JPS60164230A - Force converter - Google Patents

Abstract

PURPOSE:To measure applying force in a broad range highly accurately, by using a transmitting body, which converts the applied force into the second force in nonlinear relation and transmits the force to a pressure sensitive element, and arranging a plurality of force converters in an array pattern. CONSTITUTION:When a first force 1 to be measured is applied to a diaphragm 71, the diaphragm 71 is deformed, and the second force is applied to a pressure sensitive element 6 through fluids 30 and 36. When the force 1 is small, the force 1 is proportional to the second force. When the force 1 is increased, the diaphragm 71 is contacted with a diaphragm 92. Thereafter, the relationship between the two forces becomes the difference obtained by subtracting the force yielded by the diaphragm 92 from the relationship before the contact of the diaphragms 71 and 92.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application 2 The present invention relates to force transducers, and more particularly to configurations of force transducers that operate over a wide force range.

(Prior Art and its Problems) Recently, with the rapid development in the field of industrial robots, remarkable progress has been made in robot perception technology such as tactile sense. This is supported by the rapid development of sensor device technology using semiconductors such as silicon, as well as inorganic and organic materials, and attempts are being made to apply this technology to tactile sensors. Hereinafter, a conventional example of a force transducer used for detecting pressure sensation and force sensation will be explained with reference to the drawings.

FIG. 1 shows the configuration of a conventional force transducer. The force transducer is constructed by inserting a conductive rubber 3, forming electrodes 2 on both sides thereof by adhesion or vapor deposition, and adhering this to a pedestal 4.

When force (or pressure) 1 acts on the force transducer,
Pressure is applied to the conductive rubber, and as a result, the resistance value at both ends of the conductive rubber changes. Therefore, the force (or pressure) applied to the force transducer can be detected by extracting the resistance value to the outside via the electrode 2 and measuring it using a well-known detection means. can.

FIG. 2 shows the characteristics of the force transducer when the horizontal axis K represents the applied force and the vertical axis represents the absolute value of the change in resistance value. As shown in the figure, there is a proportional relationship between the applied force and the amount of change in the resistance value, and it is possible to detect the applied force in relation to the resistance value using a well-known detection means.

However, in a force transducer with a conventional configuration,
The detectable applied force is strictly limited to a narrow range,
For this reason, the range of application was limited.

For this purpose, a force transducer that corresponds to the magnitude of the force to be detected is selected in advance from among multiple force transducers and attached to the detection location, and multiple force transducers are sequentially installed according to the force to be detected. This necessitated the use of complex switching detection means. As a result, conventional force transducers have disadvantages such as increased cost and poor operability.

(Objective of the Invention) An object of the present invention is to provide a configuration of a force transducer that eliminates such conventional drawbacks and makes it possible to detect applied forces over a wide range.

(Structure of the invention) According to the invention, a pressure receiving part receives a first force.

The second force is provided with a transmitter that processes the first force into a second force and transmits it to the pressure sensitive element and the second force, and the pressure sensitive element that converts the second force into an electrical signal. has a non-linear relationship with the first force, a pressure receiving part that receives the first force, and a pressure sensing unit that processes the first force into a second force It is characterized by comprising a transmitter that mediates the element, and the pressure-sensitive element that converts the second force into an electrical signal, and the second force has a nonlinear relationship with the first force. The force transducer is characterized in that a plurality of the force transducers are arranged in an array.

(Example) The present invention will be described below with reference to drawings showing examples.

FIG. 3 is a diagram conceptually showing a cross section of an embodiment of the present invention. In the figure, the same numbers as in FIG. 1 indicate the same components. The first force 1 applied to the pressure receiving part 31 is processed into a second force via a transmitting body 5 having the configuration described below, and applies force to a pressure sensitive element 6 such as conductive rubber. The transmitting body 5 includes a connecting shaft 39.38 that connects the presser plate 38, 38 having a circular cross-sectional shape or the like and the pressure receiving portion 31, and transmits the first force applied to the pressure receiving portion 31 to the 38. Spring A32 and 833 with different spring constants placed in contact with said 38, said 3
3 and a stop plate 34 having a passage hole 35, and a cap 37 whose inner wall contacts said 38. Further, the inner chamber 30.36 is filled with a fluid such as gas or liquid. It should be noted that the passage hole 35 may be provided one or several times, as long as it connects the inner chambers 30 and 36, and the number and position thereof are not limited at all.

For example, it may be provided on the side wall of the cap.

Springs with different spring constants can be created by changing the material, wire diameter, outer diameter, winding density, etc. On the other hand, electrodes 2 are attached to both sides of the pressure-sensitive element, and the applied force is detected by processing the electric signal responded by the electrode 6 via external means (not shown). . 4 is a pedestal which, together with the above-mentioned 37, seals the force transducer of the present invention. In the force transducer having such a configuration, the first force applied to the pressure-receiving section is processed into a second force by the transmitter through the following steps, and the second force acts on the pressure-sensitive element. That is, the first force l is applied to the pressure receiving part 31, and the force 32.33 is applied via the pressure receiving part 39.38.
, and deforms it (that is, shrinks or expands it) to generate an inner part at the corresponding 32.33. At the same time, in the system of the transmitter.

A new force is generated due to changes in the volume of the fluid filling the inner chamber 30, deformation of the 6, etc., but the magnitude of the nuclear force (force 20) is the same as the first force and the 32 or 33. The difference between the internal force and the internal force generated at is I'! Almost equal. The second force generated in the fluid 30 is transmitted to the entire fluid 36 via the fluid 35, and eventually pressurizes the pressure sensitive element with the magnitude of the second force (the force is (balanced with the force of deformation in 6 above). At this time, since the inward magnitude generated at 32.33 has a nonlinear relationship with the first force (in the configuration of the present invention), the second force also has a nonlinear relationship with the -th force. This is a non-#il type relationship. The above is illustrated in FIG.

In the figure, the 10th force (indicated as applied force in the figure) is taken as the horizontal axis, the 20th force (indicated as effective force in the figure) is taken as the vertical axis, and the 3rd force is taken as the vertical axis. The relationship between the first force and the second force when 33 in the figure is not present (that is, when the spring is composed of only 32) is 0), and when 32 in the figure is not present (
←) shows the relationship when only 33 exists), and (c) shows the relationship when the configuration of the present invention is adopted (there is a partner of 32 and 33). In the configuration of FIG. 3, an example is shown in which the spring constant of 32 is larger than the spring constant of 33, but the order of the 32 and 33 may be reversed. As shown in Figure 4 (a), when only springs with a large spring constant are used, most of the first force is spent on the internal force of the spring, and the second force acting on the pressure-sensitive element is The force is small compared to the first force.

On the other hand, in the case ←) in the same figure, only springs with small spring constants are used, so most of the 10th force has a magnitude that matches the 42nd force by about 9.

Further, in the figure, in region I, the spring in (b) follows Hooke's law, in region (2), the spring deviates from Hooke's law, and in region (2), the spring reaches saturation. As above.

In the case of (a), the applied force is applied over a wide range.

Although it is possible to use such a force transducer, the disadvantage is that the resolution of the applied force is poor and the output is small, especially when the applied force is small. On the other hand, in case (b), it is possible to obtain sufficient output even when the applied force is small, and the resolution of the applied force is excellent, etc., but on the other hand, the force conversion for large applied forces is The disadvantage is that you cannot use the equipment. 0) above.

←), in the case of (c) of the present invention, the above (a)
The advantages of ← and ←) are combined to have the advantage that the force transducer can be used over a wide range of cases where the applied force is small and large. In addition, in the area of ■ in Figure 4, the first force and the second force are not proportional, so either appropriate approximation or other processing is performed using a signal processing means, or in the area of II. Although measures such as prohibiting the use of the force transducer are required, the effectiveness of the present invention is still as great as before.

FIG. 5 shows another embodiment different from the shape of the spring described above. 5
1 is a spring formed by continuously changing the number of turns per unit length. The spring in question is the previous one! 1iJ3 figure 3
FIG. 6 shows the relationship between the first force and the second force when the spring of 2.33 is used instead. The vertical and horizontal axes in the same figure are the 4th axis.
Same as the figure. In this way, when a spring having the configuration shown in FIG. 5 is used as a part of the transmitting body, there is an origin point at which the figure showing the relationship between the first force and the second force is a smooth curve. be. Note that the shape of the curve can be freely set by changing the 510 winding density.

Section 7.8. and FIG. 9 are diagrams showing another embodiment of the present invention. In the figure, the same numbers as in FIG. 3 indicate the same components. In FIG. 7, reference numeral 71 constitutes a pressure receiving part f, which is a thin metal plate 9 and a diaphragm made of elastic rubber or the like, and deforms (compresses and expands) elastic bodies 72 and 73 in accordance with the first force 1. The elastic bodies 72 and 73 have different compression ratios and play the same role as the elastic bodies 32 and 33 having different spring constants in FIG. 3, respectively. Also, the side wall 7
4 may be configured integrally with the stop plate 34 to prevent the fluid filling the inner chamber 36 from leaking to the outside world.

FIG. 8 shows a force transducer of the present invention characterized in that an elastic body 81 whose wall thickness changes smoothly is used in place of the parts 32 and 33 in FIG. Even in this case, it is possible to provide the same characteristics as in the case where the spring 51 gold shown in FIG. 5 is used.

FIG. 9 shows two diaphragms 71. The force transducer of the present invention is characterized in that it is constructed using the following elements.

91 is a side wall separating the diaphragms 71 and 92. When a force 1 is applied to the force transducer in the figure, the diaphragm 71 deforms and generates a second force on the pressure sensitive element 6 via the fluid filling the 30.36. When the first force is small, the second force and the -th force are proportional.

However, when the -th force increases, it promotes a large deformation of the 71, and the 71 finally comes into contact with the 92, and from then on, the 71
and 92 begin to transform as one. In such a case,
The relationship between the first force and the second force is obtained by subtracting the magnitude of the force generated at 92 from the previous relationship (direct proportionality). FIG. 10 shows the characteristics. The vertical and horizontal axes in this figure are the same as in FIG. 4 above. (a) in the diagram is
71 above alone constitutes 4i' (i.e. Njtl 92
←) shows the characteristics of the force transducer having the configuration of the present invention (Fig. U39).

Further, in the area 1 in the figure, only the corresponding 71 corresponds to the corresponding one, and in the area 2, both the corresponding 7] and 92 gradually correspond to each other as they deform.

In this example, the area of the diaphragm.

By changing the thickness, material 9, etc., or the distance between the two diaphragms, etc., it is possible to change the size of the area 1 in FIG. 10, the slope of ←), etc. Another advantage is that it is also possible to delete the area i (in FIG. 4).

FIG. 11 is a diagram showing another embodiment of the present invention. In the figure, the same numbers as in FIG. 9 indicate the same components. The force transducer of the present invention is characterized in that the embodiment shown in FIG. 9 is arranged one-dimensionally or two-dimensionally in an array. In the same figure.

Although the force transducer according to the embodiment shown in FIG. If necessary, a plurality or types of force transducers each having a configuration including a linear transmitting body may be arranged. In this embodiment, it is possible to detect force (or pressure) distributed over a wide range, slippage 1, etc., and a pressure sensor can be realized with axial accuracy.

The present invention has been described above in detail with reference to examples. In addition, Sections 3.5, 7. and, in the embodiment shown in Figure 8, a spring which is a component of the transmitter.

In an elastic body such as rubber, a phenomenon is utilized in which the displacement occurring in the relevant part saturates with respect to an increase in load, and as a result, the overall elastic constant increases. On the other hand, the previous embodiments shown in FIGS. 9-11 utilize the fact that as the load increases, the diaphragms overlap and the rigidity of the diaphragms increases. In addition to the conductive rubber, the pressure-sensitive element may include a pressure-sensitive semi-electric material, a piezoelectric element, a strain gauge, an adhesive type pressure sensor, a pressure-sensitive organic material, a silicon diaphragm type pressure sensor, and a semiconductor such as silicon. A piezo F having a well-known structure in which a piezoelectric material made of an inorganic, organic, or hybrid material is provided in the gate region of a field effect transistor.
Configuration using ET, etc., spring.

A structure of a transmitting body formed by stacking multiple layers of elastic bodies such as a diaphragm and 91% rubber, a structure of a transmitting body made of a material other than the above-mentioned elastic body having non-linear characteristics, and various types that apply force to the pressure-sensitive element. configuration, well-known techniques for processing electrical signals,
etc. are also within the scope of the present invention.

Furthermore, the properties of the force transducer of the above embodiments depend on the mechanical material constants of the combined fc+s components, such as spring constant, compressibility, stiffness of the diaphragm, etc. Therefore, it is preferable to perform an optimal design by changing the above configuration, material constants 9, etc. according to specifications such as the range of force to be detected, resolution 1, etc. Also,
The invention also includes the use of well-known techniques to compensate for the effects of thermal expansion of fluids etc. filling the interior chamber.

(Effects of the Invention) As described above, according to the present invention, the power can be applied over a wide range including a relatively large force, with a small force as a starting point.

It becomes possible to provide a force transducer capable of emitting nuclear force (or pressure).The dramatic improvement in characteristics achieved by the present invention will significantly contribute to the development of tactile control technology, and its effects will be It's big.

[Brief explanation of drawings]

FIG. 1 shows a conventional force transducer, and FIG. 2 shows a custom-made version thereof. FIG. 3 shows the configuration of the force transducer of the present invention, and FIG. 4 shows its characteristics. FIG. 5 shows a modification of the present invention, and its characteristics are shown in FIG. 6. FIG. 7.8.9 shows another embodiment of the present invention, and FIG. 10 shows the characteristics of the embodiment of FIG. 9. Further, FIG. 11 shows another embodiment of the present invention. Explanation of symbols in the figure 1... Applied force, 2... Electrode, 3... Conductive rubber. 4...Pedestal, 5...Transmission body, 30.Inner chamber. 31...Pressure receiving part, 32...Spring A, 33...Spring B. 34... Stopping plate, 35... Passage hole, 36... Inner chamber. 37. Cap, 38.. Pressing plate, 39.. Connecting shaft. 6...Pressure sensitive element, 51...Spring, 71...Diaphragm. 72, 73...elastic rubber, 74...side chamber. 81...Elastic body, 91...1llll'4.92...
diaphragm. 71-1 Fig. O 2 Fig. Applied force O 3 Fig. 5 O 4 Fig. Applied force (first force) 71-5 Fig. 71-6 Fig. Applied force (first force) Off Fig. 71-8 Fig. 71-9 Fig. 71-10 Figure applied force (first force)

Claims (1)

[Scope of Claims] a force transducer comprising the pressure sensitive element and ff, the second force having a nonlinear relationship with the first force; a pressure receiving section receiving the first force; a transmitting body that processes the first force into a second force and transmits it to the pressure-sensitive element; and the pressure-sensitive element that converts the second force into an electrical signal; A force transducer characterized by having a non-linear relationship with the first force.A force transducer characterized by having a plurality of force transducers arranged in a 7-lay pattern.