JP3453635B2 - Automatic tool changer - Google Patents

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 including a first unit and a second unit which is detachably connected to the first unit.

[0002]

2. Description of the Related Art An automatic tool changer of this type has already been disclosed in Japanese Patent Application No. 63-269293. As shown in FIG. 7, this automatic tool changer includes a tool-side second unit 2 mounted on a mounting table D when the tool is separated.
And the first unit 1 attached to the arm A of the robot
The second unit 2 is connected / disconnected to / from the first unit 1 as shown in FIGS. 7 and 8.
Air is supplied to the connecting / disconnecting ports 30 and 31 of the cylinder 3 provided on the unit 1 side to extend / shorten the output shaft 32 of the cylinder 3 so that the cam 4 is normally / reversely rotated. It is carried out.

The cam 4 is, as shown in FIGS. 7 and 8,
It is rotatably attached to the side of the first unit 1 by the rotating shaft 39, and the engaging portion 40 has a distance from the rotating shaft 39 as shown in FIG. Contact point P between the engagement pin 20 and the cam 4 between the units 1 and 2
There is a larger portion 42 and a smaller portion 41 with a portion equal to the distance a from the rotating shaft 39 to the rotating shaft 39 as a boundary.

Therefore, when the cam 4 is rotated in the direction in which the cam 4 is projected to the outside, on the way of the rotation, that is, the engaging portion 40.
When the contact point P of slightly exceeds the engagement pin 20, the cam 4 and the engagement pin 20 are in a strong engagement state. However, for example, as shown in FIG. 9, when the foreign matter D is caught between the engagement portion 40 of the cam 4 and the engagement pin 20 and the engagement is incomplete, a large external force is applied to the second unit 2 side. As shown in FIG. 10, when the shock is applied, the engagement is disengaged, and the second unit 2 falls off the first unit 1, resulting in an accident.

[0005]

SUMMARY OF THE INVENTION In view of the above, according to the present invention, an automatic tool in which the second unit does not inadvertently drop off from the first unit even when the engagement of the cam serving as the coupling device and the engagement pin is incomplete. An object is to provide a switching device.

[0006]

According to the present invention, a cam 4 having an engaging portion 40 is rotatably attached to one of the first and second units 1 and 2 and an engaging pin is attached to the other unit. An automatic tool changer that includes 20 and connects and disconnects the first and second units 1 and 2 by contact / non-contact between the engaging portion 40 and the engaging pin 20 accompanying the forward / reverse rotation of the cam 4. In the device, the distance from the rotation center of the cam in the engaging portion 40 is the first and second in the connected state.
Between the contact point P and the center of rotation of the unit 1 and 2, the part equal to the distance a from the contact point P of the engagement pin 20 and the cam 4 to the center of rotation and the contact point P as a boundary. Large-diameter portion 4 whose distance from the center of rotation is greater than the distance a between
2 and a small small-diameter portion 41, the small-diameter portion 41 is provided with an engaging projection 5, and the distance from the center of rotation to the tip of the engaging projection 5 is between the contact point P and the center of rotation. Distance a
It is set smaller than.

In the above invention, the engaging projection 5 is
It is preferable to have a linear portion 50 whose distance from the center of rotation increases gradually from the large diameter portion 42 toward the small diameter portion 41.

[0008]

The present invention operates as follows. When the engagement between the engagement portion 40 of the cam 4 and the engagement pin 20 is incomplete, a large external force (a force that separates the second unit 2 from the first unit 1) is applied to the second unit 2 side. When it is shocked, the engagement protrusion 5 and the engagement pin 20 are brought into an engaged state, so that the second unit 2 does not accidentally fall off from the first unit 1.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings shown as embodiments. As shown in FIG. 1, the automatic tool changing device of this embodiment comprises a tool-side second unit 2 mounted on a mounting table D and a first unit 1 attached to an arm A of a robot. As shown in FIGS. 1 and 2, the first unit 1 is configured such that the protrusion 11 protruding from the joint surface of the first unit 1 with the second unit 2 is fitted into the recess 21 of the second unit 2. And the second unit 2 are connected.

As shown in FIG. 2, a reciprocating cylinder 3 and a cam 4 are provided in the recess 12 on the inner surface side of the above-mentioned protrusion 11, and the connecting / disconnecting port 30, 30 for the cylinder 3 is provided. By supplying air to 31, the output shaft 32 is expanded / contracted to rotate the cam 4 about the rotation shaft 39. As shown in FIG. 3, the cam 4 is composed of a substantially fan-shaped thick plate, and its R-shaped portion is an engaging portion 40 with an engaging pin 20 described later. As shown by the chain line, it is possible to project and retract from the opening 10 formed in the first unit 1. Further, as shown in FIG. 3, the engaging portion 40 has a contact point between the engaging pin 20 and the cam 4 in the first and second units 1 and 2 which are in the connected state when the distance from the rotating shaft 39 is large. There is a large-diameter portion 42 and a small-diameter portion 41 that are larger than the portion equal to the distance a from P to the rotating shaft 39, and the small-diameter portion 41 has a portion from the rotating shaft 39 to the end. The engaging protrusion 5 is provided so that the distance b to the portion is smaller than the distance a.

As shown in FIG. 4, the engagement projection 5 of this embodiment has a linear portion 50 whose distance from the rotation shaft 39 gradually increases from the large diameter portion 42 toward the small diameter portion 41. As shown in FIG. 4, when the engaging portion 40 and the engaging pin 20 are in the incompletely engaged state, in the direction X orthogonal to the separating direction Y of the first and second units 1 and 2, The distance c from the rotating shaft 39 to the tip of the engaging projection 5 is set to be larger than the distance d from the rotating shaft 39 to the engaging pin 20.

As shown in FIG. 2, the cylinder 3 has a compression spring 33 on the side of the connection port 31 described above, and a shaft 36 is provided at the rear end of the cylinder body 35.
Then, the end portion of the output shaft 32 and the end portion of the shaft 36 are attached to the cam 4 via pins, respectively, so that the extension and contraction of the output shaft 32 allows the cam 4 to be retracted from the opening 10 of the first unit 1. I am doing it.

Further, as shown in FIG. 2 and FIG. 3, pins 2 are respectively provided in the second unit 2 portions corresponding to the openings 10.
0 is provided, and as shown by the solid line in FIG.
0 and the second unit 2 is held in an appropriate state with respect to the first unit 1, and conversely, as shown by the chain double-dashed line in FIG. 1 and FIG. At a certain time, the engagement between the pin 20 and the pin 20 is released so that the second unit 2 can be separated from the first unit 1.

In the automatic tool changer of this embodiment, the engaging portion 40 of the cam 4 is provided with the engaging projection 5 as described above. Therefore, as shown in FIG. When the foreign matter D is caught in the engaging pin 20 and the engagement is incomplete, when a large external force is shocked to the second unit 2 side, the second unit 2 moves from the first unit 1 Although it separates slightly to fall off, as shown in Fig. 6,
The linear portion 50 of the engaging projection 5 and the engaging pin 20 are in an engaged state (in this state, the outer peripheral surface of the engaging pin 20 is composed of the curved surface portion of the engaging portion 40 and the linear portion 50). Since the two units are in contact with each other), the second unit 2 does not accidentally drop off from the first unit 1.

In the above embodiment, the angle between the end edge 43 of the cam 4 and the linear portion 50 is not particularly limited, and the shape of the protrusion is not limited to the triangular shape.

[0016]

The present invention having the above-mentioned structure has the following effects. From the contents described in the action column,
It was possible to provide an automatic tool changer in which the second unit does not accidentally fall off from the first unit even if the engagement of the cam serving as the coupling device and the engagement pin is incomplete.

[Brief description of drawings]

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

FIG. 2 is a sectional view of the automatic tool changer.

FIG. 3 is a view showing a state in which an engagement portion of a cam and an engagement pin are in an engaged state or a disengaged state in the automatic tool changing device.

FIG. 4 is a diagram showing a relationship between a cam and an engagement pin in an incompletely coupled state.

FIG. 5 is a view showing a state in which the first and second units are connected to each other with a foreign substance interposed between the engagement portion of the cam and the engagement pin.

FIG. 6 is a view showing a state in which an engagement protrusion and an engagement pin provided on the cam are in an engaged state.

FIG. 7 is a cross-sectional view of a prior art automatic tool changer.

FIG. 8 is a view showing a state in which an engagement portion of a cam and an engagement pin are in an engaged state or a disengaged state in the automatic tool changer of the prior art.

FIG. 9 is a view showing a state where a foreign matter is present between an engaging portion of a cam and an engaging pin in the automatic tool changer of the prior art.
A diagram showing a state in which the second units are connected to each other.

FIG. 10 is a view showing a state in which the engagement portion of the cam and the engagement pin are disengaged and the second unit is falling off from the first unit in the automatic tool changer of the prior art.

[Explanation of symbols]

a distance b distance P contact point 1st unit 2 Second unit 4 cams 5 engagement protrusion 40 Engagement part 41 parts 42 parts 50 straight part

Claims (2)

(57) [Claims] 1. Out of the first and second units (1) and (2),
Cam (4) with engaging portion (40) on one unit
Is rotatably mounted and the other unit is provided with an engagement pin (20), and the engagement portion (40) and the engagement pin (20) are brought into contact with each other when the cam (4) is rotated in the forward and reverse directions.・ Connecting the first and second units (1) and (2) to each other without contact
In the automatic tool changer that separates and separates, the distance from the rotation center of the cam in the engagement portion (40) to the engagement pin (20) between the first and second units (1) and (2) in the connected state. A portion equal to the distance (a) from the contact point (P) with the cam (4) to the rotation center and the contact point (P) as a boundary between the contact point (P) and the rotation center. The large diameter part (4
2) and a small diameter portion (41), the small diameter portion (4
1) The engaging protrusion (5) is provided, and the distance from the center of rotation to the tip of the engaging protrusion (5) is greater than the distance (a) between the contact point (P) and the center of rotation. An automatic tool changer characterized by being set small. 2. The engagement protrusion (5) has a linear portion (50) whose distance from the center of rotation increases gradually from the large diameter portion (42) toward the small diameter portion (41). The automatic tool changer according to claim 1.