JPH02121777A - Connector for automatic tool changer - Google Patents

Abstract

PURPOSE: To enlarge a combining force and to prevent defective operation by turning a cam, bring its engaging part into contact with an engaging pin and pressurizing them to combine both units. CONSTITUTION: When the cam 15 is turned toward the engaging pin 46 with a cylinder 17 in a state that contacting surfaces of both units 2, 3 are brought into contact, the engaging part 15a of the cam 15 is brought into contact with the engaging pin 46 in a part wherein a distance from a turning shaft is equal to a distance between the engaging pin 46 and the turning shaft. Further, when the cam 15 is turned, since the engaging pin 46 is pressurized with the engaging part 15a in a part wherein the distance from the turning shaft is larger than a distance between the engaging pin 46 and the turning shaft in a combining state, both units 2, 3 are combined and locked.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a coupling device for an automatic tool changer, and more specifically, a coupling device for an automatic tool changer, and more specifically, a coupling device for a first unit connected to an operating means such as a robot, and a coupling device for various tools. and at least one second unit to which the first unit is attached.
The present invention relates to a coupling device for an automatic tool changer configured to be releasably connected to a unit.

[Conventional technology]

The automatic tool changer with the above configuration uses a coupling device that connects the robot side unit and tool side unit in a separable manner, but the conventionally known coupling device is mainly of the configuration shown in Fig. 8. Met.

That is, a tapered hole (103) is formed in the side wall of a recess (102) provided in a unit (101) on the robot side, and a steel ball (104) is inserted into this tapered hole (103) so that its inner end is recessed (102). A steel ball holder (105) is provided on the outside of the steel ball (104) so as to be movable up and down. The steel ball holder (105) is constantly urged downward by a compression spring (107) provided in the upper chamber (106), and is urged downward from the boat (108) in the lower chamber (109).
) when compressed air is supplied to it, it moves upward.

When the steel ball holder (105) descends to the position shown in the figure, its inner end surface presses the steel ball (104) inward, creating a depression (
The inner end of the steel ball (104) protrudes from the side wall of the steel ball (102). When the steel ball holder (105) rises, the steel ball (104)
are moved outwards and do not protrude from the side walls of the recess (102).

The tool side unit (110) is provided with a substantially cylindrical engagement protrusion (111) at a position corresponding to the recess (102) of the robot side unit I-(101), and is formed near the tip of the engagement protrusion (111). The steel ball (104) is inserted into the notch (112)
) is inserted and engaged.

Note that (113) is an O-ring for sealing.

When combining and integrating both units (101) and (110), first connect the chamber (109) below the unit (108).
) to raise the steel ball holder (105) and move the steel balls (104) outward, the robot side unit (101) and tool side unit (110
) are brought into contact with each other, and the tool side unit (11
0) on the robot side unit (10).
1) into the recess (102). Next, the lower chamber (
When the compressed air is discharged from the steel ball retainer (109),
5) is lowered and the steel ball (104) is pushed inward and engages with the notch (112) of the engagement protrusion (111). In this way, the coupling and integration of both units (101) and (110) is completed.

[Problem to be solved by the invention]

In the conventional coupling device, the steel ball (104) and the engagement protrusion (
Both units (101) (11
0), so when a large tool weighing about 100 kg is attached, such as a spot welding unit, the contact point between the engagement protrusion (111) and the steel ball (104), or the steel ball A very large contact pressure is generated at the contact point between the presser foot (105) and the steel ball (104).

For this reason, the contact part is depressed, and a steel ball (104) is placed in the depression.
is stuck and malfunctions, especially both units (101) (
110) has the disadvantage that the problem of inability to separate them is likely to occur.

This invention was made in view of the above circumstances, and its purpose is to provide a tool that has a very large locking force and that can be operated by attaching a tool that weighs several hundred kilograms. Another object of the present invention is to provide a coupling device for an automatic tool changer that is free from malfunction.

[Means for Solving the Problem] In order to achieve this object, the present invention takes the following technical means.

That is, the unit (2) is provided in one of the two units (2) and (3) so that it rotates around a rotation axis and the distance from the rotation axis gradually changes. A cam (1) having an engaging portion (15a) formed in
5), a cylinder (17) for driving the cam (15), and both units (2) provided in the other unit (3).
) With the contact surfaces of (3) in contact with each other, the cam (
The engaging portion (15a) of the cam (15) is provided with an engaging pin (46) that can be engaged with the engaging portion (15a) of the cam (15), and the engaging portion (15a) of the cam (15) is at a distance from the rotation axis of both units. )(2) The cam includes a portion equal to the distance between the engagement pin (46) and the rotation shaft when the contact surfaces in (3) are in contact with each other, and a portion larger than the distance. (15) and its engaging portion (15a)
By contacting and pressing the engaging pin (46),
It is characterized in that both units (2) and (3) are configured to be combined.

The cam (15) may be formed from a substantially fan-shaped plate, and the engaging portion (15a) may be provided at an arcuate edge thereof.

Further, the position of the rotation axis of the cam is such that at least a portion of the force in the direction of separating the two units (2) and (3) in the coupled state is caused by the engagement pin (4) by the cam (15).
It is preferable to set the pressure point 6) at a position that acts in a direction that increases the pressing force.

[Effect]

Since it is configured as above, both units (2) (
When the cam (15) is rotated toward the engagement pin (46) by the cylinder (17) with the contact surfaces of 3) in contact, the engagement portion (15a) of the cam (15) rotates. The engagement pin (46) is contacted at a portion whose distance from the moving axis is equal to the distance between the engagement pin (46) and the rotation axis.

When the cam (15) is further rotated, the engaging portion (15a)
In order to press the engagement pin (46) in a portion where the distance from the rotation axis is greater than the distance between the engagement pin (46) and the rotation axis in the coupled state, both units 1- (2) (3) can be combined and locked.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The figure shows an embodiment of an automatic tool changer using a coupling device according to the present invention.

In Fig. 7, (1) is an automatic tool changer, (2) is a first unit attached to an operating means (not shown) such as a robot 7) arm, and (3) is a spot welding gun (4). The attached second unit is shown. A plurality of second units (3) each having various tools such as the spot welding gun (4) attached thereto are prepared and arranged on a shelf. During work, any one second unit (
3) and combine/integrate it with the first unit (2),
A predetermined work can be performed by operating means such as a robot.

The upper first unit (2) has a main body part (2a) and a convex part (
2b), as shown in Part 3 and Figure 4,
The main body portion (2a) has a substantially Y-shaped shape formed by cutting out two substantially fan-shaped portions from a flat cylindrical member. Interface modules (5) and (6) are removably attached to the notches of the main body (2a), respectively, so that the entire body has a substantially single cylindrical shape. In addition, in the sector-shaped part (7) which is not cut out, there is an electric conduit (8) that sends a control electric signal to the tool attached to the second unit (3) on the side.
The tool is equipped with multiple air ports (9) for supplying and discharging control air, and an electrical conduit (9) is installed on the bottom surface.
8) and a joint (not shown) communicating with the air port (9). A flange (
10), and the interface modules (5) and (6) are bolted to this collar (10).

The convex portion (2b) is formed in a star shape and protrudes from the lower surface of the main body portion (2a). The convex portions (2b) are 12
It consists of three parts (11) extending along three radii 0'' and joined to each other in the center.

The inside of the first unit (2) has a convex portion (2
b) Each part (11) of the convex part (2b) is cut out in a star shape similar to the convex part (2b) at a depth reaching near the lower end.
Three cylinder housing chambers (12) are formed along the cylinder. This cylinder housing chamber (12) is a space that houses an air cylinder for driving a cam, which will be described later. The upper opening of the cylinder housing chamber (12) is closed by an IF (13) consisting of a circular plate attached to the upper surface of the main body (2a).

A rectangular hole is formed at the tip (lla) of each portion (11) of the convex portion (2b), and a window (14) is provided inside the window (14). A cam (15) is provided.

This cam (15) is located at the tip (lla) of the portion (11).
The support pin (16) passed through the window (14) from the outside in the horizontal direction (horizontal direction) allows the rack to be opened in a plane (vertical plane) parallel to the central axis of the first unit (2). It is pivotably supported and is pivotable between the exterior and interior of the portion (11) through the window (14).

A portion (15) where the cam (15) engages with an engagement pin (described later).
a) is an arcuate edge portion. For this reason, the support pin (
16) is provided near the corner (15b) of the cam (15) on the opposite side from the engaging portion (15a). Further, the distance between the engaging portion (15a) of the cam (15) and the rotation shaft, that is, the support pin (16) is minimum at the outer portion,
In order to set the support pin (16) so that it gradually increases toward the inside, the position of the support pin (16) is set at the arc-shaped engagement portion (15a).
It is set by shifting the angle between both ends of the line downward from the straight line that divides it into three equal parts.

The three cams (15) are connected to driving air cylinders (17) provided in the three cylinder housing chambers (12) mentioned above.
Each is driven by Each cylinder (17) is supported by a mounting base (19) fixed to the inner side surface of the portion (11) via a support member (18).
It is rotatable up and down along the central axis of the unit (2). Air is supplied to and discharged from the driving air cylinder (17) through an air port (
20) From (21), it is carried out via the connecting pipes (22) and (23).

The air cylinders (17) each have a piston rod (
24) is arranged parallel to the cam (15). A U-shaped joint (25) is fixed to the tip of the piston rod (24) with its two legs facing the cam (15). In a shape that is sandwiched between the two legs of
It is rotatably connected to the cam (15). Joint (
25) and the cam (15) are connected by a connecting pin (26) provided through both. Connection pin (
26) is a cam (15) at a position close to the engaging portion (15a).
) is passed through.

With the above configuration, when the driving air cylinder (17) is operated to move the piston rod (24) in and out, the movement is caused by the movement between the U-shaped joint (25) and the connecting pin (26).
is transmitted to the cam (15) by the cylinder (1
7) allows the cam (15) to rotate around the support pin (16).

The interface module (5) supplies welding current to the welding gun (4), and has an electrical conduit (27) on the side and an electrical contact (28a) on the bottom.
(28b) are provided respectively. Other modules (
6) supplies cooling water to the welding gun (4), and has a water port (29) on the side and a connection hole (30) on the bottom.
) are provided for each.

Note that (31) is a positioning bin provided on the lower surface of the main body (2a).

The second unit (3) has a substantially Y-shape similar to the first unit (2). The two roughly fan-shaped notches each contain an interface module (3
2) (33) is removably installed,
As a whole, it has a single cylindrical shape that is almost the same as the first unit (2). These modules (32)
(33) is paired with modules (5) and (6) which are attached to the first unit (2), and both units (2)
(3) are arranged so that they overlap each other when stacked.

The module (32) that supplies welding current has an electrical conduit (34) on the side and an electrical contact (35a) on the top.
35b), and the module (33) for supplying cooling water has a water port (36) on the side and a joint (37) on the top. Module (3
The electrical contacts (35a) (35b) of 2) are the electrical contacts (28a) (35b) of the module (5) of the first unit (2).
28b), and when both modules (32) and (5) overlap, they are connected. The two joints (37) of the module (33) are also connected to the connecting holes (30
) is provided at a position corresponding to In addition, both modules (
32 and 33, like the first unit (2), are bolted to a flange (38) provided at the edge on the notch side.

The fan-shaped part (39) of the second unit (3) has a space between the first unit (2) when both units (2) and (3) are stacked together.
an electrical connector (40) and a plurality of fittings (41) connected to electrical connectors and fittings (not shown), respectively;
is provided. This electrical connector (40) and fitting (4
1) are connected to an electrical conduit (42) and an air port (43) provided on the side of the fan-shaped portion (39), respectively.

The center part of the second unit (3) is cut out in a figure 7 shape, forming a space (44) that opens upward and downward. This space (
44) has a 7-shaped convex portion (
2b) is fitted. At the three outer ends of the space (44),
A recess (45) recessed radially outward is formed in each case,
This recess (45) is provided with an engagement pin (46) that extends horizontally from the outside of the second unit (3). As shown in FIG. 6, this engagement pin (46) is provided at a position close to the upper end of the second unit (3),
It is perpendicular to the plane containing the central axis of the second unit (3). When both units (2) and (3) are stacked, the space (
The outer surface of the tip (11a) of the convex portion (2b) of the first unit (2) is in contact with the inner wall surface (47) of each outer end of the first unit (2),
The outer end of the cam (15) fits into the recess (45). The lower opening of the space (44) is closed by a lid (48) made of a circular plate attached to the lower end of the second unit (3). The spot welding gun (4) is attached to this lid (4).
8).

In addition, (49) is a positioning hole into which the positioning pin (31) of the first unit (2) is inserted, and (50) (5
1) is the air port (20) of the first unit (2)
This is a joint connected to (21).

Next, the usage state of the automatic tool changer (1) configured as above will be explained.

Here, we will consider a case where the second unit (3) to which the illustrated spot welding gun (4) is attached is selected from among a plurality of second units (3) arranged in ranks with various tools attached to them. .

First, the first unit (2) attached to the robot arm
above the second unit (3), and align the two positioning pins (31) of the first unit (2) with the two positioning holes (49) of the second unit (3), respectively. and stop.

Next, lower the first unit (2) and attach the positioning pin (
31) into the positioning hole (49) of the second unit (3), and when both units (2) and (3) are stacked, the convex part (2b) of the first unit (2) will align with the second unit (2). Fits into the space (44) of the unit (3). At this time, the cam (
15) Air is supplied to each drive air cylinder (17) in the direction of retracting the piston loft (24), so as shown in Figure 1, most of the cam (15) is in the cylinder housing chamber. (12), so there is no problem in fitting both units (2) and (3) together.

When the lower end surface of the main body (2a) of the first unit (2) and the upper end surface of the second unit (3) are in complete contact, the
An electrical connector (not shown) and an air joint (not shown) provided on the fan-shaped portion (7) of the first unit (2) are connected to an electrical connector (40) and an air joint (not shown) provided on the fan-shaped portion (39) of the second unit (3). 41) respectively. Also, the electrical contacts (2) of the modules (5) (6) of the first unit (2)
8a) (28b) and the air connection hole (30) are also connected to the module (32) (33) of the second unit (3).
electrical contacts (35a) (35b) and air fitting (37)
), respectively.

In this way, electrical signals and air signals for control, welding current and cooling water sent from the robot to the first unit (2) are transmitted to the spot welding gun (4) via the second unit (3). It becomes possible to do so.

When both units (2) and (3) come into contact as described above, each air cylinder (
17) in the opposite direction, and the piston rods (24) are synchronously projected.

Then, the three cams (15) connected to each piston rod (24) rotate outward about the support pin (16), and as shown in FIG. The mating portion (15a) contacts the engagement pin (46) of the second unit (3).

As mentioned above, the distance between the engaging portion (15a) of the cam (15) and the support pin (16) is minimum at a position close to the engaging pin (46), and increases as the distance from the engaging pin (46) increases. Since the rotation angle increases gradually, the force pressing the engagement pin (46) increases as the rotation angle increases. thus,
The combination of both units (2) and (3) can be locked and held.

In this embodiment, the relative positions of the engagement pin (46) and the support pin (16) and the dimensions of the cam (15) are set appropriately when the units (2) and (3) are coupled, and the cam (
The position where the engaging part (15a) of 15) presses the engaging pin (46) and stops is determined from the center position where the bisector of the central angle of the cam (15) intersects the engaging part (15a). is set on the inside, so if a force acts in the direction of separating both units (2) and (3), the moment due to that force will mostly act in the direction of rotating the cam (15) outward. do. Therefore, since the force acts in a direction that strengthens the locking force of both units (2) and (3), there is an advantage that it is very difficult to separate the units (2) and (3) even in such a case.

In addition, in consideration of the case where the air supply is stopped due to an accident such as a power outage, a spring is built into the cylinder (17) so that the piston rod (24) will remain protruding even if the air runs out during connection. It is preferable to configure it so that it is retained.

When separating the combined units (2) and (3),
Air may be supplied to the cylinder (17) in the opposite direction to the above. In this way, the cam (15) rotates in the opposite direction and separates from the engagement pin (46), so that it can be easily separated.

In the above embodiment, the cam (15) is formed from a substantially fan-shaped plate, but the present invention is not limited to this, and can be implemented in various shapes such as a disk shape and a cylindrical shape. Of course. Furthermore, the engaging portion (15a) is not limited to a convex shape. The point is that the engaging portion of the cam includes a portion whose distance from the rotation axis is equal to the distance between the engagement pin and the rotation axis of the cam at the time of coupling, and a portion that is larger than the distance. It is sufficient if the distance changes gradually.

〔Effect of the invention〕

This invention has the configuration described above, and the cam (15) is connected to the engagement pin (46) via the engagement portion (15a).
), a bonding force is generated between both units (2) and (3), so that the steel ball (104) and the engagement protrusion (11
1) Compared to conventional devices that lock by engaging with
The contact pressure generated at the engaging part is small, and the cam (15)
and the engagement pin (46) may get caught during engagement and do not separate (
Therefore, even if a tool weighing several hundred kilograms is attached and operated, there is no risk of malfunction.

Further, the engagement portion (15a) of the cam (15) is connected to the engagement pin (
46) is pressed and stopped at a position inside the center position where the bisector of the central angle of the cam (15) intersects the engaging portion (15a), so that both the cams in the coupled state A position where, when a force in the direction of separation is applied to unit) (2) and (3), at least a part of the force acts in a direction to increase the pressing force of the engagement pin (46) by the cam (15). When set to , when the above force is applied, both units (2
) The locking force of (3) is strengthened, which has the effect that both units (2) and (3) will not separate even if a large force is suddenly applied.

[Brief explanation of the drawing]

The figure shows an embodiment of the coupling device for an automatic tool changer according to the present invention. In FIG. FIG. 2 is a partially cross-sectional explanatory diagram showing a state immediately before being combined. FIG. 2 is a partially sectional explanatory view showing a state in which both units are coupled and locked by the coupling device. FIG. 3 is a plan view of the first unit using the same coupling device. FIG. 4 is a partial cross-sectional explanatory diagram taken along line A-A in FIG. 3. FIG. 5 is a plan view of a second unit using the same coupling device. FIG. 6 is a partial cross-sectional explanatory diagram taken along line BB in FIG. 5. FIG. 7 is a perspective view of the automatic exchange device using the two units shown in FIGS. 3 to 6, with the units separated from each other. FIG. 8 is a partially sectional explanatory diagram showing an example of a conventional coupling device. (1)... Automatic tool changer (2)... First unit 7) (2a)... Main body (2b)...
Convex portion (3)...Second unit (4)...Spot welding gun

Claims (1)

[Claims] 1. A first unit (
2) and at least one second unit (3) to which various tools can be attached;
3) is separably connected to the first unit (2); 2), a cam (15) having an engaging portion (15a) that rotates around a rotation axis and that is formed so that the distance from the rotation axis gradually changes; (15) and both units (2) provided in the other unit (3).
The contact surfaces of the cams (15 and 3) are in contact with each other.
) can be engaged with the engaging portion (15a) of the engaging pin (4).
6), wherein the engaging portion (15a) of the cam (15) is at a distance from the rotation axis to the engaging pin when the contact surfaces of both the units (2) and (3) are in contact with each other. (46) and the rotation axis, and a portion that is larger than the distance, and rotates the cam (15) to engage the engaging portion (15a).
By contacting and pressing the engaging pin (46),
A coupling device characterized in that it is configured to couple both units (2) and (3). 2. The coupling device according to claim 1, wherein the cam (15) is made of a substantially fan-shaped plate, and the engaging portion (15a) thereof is provided on an arcuate edge. 3. The position of the rotation axis of the cam (15) is such that at least a portion of the force in the direction of separating the units (2) and (3) in the coupled state is caused by the engaging pin caused by the cam (15). The coupling device according to claim 1 or 2, wherein the coupling device is set at a position so as to act in a direction to increase the pressing force of (46).