JPH07285046A - Method and device for attaching tool to machine tool - Google Patents

Abstract

PURPOSE:To clean a main spindle tapered hole, a main spindle end surface, a tool tapered part and a tool end surface part when a two surface binding tool is attached to a main spindle tool attaching part. CONSTITUTION:During relative movements of a main spindle 2 and a tool 7 in an axial direction C, they are temporarily stopped in a middle position having a specified space between the tapered hole and end surface of a main spindle tool attaching part 8 and the tapered surface and end surface part of the tool 7, this stop state is continued for a specified time and during this period, cleaming air D is supplied through a space between the main spindle tool attaching part 8 and the tool 7 and stuck objects are blown off and cleaned. Then, the relative movements of the main spindle 2 and the tool 7 are resumed and a tool clamping operation is performed in a state where these are stuck to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changing method and apparatus for a machine tool, and more particularly, in a machine tool using a tool that is clamped in close contact with a taper hole and an end face of a spindle tool mounting portion. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool mounting method and an apparatus for cleaning the end surface of a tool mounting portion and the end surface portion of a tool during a tool changing operation.

[0002]

2. Description of the Related Art In a machine tool such as a machining center equipped with an automatic tool changer (hereinafter referred to as ATC), a taper portion (taper shank portion) of a tool is brought into close contact with a taper hole of a spindle tool mounting portion so as to be axially aligned. A tool that is clamped by being pulled is widely adopted. Such a tool is defined by JIS-B-6339 and JIS-B-6340 and is called "BT **" (hereinafter, referred to as BT tool). However, in recent years, there has been proposed a so-called "two-face restraint tool" in which the taper portion and the end surface portion of the tool are brought into close contact with both the spindle tapered hole and the spindle end surface. Compared with the BT tool, the two-face constraint tool has a merit that it can be rotated at high speed and a work (workpiece) can be machined with high accuracy because it is mounted on the spindle with higher accuracy.

[0003]

However, the fact that both the tool taper portion and the tool end surface portion are brought into close contact with the spindle taper hole and the spindle end surface pays attention to fine adhered matters such as dust and dust more than before. There is a need. However, conventionally, when the tool is attached to or detached from the spindle tool mounting portion, cleaning air is supplied from the rear of the spindle taper hole to remove minute deposits on the spindle taper hole and the tool taper portion. However, in the case of the two-face constraint tool, there is no method for efficiently cleaning the tool end face portion and the spindle end face. Therefore, in a two-face constraint tool that requires high precision in mounting, a tool may be clamped while a minute adhered substance is clamped between the end face of the tool and the end face of the spindle, which lowers the precision of mounting the tool.

The present invention has been made to solve the above problems, and cleans the spindle taper hole, the spindle end surface, the tool taper portion and the tool end surface portion when the two-face restraint tool is mounted on the spindle tool mounting portion. It is an object of the present invention to provide a tool mounting method and a device therefor in a machine tool that can be used.

[0005]

In order to achieve the above object, the method according to the present invention is such that a taper hole and an end surface of a spindle tool mounting portion provided at a front end of a spindle are provided with a taper surface and a tool end surface portion of a tool. A tool mounting method of a machine tool for mounting a tool so as to be in close contact, wherein when mounting the tool on the spindle tool mounting portion, a tool unclamping operation is performed and the tool is inserted into the spindle tool mounting portion. For this purpose, the spindle and the tool are relatively moved in the axial direction of the spindle, and in the course of this relative movement, once the taper hole and the end surface of the spindle tool mounting portion and the taper surface and the tool end surface portion of the tool are The spindle or the tool is stopped at an intermediate position having a predetermined gap between them, and this stopped state is continued for a predetermined time, and at least during this stop time, a cleaning pressure fluid is supplied to the spindle tool mounting portion. Through the gap between the hole and end surface of the tool and the tapered surface of the tool and the end surface of the tool, and blow off and clean the deposits adhering to the spindle tool mounting portion and the tool, and then the spindle. And the relative movement between the tool and the tool are restarted, and the tool clamping operation is performed in a state where the taper hole and the end surface of the spindle tool mounting portion and the taper surface and the tool end surface portion of the tool are in close contact with each other.

Further, in the tool mounting device for a machine tool according to the present invention, the tool is mounted so that the taper surface and the tool end surface portion of the tool can be closely attached to the taper hole and the end surface of the spindle tool mounting portion provided at the front end of the spindle. In a tool mounting device for a machine tool, a hollow shaft-shaped main shaft supported by a main shaft support and provided with a tool mounting portion at a front end, and a through hole of the main shaft, which is movable forward and backward in the axial direction of the main shaft. And a draw bar for engaging and clamping the engaged portion on the tool side when moved in a predetermined direction, the engaging portion for engaging and disengaging the engaged portion of the tool being formed on the spindle tool mounting portion side. A position provided on the spindle support and having a predetermined gap between the end face of the spindle tool mounting portion and the end face of the tool when the spindle and the tool are relatively moved to mount the tool on the spindle. Intermediate position to stop and position And positioning means, said drawbar,
Or, it is provided between the draw bar and the spindle, one side is connected to the spindle tool mounting portion, the other side is connected to the cleaning pressure fluid supply source, and the cleaning pressure fluid supply source supplies the cleaning fluid. A cleaning pressure fluid supply means for supplying a pressure fluid to the spindle tool mounting portion, and supplying the cleaning pressure fluid to the spindle and the tool stopped and positioned at a position having a predetermined gap, and The taper hole and the end surface of the spindle tool mounting portion and the taper portion and the end surface portion of the tool can be cleaned by passing through the gap.

According to another aspect of the present invention, there is provided a tool mounting device in which a tool is mounted so that a taper surface and a tool end surface portion of a tool are closely attached to a taper hole and an end surface of a spindle tool mounting portion provided at a front end of a spindle. In a tool mounting device of a machine tool for performing, a hollow shaft-shaped main shaft supported by a main shaft support and provided with a tool mounting portion at a front end, and a through hole of the main shaft so that the main shaft can move back and forth in the axial direction of the main shaft. A draw bar is provided on the side of the spindle tool mounting portion for engaging and disengaging the engaged portion of the tool, and for engaging and clamping the engaged portion on the tool side when moving in a predetermined direction. And a spindle arm provided on an exchange arm of the tool exchanging device, which abuts an end surface of the spindle support when the spindle and the tool are relatively moved to mount the tool on the spindle, And the tool end surface part It is provided between the projecting member for stopping and positioning in a position having a space and the draw bar, or between the draw bar and the main shaft, and one side is connected to the main shaft tool mounting portion and the other side is connected to a cleaning pressure fluid supply source. And a cleaning pressure fluid supply means for supplying the cleaning pressure fluid supplied from the cleaning pressure fluid supply source to the main spindle tool mounting portion, and the main spindle stopped and positioned at a position having a predetermined gap. The cleaning pressure fluid is supplied to the tool to pass through the gap so that the taper hole and the end surface of the tool mounting portion and the taper portion and the end surface portion of the tool can be cleaned.

[0008]

In the present invention, during the transition from the tool unclamped state to the tool clamped state, between the taper hole of the spindle tool mounting portion and the tool tapered surface, and between the end surface of the spindle tool mounting portion and the tool end surface portion. A gap is formed between them for a predetermined time. Therefore, if the cleaning pressure fluid is blown into the minute gap at a high speed for the predetermined time,
Dust such as chips attached to the spindle tool mounting portion and the tool is blown to the outside to be in a clean state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view of a spindle head that is a spindle support, FIG.
Is a cross-sectional view of a main part when cleaning the tool at an intermediate position, FIG. 3 is a flowchart showing the operation of this embodiment, FIG. 4 is a cross-sectional view of the tool unclamping state of the cylinder device, and FIG. Is.

A spindle head 1 shown in FIG. 1 is provided in a machine tool such as a machining center, and a spindle 2 is rotatably supported by bearings 3, 4 and 5 on the spindle head 1. The spindle 2 transmits a driving force to the spindle 2 via a built-in motor (not shown) in which a rotor and a stator are arranged between the spindle 2 and the spindle head 1, or a transmission member such as a belt, a pulley and a gear. It is rotationally driven by a motor (not shown). The front end 6 of the spindle 2 is provided with a spindle tool mounting portion 8 for detachably mounting the tool 7. The tool 7 is the gripped part 7
a is gripped by the grip of the exchange arm 60 of the ATC, a tool exchange operation is performed between the tool storage magazine (not shown) and the spindle 2, and the spindle is mounted on the spindle tool mount 8.

A through hole 9 formed in the direction of the axis C of the main shaft 2.
The drawbar 10 is inserted thereinto so as to be movable back and forth in the direction of the spindle axis C. The draw bar 10 is always biased rearward by a biasing member 11 which is a plurality of disc springs or coil springs. An engaging member is provided at the tip of the drawbar 10, which utilizes a plurality of balls 12 that can move in the radial direction and that grasps and pulls the engaged portion of the pull stud 15 that is fixed at the rear portion of the tool 7. . The engaging member, the draw bar 10, the urging member 11 and the like constitute a tool clamping means. Such a tool clamping means called a ball type pulling mechanism method is known and will not be described in further detail. Further, the tool clamping means may be a tool collet type tension mechanism type clamping means utilizing a collet as an engaging member.

As shown in FIGS. 1 and 2, the spindle tool mounting portion 8 is continuous with the spindle tapered hole 23 for receiving the tapered portion of the tool 7 and the opening end edge 24 of the spindle tapered hole 23, and the spindle axis line. It has a flat spindle end face 25 orthogonal to the C direction. The tool 7 is provided with a conical tool taper portion 26 and a flat tool end surface portion 27 which is continuous with the tool taper portion 26 and is perpendicular to the tool taper axis. 25, the tool taper portion 26,
The tool end face portions 27 are attached and detached so as to be in close contact with each other.

Next, when the spindle 2 and the tool 7 are provided on the spindle head 1 and the spindle 2 and the tool 7 are moved relative to each other to mount the tool 7 on the spindle 2, the end face 25 and the tool end face portion 27 of the spindle tool mounting portion 8 are The intermediate position positioning means for stopping and positioning at a position having a predetermined gap will be described. As shown in FIG. 4, the cylinder body 40 and the large cylinder cover 40a of the cylinder device 20 have an oil passage 47a, which is a pressure fluid passage that communicates with one large cylinder chamber 42a and the other large cylinder chamber 42b, respectively. 47b is formed. Cylinder body 4
0 and a large-diameter piston rod 4 fitted to the inner peripheral surface 41
3, an oil passage 46a communicating with one small cylinder chamber 45a for supplying pressure oil as a pressure fluid, and a ring groove 4
6c and an oil passage 46d are formed. An oil passage 46b communicating with the other small cylinder chamber 45b is formed in the small cylinder cover 43a. Oil passage 47a, 47
Each b is connected to a direction switching valve (solenoid valve) 50. The oil passages 46a and 46b are each connected to a direction switching valve (solenoid valve) 51. That is, the solenoid 5 is controlled by a control device (not shown).
The small-diameter piston rod 21 is moved to three-stage positions by exciting 3a and 53b to switch the direction of pressure oil supply of the direction switching valve. An oil passage that is supplied with pressure oil and has increased pressure is indicated by a symbol P. Reference numeral 48a is a pressure fluid supply source that is a supply source of pressure oil. In the present embodiment, the pressure fluid is described as the hydraulic oil set to a predetermined pressure, but other gas such as compressed air or a liquid set to a predetermined pressure may be used.

As shown in FIGS. 1, 2 and 4, the drawbar 10 and the small diameter piston rod 21 of the cylinder device 20.
During the attachment / detachment operation of the tool, especially when a predetermined gap is formed between the spindle taper hole 23 and the tool taper portion 26, and between the spindle end surface 25 and the tool end surface portion 27, A cleaning pressure fluid supply unit having the following configuration is provided in order to allow cleaning air D, which is a cleaning pressure fluid, to pass through at high speed to clean both tapered portions and both end surface portions.

Small diameter piston rod 2 of cylinder device 20
1 is fitted to the hollow inner peripheral surface 44 of the large-diameter piston rod 43, and a cleaning air passage (hereinafter referred to as an air passage) connected to a cleaning pressure fluid supply source 48b is provided at the center of the small-diameter piston rod 21. 31) is formed. Air passages 32, 33, and 35 are also formed in the drawbar 10. Rear end face 2 of small diameter piston rod 21 and draw bar 10
When they come into contact with each other, the air passage 31, the air passage 32, the air passage 33, the through hole 9 of the main shaft 2 and the outer periphery of the drawbar 10, and the air passage 35 communicate with each other. That is, when the small-diameter piston rod 21 of the cylinder device 20 comes into close contact with the rear end surface 22 of the draw bar 10, the cleaning air supplied from the cleaning pressure fluid supply source 48b is supplied to the air passages 31, 32, 3 and 3.
3, the through hole 9, the air passage 35, and the spindle tool mounting portion 8 in this order, and after passing through the gap between the spindle tapered hole 23 and the tool tapered surface 26, the gap between the spindle end surface 25 and the tool end surface 27 is passed. Passes through and is released into the atmosphere. The pressure of the cleaning air is preferably 0.4 to 0.6 MPa (4 to 6 Kgf / cm ² ) at the pressure of the cleaning pressure fluid supply source 48b. The cleaning air is compressed air, but is not limited to this and may be any clean gas.

A tool attaching / detaching operation for exchanging a tool will be described with reference to the flowchart of FIG. An example will be described in which the old tool mounted on the spindle tool mounting portion and the new tool stored in the tool storage magazine (not shown) are exchanged with each other. Automatic tool changer not shown (hereinafter, ATC
(Described)) is moved to the spindle tool mounting portion side, and one gripping portion of the replacement arm 60 grips the gripped portion 7a of the old tool 7 mounted on the spindle tool mounting portion.
This exchange arm 60 has a known mechanism of a twin arm type, and a new tool is held by the other holding portion. (Step 100)

Next, the cylinder device 20 is moved to the forward position. That is, the solenoid 5 of the direction switching valves 50 and 51
3a and 53b are excited to supply pressure oil to the other large cylinder chamber 42b and the other small cylinder chamber 45b. The large-diameter piston rod 43 and the small-diameter piston rod 21 move forward toward the main shaft 2 side, press the rear end surface 22 of the drawbar 10, and move the drawbar 10 forward against the biasing force of the biasing member 11. By moving the draw bar 10 to the forward end, the tool 7
Can be detached from the tool clamping means. (Step 1
05) The supply direction is switched by exciting the solenoid 48d of the direction switching valve 48c to supply the cleaning air.
(Step 110) The replacement arm 60 is moved forward by a driving body (not shown), and the old tool 7 is detached from the spindle tool mounting portion 8 (step 1
15). Steps 100 to 115 are the tool removing operation.

The replacement arm 60 is rotated 180 degrees to switch the positions of the old tool and the new tool. The new tool is positioned at a position facing the spindle tool mounting portion 8. (Step 120) Next, the cylinder device 20 is set to the neutral position. That is,
Excitation of the solenoid 53a of the direction switching valve 50 continues, but the solenoid 53b of the direction switching valve 51 is demagnetized and the supply direction of the direction switching valve 51 is switched by the spring 52b.
The other large cylinder chamber 42b and the one small cylinder chamber 45a
Supply pressure oil to the side. The large-diameter piston rod 43 maintains the advanced state, but the small-diameter piston rod 21 retracts in the direction away from the main shaft 2 (see FIG. 5). (Step 12
5) The replacement arm 60 is retracted to the spindle tool mounting portion 8 side. At this time, the pull stud 15 of the new tool comes into contact with the drawbar 10, and the backward movement of the replacement arm 60 is stopped (see FIG. 2). At this time, a minute clearance (for example, clearance dimension e = 0.1 mm) is formed in the axial direction between the tool end surface portion 27 of the new tool 7 and the spindle end surface 25. That is, a path through which cleaning air, which is a minute gap, passes is formed between the spindle taper hole 23 and the tool taper portion 26, and between the spindle end surface 25 and the tool end surface portion 27. (Step 130) This neutral state is maintained for a predetermined time (for example, 0.5 to 1 second), cleaning air is passed through to remove fine dust and other foreign matter, and the spindle taper hole 23 and the tool taper are removed. Part 2
6. Clean the spindle end face 25 and the tool end face portion 27. (Step 135)

Then, the cylinder device 20 is moved to the retracted position. That is, the solenoid 53a of the direction switching valve 50 is demagnetized, the supply direction of the direction switching valve 50 is switched by the spring 52a, and pressure oil is supplied to one large cylinder chamber 42a. That is, the large-diameter piston rod 43 and the small-diameter piston rod 21 respectively move to the retracted position and separate from the draw bar 10. The drawbar 10 is retracted by the urging force of the urging member 11, the new tool is retracted together with the replacement arm 60, and the tool taper portion is brought into close contact with the spindle taper hole and the tool end face portion is brought into close contact with the spindle end face. Further, the draw bar 10 retracts, and the engaging member grasps the engaged portion of the pull stud 15 of the new tool, and pulls and clamps in the axial direction. (Step 140) The solenoid 48d of the direction switching valve 48c is demagnetized, and the direction switching valve 48c is operated by the spring 48e so as to stop the supply of the cleaning air. (Step 145) The exchange arm 60 releases the grip of the new tool and moves in a direction away from the spindle tool mounting portion 8 (step 150). Steps 125 to 150 are the tool mounting operation.

Although the embodiment of the present invention has been described using the BT tool, the present invention is not limited to this. That is, a short hollow shank with flange (1/1
It may be a tool 7 called a 0 taper or a cylinder). Such a short hollow shank with a flange (hollow tool shank (HST)) is known from DIN standard 69893 or the like and will not be described here any further. Compared with the BT tool, only the shape of the engagement / disengagement portion with the tool, that is, the tool clamping means is different, and the other configurations are exactly the same.

FIG. 7 is a view showing still another embodiment of the present invention, which is an enlarged view of a main part when the tool changing operation is stopped at an intermediate position and corresponds to FIG. In the embodiment described above, the cylinder device 20 of the type having double cylinders and piston rods is used, and the tool 7 is temporarily stopped immediately before it comes into close contact with the spindle tool mounting portion 8 to clean both tapered portions and both end surface portions. A gap portion for forming is formed. However, in the present embodiment, each of the gaps is formed by providing the replacement arm 60 of the ATC with the protruding member 70 positioned to a predetermined size. The height of the protruding member 70 can be adjusted by a screw mechanism or the like, and in order to prevent the end surface portion 27 of the tool 7 from inclining with respect to the end surface 25 of the tool mounting portion, the protruding member 70 is provided at several positions. It is preferably provided. In the cylinder device 20 of this embodiment, the draw bar may be moved to the unclamp position and the clamp position,
The cylinder and piston rod may be single. That is, when the exchanging arm 60 is in the tool exchanging operation, the protruding member 70 and the spindle support end face 72 contact each other to form a gap portion for cleaning both tapered portions and both end face portions. The flow chart of this embodiment is almost the same as that of FIG. 3, but the step 125 for setting the cylinder device 20 to the neutral position is unnecessary.
In the drawings, the same reference numerals indicate the same or corresponding parts.

[0022]

Since the present invention is configured as described above, when mounting a two-face restraint tool having a structure in which the tapered surface and the end surface are in close contact with the tapered hole and the end surface of the spindle tool mounting portion at the same time, the spindle tool mounting portion is mounted. In addition to both taper parts, both end surface parts can be cleaned.

[Brief description of drawings]

1 to 5 are views showing an embodiment of the present invention,
FIG. 1 is a sectional view of the spindle head.

FIG. 2 is a cross-sectional view of essential parts when cleaning a tool at an intermediate position.

FIG. 3 is a flowchart showing the operation of this embodiment.

FIG. 4 is a cross-sectional view of a tool unclamped state of the cylinder device.

FIG. 5 is a sectional view of the cylinder device in a neutral state.

FIG. 6 is a view showing another embodiment of the present invention and is a cross-sectional view showing a state in which a short hollow shank with a flange is mounted.

7 is a view showing still another embodiment of the present invention, which is a cross-sectional view of a main part when the tool changing operation is stopped at an intermediate position, and is a view corresponding to FIG.

[Explanation of symbols]

 1 spindle head (spindle support) 2 spindle 6 spindle front end 7 tool 8 tool mounting part 9 through hole 10 drawbar 23 taper hole 25 end surface of tool mounting part 26 taper surface of tool 27 tool end surface part 48b cleaning fluid supply source 60 Exchange Arm 70 Projecting Member 72 End Face of Spindle Support C Spindle Axis D Cleaning Air (Cleaning Pressure Fluid)

Claims (3)

[Claims] 1. A tool mounting method for a machine tool for mounting a tool such that a taper surface and a tool end surface portion of a tool can be closely attached to a taper hole and an end surface of a spindle tool mounting portion provided at a front end of a spindle. When mounting the tool on the spindle tool mounting portion, a tool unclamping operation is performed, and in order to insert the tool into the spindle tool mounting portion, the spindle and the tool are relatively moved in the axial direction of the spindle. During the relative movement, once, the spindle or the tool is stopped at an intermediate position having a predetermined gap between the tapered hole and the end surface of the spindle tool mounting portion and the tapered surface and the tool end surface portion of the tool, This stopped state is continued for a predetermined time, and at least during this stopped time, the cleaning pressure fluid is supplied between the taper hole and end surface of the spindle tool mounting portion and the taper surface and tool end surface portion of the tool. Passing in between, blow off and clean the adhering matter attached to the spindle tool mounting part and the tool, then restart the relative movement of the spindle and the tool, the taper hole of the spindle tool mounting part A tool mounting method for a machine tool, wherein the tool clamping operation is performed in a state where the end surface and the taper surface of the tool and the tool end surface portion are in close contact with each other. 2. A tool mounting device of a machine tool for mounting a tool such that a taper surface and a tool end surface portion of a tool can be closely attached to a taper hole and an end surface of a spindle tool mounting portion provided at a front end of a spindle. A hollow shaft-shaped main shaft that is supported by the body and has a tool mounting portion at the front end, and a through hole of the main shaft that is movable back and forth in the axial direction of the main shaft. An engaging portion that engages and disengages with the engaging portion is formed, and a draw bar that engages with and clamps the engaged portion on the tool side when moved in a predetermined direction; When the spindle and the tool are relatively moved to mount the tool,
An intermediate position positioning means for stopping and positioning the spindle tool mounting portion end surface and the tool end surface portion at a position having a predetermined gap, the drawbar, or provided between the drawbar and the spindle, one side of which is A cleaning pressure fluid supply means for supplying the cleaning pressure fluid supplied from the cleaning pressure fluid supply source to the main spindle tool mounting section, the other side being connected to the cleaning pressure fluid supply source; The cleaning fluid is supplied to the spindle and the tool that are stopped and positioned at a position having a predetermined clearance, and the cleaning pressure fluid is passed through the clearance to form a taper hole and an end surface of the spindle tool mounting portion, and the tool. A tool mounting device for a machine tool, characterized in that the taper portion and the end surface portion of the can be cleaned. 3. A tool mounting device of a machine tool for mounting a tool so that a taper surface and a tool end surface portion of a tool can be closely attached to a taper hole and an end surface of a spindle tool mounting portion provided at a front end of a spindle. A hollow shaft-shaped main shaft that is supported by the body and has a tool mounting portion at the front end, and a through hole of the main shaft that is movable back and forth in the axial direction of the main shaft. An engaging portion that engages and disengages with the engaging portion is formed, and a draw bar that engages with and clamps the engaged portion on the tool side when moved in a predetermined direction, and is provided on the exchange arm of the tool exchanging device. Position where the spindle and the tool come into contact with the end surface of the spindle support when the spindle and the tool are relatively moved to mount the tool on the spindle, and the spindle tool mounting portion end surface and the tool end surface portion have a predetermined gap. Projection to stop and position Material and the draw bar, or provided between the draw bar and the spindle, one side is connected to the spindle tool mounting portion, the other side is connected to the cleaning pressure fluid supply source, this cleaning pressure fluid supply source The cleaning pressure fluid supplied from the cleaning pressure fluid is supplied to the spindle tool mounting portion, and the cleaning pressure is applied to the spindle and the tool stopped and positioned at a position having a predetermined gap. A tool mounting apparatus for a machine tool, characterized in that a fluid is supplied to pass through the gap, and the taper hole and the end surface of the tool mounting portion and the taper portion and the end surface portion of the tool can be cleaned.