JP3320671B2 - Electric hand - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric hand for opening and closing fingers by an electric motor.

[0002]

2. Description of the Related Art In general, a hand for gripping various parts for processing, transporting, and the like is performed by a pair of fingers that are opened and closed by a pneumatic cylinder via a lever or the like. In the hand having such a structure, in order to open and close the pair of fingers, a mechanism (a lever or the like) for converting the linear operation of the pneumatic cylinder and its piston into the opening and closing operation of the pair of fingers is required. Instead, it requires additional equipment such as an air pipe to the pneumatic cylinder and a directional control valve that controls the supply and discharge of compressed air to and from the pipe, increasing the number of parts that make up the hand itself, and increasing the hand It is difficult to reduce the size of the apparatus, and it is also difficult to reduce the size of the entire apparatus, including ancillary equipment for operating the apparatus.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and its technical problem is to make it possible to make the whole of the apparatus, including the driving equipment, extremely compact. It is to provide an electric hand.
Further, another technical problem of the present invention is to provide an electric hand capable of increasing a position holding force at a moving end of a pair of fingers, that is, an open position and a closed position, and performing stable gripping of an object. It is in. Another technical problem of the present invention is:
The position detecting means for detecting the position of the finger can be used not only for confirming gripping of an object such as a work by the finger, but also for controlling the energization of the electric motor after the gripping. An object of the present invention is to provide an electric hand capable of suppressing current supply to the electric hand.

[0004]

An electric hand according to the present invention for solving the above-mentioned problems comprises an electric motor provided in a hand body, and a cam member fixed to an output shaft of the electric motor.
On the outer surface of the cam member orthogonal to the axis of the output shaft, a pair of substantially semicircular cam grooves are formed slightly in the direction of a straight line connecting the center of the semicircle to the center of rotation of the cam member and both ends of the cam groove. And a pair of cam grooves are provided so as to be arranged point-symmetrically around the rotation center, and are guided by a guide portion provided in a housing that covers the cam member, so that an axis of the output shaft is provided. and a pair of fingers that operate linearly opened and closed in a direction perpendicular, a drive pin which is opened and closed driven fitted in the cam groove is provided, furthermore, position of the finger
Position detecting means for detecting the position.
Means are mounted on and synchronized with said drive pin
And a moving member attached to the moving member.
The contact between the object to be detected and the object to be detected that is
And a position detection sensor for sensing proximity .

In the electric hand having the above-described structure, the electric motor in the hand body is driven to rotate the cam member, so that the driving pins of the pair of fingers respectively fitted in the pair of cam grooves of the cam member. Are spread or pulled together along the cam grooves, whereby the pair of fingers open and close linearly while being guided by the guide portion. In this case, since the rotational movement of the electric motor is converted into the opening and closing movement of the finger by the cam member provided with the cam groove and the drive pin provided on the pair of fingers, the number of parts as a whole can be reduced, and Since these configurations are also very simple, it is very easy to reduce the size of the hand itself. In addition, since the driving source for opening and closing the fingers is an electric motor, there is no need for additional equipment such as an air pipe and a directional control valve for controlling the supply and discharge of compressed air to and from the pipe. Can be formed compactly.

In the present invention, both ends of each of the cam grooves are formed so as to be close to an arc centered on the rotation center of the cam member, and the wedge effect of the drive pin is formed at both ends of the cam grooves. Thereby, the position holding force of the pair of fingers can be increased. As a result, since a large rotational force is not applied to the cam member by the external force acting on the drive pin from the finger near the open position or the closed position, the position holding force is increased at the open position and the closed position of the finger. In addition, the object can be stably gripped.

In the present invention, the position detecting means
Depending on the finger position detected by the step,
The energization of the motor may be controlled.

Such a position detecting means can be effectively used not only for quickly confirming the reliable gripping of the object by the finger by detecting the position of the finger, and for promptly giving the next operation instruction to the electric hand. It can also be used to control the energization of the electric motor after the grip.
In particular, in the above-described electric hand in which the fingers are opened and closed by the electric motor, the energization of the electric motor is quickly released after confirming the grasp of the target object, and the electric motor coil is damaged by excessive heat generation due to prolonged energization. However, it is necessary to prevent the state of energizing the electric motor by controlling the energization of the electric motor by the position detecting means, thereby avoiding a state in which the electric motor has been energized for a long time.
It is possible to prevent the electric motor from being damaged by heat.

[0009]

1 to 3 show a first embodiment of an electric hand according to the present invention. The electric hand according to this embodiment is provided with a hand main body 1A and the hand main body 1A. Electric motor 2, a pair of openable and closable fingers 6, 6 for grasping or releasing an object, and an output shaft 2 a of electric motor 2
A cam member 3A that converts the rotational movement of the electric motor 2 into an opening and closing operation of the fingers 6, 6 and a housing 7A that guides the fingers 6, 6 linearly.

The hand main body 1A has the electric motor 2 inserted and fixed therein, and a concave portion 9A is formed at one end in the axial direction of the motor 2, and the electric motor 2 is provided in the concave portion 9A. The tip of the output shaft 2a of the motor 2 is led out and arranged, and the cam member 3A fixed to the tip of the output shaft 2a is rotatably housed.

The cam member 3A is formed in a circular shape in plan view, and the output shaft 2a is fixed to the center of the cam member 3A.
A pair of substantially semicircular cam grooves 4 is provided on an outer surface orthogonal to the axis of the output shaft 2a. These cam grooves 4,
As shown in FIG. 4, the center of each semicircle is
A slightly deviates in the direction of a straight line L connecting both ends of the cam groove 4 from the rotation center O of A, and the pair of cam grooves 4, 4
Are provided so as to be arranged point-symmetrically around the rotation center O, and both ends of each cam groove 4 are provided with a cam member 3A.
Are formed so as to be close to a circular arc centered on the rotation center O of.

The housing 7A is connected to the hand body 1
A is attached to the opening end side of the concave portion 9A of A to cover the cam member 3A, and the fingers 6, 6 are connected to the output shaft 2a.
Guide portion 8A for guiding in a direction perpendicular to the axis of the groove
So that the fingers 6, 6 are opened and closed linearly.

Driving pins 5 and 5 respectively fitted into the cam grooves 4 are fixedly fitted to the base ends of the pair of fingers 6 and 6, respectively. These drive pins 5, 5
The cam groove 3 is formed by rotating the cam member 3A.
4 to drive the fingers 6 and 6 to open and close. In the case of this embodiment, when the cam member 3A rotates counterclockwise in FIG. 4, the drive pins 5, 5 located on the center side are pushed apart from each other and moved to the peripheral side of the cam member 3A, and the fingers 6, 6 are moved. 6 by performing an opening operation, and conversely, by rotating the cam member 3A clockwise from the open state,
5 are attracted to each other and move to the rotation center side of the cam member 3A, and cause the fingers 6 and 6 to perform the closing operation.

In the electric hand having the above configuration, the electric motor 2 in the hand main body 1A is driven to rotate the cam member 3A, so that the driving pins 5, 5 of the pair of fingers 6, 6 are moved to the cam member 3A. Are driven along the pair of cam grooves 4, 4, and the fingers 6, 6 open and close linearly. In this case, the rotational movement of the electric motor 2 is controlled by a cam member 3A provided with cam grooves 4 and 4 and a pair of drive pins 5 and 5.
Thus, the movement of the fingers 6 and 6 is converted into the opening and closing movements, so that the number of parts as a whole can be reduced, and since these configurations are extremely simple, the hand itself can be very easily miniaturized. Maintenance is easy. In addition, the driving source for opening and closing the fingers 6, 6 is the electric motor 2
By doing so, there is no need for additional equipment such as an air pipe and a directional control valve for controlling the supply and discharge of compressed air to and from the pipe, so that the entire apparatus can be made compact.

Further, the above substantially semicircular cam grooves 4, 4 are
Since both ends are formed so as to be close to an arc centered on the rotation center of the cam member 3A, the positions of the pair of fingers are held at both ends of each cam groove 4 by the wedge effect of the drive pin 5. Due to the increased force, the fingers 6, 6 near the open or closed position
From the cam members 3 by an external force acting on the drive pins 5
A large rotational force is not applied to A, so that the fingers 6, 6 at the open position and the closed position maintain a high-strength position of the fingers 6, 6 and hold the object stably and reliably. be able to. Therefore, not only when the target object is gripped between the fingers 6, 6 but also when the finger 6, 6 is gripped at the inner peripheral edge of the hole provided in the target object by the opening operation of the finger 6, 6, the reliable gripping operation is performed. It is possible to do.

The pair of cam grooves 4, 4 in the cam member 3A is not limited to the shape shown in FIG. 4, and the center of the semicircle of the cam grooves 4, 4 is moved from the rotation center of the cam member 3A to both ends of the cam groove 4. The cam grooves 4 and 4 are slightly deviated in the direction of the connecting straight line, and have different radii of the cam grooves 4 and 4 and a mutual positional relationship within a range where the cam grooves 4 and 4 are arranged point-symmetrically around the rotation center. Can be selected, and the opening width and the closing width of the fingers 6, 6 can be set according to the size of the object to be grasped. Further, the cam member 3A can be detachably fixed to the output shaft 2a of the electric motor 2 so that the opening width and the closing width of the fingers 6 and 6 can be appropriately changed. Furthermore, the guide portion 8A of the housing 7A is not limited to the above-described groove-shaped one, and may have any configuration.

FIGS. 5 to 8 show a second embodiment of the electric hand according to the present invention. The electric hand according to the second embodiment has substantially the same structure as that of the first embodiment described above. A position detecting means for detecting a position is assembled to control driving of the electric motor and the like.
That is, in this embodiment, the hand main body 1 of the first embodiment is used.
A and a housing 7A instead of a hand body 1B containing an electric motor, and attached to the hand body 1B,
A recess 9 for accommodating a cam member 3B for converting the rotation of the output shaft 2a of the electric motor into the opening / closing operation of the fingers 6,6.
B and a square housing 7B having a groove-shaped guide portion 8B for linearly guiding the pair of openable and closable fingers 6, 6.

The distal end of the output shaft 2a of the electric motor is disposed in the recess 9B of the housing 7B.
Within B, a cam member 3B is fixed to the tip of the output shaft 2a. The cam member 3B is formed with cam grooves 4 and 4 similar to those of the first embodiment.
Is inserted. Therefore, when the cam member 3B is rotated by the drive of the electric motor, the fingers 6 and 6 open and close as in the first embodiment. Then, on the axis of the output shaft 2a of the electric motor on the side of the cam member 3B on which the cam groove 4 is provided, that is, the cam member 3B
A columnar projection 11 which constitutes a part of the position detecting means of the finger 6 is provided at the center of rotation of.

The position detecting means, as clearly shown in FIG. 7, is provided on one of the driving pins 5 of the pair of fingers 6, 6.
And a moving member 10 disposed between the cam member 3B and the finger 6. This moving member 1
0 is a base 10a attached to the one drive pin 5;
And a pair of moving guides 10b, 1 extending from the base 10a in parallel so as to sandwich the projection 11 on the cam member 3B.
0b, extending laterally from one of the moving guide portions 10b,
6 is provided integrally with a mounting portion 10c to which the detection target 12 is mounted at the tip.
As shown in the figure, the detection object 12 is formed in a substantially L-shaped bent state along the inner surface of the concave portion 9B of the housing 7B, and the detection object 12 attached to the tip thereof is provided on the outer peripheral surface of the housing 7B. The sensor 13 is arranged to face the mounting groove 15.

The position detecting sensor 13 is formed in an elongated cylindrical shape, and is inserted into an arbitrary position of a mounting groove 15 having a circular cross section provided on the outer peripheral surface of the housing 7B.
The position detecting means is constituted by the sensor 13 and the detection target 12 attached to the moving member 10. In the illustrated embodiment, a permanent magnet is used as the detection target 12, and a magnetic proximity switch that detects the approach of the magnet that is the detection target 12 is used as the position detection sensor 13. The invention is not limited to these, and various objects can be used, such as a metal to which the detection object 12 is supplied with an induced current, and a high-frequency oscillation type proximity sensor as the position detection sensor 13.

The electric hand provided with the position detecting means is
When the pair of fingers 6 and 6 are driven to open and close by driving the electric motor in the same manner as in the first embodiment, the moving member 10 attached to one of the driving pins 5 moves its moving guide portions 10b and 10b. Projection 1 at the center of cam member 3B
1, whereby the moving member 10 is driven in synchronization with the driving direction of the driving pin 5, that is, in the direction of movement of the fingers 6, 6, in synchronization with the driving pin 5, and
The object to be detected 12 provided at 0c is also driven in the same direction.

The object to be detected 12 moves in parallel with the mounting groove 15 along a concave wall provided on an inner peripheral wall surface of a portion opposed to the bottom surface of the mounting groove 15 in the concave portion 9B of the housing 7B. On the other hand, the position detection sensor 13 is provided on the outer peripheral surface of the housing 7B.
2 is installed outside the portion where the object 2 is located, in parallel with the moving direction of the object to be detected 12. The detection sensor 13 detects the approach and outputs it as a signal. Therefore, the position detection sensor 13 is attached so that the signal is output when the finger 6 reaches the gripping position of the object to be gripped, or the signal is output when the finger 6 reaches the release position. By arranging the grooves 15 at required positions, an electric signal can be output at each position, that is, the operation state of the electric hand can be detected.

The output of the position detecting sensor 13 is used to detect the position of the finger 6 and quickly confirm that the finger 6, 6 securely grips an object such as a work, as in the case of known position detecting means in various hands. Although it can be effectively used to promptly give the next operation instruction to the movement control system of the electric hand, since the hand of the present invention is electric, the electric motor to the electric motor after gripping the object is used. It can be used effectively for controlling the energization.

That is, in general, in an electric hand which opens and closes a finger by an electric motor, the energization of the electric motor is quickly released after confirming the grip of the object, and the coil of the electric motor is excessively turned on by a long energization. Although it is necessary to prevent heat generation and damage to the electric motor, the power supply to the electric motor is controlled through the drive control system of the electric hand based on the output of the position detection sensor 13 so that the electric motor can be easily controlled. The power supply to the electric motor is released, and damage to the electric motor due to heat can be prevented.

The configuration and operation of the second embodiment described in detail other than those described above are basically substantially the same as those of the first embodiment, and a description thereof will be omitted.

[0026]

As described above in detail, according to the electric hand of the present invention, the rotational movement of the electric motor is controlled by the opening and closing movement of the finger by the cam member provided with the cam groove and the driving pins provided on the pair of fingers. , The number of components is reduced as a whole, and the structure is very simple, so that the hand itself can be very easily reduced in size. In addition, since the electric motor is used as the driving source for opening and closing the fingers, there is no need for an additional device such as an air pipe or a direction switching valve, so that the entire apparatus can be formed compact.

Further, since both ends of the cam groove are formed so as to be close to an arc centered on the rotation center of the cam member, the two ends of the cam groove are formed at both ends by the wedge effect of the driving pin. Since the position holding force of the finger is increased, a large rotational force is not applied to the cam member by the external force acting on the drive pin from the finger near the open position or the closed position, and therefore, the open position and the closed position of the finger In that position holding power is increased,
An object can be stably gripped. Further, the position detecting means for detecting the position of the finger can be used not only for confirming the gripping of an object such as a workpiece by the finger but also for controlling the energization of the electric motor after the gripping. By suppressing more current than necessary,
The electric hand itself can be operated safely and reliably.

Further, since the moving member constituting the position detecting means in the present invention is incorporated in the inside of the chuck and is not affected by the working environment, erroneous operation due to rusting of the object to be detected or adhesion of magnetic powder, etc. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a side view of a main part of the first embodiment.

FIG. 3 is a plan view of the first embodiment.

FIG. 4 is a plan view showing a cam member according to the first embodiment.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

FIG. 6 is a side sectional view of a main part of the second embodiment.

FIG. 7 is a cross-sectional view showing a mounted state of the moving member of the second embodiment.

FIG. 8 is a main part side view showing a mounted state of the position detection sensor of the second embodiment.

[Explanation of symbols]

 1A, 1B Hand body 2 Electric motor 2a Output shaft 3A, 3B Cam member 4 Cam groove 5 Drive pin 6 Finger 7A, 7B Housing 8A, 8B Guide unit 10 Moving member 12 Detected object 13 Position detecting sensor

Continuation of the front page (72) Inventor Koichiro Kanda 4-2-2 Kinudai, Taniwara-mura, Tsukuba-gun, Ibaraki Pref. SMC Corporation Tsukuba Technical Center Kai-61-96692 (JP, U) JP-A-7-42678 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B25J 15/08

Claims (3)

(57) [Claims] An electric motor is disposed in a hand body, and a cam member is fixed to an output shaft of the electric motor. The center of the semicircle is slightly deviated in the direction of a straight line connecting both ends of the cam groove from the center of rotation of the cam member, and the pair of cam grooves is point-symmetric about the rotation center. And a pair of fingers that are guided by a guide portion provided in a housing that covers the cam member and that linearly open and close in a direction orthogonal to the axis of the output shaft. A drive pin that is inserted and driven to open and close is provided, and furthermore, a position detection for detecting the position of the finger is performed.
Means, and the position detecting means is mounted on the drive pin.
A moving member which is moved in synchronization with the drive pin;
Detected object attached to moving member and assembled to hand body
A position detection sensor for detecting the approach of the object to be detected
Electric hand, characterized in that, with and. 2. The electric hand according to claim 1, wherein both end portions of each of the cam grooves are respectively formed so as to be close to an arc centered on the rotation center of the cam member, and both end portions of the cam groove. The position holding force of the pair of fingers is enhanced by the wedge effect of the drive pin. 3. An electric hand according to claim 1, wherein said finger is detected by said position detecting means.
The energization of the electric motor is controlled according to the position.
of.