JPH0321316B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a manipulator applied to industrial robots and the like, and particularly to a manipulator suitable for detecting the magnitude of gripping force of an object to be gripped.

Conventionally, manipulators used in industrial robots, etc., have a fixed weight or shape of the object to be handled, so even if the operator is not aware of the gripping force, there is no problem in terms of logistics. It had not occurred.

However, recently, even in this field, it has become possible to handle a wide variety of objects in small quantities, and selecting a manipulator after recognizing the weight or shape of the object has become a step in logistics work. preparation,
This is becoming more desirable in terms of work efficiency.

However, in conventional manipulators, the gripping force of an object to be grasped is not known even when the object is gripped, so that the object to be grasped is sometimes missed, and the manipulator does not necessarily exhibit desirable working efficiency.

As an emergency measure to resolve this problem, for example, a strain gauge may be attached to the fingers of the gripping mechanism.
There are ways to know how much gripping force is acting on the grasped object on the fingers, but the detection accuracy is quite poor and the detection range is narrow, so the expected results have not been achieved. do not have. In addition, some fingers have a notch shape that directly shows the gripping force of the object to be handled, assuming that the object to be handled is relatively light. When the number of grips increased, the gripping force became insufficient and the gripping force often fell off.

As described above, this problem arises because conventional manipulators uniformly handle the weight of the object to be gripped, and it is desired that a technology that can detect the gripping force at a glance be developed.

This invention was made with practical convenience in mind, and allows the magnitude of the gripping force on the object to be grasped to be detected at a glance, expanding the scope of application of the object to be handled, and further improving the gripping force than before. The purpose of the present invention is to provide a manipulator that achieves high logistics work efficiency.

As a means for achieving such an object, the present invention provides a finger section that applies a gripping force from a gripping mechanism to an object to be grasped via a link, and a finger section that is rotatably connected with a pin to the finger section to apply a grasping force from a grasping mechanism to a grasped object with a relatively small gripping force. A lever for gripping an object; a first strain gauge attached to a leaf spring pressed by one end of the lever to detect the gripping force of the object gripped by the lever; The device is characterized in that a second strain gauge is attached to the finger portion to detect a relatively large gripping force generated when the finger portion is gripped together with the lever.

According to the above configuration, a relatively lightweight object to be gripped is gripped by a lever, the gripping force at that time is detected by the first strain gauge, and a relatively heavy object to be gripped is gripped by the lever and the fingers. Since the gripping force at that time is detected by the second strain gauge, it is possible to widen the scope of handling, such as the size and weight of the gripped object. Furthermore, since the first and second strain gauges are used to detect the size and weight of the object to be handled, there is no chance of the object being grasped and dropped, contributing to improved work efficiency in terms of logistics.

Embodiments of the manipulator according to the present invention will be described below with reference to the drawings.

Figure 1 is a schematic diagram of a manipulator applied to industrial robots, etc., and this manipulator has arm 1.
It has a relatively simple configuration including a gripping mechanism 2 and a gripping mechanism 2. As shown in FIGS. 2 and 3, this gripping mechanism 2 is provided with finger portions 3, 3 that can be moved to expand and contract via links. At the tips of the fingers 3, 3, levers 5, 5 are provided which are connected by pins 4, 4 and are rotatable and movable beyond the inner ridge lines of the fingers 3, 3. The gripping portions of the levers 5, 5 are formed in the illustrated shape with rich undulations so that the object to be gripped will not fall off. Further, the other ends of the levers 5, 5 are supported by springs 6 interposed in push screws 7 provided on the fingers 3, 3, so that elastic movement is given to the levers 5, 5. Further, the other ends of the levers 5, 5 are provided with leaf springs 8, 8 that apply a pressing force when they move elastically.
3, and first strain gauges 9, 9 are attached to the leaf springs 8, 8. Furthermore, the finger portion 3,
Second strain gauges 10, 10 are attached to other parts of 3.

In such a configuration, the levers 5, 5 are in charge of gripping a relatively lightweight object. That is,
Since the object to be grasped is relatively light, the rotational movement of the levers 5, 5 using the pins 4, 4 as fulcrums is also small. , 8, and this pressing force causes the first
The strain gauges 9, 9 detect the gripping force of the levers 5, 5 on the object to be gripped.

On the other hand, when the object to be gripped has a relatively high weight, the rotational movement of the levers 5, 5 using the pins 4, 4 as fulcrums is also high. Therefore, the gripping portions of the levers 5, 5 move from the illustrated position to the position extended by the broken line, so that the levers 5, 5 and the finger portions 3, 3 are responsible for gripping the object. In this case, the gripping force of the object to be gripped is determined by the first strain gauges 9, 9.
It is also detected by the second strain gauges 10, 10. Note that the first and second strain gauges 9, 9, 1
0 and 10 are used with different gripping force range widths.

As described above, the manipulator according to the present invention is configured such that the levers 5, 5 and the finger portions 3, 3 can be used selectively depending on the size of the gripping force of the object to be gripped, so that the applicable width of the object to be handled can be changed. There is no need to worry about the object being grasped or falling off, and the work efficiency is increased.

FIG. 4 shows the second manipulator according to the present invention.
This shows an example, and the above-mentioned first embodiment differs from the finger portion 3,
The difference is that a gripping force detection device 11, for example, carbon fiber or a semiconductor, is attached to No. 3. Although the second embodiment increases the sensitivity of the gripping force of the object to be grasped, it has the same functions and effects as the first embodiment.

From the above explanation, in this invention, objects to be gripped with a relatively small gripping force are held by the lever, and objects to be gripped with a relatively large gripping force are held by the fingers in cooperation with the lever. Since the magnitude of the force is differentiated using the first and second strain gauges, the structure is simplified and the gripping force can be detected with high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic external view showing an example of a manipulator according to the present invention, FIG. 2 is a partially cutaway enlarged view showing an outline of its gripping mechanism, and FIG. 3 is an A--
FIG. 4 is a front view seen from the direction of arrow A, and a partially cutaway enlarged view showing another embodiment of FIG. 2. 1... Arm, 2... Gripping mechanism, 3... Finger section,
4...pin, 5...lever, 6...spring, 7...press screw, 8...plate spring, 9...first strain gauge, 10
...Second strain gauge.

Claims (1)

[Claims] 1. A finger portion that applies a gripping force from a gripping mechanism to an object through a link, a lever that is rotatably pin-coupled to this finger portion and grips an object with a relatively small gripping force, and a lever that A first strain gauge is attached to a leaf spring pressed by one end and detects the gripping force of the object gripped by the lever, and when the object is gripped by the fingers as well as the lever. A manipulator characterized in that a second strain gauge is attached to the finger portion to detect a relatively large gripping force generated in the manipulator.