JPH08108334A - Tool holding device for machine tool - Google Patents

Abstract

PURPOSE: To secure the force for gripping a tool so as to eliminate the fall-out of the tool by hindering the movement of one side member of a grip in the opening direction with the other side member of the grip even in the case where the force in the opening direction is applied to one side member of the grip in the condition that a grip holding a tool is positioned in the horizontal direction. CONSTITUTION: Since a protruded and a recessed parts 33 respectively formed on the inside surfaces of arm members 14a, 14b of a grip, which are opposite to each other, are engaged with each other, even in the case where the force in the opening direction is applied to the only one member 14b by the self-weight of a tool and the one member 14b tries to be turned in the condition that a grip holding a tool is positioned in the horizontal direction, turning thereof is hindered by the other member 14a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holding device such as a machine tool or a robot having a function of automatically changing tools.

[0002]

2. Description of the Related Art Conventionally, there are machine tools and robot arms having an automatic tool changing function, which are equipped with a tool holding device (hereinafter referred to as a magazine) for holding a tool to be replaced. By exchanging tools between the machine and the spindle head of the machine tool, the tools are exchanged. An example of such a tool gripping device is shown in FIGS. FIG. 5 is a front view of the magazine, and FIG. 6 is a side view of one grip thereof. Magazine 15
Tool holder 5a, which is based on a disk-shaped member that can be swung
A plurality of grips 30 for holding (or a tool) are radially provided. The grip 30 has a pair of arm-shaped members 30a and 30b as a base, and is rotatably provided around a support shaft 31, and the arm-shaped member 3 is provided.
The spring 32 inserted between the arms 0a and 30b on the side opposite to the tool holding side is biased in the direction in which the arm-shaped member on the tool holding side is closed, that is, in the direction in which the tool holder 5a is gripped. .

[0003]

However, in the conventional tool gripping device as described above, in the turning state in which the grip 30 holding the tool is positioned in the horizontal direction, the weight of the tool causes one of the lower grips to move. Arm-shaped member 30
A force acts in the opening direction (downward) of a and 30b, and a force acts in the closing direction (downward) of the other upper arm-shaped member.
That is, the grasping portions of both of them move downward and their positions are displaced. In this case, as a result, the repulsive force does not act on the spring 32 provided for holding the tool, the force for holding the tool is not strong, and the tool may fall.
That is, in the pair of grips 30, when a force acts on both arm-shaped members 30a and 30b in the opening direction, a repulsive force acts on the spring 32 provided to hold the tool, but When a force in the opening direction acts on only one of the members 30a and 30b, the other arm-shaped member 30
Since a and 30b work in the closing direction, there is a problem that the force for holding the tool by the spring 32 does not work. The present invention has been made in order to solve the above problems, in a state where the grip holding the tool is positioned in the horizontal direction, etc., the force in the opening direction is applied only to one side member of the pair of grips holding the tool. Even if it works, the other side member prevents movement of the former member in the opening direction,
An object of the present invention is to provide a tool gripping device for a machine tool in which the force for gripping the tool is retained and the tool does not drop.

[0004]

In order to achieve this object, the invention of claim 1 is a tool gripping device for a machine tool having a grip for gripping a tool in an exchangeable manner, and the grip transfers the tool. As described above, the tool gripping portion is composed of at least a pair of arm-shaped members that are configured to be opened and closed, and the concavo-convex portions that engage with each other are formed on the inner surfaces of the arm-shaped members that face each other.
According to a second aspect of the present invention, in the tool holding device for a machine tool according to the first aspect, the grip is provided with a biasing force in a direction in which the tool holding portion is always closed, and one arm-shaped member of the grip. When a force acts in the direction to open only,
The concavo-convex portion has an interlock function. According to a third aspect of the present invention, in the tool holding device for a machine tool according to the first or second aspect, when the grip is in a laterally oriented posture position, the arm-shaped member located on the upper side is lifted upward. When the tool gripping portion is opened, the concavo-convex portions do not engage with each other.

[0005]

According to the tool-holding device for a machine tool of the first aspect of the present invention having the above-mentioned structure, the gripper carries out the tool delivery by opening and closing the tool-holding portions of the pair of arm-shaped members. Since the concavo-convex portions formed on the inner side surfaces of the arm-shaped member which face each other are engaged with each other, only one member is affected by the self-weight of the tool when the grip holding the tool is positioned in the horizontal direction. Even if a force in the opening direction acts to turn it, the turning is blocked by the other member. Further, according to the tool gripping device for a machine tool of claim 2, the grip is provided with a biasing force in a direction in which the tool gripping portion is always closed, and a force is applied in a direction in which only one arm-shaped member of the grip is opened. When actuated, the interlocking function is exerted by the engagement of the concave and convex portions formed on both arm-like members, and the other member also exerts a force in the direction in which it is forcibly opened, and the repulsive force of the above-mentioned biasing force acts to grip the tool Power is secured. Further, according to the tool gripping device of the machine tool of claim 3, when the arm-shaped member located on the upper side is lifted upward to open the tool gripping portion when the grip is in the posture position in which the grip is oriented in the lateral direction, Since the concave and convex portions of the arm-shaped member do not engage with each other, the tool can be manually removed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A machine tool equipped with a tool gripping device for exchanging tools according to an embodiment of the present invention will be described below with reference to the drawings. 1 is a side view showing the overall configuration, FIG. 2 is a front view of a tool gripping device (magazine device), and FIG. 3 is a side view of one grip portion in the magazine device. The machine tool 1 is for performing cutting and other work in a horizontal direction (left and right in the drawing) on a work (not shown), and a vertical direction with respect to a column 2 provided so as to be movable in the front-back and left-right directions. A spindle head 3 movably provided to the column 2, and a magazine device 4 movably in the front-rear direction with respect to the column 2 and rotatably provided for automatic tool change. Spindle head 3
Is vertically driven by a ball screw (not shown) provided on the column 2 side. This spindle head 3 has a holder part 5 for holding and clamping a tool holder 5a (FIG. 2) at its tip, and a spindle shaft (main shaft) 6 that is driven to rotate, and a spindle motor 7 that drives this spindle shaft 6 to rotate. And a part of the unclamp mechanism 8 for releasing the clamp of the tool.

As a member constituting the unclamp mechanism 8, a rod 9 is inserted into a hollow portion of the spindle shaft 6 so as to be movable in parallel with the shaft, and is urged by an unclamp spring (not shown), and the spindle shaft 6. An unclamp ring 10 fitted to the outer periphery of the rod 9 and connected by a pin at the rear end side of the rod 9 is provided on the spindle head 3 side. As other members constituting the unclamp mechanism 8, an unclamp lever 12 rotatably supported by a fulcrum base 11 on the column 2 side and the unclamp lever 1 are provided.
2 and the cam 13 that drives the rotation of the column 2 within a predetermined angle,
It is provided on the side. The upper end portion (dotted line portion) of the unclamp lever 12 has a cam groove 13 a for unclamping the cam 13.
The unclamp lever 12 is rotated by the rotation of the cam 13. The lower end of the unclamp lever 12 has an opening 3 formed in the exterior cover of the spindle head 3.
When the spindle head 3 rises, it comes into contact with the side end surface of the unclamp ring 10 and comes into contact with the side end surface of the unclamp ring 10. The cam drive causes the unclamp lever 12 to rotate as indicated by the chain double-dashed line. , The unclamp ring 10 is pushed forward, whereby the clamped state of the tool can be released.

The magazine device 4 has a disk-shaped magazine 15 in which a plurality of grips 14 for holding tools are radially arranged, and the magazine 15 is rotatably supported by a magazine support portion 16 fixed to the column 2 side. It is held by a rotating shaft 17 that is rotated, and is movable in the horizontal direction by a spline formed on the rotating shaft 17, and is rotated together with the shaft 17. The rotary shaft 17 has a reduction gear mechanism 18 and a drive shaft 19 and a magazine rotation motor 2
Connected to 0. As shown in FIGS. 2 and 3, each of the grips 14 for holding the tool is rotatably supported by the support shafts 31, 31 on the disc-shaped base material of the magazine 15, and the spring 32 is provided in the direction in which the tool gripping portion is closed. It is provided with two openable and closable arm-shaped members 14a and 14b. Then, the concavo-convex portions 33 which engage with each other and have an interlock function are formed on the inner surfaces of the arm-shaped members 14a and 14b which face each other.

Further, the magazine 15 of the magazine support portion 16
A positioning pin 21a for stopping the magazine 15 at a predetermined indexing and turning position is provided on the surface facing to, and the positioning pin 21a is provided on the back surface of the magazine 15.
Positioning holes 21b into which a plurality of grips 1 can be fitted
4 are provided at positions corresponding to the respective four. Then, when the indexed magazine 15 is retracted for tool replacement, the positioning pin 21a moves into the positioning hole 2
The magazine 15 is accurately positioned by fitting in the 1b. Further, the magazine 15 is provided with a lock mechanism 22 having a tapered lock member for normally locking the grip 14 in the closing direction, and the lock is released only at a predetermined rotation position such as a position for tool change. It is supposed to be done. The lower side of the magazine 15 in FIG. 1 shows the unlocked state.

Further, as a mechanism for moving the magazine 15 in the front-rear direction for tool change, a front-rear shaft shaft 23 supported by a cam base 16a attached to the magazine support portion 16 so as to be movable back and forth, and the front-rear shaft. It has a front and rear lever 24 for moving the shaft 23 back and forth. The front-rear lever 24 is rotatably supported on the top plate of the cam base 16a, and a cam follower (not shown) fastened to one end thereof is fitted in a front-rear cam groove 13b of the cam 13 and a cam follower 24a fastened to the other end. Are engaged with front and rear cam members 25 coupled to the front and rear shaft shafts 23. The cam followers 23a fastened to the front end portions of the front and rear shaft shafts 23 are provided in the cam groove 2 provided integrally with the magazine 15.
6, so that the longitudinal movement of the shaft shaft 23 is transmitted to the magazine 15. Further, the integrated cam 13 provided with the unclamping cam groove 13a and the front-rear cam groove 13b is connected to a cam drive motor (not shown) via the cam shaft 27, and the rotational position of the cam 13 can be changed. The rotation is controlled on the basis of a signal from a cam sensor (not shown) for detection. The cam 15 drives the magazine 15 in the front-rear direction via the front-rear lever 24. The front-rear cam member 25 'indicated by a chain double-dashed line indicates the position when it moves forward.

Next, the automatic tool changing operation of the machine tool configured as described above will be described. When the automatic tool change operation is started, the spindle head 3 moves up, and the unclamp lever 12 can come into contact with the unclamp ring 10. At this time, the holder portion 5 of the spindle shaft 6 on the spindle head 3 side is held. The clamped tool holder is transferred to the grip 14 of the magazine 15. Further, the cam drive motor is driven to rotationally drive the cam 13 via the cam shaft 27, the cam follower at the upper end of the unclamp lever 12 is tilted in the unclamping cam groove 13a, and the unclamp lever 12 is moved to the fulcrum base 11. The cam follower at the lower end pushes the side end surface of the unclamp ring 10, the rod 9 is moved against the bias by the unclamp spring, and unclamping is performed.

Further, the cam followers at one end of the front and rear levers 24 are caused by the inclination of the magazine front and rear cam grooves 13b, the front and rear levers 24 start to move, and the cam followers 24 at the other ends.
a pushes the front-rear cam 25 and advances the front-rear shaft shaft 23. As a result, the cam follower 23 a at the tip of the front and rear shaft shaft 23 advances the magazine 15 via the cam groove 26. After that, the magazine rotation motor 20 rotates, the magazine 15 is rotated through the spline of the reduction gear mechanism 18 and the rotation shaft 17, and the stop position is determined. After the indexing is completed, the cam 13 is reversed by rotating the cam drive motor in the reverse direction. As a result, the reverse operation is performed in the reverse order of the above operation. That is, the indexed magazine 15
Is retracted, the tool holder 5a (FIG. 2) is passed from the magazine 15 to the holder portion 5 on the spindle head 3 side, and the clamping is performed.

Next, the operation of the grip 14 will be described. The arm-shaped members 14a and 14b are biased in the closing direction by the compression spring 32, and hold the tool holder 5a. When the magazine 15 is rotated and the grip 14 is oriented in the horizontal direction, the weight of the tool holder 5a acts only on the lower arm-shaped member 14b (in the case of FIG. 3) of the grip 14, This lower arm member 14
b tends to move in the opening direction and the upper hummed member 14a tends to move in the closing direction. However, the arm-shaped member 14
Since the uneven portions 33 of the a and 14b are engaged with each other, an interlock function is exerted, and a force acts in the direction in which the upper arm member 14a is forcibly opened, so that the repulsive force of the compression spring 32 is reduced. The grip 14 secures a force sufficient to grip the tool. Therefore, the tool holder 5a held by the grip 14 does not drop. In addition,
A rotary roller 34 is attached to the tip ends of the arm-shaped members 14a and 14b for facilitating the loading and unloading of the tool holder 5a.

As described above, the grip 1 of the magazine 15
In the configuration in which 4 includes the lock member 22 that locks the state in which the tool holder 5a is gripped, the lock of the lock member 22 must be unlocked in the turning position where the tool holder 5a can be manually taken out or attached. . In such a case, if the arm-shaped members 14a and 14b are engaged with each other by the concave-convex portion 33, as in the above-described embodiment, when the tool holder 5a is manually taken out, one arm-shaped grip 14 is removed. Member 14a or 1
If the pulling-out method is such that only 4b moves, the interlock is applied as described above, and therefore both arm-shaped members 14a and 14b must be pulled straight out (radially) so as to move in the same manner. Therefore, it is difficult to take it out manually.

Therefore, in order to solve such a problem,
As in the modified example shown in FIG. 4, when the arm-shaped members 34a and 34b of the grip of the magazine 15 are directed to the right, the interlock is locked only when the lower arm-shaped member 34b is moved in the opening direction. The uneven portion 35 may be provided. That is, the concave-convex portion 35 does not engage with each other when the upper arm-shaped member 34a is lifted upward to open the tool gripping portion. With such a configuration, the operator manually operates the tool holder 5a.
When replacing the tool, the tool can be easily replaced by pulling it out while lifting the tool holder 5a. The present invention is not limited to the configuration of the above-described embodiment, and various modifications can be made.

[0016]

As described above, according to the tool gripping device for a machine tool of the first aspect of the present invention, since the uneven portion formed on the arm-shaped member of the grip is engaged, the grip holding the tool is In a state where the tool is positioned in the horizontal direction, even if a force in the opening direction acts on only one member due to the weight of the tool and it tries to rotate, the other member prevents the rotation, so the gripping force Holds and the tool does not fall. Further, according to the tool gripping device for a machine tool of the invention of claim 2, in addition to the above effect, the grip is always biased in the closing direction, and only one of the arm-shaped members opens. Even if a force acts in the direction, the interlock function works due to the engagement of the concave and convex portions of both arm-like members, and the force also acts in the direction in which the other member opens. Therefore, the repulsive force of the urging force acts, and the force for gripping the tool is secured. According to the tool gripping device for a machine tool of the third aspect of the present invention, in addition to the above effects, when the grip is in the lateral posture position, the upper arm-shaped member is lifted upward to raise the tool gripping portion. When is opened, the concave and convex portions of the arm-shaped member are prevented from engaging with each other, so that the tool can be easily replaced manually.

[Brief description of drawings]

FIG. 1 is a side sectional view of a machine tool having a tool gripping device according to an embodiment of the present invention.

FIG. 2 is a front view of the same device.

FIG. 3 is a side view of one grip in the same device.

FIG. 4 is a side view showing another embodiment of the grip in the same device.

FIG. 5 is a front view of a conventional tool gripping device.

FIG. 6 is a side view of one grip of a conventional tool gripping device.

[Explanation of reference numerals] 1 machine tool 4 magazine device 5 tool holder 14 grips 14a, 14b arm-shaped member 15 magazine 32 compression spring 33 uneven portions 34a, 34b arm-shaped member 35 uneven portion

Claims (3)

[Claims] 1. A tool gripping device for a machine tool having a grip for gripping a tool in an exchangeable manner, wherein at least one pair of grips is configured such that the tool gripping portion can be opened and closed so as to transfer the tool. A tool gripping device for a machine tool, comprising: an arm-shaped member, and concave and convex portions that are engaged with each other formed on each of inner facing surfaces of the arm-shaped member. 2. The urging force is applied to the grip in a direction in which the tool gripping portion is always closed, and when the force acts only on one arm-shaped member of the grip in the opening direction, the concave-convex portion is interleaved. The tool gripping device for a machine tool according to claim 1, wherein the tool gripping device has a lock function. 3. When the grip is in a laterally-oriented posture position, when the arm-shaped member located on the upper side is lifted upward to open the tool grip portion, the concave-convex portions do not engage with each other. The tool gripping device for a machine tool according to claim 1 or 2, wherein the tool gripping device is configured in such a relationship.