation can be maintained. In addition to improving machining accuracy, maintenance and inspection can be performed smoothly.

When the covers 51 are attached to both sides of the fixing ring 48, the first member 41 and the second member 42 can be prevented from being displaced in the axial direction by the respective covers 51. As a result, the contact state between the first member 41 and the second member 42 can be kept good, the wedge function can be kept good, and the reliability of the connection between the main shaft 30 and the motor shaft 14 can be further improved. Can be increased.
In addition, the push-in member 45 is composed of a double screw including a first screw 46 that moves the second member 42 and a second screw 47 that is locked to prevent the first screw 46 from being loosened. The wedge function can be maintained well.

  Further, in the above-described embodiment, the hook portion 41b of the first member 41 is easily hooked on the main shaft claw 32. Instead, the first member 41 is hooked on the motor shaft claw 27. However, similar effects can be obtained. Accordingly, in the present invention, the first member and the second member may be in the opposite form. In short, the main shaft joint portion and the motor shaft joint portion are tightly connected by inserting the two members into the gap. I can do it.

It is sectional drawing of the motor which shows the spindle apparatus of the machine tool which concerns on one embodiment of this invention. It is a perspective view which shows the coupling part of the motor shaft of the motor in FIG. It is a perspective view which shows a main shaft coupling part. It is a figure which shows the state by which the shielding member was assembled | attached to the clearance gap between the main shaft nail | claw of a main shaft coupling part, and the motor shaft nail | claw of a motor shaft, Comprising: It is an enlarged view for description seen from the cut surface orthogonal to an axial direction. It is the sectional view on the AA line of FIG. It is a disassembled perspective view which shows a shielding member and a pushing member. It is a top view for explanation of the 1st member and the 2nd member equivalent to the BB arrow of Drawing 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main shaft apparatus 11 Motor 14 Motor shaft 26 Motor joint part 27 Motor shaft claw 28 Groove part 30 Main shaft 31 Main shaft joint part 32 Motor shaft claw 33 Main shaft groove 35 Crevice 40 Shielding member 41 First member 41b Hook part 42 Second member 43, 44 Tapered surface 45 Push-in member 48 Fixing ring 51 Cover

Claims (4)

A main shaft having main shaft claws and main shaft grooves each extending in the main shaft joint portion along the axial direction and alternately provided in the circumferential direction;
Motor shafts each having a motor shaft claw and a groove provided in a joint portion corresponding to the main shaft claw and the main shaft groove;
When the motor shaft claw is inserted into the main shaft groove and the main shaft claw is inserted into the groove portion, the motor shaft claw is inserted into a plurality of gaps defined in the circumferential direction between the motor shaft claw and the main shaft claw, In a spindle device of a machine tool provided with a shielding member that coaxially connects a motor shaft,
The shielding member includes a first member and a second member that are held in contact with each other along a circumferential direction in a gap, and the contact surfaces of the first member and the second member are inclined with respect to the radial direction of the motor shaft. A spindle device of a machine tool characterized by a tapered surface. The spindle device of the machine tool according to claim 1,
A spindle of a machine tool, wherein the first member is provided with a hook portion that engages with an outer peripheral portion of either the main shaft claw or the motor shaft claw at a position inserted in the gap. apparatus. The spindle device of the machine tool according to claim 1 or 2,
A spindle device for a machine tool, wherein both ends of the first member and the second member are sandwiched between cover members. In the spindle device of the machine tool according to any one of claims 1 to 3,
A fixing ring that covers the main shaft claw and the motor shaft claw that are fitted to each other and the first member and the second member that are sandwiched in the gap is disposed, and the fixing ring includes the first member or the second member. A spindle device for a machine tool, characterized in that a pushing member for pushing the screw into the gap is supported so as to be able to advance and retreat in the radial direction.

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