JPH0727100Y2 - Robot hand joint mechanism - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a hand exchange type for an industrial robot used in a factory production line for processing, assembling, carrying, etc. of components (workpieces) for machinery and appliances. The present invention relates to a joint mechanism of a fluid system path for controlling operation of a robot hand.

<Prior Art> So-called industrial robots have become popular for the purpose of streamlining factory production lines, improving safety, and improving quality control. With the recent trend of high-mix low-volume production of industrial robots, there are relatively many robots of the type that can perform various operations by replacing a hand device that holds a workpiece.

Such a robot is generally separable into a machine-side arm extended from the robot body and a hand-side device for gripping a workpiece and performing work such as machining. It is an expression. Then, a plurality of hand devices suitable for various work are stocked around the base of the robot, and the required hand device and the used hand device are automatically They are exchanged for the next work. Therefore, the connecting portion between the machine base side arm and the hand device adopts a structure that is easy for automatic exchange.

The structure of the connecting portion is composed of an integral joint mechanism as a robot hand and a joint mechanism of a signal system and a drive system for operating the hand device.

FIG. 5 and FIG. 6 are schematic explanatory cross-sectional views of a conventional joint part mechanism at the time of separation and connection. The joint portion mechanism in the illustrated example shows the joint portion mechanism of the operation control fluid system path that uses fluid pressure such as air pressure and hydraulic pressure for operation control of the hand.

In the figure, reference numeral 1 is an arm on the machine base side of a robot, and a connecting body 2 which is a connecting member to a later-described hand device is provided at the tip of the arm. 3 is a hand device, which is provided with a hand (not shown) for holding a workpiece on one side,
On the other side, a connection body 4 which is detachable from the connection body 2 is provided.

Therefore, by attaching and detaching the connecting main bodies 2 and 4 of the machine-side arm 1 and the hand device 3, respectively, a robot hand device that can be replaced with the hand device 3 according to a desired workpiece can be obtained. . In this case, the connecting body 2,4
Is to be integrally connected and fixed by a known lock mechanism (not shown), and when the hand device 3 is attached or detached, the connection and fixation are released by an unlocking operation of the lock mechanism.

The connecting body 2 has a shape of a rectangular block or a circular block having a required thickness and having rigidity. Then, mounting holes 2a for press-fitting the sockets 5 of the joint members for circulating the fluid for motion control are formed at appropriate positions. The socket 5 is press-fitted into the mounting hole 2a as a female part of the joint member. This socket 5 is a cylindrical body having a shape in which an inlet portion 5a connected to the hand device 3 is partially expanded in a taper shape, a trumpet shape, or the like, and the opposite side of the connection side is a screw 5b for screwing in a pipe joint 6.
Is engraved. The pipe joint 6 is a machine-side connection terminal of a fluid pipe (not shown) that supplies the operation control fluid of the hand apparatus 3 from the machine side of the robot to the hand of the hand apparatus 3.

The connection body 4 has the same rigidity as the connection body 2. Further, a mounting hole 4a into which the plug 7 as a joint member is press-fitted is formed at a position corresponding to the mounting hole 2a of the connecting body 2. The plug 7 is press-fitted into the mounting hole 4a as a male part to be inserted into the socket 5 of the coupling body 2 which is a joint member. This plug 7 is provided with an insertion shaft portion 7a for inserting into the socket 5, which has a fluid passage 7c formed in the shaft center and an O-ring 8 mounted on the outer periphery of the shaft. This O-ring 8 is inserted into the socket 5
When 7a is inserted, its elastic deformation causes the fluid path of socket 5
It closely adheres to the inner wall of 5c. Therefore, the outer diameter of the insertion shaft portion 7a of the plug 7 is made extremely small with respect to the inner diameter of the fluid passage 5c of the socket 5 so that the O-ring 8 can be elastically deformed. A screw 7b for screwing the pipe joint 9 is engraved on the opposite side of the insertion shaft portion 7a of the plug 7. The pipe joint 9 is a hand device side connection terminal of a fluid pipe (not shown) that supplies the operation control fluid to the hand of the hand device 3.

When connecting the machine-side arm 1 and the hand device 3 having the above-described configurations, several types of replacement hand devices 3 are arranged around the robot machine frame, and the machine-side arm 1 is controlled by the control system. Approach. Then, the hand device 3 is positioned above the hand device 3 to be connected by the identification code or the like printed on the connection body 4 or the like, and is brought close to the connection body 4. Next, the plug 7 of the connecting body 4 and the connecting body 2
Align the socket 5 and insert the shaft 7a into the socket 5.
The fluid path 5c. As a result, the fluid path 5c of the socket 5 and the insertion shaft portion 7a are tightly connected by the elastic deformation of the O-ring 8 to form a fluid system path. The lock mechanism operates almost simultaneously with this connection to integrally connect and fix the connection body 2 and the connection body 4 (see FIG. 6).

Next, when the hand device 3 is replaced, the required clamp device or the like is operated at a predetermined storage position of the hand device 3 to fix the hand device 3, the lock mechanism is released, and the machine base side arm 1 is operated. The connection main body 4 and the connection main body 2 are separated from each other, and then the next hand selection operation similar to the above is performed.

<Problems to be Solved by the Invention> However, the joint mechanism of the fluid path for motion control including the socket 5, the plug 7 and the like has the following problems.

That is, the O-ring 8 is interposed between the socket 5 and the plug 7. Therefore, since the O-ring 8 is pressed against the gap between the socket 5 and the plug 7, a large detaching force is required due to the frictional resistance of the O-ring 8 during the detaching operation. As the number of operation control fluid passages increases, the detaching force also increases accordingly.

Further, when the number of motion control fluid paths increases when the robot hand is caused to perform complicated and multifunctional operations, the number of sockets 5 and plugs 7 that are joint mechanism members also increases.
There may be a problem of misalignment of the axial center position of each socket and plug. The degree of misalignment increases as the number of joints (the number of fluid passages) increases due to manufacturing errors, variations, etc., so that it becomes difficult to concentrically and evenly fit the O-rings, and the operation control fluid This causes a serious problem in the operation of the robot, such as the inability to supply properly.

The present invention is provided to solve the above problems, and reduces the attachment / detachment force of a joint member composed of a socket and a plug, and absorbs a misalignment error due to an increase in the number of joints, thus providing a good connection. The purpose is to obtain a joint mechanism of a robot hand that can realize performance.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a connecting body of the above-mentioned connecting portions of a robot hand for detachably connecting a machine-side arm of a robot and a hand device on the tip side. In the joint part mechanism of the operation control fluid system passage, the socket having the fluid passage formed with the plug insertion hole at one end side is provided in the connecting body of the machine side arm to form the fluid passage communicating with the fluid passage. In addition, a plug provided with an insertion shaft portion to be inserted into the plug insertion hole is provided in the connecting body of the hand device, and O-rings are attached to the inner peripheral wall side of the plug insertion hole and the outer periphery of the insertion shaft portion of the plug, respectively. And a connecting portion formed so that the central diameter of the socket-side O-ring is larger than the central diameter of the plug-side O-ring, and the connecting portions of the both fluid paths are sealed by pressure contact between the both O-rings. It is a mechanism.

<Operation> When the insertion shaft portion of the plug is inserted into the socket, the O-ring of the insertion shaft portion abuts the large-diameter O-ring on the socket side. This contact is a so-called oblique contact since both O-rings have different diameters. Then, when the plug is further pressed, the abutting force presses the socket-side O-ring against the inner peripheral wall of the plug insertion hole and the plug-side O-ring against the outer periphery of the insertion shaft due to the component force of the pressing force. And they are pressed against each other. The other component of the pressing force acts so that the O-ring on the plug side is pushed into the inside of the O-ring on the socket side.

As a result, the two O-rings are brought into surface contact with each other by elastic deformation corresponding to the pressing force, thereby exhibiting a sealing function. In this way, since the O-rings are pressure-contacted to each other for sealing, it is possible to perform the connecting work of the joint portion without requiring a large attaching / detaching operation force.

In addition, even if the number of joints of the socket and the plug is plural and there is a misalignment between the O-rings, if the misalignment is within a range in which the two O-rings can contact each other in the oblique direction, they will not be pressed against each other. Therefore, the sealing function is not affected, and the attachment / detachment operation force does not increase at all.

<Embodiment> A preferred embodiment of the present invention will be described below with reference to the drawings. The difference from the prior art of the present invention is that FIG. Socket press-fitted into the mounting holes 2a, 4a of the connecting body 2, 4 in
It is in the joint part mechanism by the joint member consisting of 50 and the plug 70.

That is, FIG. 1 is a cross-sectional configuration diagram of a main part showing a separated state of the joint mechanism according to the embodiment of the present invention, and FIG. 2 is a cross-sectional configuration diagram of the main part showing a connected state of the joint mechanism. .

In FIG. 1, reference numeral 50 denotes a cylindrical socket, which is one component member of the joint member. The axial center portion of the socket 50 is a fluid path 51 through which a fluid for hand operation control such as air and oil flows.
Is formed so as to penetrate through. A screw 51a is engraved on one end side of the fluid passage 51 to screw the pipe joint 52 therein. On the other end side, a plug passage hole 53 is formed by increasing the diameter of the fluid passage 51 by a length for swallowing an insertion shaft portion of a plug 70 described later. Further, an O-ring groove 53a is formed on the inner peripheral wall near the entrance of the plug insertion hole 53, and an O-ring 54 is engaged and attached.

The socket 50 having such a structure is press-fitted into the mounting hole 2a of the connecting main body 2 (see FIG. 3) provided on the machine base side arm 1 as in the conventional case, and the pipe joint 52 is mounted on the machine base side from the machine base side. A fluid pipe (not shown) for supplying the operation control fluid is connected. The plug insertion hole 53 side of the socket 50 serves as a connection side with the hand device 3 described later.

The plug 70 is a component member on the other side of the joint member. The axial center of the plug 70 is formed by penetrating a fluid passage 71 through which a control fluid for hand operation such as air and oil flows. A screw 71a is engraved on one end side of the fluid passage 71 to screw the pipe joint 72 into the screw. Further, on the other end side, an insertion shaft portion 73 having a required length which is inserted into the plug insertion hole 53 of the socket 50 with a gap is provided in a protruding manner. And again, the axial length intermediate portion of the insertion shaft portion 73,
Preferably, an O-ring groove 73a is formed on the outer periphery of the shaft proximal end portion, and an O-ring 74 is engaged and mounted.

The plug 70 having such a structure is press-fitted into the mounting hole 4a of the connection body 4 (see FIG. 3) provided in the hand device 3,
A fluid pipe (not shown) for supplying an operation control fluid to the hand 31 at the tip is connected to the pipe joint 72. And plug
The side of the insertion shaft portion 73 is connected to the arm 1 on the machine base side.

Therefore, when the hand device 3 and the machine-side arm 1 are connected, the operation control fluid enters the socket 50 from the machine-side through the pipe joint 52, and from the insertion shaft portion 73 of the plug 70 to the pipe joint 72.
And is supplied to the hand 31 on the tip side.

The O-rings 54 and 74 are sealing members that prevent the operation control fluid from leaking out from the connecting portion between the socket 50 and the plug 70, and both O-rings are actuated by the operation described later in the connected state shown in FIG.
The rings 54 and 74 are pressed against each other to exert a sealing function.
In this case, the outer diameter A of the insertion shaft portion 73 of the plug 70 is smaller than the inner diameter d ₁ of the O-ring 54 on the socket 50 side, and the socket 50 is smaller than the outer diameter d ₂ of the other O-ring 74. The inner diameter B of the plug insertion hole 53 is made large so that the insertion shaft portion 73 and the plug insertion hole 53 do not come into contact with each other.

FIG. 4 is an explanatory view of the above-mentioned sealing action of the O-rings 54 and 74 which are sealing members, and FIG. 4A shows the socket 50 and the plug.
70 shows the state of a concentric position, and (b) figure has shown the case of a slight misalignment state.

The rings 54 and 74 have the same ring cross-section thickness in order to exert a sufficient sealing function, and the O of the socket 50 side is
The center diameter D ₂ of the O-ring 74 on the plug 70 side is smaller than the center diameter D ₁ of the ring 54 due to the diameter difference that allows pressure contact when required. This diameter difference sets, for example, the center diameter D ₁ of the O-ring 54 and the outer diameter d ₂ of the O-ring 74 to be the same. In this case, in the concentric state of FIG. Abut.

Therefore, for example, when the machine side arm 1 provided with the socket 50 is positioned with respect to the replacement hand device 3 at a predetermined position and the connection body 2 is opposed to the connection body 4 of the hand device 3, the socket 50 When the plug 70 on the hand device 3 side is located in the concentric state of FIG. 4 (a), when the insertion shaft portion 73 of the plug 70 is inserted into the plug insertion hole 53 of the socket 50,
The O-ring 54 and the O-ring 74 abut each other as shown in the drawing, and press each other. When the pressing force F becomes strong, the O-ring 54, which has the contact portion in the oblique direction, has a component force Fa _{1 of the} pressing force F _1.
To the inner peripheral wall of the plug insertion hole 53 and to the O on the plug 70 side.
The ring 74 is pressed by the reaction force Fa ₂ against the outer peripheral wall of the insertion shaft portion 73 in the pressing direction to elastically deform and press-contact each other. The component force Fb ₁ of the pressing force F is the O-ring 74
, The other O-ring 54 acts so as not to be easily inserted.

Due to such an action, both O-rings 54 and 74 elastically deform in accordance with the pressing force F, are brought into surface contact with each other, and press-contact with each other, thereby exhibiting a sealing function. Socket 50 in this state
Then, the connection of the operation control fluid path of the plug 70, that is, the machine side arm 1 and the hand device 3 is completed.

In the above connecting work, the insertion of the insertion shaft portion 73 into the plug insertion hole 53 can be carried out extremely smoothly without receiving resistance until the O-rings 54 and 74 come into contact with each other. Further, similarly, the extraction at the time of replacement with the hand device 3 is also extremely smooth, and in short, the attachment / detachment operation force of the replacement work can be made extremely light.

Next, if the number of operation control fluid paths is large and the number of joints consisting of socket 50 and plug 70 is large,
The axes of the plug 50 and the plug 70 do not always coincide with each other due to manufacturing errors or the like, which may cause misalignment.

FIG. 4B shows the contact state of the O-rings 54 and 74 in the case of the above-mentioned misalignment.

In the present invention, as described above, when the difference in diameter between the O-rings 54 and 74 is equal to the cross-sectional thickness of the O-ring, the degree of misalignment seals up to about a quarter of the cross-sectional thickness. The performance can be exhibited without impairing the function. That is, the O-ring 74 on the plug 70 side is the O-ring on the socket 50 side.
If it is possible to contact the 54 from the diagonal direction in the entire circumference, it is possible to perform the above-mentioned pressure contact action,
This makes it possible to exert the sealing function without impairing it.

Therefore, if the diameter difference between the O-rings 54 and 74 is set in such a manner that the contact between the O-rings 54 and 74 is in an oblique direction in consideration of manufacturing error, variations, etc., the center diameter D _{1 of the} O-ring 54 is And O-ring
It is not necessary to match the outer diameters d _{2 of} 74. If the central diameter D ₁ of the O-ring 54 is at least larger than the central diameter D ₂ of the O-ring 74, the intended purpose can be sufficiently achieved.

In the above description, the description of the integral connecting mechanism and operation by locking, unlocking, etc. of the connecting main bodies 2 and 4 of the machine base side arm 1 and the hand device 3 as a robot hand is omitted. It is the same as the conventional one.

<Effect of the Invention> As described in detail above, according to the present invention, the seal of the joint portion of the fluid path for motion control when the robot hand is replaced is the O-ring mutual connection provided on the socket and the plug. Since it is carried out by press contacting, it is possible to obtain a sufficient sealing function and it is possible to work with an extremely light operating force when attaching and detaching the joint portion.

Further, even if there is a misalignment between the joint members such as the insertion shaft portion of the socket and the plug, the misalignment can be absorbed and the connection can be made without impairing the sealing function.

Further, since the friction between the O-ring and the insertion shaft portion is eliminated during the attachment / detachment, the durability of the O-ring can be improved, that is, the sealing performance can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram showing a separated state of a joint section mechanism according to an embodiment of the present invention, and FIG. 2 is a sectional configuration diagram showing a connected state of a joint section mechanism according to an embodiment of the present invention. FIG. 4 is a schematic perspective view of a connecting portion of a robot hand, FIGS. 4 (a) and 4 (b) are explanatory views of the sealing action of an O-ring when the joint mechanism is connected, and FIG. 5 is a conventional joint mechanism. FIG. 6 is a sectional configuration diagram of the robot hand connecting portion showing the separated state, and FIG. 6 is a sectional configuration diagram of the robot hand connecting portion showing the connecting state of the conventional joint mechanism. 1 …… Machine stand side arm, 2 …… Connection main unit, 3 …… Hand device, 4
...... Coupling body, 50 ...... Socket, 51 …… Fluid path, 53 …… Plug insertion hole, 54 …… O ring, 70 …… Plug, 71 …… Fluid path, 73 …… Insert shaft part, 74 …… O-ring, D ₁ ... O-ring 54
Center diameter of D _2, ... O ring 74 center diameter.

Claims (1)

[Scope of utility model registration request] 1. A joint mechanism of a fluid path for motion control provided in a connecting body of both connecting portions of a robot hand for detachably connecting a machine-side arm of a robot and a hand device on a tip side, A plug provided with a socket having a fluid passage formed with the end side as a plug insertion hole in the connecting body of the machine side arm, forming a fluid passage communicating with the fluid passage, and providing an insertion shaft portion to be inserted into the plug insertion hole Is provided in the connection body of the hand device, and O-rings are provided on the inner peripheral wall side of the plug insertion hole and the outer periphery of the insertion shaft portion of the plug, respectively, and the center diameter of the O-ring on the socket side is the O-ring on the plug side. A joint part mechanism for a robot hand, characterized in that the joint part mechanism of the robot hand is formed so as to have a diameter larger than the center diameter of the ring and the O-rings are pressed against each other to seal the connecting portion of the both fluid paths.