JP2675434B2 - Hand exchange method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention includes first and second arms, and rotationally drives the first and second arms around first and second axes, respectively. In this assembly system, a hand detachably attached to the tip of the second arm is moved to a predetermined position to assemble parts, and the assembly work is executed while exchanging a plurality of types of hands. The present invention relates to a hand exchange method in an assembly system.

[Prior Art] Generally, when performing various assembly works with one robot having a rotary system, a plurality of hands are prepared according to the type of the assembly work, and an appropriate one is selected from these hands. Then, it is attached to the tip of the rotating arm. For this reason, it becomes necessary to replace the hand, and accordingly, a hand attaching / detaching device for attaching / detaching the hand to / from the arm tip of the robot is required. In addition, it is necessary to hold a plurality of waiting hands in advance and to remove and store the currently used hand, and this rack is formed with a concave portion for holding the plurality of hands. ing.

[Problems to be Solved by the Invention] However, in the conventional hand exchange method,
As shown in FIG. 11, the opening of each recess b of the rack a described above is formed to have a straight portion c, while
Since the hand is attached to the tip of the rotating arm,
The movement locus of the hand for inserting the hand into the corresponding concave portion b is inevitably a curve. That is,
In a robot having a rotary system, so-called PTP control is generally executed, and as long as such PTP control is executed, linear movement in the set movement between two points A and B is impossible. As indicated by the solid line α in the figure, the movement locus is inevitably a curve, and the curvature of the curve locus also differs depending on the load and the speed, and its prediction is difficult.

As a result, when attaching / removing the hand to / from this recess, the hand draws a curved locus, so the hand comes into contact with the part indicated by the symbol β in FIG. 11, and the hand cannot be attached / detached smoothly, Due to the abrasion, it becomes impossible to maintain the accurate position of the hand in the rack, and in the worst case, there is a problem that the robot cannot remove the hand.

Here, by using the well-known CP control, linear interpolation is possible even in a robot having a rotary system, and the hand can be moved along the linear direction indicated by the alternate long and short dash line γ in FIG. Points will be avoided.
However, in order to execute such CP control, CP
The high speed and high load of U are required, so that the cost of the electrical system including the CPU will increase significantly and new problems will occur.

The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to achieve smooth take-in and take-out of a hand into a rack in a state where an inexpensive PTP control is executed by a robot having a rotary system. It is to provide a possible hand exchange method.

[Means for Solving the Problem and Its Action] In order to solve the above-mentioned problems and achieve the object thereof, a hand exchanging method according to the present invention includes first and second arms. 2 arms for the first and second
An assembly system that moves the hand detachably attached to the tip of the second arm to a predetermined position by rotationally driving each of the axes around the axis of the In the hand replacement method in the assembly system for executing the assembly work while exchanging,
The distance between the first shaft and the hand attached to the tip of the second arm is set between the mounting part of the rack on which the hand is detached and placed and the first shaft. A first step of rotationally driving the second arm around a second axis so that the distance is the same as the second axis, a second step of fixing the second axis, and the first axis. And a third step of rotating the first arm around and attaching the hand at the tip of the second arm to the corresponding rack.

[Embodiment] An embodiment of a hand exchanging method according to the present invention will be described in detail below with reference to FIGS. 1 to 10D of the accompanying drawings, in the case of being applied to a scalar type robot.

<Description of Robot System> First, with reference to FIG. 1, a schematic configuration of a robot (automatic assembly device) 12 to which the hand exchanging method of this embodiment is applied will be described.

The robot 12 is attached to a column 14 fixed on a base (not shown), and is attached to the upper end of the column 14, and the central axis of the column 14 is the first rotation axis A ₁ and the first rotation axis A ₁ A first horizontal arm 16 rotatably supported around in a horizontal plane.
And a vertical axis attached to the tip of the first horizontal arm 16 and passing through the tip of the first horizontal arm 16
As A ₂ , a second horizontal arm 18 rotatably supported in the horizontal plane about the second rotation axis A ₂ , and vertical movement at the tip of the second horizontal arm 18 and movement about its own axis. The vertical arm 20 is rotatably supported and has a vertical arm 20 formed of a hollow cylindrical body. Here, at the lower end of the vertical arm 20, a hand attaching / detaching device 10 that detachably supports a hand to be described later is attached.

Then, the first horizontal arm 16 is set so as to be pivotally driven by the first drive motor 21 arranged in the column 14 about the first rotation axis A ₁ which is the central axis of the column 14. ing. In addition, the second horizontal arm 18 includes a second drive motor 22 disposed substantially in the center of the upper surface of the first horizontal arm 16.
Thus, the second horizontal axis A ₂ defined at the tip of the first horizontal arm 16 is pivotally driven. On the other hand, the vertical arm 20 includes the third and fourth drive motors 24, 2 arranged on the upper end of the second horizontal arm 18.
6 is set so as to move in the up-down direction (Z-axis direction) and be driven to rotate about its own central axis.

The first to fourth drive motors 21, 22, 24, 26 are connected to the robot via connection lines (not shown) arranged so as to pass through the columns 14 and the first horizontal arm 16. Based on the control command of the robot controller, connected to the controller 28, the hand mechanism 30 attached to the hand attaching / detaching device 10 is controlled to be rotationally driven so as to move to a predetermined position in a predetermined posture (rotational position). Has been done.

Further, the hand mechanism 30 is connected to a robot controller 28 and a pneumatic mechanism (not shown) via a connection cable 32, and is controlled so as to be driven via the robot controller 28 and the pneumatic mechanism. Here, this connecting cable 32 passes through the inside of the column 14 and passes through the first horizontal arm 16
Of the second horizontal arm 18 so as to cover the third and fourth drive motors 24 and 26 once in a state of penetrating through the base end of the second arm, once being taken out to the outside, and being bent so as to largely loop. After being connected to the cover member 27 arranged on the base end portion, it is taken out again from here and is taken in from the upper end of the vertical arm 20 in a state of being bent so as to largely loop. The hand mechanism 30 through the hand attaching / detaching device 10.
It is configured to be connected to.

Further, a hand exchange station 13 is provided on the above-mentioned base (not shown) in a state of being located within the access range of the hand attaching / detaching device 10. In the hand exchanging station 13, a horizontally extending mounting base 17 is fixed via a support post 15, and the mounting base 17 holds a plurality of hand mechanisms 30 in an independent state. A plurality of hand stands 96 are attached.
The configuration of the hand stand 96 will be described in detail later.

<Description of Hand Attachment / Detachment Device 10> Next, with reference to FIGS. 2 to 9, a hand attachment / detachment device
The ten configurations will be described in detail.

This hand attachment / detachment device 10 includes a vertical arm 20 of a robot 12.
A hand mechanism 30 is detachably attached to the lower end of the holder, and as shown in FIG. 2, a holder 34 fixed to the tip of the vertical arm 20 and a holder 34 that is detachable from the holder 34. The hand mechanism 30 basically includes a shank 36 fixed to the lower part.

Holder As shown in the figure, the holder 34 includes a fixing portion 37 fixed to the outer periphery of the lower end of the vertical arm 20, a cylinder portion 40 attached to the lower surface of the fixing portion 37 via a bolt 38, and the cylinder portion 40. Inside, a piston 42 slidably accommodated along the vertical direction, an inner cylinder 44 integrally fitted over the lower end surface and the lower inner circumference of the cylinder portion 40, and the inner cylinder 44
A ball support cylinder 48 fixed inside by a bolt 46, and a lower end of the piston 42 fixed by a bolt 50, and engaging from below from inside lower parts of a plurality of balls 52 supported by the ball support cylinder 48. A locking member 54 having an outer tapered surface 54a formed on the outer periphery, and a coil spring 56 interposed between the ball support cylinder 48 and the piston 42 for constantly urging the piston 42 upward. ing.

Here, the above-mentioned cylinder part 40 divides an inner space of the cylinder body 40a into an upper part and a lower part, as shown in FIG. A partition wall 40b (shown in FIG. 2),
It is integrally formed from a first outer flange portion 40c formed on the outer periphery of the upper end of the cylinder body 40a and a second outer flange portion 40d formed on the outer periphery of the lower end of the cylinder body 40a.

A wide slit 40e extending vertically along the center line is formed over the first outer flange portion 40c just above the partition wall 40b of the cylinder body 40a. Since the slit 40e is formed in this way, the connection cable 32 penetrating the inside of the vertical arm 20 is
As shown in FIG. 2, it can be taken out from the lower end opening of the vertical arm 20 into the internal space above the partition wall 40b of the cylinder part 40, and from there, it can be taken out to the outside of the cylinder part 40 via the slit 40e. It will be.

As shown in FIG. 2, the connection cable 32 includes a first air hose 32a for introducing compressed air into a cylinder chamber 58, which will be described later, and nine second air hoses for supplying compressed air to the hand mechanism 30. It is composed of an air hose 32b (only one is drawn for convenience of the drawing) and a cable 32c for electrically connecting the hand mechanism 30 and the robot controller 28. Then, the first air hose 32a is connected to the central portion of the partition wall 40b via the first connection port 60a.
The second air hose 32b of the book is connected to the upper surface of the second outer flange portion 40d via the second connection port 60b, respectively. Further, the cable 32c has the second outer flange portion 40d via the first connector 62a connected to the tip thereof.
The relay board 66 is electrically connected to the relay board 66 mounted above the stay 64.

On the other hand, the cylinder chamber 58 described above is defined by a space surrounded by the lower surface of the partition wall 40b, the upper surface of the piston 42, and the inner peripheral surface of the cylinder body 40a. Then, the piston 42 is configured such that the piston main body 42a that is in sliding contact with the inner peripheral surface of the cylinder main body 40a, and the central cylindrical portion of the lower surface of the piston main body 42a is set to project downward, and the solid cylindrical projecting portion 42b It is integrally formed.

Here, the piston 42 thus configured, in the state where compressed air is not introduced into the cylinder chamber 58,
The coil spring 56 is elastically held at the uppermost position in contact with a stopper (not shown) by the biasing force of the coil spring 56. Also,
The piston 42 is pushed downward against the biasing force of the coil spring 56 by introducing compressed air into the cylinder chamber 58 via the first connection port 60a, and the inner cylinder 44 described above is pressed. It comes to be held at the lowest position by contacting the upper end of the.

Further, the above-mentioned inner cylinder 44 is set so as to be fitted to the inner peripheral surface of the lower part of the cylinder body 40a, and the inner cylinder body 44a of a hollow substantially cylindrical shape opened at the top and bottom, and the upper end of this inner cylinder body 44a And an outer flange portion 44c formed at the lower end of the inner cylinder main body 44a and contacting the lower surface of the second outer flange portion 40d. Here, the lower surface of the outer flange portion 44c is set so as to define the upper side of the attachment / detachment surface PL. That is, the above-described shank 36 is defined in a portion below the lower surface of the outer flange portion 44c.

The above-mentioned ball support cylinder 48 is formed in a cylindrical shape with an open lower surface, and in detail, as shown in FIG. 4 taken out and shown, it is set so as to be fitted to the upper part of the inner cylinder body 44a. It is integrally formed of a hollow cylindrical support cylinder main body 48a and a ceiling portion 48b formed so as to cover the upper surface of the support cylinder main body 48a. Here, an insertion hole 48c is formed in the central portion of the ceiling portion 48b, through which the above-mentioned protruding portion 42b of the piston 42 is vertically movably inserted. Further, the thickness of the support cylinder body 48a is set to be thinner than the diameter of the ball 52 supported by the support cylinder body 48a.

Incidentally, the ball support cylinder 48, in a state of penetrating the support cylinder main body 48a in the thickness direction, a plurality of ball support cylinders 48 at equal intervals along the circumferential direction,
In this embodiment, six ball support holes 48d are formed at equal intervals along the circumferential direction. Then, each ball support hole 48d is set to a front circular shape having a diameter set slightly larger than the diameter of the ball 52 so that the ball 52 can be inserted and moved therein. ing. That is, each ball 52 has a corresponding ball support hole.
At least one side (inner side and / or outer side) is projected from 48d.

Here, in order to prevent the balls 52 from rolling outward in the radial direction from the corresponding ball support holes 48d, a locking sleeve 68 is fitted around the outer periphery of the support cylinder main body 48a. The locking sleeve 68 is fixed after the lower end thereof is positioned so as to extend slightly downward from the upper edge of each ball support hole 48d to form a locking claw. More specifically, a taper surface 68a is formed at the lower end of the locking sleeve 68 and extends downward in the radial direction. The taper surface 68a extends exactly above the corresponding ball support hole 48d. It is set to go out.
In this way, each ball 52 is set so as to be locked to the tapered surface 68a of the locking sleeve 68 and to be prevented from falling out from the corresponding ball support hole 48d in the radial direction.

As shown in FIG. 2 again, the above-mentioned locking member 54 is a substantially disk-shaped main body portion fixed to the lower end of the protruding portion 42b protruding into the internal space of the ball supporting cylinder 48 through the insertion hole 48c. Five
4b and the support cylinder body 4 formed at the lower end of the body portion 54a.
An outer flange portion 54 having an outer peripheral surface that slidably contacts the inner peripheral surface of 8a.
c. And this outer flange part 5
The above-described outer tapered surface 54a is defined between the upper edge of 4c and the lower edge of the main body portion 54b. The outer tapered surface 54a is inclined so that its diameter increases as it goes downward.

Also, with the inner peripheral surface of the support cylinder body 48a of the ball support cylinder 48,
The gap between the locking member 54 and the outer peripheral surface of the main body portion 54b is set to be large enough to prevent the balls 52 from coming out inward. In this way, these balls 52 are supported in the ball support holes 48d of the ball support cylinder 48 in a state in which they are prevented from slipping outward or inward.
In particular, the diameter of the outer peripheral surface of the main body portion 54b is such that when the ball 52 is biased radially inward as shown by the chain double-dashed line in FIG. Hole 48
Large enough to be fully retracted within d.

The outer tapered surface 54a abuts the inner portion of the corresponding ball 52 in a state where the piston 42 is lifted to the uppermost position, as shown by the alternate long and short dash line in FIG. In the state in which the outer portions of the pistons 42 are biased toward the outside so as to project outward from the outer peripheral surface of the support cylinder main body 48a, and the piston 42 is pushed down to the lowest position, two points are shown in FIG. As shown by the chain line, the engagement with the inner part of the corresponding ball 52 is released, and the balls 52 are allowed to move inward in the radial direction, and the outer parts of the balls 52 protrude from the outer peripheral surface of the support cylinder main body 48a. It is set not to.

That is, as shown in FIG. 5, when the piston 42 is lowered to the lowest position, the open state of the hand attaching / detaching device 10 is defined. Here, in order to detect the lowermost position of the piston 42, the opening 40f is formed in the middle of the cylinder body 40a of the cylinder portion 40 described above, and at a position facing the lower end of the piston body 42a at the lowest position. The lowermost position confirmation sensor 70 is attached to the cylinder body 40a via the stay 72 while being arranged in the opening 40f. This bottom position confirmation sensor 70
Is set to be turned on by the piston body 42a lowered to the lowest position, and turned off when the piston body 42a is located at a position other than the lowest position.

On the other hand, as shown in FIG. 6A, on the upper surface of the second outer flange portion 40d of the cylinder portion 40, a total of nine connection holes 74a to 74i are provided in the substantially right half portion of the drawing. Has been formed. Here, the respective connection holes 74a to 74i are set so that the second connection ports 60b are respectively connected. That is, in this embodiment, as described above, the second connection port 60b
Are provided corresponding to the nine second air hoses 32b. Here, for convenience of illustration, the first, fifth, and ninth
The second connection port 60b is connected to the connection holes 74a, 74e, and 74i of FIG.

Here, in FIG. 2, for convenience of drawing, the ninth connection hole 74i is shown as a representative at this cross-sectional position, but in a state of communicating with the respective connection holes 74a to 74i. Communication chambers 76a to 76i are formed in the lower surface of the second outer flange portion 40d so as to open there. Here, each of the communication chambers 76a to 76i is formed elongated so as to extend inward in the radial direction from the communication position with the corresponding connection hole 74a to 74i.

On the other hand, the communication chambers 76a to 76i are closed by the outer flange portion 44c of the inner cylinder 44 attached to the lower surface of the second outer flange portion 40d of the cylinder portion 40. A connection pipe 98a, which will be described later, is formed on the outer flange portion 44c in a state of being opened at radially inner portions of the communication chambers 76a to 76i.
9 connection pipe insertion holes 78a to 78 into which ~ 98i are inserted respectively
i is formed so as to penetrate in the thickness direction. In other words,
Connection hole 74a communicated with each other through each communication chamber 76a-76i
~ 74i and connecting pipe insertion holes 78a to 78i are staggered along the radial direction, and the latter is set to be located inward of the former. With this configuration, the connection groove for locking the handler to be described later can be inserted in such a way that the locking groove is biased radially inward without increasing the overall size of the attaching / detaching mechanism 10. Hole 78a
It can be formed in the portion of the shank main body that is located radially outward of ~ 78i.

Further, as shown in FIG. 6A again, the above-described relay board 66
A plurality of, in this embodiment, fifteen connection pins 80a-80o are fixed on the top in an upright state. Here, the connection pins 80a to 80o correspond to the first connector 62 described above.
Each a is set to be attached in a connected state.

Incidentally, the main feature of the present invention is that the number of connection pins 80a to 80o is 15, which will be described in detail later, but this cable 32c is configured as a serial interface cable. This is because it is set to communicate between the robot controller 28 and the hand mechanism 30 through. In other words, conventionally, the robot controller and the hand mechanism are set to be connected to each other by a cable as a parallel interface cable, and as a result, under the same conditions, the arrangement of the connecting pins is reduced. The number will be increased to 32.

However, in this invention, since the serial interface cable is used, the connection pins 80a-8
The number of 0's arranged will be reduced to 15. As a result, the installation area of the relay board 66 can be small, and the number of the first connectors 62a can be small, so that the overall outer shape of the attachment / detachment mechanism 10 can be downsized and the weight can be reduced. You will be able to do it.

On the other hand, the connection pins 80a to 80o on the relay board 66 are electrically connected to the connection bushes 84a to 84o formed on the lower surface of the outer flange portion 44c of the inner cylinder 44 via the connection rods 82a to 82o, respectively. It is connected. That is, the outer flange portion 44c is formed with a through hole 44d that vertically penetrates to accommodate the connection bushes 84a to 84o, and the connection bushes 84a to 84o are formed.
The internal space of is defined such that the connection terminal described later is inserted and electrically connected.

In addition, each connection rod 82a-82o corresponds to the second
Through the through hole 40f formed so as to vertically penetrate the outer flange portion 40d of the corresponding connection bush 84a.
It is fitted on the upper part of ~ 84o and is electrically connected, and in this way, each connection pin 80a ~ 80o and connection bush 84a ~ 8
0o are electrically connected to each other.

With the above description, the description of the holder 34 that defines one component of the hand attaching / detaching device 10 is completed, and then the shank 36 that defines the other component of the hand attaching / detaching device 10 will be described.

The shank 36 is commonly configured for various hand mechanisms which are detachably attached to the vertical arm 20 of the robot 12 through the hand attaching / detaching device 10, and its upper surface is attached / detached as shown in FIG. A shank main body 86 set so as to define the lower side of the surface PL, a connecting cylinder 90 fixed below the shank main body 86 via a bolt 88, and a lower surface of the connecting cylinder 90 via a bolt 92. It is mainly composed of a fixed mounting plate 94.

Here, the shank main body 86 is provided with a disc-shaped attachment / detachment member 86b in the center of which a circular through hole 86a into which the ball support cylinder 48 of the holder 34 is loosely inserted is formed.
A cylindrical locking tubular portion 86c is integrally formed on the upper surface of the attachment / detachment member 86b so as to surround the through hole 86a and stand upright from the peripheral edge of the opening. This locking cylinder 86c
An inner flange portion 86d is formed at the upper end of the inner flange portion 86d, and the inner surface of the inner flange portion 86d has a hooking inner portion that can be hooked on the outer upper portion of the ball 52 supported by the ball support cylinder 48 described above. A tapered surface 86e is formed.

The hooking inner taper surface 86e is inclined so that its diameter increases as it goes upward. Further, the inner peripheral surface of the inner flange portion 86d has the above-mentioned locking sleeve 68d.
Is set to face the outer peripheral surface of the with a slight interval.

On the other hand, on the lower surface of the outer peripheral portion of the detachable member 86b of the shank main body 86, a falling portion 86f having a predetermined thickness is integrally formed over the entire circumference, and the hand placement table ( (See FIG. 7.) A locking groove 86g that is locked to 96 is formed over the entire circumference.

<Explanation of Hand Stand 96> Here, for convenience of explanation, the explanation of the shank 36 is temporarily interrupted and the configuration of the hand stand 96 will be explained.

As shown in FIG. 1, a plurality of hand mounts 96 are provided on the hand exchanging station 13 via the mounts 17, and each has the same shape. This hand stand 96
7A, as shown in FIG. 7A, is provided with a plate-shaped rack main body 96a having a thickness to be fitted into the locking groove 86g of each shank 36, and the front end surface of this rack main body 96a is to receive the shank 36 largely. Is formed with a substantially semicircular recess 96b. Further, reinforcing ribs 96c are integrally formed on the lower surfaces of both side edges of the rack main body 96a. As a result, when the hand placing table 96 is viewed from the front, both end portions are formed as shown in FIG. 7B. Will appear as opposite L-shapes facing each other.

In other words, in this embodiment, the hand rest 96
The whole is formed from a thin plate having a thickness sufficient to fit in the locking groove 86g, but a pair of reinforcing ribs 96c are integrally attached and set so that its rigidity is sufficiently secured. Has been done. In this way, the rigidity of the hand stand 96 is sufficiently ensured, so that the shank 36 hung on the hand stand 96 is in a state in which the hand mechanism 30 is connected to the lower portion thereof, its height position, in detail, Therefore, the height position of the upper surface of the shank main body 86 can always be kept constant.

Here, the shape of the substantially semicircular recess 96b described above is
Details will be described with reference to the drawings.

The recess 96b is formed at both end edges, a pair of the tip end tapered portion 96b ₁ formed from the inclined surface towards the outside, is formed inward at these tip state where the tapered portion 96b continued continuously in ₁ It is formed of a pair of straight line introducing portions 96b ₂ and a semicircular portion 96b ₃ formed of an arc surface having a line segment D connecting the ends of these straight line introducing portions 96b ₂ with a diameter d ₁ .

Here, the center position D ₁ of the semicircular portion 96b ₃ is defined by the position of exactly half of the line segment D, that is, the center position of the arc surface. The diameter d ₁ is set to be slightly larger than the outer diameter of the locking groove 86g described above. The distance e ₁ between the reinforcing ribs 96c is set to be slightly larger than the outer shape of the attaching / detaching member 86b described above.

As is clear from FIG. 7C, the boundary portion between the straight line introducing portion 96b ₂ and the semicircular portion 96b ₃ in the concave portion 96b, that is, the portion of the rack main body 96a through which the line segment D passes is located here. A ball plunger 96d for locking the position of the inserted shank 36 is provided.

Next, referring to FIG. 7D, the hand exchange station 13
The arrangement state of the plurality of hand stands 96 in, that is, the relative positional relationship with the robot 12 will be described in detail.

In the following description of the arrangement of the hand stand 96, the hand exchange station 13 will be described for the sake of simplicity.
In addition to the above-mentioned hand stand 96, a second hand stand
Description will be made under the assumption that 97 are provided and that there are a total of two hand stands 96 and 97. Here, the configuration itself of the second hand placement table 97 is exactly the same as the configuration of the (first) hand placement table 96 described above.

First, as shown in FIG. 7B, the first and second hand mounts
96 and 97 are sequentially arranged along the radial direction of the support column 14 of the robot 12, and more specifically, the center point (center of gravity) C _{1 of} the first hand placement table 96 and the center of the second hand placement table 97. Point (center of gravity)
C ₂ is set so as to pass through a predetermined radius R ₀ passing through the first rotation axis A ₁ .

Here, the center position of the semicircular recess 96b of the first hand mounting table 96 is set to D _1, and the semicircular recess 97 of the second hand mounting table 97 is set.
Assuming that the center position of b is D ₂ , the center position D ₁ of the first hand stand 96 is on the arc line L ₁ of radius R ₁ centered on the center axis of the column 14, that is, the first rotation axis A _1. And the center position D ₂ of the second hand stand 97 is located on the arc line L ₂ of radius R ₂ about the first rotation axis A _2. ing.

Furthermore, the longitudinal centerline l ₁ of the first hand stand 96 is
So that it becomes the cutting line of the arc line L _{1 at} the center position D ₁ , and
The center line l _{2 in} the longitudinal direction of the second hand stand 97 is at the center position.
As the tangential arc line L ₂ in D _2, they are respectively set. In other words, the opening surface of the recess 96b of the first hand placement table 96 is set to be orthogonal to the cutting line (l ₁ ) passing through the center position D ₁ on the corresponding arc line L ₁ .

In this way, the shank 36 moving along the arc line L ₁ along the arc line L ₁ can be smoothly fitted into the recess 96b without contacting the peripheral surface defining the recess 96b,
The shank 36 can be smoothly put in and taken out of the first hand stand 96. Similarly, the shank 36 moving along the arc line L ₂ along the arc line L ₂ smoothly fits into the recess 97b without abutting on the peripheral surface defining the recess 97b. The 2nd hand stand 97 can be smoothly put in and taken out.

Incidentally, in this embodiment, the radius R ₁ which defines the arc lines L ₁ described above, the radius R ₂ which defines an arc line L _2, the first
Rotation length of the horizontal arm 16, that is, the distance F ₁ from the _first rotation axis A ₁ to the second rotation axis A _2, and the rotation length of the second horizontal arm 18, that is, the second rotation. in relation to the distance F ₂ from the axis a ₂ to the center axis of the vertical arm 20, it is set in the range expressed by the following inequality.

R ₁ <R ₂ ≦ (F ₁ + F ₂ ) <again, description of shank 36> In the shank main body 86 configured as described above, the inner flange portion 86 d is enlarged as shown in FIG.
At the outer peripheral edge of the upper surface of the inner cylinder body 4 of the inner cylinder 44 of the inner cylinder 44, the inner flange portion 86d of the shank body 86 is inserted into the shank 36 that is hooked by the shank holder 96 when the holder 34 descends from above.
An outer tapered surface 86h is formed over the entire circumference so that the outer tapered surface 86h can be easily fitted into the inner peripheral surface of 4a in a sliding contact. In other words, as described above, the outer tapered surface 86h of the inner flange portion 86d of the shank body 86 is such that the inner cylinder body of the inner cylinder 44 is
By engaging with the lower edge of the inner peripheral surface of 44a, even if the central axes of the holder 34 and the shank 36 are slightly deviated, the relative positions of the two change and the central axes of the two are accurately aligned. Thus, the shank main body 86 is guided so as to be securely fitted into the inner cylinder 44.

On the other hand, on the inner peripheral edge of the upper surface of the inner flange portion 86d, the inner cylinder 44
After the shank main body 86 is fitted in the inside, the shank main body 86
The inner tapered surface 86i for insertion is formed over the entire circumference so that the inner peripheral surface of the inner flange portion 86d can be securely fitted in the outer peripheral surface of the locking sleeve 68 in a sliding contact. There is.

Here, on the upper surface of the shank main body 86, as shown in FIG. 6B, at the positions corresponding to the above-described connection pipe insertion holes 78a to 78i, the projections are projected upward so that they can be inserted from below. The connection pipes 98a to 98i are arranged in this state. Then, the holder 34 descends and the holder 34 and the shank 36 are connected to each other, that is, the inner cylinder 44.
In a state where the lower surface of the outer flange portion 44c and the upper surface of the attachment / detachment member 86b of the shank body 86 are in contact with each other, the upper ends of the respective connection pipes 98a to 98i have corresponding connection pipe insertion holes 78.
It is set so as to be inserted into the communication chambers 76a to 76i through a to 78i.

Further, on the upper surface of the shank main body 86, as shown in FIG. 6B, at the positions corresponding to the connection bushes 84a to 84o described above, the connection terminals are projected upward so that they can be inserted from below. 100a to 100o are provided. Then, when the holder 34 comes down and the holder 34 and the shank 36 are coupled to each other, the connection terminals 100a to 100i are connected.
The upper ends of are connected to the corresponding connection bushes 84a to 84i and are set to be electrically connected.

Further, on the upper surface of the shank main body 86, as shown in FIG. 6B, a bolt 92 is rotated from above to attach the mounting plate 94 to the connecting cylinder 90.
The four through holes 102a to 102d for fixing are formed at equal intervals along the circumferential direction so as to penetrate in the thickness direction. It should be noted that these through holes 102a to 102d are arranged in a state of being biased outward in the radial direction with respect to the connection pipes 98a to 98i and the connection terminals 100a to 100o in order to avoid competition with the connection pipes 98a to 98i.

On the other hand, as shown in FIG. 6B and FIG.
A slit 104 for measurement is formed on the upper surface of the inner flange portion 86c of 86 in a state of being cut downward. As is clear from FIG. 8, the slit 104 is formed so that its lower end ends just below the lower end edge of the latching inner taper surface 86e. Like this
By forming 4, the inner taper surface 8 for locking is actually
This slit is used when forming 6e by machining.
Through 104, it is possible to machine while looking at the taper surface being machined. That is, this slit 104
Through this, it becomes possible to form the hooking inner taper surface 86e while detecting the processing position with a detection device utilizing vision, for example.

As a result, the latching inner taper surface 86e is accurately defined in its shape and size. Thus, as shown in FIG. 2, the outer taper surface 86e is accurately positioned.
A state of holding six balls 52 between 54a and 54a is achieved, and therefore, according to this embodiment, the hand attaching / detaching device 10
When the coupling state is defined in the above, the outer flange portion 44 of the inner cylinder 44 on the holder 34 side is attached on the attachment / detachment surface PL.
The lower surface of c and the upper surface of the shank main body 86 on the shank 36 side are in close contact with each other, and a good joined state without play is achieved.

As shown in FIG. 8, the connecting member 86b of the shank 86 is
In order to position the shank 86 and the holder 34 connected thereto in the rotational direction, a rotation positioning member 105 is formed on a part of the upper surface of the above so as to project upward from the upper surface thereof. Although not shown, a concave portion corresponding to the rotary positioning member 105 is formed on the bottom surface of the outer flange portion 44c of the inner cylinder 44. Here, this rotary positioning member 10
As is clear from FIG. 6B, 5 is composed of a rectangular parallelepiped, and a pair of surfaces of the rectangular parallelepiped facing each other are set as surfaces orthogonal to the circumferential direction so as to define the rotational direction position. C-cut taper surfaces 105a and 105b are formed on the upper edge of the position restriction surface.

In this way, instead of a cylinder, the rotation positioning member is made from a rectangular parallelepiped.
By configuring 105, positioning will be achieved by surface contact. As a result, even if the positioning operation is repeated and the position-regulating surface is partially worn (evenly worn), since it is regulated by surface contact, the other non-abraded portion is surface-contacted and the position regulation surface is restricted. The effect is achieved, and in this way, the rotational positioning effect is surely exhibited.

On the other hand, the connecting tube 90 that constitutes the shank 36 is formed in a cylindrical shape that is open from above or below and the main body portion 90a and the main body portion 9a.
It is integrally formed with an inner flange portion 90b formed at the upper end of 0a. Inside this connecting tube 90, a pair of upper and lower circuit boards 106a and 106b are provided with an inner flange portion via a spacer 108.
It is arranged so as to be suspended from the lower surface of 90b. Here, the upper circuit board 106a and the above-mentioned connection terminals 100a to 10a
0o is electrically connected to each other via connection rods 110a to 110o arranged in a state of vertically penetrating the detachable member 86b of the shank main body 86 and the inner flange portion 90b of the connecting tube 90. The upper circuit board 106a and the lower circuit board 106b are electrically connected to each other via a connection board (not shown).

Further, the outer peripheral surface of the main body portion 90a of the connecting cylinder 90 is formed with nine connection port connection holes 112a to 112i opened corresponding to the above-mentioned nine connection pipes 98a to 98i, respectively. Has been done. Here, the connection holes 112a to 112i are
The connection / removal members 86b of the shank main body 86 and the inner flange portion 90b of the connection tube 90 are connected to the connection pipes 98a-98i through the connection passages 114a-114i, respectively, which are arranged so as to pass through in the vertical direction. It is connected to the.

And among the above-mentioned nine connection holes 112a to 112i, the connection holes 112a, 112e, 112i corresponding to the first, fifth and ninth connection bushes 74a, 74e, 74i are shown in FIG. 6C. Like 3
Book connection hoses 115a, 115b, 115c connect to connection ports 116a, 1
These three connecting hoses 11 are connected via 16b and 116c.
5a to 115c are provided in the hand mechanism 30.

Here, as shown in FIG. 2, a serial signal sent from the robot controller 28 is converted into a parallel signal, and a signal sent to the robot controller 28 is sent to the pair of upper and lower circuit boards 106a and 106b described above. From the serial signal to the serial signal is configured,
Signals from both circuit boards 106a and 106b are respectively passed through first and second connection line groups 118a and 118b having second and third connectors 62b and 62c at one end, as shown in FIG. And is connected to the hand mechanism 30.

The first and second connection line groups 118a and 118b are connected to each other by the connecting tube 9
In order to take out once from 0, as shown in FIG. 6C, a pair of openings 120a and 120b are formed in the peripheral wall forming the main body portion 90a so as to penetrate in the thickness direction. By forming the openings 120a and 120b in this manner, the above-described first and second connection line groups 118a and 118b are taken out to the outside of the shank 36 through the openings 120a and 120b. It will be connected to the hand mechanism 30.

On the other hand, the above-mentioned four bolts 92 are arranged in total, and in order to mount these four bolts 92, the bolts 92 are located immediately below the through holes 92a to 92d and communicate with each other. On the outer peripheral surface of the main body portion 90a of the connecting cylinder 90, four recesses 1
22a to 122d are formed. Here, each recess 122a-122
The height of d is set to be slightly longer than the height of each bolt 92. With this configuration, each bolt 92
After being temporarily stored in the corresponding recesses 112a to 112d from the side, the mounting plate 94 is rotated by a driver (not shown) inserted from above through the corresponding through holes 102a to 102d.
It is ready to be screwed into the
It is possible to fix 94 to the connecting cylinder 90.

As shown in FIG. 2, the internal space of the shank 36 is
A partition plate 124 is sandwiched between the shank main body 86 and the connecting tube 90 so as to be vertically separated from each other. By providing the partition plate 124, the hand stand with the shank 36 separated from the holder 34.
In the state of being held by 96, that is, in the state where the shank 36 is exposed to the outside, the circuit boards 106a and 106b are still located in the closed space, and the dustproof effect of these circuit boards 106a106b is achieved. It will be.

Here, since the partition plate 124 is provided in this way, as is apparent from FIG. 2, in the state where the holder 34 is coupled to the shank 36, the space where the lower portion of the piston 42 is located, that is, The volume of the space surrounded by the partition plate 124, the shank main body 86 and the ball support cylinder 48 is limited to be small. Then, when the space described above is closed along with the lowering of the piston 42 in the attaching / detaching operation described later, the lower part of the piston 42 projects into the closed space, and the air in the closed space is compressed, so-called. The elastic effect is exerted to act as an opposing force with respect to the downward movement of the piston 42.

However, in this one embodiment, in order to achieve the smooth lowering operation of the piston 42 by preventing the generation of unnecessary opposing force against the lowering operation of the piston 42,
The piston body 42a of the piston 42 and the body portion 5 of the locking member 54
A communication hole 126 is formed so as to penetrate through 4b.
The communication hole 126 is formed so that its upper end opens on the outer peripheral surface of the piston main body 42a which is always positioned above the ball support cylinder 48, and its lower end opens on the lower surface of the main body portion 54b of the locking member 4.

Since the communication hole 126 is formed in this way, in this embodiment, even if the piston 42 moves up and down, the space described above communicates with the outside through the communication hole 126. The air inside does not exert the elastic force, and the smooth lowering operation of the piston 42 is achieved.

Further, the above-mentioned mounting plate 94 is configured to also function as an upper plate of the hand mechanism 30 shown in FIG. 10A. Thus, in this embodiment, the number of components is reduced, the overall weight is reduced, and the length in the Z-axis direction is set to be short, so that the overall size can be reduced. Become.

In the hand attaching / detaching mechanism 10 configured in this way, the ball support cylinder 48, the locking member 54, and the shank main body 86, which form the contact portion, are all set to be formed of steel. The remaining components are all made of aluminum for the purpose of weight reduction.
Here, in FIG. 2, in order to facilitate understanding, consideration has been given to show the cross-sectional shape by hatching with two steel parts and hatching with one aluminum part. There is.

Thus, in this embodiment, most of the components of the hand attaching / detaching mechanism 10 are made of aluminum,
The above-mentioned weight reduction is surely achieved.

<Example of Hand> Here, the above-mentioned hand mechanism 30 is variously arranged according to the gripping mode, and the robot 12 can be mounted with any hand mechanism, as described above. A hand exchange station 13 holding a plurality of hand mechanisms having the structure is provided, and each hand exchange station 13 is supported by a corresponding hand stand 96.

As an example of the hand mechanism 30, FIGS. 10A and 10B show the configuration of the first hand mechanism 30A, and FIG. 10C shows the configuration of the second hand mechanism 30B.

This first hand mechanism 30 is basically the same as the component gripping hand device disclosed in Japanese Patent Application No. 63-207359 filed by the same applicant as the applicant of the present application. Although the description of the configuration is omitted, three arms 128a to 128c whose pivot points are respectively three points which are not on the same straight line.
The fixed fingers 130a to 130c, which are provided at the tips of the arms 128a to 128c, are fixed so as to extend along the vertical direction, and have hollow interiors, and are housed in the respective fingers 130a to 130c, and are vertically moved. And movable fingers 132a to 132c that can move back and forth along the direction.

Each arm 128a-128c has a corresponding drive motor.
To M ₁ ~M _3, so as to be driven rotated around the above-described points, and is connected via respective reduction mechanism 134A～134c.
Here, each of the drive motors M _{1 to} M ₃ is composed of a pulse motor. That is, each of the drive motors M _{1 to} M ₃ is connected to a predetermined connection line of the above-described connection line group 118a, 118b, and is rotated to an arbitrary rotation position based on a control signal from the robot controller 28. It is set to be driven and controlled to be dynamically driven.

On the other hand, each movable finger 132a-132c is configured to function as a piston when the corresponding fixed finger 130a-130c is a cylinder, and each fixed finger 130a-130c.
The above-mentioned three connection hoses 115a to 115c are respectively connected to the upper ends of the.

On the other hand, since the second hand mechanism 30B is basically the same as the gripping device for the work W disclosed in Japanese Patent Application No. 1-230412 filed by the applicant of the present application, Although the detailed description of the configuration is omitted, the second hand mechanism 30B includes a cylindrical grip body 214 at the center thereof, and the grip body 214 is provided directly below the mounting plate 94 described above. , Are connected to each other via a plurality of connecting rods 216 while being separated by a predetermined distance. Where this grip body
At the upper end of 214, three arm portions 218a, 218b, 218c extending outward in the radial direction from now on are arranged at equal intervals along the circumferential direction, in other words, at an angle of 120 degrees, they are integrated. Is formed in.

On the other hand, the lower part of the grip body 214 has three arms 218a, 218a.
Similarly, three pairs of upper and lower guide rods 220a ₁ and 220a ₂ ; 220b ₁ and 220b ₂ ;
220c ₁ and 220c ₂ are integrally connected. Here, the upper and lower pairs of guide rods 220a ₁ , 220a ₂ ; 220b ₁ , 220b ₂ ; 220c ₁ , 22
The 0c _2, gripping claws 222a, 222b, 222c are respectively slidably supported. That is, the three gripping claws 222a, 222b, 222c are reciprocally supported below the corresponding arm portions 218a, 218b, 218c along their respective extending directions.

Here, the second hand mechanism 30B includes a drive mechanism 224 that integrally and reciprocally drives these three gripping claws 222a, 222b, 222c in the radial direction along with each other.

The drive mechanism 224 includes one drive motor 226 fixed to the lower surface of the mounting plate 94 described above. On the other hand, on the upper surface of the grip body 214 described above, a large diameter spur gear 228 for driving is provided.
Are rotatably supported around a rotation axis aligned with the drive axis of the drive motor 226. And the drive motor 226
The drive shaft 226a is connected to the spur gear 228 via a connecting shaft 230. In this way, the spur gear 228 is rotationally driven by the drive motor 226.

On the other hand, the driven small spur gears 232a, 232b, 232c are rotatably supported around the vertical axis at the tip of each arm 218a, 218b, 218c. Then, in order to connect these three driven spur gears 232a, 232b, 232c and the drive spur gear 228 to each other, one endless toothed timing belt 234 is arranged with the teeth facing inward. It is set up.

Here, in order to keep the timing belt 234 extending radially in three directions as shown in FIG. 10D, the six regulation rollers 236 are provided on the outer periphery of the spur gear 228.
The a, 236b, 236c, 236d, 236e and 236f are rotatably rotatably supported on the upper surface of the grip body 214. That is, the timing belt 234 is made up of the three arms 218a, 218b, 2 by the six restriction rollers 236a, 236b, 236c, 236d, 236e, 236f.
The outer peripheral surface of the spur gear 228, which corresponds to the base end portion of 18c, does not engage with the three parts, but can engage with the outer peripheral surface other than these three parts, and the three driven spur gears 232a, 232b. It becomes possible to mesh with the outer portion of the outer peripheral surface of the 232c.

The pair of regulating rollers 236a, 236b; 236c, 236d; 236e, 236f corresponding to the driven spur gears 232a, 232b, 232c are the second
As shown in the figure, the belt separation width A in the radial portion of the timing belt 234 is positioned so that it is constant in each radial portion.

In this way, the timing belt 234 meshes with a part of the outer peripheral surface of the driving spur gear 228, then meshes with the outer peripheral surface of the first driven spur gear 232a, and again,
After meshing with a part of the outer peripheral surface of the drive spur gear 228, it meshes with the outer peripheral surface of the second driven spur gear 232b, and again again with one of the outer peripheral surface of the drive spur gear 228. After meshing with the portion, it is wound endlessly so as to mesh with the outer peripheral surface of the third driven spur gear 232c.

On the other hand, the portion of the timing belt 234 that extends radially outward along the first arm portion 218a and the first grip claw 222.
A first connecting member 238a is formed over both of them in order to connect a with each other, and the upper and lower ends of the first connecting member 238a are fixed to the timing belt 234 and the first grip claw 222a, respectively. ing. Similarly, the second and third grip claws 222b and 222c are connected to the timing belt 234 via the second and third connecting members 238b and 238c, respectively.

The grip claws 222a, 222b, 222c are connected to the corresponding connecting members 238.
It is set so as to be held at the position of the same radial distance from the center portion in the state of being connected to the timing belt 234 by a, 238b, 238c.

Since the drive mechanism 224 is configured in this way, the spur gear 228 for driving is rotationally driven by the activation of the drive motor 226, and the rotational force of the spur gear 228 is generated by the three timing belts 234. It is similarly transmitted to the grip claws 222a, 222b, 222c. As a result, the three grip claws 222
The a, 222b, 222c are reciprocally moved along the radial direction in a state of being synchronized with each other. In this way, the second
According to the hand mechanism 30B, even when cylindrical objects having different diameters are sequentially gripped as a work, it is possible to grip them while changing their centers.

Through the hand attaching / detaching mechanism 10 configured as described above,
The attaching / detaching operation of the hand mechanism 30 (when the first and second hand mechanisms 30A and 30B need not be distinguished from each other, the reference numeral 30 is used in a representative state) with respect to the vertical arm 20, will be described below.

First, as shown in FIG. 2, the state in which the hand attaching / detaching mechanism 10 connects the hand mechanism 30 to the vertical arm 20 is the cylinder chamber.
This is achieved by the state in which the working compressed air is not introduced into the inside of 58 through the first air hose 32a, and the piston 42 is biased upward by the biasing force of the coil spring 56. In this coupled state, the outer tapered surface 54a of the locking member 54 is also biased upward in response to the upward bias of the piston 42, and accordingly, each ball 52 is pushed outward in the radial direction. . As shown by the alternate long and short dash line in FIG. 4, each ball 52 protrudes outward in the radial direction from the corresponding ball support hole 48d and is formed on the inner flange portion 86d of the shank 36, which is an inner taper surface for engagement. It will come into contact with 86e.

Thus, in this embodiment, each ball
By holding 52 between the latching inner taper surface 86e and the outer taper surface 54a, the shank 36 is prevented from coming out downward from the holder 34.
Securely hold, in other words, the hand mechanism 30 is a vertical arm.
It will remain firmly connected to the 20.

On the other hand, when releasing the hand mechanism 30 from this combined state, the working compressed air is introduced into the cylinder chamber 58 via the first air hose 32a. By this introduction, as shown in FIG. 5, the piston 42 is pushed downward against the biasing force of the coil spring 56. As a result,
As shown by the chain double-dashed line in FIG. 4, the outer tapered surface 54a descends so that the outer peripheral surface of the main body portion 54b of the retaining member 54 is brought to a position facing the ball support hole 48d.

Here, when the hand mechanism 30 is removed from the vertical arm 20, the shank 36 to which the hand mechanism 30 is connected is set to be supported by the corresponding hand stand 96, which will be described later. That is, the shank 36 is locked to the hand stand 96 so that it cannot move up and down. Therefore, as the holder 34 of the hand attaching / detaching mechanism 10 is lifted as the vertical arm 20 is raised, the balls 52 are biased radially inward in accordance with the inclination of the hooking inner taper surface 86e.
The body portion 54b comes into contact with the outer peripheral surface of the body portion 54b.

As a result, the ball 52 is completely hidden in the ball support hole 48d. In this way, the ball 52 connecting the holder 34 and the shank 36 to each other no longer exists, so that the holder 34 is pulled upward from the shank 36, in other words, the hand mechanism 30 moves vertically. The vertical arm 20 is ready to be lifted with the hand mechanism 30 separated. In this way, the ninth
As shown in the figure, the vertical arm 20 is pulled upward, so that the holder 34 of the hand attaching / detaching mechanism 10 moves to the shank 36.
To be lifted upwards.
That is, the hand 30 is detached from the lower end of the vertical arm 20 via the hand attaching / detaching mechanism 10.

In the releasing operation of the hand attaching / detaching mechanism 10, that is, in the pulling operation of the holder 34 from the shank 36, the portions of the shank 36 and the holder 34 that are substantially inside are the lower portion of the locking member 20b of the piston 42 and Only the support cylinder main body 48a of the ball support cylinder 48, and its length is limited to an extremely short value as indicated by reference numeral 1 in FIG.

As a result, in this embodiment, the stroke along the Z-axis direction for releasing the hand mechanism 30 from the vertical arm 20 may be at least the distance l described above,
The replacement time will be set short.

As described above in detail, in this embodiment, the inner peripheral surface of the inner flange portion 86d of the shank main body 86 is provided with the inner tapered surface 86e for locking. As a result, according to this embodiment, therefore, the overall structure can be simplified and the weight can be improved, the operating characteristics can be improved, and the distance along the Z-axis direction for attachment and detachment can be shortened. The setting time can be shortened, and the time for attachment / detachment can be shortened, resulting in improved work efficiency.

Next, the replacement work of the hand mechanism 30, which is a feature of the present invention, specifically, the vertical arm 20 through the hand attaching / detaching mechanism 10.
A method of exchanging the first hand mechanism 30A attached to the lower end of the second hand mechanism 30B which is on standby and held on the second hand stand 97 of the hand exchanging station 13 will be specifically described.

First, as shown in FIG. 1, in a state in which the first hand mechanism 30A is connected to the lower end of the vertical arm 20 via the hand attaching / detaching mechanism 10, predetermined parts for unillustrated parts corresponding to the first hand mechanism 30A are provided. Pick and place operation is executed. Then, this first hand mechanism 30
If other parts that cannot be picked by A must be picked and placed, the first hand mechanism 30A is removed to the empty first hand stand 96, and the picking of other parts is performed. Second hand mechanism 30 suitable for movement
You will have to exchange it for B.

When it is necessary to replace the hand mechanism 30 in this way, the robot controller 28 first drives only the second drive motor 22 to move the first rotation axis A ₁ to the central axis of the vertical arm 20. The second horizontal arm 18 is rotationally driven around the second rotation axis A _{2 with} respect to the first horizontal arm 16 so that the distance to the first radius R ₁ becomes the above-mentioned first radius R ₁ .

After that, the driving of the second drive motor 22 is stopped and the second rotation axis A ₂ is fixed, that is, the second horizontal arm 18
The angle with respect to the first horizontal arm 16 is fixed, and the center of the shank 36 to which the first hand mechanism 30A is connected is set so as to be able to move on the arc locus L ₁ having the radius R ₁ described above. Drive only the first drive motor 21 to
The shank 36 to which the hand mechanism 30A of the above is connected to the empty first hand stand 96 of the hand exchanging station 13 so that the shank 36 attached to the hand attaching / detaching mechanism 10 is supported. Move from. As a result, the shank 36 is smoothly supported in a state where the rack main body 96a that defines both sides of the recess 96b of the hand placing table 96 is fitted into the locking groove 86g from both sides.

Then, with the shank 36 being completely supported by the first hand stand 96, the robot controller 28 activates an air pressure mechanism (not shown), and through the first air hose 32a,
Compressed air is introduced into the cylinder chamber 58 of the hand attaching / detaching mechanism 10. As a result, as described above, the released state of the hand attaching / detaching mechanism 10 is defined, and the holder 34 is in a state in which it can be separated upward from the shank 36.

After that, the robot controller 28 confirms the separable state of the detachable mechanism by the ON operation of the lowermost position confirmation sensor 70 described above, and then activates the third drive motor 24 to vertically move the vertical arm 20. It drives so that it may move upwards along it. In this way, the holder 34 attached to the lower end of the vertical arm 20 is lifted from the shank 36 supported by the hand stand 96, and is separated upward at the attachment / detachment surface PL.

After that, when it is detected that the upward movement amount of the vertical arm 20 has reached the above-described separation stroke l, the robot controller 28 stops the driving of the third drive motor 24 and only the second drive motor 22 is stopped. Is activated to maintain the vertical position of the vertical arm 20 and the distance from the first rotation axis A ₁ to the central axis of the vertical arm 20 becomes the second radius R ₂ described above. The horizontal arm 18 is rotationally driven with respect to the first horizontal arm 16 about the second rotation axis A ₂ .

After that, the driving of the second drive motor 22 is stopped and the second rotation axis A ₂ is fixed, that is, the second horizontal arm 18
Is fixed to the first horizontal arm 16 and the center of the holder 34 of the hand attaching / detaching mechanism 10 is an arc locus of radius R ₂ described above.
With the setting so that it can move on L ₂ ,
The second hand mechanism 30B which drives only the drive motor 21 of the second hand and moves on the arc locus L ₂ to newly attach the second hand mechanism 30B.
Above, and the first drive motor 21 is stopped at this point.

In this way, the hand attaching / detaching mechanism 10 is the second hand mechanism.
The fourth drive motor 2 when moving directly above 30B
4 is activated and rotated about its central axis, and the rotational position of the second hand mechanism 30B to be connected is accurately aligned with its own rotational position.

After this, the third drive motor 22 is activated to activate the vertical arm.
20 is lowered and the vertical arm 20 is lowered by the stroke distance 1 described above, and the holder 34 moves the second hand mechanism 30B.
When placed on the connected shank 36,
The drive motor 22 is stopped.

After that, the robot controller 28 stops the operation of the pneumatic mechanism described above and releases the pressure in the cylinder chamber 58. As a result, the piston 42 is lifted by the urging force of the coil spring 56, and each ball 52 is pushed by the outer tapered surface 54a of the locking member 54 and is biased outward in the radial direction, from the outer peripheral surface of the ball support cylinder 48. It projects radially outward. In this way, as shown in FIG. 2, each ball 52 is held between the latching inner taper surface 86a and the outer taper surface 54a, and the balls 52 are held.
34 and shank 36 are joined together. That is, the second hand mechanism 30B is connected to the vertical arm 2 via the hand attaching / detaching mechanism 10.
It will be connected to the bottom of 0.

And the robot controller 28 is the second drive motor.
In the state where 22 is stopped, only the first drive motor 22 is started again, and the second hand mechanism 30B is connected to the shank 3
6 from the recess 97b of the second hand stand 97 to the second radius R ₂
Move it horizontally from the opening side so that it exits through the arc locus L ₂ of.

As a result, the second hand mechanism 30B, which is connected to the lower end of the vertical arm 20 via the hand attaching / detaching mechanism 10, is smoothly detached from the second hand stand 97. In this way, the hand mechanism 30 The replacement work is completed.

Thus, according to the hand exchange method of this embodiment,
Without using expensive CP control and using inexpensive PTP control, the hand mechanism 30 can be replaced smoothly and reliably without the shank 36 coming into contact with the end faces of the hand placing tables 96 and 97. It will be a matter.

It is needless to say that the present invention is not limited to the configuration of the above-described embodiment, and can be variously modified without departing from the gist of the present invention.

For example, in the above-described embodiment, the hand mechanism 30 is exchanged using the scalar type robot 12, but the present invention is not limited to such a configuration, and the robot of the cylindrical coordinate system is used. Can be similarly applied to.

In addition, in the above-described embodiment, FIGS.
Through the hand attaching / detaching mechanism 10 having the configuration shown in the figure, the hand mechanism
Although it has been described that the 30 is attached and detached, the present invention is not limited to such a configuration, and can be applied to a hand exchange method using the hand attachment / detachment mechanism 10 of any configuration.

[Effects of the Invention] As described in detail above, the hand exchange method according to the present invention includes the first and second arms, and these first and second arms are provided around the first and second axes, respectively. An assembling system that moves a hand detachably attached to a tip of a second arm to a predetermined position by rotating and driving the parts to perform an assembling work of parts. In a method of exchanging a hand in an assembly system for executing work, a distance between the first shaft and the hand attached to a tip of the second arm is set to a distance of a rack from which the hand is detached and placed. The first step of rotating and driving the second arm around the second axis so that the distance is the same as the distance between the mounting portion and the first axis, and fixing the second axis. A second step of
And a third step of rotating the first arm around the first axis and attaching the hand at the tip of the second arm to a corresponding rack.

Therefore, according to the present invention, it is possible to provide a hand exchanging method capable of achieving smooth take-in / take-out of a hand into a rack in a state in which a robot having a rotary system executes inexpensive PTP control. .

[Brief description of the drawings]

1 is a front view schematically showing the structure of a robot to which an embodiment of a hand attaching / detaching mechanism according to the present invention is applied; FIG. 2 is a longitudinal sectional view showing the hand attaching / detaching mechanism shown in FIG. 1 in a coupled state. FIG. 3 is a perspective view showing a cylinder body taken out; FIG. 4 is a vertical sectional view showing a ball support cylinder taken out; FIG. 5 is a vertical cross section showing a hand attaching / detaching mechanism in a state where a released state of a holder is defined. FIG. 6A is a cross-sectional view showing the hand attaching / detaching mechanism in a state of being cut along the line AA in FIG. 2; FIG. 6B is a plan view showing the upper surface configuration of the shank body of the hand attaching / detaching mechanism; FIG. 6C is a cross-sectional view showing the hand attaching / detaching mechanism in a state of being cut along the line BB in FIG. 2; FIGS. 7A to 7C are perspective views and front views, respectively, showing the configuration of the holder stand. , And plan view; Fig. 7D shows the insertion state of the shank into the hand stand. FIG. 8 is a front sectional view showing the formation state of the measuring slit formed on the shank body; FIG. 9 is a vertical sectional view showing a state where the holder is completely pulled out from the shank. FIG. 10A and FIG. 10B are front views and bottom views showing an example of a hand mechanism mounted on the robot of this embodiment; FIG. 10C and FIG. 10D are respectively this embodiment. FIG. 11 is a perspective view and a plan view showing another example of the hand mechanism attached to the robot; and FIG. 11 is a view for explaining the problems of the conventional hand exchange method. In the figure, M _{1 to} M ₄ …… Drive motor, PL …… Detachment surface, 10 …… Hand attachment / detachment mechanism, 12 …… Robot, 13 …… Hand exchange station, 14 …… Post, 15 …… Support post, 16 ...... First
Horizontal arm, 17 ... mounting base, 18 ... second horizontal arm, 20 ... vertical arm, 21 ... first drive motor 22 ...
… Second drive motor, 24 …… Third drive motor, 26 ……
4th drive motor, 27 ... cover member, 28 ... robot controller, 28a ... robot side interface circuit, 28b ... main control circuit, 30 ... hand mechanism, 30A ... first hand mechanism (from now on) Hand mechanism to be removed), 30B ... Second hand mechanism (hand mechanism to be attached), 32 ... Connecting cable, 32
a: first air hose, 32b: second air hose, 32
c …… electric cord, 34 …… holder, 36 …… shank, 37
...... Fixed part, 38 ...... Bolt, 40 ...... Cylinder part, 40a ...
... Cylinder body, 40b ... Partition wall, 40c ... First outer flange portion, 40d ... Second outer flange portion, 40e ... Slit, 40f ... Through hole, 42 ... Piston, 42a ... … Piston body, 42b …… Projection part, 44 …… Inner cylinder, 44a …… Inner cylinder body, 44b …… Inner flange part, 44c …… Outer flange part,
44d ... through hole, 46 ... bolt, 48 ... ball support tube, 48a
…… Support tube body, 48b …… Ceiling, 48c …… Insertion hole, 48d
…… Ball support hole, 50 …… Bolt, 52 …… Ball, 54…
... Locking member, 54a ... Outer taper surface, 54b ... Main body part,
54c …… Outer flange part, 56 …… Coil spring, 58
...... Cylinder chamber, 60a; 60b ...... Connection port, 62a ...... First
Connector, 62b ... second connector, 62c ... third connector, 64 ... stay, 66 ... relay board, 68 ... locking sleeve, 68a ... tapered surface, 70 ... bottom position confirmation Sensor, 72 ... Stay, 74a-74i ... Connection hole, 76a-76i ...
Communication room, 78a ~ 78i ...... Connection pipe insertion hole, 80a ~ 80o ......
Connection pins, 82a to 82o ...... Connection rods, 84a to 84o ...... Connection bushes, 86 ...... Shank main body, 86a ...... Through hole, 86b ......
Attaching / detaching member, 86c ... Locking cylinder part, 86d ... Inner flange part,
86e …… Inner taper surface for locking, 86f …… Falling part, 86
g …… Locking groove, 86h …… Outer taper surface, 86i …… Inner taper surface for insertion, 88 …… Bolt, 90 …… Coupling tube, 90a …… Main body part, 90b …… Inner flange part, 92 ... bolt, 94 ...
… Mounting plate, 96 …… Hand stand, 96a …… Rack body, 96b
...... Concave part, 96b ₁ ...... taper opening part, 96b ₂ …… straight line introduction part, 96b ₃ …… semicircle part, 96c …… reinforcing rib, 96d …… ball plunger, 98a to 98i …… connection pipe, 100a ~ 100o ...
… Connecting terminals, 102a to 102d …… Through holes, 104 …… Slits for measurement, 105 …… Rotating positioning member, 105a; 105b …… Tapered surface, 108 …… Spacers, 110a to 110o …… Connecting rods, 112
a to 112i ...... connection port connection hole, 114a to 114i ...... connecting passage, 115a to 115c ...... connection hose, 116a to 116c ...... connection port, 118a: 118b ...... connection line group, 120a; 120b ...... opening, 122a to 122d ... recesses, 124 ... partition plates, 126 ... communication holes.

Claims (1)

(57) [Claims] 1. A first arm and a second arm are provided, and the first arm is provided.
By rotating the second arm and the second arm around the first and second axes, respectively, the hand detachably attached to the tip of the second arm is moved to a predetermined position, and the assembly work of the parts is executed. In the assembly system, the hand replacement method in the assembly system for executing the assembly work while exchanging a plurality of types of hands, wherein the first shaft and the hand attached to the tip of the second arm The second arm around the second axis so that the distance is the same as the distance between the mounting part of the rack on which the hand is to be detached and placed, and the first axis. A first step of rotationally driving, a second step of fixing the second shaft, a step of rotating the first arm around the first axis, and the hand at the tip of the second arm. To the corresponding rack Hand-exchange method characterized in that comprises a third step.