JP2015231658A - Automatic tool changer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic tool changer which has a simple structure corresponding to a low load capacity, and of which a cost of manufacture can be reduced and a dimension can be so suppressed as to be small.SOLUTION: A first unit 400 has a piston 450 and two cam mechanisms 460, and a second unit 500 has two lock pins 510 corresponding to said two cam mechanisms 460 respectively. The piston 450 has a head member 450a, a lower piston 450b and an upper piston 480 which is oscillatively connected to the lower piston 450b. Two recesses 480c of the upper piston 480 are moved by advancement and retraction of the head member 450a, whereby the cam mechanism 460 engaging with each recess 480c is rotated, and each cam mechanism 460 becomes an engagement state or an engagement release state with respect to respective corresponding lock pins 510.

Description

  The present invention relates to an automatic tool changer applied to various industrial robots.

  As an automatic tool changer (Auto Tool Changer) applied to various industrial robots, a first unit connected to operation means of the robot and at least one second unit to which various tools are attached are provided. What connected the unit to the 1st unit so that attachment or detachment is possible is known. In the apparatus, the first unit has a driving mechanism and a locking mechanism, and the second unit has a locking portion corresponding to the locking mechanism. The locking mechanism is driven by the drive mechanism, and the locking mechanism is brought into a locked state or a locked release state with respect to the locking portion. When one locking mechanism is driven by one driving mechanism, the number of driving mechanisms corresponding to the number of locking mechanisms is required to drive a plurality of locking mechanisms. The automatic tool changer having the number of drive mechanisms corresponding to the number of the locking mechanisms has a problem that the size is increased by the number of drive mechanisms.

  In order to solve the above problem, the applicant of the present application has proposed an automatic tool changer capable of driving three or more locking mechanisms with one driving mechanism, as shown in Patent Document 1, for example. However, the automatic tool changer disclosed in Patent Document 1 has a configuration suitable for a high-medium load robot, and has a high-strength and complex structure that can withstand a large load applied during use, resulting in high manufacturing costs and large dimensions. There is a problem. An automatic tool changer applied to a low-load robot needs a simple structure corresponding to a low loadable weight.

  Here, an example of an automatic tool changer capable of driving three or more locking mechanisms with one drive mechanism as described above will be described with reference to FIG. The automatic tool changer 601 according to the example has a configuration suitable for a high-medium load robot, and a first unit in which a protrusion 640 is formed on one end surface 604a and an operation unit such as a robot arm is attached to the other end surface 604b. 604 and a second unit 605 having a hole 650 into which a projection 640 can be inserted while attaching various tools such as a welding tool to one end surface 605a. The first unit 604 and the second unit 605 are in contact with the cam mechanism (locking mechanism) 646 and the lock pin (locking portion) 651 (that is, the cam mechanism 646 is locked with the lock pin 651). Are connected to each other.

  The first unit 604 includes a cylinder portion 644, a piston (drive mechanism) 645, a pair of elastic members 648, and a cam mechanism (locking mechanism) 646. The second unit 605 has a lock pin (locking portion) 651 corresponding to the cam mechanism 646 in the hole 650. The piston 645 includes a piston output portion 647 provided with a recess that engages with the cam mechanism 646. The cam mechanism 646 is driven by the piston 645 so that the cam mechanism 646 is locked or unlocked with respect to the corresponding lock pin 651.

  The connecting operation between the first unit 604 and the second unit 605 is as follows. First, as shown to Fig.4 (a), the position of each outer peripheral part of the 1st unit 604 and the 2nd unit 605 is match | combined mutually. At this time, air is supplied from a robot arm (not shown) to the cylinder unit 644. Then, the piston 645 moves in the direction 610 of the white arrow in FIG. Further, along with this movement, the pair of elastic members 648 are urged (compressed) in the direction 610.

  Next, in FIG. 4B, air for connecting the first unit 604 and the second unit 605 is inserted into the space on the elastic member 648 side of the cylinder portion 644 with the protrusion 640 inserted into the hole 650. Supplied. As a result, when the internal pressure in the space increases, a restoring force in a direction opposite to the direction 610 of the white arrow in FIG. 4A is generated in each elastic member 648 functioning as a safety mechanism. The piston 645 moves in the opposite direction according to the internal pressure of the space and the restoring force of each elastic member 648. Along with this movement, the cam mechanism 646 rotates counterclockwise in FIG. 4B (in the direction 620 of the thick arrow) and comes into contact with the lock pin 651 so that the lock mechanism 650 is locked. Become. As a result, the cam mechanism 646 is restricted from moving in the direction opposite to the insertion direction of the protrusion 640 into the hole 650, and the connection between the first unit 604 and the second unit 605 is completed.

  In the automatic tool changer 601, three or more cam mechanisms 646 can be rotated by advancing and retracting one piston 645. Further, an annular sliding body 649 capable of sliding with respect to the boundary circumferential surface is provided on the boundary circumferential surface on the terminal end side of the recess in the piston output portion 647. Even when the cam mechanism 646 and the lock pin 651 have a processing error due to sliding with respect to the boundary circumferential surface of the annular slide body 649, or when the cam mechanism 646 and the lock pin 651 are worn during use of the device 601, the cam An even contact / locking state between the mechanism 646 and the lock pin 651 can be ensured.

Japanese Patent No. 3177814 JP 2012-250327 A

  The automatic tool changer 601 in FIG. 4 has a high strength and complicated structure that can withstand a large load applied during use, and thus has a problem of high manufacturing costs and large dimensions.

  An object of the present invention is to provide an automatic tool changer that has a simple structure corresponding to a low loadable weight, can reduce manufacturing costs, and can keep dimensions small.

  An automatic tool changer according to the present invention includes a first unit having a drive mechanism and a plurality of locking mechanisms, and a second unit having a plurality of locking portions corresponding to each of the plurality of locking mechanisms, When the protrusions provided in the first unit are inserted into the holes provided in the second unit, the plurality of locking mechanisms in the protrusions are locked to the corresponding locking parts, respectively. Thus, the automatic unit is an automatic tool changer in which the first unit and the second unit are coupled to each other, and the drive mechanism includes a head member, and a lower output unit connected to the head member. An upper output unit coupled to the lower output unit so as to be swingable, and an upper output unit provided with a plurality of recesses for engaging with each of the plurality of locking mechanisms, The plurality of head members are moved forward and backward When the portion moves, the plurality of locking mechanisms rotate, and the plurality of locking mechanisms are locked or unlocked with respect to the corresponding locking portions, respectively. To do.

  According to the present invention, it has a simple structure corresponding to a low loadable weight, can reduce the manufacturing cost, and can keep the size small.

It is a sectional side view showing the state before the 1st unit and the 2nd unit which constitute the automatic tool changer concerning one embodiment of the present invention are connected. (A) is a sectional side view showing a state before driving each cam mechanism for connection between the first unit and the second unit, and (b) is a connection between the first unit and the second unit. It is a sectional side view which shows the state made. It is a figure which shows operation | movement of a piston and each cam mechanism when a 1st unit and a 2nd unit are connected. It is a figure which shows the connection operation | movement of the 1st unit and 2nd unit which comprise the conventional automatic tool changer, Comprising: (a) is the side which shows the state before a 1st unit and a 2nd unit are connected. It is sectional drawing, (b) is a sectional side view which shows the state with which the 1st unit and the 2nd unit were connected.

  Hereinafter, an embodiment for carrying out the present invention will be described.

  As shown in FIG. 1, an automatic tool changer 100 according to an embodiment of the present invention is attached between a robot arm (not shown) and a tool (not shown), and the robot arm is attached to the other end surface 400b. Has a first unit 400 which can be attached and detached, and a second unit 500 which can attach and detach a tool to one end surface 500a. The first unit 400 and the second unit 500 can be connected to each other.

  The robot arm can supply and exhaust air with the first unit 400. The piston (driving mechanism) 450 generates a driving force for rotating two cam mechanisms 460 described later according to the supply / exhaust. A plurality of tools to which the second unit 500 is attached in advance are prepared and arranged on the shelf. And among each 2nd unit 500 to which the tool was attached, one 2nd unit 500 is selected according to work, and the selected 2nd unit 500 and the 1st unit 400 are connected so that attachment or detachment is possible. The robot arm can be made to perform a predetermined work.

  A connector for connecting paths of electricity, air, oil, water, and the like is provided on the joint surface between the first unit 400 and the second unit 500. In order to properly connect the connector, the first unit 400 and the second unit 500 need to be positioned. For this reason, the second unit 500 has two positioning holes 560 (only one is shown in FIG. 1), and the first unit 400 is inserted into each of the two positioning holes 560. Positioning pins 410 (only one is shown in FIG. 1).

(Configuration of the first unit 400)
As shown in FIG. 1, the first unit 400 has an outer peripheral portion 400c formed in a substantially cylindrical shape, and has a protruding portion 440 protruding from the central portion of the one end surface 400a opposite to the other end surface 400b. The protrusion 440 is formed in a bowl-shaped substantially cylindrical shape.

  The first unit 400 includes a cylinder lid 420, a cylinder part 430, a piston (drive mechanism) 450 accommodated in the cylinder part 430, and two cam mechanisms that can protrude from the inside of the protruding part 440 to the outside of the protruding part 440 ( (Locking mechanism) 460 and ports 405a and 405b for supplying or discharging air between the robot arm and the cylinder part 430. A part of each cam mechanism 460 is accommodated in a concave accommodation space 440 a formed in the protrusion 440, and a part of the piston 450 is a substantially cylindrical accommodation space 440 b formed in the protrusion 440. Is housed in.

  The piston 450 includes a head member 450a, a lower piston (lower output portion) 450b connected to the head member 450a, and an upper piston (upper output portion) 480 that is swingably connected to the lower piston 450b.

  The lower piston 450b is integrated with the head member 450a by a fastening member 465 such as a nut. The lower piston 450 b is disposed in the cylindrical sliding member 455 and slides with respect to the inner peripheral surface of the sliding member 455. The lower piston 450b has one enlarged diameter portion 470a at the other end (connected to the upper piston 480) opposite to the one end connected to the head member 450a.

  The upper piston 480 is coaxial with the lower piston 450b and is connected to the lower piston 450b by a connecting pin 475 so as to be swingable. The upper piston 480 has a start end side widened portion 480a, a terminal end side widened portion 480b, and two concave portions 480c. A start-side widened portion 480a is formed at the start end of the upper piston 480 (the end close to the head member 450a and the lower piston 450b), and the end of the upper piston 480 (the end on the side far from the head member 450a and the lower piston 450b). Portion) is formed with a terminal widening portion 480b, and two concave portions 480c are formed between the start end portion and the end end portion of the upper piston 480. The start-side widened portion 480a, the terminal-side widened portion 480b, and the two concave portions 480c are provided at a constant interval from the start-end portion toward the terminal portion. The cross section of each recess 480c is C-shaped.

  Each cam mechanism 460 includes a pointed portion 460a inserted into each concave portion 480c, an engaging portion 460b provided on the opposite side of the pointed portion 460a, and a straight line provided between the pointed portion 460a and the engaging portion 460b. Part 460c. The engaging portion 460b is configured by an arc surface, and the straight portion 460c is configured by a substantially flat surface. Each cam mechanism 460 is supported on the protrusion 440 by a support pin 490 extending in a direction perpendicular to the protrusion direction of the protrusion 440. Each cam mechanism 460 is rotatable about the support pin 490 in a state where the sharpened portion 460a is inserted into the recessed portion 480c (engaged state). The cam mechanism 460 is provided approximately every 180 ° in the circumferential direction of the first unit 400. The two cam mechanisms (upper and lower cam mechanisms shown in FIG. 1) 460 have the same configuration.

  As shown in FIG. 1, each port 405a, 405b is connected to a robot arm (not shown) via an air tube (not shown). Thereby, air can be supplied and exhausted between the robot arm and the first unit 400. The piston 450 is movable along the axial direction of the first unit 400 in response to supply of air to the ports 405a and 405b or discharge of air from the ports 405a and 405b. With this movement, the cam mechanisms 460 engaged with the respective recesses 480c rotate about the support pins 490, respectively.

(Configuration of second unit 500)
As shown in FIG. 1, the second unit 500 has an outer peripheral portion 500 b formed in a substantially cylindrical shape, like the outer peripheral portion 400 c of the first unit 400. A tool (not shown) is detachably attached to one end surface 500 a of the second unit 500.

  The second unit 500 includes a hole 550 into which the protrusion 440 can be inserted, two lock pins (locking portions) 510 corresponding to the two cam mechanisms 460, and a positioning hole 560 into which the positioning pin 410 can be inserted. Have. The hole 550 has substantially the same shape as the protrusion 440. The positioning hole 560 is formed at a position corresponding to the positioning pin 410.

(Connection operation of the first unit 400 and the second unit 500)
Hereinafter, the connecting operation of the first unit 400 and the second unit 500 will be described with reference to FIGS. 1 and 2.

  First, as shown in FIG. 1, the positions of the outer peripheral portions 400 c and 500 b of the first unit 400 and the second unit 500 are aligned with each other. At this time, air is supplied from the robot arm toward the cylinder portion 430 of the first unit 400 via the port 405a. The piston 450 moves in the direction away from the cylinder lid 420 (direction 200 of the white arrow in FIG. 1) by the pressure (driving force) accompanying the supply of air. With this movement, the lower cam mechanism 460 pivots clockwise in FIG. 1 (thick arrow 300) around the support pin 490, and the upper cam mechanism 460 centers around the support pin 490 in FIG. By rotating counterclockwise, the two cam mechanisms 460 are accommodated in the corresponding accommodating spaces 440a. At this time, the linear portion 460c is maintained in a state of being in contact with the enlarged diameter portion 470a and the start end side widened portion 480a.

  2A, the first unit 400 moves in the direction 200 shown in FIG. 1, so that the protrusion 440 is inserted into the hole 550, and the other end surface 500c of the second unit 500 on the first unit 400 side is The unit 400 is in contact with the one end surface 400 a of the unit 400. That is, FIG. 2A shows a state before each cam mechanism 460 is driven for connection.

  Thereafter, with the protrusion 440 inserted into the hole 550, air is discharged from the cylinder 430 toward the robot arm via the port 405a and from the robot arm toward the cylinder 430 via the port 405b. Air is supplied. The piston 450 moves in the direction of the black arrow (direction approaching the cylinder lid 420) 350 in FIG. 2B in accordance with the driving force accompanying the supply / exhaust of air.

  Along with this movement, in each cam mechanism 460, the contact state between the linear portion 460c and the start-side widened portion 480a is released. Further, the lower cam mechanism 460 rotates counterclockwise (in the direction indicated by the thick arrow 380) about the support pin 490 in FIG. 2B, and the upper cam mechanism 460 centers on the support pin 490 in FIG. By rotating clockwise in (b), the engaging portion 460b and the lock pin 510 abut. As a result, each cam mechanism 460 is engaged with the corresponding lock pin 510.

  This restricts the movement of each cam mechanism 460 in the direction opposite to the direction in which the protrusion 440 is inserted into the hole 550 (direction 200 in FIG. 1), and the other end surface 500c of the second unit 500 is the first unit. By contacting the one end surface 400 a of 400, the connection between the first unit 400 and the second unit 500 is completed.

(Operations of upper piston 480 and each cam mechanism 460 during connection)
FIG. 3 is a diagram illustrating operations of the upper piston 480 and the cam mechanisms 460 when the first unit 400 and the second unit 500 are coupled.

  As shown in FIG. 3, in each cam mechanism 460, the sharpened portion 460a engages with the start-side widened portion 480a (arranged in the concave portion 480c), and the linear portion 460c comes into contact with the enlarged diameter portion 470a. Thus, the unlocked state with respect to the lock pin 510 is maintained. At this time, the center line K40 of each cam mechanism 460 is substantially parallel to the center line K35 of the lower piston 450b.

  The upper piston 480 swings with respect to the lower piston 450b around the connecting pin 475. Here, the lower piston 450 b has a cut bottom surface (engagement mechanism) 470 b in a portion that supports the connecting pin 475. The swing angle range K30 of the upper piston 480 with respect to the lower piston 450b is regulated by the engagement between the cut bottom surface 470b and the corner portions 485a and 485b of the start-side widened portion 480a in the upper piston 480. Thereby, each cam mechanism 460 starts to rotate from the position of the unlocked state, and it is ensured that the pointed portion 460a contacts the end-side widened portion 480b. In addition, when each cam mechanism 460 is engaged with the corresponding lock pin 510, the upper piston 480 is centered on the connecting pin 475 so that the two cam mechanisms 460 come into contact with the corresponding lock pin 510 simultaneously. It swings with respect to the lower piston 450b.

  Next, a state when the automatic tool changer 100 is used will be described.

  According to the automatic tool changer 100, the upper piston 480 can swing with respect to the lower piston 450b about the connecting pin 475. That is, the upper piston 480 swings around the connecting pin 475 toward the accommodation space 440a.

  When each cam mechanism 460 comes into contact with the corresponding lock pin 510, the upper piston 480 can swing with respect to the lower piston 450b about the connecting pin 475. Therefore, even when there is a processing error in the cam mechanism 460 or the lock pin 510, or when the cam mechanism 460 or the lock pin 510 is worn during use of the apparatus 100, the cam mechanism 460 and the lock pin 510 are evenly distributed. A contact / locking state can be secured.

  Specifically, when a gap is generated between the locked cam mechanism 460 and the lock pin 510, the upper piston 480 is moved downward (in the direction from the upper piston 480 toward the lower piston 450b) by the action of the piston 450. The upper piston 480 can swing with respect to the lower piston 450b about the connecting pin 475 so that the gap is eliminated by the force to be displaced and the upper piston 480 cannot be displaced downward. .

  In other words, in this embodiment, the upper piston 480 swings with respect to the lower piston 450b to compensate for machining errors or wear of the cam mechanism 460 and the lock pin 510, and the cam mechanism 460 and the lock pin 510 are evenly distributed. A contact / locking state can be secured. That is, it is possible to compensate for processing errors and wear of the constituent members, and it is possible to maintain an appropriate connection state between the first unit 400 and the second unit 500 over a long period of time.

  As described above, according to the present embodiment, it has a simple structure corresponding to a low loadable weight, can reduce the manufacturing cost, and can keep the size small. The automatic tool changer 100 according to this embodiment has a configuration suitable for a low-load robot.

  Moreover, the recessed part 480c which each engages with each cam mechanism 460 is provided, and the upper piston 480 which is in direct contact with each cam mechanism 460 is not integral with the lower piston 450b but is a separate member from the lower piston 450b. It is connected to the lower piston 450b and can be separated from the lower piston 450b. For this reason, when the upper piston 480 needs to be replaced due to wear or the like, the upper piston 480 may be separated from the lower piston 450b and replaced, and the entire piston 450 need not be replaced. Therefore, the component cost of the automatic tool changer 100 can be reduced as compared with the case where the upper piston 480 is configured integrally with the lower piston 450b.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims.

In the above embodiment, the cam mechanism 460 is rotated by supplying and exhausting air between the robot arm and the first unit 400. However, liquid supply or The cam mechanism 460 may be rotated by discharging, or the cam mechanism 460 may be rotated by a drive mechanism using a motor, a solenoid, or the like.
In the above embodiment, the outer peripheral portion 400c of the first unit 400 and the outer peripheral portion 500b of the second unit 500 are substantially cylindrical, but the shape of each outer peripheral portion can be changed as appropriate.
-In above-mentioned embodiment, although the projection part 440 is a bowl-shaped substantially cylindrical shape, the shape of the projection part 440 can be changed suitably. Similarly, the shape of the hole 550 into which the protrusion 440 can be inserted may be appropriately changed according to the shape of the protrusion 440.

DESCRIPTION OF SYMBOLS 100 Automatic tool changer 400 1st unit 405a, 405b Port 410 Positioning pin 420 Cylinder lid 430 Cylinder part 440 Protrusion part 440a, 440b Storage space 450 Piston (drive mechanism)
450a Head member 450b Lower piston (lower output part)
455 Sliding member 460 Cam mechanism (locking mechanism)
460a Pointed portion 460b Engagement portion 460c Linear portion 465 Fastening member 470a Expanded diameter portion 470b Cut bottom surface (engagement mechanism)
475 Connecting pin 480 Upper piston (upper output part)
480a Starting end side widened portion 480b End side widened portion 480c Recessed portion 485a, 485b Corner portion 490 Support pin 500 Second unit 510 Lock pin (locking portion)
550 Hole 560 Positioning hole K30 Oscillation angle range K35, K40 Center line

Claims (8)

A first unit having a drive mechanism and a plurality of locking mechanisms;
A second unit having a plurality of locking portions corresponding to each of the plurality of locking mechanisms,
When the protrusions provided in the first unit are inserted into the holes provided in the second unit, the plurality of locking mechanisms in the protrusions are locked to the corresponding locking parts, respectively. By the automatic tool changer, the first unit and the second unit are connected to each other,
The drive mechanism includes a head member, a lower output unit connected to the head member, and an upper output unit coupled to the lower output unit so as to be swingable, and each of the plurality of locking mechanisms. And an upper output portion provided with a plurality of recesses to be engaged with,
When the plurality of recesses move as the head member advances and retracts, the plurality of locking mechanisms rotate, and the plurality of locking mechanisms lock or engage each of the corresponding locking portions. An automatic tool changer characterized by being in a stop release state.   The automatic tool changer according to claim 1, wherein the upper output unit is swingably connected to the lower output unit by a connection pin.   3. The automatic tool changer according to claim 1, wherein the plurality of concave portions are formed between a start end portion and a terminal end portion of the upper output portion.   The automatic tool changer according to any one of claims 1 to 3, wherein each of the plurality of locking mechanisms has a pointed portion inserted into the corresponding concave portion.   Each of the plurality of locking mechanisms includes the pointed portion and an engaging portion provided on the opposite side of the pointed portion and abutting against the corresponding locking portion, and the engaging portion corresponds to the corresponding The automatic tool changer according to claim 4, wherein the automatic tool changer is brought into a locked state with respect to the corresponding locking portion by contacting the locking portion.   When the head member and the lower output part move in a direction away from the cylinder lid of the first unit, the plurality of locking mechanisms are rotated, whereby the plurality of lockings are accommodated in the accommodating space of the protrusion. The automatic tool changer according to any one of claims 1 to 5, wherein the mechanism is accommodated.   The said lower output part has an enlarged diameter part which contacts with these locking mechanism in order to maintain these locking mechanisms in the said lock release state, The any one of Claims 1-6 characterized by the above-mentioned. An automatic tool changer according to claim 1.   The automatic tool changer according to any one of claims 1 to 7, wherein the lower output unit has an engagement mechanism that regulates a swing angle range of the upper output unit with respect to the lower output unit. .