JPS5947108A - Method and apparatus for controlling cutting in radial direction of rotary tool - Google Patents

Abstract

PURPOSE:To permit control of cutting in the radial direction of a rotary tool in an NC machine tool by installing an eccentric mechanism onto the tool and installing a speed reduction mechanism inside a tool holding tool. CONSTITUTION:The standard position for cutting in the radial direction of the share point of a tool 200 is the position of a cutting control shaft 24 in the case when installed into the top edge hole on the main spindle 2 of a tool holding tool 100. When the tool holding tool 100 is released, said tool holding tool is stored into a magazine by an automatic tool replacing apparatus, with a tool holding shaft 112 in eccentric state locked at a standard angle position. Since the tool is equipped with an eccentric mechanism, the main spindle simply has a normal structure, in comparison with the structure equipped with an eccentric mechanism built in the conventional main spindle, and thus easy work is permitted, and reduction of rigidity is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for controlling the radial depth of cut of a rotary tool in a numerically controlled machine tool such as a machine tool.

Conventionally, it'll be necessary to adjust the radial depth of cut of the tool tip using a numerically controlled machine tool such as a machining center.
When controlling lilJ, an eccentric mechanism is built into the main shaft,
This is done by moving the tool cutting edge in the radial direction via this eccentric mechanism, but according to this method, it is necessary to drill a large diameter eccentric inner hole in the main shaft over almost the entire length, making hIJ machining difficult. In addition to this problem, the rigidity of the main shaft decreases, and in order to maintain the rigidity, the outer diameter of the main shaft must be increased.In addition, it is not possible to increase the amount of eccentricity. I heard that there are also restrictions on the radial depth of cut of rotary tools.

The present invention provides a machine tool, in particular, a main ia that rotates with an exchangeable tool holder attached to the tip thereof, and provides relative movement between a rotary tool held by the tool holder and a workpiece. On the numerical side, such as a machining center that performs precise machining (D.1), in machine tools, the radial depth of cut of the rotary tool can be controlled without incorporating an eccentric mechanism in the main shaft, making machining easy and reducing the rigidity of the main shaft. A new depth-of-cut control method that enables control of a larger radial depth of cut than the conventional method with a built-in eccentric mechanism in the spindle, without requiring low F or particularly increasing the outer diameter of the spindle. and a device rt.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in more detail below based on m/-1 diagrams of the accompanying drawings showing embodiments thereof.

First, before going into the description of the embodiments, the principle of providing the tool holder with an eccentric mechanism according to the present invention (thereby controlling the radial cutting depth of the rotary tool) will be explained with reference to FIG.

Fig. 1 is a front view showing a tool holder that is replaceably fitted to the tip of the spindle. The eccentricity of the tool holding shaft 'I11 is the center, θ is the eccentricity, 200 is the tool holding shaft (this is the installed rotary tool, θ is the eccentricity II'll)
Rotation angle of l, Po +, t; position of the cutting edge of the tool 200 at the rotation reference angle position (0-0 position) of the four core axes,
P is the position of the cutting edge of the tool unit θ0 at the position where the rotation angle of the eccentric shaft is θ, and CP is the distance from the eccentricity 1■11 center C to the cutting edge position P (
(Determined by the cutting tool) SP: Distance from the center S of the mountain axis to the position P of the cutting edge (this is the radius of the cutting hole) Plane: Eccentricity Fy"ceC (Determined by the tool) θ: Rotation angle of the eccentric shaft, then The relational expression holds true.

-5p=i-100" -,2-CP -E30- c
Since os(/CP and SC are constant, -ribo motor (qθ)i, therefore, the eccentric tool holding shaft (l12)
By rotating and controlling θ, it becomes possible to control the cutting rotation radius γ=SP of the tool cutting edge corresponding to the hole in the workpiece to be cut between the minimum γmin and the maximum γmax. In this case, γmin is (+tII-centered tool holding shaft (l12) is at reference corner position iif PO1
Zunawaji is the minimum cutting rotation radius of the tool cutting edge P that occurs when θ=O, and γmax is the maximum cutting rotation radius that occurs when θ=l and θ01, and the difference between them is γmax−γm
in = λθ becomes the maximum cutting depth ml-. Therefore, the servo motor (11,0) and the eccentric tool holding 11'1l
If the reduction ratio with l(//2) is set appropriately, for example, /
The rotation angle of the tool holding axis per pulse can be controlled in steps of 0.001° from θ=θ° to 7g000, and therefore the depth of cut of the tool cutting edge P can be controlled from 0 to the maximum koe. I understand. In the above description, the symbols in parentheses are those shown in FIGS. 2 to 6.

Next, an embodiment of the device according to the invention, which is constructed to operate on this principle, will be described.

The device of the present invention shown in Figs.
0) The radial rotation control tool holder consists of three unit nodes, and the functions of each unit are as follows.

(A) Main spindle head cutting tool (This is the main shaft driver 1.9 that provides rotational cutting force, the main motor attached to the main Q4h head body, the gear gear that changes the speed of its rotation, and the radial fti control It consists of a main shaft for mounting and fixing a rotating tool.

(B) Synchronous rotation of the cut control float box main shaft and the cut control shaft; a differential float mechanism that superimposes the rotation of a servo motor on the synchronous rotation to produce relative rotation between both shafts; and radial control of the relative rotation. It consists of a connecting mechanism that connects the feed shaft number of the rotary tool.

(C) Deceleration of the relative rotation between the radial direction control rotary tool holder main shaft and the cutting ffi control shaft, and the eccentric machine 41? It consists of a mechanism that uses t to change the feed in the radial direction of the tool cutting edge, and a lock that automatically clamps and unclamps the tool holding shaft when attaching and detaching the tool holder to the main shaft. ing.

? '/Cl includes (1) a rotation transmission mechanism, (11) a connection mechanism, and (1) a combination of these units.
) Radial control rotary tool? lil control iso'+lJt kI will explain them separately.

(11 Structures of rotation transmission A) One shaft is rotatably supported on the main body of the spindle head A, and is attached to the rear end of the main shaft which is rotationally driven via a drive mechanism (not shown). The float 3 transmits the rotation of the main nib a to the gear O by using the gear S rotatably supported by the main body of the cutting control gear box B as an idle gear.The gear 6 transmits the rotation of the main nib a to the gear O. It is fixed to a shaft g which is rotatably supported, and transmits the rotation to the gear 9 in the differential gear box 7.Here, the main body of the cutting control gear box B is connected to the main shaft head A. The differential gear box 7 is fixed to the main body 1 of the cutting control gear box B, and the differential gear box 7 is supported in the main body 9 of the cutting control gear box B by means of bearings 10 and/or l. The gear 13ζ on Il'1lI1.2, which is rotatably supported by the differential gear box 7, is in mesh with the gear 13ζ. ][Bearing /6 and /71 in the n hole, so +14+
Supported axis/Fixed to If [attached to FiLI3
The rotation of the gear /9 is transmitted through the mark /g to the gear 19 fixed on the +RI+ /g outside of the differential gear box 7, and furthermore, the rotation of the float /9 is transmitted to the gear 19 fixed on the +RI+ /g of the differential gear box 7 through the mark /g. The gear 2- is used as an idle gear, with the gear 1 on the shaft 20 rotatably supported on the main body of the control gear box B.
can be conveyed to.

These two gears are drawbars that pass through the through hole of the main shaft.
Cutting control axis passing through hole 23, sliding key at 21I,
2, which is supported so that it can slide in the axial direction and transmit rotation through the left side, and which is controlled by the drawbar 23; 27. - It is rotatably supported by g and moss. Further, the gear unit is rotatably supported by a bearing 30 on the main body of the cutting control float box B, and also has keys 2H, 7D, ? / is supported so as to slide in the axial direction.

On the other hand, the depth of cut control a1++ r is connected by a key to the output shaft of the servo motor yo for controlling the depth of cut of the tool cutting edge, which is attached to the main body of the car box B, and the depth of cut control teeth &
Bearings are attached to the main body of box B/and 11. A gear I1.t is rotatably supported by a gear I1.t. ? The gear meshes with the gear fixed to the differential gear box 7, and the servo motor l
The rotation of Io causes the differential gear box 7 to rotate.

Here, float 3. /,,9. /3. /4t,/! , /9
The number of teeth of 2.2 and 2.2 shall be appropriately selected so that the rotational speed ratio between the rotational main axis λ and the cutting control axis 2 becomes /:/. That is, when the servo motor q0 does not rotate, the rotating main shaft and the cutting control shaft rotate synchronously, but when the servo motor q0 rotates, the rotation is caused by the gear d through the gear 3. The transmission is transmitted to the differential gear box 7, which constitutes a planetary float 1i'i 4'h in which the shaft 7.2 revolves around the gear 9. The rotation angle of the axis /,2, and the rotation angle of the gear wheel, /3. The rotation angle or superposition determined by /lI and /j, that is,
Upper 4i"(looked at, this M(folded rotation angle is tl'i
This output is transmitted to gear 1.2 through gears TE/9 and 2/.

In other words, INj between the rotating main shaft and the cutting control shaft
A 4-way differential shaft is installed in the 4-way differential shaft, and the rotation angle controlled by the feed servo motor tio is
Between 1I and the rotating main shaft -, the /F@ narrows down↓
The structure is such that the lighting rotation 1 of the lampshade ψ occurs.

(It) Connecting mechanism <VzKo) Drawbar, rotatably and freely movable in the axial direction in the through hole of 23: iit and cylinder S for tool clamping.
Pass through the moon hole on the left side of O's piston 111+
, 7, the cutting control shaft 2'l is
The piston of the drive cylinder 5da that moves this in the axial direction to engage and disengage, is advanced toward the tip of the main spindle by t4ta, and is attached to the radial control tool holder /θO (detailed explanation will be given later). Connecting shaft for tool cutting control provided in the through hole of the pull stud 10/ θ engagement portion 10 core a
The piston tea of the cylinder 5 for engaging and disengaging is connected to
By moving back the two shafts 24' and /θY, the connection between the two shafts 24' and /θY is made into several angles.

At this time, the forward and backward stroke ends of the piston t4za of the engagement/disengagement driving cylinder 5g are controlled by proximity switches S3 and S installed at the rear of the cylinder 51I, respectively.
The position of attachment and detachment is detected and confirmed by l-.

As seen, the cutting control shaft 2'IV when the tool is connected is positioned at a predetermined angular position by the servo motor <10, and the recess 241a of the connecting portion is used for mounting the radial control tool holder 100 onto the main shaft. The cedar S is released by the proximity switch 37 for detecting the maintenance of the connecting shaft 70.2 which is positioned at the time.

The clamping and unclamping of the slave direction control f111 tool holder 100 is performed by releasing the tightening of the radial direction control tool holder 100 when the left piston of the tool clamping cylinder SO is moved in the direction in which the force of the main shaft - is transferred to ibj+. and push it out,
On the other hand, piston! / is retracted in the direction opposite to the tip direction of the main shaft 2 to free the gear, the two gears, and the nut piece 26, the drawbar 23 causes the plate spring 5 to be pulled into the pull stud of the radial control tool holder 100 by the known tool tightening mechanism. 1
This is done by clamping and unclamping 0/.

(I) Radial control rotary tool control mechanism (¥2y)
A radial control tool holder 100 that is automatically attached to and detached from the tip of the spindle by a known automatic tool changer (not shown)
is the pull stud 10/concentric with the rotation center line S of the spindle.
through the through hole K1 of the tapered shank part 103.
It has a connecting shaft lθ which is rotatably supported by the ltll receiver IO'l and 103, and a gear 104 fixed to this shaft 102, and this gear 106 has a taper shank 10.3 and a tool holding shaft. It meshes with a gear 101 that is pivotally supported by the tool body 107, and this gear 10g is
One end is rotatably supported on the tool holder body/θ7 by a bearing lθ parallel to and eccentrically from the rotation center line S of the main body 107, and is also fixed to the tip of the tool holder body 107. Eccentric case forming part of the main body/Tool holding shaft rotatably supported by bearing iii on eccentric R passer of 10//Bearing on 2//
,? Eccentric cutting feed shaft whose other end is supported by //
The gears fixed to II are in mesh with each other, and furthermore,
This eccentric cutting feed shaft //'I is coupled to the reduction tooth four wheel unit/θθa input shaft //g by a key //A. This reduction gear unit) 100a is connected to a fixed part l/qf fastened to the taper shank part 703, and an output part fastened to the tool holding shaft/20 is connected to the rotational speed of the main shaft and eccentric cutting. The relative rotational speed difference with the rotational speed of the feed shaft //'l is reduced to a specified reduction ratio of 100& and output. This rotation is the output \ils
/20 is transmitted to the tool holding shaft //-1 which is fastened, and is further transmitted to the polling tool <-1-1 by tracing the eccentric bracket //. The rotational center line C of this boring bar/2 is offset by e from the rotational center line S of the main nId+2, so the cutting tool (boring tool) installed on the poling/(-/22), The cutting edge position P changes the radial distance from the center ssN of the spindle, that is, the cutting center, by rotating the eccentric tool holder @//2.As a result, the radial dimension of the cut hole can be controlled by the servo This is possible by controlling the rotation of the motor.

The angle position was determined in advance by the detection of (
Spindle orientation) Taper shank of tool holder 100 to tip engaging part of spindle f Kaki-/30
7,? The keyway in the grip of /? / is entered during automatic tool change (Fig. 1). At this time, connecting shaft 1
0λ lock bottle/3 tips/? Ua as main axis-
key/tip of 30*; (by pressing it against the surface,
Gene/, slide down against 3J, as a result, bottle/,? , the grooved cam bin 73 attached to the tip of 2.
The lock bin 73S slides and jumps into the tooth groove at the predetermined position tt-'' of the float IOA. 9 (1, IMl). When the tool holder 100 is detached from the spindle, the tool holder 100 is removed from the tip of the spindle.
moves forward, the slide bin/32 becomes free, and the grooved cam bin/J'! is moved by the spring/, 7.3. is pushed out, and the lock bin i3s jumps into both fronts of the predetermined position 1i of the wheel lθ6 by the cam 6j, and becomes a coin lock state.

Next, the operation and conditions at the time of mounting the tool holder lθO will be explained.

/ When a tool change command is issued, the spindle - detects the detector 30.
It is indexed to a fixed position by the detection signal of / and 3θ (the tip key/30 force S is indexed to a fixed position iPt by 1θ).

Yu servo motor I! Depth of cut control axis by 0, 24t
is positioned at a reference angular position 020 (a position corresponding to the reference angular position i?t of the tool holder 100 in which the recessed portion μa of the cutting control shaft 2da is positioned at a fixed position).

3. The cutting control shaft 2 is an engagement/disengagement drive/unlinter.

is retreating.

Hiroshi Draw Perco 3 is in the unclamped state (the piston St of the tool clamp cylinder SO is in the 2nd and 2nd +
(located in forward position on the far left).

is locked in.

Based on the above conditions of /-j, the tool holder /θO is automatically positioned by an automatic tool changer (not shown) so that the groove /J/ of the tool holder /θO enters the tip key /30 of the main spindle. and installed. After that, the drawbar,
23 is in a clamped state due to the retreat of the piston 5 to the right end and the elasticity of the spring jg, clamping the tool, and the cutting control shaft is maintained by moving the piston 5 of the cylinder 3 to the left. The locking concave and convex portions J4'a and 702& are engaged, and the cutting control shaft 2da and the connecting shaft IO-
is connected to. Also, connected shouts (10 lock bins/
3 is pressed against the tip of the main spindle, and the tool holder io
The 4A lock on the connecting shaft 102 of o is released.

Is it radial? 1ill'+Ml and sending are performed as follows.

When the tool holder 100 is attached to the tip hole of the main spindle, the cutting control shaft 2a, the 2nd place 1 mark becomes the reference position for the radial cutting of the cutting edge of the tool -〇〇.

In addition, when the tool holder is detached, the operation proceeds in the reverse order of / to the left above, and the detached tool holder 10θ is (14
With the centered tool holding shaft //, 2 locked at the reference angular position (θ=θ), the tool is stored in the magazine by the automatic tool changer.

If the orientation of the spindle is still IH, stop the control motor electrically. By the way, magnetic sensor? Is O/ a notch system? I￥1] It is fixed to the main body of gear box B.

Since the method of the present invention is carried out as described above, and the apparatus of the present invention has the configuration and operation as described above,
It is clear that the present invention has the following effects.

/ Eccentricity (Since the tool is equipped with an eccentric mechanism, there is no possibility that the main shaft will drop.) There is a reduction mechanism inside the tool holder and its reduction ratio is large, so the effects of backlash of the differential gear mechanism etc. Since the differential gear mechanism uses spur gears, it can withstand high-speed rotation and has less backlash than normal gears that use bevel gears. mosquito.

]＼j('1411/) 1 can be made large. The amount of control can be made large. (This is related to the reason in item 7 above. /As an example, the 10) S. A large reduction ratio on the tool holder side (for example, 1)
:/) It has a speed reduction mechanism, and the power of the control system (servo motor, differential gear mechanism, control shaft, etc.) is small, so the mechanism can be simplified, so it is inexpensive. This includes things that can be done and done.

[Brief explanation of the drawing]

Fig. 1 is an axial cross-sectional view showing the 4.74 configuration of the spindle head of a machining center equipped with a holder for controlling the radial depth of cut according to the present invention, and Fig. 3 is a front view seen from the right side of Fig. 2. , FIG. 4 is a front view of the tool holder in the Wja diagram as seen from the left side, FIG. 5 is a partial sectional view illustrating the locking mechanism of the tool holder, and FIG. FIG. /...Spindle head of machining center; K...Spindle, G...
Cutting control gear box body; 7...Differential gear box; lθO...
Tool holder, 100a...reduction gear mechanism. Patent Applicant: Ikegai Iron Works Co., Ltd. Agent: Teru Sogado

Claims (1)

[Claims] / In a numerically controlled machine tool that is equipped with a rotating spindle with a tool holder attached to its tip so that it can be replaced, and that performs machining by relative movement between the rotating tool and the workpiece, When the tool holder is released, the tool holder is rotated to a predetermined position. At the same time as the tip of the spindle stopped at the angular position is fitted, the lock of the eccentric mechanism is released, and the tool holder is tightened slightly in the spindle through-hole. A cutting control shaft, which rotates synchronously with the main shaft through a differential mechanism whose rotation is controlled by a servo motor and is movable in the axial direction in the through hole of the tightening mechanism, is connected to the eccentric mechanism at a reference angular position of the tool holder. The position of the cutting edge in the radial direction of the tool held in the tool holder is controlled by the servo motor through the cutting control shaft and the eccentric mechanism when the main spindle is stopped by numerically controlling the rotation angle from the reference angular position. A method for controlling the radial cutting depth of a rotary tool, which is characterized in that it can be controlled regardless of whether the tool is being machined.It is equipped with a main shaft that rotates with an exchangeable tool holder attached to the tip, and the rotary tool and the workpiece are In a numerically controlled machine tool that performs machining by moving relative to the tool holder, there is a tool holder shaft that is rotatably supported eccentrically on the tool holder body and holds a tool at its tip, and a tool holder that is rotatably supported concentrically with the tool holder body. an eccentric mechanism consisting of a connecting shaft that is pivotally supported and has an engaging portion formed at its rear end, and a speed reduction mechanism that connects the two shafts; A tool holder equipped with a locking mechanism Q, and a large circle arranged through the main shaft JJ, which holds the rear end of the tool holder when fitted and springs backward to tighten it, and when changing the tool, presses it forward. 74. a tightening mechanism for a tool holder including a hollow drawbar for releasing the tool holder; a cutting control shaft formed with a retaining portion that engages and disengages from the connecting shaft of the tool holder;
A gear drive mechanism rotates this cutting control shaft in synchronization with the main shaft, and a differential tooth (
This is the difference between 2 bottles! a servo motor that superimposes a desired rotation on the cutting control shaft via a gear mechanism, and a position detection mechanism that stops the main shaft and the cutting control shaft at a predetermined reference angle position prior to tool exchange; + appetizers (+i
*The rotation control mechanism and the cut 1 lilJ ji'
A drive device for advancing and retracting the cutting control shaft in the axial direction to engage and disengage the l-axis and the connecting shaft of the tool holder, and a position detection device for confirming the forward and backward positions of the cutting control shaft. The radial cutting edge position of the tool held in the tool holder can be controlled regardless of whether the spindle is stopped or during machining! Pfg, a radial cutting control device for a rotary tool. A tool holder that is replaceably attached to the base has a shank with a protruding pull stud that is removably inserted into the hole at the end of the spindle, and a tool holder that is concentrically located within this shank. a connecting shaft that is rotatably supported and has a retaining portion near the rear end of a through hole provided in the pull stud; a holder body integrally formed at the tip of the shank; a tool holding shaft that is rotatably supported on the first jaw holder body parallel to and eccentrically and having a removably attached boring tool protruding from its tip; and a reduction gear that connects this tool holding shaft and the connecting shaft. a gear mechanism; and a pin that is movably disposed near the tip of the shank, engages with the reduction gear mechanism 14, and is moved by contact with the end face of the main shaft during tool exchange. The boring tool is equipped with a locking mechanism that releases the engagement with the tool holder, and the boring tool that is locked at the reference angle position of the tool holder is unlocked using the tool exchange fitting operation. A patented tool holder that can control the radial cutting edge position by numerically controlling the rotation angle of the eccentric tool holding shaft via the connecting shaft engaged by the cutting control spider and the retaining part in the main J+ through hole. 1. A radial cutting control device for a rotary tool as set forth in item 4.