JPH05169383A - Falling preventive device of automatic tool changing coupler - Google Patents

Abstract

PURPOSE:To make a unit so as not to fall out of another unit even if there is a malfunction due to misoperation and electrical noise and suchlike, in an automatic tool changing coupler consisting of the unit attached to a robot output part, via a floating mechanism and the tool side unit. CONSTITUTION:A falling preventive device is provided in addition to a coupler setting device. An engaged shaft 92 being free of fitting in an engaging part 19 (hole) of a unit 1 is engaged with a cam part 99 (groove hole) of a lifter 90 installed in another unit 2 by the small shaft 98. This lifter 90 has a shaft part 91 and it is always energized downward by dint of a tension spring 94. Even if the unit 1 and the unit 2 are going to a state of being separated by means of the coupler setting device, the engaged shaft 92 is left engaged intact, and when a robot goes down and the unit 2 is mounted on a tool rest 4, the shaft 91 is pushed up against the tension spring and engagement of the engaged shaft is released by operation of the cam part 99.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool change coupler including a first unit attached to an output section for a robot, and a second unit on the work side having a tool connected to the first unit. In particular, even if the pneumatic control system malfunctions due to an operator's erroneous operation, lightning, or other electrical noise, the automatic tool change coupler does not fall off from the robot arm inadvertently. It is about.

[0002]

2. Description of the Related Art In the above-mentioned automatic tool changing coupler, a first unit is usually provided with a return cylinder and a locking member, and an output shaft of the return cylinder associated with air supply to the return cylinder is provided. By moving the locking member by extension and contraction, and by connecting and disconnecting the moved locking member and the second unit portion, the second unit is connected to and disconnected from the first unit. There is.

That is, when air is supplied to the connection port side of the two ports sandwiching the piston in the return cylinder, the locking member is moved so as to be engaged with the second unit. The second unit can be connected to one unit, and conversely, when air is supplied to the disconnecting port side of the return cylinder, the locking member is moved to be disengaged from the second unit. The second unit can be separated from the first unit.

However, in the above-mentioned automatic tool change coupler, when the pneumatic control system malfunctions and air is supplied to the disconnecting port of the cylinder due to an operator's erroneous operation, lightning, or other electrical noise, the robot arm moves to the first position. Two
An accident occurs in which the unit drops out.

[0005]

Therefore, according to the present invention, the second unit can be easily connected to the first unit.
An automatic tool that does not hinder disconnection and that prevents the second unit from accidentally falling off from the robot arm even if the pneumatic control system malfunctions due to operator error, lightning, or other electrical noise. An object of the present invention is to provide a mechanism for preventing the replacement coupler from falling off.

[0006]

According to a first aspect of the present invention, there is provided a first unit attached to an output portion of a robot,
A drop-out prevention mechanism attached to an automatic tool change coupler, which comprises a tool-side second unit that is in a connected state with the first unit and is placed on a mounting table at the time of disconnection, which is one of the first and second units. The locking shaft is attached to one side so as to be movable back and forth and the other side of the first and second units is engaged and disengaged with one end of the locking shaft as the locking shaft moves back and forth. Below the lower surface of one of the engaging portion, the spring that biases the one end of the engaging shaft in the engaging state with the engaging portion, the cam portion, and the first and second units. When the second unit, which has an elevating body that has a shaft portion that protrudes to and is vertically movable, is placed at an appropriate position on the mounting table and is pushed in by the second unit that is in a connected state with the first unit. The cam mechanism pair of the lifting cam and the locking shaft. One end portion of the locking shaft is adapted to retract in order to disengaged from the engaging portion against the biasing force of the spring.

According to a second aspect of the present invention, there is provided an automatic system comprising a first unit attached to the output part of the robot and a second unit on the tool side which is in the connected state with the first unit and is placed on the table when the robot is separated. A locking mechanism attached to a tool exchange coupler, the locking shaft being mounted on one of the first and second units so as to be able to move back and forth inward and outward, and with this locking shaft moving forward and backward. The engaging portion provided on the other of the first and second units that is in a disengaged state with the one end portion, and the one end portion of the locking shaft is urged in a direction in which the engaging portion is in the locking state. When the second unit, which is composed of a spring and a cam table fixedly arranged on the table, is placed in an appropriate position on the table, the cam floor of the cam table and the locking shaft of the cam table are fixed. The locking shaft is formed by a cam-mechanical pair with the input section. One end is adapted to retract in order to disengaged from the engaging portion against the biasing force of the spring.

According to a third aspect of the present invention, there is provided an automatic system comprising a first unit attached to the output part of the robot and a second unit on the tool side which is in a connected state with the first unit and is placed on a table when the robot is separated. A fall prevention mechanism attached to a tool exchange coupler, the lever being attached to one of the first and second units so as to be swingable inward and outward, and a locking claw provided at an end of the lever. Then, the engagement claw that has moved along with the swing of the lever is in a disengaged state,
An engaging portion provided on the other of the first and second units, a spring that biases the locking claw in a direction in which the locking claw can be locked with the engaging portion, and a connection state with the first unit. When a certain second unit is placed at an appropriate position on the mounting table, it comprises a pressing member that disengages the locking claw from the engaging portion and swings the lever until the two are in a state where they cannot lock each other. I am trying.

[0009]

The present invention operates as follows. (Operation of the invention according to claim 1) When the coupler for automatic tool change is equipped with this drop-out prevention mechanism, the output is made in a state in which the second unit is connected to the first unit attached to the output part of the robot. When the unit is operating (when the second unit is not placed at the proper position on the table)
In addition, even if the pneumatic control system malfunctions due to operator error, lightning, or other electrical noise,
Since one end of the locking shaft provided in one of the second units is in a locked state with the engaging portion provided in the other of the first and second units, the second unit is Do not accidentally drop from one unit.

When the second unit, which is connected to the first unit, is placed at the proper position on the stand, the shaft portion is pushed in to act as a cam mechanism between the cam portion of the elevating body and the locking shaft. As a result of the pair, the locking shaft retracts and the locking between the one end of the locking shaft and the engaging portion is released, and as a result, like the conventional automatic tool changer, the first unit is moved to the first unit. Two
The unit can be detached. (Operation of the invention according to claim 2) When the coupler for automatic tool change is equipped with this drop-out prevention mechanism, even if the above-mentioned erroneous operation and erroneous operation occur, it is provided in one of the first and second units. Since the one end of the stop shaft is in a locked state with the engaging portion provided on the other of the first and second units, the second unit does not drop out of the first unit carelessly.

When the second unit connected to the first unit is placed at the proper position on the stand, the locking shaft is formed by a cam mechanism pair between the cam floor of the cam base and the input portion of the locking shaft. Is retracted and the engagement between the one end of the engagement shaft and the engagement portion is released, and as a result, the second unit can be separated from the first unit as in the conventional automatic tool changer. Becomes (Operation of the invention according to claim 3) When the coupler for automatic tool change is provided with this drop-out preventing mechanism, even if the above-mentioned erroneous operation and erroneous operation occur, the lever attached to one of the first and second units Since the locking claw is locked with the engaging portion provided on the other of the first and second units, the second unit does not accidentally drop from the first unit. When the second unit, which is in the connected state with the first unit, is placed at the proper position on the stand, the lever releases the locking between the locking claw and the engaging portion of the lever (unlockable). ), The second unit can be separated from the first unit as in the conventional automatic tool changer.

That is, when the conventional automatic tool change coupler is equipped with the drop-out prevention mechanism according to any one of the first to third aspects of the present invention, the connection and disconnection of the second unit with respect to the first unit is prevented easily. Furthermore, even if the pneumatic control system malfunctions due to an operator's erroneous operation, lightning, or other electrical noise, the second unit will not accidentally drop out of the robot arm.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings shown as embodiments. (Embodiment 1--Embodiment of the invention described in claim 1) As shown in FIG. 1, the automatic tool change coupler of the present invention is a tool-side second unit 2 mounted on a mounting table 4. And a first unit 1 attached to the arm A of the robot via a so-called floating device F. As shown in FIG. 2, the first unit 1 projects from the mating surface with the second unit 2. The second unit 2 has a concave portion 21 corresponding to the projecting portion 11, and the projecting portion 11 is fitted in the concave portion 21, so that the first unit 1 and the second unit 2 are provided. And are connected. As shown in FIG. 2, a return cylinder 3 and a locking tool 5 are provided on the side of the recess which is the inner surface side of the protrusion 11, and the return cylinder 3 is provided.
The locking device 5 is moved by the expansion and contraction of the output shaft 32 accompanying the supply of air to the disconnecting port 30 or the connection port 31, and the locking device 5 and the second unit 2 that have been moved are moved.
The second unit 2 is connected / disconnected from / to the first unit 1 by engaging / disengaging the portion. In order to prevent the second unit 2 from being accidentally dropped from the first unit 1, as shown in FIG. 1, a drop prevention mechanism D is provided.

As shown in FIG. 2 and FIG.
The first unit 1 is composed of a fan-shaped cam swingably supported by the first unit 1, and can be retracted from a pair of openings 10 formed in the first unit 1. The return cylinder 3 is, as shown in FIG.
The cylinder body 3 has a compression spring 33 on its side.
A shaft 36 is provided at the rear end of the shaft 5. Then, the end of the output shaft 32 and the end of the shaft 36 are attached to the above-mentioned locking tool 5 via pins, respectively, and the locking tool 5 of the first unit 1 is extended and contracted by the extension and contraction of the output shaft 32. It appears to emerge from the opening 10.

Further, as shown in FIG. 2, pins 20 are provided in the second unit 2 portion corresponding to the opening 10, respectively. As shown by the solid line in FIG.
When it is in a state of protruding from the above, the pin 20 and the pin 20 are engaged with each other and the second unit 2 is held in a proper state with respect to the first unit 1, and conversely, it is shown by a chain double-dashed line in FIG. As described above, when the locking tool 5 is in the retracted state, the engagement between the locking tool 5 and the pin 20 is released, and the second unit 2 can be separated from the first unit 1.

As shown in FIG. 4, the drop-out prevention mechanism D described above has a hole 19 (corresponding to the engaging portion in the column of means) provided in the side wall of the projecting portion 11 of the first unit 1 and the second unit. 2, a vacant chamber 22 formed therein, an elevating body 90 having inner and outer surfaces formed into an open rectangular tube shape and capable of moving up and down in the vacant chamber 22, and a tension spring for urging the elevating body 90 downward. 94, a shaft portion 91 projecting from the lower portion of the elevating body 90 and protruding through the lower surface of the second unit 2 when the elevating body 90 is located in the lower part of the vertical movement range, and the elevating body 9
The recessed portion 2 is provided so as to be able to advance and retreat inward and outward in a manner of being inserted into the inner and outer surfaces of 0, and the inner end is inserted into the hole 19 (locked in the vertical direction) when in the inner position.
1, a locking shaft 92 that projects through the inside of the shaft 1, and a cam mechanism 93 that moves the locking shaft 92 forward and backward as the shaft 91 moves up and down. In this embodiment, the cam mechanism 93 is
As shown in FIG. 3 and FIG. 4, the small shaft 98 protruding backwardly at a right angle to the peripheral surface of the central portion of the locking shaft 92, and the lifting body 9
0 is formed on both side walls and has a slit-shaped cam portion 99 that is inclined upward toward the inside, and the small shaft 98 is inserted into the cam portion 99.

Since this embodiment is constructed as described above, the arm A operates while the second unit 2 is connected to the first unit 1 attached to the arm A of the robot. Even if the pneumatic control system malfunctions (when the second unit 2 is not mounted at the proper position of the mounting table 4) due to an operator's erroneous operation, lightning, or other electrical noise, as shown in FIG. , Locking shaft 92
Due to the engagement of the inner end of the second unit 2 with the hole 19 provided in the side wall of the protruding portion 11 of the first unit 1, the second unit 2 does not accidentally drop from the first unit 1.

When the second unit 2 connected to the first unit 1 is placed in the fourth position, the shaft portion 91 is pushed in as shown in FIG. 5, and along with this, the cam mechanism 93 is pushed. The locking shaft 92 moves outward via the lock shaft 92 to release the locked state between the inner end of the locking shaft 92 and the hole 19, and as a result, the second unit 2 can be separated from the first unit 1. ..

That is, according to this embodiment, like the conventional automatic tool changer, the second unit can be easily connected / disconnected from the first unit, and is further attached to the arm of the robot. When the arm A is operating with the second unit 2 connected to the first unit,
Even if the pneumatic control system malfunctions due to an operator's erroneous operation, lightning, or other electrical noise, the second unit 2 will not accidentally drop out of the robot arm.

In the above embodiment, the engaging portion in the column of the means is the hole 19, but the invention is not limited to this, and the groove 18 may be opened downward as shown in FIG. (Embodiment 2 ... Embodiment of the invention described in claim 2) In this embodiment, the basic structure of the first unit 1, the second unit 2 and the like is substantially the same as that of the first embodiment. However, the fall prevention mechanism D has the following configuration.

That is, as shown in FIGS. 7 and 8, the drop-out prevention mechanism D is attached to the outer peripheral side of the first unit 1 and hangs down toward the second unit 2;
It is mounted so that it can move back and forth to 0, and is urged in the forward direction by the compression spring 84. In the forward state, the inner end is located below the second unit 2, and in the backward state, the inner end is the second unit 2. Locking shaft 81 located away from below
And a cam table 40 fixedly arranged on the stand 4. In this embodiment, the outer peripheral surface of the lower surface of the second unit 2 is the engaging portion described in the column of means.

As shown in the figure, the outer end of the locking shaft 81 is composed of an L-shaped bracket 82 and a roller 83 rotatably attached to the bracket 82. On the other hand, the cam base 40, as shown in FIG.
The cross-section is formed into a substantially right-angled triangular shape, and the slope portion serves as a cam floor 41. Then, when the second unit 2 connected to the first unit 1 is placed at the proper position of the placing table 4, as shown in FIG.
3 is rolled to be guided to the cam floor 41 of the cam base 40 (corresponding to the cam mechanism pair described in the column of means), and as a result, the locking shaft 81 resists the biasing force of the spring and is in the retracted state. I am trying to be.

Therefore, when the second unit 2 in the connected state with the first unit 1 is placed at the proper position of the stand 4 as described in the section of the operation of the invention according to claim 2 (see FIG. 9). Since the second unit 2 can be separated, the second unit 2 is prevented from being accidentally detached from the robot arm due to an erroneous operation and an erroneous operation. still,
In this embodiment, the engaging portion in the section of the means is the outer peripheral portion of the lower surface of the second unit 2, but it is not limited to this, and it may be a hole or a protruding piece provided in the side wall of the second unit 2. (Embodiment 3 ... Embodiment of the invention described in claim 3) In this embodiment, the basic structure of the first unit 1, the second unit 2 and the like is substantially the same as that of the first embodiment. However, the fall prevention mechanism D has the following configuration.

That is, the fall prevention mechanism D is shown in FIGS.
As shown in FIG. 1, a lever 6 formed in a substantially L shape having a vertical piece and a horizontal piece and provided on the outer peripheral side of the second unit 2.
0, a support 61 for attaching the lever 60 to the second unit 2 so that the swing fulcrum of the lever 60 is near the bent portion thereof, and a support body provided at the upper end of the lever 60 and transverse to the vertical piece. The locking claw 62 extending in the same direction as the piece, the engaging portion 63 provided in the first unit 1, and the lever 6
A push rod 64 (corresponding to the pressing member in the column of means) which extends downwardly from the lower end of the second unit 2 and extends toward the engaging portion 63. The lever 6 to the position where they can be engaged with each other.
And a spring 65 for rocking 0. Then, as shown in FIG. 12, when the second unit 2 connected to the first unit 1 is placed at an appropriate position of the mounting table 4, the lower end portion of the push rod 64 and the mounting surface of the mounting table 4 are placed. With the contact with the lock claw 62, the locking claw 62 of the lever 60 moves to a position where it cannot engage with the engaging portion 63 against the urging force of the spring 65.

As shown in FIGS. 11 and 12, the support 61 is composed of a flange 61a stretched over the lower outer periphery of the second unit 2 and a bracket 61b projecting from the upper surface of the flange 61a. A hole 61c for loosely inserting the push rod 64 is formed in the flange 61a portion between the outer peripheral surface of the second unit 2 and the bracket 61b.

As shown in the figure, a compression coil spring is adopted as the spring 65, and the spring 65 is interposed between the projecting projecting piece 29 stretched on the outer peripheral surface of the second unit 2 and the upper part of the lateral piece of the lever 60. There is. A so-called kick spring may be adopted as the spring 65, and in this case, it is provided between the lever 60 and the bracket 61b. Alternatively, a leaf spring may be adopted.

As shown in FIG. 11, the push rod 64 is swingable by being attached to a lateral piece of the lever 60 via a shaft. The engaging portion 63, as shown in FIG.
It is a shaft and is supported by a bracket protruding from the outer peripheral surface of the first unit 1. The engagement portion 63 is not limited to the above-described aspect, and may be, for example, the first unit 1
The hole may be provided in the second unit 2, and in this case, the locking claw 62 and the lower wall of the hole lock the second unit 2 from the first unit 1.

Therefore, when the second unit 2 in the connected state with the first unit 1 is placed at the proper position of the stand 4 as described in the section of the action of the invention according to claim 3 (see FIG. 12). Since the second unit 2 can be separated, the second unit 2 is prevented from being accidentally detached from the robot arm due to an erroneous operation and an erroneous operation.
Although the push rod 64 is attached to the lateral piece of the lever 60 in the above embodiment, the present invention is not limited to this, and the push rod 64 may be arranged on the table 4 side as shown in FIG. Good. (Embodiment 4 ... Embodiment of the invention described in claim 3) In this embodiment, the basic structure of the first unit 1, the second unit 2 and the like is substantially the same as that of the above-mentioned embodiment 1. However, the fall prevention mechanism D has the following configuration.

That is, the fall prevention mechanism D is shown in FIGS.
5, a concave portion 77 (corresponding to the engaging portion described in the column of means) provided on the outer peripheral surface of the second unit 2,
A lever 70 attached to the outer peripheral side of the first unit 1 so as to swing inward and outward, and having a swing lower end portion as a locking pawl 76;
A spring 71 for urging the locking claw 76 toward the inner position.
And the second unit 2 to the first unit on the inner surface side of the swing lower end.
Consists of a cam floor 72 that is provided so as to incline inward toward the unit 1, and a pressing tool 73 (corresponding to the pressing member in the column of means) that is fixedly arranged on the mounting table 4 and has a rotatable roller 74. Has been done. When the lower swing end of the lever 70 is in the inner position, the locking claw 76 and the wall surface forming the recess 77 are in the engaged state, and when the lower swing end of the lever 70 is in the outer position, the lock is locked. Nail 7
6 and the wall surface forming the recess 77 are disengaged, and when the second unit 2 connected to the first unit 1 is placed at the proper position of the mounting table 4, As shown in FIG. 16, the locking claw 76 of the lever 70 is moved to the outer side position against the biasing force of the spring 71 by a cam mechanism pair of the cam floor 72 and the roller 74 of the pressing tool 73. is there.

Therefore, the same effect as that of all the above-mentioned embodiments can be obtained. In this embodiment, the engaging portion is the concave portion 77, but the engaging portion is not limited to this and may be, for example, a protruding piece.

[0031]

The present invention having the above-mentioned structure has the following effects. The invention according to claims 1 to 3 does not hinder the easy connection and disconnection of the second unit with respect to the first unit, and further controls the air pressure by an operator's erroneous operation, thunder, or other electrical noise. Even if the system malfunctions, the second unit will not accidentally drop off from the robot arm.

That is, the connection and disconnection of the second unit 2 with respect to the first unit 1 is not hindered, and even if the pneumatic control system malfunctions due to an operator's erroneous operation, lightning, or other electrical noise. Thus, it is possible to provide a mechanism for preventing the automatic tool change coupler from falling off, which prevents the second unit from accidentally falling off from the robot arm.

[Brief description of drawings]

FIG. 1 shows an automatic tool change coupler of a first embodiment equipped with a fall prevention mechanism of the present invention attached to a robot arm, and a stand for mounting a second unit of the automatic tool change coupler. FIG.

FIG. 2 is an explanatory view of a first unit and a second unit in the automatic tool changing coupler.

FIG. 3 is a perspective view of a first unit and a second unit in the automatic tool changing coupler.

FIG. 4 is a view showing a mutual relationship between parts such as a locking shaft and a shaft portion in a state where the automatic tool changing coupler is not placed on a mounting table.

FIG. 5 is a view showing a mutual relation of parts such as a locking shaft and a shaft portion in a state where the automatic tool changing coupler is mounted on a mounting table.

FIG. 6 is a view showing another mode of an engaging portion in the automatic tool changing coupler.

FIG. 7 is a stand for mounting the automatic tool change coupler of the second embodiment equipped with the dropout prevention mechanism of the present invention attached to the robot arm, and the second unit of the automatic tool change coupler. FIG.

FIG. 8 is a diagram showing the relationship between the second unit and the locking shaft in a state where the automatic tool change coupler of the second embodiment is not placed on the stand.

FIG. 9 is a view showing the relationship between the second unit and the locking shaft in a state where the automatic tool changing coupler of the second embodiment is placed on the table.

FIG. 10 shows an automatic tool exchanging coupler according to a third embodiment equipped with a dropout prevention mechanism of the present invention attached to an arm of a robot, and a stand for mounting a second unit of the automatic tool exchanging coupler. FIG.

FIG. 11 is a diagram showing the relationship between the locking claws of the lever and the engaging portion in a state where the automatic tool changing coupler of the third embodiment is not placed on the stand.

FIG. 12 is a view showing a relationship between a locking claw of a lever and an engaging portion in a state where an automatic tool changing coupler according to a third embodiment is placed on a stand.

FIG. 13 is a view showing another embodiment of the push rod in the automatic tool changing coupler.

FIG. 14 is an automatic tool change coupler of a fourth embodiment equipped with a dropout prevention mechanism of the present invention attached to an arm of a robot, and a stand for mounting a second unit of the automatic tool change coupler. FIG.

FIG. 15 is a view showing the relationship between the locking claws and the recesses when the automatic tool change coupler of the fourth embodiment is not placed on the stand.

FIG. 16 is a view showing the relationship between the locking claws and the concave portions when the automatic tool changing coupler of the fourth embodiment is placed on the placing table.

[Explanation of symbols]

 1 1st unit 2 2nd unit 3 Return cylinder 4 Stand 6 Normally closed valve 7 Normally closed valve 19 Engagement part 30 Separation port 31 Connection port 40 Cam stand 60 Lever 62 Locking claw 63 Engagement part 64 Push rod 70 Lever 73 Pressing Tool 76 Engaging Claw 77 Recess 81 Engaging Shaft 84 Compression Spring 90 Elevating Body 91 Shaft Part 92 Engaging Shaft 94 Tension Spring 99 Cam Part

Front page continued (72) Inventor Toichi Oue 172 Itazawa-cho, Yamatokoriyama-shi, Nara Nitta Stock Company Nara Factory (72) Inventor Kiyotaka Inoue 172 Ikezawa-cho, Yamatokoriyama City Nara Stock Nara Factory (72) Inventor Chiichi Chiyo 172 Ikezawa-cho, Yamato-Koriyama City, Nara Nitta Co., Ltd.Nara Factory (72) Inventor Katsumi Higuchi 172 Ikezawa-cho, Yamato-Koriyama City, Nara Nitta Co., Ltd. (72) Inventor Masafumi Yamamoto Yamato-Koriyama, Nara Prefecture 172 Ikezawa-machi, Ichi Nitta Stock Company Nara factory

Claims (3)

[Claims] 1. An automatic tool change coupler comprising a first unit attached to the output part of a robot and a second unit on the tool side which is connected to the first unit and is placed on a placing table when detached. And a locking shaft attached to one of the first and second units so as to be movable back and forth in an inward / outward direction, and an engagement / disengagement state with one end of the locking shaft as the locking shaft moves back and forth. The first and second
The engaging portion provided on the other of the units, the spring for urging the one end portion of the locking shaft in the direction in which the one end portion is locked with the engaging portion, the cam portion, and the first and second units. A second unit, which is connected to the first unit and is in a connected state, is mounted at an appropriate position on the mounting table. When the shaft portion is pushed in by the lever, one end portion of the locking shaft is disengaged from the engaging portion against the biasing force of the spring by the cam mechanism pair of the cam portion of the lifting body and the locking shaft. A mechanism to prevent the coupler from falling off for automatic tool change, which is designed to move backward. 2. An automatic tool exchanging coupler comprising a first unit attached to the output part of a robot and a second unit on the tool side which is connected to the first unit and is placed on a placing table when detached. And a locking shaft attached to one of the first and second units so as to be movable back and forth in an inward / outward direction, and an engagement / disengagement state with one end of the locking shaft as the locking shaft moves back and forth. The first and second
From the engaging portion provided on the other of the units, the spring for urging the one end of the locking shaft in the direction in which the one end of the locking shaft is locked with the engaging portion, and the cam table fixedly arranged on the mounting table. Consists, first
When the second unit in the connected state with the unit is placed at the proper position of the stand, one end portion of the locking shaft is caused by a cam mechanism pair between the cam floor of the cam table and the input portion of the locking shaft. A fall prevention mechanism for an automatic tool change coupler, characterized in that it is retracted so as to be disengaged from an engaging portion against the biasing force of a spring. 3. An automatic tool exchanging coupler comprising a first unit attached to the output part of the robot and a second unit on the tool side which is connected to the first unit and is placed on a placing table when detached. And a locking claw provided at an end of the lever, the lever being attached to one of the first and second units so as to be swingable inward and outward. An engaging portion provided on the other of the first and second units, which is in a disengaged state with the engaging pawl that has moved in accordance with the movement, and a state in which the engaging pawl can engage with the engaging portion. When the second unit that is connected to the first unit and the second unit that is connected to the first unit are placed at the proper positions on the mounting table, the locking claws are disengaged from the engaging portions, and the two cannot lock each other. From the pressing member that swings the lever until A mechanism to prevent the coupler from falling off for automatic tool change.