JP2636384B2 - Robot hand - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot hand for holding a workpiece, and more particularly to a robot hand that does not require an actuator such as a so-called fluid pressure cylinder for driving the hand portion. It is.

(Prior Art) As shown in FIG. 7, for example, a robot hand having a conventional structure has an intermediate part of a fixed bracket 12 fixed to an arm part 10 of a robot, and the fixed bracket 12 is attached to an end of the fixed bracket 12 which is separated from each other. , Actuator 1 such as a hydraulic cylinder
4.For example, by pivotally supporting a pair of pneumatic cylinders and moving the output shafts of the actuators forward and backward, one end of a pair of clampers 16 each having an intermediate portion pivotally supported by the fixed bracket 12 is pushed down or pushed down, so that the clamper 16 is pushed down. The work 18 is generally held by opening and closing the work 18 and bringing the work 18 into contact with or separating from the work contact portion formed on the fixed bracket 12.

(Problems to be Solved by the Invention) However, in such a conventional structure, since an actuator having a relatively heavy weight is used, an increase in the weight of the entire hand unit cannot be avoided. In addition, since a supply source for supplying a working fluid for driving the actuator and a pipe for supplying and discharging the actuator to and from the actuator are required, there is a problem that the maintenance and the arrangement of the pipe become complicated.

(Means for Achieving the Object) The present invention has been made in view of such a problem, and has a novel robot that can clamp a workpiece without using an actuator that cannot avoid an increase in weight. Its purpose is to provide a hand.

(Means for Achieving the Object) In order to achieve this object, the robot hand of the present invention includes:
A fixed bracket fixed to the arm portion of the robot and having a cam groove formed at each end; a movable bracket disposed substantially parallel to the fixed bracket and having a work contact portion; and an intermediate portion at each end of the movable bracket. Are pivotally supported, one end of which is engaged with the corresponding cam groove of the fixed bracket, and the other end is rotated with the approach of the fixed and movable brackets, and the other end is brought into contact with the work of the movable bracket. At least a pair of clampers which can cooperate with each other, guide means for moving the fixed and movable brackets closer to or away from each other while being parallel to each other, and disposed between the fixed and movable brackets so that the two brackets are separated from each other. An elastic member that presses both brackets, and when the two brackets approach each other against the elastic member, Holding means for holding the movable bracket; a locking member provided on one of the fixed bracket and the movable bracket; and an engaging member provided on the other of the two brackets. While the clamper is maintained at the clamping position by engaging the locking member and the engaging member with each other to maintain the two brackets in a predetermined positional relationship, each other from the predetermined positional relationship of the two brackets Engaging means for allowing the locking member and the engaging member to be disengaged from each other by approaching each other, and allowing the clamper to be opened with the separation of the two brackets by being pressed by the elastic member. I get it.

(Operation) When the arm portion of the robot is pressed down while holding the movable bracket and / or the work by the holding means, the fixed bracket and the movable bracket relatively approach each other against the elastic member disposed therebetween. I do. The two brackets are held in a predetermined positional relationship by the engagement of the engagement member with the engagement member of the engagement means.

At this time, the pair of clampers rotate inward about the respective intermediate portions with the relative approach of the fixed bracket and the movable bracket, so that the other end of each clamper is movable bracket, especially It approaches toward the work contact portion and cooperates with the contact portion to pinch the work.

On the other hand, the movable bracket and / or
Or, while holding the workpiece, further pushing the arm portion of the robot to bring the fixed bracket and the movable bracket closer to each other from a predetermined positional relationship held by the engaging means, the locking member of the engaging means Since the engagement with the engaging member is released, the two brackets return to the initial positional relationship by the elastic restoring force of the elastic member disposed therebetween. In addition, approach and return movement of both brackets,
This is always done in parallel by the guiding means.

As the brackets move away from each other, the respective clampers also pivot outward about the intermediate portions thereof, so that the clampers cooperate with the workpiece contact portions of the movable bracket to clamp the workpiece. The other end also rotates in the direction away from the work contact portion with the rotation movement, and as a result, releases the work.

(Embodiment) The robot hand of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a view showing the robot hand of the present invention in a partial cross section. The components having the same functions as those shown in FIG. 7 are denoted by the same reference numerals.

A fixed bracket 12 having an intermediate portion fixed to the arm portion 10 of the robot has a shape in which both ends are expanded and protruded in a direction away from the arm portion, and the ends of the bracket 12 are extended to those ends. Cam grooves 20 extending substantially parallel to the existing direction are provided.

The movable bracket 22 is almost parallel to the fixed bracket 12.
Place. The movable bracket 22 has a pair of work abutting portions 24 protruding crossing the extending direction thereof and spaced apart from each other. Also, movable bracket
A pivot pin 26 is provided at each of the separated ends of the twelve, and a pair of clampers 16 are pivotally supported at their intermediate portions via the pivot pins.

Each of the clampers 16 has a main body portion 16a orthogonal to each other with its middle portion as an intersection, and a work grip portion 16b projecting from the main body portion and having a shape corresponding to the work contact portion 24 of the movable bracket. This work gripper 16b
A guide pin 28 as a cam follower is attached to an end of the main body portion 16a separated from the fixed bracket 12, and is engaged with a cam groove 20 formed at each end of the fixed bracket 12.

The fixed bracket 12 is formed with a pair of through holes 30 penetrating in the direction of the movable bracket 22 and spaced apart in parallel with each other. One end of each of the through holes 30 is fixed to the movable bracket 22 and separated from each other in parallel. An example of a guide rod 32 as a guide means extending therethrough is inserted,
It is ensured that both brackets 12 and 22 approach or move away from each other in parallel. Reference numeral 12a denotes a bush provided at the opening at both ends of the through-hole 30, and smoothes the relative movement of the guide rod 32 with respect to the fixed bracket 12.

A compression spring 34 as an elastic member is interposed between the fixed bracket 12 and the movable bracket 22 so as to surround a part of the guide rod 32 so that the two brackets 12 and 22 are separated from each other. Pressing.

Further, holding means 36 for holding the movable bracket 22 at a fixed position irrespective of the movement of the fixed bracket 12 are arranged at a holding position of the work 18 and a release position for releasing the work 18. It should be noted here that the holding means 36 only needs to be able to hold the movable bracket 22 irrespective of the movement of the fixed bracket 12, and in this embodiment, is disposed adjacent to the work mounting table 38. Then, a pair of holding rods having free ends substantially in the same plane as a part of the work were formed. However, a holding rod integrally fixed to the work mounting table 38, and a part of the work 18 mounted on the work mounting table 38 can also be used, and various modifications are possible.

On the other hand, when the fixed bracket 12 and the movable bracket 22 take a predetermined positional relationship, an engaging means for maintaining the state in that state.
40 are provided.

As shown in FIG. 2 (a), the engagement means 40 is provided as a locking member having one end inserted into a spring receiving hole 42 formed on a side of the fixed bracket 12 facing the movable bracket 22. It has a stop pin 44.

The locking pin 44 is provided with a flange at a portion located in the accommodation hole 42, and a cam surface 46a is formed along the circumferential direction on an annular end surface of the flange facing the movable bracket 22. .

The height of the cam surface 46a, that is, the dimension of the cam surface 46a in the axial direction of the pin, is clearly shown in FIG.
And a plurality of cam portions which gradually increase along the circumferential direction and return to the initial height at predetermined intervals.

Another cam surface 46b having the same shape as the cam surface 46a is also formed at the tip of the locking pin 44. However, it should be noted that the cam surfaces 46a and 46b
It is formed so as to be shifted. Further, the locking pin 44 is formed with a locking hole 48 spaced apart from the cam surface 46b by a predetermined distance and 180 ° apart from each other in the circumferential direction.

Incidentally, the retaining pin 44 is retained by screwing the retaining ring 50 into the spring receiving hole 42 formed in the fixed bracket 12, but the retaining pin 44 is provided on an annular portion of the retaining ring 50 facing the cam surface 46 a of the retaining pin. Has a cam surface 52 in which a portion having a shape corresponding to the cam surface 46a and flat portions are alternately formed at intervals of about 45 °. The locking pin 44 is constantly pressed outward, that is, in the direction of the movable bracket 22, by a compression spring 54 as an elastic member disposed in the spring receiving hole 42.

On the other hand, the movable bracket 22 is formed with a housing recess 56 extending in the direction in which the locking pin 44 protrudes, and the peripheral wall of the housing recess 56 is spaced 180 ° apart from each other in the circumferential direction. An engagement projection 58 as an engagement member is provided. The engagement projection 58 is urged inward in the radial direction by, for example, a compression spring extending outward in the radial direction of the housing recess, and the locking pin 44 is inserted into the housing recess 56. To allow

At the bottom of the housing recess 56, a cam surface 60 is formed in which a portion facing the tip of the locking pin 44 and having a shape corresponding to the cam surface 46b and flat portions are alternately formed at intervals of about 45 °.
Is formed. It should be noted here that the cam surface 60 has substantially the same shape as the cam surface 52 formed on the annular portion of the retaining ring 50, and is arranged in the same phase.

Next, the operation of the robot hand of the present invention thus configured will be described.

FIG. 3 shows the work placed in advance on the work placement table 38.
FIG. 4 is a diagram showing a state in which the clamp 18 is to be gripped from now on using a clamper 16. An end surface portion of the clamper 16 which comes into contact with the lower surface of the flange portion is provided with a contact plate 66 which is supported via a buffer member 64 made of rubber or a rubber-like elastic body and has excellent wear resistance.

When the robot arm unit 10 is pushed down, the fixed bracket 12 and the movable bracket 22 are integrally lowered, that is, descend in the direction of the work 18, and the work contact part 24 of the movable bracket 22 projects laterally. It contacts the upper surface of the flange portion of the work 18.

Therefore, the downward movement of the movable bracket 22 is restricted by the mounting table 38 and the holding means 36 cooperating therewith.

When the fixing bracket 12 is further pushed down in this state, the locking pin 44 provided on the fixing bracket 12
It is inserted into the accommodation recess 56 provided in the 22, and the engagement projection 58 provided in the accommodation recess engages with the engagement hole 48 provided in the locking pin 44,
The fixed bracket and the movable bracket are maintained in a fixed positional relationship.

The manner in which the locking pin 44 engages with the engaging projection 58 will be described with reference to FIG. For the sake of simplicity, each cam surface is shown to be approximately half, that is, 180 °.

FIG. 4 (a) shows that the fixed bracket 12 is a movable bracket.
By approaching 22, the cam surface 46b provided at the tip of the locking pin 44 provided on the fixed bracket 12 is brought into contact with the cam surface 60 of the protrusion 62 formed on the bottom surface of the housing recess 56 of the movable bracket 22. This shows a state of contact. The locking pin 44
The cam surface 46a formed on the flange is in contact with the cam surface 52 formed on the retaining ring 50.

In this state, when the fixing bracket 12 is further pushed in the direction of the movable bracket by the height S of the cam surface 46a, that is, the length in the axial direction of the locking pin 44, the locking pin 44 Since it is in contact with 62, the spring receiving hole 42
The compression spring 54 disposed therein is compressed and deformed, so that the holding means 36 despite the two brackets being relatively close to each other.
As a result, the movable bracket 22 held at the fixed position occupies the fixed position.

As a result, the cam surface formed on the flange of the locking pin 44
The engagement between 46a and the cam surface 52 formed on the holding ring 50 fixed to the fixed bracket 12 is released. This is shown in FIG. 4 (b).

At this time, the cam surface 46b formed at the tip of the locking pin 44
And the cam surface 60 of the engagement projection 62 formed in the accommodation recess 56 is in an abutting state, but not in an engagement state, so that the compression bracket 54 in the spring accommodation hole 42 of the fixed bracket 12 outwardly moves. The pressed locking pin 44 rotates around its axis.

The amount of rotation is determined by the phase difference between the cam surfaces, but in the present embodiment, the pair of cam surfaces is
Since the phase difference is determined to be 45 °, the locking pin 44 rotates 45 °. This situation is shown in FIGS. 4 (c) and (d).

At this time, the fixed bracket 12 is in the state closest to the movable bracket 22, so that the engagement hole 48 of the locking pin 44 is located below the engagement projection 58 provided in the accommodation recess 56. become.

Then, when the arm unit 10 is pulled up, the fixing bracket
The movable bracket 22 is lifted in a direction away from the movable bracket 22. With this movement, the fourth
As shown in FIG. 7E, the locking pin 44 is also fixed to the fixing bracket.
When the protrusion 62 is lifted by the height S of the cam surface 60 formed on the protrusion 62, the distal end of the locking pin 44 engages with the protrusion 62 of the housing recess 56. Will be solved.

However, since the locking pin 44 is pressed outward by a compression spring 54 provided in the spring receiving hole 42, the locking pin 44
As shown in FIG. 4 (f), the cam surface 46a of the cam surface formed on the holding ring 50 fixed to the fixed bracket 12
The cam surface 46b formed on the tip of the engagement pin 44 contacts the cam surface 60 formed on the protrusion 62.

The amount of rotation of the locking pin 44 depends on the cam surface provided on the pin.
Since 46a is the amount of rotation until it engages with the cam surface 52 provided on the retaining ring 50, the phase difference from those cam surfaces, that is, 45a
It becomes ゜.

At this time, the locking pin 44 rotates substantially 90 ° from the state shown in FIG. 4 (a) to the state shown in FIG. 4 (f). Therefore, the locking pins 44 are 18
Since the engagement projections 58 formed on the inner wall of the accommodation recess engage with the engagement holes 48 disposed apart from each other by 0 °, the fixed bracket 12 and the movable bracket 22 are integrally connected.

By the way, the clamper 16 whose intermediate portion is pivotally supported by the movable bracket 22 rotates as the fixed bracket 12 approaches the movable bracket 22, and cooperates with the work contact portion 24 of the movable bracket 22 to work the workpiece 18. Therefore, the work 18 can be transported to a desired position while being held.

On the other hand, when it is desired to release the work 18, while holding the movable bracket 22, the fixed bracket 12 is pushed in the direction of the movable bracket to bring the fixed bracket 12 and the movable bracket 22 closer to each other, as shown in FIG. The engagement means 40 can be released by the same procedure as described.

Next, another embodiment of the present invention is shown in FIG. The purpose of this embodiment is to clamp various types of works having different shapes and dimensions with one hand, and a fixed bracket 12, a movable bracket 22, and a clamper 16 having dimensions corresponding to the respective works. A plurality of robot hands are arranged in parallel, and each fixed bracket 12
Are connected to each output shaft of the switching cylinder 68.

The connecting cylinder 68 is connected to the arm unit 10 of the robot, and a plurality of appropriate fluid pressure cylinders are arranged in parallel, and the respective cylinders associated with each robot hand are provided with appropriate By supplying and discharging a pressurized fluid supplied from an operation pressure source (not shown) through a supply / discharge pipe 72, the associated robot hand is projected from its storage position, and the clamper of the robot hand is opened and closed. By doing so, various works 18 can be held.

With such a configuration, the switching cylinder 68
However, since there is no need to arrange supply / discharge pipes along a plurality of hand parts, it is easy to manage these pipes and to obtain a robot hand that is easy to maintain and inspect.

FIG. 6 shows another embodiment of the robot hand of the present invention. This embodiment is different from the embodiment shown in FIG. 5 in that a necessary robot hand is selected from a plurality of robot hands.
It can be brought to its projecting position without using a hydraulic cylinder.

The fixed bracket 12 is connected to the hand part 10 of the robot via a connection bracket 74, and the connection bracket 74 is fixed to the fixed bracket 12 and another guide rod 76 extending therethrough penetrates. This ensures that the connecting bracket 74 and the fixed bracket 12 approach or separate in parallel. Further, a compression spring 78 as an elastic member is provided between the brackets 12 and 74, and presses the brackets in a direction away from each other.

Further, on the opposing sides of the connecting bracket 74 and the fixed bracket 12, another engaging means 80 equivalent to the engaging means 40 shown in FIG. 2 is provided.

On the other hand, the fixing bracket 12 is provided with locking portions 82 protruding from both ends thereof, and another holding means 84 is provided corresponding to the locking portions 82. It should be noted here that these holding means 84 are arranged in relation to the fixed brackets 12 corresponding to the individual workpieces.

Therefore, when the work 18 having a certain shape and size is clamped, the arm portion 10 of the robot is pushed down while the movement is regulated by bringing the locking portion 82 of the fixed bracket 12 into contact with the holding means 84. Then, since the connecting bracket 74 approaches in the direction of the fixed bracket 12, the engaging means 80 is released.

Then, the fixed bracket 12 is pushed down in a direction away from the arm unit 10 by the compression spring 78 disposed between the brackets.

Then, the fixed bracket 12 and the movable bracket 22 are
When the arm 10 is pushed down while the movement of the movable bracket 22 is restricted by the holding means 36, the fixed bracket 12 is pushed down via the compression spring 78, and the fixed bracket 12 is released. The engagement means 40 provided in association with the bracket 12 and the movable bracket 22 holds the bracket in a predetermined positional relationship.

During this movement, the clampers 16 whose intermediate portions are pivotally supported by the movable bracket 22 rotate inward each other, and can cooperate with the work contact portion provided on the bracket to pinch the work. it can.

Therefore, according to this embodiment, without using a fluid pressure cylinder, a desired hand can be protruded from its storage position to hold a work, and switching can be performed as in the embodiment shown in FIG. It is possible to make the robot hand lighter than that using a cylinder.

The present invention is not limited to these embodiments. For example, the clamper may be configured to rotate in a direction in which the clampers are separated from each other with the approach of the brackets, and the hollow work may be moved from the inside thereof. It is also possible to use a robot hand that presses and holds.

(Effects of the Invention) As described in detail above, the robot hand of the present invention has a structure in which the clamper is driven as the work holding means by simply pushing the arm of the robot. In this way, since a fluid pressure cylinder for driving the clamper is not required, a lightweight robot hand can be provided.

Moreover, unlike the one using the fluid pressure cylinder, there is no problem of installation and management of piping for supplying the working fluid, and further, there is an advantage that such equipment can be omitted.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view of the robot hand of the present invention holding a workpiece. FIG. 2 (a) is an enlarged view of an engagement means suitable for the robot hand shown in FIG. 2 (b) is a perspective view showing a locking pin of the engagement means shown in FIG. 2 (a), FIG. 3 is a view showing the robot hand shown in FIG. 1 in a released state, 4 (a) to 4 (f) are views showing the operation of the engagement means shown in FIG. 2, FIG. 5 is a perspective view showing another embodiment of the robot hand of the present invention, FIG. 6 is a view showing another embodiment of the robot hand of the present invention, and FIG. 7 is a view showing a conventional robot hand. 10… Arm, 12… Fixed bracket 14 …… Actuator, 16… Clamper 16a …… Main body, 18… Work 20… Cam groove, 22… Movable bracket 24… Work contact part, 26 … Pivot pins 28… Guide pins, 30… Through holes 32,76… Guide rods, 34,54,78… Compression springs 36,84… Retaining means, 38… Work table 40,80 … Engaging means, 42 spring receiving hole 44 locking pin 46a, 46b, 52, 60 cam surface, 48 locking hole 50 retaining ring 56 receiving recess 58 Engagement projection, 62 Projection part 64 Buffer member 66 Contact plate 68 Switching cylinder 70 Control means 72 Supply / discharge pipe 74 Connection bracket 82 Locking part

Claims (1)

(57) [Claims] 1. A fixed bracket (12) fixed to an arm (10) of a robot and having a cam groove formed at each end thereof; and a movable bracket (11) disposed substantially parallel to the fixed bracket and having a workpiece contact portion. 22), an intermediate portion is pivotally supported at each end of the movable bracket, and one end is engaged with a corresponding cam groove of the fixed bracket, and is rotated with the approach of the fixed and movable bracket. At least one pair of clampers (16) that can move and have the other end cooperating with a work contact portion of the movable bracket; and guide means (32) for moving the fixed and movable brackets closer to or away from each other while being parallel to each other. An elastic member (34) disposed between the fixed and movable brackets and pressing the two brackets so as to separate the two brackets from each other; A holding means (36) for holding the movable bracket when the two brackets are brought closer to each other; a locking member (44) provided on one of the fixed bracket and the movable bracket; and a holding member (44) provided on the other of the two brackets. Holding the two brackets in a predetermined positional relationship by engaging the locking member (44) and the engaging member (58) with each other by approaching the two brackets to each other. While the clamper is maintained at the clamping position, the engagement between the locking member (44) and the engaging member (58) is released by the two brackets approaching each other from the predetermined positional relationship, and A engagement means (40) for permitting release of the clamper when the two brackets are separated by being pressed by an elastic member. hand.