JPH0448592B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention provides a lightweight hand that can softly grip an object, using an elastic contracting body that expands and deforms in the radial direction by sucking and discharging pressurized fluid, and generates a contraction force in the axial direction. It is about the mechanism.

Prior Art and its Problems Today, robotic hands, including prosthetic hands, are becoming increasingly popular. This is because, with the development of control devices and related equipment, it has become possible to mechanize or automate tasks that previously had to be done manually, and there are situations in which humans cannot directly perform tasks such as outer space or nuclear reactors. This is due to the increasing demands caused by the environment.

If such robot hands are classified based on their power source, they can be divided into electric, pneumatic, and hydraulic types. There are also mechanical types, but their scope of use is limited because they can only perform the same movements.

Electric robot hands have a wide range of related equipment, making it easy to configure the system and design the control system, but many use servo motors, making them expensive. Also, since a reduction gear is required,
In addition to being limited in the size of the hand, overload tends to generate heat and there is a risk of flames. Furthermore,
Since it uses electricity, it is impossible to avoid the generation of sparks, and there is a problem that it cannot be used in an explosive atmosphere.

Hydraulic robot hands have the advantage of higher output than electric or pneumatic ones, and can provide both rotary and linear motion. However, the power source occupies a large area, the piping is complicated, and it is expensive.
There is a problem of contamination of the surrounding area due to leakage of hydraulic oil. Furthermore, the problem of heat generation cannot be ignored.

Purpose of the Invention On the other hand, pneumatic robot hands cannot obtain a large operating force, but are highly safe against overload, do not have to worry about heat generation, and are less expensive than the two methods mentioned above. advantageous to The purpose of the robot hand of the present invention is to provide a new robot hand that does not use a pneumatic cylinder, has a lightweight and simple structure, can grip objects softly, and does not lose these advantages of the pneumatic type.

Structure of the Invention In order to achieve this object, the robot hand of the present invention includes finger members connected by a hinge joint, one end of which is connected to the free end of the connected finger member, and a robot hand of the connected finger member. an elastic contractile body whose other end is connected to the fixed end and which expands and deforms in diameter and generates a contractile force in the axial direction when pressurized fluid is introduced from the suction/discharge port; The present invention is characterized by comprising a band member that suppresses expansion and diameter deformation of the elastic contraction body, and elastic means that returns the finger member to the initial position when the pressurized fluid is discharged from the elastic contraction body.

In addition, one end of the gripping member, which is made by arranging and joining the above-mentioned elastic contractile body and an elastic stretchable body that similarly generates a stretching force in the axial direction by introducing pressurized fluid in parallel to each other, is attached to the holding member. The gripping member is connected to the gripping member and pressurized fluid is introduced into the gripping member so that the elastic contracting member is placed inside and can be bent freely.

Example The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a view of the robot hand of the present invention viewed from the palm side. Reference numeral 2 denotes a holding member corresponding to a human palm, and in this embodiment, it has a shape similar to the palm. Reference numeral 4 denotes a finger member, which is made of synthetic resin or metal, and is connected by a hinge joint 6, so that the finger member can freely rotate around the axis of the joint. Furthermore, as part of this hinge joint 6 is shown in FIG. The example includes a coil spring. Preferably, at least one joint end of the finger member 4 is formed into a tube shape and has a built-in coil spring.

An appropriate number of finger members 4 are connected as described above, and one end thereof is hinged to the holding member 2.

Next, an elastic contraction body 8 is arranged along the connected finger members, and one end thereof is connected to the connected finger member end 10 with a pin using an eye or clevis 12 provided at the end of the elastic contraction body 8. do. Similarly, the eye or clevis 12 is used to connect the other end of the elastic contractile body 8 to the holding member 2 with a pin. Here, the elastic contractile body 8 expands in the radial direction by introducing pressurized fluid through the intake/discharge port 14 and generates a contractile force in the axial direction.

This elastic contractile body 8 is fixed to the joint portion of the finger member by a band member 16. Band member 1
The material 6 may be any material as long as it suppresses the expansion and diameter deformation when the elastic contraction body 8 expands and deforms, and may be made of metal, but since it comes into frequent contact with the elastic contraction body, the elastic contraction body is not suitable. I don't like things that damage things. Preferably, a material having lower hardness than the surface layer of the elastic contracting body is used, such as a rubber-like elastic body reinforced with a fiber layer and formed so as to hardly stretch. Of course, it may be made of synthetic resin. The third robot hand configured as described above is
As shown in the figure. Note that the connected finger member end portion 10
can be left as is as shown in the figure, but it is recommended to attach a layer of elastic material (not shown) such as rubber or sponge to the outer periphery to prevent damage to the object when the object is gripped by the Garobot hanger. good.

Next, the operation of the robot hand configured as described above will be explained.

Until pressurized fluid is introduced, the elastic means 7 keep each finger member 4 in its initial position. When the pressurized fluid is introduced into the elastic contractile body 8 through the suction/discharge port 14, the elastic contractile body 8 generates a contractile force in the axial direction. By the way, since the finger member 4 is rotatably connected by the hinge joint 6, the robot hand is bent as shown in FIG. 4 due to this contraction force. Furthermore, since the elastic contractile body 8 is prevented from expanding in diameter at the joint by the band member 16 fixed to the joint, it expands and deforms between the band members as shown in FIG. 4. Therefore, when gripping an object, this expanded portion first comes into contact with the object. The elastic contracting body is made of rubber or a rubber-like elastic material whose outer periphery is reinforced with a braided structure using organic or inorganic high-strength fibers as tensile reinforcement elements, so it will not damage the object. It is soft and can be held easily. In addition, the gripping surface has a non-slip braided structure, so you can grip the object reliably.

Next, for example, when the robot hand carries the object to a desired position, if the pressurized fluid is discharged from the elastic contracting body through the suction/discharge port, the restoring force of the elastic contracting body itself and the elastic means provided at the joint part are combined. The finger member returns to its initial position by the restoring force.

Therefore, as shown in FIG. 1, a robot can have a plurality of connected finger members or five fingers like a human hand, and the degree of bending of each connected finger member or the length of the connected finger members can be changed as appropriate. By using a hand, even an object with an uneven shape can be grasped by wrapping it securely. Of course, it is obvious that a robot hand consisting of one connected finger member may also be used.

FIG. 5 shows another embodiment of the robot hand of the present invention. This example differs from the above-mentioned example,
Instead of relatively rigid finger members connected by hinge joints, the elastic contracting body 8 generates a contraction force in the axial direction by introducing pressurized fluid through the suction/discharge port, and the elastic contraction body 8 generates an expansion force in the axial direction. This is a part of a robot hand in which elastic elongated bodies 18 are arranged parallel to each other in contact with each other, and contact portions 20 are joined.

It should be noted that elements given the same reference numerals as in FIGS. 1 to 4 have the same functions.

Clevis 12 provided at one end of both elastic bodies 8, 18
to connect both elastic bodies to the holding member. If the connection is a bottle connection, when both elastic bodies are deformed, unnecessary force will not be applied to the ends of both elastic bodies, which is convenient.
It is assumed that both elastic bodies 8 and 18 are joined to each other at a contact portion 20. When joining, a suitable adhesive is used over the entire length of the contact portion. However, they may be bonded at appropriate intervals. Band members 16 are provided around the gripping member formed in this manner at appropriate intervals. As mentioned above, the band member 16 may be made of metal as long as it prevents the gripping member from expanding and deforming, but since it frequently comes into contact with the gripping member, it is preferably made of metal. It is made of rubber-like elastic material reinforced with fibers or synthetic resin so that it hardly stretches.

When pressurized fluid is supplied to this gripping member through the suction/discharge port 14, the gripping member is bent with the elastic contracting body 8 inside as shown in FIG. 6 with the joint portion as a neutral plane. This is because the introduction of the pressurized fluid causes the elastic contractile body 8 to generate a contraction force and the elastic stretchable body 18 to generate a stretching force. At this time, the gripping member bends the band member 16 as if it were a joint,
The expanded portion of the elastic contractile body 8 comes into contact with the object to be grasped. If pressurized fluid is further supplied to the gripping members, ie both elastic bodies 8, 18, the gripping members will bend even more and grip the object even more firmly. Moreover, as already mentioned, since the surface of the elastic contracting body has a braided structure, the object can be gripped reliably.

On the contrary, if the pressurized fluid supplied to the gripping member is discharged through the suction/discharge port 14, the gripping member returns to the state shown in FIG. 5 due to the restoring force of both elastic bodies. Of course, it is not necessary to provide the band member 16 around the circumference, but the degree of bending becomes constant, and this is particularly suitable for gripping objects with a large diameter. Therefore, a robot hand equipped with a grasping member formed in this manner performs a grasping motion that is quite similar to the grasping motion performed by a human hand.

This is common to the above two embodiments and is due to the characteristics of the elastic contractile body. That is, the contraction force F in the axial direction generated by the elastic contraction body
The relationship between the shrinkage rate ε in the axial direction and the shrinkage rate F in the axial direction is as shown in FIG.
decreases exponentially. This is because when the contraction rate is small, a large force acts to bend the finger member, and when the contraction rate increases to a certain extent, the contraction force F does not change significantly even if the supply or discharge amount of pressurized fluid is slightly increased or decreased. It means that. Therefore, the gripping work can be performed easily and safely.

In addition, in the embodiment shown in FIG.
and the joint portion of the elastic elongated body 18 is the elastic body 8,1.
Although the elastic bodies 8 and 18 are positioned parallel to the axis of the finger 8, if the elastic bodies 8 and 18 are configured to be wound around each other, rotational movement can be applied to the tip of the finger portion.
In this way, the robot hand of this embodiment can be modified and modified in various ways.

Effects of the Invention As described above, the robot hand of the present invention is configured to utilize the contractile force of an elastic contractile body that expands and deforms when pressurized fluid is introduced, so it can be used with hydraulic cylinders, air cylinders, electric motors, etc. Compared to conventional robot hands, there is less mechanical loss, and since the drive device and the gripping portion are integrally formed, the weight of the robot hand itself can be significantly reduced compared to conventional robot hands. Furthermore, since the gripping portion is highly elastic, the robot hand does not damage the object, and is highly safe as it will not cause injury even if a human touches it accidentally. In addition, if compressed air is used as the pressurized fluid, the robot hand will be highly practical without problems of contamination of the surrounding area or ignition caused by sparks. Moreover, the gripping force can be easily controlled.

[Brief explanation of drawings]

FIG. 1 is an overall plan view showing a preferred embodiment of the robot hand of the present invention, FIG. 2 is a partial perspective view of the robot hand shown in FIG. 1, and FIG. 3 is a partial perspective view of the robot hand shown in FIG. 4 is an explanatory view showing the operation of the finger portion shown in FIG. 3, and FIG. 5 is a plan view showing another preferred embodiment of the robot hand of the present invention. 6 is an explanatory diagram showing the operation of the embodiment shown in FIG. 5, and FIG. 7 is a diagram showing the relationship between the contraction force and contraction rate of the elastic contractile body used in the robot hand of the present invention. . 2... Holding member, 4... Finger member, 6... Joint,
7... Elastic means, 8... Elastic contraction body, 10... Finger portion end, 12... Clevis, 14... Suction/exhaust port, 16...
Band member, 18... Elastic extension body, 20... Contact portion.

Claims (1)

[Scope of Claims] 1 A finger member connected by a hinge joint and having one end connected to a holding member and a pressurized fluid introduced through a suction/discharge port, which expands and deforms in diameter and generates a contractile force in the axial direction. a band member disposed at a joint portion of the wing member to suppress expansion and diameter deformation of the elastic contraction body at the joint portion;
elastic means for returning the finger member to the initial position when the pressurized fluid is discharged from the elastic contracting body, one end of the elastic contracting body is connected to one end of the connected finger member, and the elastic means A robot hand characterized in that the other end of the contracting body is connected to the other end of the connected finger member, and the finger member is bent or returned to the initial position by sucking and discharging the pressurized fluid. 2. The robot hand according to claim 1, wherein the elastic means is a torsion spring disposed on the shaft of the hinge joint. 3. An elastic contracting body that expands and deforms in diameter by introducing pressurized fluid from the suction/discharge port and generates a contraction force in the axial direction, and an elastic stretchable body that generates a stretching force in the axial direction are arranged and joined in parallel with each other. A robot hand, comprising: a gripping member, one end of the gripping member being connected to a holding member, and configured to be bendable with the elastic contracting body inside by sucking and discharging the pressurized fluid into the gripping member. . 4. The robot hand according to claim 3, wherein the gripping member includes a band member disposed around the gripping member at a distance to prevent expansion and deformation of the gripping member.