JPH11239941A - Tool changing arm for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time for replacing a tool. SOLUTION: A tool changing arm 100 for a machine tool has an arm member having a tool clamp part 11 rotated forward/backward driven by a rotary shaft 14 to be opened in a rotational direction at every end, a retaining lever 2 journalled to the arm member to open/close the tool clamp part 11, a spring device 3 pressing energizing the retaining lever 2 in a direction tightening the tool clamp part 1, and a cam member 4 turning the retaining lever 2. Since the retaining lever 2 is not housed in the arm member, it can be formed short and a moment arm is shortened, to lighten the inertia force of a tool T. By reducing inertia moment of the arm member clamping the tool T, the tool changing arm 100 can be rapidly turned, a time for changing the tool is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a machine tool having a tool spindle for driving a rotary tool, and more particularly, to an automatic tool changing apparatus for automatically changing a rotary tool of a machine tool. Belongs to.

[0002]

2. Description of the Related Art As a prior art of an automatic tool changer for automatically changing a rotary tool of a machine tool, Japanese Utility Model Publication No.
There is a tool changing arm of a machine tool disclosed in Japanese Patent No. 2144. The tool change arm of this machine tool is mainly driven by an arm member having a pair of tool gripping portions formed at both ends, which are rotatably driven and forward and backward driven while being pivotally supported by the rotating shaft and opened in the same rotation direction. It is configured. A holding lever for opening and closing the tool grip is pivotally attached to the arm member near the root of the tool grip so as to be pivotable. The arm member incorporates a spring device that presses and biases the holding lever in the closing direction, and a lock device that fixes the holding lever at a closed position where the tool is gripped.

When the tool change arm of the machine tool grips the tool with the tool gripping portion, a flange (collar) portion of the tool comes into contact with an inclined surface formed on the holding lever, and the holding lever is pushed open to open the holding lever. The part is held on the tool grip by the holding lever.

[0004]

However, in the above-described tool changing arm of a machine tool according to the prior art, since the spring device and the lock device are built in the arm member, it is difficult to shorten the arm member. Weight reduction was also difficult. Therefore, since the moment arm and the mass of the arm member are increased, the moment of inertia is increased, and a large torque is required for turning the arm member at high speed.

In addition, since the tool is gripped near the tip of the long arm member, when the arm member is turned at a high speed, both the circumferential acceleration due to the angular acceleration and the radial acceleration due to the centrifugal acceleration are increased, and the arm member is increased. An excessive force may be applied to the tool gripping portion and the flange portion (gripped portion) of the tool. As a result, the turning angular velocity and angular acceleration of the arm member must be kept low, so that it takes time to turn the arm member, which hinders a reduction in tool replacement time.

In addition, when the arm member grips the tool with the tool gripping portion, the tool is applied to the holding lever against the pressing force of the spring device that constantly biases the holding lever in a direction to pinch the tool. Abutted portions to be gripped. Then, the slope of the holding lever comes into contact with the flange of the tool and slides, and the holding lever is pryed open by the pressing force generated along with the frictional force, and the flange of the tool is gripped by the tool gripping part of the arm member. I have. Therefore, when gripping the tool with the tool gripping portion of the arm member, slowly rotate the arm member so that the excessive force is not applied to the holding lever and the flange portion of the tool, and the flange portion of the tool is held in the tool gripping portion. Had to be sandwiched. This also hindered reduction in tool change time.

Therefore, an object of the present invention is to provide a tool changing arm of a machine tool capable of shortening the tool changing time as compared with the above-mentioned conventional technology.

[0008]

Means for Solving the Problems and Their Functions / Effects To solve the above problems, the inventor has invented the following means. (First Means) A first means of the present invention is a tool changing arm of a machine tool according to the first aspect. In this means, since the holding member is not provided in the arm member having the tool gripping portion at the tip end but is externally attached, the length of the arm member can be shortened and its mass can be reduced. Further, since the length and mass of the arm member are small, not only the moment of inertia of the arm member is small, but also the holding lever and the spring device are located near the rotation axis of the arm member, and the tool changing arm including the holding lever and the spring device is provided. Has a small moment of inertia. Furthermore, since the arm member is short, even when the tool is gripped by the tool grip portion at the tip thereof, since the moment of inertia of the tool and the tool changing arm is small, acceleration and deceleration of the angular velocity of the arm member can be performed at higher speed. . In addition, the acceleration applied to the gripped tool is reduced because the arm member is short, and without applying excessive inertial force to the tool gripping portion of the arm member and the gripped portion of the tool,
The arm member can be turned in a short time.

In addition, when the tool gripping portion of the arm member grips the tool, the holding lever is appropriately rotated by the cam member to receive the gripped portion of the tool in the tool gripping portion. Thereafter, the rotation of the pressing lever by the cam member is released, and the pressing lever presses the gripped portion of the tool into the tool gripping portion by the action of the spring device. therefore,
Since unnecessary frictional force or pressing force does not act between the holding lever and the gripped portion of the tool as in the related art, gripping of the tool by the tool gripping portion is performed smoothly and in a short time. Become like Also, when the tool to be replaced is separated from the tool gripping portion, the holding lever opens the tool gripping portion of the arm member by the action of the cam member without applying unnecessary frictional force or pressing force, so that the tool is released. The operation can be performed smoothly and in a short time.

Therefore, according to this means, there is an effect that the tool change time can be shortened as compared with the above-mentioned conventional technique. (Second Means) A second means of the present invention is a tool changing arm of a machine tool according to the second aspect. In this means, the arm member has a pair of tool gripping portions at both ends which are symmetrical twice and open in the same rotation direction at both ends, and the holding lever and the spring device are equipped with one pair and two pairs. Therefore, while one tool gripper is attaching / detaching a tool to / from the main spindle, the other tool gripper can exchange a tool at the tool exchange position, which is reasonable. . That is, when one tool gripper removes the tool from the spindle and turns to reach the tool change position, the other tool gripper grips the next tool from the tool change position and reaches the position of the spindle, so that the arm member It is possible to change the tool of the main spindle only by rotating the shaft about half a turn.

Therefore, according to this means, in addition to the effect of the above-mentioned first means, there is an effect that the tool change time can be further reduced. (Third Means) A third means of the present invention is a tool changing arm of a machine tool according to the third aspect. In this means, when the arm member advances away from the main shaft as viewed from the main shaft of the machine tool, the lock device locks both holding levers at positions where the tool grips at both ends of the arm member are closed. Therefore, in a state in which the arm member is advanced away from the main shaft, the both holding levers are locked at the positions where the tool holding portions at both ends of the arm member are closed, and there is no possibility that the tool comes off from the tool holding portion. Can be turned quickly.

Conversely, according to the present invention, both holding levers are unlocked by the lock device when the arm member is retracted toward the main shaft. In a state where the arm member is retracted toward the main shaft, the both holding levers are unlocked, so that the tool can be removed from the tool gripping portion without applying excessive force. In other words, the tool can be separated from the tool gripping part while the tool is pushed into the spindle, and no excessive force is applied at that time.

Therefore, according to this means, in addition to the effect of the above-mentioned first means, there is an effect that the tool changing time can be further reduced. (Fourth Means) A fourth means of the present invention is a tool changing arm of a machine tool according to the fourth aspect. In this means, the holding lever is disposed so as to intersect with a line connecting the tool grip portion and the rotation center of the arm member, is pivotally supported by a pivot portion provided on the arm member, and is rotatably supported. It is opened and closed by a cam member arranged on the outer periphery of the. Therefore, even if the position of the pivot portion for pivotally supporting the holding lever is arranged close to the rotation center of the tool changing arm, the protrusion of the cam member for opening and closing the holding lever can be formed large, so that the tool By changing the length of the exchange arm, its turning radius can be reduced.

Therefore, according to this means, in addition to the effects of the first to third means described above, there is an effect that the turning speed of the tool changing arm can be further increased.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the tool changing arm of the machine tool according to the present invention will be clearly and fully described in the following embodiments so that those skilled in the art can understand the present invention. Embodiment 1 (Schematic Configuration of Embodiment 1) As shown in FIGS. 1 to 3, a tool changing arm 100 of a machine tool according to Embodiment 1 of the present invention holds a tool T and rotationally drives a spindle S. (See Fig. 1)
This is an apparatus for automatically exchanging the tool T between the tool T and a tool exchange position P (see FIG. 3) where the tool T is temporarily placed.
The tool changing arm 100 according to the present embodiment includes, as main components, an arm member 1, a holding lever 2, and a spring device 3.
, Cam member 4 and lock head 1 as a lock device
7a.

As shown in FIG. 1, the arm member 1 is supported by a rotary shaft 14 via a slide pin 15 and a shaft member 16, and is driven to rotate and forward and backward by the rotary shaft 14. . As shown in FIGS. 2 and 3, the arm member 1 has a two-fold rotationally symmetrical shape that becomes the same shape when it is rotated by 180 ° about its rotation axis 14 (see FIG. 1). At both ends. The arm member 1 is one, but the holding lever 2
The spring device 3 is provided with one pair and two pairs.

Each of the holding levers 2 is rotatably supported at a middle portion of the arm member 1 via a pivot portion 20, and a holding roller as a tip end for opening and closing the tool holding portions 11 at both ends of the arm member 1. It has 21. Each spring device 3
Are held in the arm member 1, each of which abuts against the holding lever 2 at the tip 31, and presses and presses the holding lever 2 in a direction to close the tool gripping portion 11. Cam member 4
Are fixed to an outer cylindrical member 18 supporting the arm member 1 coaxially with the rotation shaft 14 of the arm member 1.
The pressing lever 2 is rotated by the two projecting portions 41 and 43 in contact with the cam roller 22 as the rear end portion, and the tool gripping portion 11 is opened.

As shown in FIG. 1, a concave portion 10 forming a low cylindrical space is provided on the front surface (the surface facing away from the main shaft) of the central portion of the arm member 1, and the holding lever 2 is provided with a tool holding portion 11 Is opened, the rear end of the spring device 3 projects into the recess 10. However, when the lock head 17a disposed coaxially with the rotation shaft 14 retreats in the main axis direction, the lock head 17a
The rear end of the spring device 3 cannot project into the recess 10 when the lock head 17a is fitted. That is, the lock head 17a
The lock device locks the holding lever 2 in a state in which the tool gripping portion 11 is closed by preventing the spring device 3 from retracting by fitting into the concave portion 10 of the arm member 1.

Therefore, when viewed from the main shaft S, the arm member 1
Is moved away from the spindle S, the lock head 1
7a is fitted in the concave portion 10, and the both holding levers 2 are locked at positions where the tool gripping portions 11 at both ends of the arm member 1 are closed. On the other hand, when the arm member 1 is retracted toward the main shaft S, the lock head 17 is moved from the concave portion 10 of the arm member 1.
a is released, the spring device 3 can be retracted, the two holding levers 2 are unlocked, and the tool gripper 11 can be opened.

(Detailed Configuration of First Embodiment) The configuration of the tool changing arm 100 of the machine tool according to the present embodiment has been outlined above. Next, the configuration of the tool changing arm 100 will be described in more detail. As shown in FIG. 1, a tool change arm base 5 fixed to the same base (not shown) as the main spindle S is rotated by a built-in driving device (not shown) and is driven to rotate forward and backward. 14 is supported in a state of protruding parallel to the main axis S. As shown in FIG. 3, the rotation shaft 14 is located directly above the tool change position P and at an angle of 52 degrees from directly above the main spindle center A.
The circle locus drawn by the center of the axis is the spindle center A and the tool change position P
It is arranged at a position passing through.

As shown in FIG. 1 again, a substantially hollow cylindrical outer cylinder member 51 is fixed to the tool exchange arm base 5 coaxially with the rotating shaft 14. A cylindrical internal space 50 is formed. In the internal space 50 of the outer cylinder member 51, the slide pin 15, a part of the shaft member 16, the slide ring member 18, and the plurality of fixing bolts 19 are provided.
Etc. are accommodated. A ring-shaped cam member 4 is fixed to the distal end of the outer cylinder member 51 with a plurality of bolts.

At the distal end of the rotary shaft 14, the base end of a substantially hollow cylindrical shaft member 16 is firmly fixed with a plurality of fixing bolts 19 coaxially with the rotary shaft 14. The center part of the arm member 1 is fixed to the part coaxially with the shaft member 16 with eight bolts. Therefore, the arm member 1
Is not only arranged coaxially with the rotating shaft 14,
Since it is fixed to the rotating shaft 14 via the shaft member 16,
Rotational drive and forward / backward drive are performed in accordance with the rotational movement and forward / backward movement of the rotating shaft 14.

A substantially hollow cylindrical sliding ring member 18 is provided between the outer peripheral surface of the shaft member 16 capable of rotating and moving forward and backward and the inner peripheral surface of the fixed outer cylindrical member 51. It is inserted and reinforces the rigidity of the shaft member 16. The outer diameter of the sliding ring member 18 is set so as to generate an appropriate frictional force between the sliding ring member 18 and the inner peripheral surface of the outer cylindrical member 51, and only a small frictional force is generated between the sliding ring member 18 and the outer peripheral surface of the shaft member 16. The inner diameter is set so that it does not occur.

A ring-shaped regulating member 51a projecting inward from the inner peripheral surface of the outer cylinder member 51 is fixed to the distal end surface of the outer cylinder member 51. The restricting member 51a is provided for the purpose of restricting a later-described sliding ring member 18 from retreating too far in the main shaft direction. The sliding ring member 18 has a pair of through holes into which both ends of the slide pin 15 disposed through the shaft member 16 are fitted. On the other hand, the shaft member 16 is formed with an oval through hole 16a that is long in the axial direction of the shaft member 16 in a direction orthogonal to the axial direction. In the through hole 16a, a cylindrical slide pin 15 is provided. The shaft member 16 is fitted so as to be movable back and forth within a predetermined range. The shaft member 16 further includes a rotating shaft 14.
A through hole 16b is formed coaxially with the through hole 16b.
A lock shaft 17 whose front end is a lock head 17a whose diameter is larger than the inner diameter of the through-hole 16b is fitted into b so as to be slidable in the front-rear direction. Then, the lock shaft 17 having this lock head 17a at the tip is
5 penetrates, and the member is fixed to the slide pin 15. A spring 25 is provided on the outer periphery of the lock shaft 17. One end of the spring 25 is in contact with the lock head 17a, and the other end of the spring 25 is in contact with a snap ring fixed to the inner periphery of the outer cylinder member 51, so that movement is regulated.

Therefore, the rotation shaft 14 moves in the axial direction from the state where the arm member 1 shown in FIG.
When the arm member 1 moves away from the main shaft S by moving the shaft member 16 in conjunction with the movement of the rotating shaft 14,
Since the slide ring member 18 is left behind by the movement of the shaft member 16, the lock head 17 a as a lock device fits into the recess 10 of the arm member 1 via the slide pin 15. As a result, the rear end of the spring device 3 is
And both holding levers 2 are locked at positions where the tool gripping portions 11 at both ends of the arm member 1 are closed. Therefore, in a state in which the arm member 1 has advanced away from the main shaft S, the tool holding portions 1 at both ends of the arm member 1
Both holding levers are locked at the position where 1 is closed,
Since there is no possibility that the tool T comes off from the tool holding portion 11, the arm member 1 can be quickly turned.

Conversely, as shown in FIG. 1 again, when the arm member 1 is retracted toward the main shaft S when viewed from the main shaft S,
The retraction is restricted by the restriction member 51a, and the sliding ring member 18 is
Is left behind, so that a lock head 17a as a lock device is
From the concave portion 10 of FIG. Then, as shown in FIG. 3 again, the rear end of each spring device 3 can protrude into the space of the concave portion 10, and each holding lever 2 urged by each spring device 3 is unlocked. . Therefore, when the arm member 1 is retracted toward the main shaft S, both the pressing levers 2 are unlocked, so that the tool T can be removed from the tool gripping portion 11 without applying excessive force.

In other words, the tool T can be separated from the tool holding portion 11 while the tool is pushed into the spindle S, and no excessive force is applied at that time. Further, the tool T to be held by the tool holding portion 11 at the opposite tool holding portion 11 located at the tool changing position P without applying excessive force.
Can be replaced by a tool intermediate transfer device (not shown).

As shown in FIGS. 2 and 3 again, the arm member 1 has a tool holding portion 11 opened at both ends in the same rotation direction, and at two places on the inner periphery of the tool holding portion 11, A ridge 12 is formed. In addition, each tool gripper 1
On the opposite side of the opening 1, one adjusting screw 13 is screwed into a position and direction passing through the center line of the tool T where the axis of the screw is in the same direction as the circumferential direction and the extension of the screw is gripped. The grip depth of the tool T can be adjusted appropriately.

Each holding lever 2 is, as shown in FIG.
It is a member having a three-stage staircase shape, and is rotatably supported by a pivot portion 20 at an intermediate portion of the arm member 1 at an intermediate portion thereof. At one end of each holding lever 2, a holding roller 21 for holding the tool T is rotatably supported by the tool holding portion 11 of the arm member 1. ) Is formed at the tip end of the holding lever 2 which comes into contact with the holding lever 2). Press roller 21
A ring-shaped ridge 22 is formed over the entire outer peripheral surface of the tool T. The pressing roller 21 has a ridge 22 to contact the outer peripheral portion of the flange portion of the tool T and grip the tool T with the tool grip portion 11. have. Therefore, when the tool T is tightened or loosened by the holding lever 2 on the tool gripper 11 of the arm member 1, the holding roller 21 is provided between the holding roller 21 at the tip of the holding lever 2 and the flange of the tool T. Rolls, so little friction occurs. As a result, not only the tip of the holding lever 2 but also the flange of the tool T is prevented from being worn.

Conversely, at the other end of each holding lever 2, a cam roller 23 that rotates smoothly by contacting the outer peripheral surface (cam surface) of the cam member 4 is rotatably supported. And a rear end portion of the holding lever 2 which comes into contact with the cam member 4. Therefore, the rolling frictional force between the rear end of the holding lever 2 and the cam member 4 is small, and the rear end of the holding lever 2 smoothly rolls along the outer peripheral surface of the cam member 4. Further, for the same reason, wear of the rear end of the holding lever 2 is also suppressed.

Here, the rotation axis of the pivot portion of the holding lever 2, the rotation axis of the holding roller 21, and the rotation axis of the cam roller 23 are not only parallel to each other, but also
It is also parallel to the rotation axis 14 of the arm member 1. As shown in FIG. 2, the pivot portion 20 that supports the holding lever 2 is provided at a position slightly offset in the rotation direction from a center line L connecting the tip of the arm member 1 and the center of rotation. The lever 2 is disposed so as to intersect a center line L connecting the tip of the arm member 1 and the rotation center C at an angle of approximately 60 °. The projecting portions 41 and 43 of the cam member 4 for opening the holding lever 2 with respect to the tool gripping portion 11 are provided at an angular position of 52 °.
(And 232 °), the arm member 1 is located at a position opposite to the rotation direction, that is, slightly behind the cam roller 23 of the holding lever 2. This allows
The holding lever 2 is formed by the projections 41 and 43 of the cam member 4.
Pivots about the pivot portion 20 and opens the tool holding portion 11 at a distance from the tool holding portion 11. Therefore, even when the radius of the arm member 1 is shortened and the mounting position of the holding lever 2 is brought closer to the rotation center C of the arm member 1, it is sufficient to adjust the amount of protrusion of the projecting portions 41 and 43 of the cam member 4. Since the opening angle of 2 can be secured, the turning radius of the arm member 1 can be further reduced.

As shown in FIG. 3 again, each holding lever 2
Has a pressed surface where the tip end surface 31 of the spring device 3 is in contact with an intermediate portion between the pivot portion 20 and the pressing roller 21, and is always urged by the spring device 3 in a direction to close the tool gripping portion 11. Conversely, the cam roller 23 forming the rear end of each holding lever 2 comes into contact with the protruding portions 41 and 43 and the flat portions 42 and 44 formed on the outer periphery of the cam member 4 and rolls. When the cam roller 23 of the cam member 4 rides on the protrusions 41 and 43 of the cam member 4, the cam member 4 pushes the cam roller 23 of the holding lever 2 outward against the urging force of the spring device 3, and the holding lever Is rotated. That is, the cam roller 2 of the holding lever 2
3 moves on the protrusions 41 and 43 of the cam member 4, the holding lever 2 rotates and the tool holding portion 11 of the arm member 1 rotates.
Is opened. Note that the shape of the cam member 4 fixed to the outer cylinder member 51 coaxially with the rotation shaft 14 has a two-fold rotationally symmetric shape that becomes the same as the original shape when rotated by 180 °.

As shown in FIG. 3, the pair of spring devices 3 are built in the arm member 1 and arranged on the same axis orthogonal to the axis of the rotating shaft 14. The distal end surfaces 31 of the spring devices 3 are disposed to face each other, and come into contact with a pressed surface formed at an intermediate portion between the pivot portion of each press lever 2 and the press roller 21 to be pressed. The surface is urged. The rear end surfaces 32 of the spring devices 3 are opposed to each other with the concave portion 10 at the center of the arm member 1 interposed therebetween, and project into the concave portion 10 when each holding lever 2 is at the open position.

When the holding lever 2 is in the open position (loose position) and the rear end of each holding lever 2 projects into the recess 10, the lock head 17a is fitted into the recess 10 and Lever 2 cannot be locked. However, as described in the following operation, when the holding lever 2 is in the open position and the rear end of each holding lever 2 projects into the recess 10, the lock head 17a enters the recess 10. An operation sequence is defined so as not to occur.

As shown in FIG. 5, each spring device 3 includes a push rod 30 having a front end surface 31 formed of a curved surface and a rear end surface 32 formed of a flat surface.
And a coil spring 33 which presses and biases the coil in the distal direction. Therefore, what is referred to as the front end surface 31 and the rear end surface 32 of the spring device 3 in the above description is the front end surface 31 and the rear end surface 32 of the push rod 30.

(Operation and Effect of First Embodiment) Since the tool change arm 100 of the machine tool of this embodiment is configured as described above, it operates and operates as follows. That is, as shown in FIGS. 6 and 7, the sequence for exchanging the tool T held on the spindle S with a new tool T is performed by the rotation of the rotary shaft 14 and the tool exchange arm of the present embodiment driven by the forward and backward movement. This is done by the action of 100.

First, from the initial state (see FIG. 2) where the tool gripper 11 of the arm member 1 is at the standby position at the angular position of 0 ° and holds nothing, and the holding lever 2 is also at the open position (see FIG. 2). The exchange sequence starts. In this initial state, the arm member 1 is at the retracted position when viewed from the main shaft S, and the rotation surface of the tool gripper 11 of the arm member 1 is located on the same plane as the flange portion of the tool T held on the main shaft S. I have.

From this standby position in the initial state, the arm member 1 is moved 5 degrees in the forward direction (the direction in which the tool gripper 11 is open).
After rotating by 2 ° (FIG. 7), the center of the tool gripper 11 of the arm member 1 coincides with the center A of the main shaft S, and the tool gripper 11 grips the flange of the tool T. At this time, the rear end of the holding lever 2 is rolling on the gentle slope of the projection 41 of the cam member 4, and as the flange portion of the tool T enters the tool holding portion 11 of the arm member 1, The leading end presses the flange of the tool T to close the tool gripper 11. In this state, the holding lever 2 holds the tool T on the tool holding portion 11 by the urging force of the spring device 3.

The tool gripper 11 on the opposite side at the angular position 232 ° is a new (used in the next step) transported to the tool changing position P by a tool intermediate transport device (not shown).
Hold the tool T. Next, as shown in the lower part of FIG. 6, the tool change arm 100 moves forward as viewed from the main shaft S, and removes the tool T straight from the main shaft S while maintaining the angular position of 52 ° without rotating. (See FIG. 1). Then, as shown in FIGS. 1, 3, and 6, the lock head 17a
Is fitted in the concave portion 10 of the arm member 1 and the retraction of the spring device 3 is prevented, so that the holding lever 2 is locked at a position where the tool T is still tightened on the tool gripping portion 11 of the arm member 1. Further, since the tool changing arm 100 including the holding lever 2 is retracted, the rear end of the holding lever 2 is disengaged from the cam member 4, and the holding lever 2 is not opened by the protrusions 41 and 43 of the cam member 4.

Thus, the operation of the tool T
The arm member 1 rapidly turns to an angle position of 232 ° while the arm member 1 is firmly gripped by the tool gripper 11 (FIG. 7).
of). Even if this turning movement is very rapid, the tool T is firmly held by the tool holding portion 11 by the lock device, and therefore, the tool T
Is effectively prevented from dropping out of the tool holding portion 11.

At this time, as shown in the upper part of FIG.
In the process in which the angular position rapidly moves from to 232 °, it looks as if the rear end 23 of the lever 2 passes the protrusion 43 of the cam member 4 (see FIG. 2). However, since the tool changing arm 100 including the holding lever 2 is retracted, the rear end 23 of the holding lever 2 is disengaged from the cam member 4 in the axial direction of the rotating shaft 14, and the protrusion of the cam member 4 4
It only slips by the side of 3 and the holding lever 2 does not open.

When the tool T extracted from the main shaft S is at the 232 ° angle position as described above, the tool T gripped by the tool gripper 11 on the opposite side of the arm member 1 is 52 °.
, And is located in front of the main shaft center A.
When the arm member 1 is retracted toward the main shaft S while maintaining the rotation angle as shown in the lower part of FIG. 6, the tool T gripped by the tool gripper 11 is fitted straight into the main shaft S. It is. At this time, the lock head 17a is disengaged from the concave portion 10 of the arm member 1 during the retreat, and the lock that fixes the holding lever 2 to the tightened position is released, but the holding lever 2 is urged by the spring device 3 and In addition, it continues to stay at the tightening position.

As a result, the tool T is inserted into the main shaft S to a sufficient depth as the arm member 1 further retreats without coming off from the tool holding portion 11 of the arm member 1, and again as shown in FIG. S is held. On the other hand, the tool T detached from the main shaft S at the angle position of 232 ° is at the tool changing position P, and the tool T is also held by the holding lever 2 urged by the spring device 3 on the tool holding portion of the arm member 1. 11 is maintained.

Thereafter, the arm member 1 rotates in the opposite direction to the previous one, and the one tool holding portion 11 of the arm member 1 returns from the angular position 232 ° to 180 ° (FIG. 7). As the arm member 1 rotates in the reverse direction, the cam roller 23 at the rear end of each holding lever 2 rides on the projecting portions 41 and 43 of the cam member 4, and the holding lever 2 moves as shown by the arrow U in FIGS. , Rotate to the loosened position. Therefore, the arm member 1 located at the main shaft center A at the angular position of 52 °
The other tool gripper 11 is separated from the tool T, and the holding lever 2 slowly releases the tool T held on the main shaft S. Therefore, the tool T is released from the other tool holding portion 11 of the arm member 1 without applying excessive force to the tool T held on the main shaft S.

On the other hand, as the one tool holding portion 11 of the arm member 1 holding the tool T removed from the main shaft S returns from the angular position 232 ° to 180 °,
The holding lever 2 separates from the tool T and moves to the loosened position, and the tool T is placed at the tool changing position P.
Then, while the main spindle S is being machined, the tool T detached from the main spindle S is replaced by a tool T used in the next step by a tool intermediate transfer device (not shown). Therefore, while in the standby position at the angular position of 180 °, the tool T to be used in the next step is prepared at the tool changing position P, and is ready for the next tool changing sequence. Meanwhile, the other tool gripper 11 of the arm member 1 is at the standby position at the angular position of 0 ° without gripping the tool T and continues to wait until the next tool exchange sequence starts.

As described above, the tool change arm 100 of the present embodiment rapidly turns from the angular position 0 ° to 232 ° once, and then reversely rotates to the angular position 180 ° (that is, during the half rotation). ), Removal of the used tool T from the spindle S, and removal of the tool T used in the next process from the spindle S.
And installation. Further, while one tool gripper 11 of the arm member 1 is at the tool change position P at the angular position of 180 ° and is in the standby state (that is, while the spindle S is working), the used tool T is removed. An operation of exchanging the tool T for use in the next step is also performed. Thus, the tool change can be performed smoothly.

(Effects of the First Embodiment) The tool change arm 100 of the machine tool according to the present embodiment is configured as described above and operates as described above, so that the following effects are exhibited. That is, in short, according to the tool changing arm 100 of the machine tool of the present embodiment, it is possible to change the tool T of the spindle S in an extremely short time, and the working efficiency of the machine tool is improved. This has the effect.

The first reason is that since the arm member 1 is shortened and the turning radius of the tool T is reduced, the inertial force applied to the tool T is suppressed by the angular acceleration and the angular velocity, and the speed is increased more rapidly. This is because turning is possible. The second reason is that, as a result of the rotation radius of the tool changing arm 100 being reduced, the moment of inertia of the tool changing arm 100 is also suppressed to a small value. This is because the tool change arm 100 can be turned.

That is, the arm member 1 having the tool gripping portion 11 at its tip is not provided with the holding lever 2 and is provided externally, so that the length of the arm member 1 is reduced and its mass is reduced. Can be. Further, since the length and mass of the arm member 1 are small, not only the moment of inertia of the arm member 1 is small, but also the holding lever 2 and the spring device 3 are located near the rotation axis of the arm member 1, and the holding lever 2 and the spring device 3 Tool change arm 10 including
The moment of inertia of 0 is small. Further, since the arm member 1 is short, even when the tool T is held by the tool holding portion 11 at the tip thereof, the moment of inertia of the tool changing arm 100 including the tool T is small, so that the angular velocity of the arm member 1 is accelerated / decelerated. Will be done faster. Further, since the arm member 1 is short, the acceleration applied to the gripped tool T is reduced, and the arm can be moved in a short time without applying excessive inertial force to the tool gripping portion 11 of the arm member 1 and the flange of the tool T. The member 1 can be turned. In addition,
The cam member 4 is fixed to the tool change arm base 5,
Since it does not rotate with the arm member 1, no moment of inertia is generated.

Further, in the tool changing arm 100 of the present embodiment, the arm member 1 has a pair of tool gripping portions 11 having a two-fold rotationally symmetric shape and opening in the same rotation direction at both ends. The spring device 3 is equipped with one pair and two pairs. Therefore, while one tool gripper 11 is in a standby state after the tool is mounted on the spindle S,
The other tool holding portion 11 can exchange the tool T at the tool exchange position P, which is reasonable. That is, when one of the tool grippers 11 turns to remove the tool T from the main shaft S and reaches an angle position past the tool change position P, the other tool gripper 11 grips the next tool from the tool change position P. Therefore, the tool T of the main spindle S can be changed only by rotating the arm member 1 about half a turn.

Further, when the arm member 1 is advanced away from the main shaft S when viewed from the main shaft S of the machine tool, the arm member 1 is moved by the lock head 17a as a lock device.
The two holding levers 2 are locked at the tightened position with respect to the tool gripping portions 11 at both ends of the holding lever 2. Therefore, when the arm member 1 is advanced away from the main shaft S, the both holding levers 2 are locked at the tightened positions with respect to the tool holding portions 11 at both ends of the arm member 1, and the tool T is moved to the tool holding portion 11. Since the arm member 1 is not likely to come off, the arm member 1 can be turned more rapidly.

Conversely, when the arm member 1 is retracted toward the main shaft S, the lock head 17a is disengaged from the concave portion 10 of the arm member 1, and the two holding levers 2 are unlocked. In a state where the arm member 1 is retracted toward the main shaft S, the two holding levers 2 are unlocked.
1, the tool T can be removed. In other words, the tool T can be separated from the tool holding portion 11 in a state where the tool T is pushed into the spindle S, and no excessive force is applied at that time.

In addition, when the tool gripping portion 11 of the arm member 1 grips the tool T, the holding lever 2 is appropriately rotated by the cam member 4 and the flange portion of the tool T is attached to the tool gripping portion 11. Accept. Thereafter, the rotation of the pressing lever 2 by the cam member 4 is released, and the pressing lever 2 presses the flange portion of the tool T into the tool holding portion 11 by the action of the spring device 3 and the lock device. Therefore, since unnecessary frictional force and pressing force do not act between the holding lever 2 and the flange portion of the tool T unlike the related art, the turning angular velocity of the arm member 1 is suppressed and the rotation is slowly performed. There is no need to turn. As a result, even when the tool T held on the main spindle S is gripped, the arm member 1 can be rotated at a relatively high speed, and the gripping of the tool T by the tool gripper 11 can be performed smoothly and in a short time. You will be Also,
When the tool T to be replaced is separated from the tool gripper 11,
Since the holding lever 2 opens the tool gripping portion 11 of the arm member 1 by the action of the cam member 4 without applying unnecessary frictional force or pressing force, the action of releasing the tool T can be performed smoothly and in a short time.

As described in detail above, according to the tool change arm 100 of the machine tool of the present embodiment, it is possible to change the tool T of the spindle S in an extremely short time. This has the effect of improving the work efficiency of the work.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing a configuration of a tool changing arm as a first embodiment.

FIG. 2 is a front view showing a configuration of a tool changing arm as the first embodiment;

FIG. 3 is a rear view showing a configuration of a tool changing arm as the first embodiment;

FIG. 4 is a cross-sectional view illustrating a configuration of a holding lever according to the first embodiment.

FIG. 5 is a cross-sectional view illustrating a configuration of a spring device according to the first embodiment.

FIG. 6 is a time chart illustrating the operation of the tool changing arm according to the first embodiment.

FIG. 7 is a schematic diagram illustrating a rotation operation of the tool changing arm according to the first embodiment.

[Explanation of symbols]

100: tool change arm of machine tool 1: arm member 10: concave portion 11: tool holding portion 12: protrusion 13: adjusting screw 14: rotating shaft 15: slide pin 16: shaft member 16a, 16b: through hole 17: lock shaft 17a: Lock head (as a lock device) 18: Sliding ring member 19: Fixing bolt 25: Coil spring 2: Holding lever 20: Pivot part 21: Holding roller (as tip) 22: Ridge 23: Cam roller 3: Spring device 30: Push rod 31: Front end surface 32: Rear end surface 33: Coil spring 4: Cam member 41, 43: Projecting portion 42, 44: Flat portion 5: Tool exchange arm base 50: Internal space 51: External cylindrical member 51a: regulating member A: center of spindle C: center of rotation axis L: center line of arm member P: tool change position S: spindle T: tool ( Rotary tool)

Claims (4)

[Claims] An arm member having a tool gripper portion at a tip thereof which is rotatably driven and forwardly and backwardly driven while being rotatably supported by a rotating shaft, and rotatably supported by the arm member so as to be rotatable; A holding lever having a tip for opening and closing the tool grip of the arm member; a spring device for urging the holding lever in a direction in which the tip grip closes the tool grip; and holding the holding lever in contact with the holding lever. A cam member for rotating the lever, wherein the tool is automatically exchanged between a main spindle that holds and rotates the tool and a tool exchange position where the tool is temporarily placed. Tool change arm of a machine tool. 2. The arm member has a pair of tool gripping portions at both ends which are symmetrical in rotation twice and open in the same rotation direction. The holding lever and the spring device are provided in two pairs. The tool change arm of the machine tool according to claim 1, wherein the tool change arm is provided. 3. The arm member locks both holding levers at positions where the tool grips at both ends of the arm member are closed when the arm member advances away from the main shaft as viewed from the main shaft. 2. A tool changing arm for a machine tool according to claim 1, further comprising a lock device for unlocking both of said holding levers when said arm is retracted toward said main shaft. 4. The holding lever is disposed so as to intersect a line connecting the tool gripping portion of the arm member and the rotation center of the arm member, and has a pivot portion provided on the arm member. The tool exchange arm of the machine tool according to any one of claims 1 to 3, wherein the arm is rotatably supported by the cam member and is opened and closed by the cam member.