JPH05277903A - Main spindle position identifying device - Google Patents

Abstract

PURPOSE:To reduce the number of limit switches used for a spindle position identifying device without marring the reliability of the device and achieve a small size around a spindle head and a wireless design. CONSTITUTION:In a machine tool which clamps and unclamps a spindle tool by moving a W axis to a tool-unclamped area behind a usual stroke area, a W-axis position detecting limit switches LS1-LS4 are used with a corresponding dog fitting plate for original point return identification (LS1), usual stroke area identification (LS2), tool unclamping identification (LS3) and +/- overtravel detection (LS4). When overtravel is reset, directional judgement is also made from the LS2, LS3 detection signals for the spindle tool to be fed and driven only to a W-axis feed and drive at allowable direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a clamp for a spindle tool,
The present invention relates to a device for confirming a spindle position in a machine tool that uses a W axis that moves a spindle head in a spindle axis direction for unclamping.

[0002]

2. Description of the Related Art FIG. 7 is a front view of a portal machine tool 1 equipped with a spindle position confirmation device, FIG. 8 is a side view thereof, and FIG.
Shows an enlarged cross-sectional schematic view of the spindle head portion.
The X, Y, Z axes and the A, C and W axes are defined by the following description. That is, the Z-axis is the linear motion feed shaft in the direction perpendicular to the work mounting surface, the X-axis is the feed shaft that moves the table in the horizontal direction in the plane orthogonal to the Z-axis, and the Y-axis is
The linear motion feed axis in the direction orthogonal to the Z axis and the X axis and the A axis are X
A rotary feed axis around an axis parallel to the axis, a C axis is a rotary feed axis around an axis parallel to the Z axis, and a W axis is an auxiliary linear motion feed axis parallel to the Z axis (A and C axes are at home positions). If located),

2 is a bed, 3 is supported by the bed 2 and X
A table that slides in the axial direction, the upper surface of which is a horizontal plane, and the work is fixed to the plane. Columns 4 and 5 are provided on both sides of the table 3 in a pair in a plane orthogonal to the X axis, and the upper ends of the columns are connected to each other so that the cross beam 6 is horizontally installed and connected. Forming machine.
A saddle 7 is supported by the cross beam 6 and is slidable along the cross beam 6 in the Y-axis direction. 8 is
A ram provided on the saddle 7 slides on the saddle 7 in the Z-axis direction. 9 is a C-axis base integrally formed with the ram 8 at the bottom thereof,

Reference numeral 10 denotes an A-axis base which is rotatably supported on the C-axis base 9 by a bearing, and the base is rotatable with respect to the C-axis base 9 in the C-turning direction by ± (180 + α) °. 11 is a W-axis base supported by bearings on the A-axis base 10,
The base 11 is ± with respect to the A-axis base 10 in the A turning direction.
It is mounted so that it can rotate (90 + α) °. Reference numeral 12 denotes a spindle head, which is fitted and supported by a W-direction linear guide 13 provided on the W-axis base 11 so as to be linearly movable in the W-direction. Here, the W direction is parallel to the axial direction of the spindle 15 supported by the spindle head 12.

In particular, referring to FIG. 9, this figure shows an enlarged cross-sectional schematic view in the vicinity of the spindle head 12 in the portal machine tool,
In the figure, the W-axis base 11 is provided with a stopper arm that blocks one direction end of the W-direction linear motion guide 13 provided on the base.
14 protrudes, and the tip end thereof extends until it intersects with the center line of a spindle 15 with a built-in motor supported by a bearing on the spindle head 12. On the other hand, a drawbar 16 having a collet portion at its tip is fitted to the central axis of a spindle 15 supported by the spindle head 12, and a plurality of disc springs 18 are fitted to the rear end of the drawbar 16. As a result, the drawbar 16 is always pulled in the direction of the main axis (upward in the figure) to constantly generate a diametrical tightening force on the collet portion of the drawbar 16, and the shank of the tool 17 is fixed thereto. I am trying.

Therefore, when the spindle head 12 described above moves extremely upward (to the tool unclamp area) in the figure along the W direction linear guide 13 provided on the W shaft base 11, The rear end of the drawbar 16 attached to the main shaft 15 hits against the end of the stopper arm 14 of the W-axis base 11,
Then, the group of disc springs 18 which applies a tensile force to the draw bar 16 is pressed. As a result, the force pulling the draw bar 16 in the axial direction disappears and the tightening force at the front end opening disappears, so the tool 17 is removed from the collet portion of the draw bar 16 (at that time, if the ram 8 is lowered synchronously, Spindle
15 vertical positions can be fixed). During machining, the spindle head 12 moves by the A or C axis,
It turns in various directions, but when changing tools, X,
Needless to say, the alignment is performed so that one of the Y and Z axes is parallel to the W axis. Here, the W axis and the Z axis are parallel.

In this state, if a new tool is inserted into the collet part and the spindle head 12 is gently moved downward in the W direction (as shown in the figure), the tension force of the Belleville springs 18 group will be increased again. Upon recovery, the spindle 15 will secure the new tool in its opening. From the above description, tool exchange in the machine of that type is possible only when the spindle head 12 moves in the W direction, particularly when the spindle head is located in a specific area on one side of the moving area. It is understood that In short, the tool unclamping region exists outside the W-axis normal stroke region of the spindle head. Therefore, when exchanging tools for the spindle, it becomes necessary to detect in advance the position of the spindle head 12 (W axis) in the movement area.

Therefore, in the conventional apparatus, referring to FIG. 10, a group of _seven limit switches LS _{1 to} LS 7 as shown in the figure on the W-axis base 11 side and the limit switch (LS) on the spindle head 12 side are shown. The dog attachment plate 20 corresponding to each switch (hereinafter referred to as a switch) and provided with each dock for operating the switch is attached, and each spindle dock 12 moves in the W direction with respect to the W axis base 11 in response to each dock. There as stepping on some one, or at the same time the switch LS ₁ ~LS _7, whereby W-axis position of the spindle head 12, or occupies unclamping region of the tool, either by over-travel, in which It is possible to determine in which direction the spindle head should be returned.

That is, the spindle head 12 with respect to the W-axis base 11
According to the position in the W direction of (1) Checking the clamped and unclamped state of the tool,
(LS ₃ ', LS ₅ ) (2) Stroke limit during normal operation,
(LS ₂ ') (3) Judgment of escape direction when overtravel is released, (LS ₄ ', LS ₆ , LS7 ₇ ) (4) It is necessary to judge whether to stop the tool clamping or unclamping operation in the manual mode. There are 7 switches for each function to detect the presence or absence of a dog for displaying each function, and in the conventional device, 7 switches are installed on the W-axis base 11, and an electric wire for transmitting a signal from each switch is also provided. Since the wiring is connected and wired according to the number of switches, the wiring around the W-axis base itself becomes complicated, and the area around the W-axis base becomes considerably large, which is not preferable for operation and control.

FIG. 10 is a schematic diagram of the above-described known spindle head position confirming device. In the figure, 11 is a W-axis base, 19 is a 7-series switch LS ₁ ′ to LS installed on the W-axis base 11. _{At 7} ,
Among them, the LS ₁ 'switch is for home return detection, the LS ₂ ' switch is for stroke limitation, the LS ₃ 'switch is for unclamp confirmation, and the LS ₄ ' switch is for
+ And-direction overstroke detection, LS ₅
Is for clamp confirmation, LS ₆ is for + direction discrimination and L
S ₇ is used for one-way discrimination, respectively. Therefore, a pair of electric wires is connected to each functional switch. Reference numeral 12 is a spindle head, and a dog mounting plate 20 carrying a dog group of 7 articles for displaying a required function corresponding to each switch is fixed to the spindle head, and the mounting plate 20 is integrated with the spindle head 12. Is provided so as to be slidable in the W arrow direction with respect to the W-axis base 11.

In the drawing, the distance from the horizontal line connecting the switch positions to the lower side of the dog (eg, corresponding to the switch LS ₄ 'or LS ₇ ) protruding near the upper edge of the mounting plate 20 is, for example, Of the normal stroke area of the spindle head 12 (machining area by a tool), from the horizontal line to the upper side of the dog (eg, corresponding to the switch LS ₄ 'or LS ₆ ) protruding near the lower edge of the mounting plate 20 , The longer spacing indicates the tool unclamping area. As described above, since the apparatus has a dedicated spindle position confirmation switch for each function, the size around the W axis is considerably large and the number of wiring lines is unavoidable.

[0012]

SUMMARY OF THE INVENTION Therefore, according to the present invention, the number of switches to be used is greatly reduced by utilizing the position confirmation for each judgment and the switch signals for up to four kinds of control judgments. In addition to realizing highly reliable individual operation, it is intended to realize miniaturization around the W-axis base and wire saving.

[0013]

In order to achieve the above-mentioned object, the present invention has the respective constituent features as described below. (1) A spindle is supported in the spindle head, a draw bar is inserted through the spindle, and a collet part for holding a tool is provided at the tip of the draw bar, and the draw bar is always biased rearward to tighten the collet part. Machine tool that clamps the tool, moves the draw bar forward against the biasing force, releases the collet, and unclamps the tool.
Axis, Y axis, Z axis and at least 4 linear motion feed axes of W axis that can be aligned in parallel with any one of the X, Y and Z axes, and the spindle head is a W axis base The upper part is driven by the W axis so as to be parallel to the axis of the main axis, and the W axis base is at least one of the X axis, the Y axis, and the Z axis, and is parallel to the W axis. An abutting portion that is driven by a shaft and abuts on the W-axis base to abut the rear end of the drawbar and press the drawbar forward.
Only in the unclamp mode, the W axis can be moved from the rear stroke end of the normal stroke area to the tool unclamp area further rearward, and the drawbar rear end and the abutting portion of the W axis base abut,
In the position confirming device for the spindle moving in the W-axis direction, which is configured to move the draw bar forward against the biasing force, release the collet portion to unclamp the tool,

At least three limit switches for detecting relative movement positions in the W-axis direction between the spindle head and the W-axis base and respective dogs corresponding thereto are provided, and the three limit switches are provided for the W-axis. LS ₂ for detecting the rear stroke end position of the normal stroke region, LS ₃ for detecting the tool unclamp position of the tool unclamp region, and the overtravel detection position in front of the normal stroke region and the tool unclamp region. LS ₄ for detecting the rear overtravel detection position, and when the limit switch LS ₄ operates to detect overtravel, the detection signals of the limit switches LS ₂ and LS ₃ are also received to release the overtravel. At the same time, a structure is provided which has a direction determining means for driving the W-axis only in the direction in which the W-axis can be driven. Spindle position confirmation device, characterized in that the.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the device of the present invention will be described below with reference to the drawings. However, each member constituting this embodiment is arbitrary within the technical level of the art at the time of this application. Therefore, the gist of the present invention should not be limitedly interpreted based on only the specific configuration of the present embodiment without showing a special reason.

FIG. 1 is a schematic view of an embodiment of the present invention, which corresponds to FIG. 10 in which a conventional device is described, and the members with the same reference numerals are the same members as those of the conventional device. In the figure,
11 is a W-axis base, 12 is a spindle head, and the head 12 is movable in the W arrow direction with respect to the W-axis base 11. 19, 4-way switch mounted on the W-axis base 11 LS ₁ ~LS _4,
Reference numeral 20 denotes a dog mounting plate having fixed dogs corresponding to the switches. The plate 20 moves relative to the switch group as the spindle head 12 moves in the direction of the arrow W, and the dogs are moved by the dogs. One or more of the switches LS _{1 to} LS ₄ are stepped on or released at the same time. As a result, ON / OFF signals of each limit switch are sent to the machine control device MTC, and the NC device controls the operation / stop of the W-axis feed motor M of the machine tool according to the contents of the signal.

In the switch group, the switch LS ₁ is for origin, the switch LS ₂ is for tool clamping and spindle head stroke control, the switch LS ₃ is for tool unclamp confirmation, and the switch LS ₄ is for Used for + and-overtravel detection. The above description is
Each switch L in the operation diagram of the switch group shown in FIG.
It also applies to S _{1 to} LS ₄ . FIG. 2 is an operation diagram of the above switch group, and in the drawing, concrete numerical values of the tool unclamping region and the normal stroke region length show an example. The vertical axis represents the W movement direction of the spindle head, and the horizontal axis represents the switch ON in the left direction and OFF in the right direction. The signal from each switch is displayed by the position of a point where a straight line (W-axis position) parallel to the horizontal axis intersects each operation line.

3 to 6 show the above-mentioned respective switches LS.
_It is a flowchart explaining the functions of _{1 to} LS ₄ , and these functions are incorporated as software in the machine control device MTC. However, since the function of the switch LS ₁ is only for confirming the origin, it is not included in the following description. Figure 3
FIG. 7 is a flowchart showing the sequence of automatic tool changing operation. Referring to FIGS. 1 and 2, when the W axis is moved to the tool unclamping position, the switch LS ₃ is turned on, the current tool is clamped by the collet unit, and the tool is returned. After mounting the new tool on the released collet part and moving the W-axis to the tool clamp position (W = 0), switch LS ₃ is turned off, switch LS ₂ is turned on, and the new tool is tightened on the collet part. It is fixed, and the tool change operation ends without error.

At this time, the switch LS ₃ remains off even though the W axis is moved to the tool unclamp position, or LS ₂ is turned off even though the W axis is moved to the tool clamp position. If it remains as it is, it is determined that some abnormality has occurred in the apparatus, and the operation is stopped. Here, the switch LS ₂ is assigned the function of confirming the clamp of the tool, and the switch LS ₃ is assigned the function of confirming the unclamp of the tool.

FIG. 4 is a flowchart showing a procedure for interlocking the W-axis so that the W-axis does not move to the tool unclamping area except during the automatic or manual tool changing operation. In other words, referring to FIG. 2, even if the W axis tries to move carelessly from the normal stroke area to the tool unclamping area, the switch LS ₂ is turned off and the W axis + direction interlock is applied. The axis feed stops. This procedure is always operating while the power of the machine tool is ON, and the one shown in the figure shows only one flow.

FIG. 5 shows that when the switch LS ₄ is activated,
That is, a flowchart for determining the direction when the W axis is manually returned to the normal stroke area or the tool unclamp area when an emergency stop is applied as a result of overtravel of the W axis is shown. If this determination is not made, an accident may occur in which the spindle head collides with the mechanical stopper by further manually feeding the W axis in the overtraveled direction.

Overtravel (switch LS ₄ is O
N) The procedure for manually returning the spindle head is to turn the W axis by turning the handle of the manual pulse generator while turning on the overtravel release button. At that time, switch LS
_{If 2} is ON, it means that overtravel has occurred in the-direction (see Fig. 2), so an interlock signal for the W-axis-direction is sent to the NC device so that manual feed can be performed only in the + direction. When the switch LS ₂ is OFF, it means that overtravel has occurred in the + direction, so an interlock signal in the + direction is sent out so that the W axis can be manually fed only in the-direction. This direction discriminating means
It is provided inside the machine control device MTC.

FIG. 6 shows a procedure for manually clamping a tool, in which the left main series is for unclamping the tool and the right sub-series is for clamping. Referring to FIG. 2, when the switch LS ₂ is ON, it means that the W axis is in the normal stroke region and the tool is in the clamped state, and the tool is about to be unclamped. That is, when the W-axis is jog (automatically) fed in the + direction, and as a result, the switch LS ₃ is turned on, the unclamp lamp is turned on and the W-axis feed is stopped to complete the unclamping of the tool.

The fact that the switch LS ₂ is OFF means that the W-axis is in the tool unclamping area and the tool is in the unclamping state, and the tool is about to be clamped. That is, the W axis is-
When the switch LS ₂ is turned on, the unclamp lamp turns off and the W-axis feed stops,
Tool clamping is complete. Regarding the origin detection function of the switch LS _1, the same usage as the conventional device is adopted.

[0025]

As described above, the device of the present invention corresponds to the dog position provided on the dog mounting plate, and LS ₂ is
(1) Check the tool clamp state, (2) Spindle head stroke limit during normal operation (stop the spindle head movement when the LS ₂ switch comes off the dog during normal operation), (3) Relief direction when overtravel is released Judgment, (4) To judge the clamp operation stop in the manual mode (press the operation button to switch to the jog mode, and continuously feed in the negative direction continuously until the LS ₂ switch is depressed, a series of operations are automatically performed) use,

LS ₃ is (1) Checking the tool unclamping state, (2) Stopping the unclamping operation in the manual mode (Press the operation button to switch to the jog mode, and manually feed in the + direction until you depress LS _3. By using the signal of one switch for up to four types of control functions, the number of switches used can be greatly reduced. We were able to achieve miniaturization around the W-axis and reduce wiring, and ensure highly reliable individual operation.

[Brief description of drawings]

FIG. 1 is a layout view showing a relationship between a limit switch group and dogs of the present invention.

FIG. 2 is an operation diagram of limit switches LS _{1 to} LS ₄ of FIG.

FIG. 3 is a flowchart showing a control operation of the machine control device MTC of FIG.

FIG. 4 is a flowchart showing another control operation of the machine control device MTC of FIG.

5 is a flowchart showing another control operation of the machine control device MTC of FIG.

FIG. 6 is a flowchart showing another control operation of the machine control device MTC of FIG.

FIG. 7 is a front view of a portal machine tool provided with the device of the present invention.

FIG. 8 is a side view of the machine.

FIG. 9 is an enlarged cross-sectional view in the vicinity of a spindle head of the machine.

FIG. 10 is a layout diagram showing a relationship between a limit switch group and dogs used in a conventional device.

[Explanation of symbols]

11 W-axis base 12 Spindle head 15 Spindle 19 Limit switch group 20 Dog mounting plate LS ₁ Limit switch for origin LS ₂ Clamp and stroke limit switch LS ₃ Unclamp confirmation limit switch LS ₄ + and-Overtravel detection limit Switch MTC Machine controller NC NC device.

Claims (1)

[Claims] 1. A collet part for supporting a main shaft in a main spindle head, a draw bar inserted through the main shaft, and a draw bar distal end provided with a collet part for gripping a tool, and the draw bar is always provided with a rearward biasing force. Tighten and clamp the tool,
A machine tool that moves the draw bar forward against the biasing force to release the collet to unclamp the tool is an X-axis, a Y-axis, a Z-axis, or one of the X, Y, and Z-axes. At least four linearly-moving feed shafts of a W-axis that can be aligned parallel to the shaft, and the main spindle head is driven and driven by the W-axis on a W-axis base parallel to the axis of the main shaft, The base is feed driven by at least one of the X-axis, Y-axis, and Z-axis, and is driven by a feed shaft that is parallel to the W-axis. An abutting portion for pressing the drawbar forward is provided, and the W axis can be moved to the tool unclamping area further rearward from the rear stroke end of the normal stroke area only in the unclamp mode, and the drawbar rear end and the W axis can be moved. The drawbar is moved forward against the biasing force by contacting the contact part of the base, and the collet part is released to unclamp the tool in the W-axis direction. In a position confirmation device for a moving spindle, at least three limit switches for detecting relative movement positions in the W-axis direction between the spindle head and the W-axis base and respective dogs corresponding thereto are provided, and the three limits are provided. The switch has an LS ₂ that detects a rear stroke end position in the normal stroke area of the W axis, and an LS ₃ that detects a tool unclamp position in the tool unclamp area.
The normal consists LS ₄ Metropolitan for detecting the rear overtravel detection position in front of the over-travel detection position and the tool unclamping region of the stroke area, when the limit switch LS ₄ detects the overtravel operated, the A spindle position confirming device comprising a direction discriminating means for receiving the detection signals of the limit switches LS ₂ and LS ₃ and driving the W axis only in a direction in which the W axis can be driven when the overtravel is released. .