JPH0660857B2 - Winding type pressure sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrapping type pressure sensor, and more particularly, it is attached to a finger portion of a robot hand having a plurality of finger portions to provide a tactile sensation to the robot hand. The present invention relates to a winding type pressure sensor capable of improving workability of a robot hand.

[Conventional technology]

Conventionally, there has been proposed a distributed pressure sensor which is attached to a robot hand or the like and detects a distribution of a force applied in a direction perpendicular to the hand, using a conductive rubber or plastic as a detection element. Figure 6 shows an example of this.
This is a combination of thin conductive rubber strips 1 and 2 which are perpendicular to each other in two layers. If a force perpendicular to the rubber strip arrangement surface of this pressure sensor is applied, the conductive rubber strips 1,
The area of the contact portion 2 increases and the resistance changes. Therefore, as shown in FIG. 7, for example, a voltage of 5V is applied to the voltage terminal 3 by 10V.
The magnitude of the applied force can be known by measuring the voltage change at the output point 5 while applying it through the 00Ω resistor 4.

However, in such a distributed pressure sensor using conductive rubber, the area of the contact portion does not necessarily change in proportion to the applied force, so the change in the resistance value of the contact portion is not proportional to the force. Since the output is non-linear and the voltage terminal 3, the ground terminal 34, and the output terminal 5 have to be connected to their respective rubber strips, the number of wires increases if the force distribution is to be detected at high density. Will end up.

Further, FIG. 8 shows another example, in which the Hall element 6 is opposed to the magnet 7, and when the vertical force is applied to the sensor head 8, the Hall element 6 is displaced against the spring force of the spring 9, By detecting the change in the magnetic flux density near 6 with the Hall element 6, the magnitude of the applied force is known.

However, with such a distributed pressure sensor, it is difficult to wrap and attach a humanoid robot hand having a plurality of fingers without changing the shape of the fingers.

[Problems to be solved by the invention]

As described above, the distributed pressure sensor of the form shown in FIGS. 6 and 7 has the drawback that the sensor output is not proportional to the force, and the form shown in FIG. It is not suitable to be applied on the fingers.

The present invention focuses on the above-mentioned conventional problems, and based on the distributed pressure sensor proposed by the present inventor to solve the problems (see Japanese Patent Application No. 61-301181), a plurality of human-shaped finger parts are provided. An object of the present invention is to provide a wrapping type pressure sensor that can be specifically manufactured and that can be attached along a cylindrical or similar finger portion of a hand or the like.

[Means for solving problems]

In order to achieve such an object, the present invention makes at least a part of an outer peripheral portion an arcuate surface, and an annular frame that can be fitted into a finger portion of a robot hand, and is attached along the arcuate surface of the frame, A sheet-shaped elastic body whose upper surface is divided into a plurality of rectangular elements by a grid-like cut groove, and a single crystal silicon plate having a semiconductor strain gauge, which is joined to the upper surface of each rectangular element of the elastic body, A flexible printed circuit board electrically connected to a single crystal silicon plate and wound around a frame so as to enclose a plurality of single crystal silicon plates, and a load applied to a finger portion through the single crystal silicon plates is applied to the semiconductor strain. It is characterized in that detection is performed by a change in the electric resistance value of the gauge.

[Action]

According to the present invention, the single crystal silicon plate is held on the surface of the frame portion corresponding to the belly of the finger portion of the robot hand through the elastic sheet, and the flexible printed circuit board is electrically connected to the single crystal silicon plate. Is wrapped around the single crystal silicon plate so as to enclose it, and the ICs and wiring lead-out terminals are arranged on the flexible printed circuit board so that the sensor fits the shape of the finger part where the sensor is attached. Only by providing the frame, the robot hand can be attached along the finger portion of the robot hand having a cylindrical shape or a shape similar thereto, and it is possible to contribute to improving the workability of the robot hand having a humanoid multi-finger.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an outline of a basic configuration of a pressure sensor applied to the present invention, and this example is proposed by the applicant as a distributed pressure sensor disclosed in Japanese Patent Application No. 61-301181. Here, 11 is a fixed substrate, 12 is an elastic body arranged on the fixed substrate 11 and having a relatively small Young's modulus, and the elastic body 12 is provided with cut grooves 12A in a lattice shape. 13 is an elastic body 12
Is a single-crystal silicon plate attached to the upper surface of the substrate, a semiconductor strain gauge (not shown) is formed on the surface thereof, and a plurality of detection elements 14 are constituted by these. Incidentally, 15 is a load applying portion, the single crystal silicon plate 13 is deformed together with the elastic body 12 when a force is applied to the load applying portion 15, the resistance value of the semiconductor strain gauge formed on the single crystal silicon plate 13 is Since it changes, the single crystal silicon plate 13 and the solder electrode 16
By taking out the change in the resistance value through the flexible printed circuit board 17 electrically connected by, the magnitude of the force applied vertically to the single crystal silicon plate 13 can be detected.

FIG. 2 shows an embodiment of the present invention. Here, 21 is the finger portion of the robot hand, and the cross section thereof is circular in this example, but the point is that if the portion corresponding to the belly of the finger portion 21 has a shape close to a circle, its sectional shape is I don't care.
Reference numeral 22 is a frame made of a material having a certain elasticity, such as metal or plastic, so that the finger portion 21 can be fitted into the finger portion 21.
The frame 22 is made to fit easily, and the frame-shaped pressure sensor 24 itself is held by the frame 22. Reference numeral 25 denotes a sheet-shaped elastic body whose upper surface is separated into individual rectangular elements (for carrying a load) 25B by lattice-shaped cut grooves 25A, and is made of plastic having a lower elastic modulus than the frame 22 or It is made of a rubber material and is bonded to the frame 22. That is, by cutting the groove 25A from the upper surface in this manner, the elastic body 25 is easily adapted to the surface of the frame 22, and one element is independently deformed without significantly affecting other elements, Therefore, it is possible to prevent the interference output from being generated in the adjacent elements.

26 is a single crystal silicon plate adhered to the upper surface of each element 25B of the elastic body 25 , the surface of the single crystal silicon plate 26, such as a semiconductor strain gauge and electrodes (not shown) are formed,
When a load P is applied to the single crystal silicon plate 26 via the individual load applying sections 27, the bending is detected as a change in the resistance value of the semiconductor strain gauge, and the pressure sensor corresponding to the tactile sensation of the finger is detected. Can be detected by 24 .

Further, 28 is a flexible printed circuit board provided so as to cover the surface of the above-mentioned single crystal silicon plate 26, and a wiring pattern (not shown) is formed on the flexible printed circuit board 28. Are electrically connected to each other via the solder electrode portion 29. Further, the flexible printed circuit board 28 has a frame as shown in the figure.
It is wound so as to surround the periphery of 22, and an IC circuit 30 for signal switching is attached to the back portion thereof by soldering or the like, and further, a signal wiring 31 taken out from the flexible printed board 28. 3 and the like are provided on the hand side along the finger portion 21 as shown in FIG. 3, so that the above-mentioned change in resistance value can be taken out to the outside through the IC circuit 30 and the signal wiring 31. You can

Next, a procedure for assembling the winding type pressure sensor as described above will be described with reference to FIGS. 4A and 4B.

First, as shown in FIG. 4A, an elastic body 25 having a grid-shaped notch groove 25A is attached to a frame 22 having an inner surface conforming to the finger portion 21 at a portion corresponding to the belly of the finger portion by adhesion. Next, a single crystal silicon plate 26 having a semiconductor strain gauge, electrodes, etc. (not shown) formed thereon is bonded to the surface of each element 25B of the elastic body 25 separated by the cut groove 25A.

Further, as shown in FIG. 4B, a projecting load applying portion 27 attached to the single crystal silicon plate 26 is provided on the flexible printed circuit board.
Inserted into the hole 32 formed in 28, the electrode (not shown) on the single crystal silicon plate 26 and the electrode (not shown) on the flexible printed board 28 are positioned so as to come into contact with each other at opposing positions, and the solder electrode portion 29 is provided. Laser light 33 is irradiated and soldered so that an electrical connection can be obtained between both.

Thereafter, the flexible printed circuit board 28 is adhered along the frame 22, and by soldering the IC circuit 30 and the signal wiring 31 to the portion of the frame 22 corresponding to the back of the finger portion 21,
The wound type pressure sensor as shown in FIG. 2 can be completed.

5A to 5C show the second assembling procedure. First, as shown in FIG. 5A, a single crystal silicon plate 26 having a semiconductor strain gauge, electrodes, etc. (not shown) is attached to the surface thereof. The load applying section 27 is positioned so that it is fitted into the hole 32 formed in the flexible printed board 28, and the solder electrode section 29 is soldered by irradiating the laser beam 33 from the single crystal silicon plate 26 side. .

On the other hand, as shown in FIG. 5B, the elastic body 2 in which the lattice-shaped cut grooves 25A are formed in the portion corresponding to the antinode of the finger portion 21 of the frame 22.
Attach 5 by gluing. Next, as shown in FIG. 5C, the single crystal silicon plate 26 and the flexible printed board 28 shown in FIG. 5A are integrated, and the elastic body 25 is bonded and integrated to the frame 22 respectively. Match and glue between them. Finally, the flexible printed circuit board 28 is adhered along the frame 22, and the IC circuit 30 and the signal wiring 31 are attached to a portion of the frame 22 corresponding to the back of the finger portion 21.
Can be soldered as shown in FIG. 2 to complete the winding type pressure sensor.

〔The invention's effect〕

As described above, according to the present invention, a sheet-like elastic body having a lattice-shaped cut groove on its upper surface is attached to the outer peripheral portion of the portion corresponding to the belly of the finger portion of the frame fitted to the finger portion. , Single crystal silicon is adhered to each surface of the separated elastic body, and the flexible printed circuit board is wound around the frame so as to enclose them, and the flexible printed circuit board is wound on the frame corresponding to the spine of the above-mentioned fingers. Since the IC circuit and signal wiring are attached, the deformation of the single crystal silicon along with the elastic sheet when a force is applied to the part corresponding to the belly of the finger is that the semiconductor strain gauge formed on the surface of the single crystal silicon Can be detected as a change in resistance,
In addition, since it can be easily fitted to the finger portion of the robot hand having a cylindrical shape or a shape similar thereto, it is possible to accurately detect the distribution of the force applied to the finger portion of the hand.

[Brief description of drawings]

FIG. 1 is a sectional view showing a basic form of a pressure sensor to which the present invention is applied, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG. 3 is an upper surface showing FIG. FIGS. 4A and 4B are explanatory views showing an assembly sequence of the present invention, FIGS. 5A, 5B and 5C are explanatory views showing another assembly sequence of the present invention, FIGS. 6 and 7 FIG. 1 is a perspective view showing an example of the basic configuration of a conventional pressure sensor and its circuit configuration, and FIG. 8 is a configuration diagram schematically showing another example of the conventional pressure sensor. 21 ... Finger part, 22 ... Frame, 23 ... Notch, 24 ... Pressure sensor, 25 ... Elastic body, 25A ... Notch groove, 25B ... Element, 26 ... Single crystal silicon plate, 27 ... Load applying part, 28 ... Flexible print Substrate, 29 ... Solder electrode part, 30 ... IC circuit, 31 ... Signal wiring.

Claims (1)

[Claims] 1. At least a part of the outer peripheral portion is an arc surface,
An annular frame that can be fitted into the fingers of a robot hand, and a sheet-like elastic member that is attached along the arc surface of the frame and whose upper surface is divided into a plurality of rectangular elements by lattice-shaped notch grooves. A body, a single crystal silicon plate bonded to the upper surface of each of the rectangular elements of the elastic body and having a semiconductor strain gauge, and electrically connected to the single crystal silicon plate to form a plurality of the single crystal silicon plates. A flexible printed board wound around the frame so as to be encapsulated, and a load applied to the finger through the single crystal silicon plate is detected by a change in electric resistance of the semiconductor strain gauge. Winding type pressure sensor characterized by.