JPH04244325A - Robot hand - Google Patents

Abstract

PURPOSE:To automatically fit or remove a ring-shaped work which is coupled on the inner periphery of a mating member wider than the work and fastened and fixed by a fastening ring. CONSTITUTION:Part of a grindstone 7 held by chuck claws 35 at the outer diameter is inserted into a grindstone holder 8, then the grindstone 7 is released. The fastening ring 20 and screws 33 are thrust to the grindstone holder 8 side with screw drivers 45, and the screws 33 are fastened after the grindstone 7 is thrust to the depth of the grindstone holder 8. When the grindstone 7 is to be extracted from the grindstone holder 8, the screws 33, fastening ring 20 and grindstone 7 are pinched by auxiliary claws 36 and the screw drivers 45 to extract them.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is fitted onto the inner periphery of a mating member that is wider than the ring-shaped workpiece, and then fixed to the mating member by screwing and fixing the tightening ring to the mating member. The present invention relates to a robot hand that automatically attaches and detaches a ring-shaped workpiece to be held.

0002

2. Description of the Related Art In order to improve the surface roughness and tooth profile accuracy of the tooth surfaces of spur gears and helical gears, finishing of the gears is carried out by grinding. In finishing processing by grinding, for example, the gear to be machined is supported on both sides by the head stock and the tail stock, and the gear to be machined is meshed with an internal gear-shaped grindstone, while the gear to be machined is moved by a spindle motor. The grinding wheels are rotated synchronously by a grinding wheel drive motor, and the gear to be processed and the grinding wheel are rotated as if they were a pair of gears, thereby making it possible to perform grinding by utilizing the sliding contact between the tooth surfaces of the gear to be processed and the grinding wheel. Basic.

FIGS. 5 and 6 are diagrams showing an example of the above-mentioned finishing apparatus, in which a gear to be processed (a helical gear is shown as an example in this embodiment) having a shaft portion S is shown in FIG. One end is supported by the chuck 2 and the head center 3 on the head stock 1 side, and the other end is supported by the tail center 5 on the tail stock 4 side, and is rotationally driven by the main shaft motor 6.

[0004] On the outer periphery of the gear W to be machined, an internal gear-shaped grindstone 7 that meshes with the gear W is disposed so as to be supported by a grindstone holder 8. The grindstone holder 8 is connected to a housing 9 via a bearing 10. It is rotatably supported. Note that the grindstone 7 is restrained by fixing tightening rings 19 and 20 to the grindstone holder 8 with screws 21. The housing 9 is integrally connected to the slide base 11,
Together with the slide base 11, a grindstone head 12 is configured. The grindstone head 12 is connected to a feed motor 13 and a ball screw 1.
4, the feed is applied to move forward and backward.

A chain sprocket 15 is integrally formed on the outer periphery of the grindstone holder 8, while a chain 18 is wound between the chain sprocket 15 on the grindstone holder 8 side and the chain sprocket 17 on the grindstone drive motor 16 side. The grindstone 7 is rotated by a grindstone drive motor 16 via a chain 18.

Therefore, after meshing the gear W to be machined and the grindstone 7, the gear W to be machined is driven by the main shaft motor 6.
By rotating the grinding wheels 7 synchronously with each other by the grinding wheel drive motor 16, the gear to be processed W and the grinding wheel 7 rotate as if they were a pair of gears, and the gear to be processed is rotated due to the sliding contact between the tooth surfaces of the two. A grinding finish is applied to the tooth surface on the W side.

[0007]

[Problem to be Solved by the Invention] In the gear finishing device as described above, the grindstone 7 must be replaced each time the specifications of the gear to be machined change or the grindstone 7 becomes worn. There must be.

[0008] In order to promote full automation of gear machining, there is a strong demand for a system that enables automatic replacement of the grindstone 7.

However, as a special feature of the grindstone 7, when the grindstone 7 is gripped with a chuck or the like and is to be automatically attached and detached from the grindstone holder 8, the inner circumferential surface of the grindstone 7 has a tooth-shaped processed surface. Therefore, it is not preferable to grip the grindstone 7 using the inner diameter chuck method.

On the other hand, if an attempt is made to attach or detach the outer circumferential surface of the whetstone 7 by gripping it with the outer diameter chuck method, the whetstone 7 cannot be taken out from the whetstone holder 8 even though it is possible to attach the whetstone 7 to the whetstone holder 8. In this case, the grindstone 7 cannot be held by a chuck or the like because the grindstone 7 is housed in the center of the grindstone holder 8 which is wider than this.

[0011] For this reason, although the gear machining itself has been able to be performed automatically in the past, the work of replacing the grindstone 7 still has to be done manually by the operator; This has led to a decline in the operating rate of gear processing equipment.

The present invention has been made in view of the above-mentioned problems, and its purpose is to automatically attach and detach a ring-shaped workpiece such as the above-mentioned internal gear-shaped grindstone. The goal is to provide a robot hand that is

[0013]

[Means for Solving the Problems] The present invention provides a robot hand that is attached to the tip of an arm of an industrial robot, and a tightening ring that is fitted onto the inner periphery of a mating member that is wider than a ring-shaped workpiece. This is a robot hand that attaches and detaches a ring-shaped workpiece that is fixedly held on the other side member by screwing and fixing it to the other side member.The robot hand is swingably supported by the hand body and can be opened and closed by the action of a chucking actuator. When detaching the workpiece from the counterpart member, it has an auxiliary claw that comes into contact with one side of the inner side of the workpiece and pushes the workpiece in the detachment direction, while when attaching the workpiece to the counterpart member, it has an auxiliary claw that pushes the workpiece in the detachment direction. A plurality of chuck jaws are installed at the tip of the hand body for chucking using an outer diameter chuck method, and the inner circumferential surface of the mating member is detected prior to mounting the workpiece, and the chuck jaws are attached to the mating member and the workpiece to be mounted thereon. A distance sensor for alignment with the hand body, and a tightening ring formed on the outer periphery of the hand body that is to be screwed and fixed to the mating member when mounting the workpiece are inserted and guide and support the workpiece. When the workpiece is removed, the tightening ring that is pushed out from the other member is inserted into the ring guide surface, and the hand body is provided with a ring guide surface that is rotated by a motor to tighten the multiple screws attached to the tightening ring. A plurality of screwdrivers are rotatably operated, and the screwdrivers are rotatably supported and moved forward and backward in the axial direction of the workpiece by the function of a slide drive means, and when the workpiece is mounted, a part of the workpiece is inserted into the mating member. Afterwards, the chuck jaw waits for the workpiece to be released and then moves forward, pushing the clamping ring and workpiece together with the screw pre-installed in the clamping ring into the mating member using a screwdriver, while assisting when the workpiece is removed. It consists of a screwdriver and a screwdriver holder that holds the workpiece pushed out by the claws by pinching them together with a tightening ring and a screw between the screwdriver and the auxiliary claws.

[0014]

[Function] According to this structure, when mounting the workpiece on the mating member, the hand main body is advanced while centering the mating member and the workpiece using the distance sensor, and the chuck jaws are chucked using the outer diameter chuck method. Insert the kinging workpiece into the mating member. Once a part of the workpiece has been inserted into the mating member, the chuck claw is operated to unchucking, the screwdriver supported by the driver holder is advanced, and the tightening ring supported by the ring guide surface and this tightening are moved forward. Push in the screw attached to the attachment ring together with the workpiece. Thereafter, by rotating the screwdriver, the screw is tightened into the mating member, and the workpiece is fixed to the mating member by the tightening ring.

On the other hand, when taking out the workpiece from the other member, the auxiliary jaws of the chuck jaws passed through the inside of the workpiece are pressed against one side of the inner side of the workpiece. Advance the screwdriver further until its tip lines up with the screw that secures the tightening ring. When the screwdriver is rotated to loosen the screw in this state, the screw, the tightening ring, and the workpiece are placed between the screwdriver and the auxiliary claw due to the pressing force from the driver holder and the auxiliary claw. Being squeezed. Therefore, by retracting the hand main body in this state, the workpiece is separated from the mating member together with the tightening ring.

[0016]

[Example] Figures 1 to 4 are diagrams showing an example of the present invention.
An example of a robot hand for replacing the grindstone of the gear finishing device described above is shown. Note that the upper half and lower half of FIG. 1 show different operating states.

As shown in FIG. 6 as well as FIG. 2, one of the tightening rings 19 that fixes the grindstone 7 to the grindstone holder 8 of the housing 9 remains fixed to the grindstone holder 8, and the screw 33 The other tightening ring 20 is fixed by
The grindstone 7 is automatically replaced by attaching and detaching the grindstone 7 together with the grindstone 7. A robot hand 31 for automatically replacing the grindstone 7 is attached to the tip of an arm of an industrial robot (not shown).

FIGS. 1 and 3 are diagrams showing details of the robot hand 31, in which four grooves 34 are formed radially in the hand body 32, and chuck claws 35 are formed in the grooves 34.
are accommodated in each. The chuck claw 35 has an auxiliary claw 36 integrally formed at one end thereof, has a deformed C-shape as a whole, and is swingably supported by the hand body 32 by a pin 37.

The chuck claw 35 also has a pin 40 and an elongated hole 41 in a plate 39 that moves forward and backward by the action of a chucking actuator (for example, an air cylinder) 38.
This allows the plurality of chuck claws 35 to open and close in unison. Note that one chuck pawl 35 is formed with a protrusion 42 that engages with the tooth groove of the grindstone 7 to index the teeth.

When the grindstone 7 is mounted on the grindstone holder 8, the grindstone 7 is chucked by the chuck claw 35 using an outer circumferential chuck method as shown in the upper half of FIG. When detaching the grindstone 7, the auxiliary pawl 36 is pressed against one side of the inner side of the grindstone 7 to push out the grindstone 7, as shown in the lower half of FIG.

At the tip of the hand body 32, non-contact type distance measuring sensors 43 are provided at three locations on the circumference at equal pitches. These distance measuring sensors 43 each measure the distance to the inner peripheral surface of the grindstone holder 8 before attaching the grindstone 7 to the grindstone holder 8, and perform predetermined calculations based on the measured values. A position correction signal is sent to the control system of the industrial robot to align the centers of the grindstone 7 held by the chuck jaws 35 and the grindstone holder 8 with each other.

A cylindrical ring guide surface 44 is formed on the outer periphery of the hand body 32.
A tightening ring 20 for tightening and fixing the whetstone 7 to the whetstone holder 8 is inserted and serves to guide and support the whetstone 7 in any case when the whetstone 7 is attached or detached.

Further, a plurality (four) of screwdrivers 45 are arranged on the outer periphery of the hand body 32 for rotating the screws 33 that fix the tightening ring 20 to the grindstone holder 8.

As shown in FIG. 4, the screw 33 is inserted into the tightening ring 20 in advance when the grindstone 7 is installed. In addition to the threaded portion 46, the screw 33 has a medium diameter portion 47 that regulates the position of the screw 33 and the tightening ring 20, and a
A locate pin portion 49 that engages with a locate hole 48 on the grindstone holder 8 side is formed to regulate the relative position of the tightening ring 20 and the grindstone holder 8 via the pin 3 . Further, the head of the screw 33 is formed with a square hole-shaped socket portion 50 that engages with a bit portion at the tip of a screwdriver 45, together with a guide chamfered portion 51.

Here, as will be described later, when the screwdriver 45 engaged with the screw 33 is rotated at a normal position, the screw 33 has a spiral action, so that the axis of the screwdriver 45 and the screw 33 is The length of the socket portion 50 is made sufficiently long to allow relative movement in the direction.

A base frame 52 forming a part of the hand body 32 is provided with a driver holder 54 that moves forward and backward by the function of an air cylinder 53 as a slide drive means. A screwdriver 45 is rotatably supported by this driver holder 54 via a bearing 55, and at the same time, the screwdriver 45 is connected to a spline outer 57 supported via a bearing 56.
It is also guided and supported by the connection with the side spline inners 58.

A driven gear 59 is fixed to the screwdriver 45, while a torque control motor 61 having a drive gear 60 is mounted in the center of the base frame 52.
is provided. Drive gear 60 and driven gear 5
Intermediate gears 62, 63, and 64 are interposed between the screwdriver 45 and the intermediate gears 62, 62, and 9.
, 63, 64, and is rotated by a torque control motor 61. As described above, by moving the screwdriver 45 forward and backward by the driver holder 54, a clutch action is performed to connect and disconnect the meshing state between the driven gear 59 and the intermediate gear 64.

Robot hand 31 configured as described above
In this case, when attaching the whetstone 7 to the whetstone holder 8,
As shown in the upper half of FIG. 1, the tightening ring 20 is previously inserted onto the ring guide surface 44, and the chuck claws 35 chuck the grindstone 7 using an outer diameter chuck method. At this time, the protrusion 42 engages with the tooth groove of the grindstone 7 to index the rotational direction of the grindstone 7, and the tightening ring 20 is attached to the upper half of FIG. The screw 33 is not in the position shown in the screwdriver 45.
is engaged with the tip of the protrusion 65, and is on standby at the backward limit position regulated by the protrusion 65. In addition, by chucking the outer periphery of the grindstone 7 with the four chuck claws 35, it serves to correct the deformation of the grindstone 7 into an ellipse.

In this state, the tip of the robot hand 31 is inserted into the inside of the whetstone holder 8, and the robot itself aligns the center of the whetstone 7 with the center of the whetstone holder 8 based on the signal from the range sensor 43. The position of the robot hand 31 is corrected.

Then, when the robot hand 31 continues to move forward and the grindstone 7 is inserted into the grindstone holder 8 to the extent that it does not fall out of the grindstone holder 8, the chuck claw 35 performs an unchucking operation and moves to the position indicated by the imaginary line a. As a result, the chuck claw 35 releases the grindstone 7.

Subsequently, the screwdriver 45 moves forward together with the driver holder 54 due to the expansion operation of the air cylinder 53. As a result, the tightening ring 20 moves forward along the ring guide surface 44, and as shown in FIG. At the same time, the grinding wheel 7 is fitted into the grinding wheel holder 8 by the tightening ring 20.
It is pushed deep inside. Further, as the screw driver 45 moves forward, the driven gear 59 and the intermediate gear 6
4 meshes with each other.

In this state, the plurality of screwdrivers 45 are rotated at the same time by starting the torque control motor 61. As a result, the tightening ring 20 is tightened and fixed by tightening the screw 33, and the grinding wheel 7 is moved to the grinding wheel holder 8.
is firmly fixed and held.

To tighten the screws, first tighten the plurality of screws 33 all at once as described above, and then tighten the screws 33 one by one, using the screwdriver 45 corresponding to the screw 33 to be tightened. Otherwise, as shown in the lower half of FIG. 1, the driven gear 59 and the intermediate gear 64 are disengaged and their rotation is interrupted. Finally, the torque of each screw 33 is checked.

Once the screw 33 has been tightened in this way, the robot hand 31 is pulled out from inside the grindstone 7 while the chuck claw 35 is being operated again to complete the attachment of the grindstone 7.

Next, the procedure for removing the grindstone 7 from the grindstone holder 8 will be explained. As shown in the upper half of FIG. 1, the robot hand 31 is inserted into the inner periphery of the grindstone 7 while the chuck claw 35 is in a chucking motion, and the chuck claw 35 is in an unchucking motion at a predetermined position. to the lower half of the state. In other words, the auxiliary claw 3 is attached to one side of the inner part of the grindstone 7.
6 is pressed, and a part of the ring guide surface 44 is inserted into the inner periphery of the tightening ring 20.

Subsequently, the screwdriver 45 is moved forward together with the driver holder 54 and at the same time is driven to rotate at a low speed. This will cause the screwdriver 4
5 and the socket portion 50 of the screw 33, each screw 33 is rotated and loosened. The threading stroke of the screw 33 at this time is between the screwdriver 45 and the socket part 50.
It is absorbed at the engaging part.

When the screw 33 is completely loosened, the auxiliary claw 3
6 and the screwdriver 45, the screw 33 and the tightening ring 20 are pinched and supported together with the grinding wheel 7 between the auxiliary pawl 36 and the screwdriver 45, as shown in the lower half of FIG. At the same time, the tightening ring 20 is guided and supported by the ring guide surface 44. Therefore, by retracting the robot hand 31 in this state, the grindstone 7 is moved to the grindstone holder 8 together with the tightening ring 20.
depart from.

[0038]

[Effects of the Invention] As described above, according to the present invention, when attaching a ring-shaped workpiece to a mating member, a part of the workpiece chucked by the chuck claw of the outer diameter chuck method is inserted into the mating member. Release the workpiece from the chuck jaw at the top, and use a screwdriver to push the workpiece together with the clamping ring and the screw that fixes this clamping ring into the depths of the mating member. The workpiece, together with the screw and tightening ring, is held between the auxiliary claw pressed against one side of the inner part of the screwdriver and the screwdriver, and then removed.

Therefore, due to reasons such as the fact that the mating member is wider than the workpiece and the fact that chucking with the inner diameter chuck method and the outer diameter chuck method is impossible, conventional methods have been used to For ring-shaped workpieces, which have been difficult to automatically attach and detach during operation, automatic attachment and detachment including screw tightening work can be realized.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram showing one embodiment of a robot hand of the present invention.

FIG. 2 is an exploded perspective view showing the relationship between a robot hand, a tightening ring, a grindstone, and a grindstone holder.

FIG. 3 is an explanatory view of the right side of FIG. 1;

4 is an enlarged view of the main part of FIG. 1, (A) is a cross-sectional view, (
B) is a left side view of (A).

FIG. 5 is a schematic explanatory diagram showing an example of a gear finishing device.

FIG. 6 is a sectional view showing details of the main part of FIG. 5;

[Explanation of symbols]

7... Grinding wheel (work) 8... Grinding wheel holder (opposite member) 20... Tightening ring 31... Robot hand 32... Hand body 33... Screw 35... Chucking claw 36... Auxiliary claw 38... Chucking actuator 43... Distance sensor 44 ...Ring guide surface 45...Screw driver 53...Air cylinder (slide drive means) 54...Driver holder 61...Torque control motor

Claims (1)

[Claims] Claim 1: A robot hand that is attached to the tip of an arm of an industrial robot, which is fitted onto the inner periphery of a mating member that is wider than the ring-shaped workpiece, and then the tightening ring is fixed to the mating member by screwing. This is a robot hand that attaches and detaches a ring-shaped workpiece that is fixedly held on a mating member by rotating the robot hand. When detaching the workpiece, it has an auxiliary claw that comes into contact with one side of the inner side of the workpiece and pushes the workpiece in the detachment direction, while when attaching the workpiece to the other member, the workpiece is chucked using an outer diameter chuck method. A plurality of chuck claws and a chuck provided at the tip of the hand body are used to detect the inner circumferential surface of the mating member prior to mounting the workpiece and to align the mating member and the workpiece to be mounted thereon. A distance measurement sensor and a tightening ring formed on the outer periphery of the hand body and to be screwed and fixed to a mating member when a workpiece is attached are inserted and guided and supported.
When the workpiece is removed, the tightening ring that is pushed out from the other member is inserted into the ring guide surface, and the hand body is provided with a ring guide surface that is rotated by a motor to tighten the multiple screws attached to the tightening ring. A plurality of screwdrivers are rotatably operated, and the screwdrivers are rotatably supported and moved forward and backward in the axial direction of the workpiece by the function of a slide drive means, and when the workpiece is mounted, a part of the workpiece is inserted into the mating member. Afterwards, the chuck jaw waits for the workpiece to be released and then moves forward, pushing the clamping ring and workpiece together with the screw pre-installed in the clamping ring into the mating member using a screwdriver, while assisting when the workpiece is removed. A robot hand characterized in that it is equipped with a driver holder that holds a workpiece pushed out by the claws by pinching them between a screwdriver and an auxiliary claw together with a tightening ring and a screw.