JPH07246584A - Automatic tool change device - Google Patents

Abstract

PURPOSE:To provide an automatic tool change device which can correct an error of the position and the attitude generated in the assembly work, when a part is positioned and inserted by using 811 industrial robot. CONSTITUTION:This automatic tool change device consists of the first unit 1 having a pulse motor 3 and a locking mechanism 4, and the second unit 2 having a hook 5, and while the locking mechanism 4 is made in the locking condition to the hook 5 by the rotation of the output shaft 30 of the pulse motor 3, the contact surfaces of the first and the second units 1 and 2 are to be made in the adhered condition each other, or in the condition generating a minute clearance, while maintaining the locking condition by controlling the rotating amount of the output shaft 30. Only when a force more than a specific value is operated to the second unit 2 side, under the condition generating a minute clearance between the contact surfaces of the first and the second units 1 and 2, the second unit 2 is displaced three-dimensionally to the first unit 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changer attached to an output part of an industrial robot such as a so-called manipulator.

[0002]

2. Description of the Related Art When a part is positioned and inserted by an industrial robot equipped with an automatic tool changer, a device (hereinafter, referred to as a floating device) for correcting an error in position and orientation that occurs during assembly work is a robot body. Had to be installed between the tool changer and the tool changer.

Here, the floating device is composed of a plate member attached to the robot body side, a plate member attached to the automatic tool changing device side, and a displacement absorbing member provided between these two plate members. Due to the presence of the displacement absorbing member, an error in the three axial directions between the plate materials can be absorbed and corrected.

However, since the floating device has a constant thickness, the length from the robot body to the work becomes large, and the displacement of the above two plates is prevented in order to move the industrial robot at high speed. It was necessary to have a locking mechanism. Therefore, there is a problem that the inertial force acting on the robot body becomes large and the apparatus itself becomes expensive.

In recent years, even if a floating device having the above-mentioned problems is not used, it is possible to correct the position and orientation errors that occur during assembly work when parts are positioned and inserted by an industrial robot. Development of an automatic tool changer is desired.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention provides an automatic tool changer capable of compensating for errors in position and orientation that occur during assembly work when parts are positioned and inserted by an industrial robot. It is an issue.

[0007]

SUMMARY OF THE INVENTION The present invention is an automatic tool changer comprising a first unit having a drive mechanism and a locking mechanism and a second unit having a hooking portion, the output section of the drive mechanism. The locking mechanism is brought into a locked state by the displacement of the hook portion, and while the locked state is maintained by controlling the displacement amount of the output portion, the mutual joining surfaces of the first and second units are It is designed so that it can be in a close contact state or a state in which a minute gap is formed. In the state in which there is a gap between the joining surfaces of the first and second units, a certain amount of force acts on the second unit side. Only then is the second unit displaced in the three-dimensional direction relative to the first unit.

Also, the present invention is an automatic tool changer comprising a first unit having a pulse motor and a locking mechanism and a second unit having a hooking portion, which is engaged by rotation of the output shaft of the pulse motor. The stop mechanism is locked to the hooking portion, and the locked state is maintained by controlling the rotation amount of the output shaft, and the joining surfaces of the first and second units are in close contact with each other. It is designed so that a minute gap can be formed, and only when a certain amount of force acts on the second unit side with a gap formed between the joint surfaces of the first and second units. The unit is displaced in the three-dimensional direction with respect to the first unit.

Further, in the above automatic tool changer, at least one of the joint surfaces of the first and second units is provided with elastic biasing means for pressing the joint surface of the other unit. The displacement of the second unit in the three-dimensional direction with respect to the first unit in the state where a gap is formed between the joint surfaces of the two units is performed against the biasing force of the elastic biasing means.

[0010]

The present invention operates as follows.

In the automatic tool changing device of the present invention, the driving mechanism (pulse motor) is driven to bring the locking mechanism and the hooking portion into the locked state, and the second unit is connected to the first unit. Becomes

The device maintains the locked state by controlling the displacement amount of the output portion (rotation amount of the output shaft), and the joint surfaces of the first and second units are in close contact with each other (hereinafter, Since it is possible to make a state in which the robot is in close contact with one another and a state in which a minute gap is formed (hereinafter referred to as a gap state), when the robot positions and inserts the parts, the gap state is set and the robot moves at high speed. In the case of performing the above or in the case of performing work other than the above-mentioned positioning and insertion, the above-mentioned close contact state may be established. That is, in the above gap state,
The device itself has a correction function of the floating device, and when in a close contact state, the device itself has a lock function.

Therefore, when this automatic tool changer is used, it is not necessary to provide an expensive floating device, and therefore the inertial force acting on the robot is not increased.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings shown as embodiments.

The automatic tool changer of this embodiment is used by being attached to the arm end of a manipulator. As shown in FIG. 1, it basically has a pulse motor 3 and a locking mechanism 4 and a robot. It is composed of a first unit 1 mounted on the side and a second unit 2 on the work side having a hooking portion 5 and having a tool mounted thereon. This first
The joint surfaces of the second units 1 and 2 are provided with male / female connectors (not shown) for connecting electric / air / oil / water paths, and in order to properly connect the male / female connectors, As shown in FIG. 1 and FIG. 5, a guide hole 7 and a taper pin 6 to be inserted therein are provided.

In this type of apparatus, a large number of second units 2 having different tools are prepared, and when one process is completed and the next process is performed, the second unit 2 which has been used until now is used as the second unit 2. One unit 1 is removed and a second unit 2 having another type of tool is joined.

The structure of the main part of this automatic tool changer will be described below. [Regarding Configuration of First Unit 1 ] The first unit 1 is
As shown in FIG. 1, it is formed in a thick disk shape, and accommodates the pulse motor 3 inside and also has a locking mechanism 4 on the lower surface thereof. As shown in FIG. 2 and FIG. The locking mechanism 4 is brought into a locked / unlocked state with a hook portion 5 described later by the forward and reverse rotations of the output shaft 30 of 3.

The output shaft 30 of the pulse motor 3 rotates by a number corresponding to the number of pulses input to the pulse motor 3. As shown in FIGS. 2 and 3, the output shaft 30 has a female screw portion. Has been formed.

The locking mechanism 4, as shown in FIG. 1 and FIG.
A pair of hanging pieces 40 hanging from the lower surface of the first unit 1,
40, the fixing pins 41, 41 laid between the portions near the both ends of the hanging pieces 40, 40, and the hanging piece 4
H-shaped elevation body 42 in plan view arranged between 0 and 40
And a pair of locking levers 43, 43 which are swingably attached to the elevating body 42 via pins, and the fixing pin 41 is attached to a long hole 43a formed in the locking lever 43. While being inserted, the male screw portion of the output shaft 30 is screwed into the female screw portion formed at the center of the elevating body 42.

On the lower surface side of the first unit 1,
As shown in FIG. 1 and FIG.
Two taper pins 6 are provided at an interval of 0 °, and each taper pin 6 is composed of a same diameter portion 60 having a diameter slightly smaller than the diameter of the guide hole 7 and a taper portion 61 connected to the same diameter portion 60. As shown in FIG. 5, a gap g is formed between the same diameter portion 60 of the taper pin 6 and the guide hole 7, but when the taper pin 6 is inserted into the guide hole 7, the gap g is formed. Regardless of the formation position, the male / female connectors for connecting the electric / air / oil / water paths are properly connected. Further, as shown in FIG. 2 and FIG. 3, three plungers 8 are provided at 120 ° intervals on the lower surface side of the first unit 1, and the plunger 8 is provided with a steel ball 80 that can be retracted from the lower surface. Is configured to be urged by a spring 81 in a protruding direction. [Regarding Configuration of Second Unit 2 ] The second unit 2 is
As shown in FIG. 1, there is provided a through hole 20 having a rectangular shape in plan view which is open to the upper and lower surfaces, and the through hole 20 has a size sufficient to accommodate the locking mechanism 4 and corresponds to the short side. Hook portions 5 are provided on the constituent walls of the through holes 20, respectively.

Incidentally, various tools can be attached to the lower surface of the second unit 2. [Connection / separation / gap between the first and second units 1 and 2
Connections Having ] (1) Connection Between First and Second Units 1 and 2 When a predetermined number of pulses are applied to the input part of the pulse motor 3 and the output shaft 30 is rotated in the reverse direction (counterclockwise), 42
Is guided by the hanging pieces 40, 40 and moves downward without rotating. Along with this, the locking levers 43, 43 are changed from the C-shape as shown in FIG. 2 to the state of a straight line shown in FIG. 3, and as shown in FIG. Is in a locked state, and the joint surfaces of the first and second units 1 and 2 are in contact with each other.

Therefore, in this state, the robot can move at high speed. (2) Separation between the first and second units 1 and 2 When a predetermined number of pulses are applied to the input part of the pulse motor 3 to rotate the output shaft 30 in the forward direction (clockwise), the lifting body 42 causes the hanging piece 40 to move. , 40 to move upward without rotating. Along with this, the locking levers 43, 43 are
As shown in FIG. 2, the straight line shown in FIG. 2 has a V-shape, and the locking levers 43, 43 and the hooks 5 are unlocked, and the first and second units 1, 1. Two
It becomes possible to separate from each other.

Therefore, the second with other types of tools
Exchange with the unit 2 is possible. (3) Connection with a minute gap between the first and second units 1 and 2 From the state of (2) above, a pulse of a number smaller than the above-mentioned predetermined number is applied to the input part of the pulse motor 3 to output the shaft 30.
When the rotation is reversed, the elevating body 42 stops slightly above the state (1). In this state, the locking levers 43, 4
No. 3 is not in a straight line state as shown in FIG. 6, but the second unit 2 is the plunger 8 of the first unit 1.
Of the locking levers 43, 4 pushed down by the steel ball 80 of
3 and the hook portion 5 are in a locked state. That is, the joint surfaces of the first and second units 2 are in a state in which minute gaps G are evenly formed over the entire circumference as shown in FIG. Since the second unit 2 is pushed down at three points by the steel balls 80 of the plunger 8 on the first unit 1 side, the second unit 2 does not rattle with respect to the first unit 1. ing.

Therefore, when the part P is positioned and inserted, even if the axial center of the part P and the central axis of the hole H are misaligned as shown in FIG. 7, the second unit 2 is Inclining with respect to the first unit 1, FIG.
As shown in, the part P can be inserted into the hole H without difficulty. The displacement of the second unit 2 with respect to the first unit 1 is possible in the three-dimensional direction.

The locking mechanism 4 of the above embodiment can be replaced with the locking mechanism shown in FIGS. 10 and 11.

As shown in FIGS. 10 and 11, this locking mechanism is of a type in which the cams 91, 91 are synchronously rotated in the forward and reverse directions by the pulse motor 3 via the rack and pinion mechanism 90. The cam surface of the cam 91 gradually changes the distance from the center of rotation (a dimension <b dimension).

Therefore, in this type of locking mechanism, the rotation angle of the cams 91, 91 changes according to the rotation amount of the pulse motor 3, and the distance relationship between the cam surface and the pin-shaped hooking portion 5 changes, which causes A minute gap G is formed between the first unit 1 and the second unit 2.

Further, although the pulse motor is used as the drive mechanism in the above embodiment, the invention is not limited to this, and a cylinder utilizing air pressure or hydraulic pressure may be used. In short, it suffices to control the displacement amount of the output portion of the drive mechanism so that the joint surfaces of the first and second units are in close contact with each other and the state in which a minute gap is formed. . When a cylinder is used as the drive mechanism, the amount of expansion / contraction of the output shaft of the cylinder may be controlled using a sensor or the like.

[0029]

The present invention having the above-mentioned structure has the following effects.

From the contents of the above-mentioned action column, it is possible to provide an automatic tool changer capable of correcting an error in the position and the posture which occurs during the assembly work when the parts are positioned and inserted by the industrial robot.

[Brief description of drawings]

FIG. 1 is an external perspective view of an automatic tool changer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the automatic tool changer, showing a state in which a first unit and a second unit are separated from each other.

FIG. 3 is a cross-sectional view of the automatic tool changer, showing a state in which a first unit and a second unit are connected.

FIG. 4 is a view of the first unit as seen from below.

FIG. 5 is a view showing a relationship between a taper pin provided on a lower surface of the first unit and a guide hole formed on an upper surface of the second unit.

FIG. 6 is a cross-sectional view of the automatic tool changer, showing a state in which a minute gap is formed between the joining surfaces of the first unit and the second unit.

FIG. 7 is a front view of the automatic tool changer before inserting a part into a hole.

FIG. 8 is a front view showing a state in which a second unit is inclined with respect to the first unit.

FIG. 9 is a front view showing a state in which the part is inserted into a hole.

FIG. 10 is a sectional view of an automatic tool changer according to another embodiment of the present invention.

11 is a view on arrow AA of FIG.

[Explanation of symbols]

 1 1st unit 2 2nd unit 3 Pulse motor 4 Locking mechanism 5 Hooking part G Small gap

Claims (3)

[Claims] 1. An automatic tool changer comprising a first unit having a drive mechanism and a locking mechanism and a second unit having a hooking portion, wherein the locking mechanism is hooked by displacement of an output portion of the drive mechanism. And a state in which the joint surfaces of the first and second units are in close contact with each other and a minute gap while maintaining the locked state by controlling the displacement amount of the output section. The first and second units are connected to each other only when a certain amount of force is applied to the second unit with a gap between the joint surfaces of the first and second units. An automatic tool changer characterized in that it is displaced in three dimensions with respect to the unit. 2. A first motor having a pulse motor and a locking mechanism.
An automatic tool changer comprising a unit and a second unit having a hooking portion, wherein a locking mechanism is locked to the hooking portion by rotation of an output shaft of the pulse motor, and the output is provided. While maintaining the locked state by controlling the rotation amount of the shaft, it is possible to achieve a state in which the joint surfaces of the first and second units are in close contact with each other and a state in which a minute gap is formed.・ The second unit should be displaced in the three-dimensional direction with respect to the first unit only when a certain amount of force is applied to the second unit side with a gap formed between the joint surfaces of the second unit. Automatic tool changer characterized by. 3. At least one of the joint surfaces of the first and second units is provided with elastic biasing means for pressing the joint surface of the other unit, and between the joint surfaces of the first and second units. 3. The displacement of the second unit in the three-dimensional direction with respect to the first unit in a state where a gap is formed is performed against the urging force of the elastic urging means. The automatic tool changer described.