JPH065071Y2 - Automatic tool changer - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an automatic tool changer for a machining center,
In particular, the present invention relates to a tool change arm in which a movable claw member can be mechanically locked by an engaging member.

[Prior art]

Generally, a machining center is equipped with an automatic tool changer that automatically changes the tool from the tool magazine to the spindle and from the spindle to the tool magazine. And a movable claw that is provided with a pressing portion for pressing the tool that faces the fixed claw and that is driven to swing by a hydraulic cylinder to switch between a clamp position for gripping the tool and a non-clamp position for not gripping the tool. ing.

For example, in Japanese Patent Application No. 60-94291, a tool carrier provided with a tool changing arm in an automatic tool changing device for a machining center is driven by a hydraulic cylinder at three positions: a changing position, a standby position and a magazine position. What you have done is listed.

[Problems to be solved by the device]

In a conventional automatic tool changer for a machining center, the movable claw of the tool gripping part of the tool changer arm is slidably driven between a clamp position and a non-clamp position by a hydraulic cylinder. Since it is designed to generate a clamping force for gripping
When the hydraulic pressure leaks from the hydraulic cylinder or the hydraulic pressure supply system to the hydraulic cylinder, the clamping force is reduced, and the tool gripped by the tool gripping portion falls, which damages the tool or the work.

An object of the present invention is to realize a tool holding part of a tool changing arm that can mechanically maintain a clamped state even if a hydraulic leak occurs while maintaining the function of clamping and unclamping a tool. Is.

[Means for Solving the Problems]

The automatic tool changer according to the present invention is an automatic tool changer which automatically attaches and detaches a tool to and from a spindle of a machining center by a tool changer arm having at least a pair of claw members for gripping the tool. At least one movable claw member provided in the tool gripper body, having a pressing portion for tool holding at one end, and a movable claw pivotally attached to the tool gripper body at an intermediate portion thereof. A member, a drive rod that is connected to the other end of the movable claw member and that drives the movable claw member to open and close between a non-clamping position and a clamping position, and a member that is pivotally attached to the tool holding body by a pin member. A stop member and an interlocking mechanism for interlockingly connecting the engaging member to the drive rod, wherein the engaging member is attached to the other end of the movable pawl member when the movable pawl member is in the clamp position. Contact The locking position where the movable claw member is mechanically restrained to the clamp position by engaging the movable claw member and the non-lock position where the contact portion of the engaging member does not restrain the movable claw member when the movable claw member is in the non-clamp position. And an interlocking mechanism for switching the contact member of the engaging member at the lock position.
It is configured to shift a predetermined distance to the side opposite to the unlocked position with respect to the perpendicular line extending from the axis of the pin member to the other end of the movable claw member.

[Action]

In the automatic tool changer according to the present invention, when the tool is set between the pair of claw members and the movable rod is switched to the clamp position by the drive rod, the tool is clamped by the pressing portion of the movable claw member. At this time, the engaging member operatively connected to the drive rod by the interlocking mechanism is switched to the lock position, and the abutting portion thereof engages with the other end of the movable pawl member. Is restrained in the locked position. In this locked position, the contact portion of the engagement member is shifted by a predetermined distance to the side opposite to the unlocked position with respect to the perpendicular line from the axis of the pin member to the other end of the movable claw member, so that the locking member is locked. The restrained state at the position is never released, and even if the hydraulic pressure of the hydraulic cylinder that drives the drive rod decreases, the movable claw member is reliably held at the clamp position.

On the other hand, when the movable claw member is driven to the non-clamp position by the drive rod, the engaging member is switched to the non-lock position by interlocking with the drive rod via the interlocking mechanism, so that there is no problem in releasing the clamp.

[Effect of device]

According to the automatic tool changer of the present invention, as described above, the engaging member for mechanically restraining the movable claw member at the clamp position is provided, and the engaging member is interlocked with the drive rod through the interlocking mechanism. With such a simple configuration, it is possible to mechanically restrain the movable claw member at the clamp position, prevent a decrease in the clamping force at the time of hydraulic pressure leak, and prevent the tool from dropping.

Moreover, since the engaging member mechanically restrains the movable claw member at the clamp position via the interlocking mechanism, this restraining force is strong and highly reliable.

Further, in the locked position, the contact portion of the engagement member is shifted by a predetermined distance to the side opposite to the unlocked position with respect to the perpendicular line from the axis of the pin member to the other end of the movable claw member. The locked state at the locked position is not released, and the locked state can be reliably held.

Further, since the movable claw member is directly constrained to the lock position by the engaging member, the structure is simplified.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an automatic tool changer TC provided in a machining center. This automatic tool changer TC is a spindle side position for attaching and detaching a tool to a spindle M of a machining center (not shown) and a tool magazine. Tool T (not shown)
Is mounted on the tool carrier 1 which moves over the magazine side position for mounting and demounting. The above automatic tool changer TC
As shown in FIGS. 1 and 2, the tool carrier 1, the tool exchange arm 10 rotatably mounted on the tool carrier 1, and a hydraulic cylinder for driving the tool exchange arm 10 forward and backward by a predetermined stroke. 2 and rocking lever 3
And a rocking hydraulic cylinder 4, and the tool exchanging arm 10 includes a rocking arm 11 fixed to a piston rod 6 of the hydraulic cylinder 2, and a swing drive hydraulic motor fixed to the tip of the rocking arm 11. 12 and the hydraulic motor 12
And a pair of tool grips 14 provided at the rear end of the support shaft portion 13.

The spline shaft 5 fixed to the base end of the swing lever 3 is inserted and mounted on the piston and the piston rod 6 inside the hydraulic cylinder 2, and the swing lever 3, the piston rod 6, and the swing arm 11 are integrally rotatable. The tip of the rod 4a of the swing hydraulic cylinder 4 is rotatably connected to the tip of the swing lever 3.

Therefore, when the rod 4a of the swing hydraulic cylinder 4 is extended, the swing arm 11 is switched to the exchange position shown by the solid line in FIG. 1 via the swing lever 3 and the hydraulic cylinder 2, and the rod 4a is retracted again. The swing arm 11 is switched to the standby position shown by the phantom line in FIG. When pressure oil is supplied to the head-side oil chamber on the rear side of the hydraulic cylinder 2, the tool exchange arm 10 moves forward with a predetermined stroke together with the piston rod 6, and when pressure oil is supplied to the rod-side oil chamber, as shown in FIG. It is designed to return to the position shown by the solid line.

In the tool exchanging arm 10, a pair of tool grips 14 having a rotational symmetry about the axis of the spindle 13 is provided at the rear end of the spindle 13.
By rotating 2, the pair of tool grips 14 can be rotated 180 ° about the output shaft in the support shaft 13.

Therefore, when automatically exchanging the tool T, for example, the tool carrier 1 is set to the magazine side position and one tool gripping portion 1 is used.
4 grips the desired tool T, moves the tool changing arm 10 forward by a predetermined stroke by the hydraulic cylinder 2, extracts the tool T from the tool magazine, and while the tool carrier 1 is moving from the magazine side position to the spindle side position, hydraulic pressure is applied. Cylinder 2
To return the tool changing arm 10 to the rear side by a predetermined stroke, then move the tool carrier 1 to the position on the spindle side, hold the tool T of the spindle M in the other tool holding portion 14, and move the tool changing arm 10 by the hydraulic cylinder 2. The tool T is pulled out from the spindle M by moving a predetermined stroke forward, and the rod 4a of the swinging hydraulic cylinder 4 is retracted to swing the swinging arm 11.
To the standby position, and at the standby position, the pair of gripping portions 14 are swung 180 ° in the direction of arrow A in FIG. 1 by the turning hydraulic motor 12, and then the rod 4a of the swing hydraulic cylinder 4 is extended to swing. After switching the arm 11 to the exchange position, the tool exchange arm 10 is moved backward by a predetermined stroke by the hydraulic cylinder 2 to mount a new tool T on the spindle M, and then one of the grips 14 is released and then swung. The rod 4a of the hydraulic cylinder 4 for use to retract the swing arm 11
To the standby position.

The series of operations for tool exchange is automatically executed by controlling the hydraulic circuits for the hydraulic cylinders 2 and 4 and the hydraulic motor 12 by the control unit. This hydraulic circuit and control unit are the same as those known in the art, and detailed description thereof will be omitted.

The automatic tool changer TC of the present application is characterized by the structure of the grip portion 14, and the grip portion 14 will be described in detail below.

As shown in FIG. 3 (this shows the state in which the swing arm 11 is in the exchange position), since the pair of gripping portions 14 has a rotationally symmetrical structure, the gripping portion 14 on the upper side will be described. The part main body 20 is provided with a fixed claw 21 (corresponding to one claw member) over a circumference of about 180 ° for receiving the gripped part of the tool T, and the lever is provided on the left side of the grip part main body 20. -Shaped movable claw 22 (corresponding to the movable claw member which is the other claw member) is arranged vertically, and the movable claw 22 is provided with a support shaft 23 oriented in the front-rear direction at a middle portion thereof. Is pivotally attached to the pivot support bracket portion 24 of the fixed pawl 2 and is fixed to the upper end of the movable pawl 22 by the fixed pawl 2
A pressing portion 25 is formed facing the right end portion of the tool 1 to press the gripped portion of the tool T, and a double rod compound for clamping is provided on the left side portion of the gripping portion main body 20 corresponding to the portion near the lower end of the movable claw 22. A dynamic hydraulic cylinder 26 is arranged and fixed in the left-right direction, and the left end portion of the first rod 28 protruding leftward of the cylinder body 27 of the hydraulic cylinder 26 is connected to a portion near the lower end of the movable pawl 22 by a bolt member 30. The second rod 29 projects to the right of the cylinder body 27.

In the connecting structure of the left end portion of the first rod 28 and the movable pawl 22, the movable pawl 22 is provided with the bolt insertion hole 50 and the concave portion 51 into which the left end portion of the first rod 28 is fitted, and the left side of the bolt insertion hole 50. The half portion is formed in the large-diameter bolt insertion hole portion 50a, and the flange portion 30a that can be fitted into the large-diameter bolt insertion hole portion 50a.
A flanged bolt 30 having a threaded shape is inserted into the bolt insertion hole 50 from the left side and screwed onto the left end surface of the first rod 28, and when the left end surface of the first rod 28 abuts on the rear end of the recess 51, the bolt is attached. A predetermined gap is formed between the collar portion 30a of 30 and the rear end of the large-diameter bolt insertion hole portion 50a. Inside the cylinder body 27, the clamp oil chamber 3 is provided on the right side of the piston 31.
2 is also provided with a clamp release oil chamber 33 on the left side, and these oil chambers 32 and 33 are connected to a hydraulic pressure supply device by hydraulic passages (not shown), respectively, to supply pressure oil to the clamp oil chamber 32 to move the piston 31 to the left. When the movable claw 22 is moved to the right, the movable claw 22 swings clockwise around the support shaft 23 and presses the gripped part of the tool T with the pressing part 25 (shown by the solid line in FIG. 3).
When pressure oil is supplied to the clamp release oil chamber 33 to move the piston 31 to the right, the movable pawl 22 swings counterclockwise around the support shaft 23 and the pressing portion 25 grips the gripped portion. Unclamped position away from (shown in phantom in Figure 3)
Can be switched to.

At the intermediate position between the lower end portion of the movable claw 22 and the support shaft 23, the holding portion main body 20 and the movable claw 22 are formed with spring accommodating recesses 34 and 35 which face each other.
A compression coil spring 36 is mounted over 4.35, and the movable pawl 22 is elastically biased toward the clamp position by this spring 36.

When the movable claw 22 is in the clamp device, the movable claw 22 is
A lock mechanism for mechanically restraining the movable claw 22 to the clamp position and not restraining the movable pawl 22 in the non-clamp position is provided as follows.

That is, below the first rod 28, a pair of front and rear bracket portions 2 is provided at a lower portion near the left end of the cylinder body 27.
7a is formed, and an engaging member 37 having a substantially triangular shape in a front view and having a predetermined plate thickness is provided in a direction orthogonal to the paper surface of FIG. 3, and the engaging member 37 has both brackets 27a in the vicinity of the first apex thereof.
It is rotatably mounted around the pin member 38 by being inserted in between and pivotally supported on both brackets 27a by the pin member 38 oriented in the front-rear direction, and the second top portion of the engaging member 37 is in the clamp position and is movable. An abutting portion 40 that abuts the engaging portion 39 at the lower end of the claw 22 is provided. The engagement member 37 is shown by a solid line in the locking position shown in FIG.
In order to switch to the unlocked position shown by the rotated virtual line, a rod insertion hole 41 is provided at the lower end of the cylinder body 27 in the left-right direction, and the rod member 42 is loosely fitted in this rod insertion hole 41. And the right end of the rod member 42 is outside the cylinder body 27.
Of the second rod 29 is integrally connected to the right end of the second rod 29 through a connecting plate 43, and the left end of the rod member 42 has a pin 44 in the front-rear direction fixed to the left end of the rod member 42 and a long hole 45 at the third top of the engaging member 37. It is loosely connected to the third top by being loosely fitted to.

Incidentally, the connecting plate 43, the bolt 29a described later, the bolt 4 described later
2a, rod member 42, pin 44, long hole 45,
An interlocking mechanism is configured.

When pressure oil is supplied to the clamp oil chamber 32 of the hydraulic cylinder 26 to move the piston 31 leftward and the left end of the first rod 28 presses the rear end of the recess 51 to switch the movable pawl 22 to the clamp position. In conjunction with this, the rod member 42 moves to the left and the engaging member 37 rotates clockwise to switch to the lock position.
The engaging member 37 is configured to abut the engaging portion 39 at a position above the axis of 8 by a dimension a and mechanically lock the movable pawl 22.

That is, in the lock position, the contact portion 40 of the engagement member 37 is located at a predetermined small distance (opposite to the unlocked position) with respect to the perpendicular line from the axis of the pin member 38 to the other end of the movable claw 22 ( Since the above dimension a) is configured to shift,
At the locked position, the mechanical locking of the movable claw 22 by the engagement member 37 is not released.

When supplying pressure oil to the unclamping oil chamber 33 of the hydraulic cylinder 26 to move the piston 31 to the right, the second
The engaging member 37 is forcibly driven to rotate toward the unlocked position via the rod 29, the connecting plate 43, and the rod member 42 to be switched to the unlocked position.

As is clear from FIG. 3, the engaging portion 39 of the movable claw 22 and the engaging member 37 do not interfere with each other when the engaging member 37 is switched to the unlocked position, and In order to avoid interference at this time, the engaging portion 39 is formed in a step-down shape to the left of the next step.

Further, in order to firmly connect the second rod 29 and the rod member 42, the right end portion of the second rod 29 is fitted into the fitting hole of the connecting plate 43, and the second rod 29 and the connecting plate 43 are connected by the bolt 29a. The rod member 42 is firmly fixed to the connecting plate 43 with a bolt 42a.

Next, in the configuration of the gripping portion 14 of the tool exchanging arm 10, when gripping the tool T, the fixed claw 2 is fixed to the gripped portion of the tool T while the movable claw 22 is held in the non-clamping position.
When the movable claw 22 is switched to the clamp position after the first claw 1 is fitted to the tool 1, the pressing portion 25 and the fixed claw 21 can grip the tool T.

When the movable pawl 22 is switched to the clamp position, the engaging member 37 is automatically switched to the lock position as described above, and the contact portion 40 is located above the axial center of the pin member 38 by a predetermined small distance (dimension a). Since it abuts on the engaging portion 40 at the position of M, even if the hydraulic pressure in the clamp oil chamber 32 of the hydraulic cylinder 26 decreases due to a hydraulic leak or the like, the movable claw 22 keeps the engaging member 3
Since the mechanically locked state is held at the clamp position by 7, it is possible to prevent the tool T from falling off.

When pressure oil is supplied to the clamp release oil chamber 33 of the hydraulic cylinder 26 to drive the piston 31 to the right in order to switch the movable pawl 22 from the clamp position to the non-clamp position, the flange portion 30a of the bolt 30 is inserted into the large diameter bolt. Only the piston 31 moves to the right with the movable pawl 22 in the clamped position until it abuts against the rear end of the hole 50a.
The engaging member 37 is switched to the unlocked position via the connecting plate 43, the rod member 42, and the pin member 38, and the collar portion 30
When a comes into contact with the rear end of the large-diameter bolt insertion hole 50a, the movable claw 22 is pulled rightward by the first rod 28 and switched to the unclamped position.

As described above, while maintaining the clamp function and the unclamp function of the movable claw 22, the hydraulic cylinder 26 for clamping drives the engaging member 37 to mechanically lock the movable claw 22 in the clamp position. Is possible.

The shape and structure of the engaging member 37 are not limited to those shown in the drawings, and for example, the engaging member 37 may be pivotally supported by a vertically oriented pin member or a horizontally oriented pin member. Also, the engaging member 37 may be configured as a link type with a plurality of members, and the connecting structure between the engaging member 37 and the rod member 42 may be configured by a cam or a spring. Furthermore, it is possible to omit the rod member 42 and the connecting plate 43 and connect the engaging member 37 and the first rod 28.

In addition to the above-described embodiment, a gripping portion of a type in which the gripped portion of the tool T is sandwiched by a pair of pressing portions of the movable claws,
The locking mechanism of the above embodiment can be similarly applied.

[Brief description of drawings]

1 is a front view of an automatic tool changer, FIG. 2 is a plan view of the same, and FIG. 3 is an enlarged vertical sectional view of a grip portion. M ... Spindle, TC ... Automatic tool changing device, 10 ... Tool changing arm, 14 ... Gripping portion, 20 ... Gripping portion main body, 2
1 ... Fixed claw, 22 ... Movable claw, 23 ... Spindle, 25 ...
... Pressing part, 26 ... hydraulic cylinder, 28 ... first rod, 29 ... second rod, 37 ... engaging member, 38 ...
Pin member, 40 ... Contact portion, 42 ... Rod member, 43
...... Connecting plate, 44 ...... pin.

Claims (1)

[Scope of utility model registration request] 1. An automatic tool exchanging device for automatically attaching and detaching a tool to and from a spindle of a machining center by a tool exchanging arm having at least a pair of claw members for grasping a tool, wherein a tool grasping part main body of the tool exchanging arm is provided. At least one movable claw member provided, wherein the movable claw member has a pressing portion for pressing a tool at one end, and is pivotally attached to a tool gripping part main body at a midway portion thereof, A drive rod that is connected to the other end of the claw member and that drives the movable claw member to open and close between a non-clamping position and a clamping position; and an engaging member that is pivotally attached to the tool gripping body by a pin member. An interlocking mechanism for interlockingly connecting the engaging member to a drive rod, wherein the engaging member engages an abutting portion of the engaging member with the other end of the movable pawl member when the movable pawl member is at a clamp position. Movable claw An interlocking mechanism that switches between a locked position for mechanically restraining the member to the clamp position and a non-locked position where the contact portion of the engaging member does not restrain the movable pawl member when the movable pawl member is in the non-clamp position. In the lock position, the contact portion of the engagement member shifts a predetermined distance to the side opposite to the unlock position with respect to the perpendicular line from the axis of the pin member to the other end of the movable claw member. An automatic tool changer characterized in that