JPH06323933A - Force detection device - Google Patents

Abstract

PURPOSE:To provide a force detection device which can be mass-produced at comparatively low costs without requiring a high-degree machining operation. CONSTITUTION:A displacement board 20 as a disk-shaped board is arranged at the upper part of a disk-shaped fixed board 10. Fixed electrode layers E1 to E5 are formed on the surface of the fixed board 10, and displacement electrode layers F1 to F5 are formed on the rear surface of the displacement board 20. A disk-shaped filmlike rubber 30 is interposed and inserted between the fixed electrode layers E1 to E5 and the displacement electrode layers F1 to F5. A doughnut disk-shaped filmlike rubber 40 is arranged also on the surface of the displacement board 20. A device as a whole is surrounded by a cylindrical side-part enclosure 50, and it is fixed in a state that pressure claws 51 have pressed the filmlike rubber 40 downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a force detecting device, and more particularly to a force detecting device for detecting an applied force by utilizing a change in capacitance.

[0002]

2. Description of the Related Art A force detecting device for detecting an applied force as an electric signal is used in various machines including industrial machines. In particular, in recent years, there has been an increasing demand for a device capable of detecting the applied force for each multidimensional component. As described above, a device using a capacitance element has been proposed as a force detection device capable of performing force detection for multidimensional direction components and having a relatively simple structure.

For example, in Japanese Unexamined Patent Publication No. 4-148833, two substrates are arranged facing each other, and a plurality of electrodes are arranged on opposite surfaces of each substrate to form a plurality of sets of capacitance elements. A force detection device is disclosed. One of the substrates has a structure in which it is bent by the action of a force to be detected. When the substrate is bent by the action of force, the capacitance of each capacitance element changes based on the direction of the applied force. Therefore, by utilizing the change in capacitance of these capacitance elements, XYZ
The force acting in the three-dimensional coordinate system can be detected for each coordinate axis direction component.

[0004]

In the force detecting device using the electrostatic capacitance element described above, an important factor that influences the detection accuracy is the distance and parallelism between a pair of electrodes forming the electrostatic capacitance element. . Since the inter-electrode distance is an important element that directly changes the electrostatic capacitance, if the inter-electrode distance varies from product to product, the sensitivity from product to product also varies, It becomes impossible to obtain an accurate detection value. Further, when the parallelism of the electrode pair is lost, there is a problem that the detection value of the one-direction component interferes with the other-axis direction component.

For these reasons, in order to realize a highly accurate detection device, it is necessary to secure a constant distance between the electrodes for each product and to maintain the parallelism of both electrodes. However, in order to improve the accuracy of the distance between the electrodes and the parallelism, strict mechanical processing accuracy is required. As a result, the manufacturing cost increases.

Recently, the demand for this type of force detecting device has been
Demand is increasing not only for industrial machines but also as input devices for computer-related equipment. For example, in a home-use game computer, an input device called a "joystick" for use in game software is used. For devices used as accessories for such home appliances, the condition that mass production is possible at low cost is very important, so conventional capacitive force sensing devices that require advanced machining are Inappropriate.

Therefore, an object of the present invention is to provide a force detecting device which does not require high-level machining and can be mass-produced at a relatively low cost.

[0008]

[Means for Solving the Problems]

(1) The first invention of the present application is arranged so as to face a fixed substrate fixed to the apparatus casing or forming a part of the apparatus casing, above the fixed substrate and keeping a predetermined distance. The displacement substrate, the fixed electrode formed on the upper surface of the fixed substrate, the displacement electrode formed on the lower surface of the displacement substrate at a position facing the fixed electrode, and the elastic electrode inserted between the fixed electrode and the displacement electrode. A first elastic body made of a material having a material, a second elastic body provided on the upper surface of the displacement substrate and made of a material having elasticity, and a second elastic body having an upper surface A force detection device is configured by a support member that supports a fixed substrate so as to maintain a predetermined distance, and an action body that applies a force to the displacement substrate.

(2) According to a second aspect of the present invention, a fixed substrate fixed to the device casing or forming a part of the device casing faces a fixed substrate above the fixed substrate at a predetermined distance. The displacement substrate arranged, a plurality of fixed electrodes formed on the upper surface of the fixed substrate, a plurality of displacement electrodes formed on the lower surface of the displacement substrate at positions facing the respective fixed electrodes, each fixed electrode and each A first elastic plate member interposed between the displacement electrode and made of an elastic material, and a first elastic plate member provided at a peripheral portion of the upper surface of the displacement substrate and made of an elastic material. No. 2 elastic plate-shaped member, a support member for supporting the second elastic plate-shaped member so that its upper surface keeps a predetermined distance from the fixed substrate, and a displacement substrate attached to the central portion of the upper surface of the displacement substrate. An action body for exerting a force on
The force detection device is configured by the above.

(3) A third invention of the present application is the force detection device according to the above-mentioned second invention, wherein a supporting member is formed so as to extend upward from a peripheral portion of the fixed substrate, And a pressing claw formed to extend substantially horizontally from the upper end of the side housing toward the center, and the pressing claw can support the second elastic plate member while pressing it against the fixed substrate. It was done like this.

(4) The fourth invention of the present application is, in the force detecting device according to the above-mentioned second invention, XYZ three-dimensional such that the X axis and the Y axis intersect on a plane parallel to the upper surface of the fixed substrate. Defining a coordinate system, arranging the first fixed electrode and the first displacement electrode in the positive region of the X-axis, the second fixed electrode and the second displacement electrode in the negative region of the X-axis, The third fixed electrode and the third displacement electrode are arranged in the positive region of the Y axis,
The fourth fixed electrode and the fourth displacement electrode are arranged in the negative region of the Y axis, and the fifth fixed electrode and the fifth displacement electrode are arranged at the positions corresponding to the origin.

(5) According to a fifth aspect of the present invention, a fixed substrate fixed to the apparatus casing or forming a part of the apparatus casing faces a fixed substrate above the fixed substrate at a predetermined distance. The displacement substrate arranged, the upper substrate which is disposed above the displacement substrate so as to face each other with a predetermined distance and has a through hole formed in the central portion, and a plurality of fixed members formed on the upper surface of the fixed substrate. Electrodes, a plurality of displacement electrodes formed on the lower surface of the displacement substrate at positions facing the respective fixed electrodes, a plurality of auxiliary displacement electrodes formed on the upper surface of the displacement substrate, and respective auxiliary displacements on the lower surface of the upper lid substrate A plurality of auxiliary fixed electrodes formed at positions facing each of the electrodes, and a first elastic plate-shaped member interposed between each fixed electrode and each displacement electrode and made of a material having elasticity. , And is inserted between each auxiliary fixed electrode and each auxiliary displacement electrode, A second elastic plate member made of a material having elasticity and having a through hole in the central portion, a support member for supporting the upper lid substrate while pressing it against the fixed substrate, a through hole of the upper lid substrate, and An action body that is attached to the central portion of the upper surface of the displacement substrate through the through hole of the elastic plate member 2 and applies a force to the displacement substrate;
The force detecting device is configured by the above.

(6) A sixth invention of the present application is the force detecting device according to the fifth invention, wherein a supporting member is formed so as to extend upward from a peripheral portion of the fixed substrate, A pressure claw formed to extend substantially horizontally from the upper end of the side case toward the center, and the pressure claw allows the upper cover substrate to be supported while being pressed against the fixed substrate. is there.

(7) A seventh invention of the present application is the force detecting apparatus according to the fifth invention, wherein the X-axis and the Y-axis intersect on a plane parallel to the upper surface of the fixed substrate. A coordinate system is defined, and the first fixed electrode, the first displacement electrode, the first auxiliary displacement electrode, and the first auxiliary fixed electrode are respectively arranged in the positive region of the X axis, and the second fixed electrode is arranged. A second displacement electrode, a second auxiliary displacement electrode, and a second
The auxiliary fixed electrodes of are arranged in the negative region of the X-axis,
The third fixed electrode, the third displacement electrode, the third auxiliary displacement electrode, and the third auxiliary fixed electrode are arranged in the positive region of the Y axis, and the fourth fixed electrode and the fourth displacement electrode are arranged. , 4th
The auxiliary displacement electrode and the fourth auxiliary fixed electrode are respectively arranged in the negative region of the X axis, and the fifth fixed electrode, the fifth displaced electrode, the fifth auxiliary displaced electrode, and the fifth auxiliary fixed The electrodes are arranged at positions corresponding to the origin.

(8) The eighth invention of the present application is the above-mentioned second to seventh inventions.
In the force detection device according to any one of the present inventions, any one of the plurality of fixed electrodes or the plurality of displacement electrodes is configured by a single electrode layer.

(9) The ninth invention of the present application is the force detecting device according to the eighth invention, wherein the fixed substrate or the displacement substrate is made of a conductive material, and the substrate itself is used as a single electrode layer. It was done like this.

(10) The tenth invention of the present application is the above-mentioned fifth invention.
In the force detection device according to any one of the inventions 1 to 7, any one of the plurality of auxiliary displacement electrodes or the plurality of auxiliary fixed electrodes is configured by a single electrode layer.

(11) The eleventh invention of the present application is the above-mentioned first invention.
In the force detection device according to the invention of No. 0, the displacement substrate or the upper lid substrate is made of a conductive material, and the substrate itself is used as a single electrode layer.

[0019]

[Operation] In a force detection device that uses changes in capacitance,
Electrodes are formed on the opposing surfaces of the pair of substrates, respectively, and the opposing electrodes form a capacitance element. The feature of the present invention resides in that an elastic body is inserted between the electrodes facing each other. If a flat plate-shaped elastic body is used, one of the electrodes is supported in contact with the lower surface of the elastic body and the other electrode is in contact with the upper surface of the elastic body.
Therefore, the distance between both electrodes is governed by the thickness of the plate-like elastic body, and the parallelism between both electrodes is governed by the parallelism between the upper and lower surfaces of the plate-like elastic body. Since it is relatively easy to mass-produce a plate-shaped elastic body having a constant thickness and parallel to each other on the upper and lower sides, it is possible to mass-produce an accurate force detection device at low cost.

The displacement substrate is supported by the fixed substrate via the second elastic body. In other words, the displacement board
The lower elastic member is supported by the first elastic body and the upper elastic member is supported by the second elastic body. In this way, when a force from the acting body is applied to the displacement substrate supported by the elastic body from above and below, the displacement substrate can be displaced with a certain degree of freedom due to the elastic deformation of the elastic body. Then, this displacement is electrically detected as a change in capacitance, and as a result, it is possible to detect the applied force. Further, since the displacement substrate is supported from above and below, even if excessive force is applied from the acting body,
The displacement amount is limited within a certain range. Therefore, a function as a stopper against overload is provided.

[0021]

The present invention will be described below based on illustrated embodiments. FIG. 1 is a side sectional view of a force detection device according to an embodiment of the present invention, and FIG. 2 is a top view of this device. Fixed substrate 10
Is a disk-shaped substrate and forms a part of the housing of this device. A displacement substrate 20, which is also a disc-shaped substrate, is arranged above the fixed substrate 10. Five fixed electrode layers E1 to E5 are formed on the upper surface of the fixed substrate 10, and five displacement electrode layers F1 to F5 are formed on the lower surface of the displacement substrate 20 (in FIG. 1, these are shown). Only part of the electrode layer is visible). An elastic plate member 30 is interposed between the fixed electrode layers E1 to E5 and the displacement electrode layers F1 to F5. The elastic plate member 30 is a disk-shaped plate made of a material having elasticity. Another elastic plate member 40 is arranged on the upper surface of the displacement substrate 20. This elastic plate member 40 is also made of a material having elasticity, but as shown in FIG. 2, it has a so-called donut disk shape so that it can be arranged on the peripheral portion of the upper surface of the displacement substrate 20. .

Further, a cylindrical side case 50 is provided so as to surround the displacement board 20, the elastic plate member 30, and the elastic plate member 40. The lower end of the side casing 50 is fixed to the upper surface of the fixed substrate 10, and the upper end is formed with a pressing claw 51. The pressing claw 51 moves the elastic plate member 40 to the fixed substrate 10. Force is applied. That is, in the side sectional view of FIG. 1, the elastic plate member 40 is pressed downward by the pressing claws 51. Therefore, the elastic plate member 30 and the elastic plate member 40 are always in a state in which pressure is applied in the thickness direction. Further, the action body 60 is attached from the center of the upper surface of the displacement substrate 20 upward. The acting body 60 is a cylindrical rod-shaped member, and has a function of transmitting a force applied from the outside to the displacement substrate 20. The elastic plate member 40 and the side housing 5
0, the planar positional relationship of the acting body 60 is clearly shown in the top view of FIG. 2 (in FIG. 2, the side case 50 is shown with a part cut away).

In this specification, as shown in FIG. 1, the action point P is defined at the center position of the upper end of the action body 60, and the operation of detecting the force acting on this action point P will be described. . Here, for convenience of description, three coordinate axes XYZ as shown by the one-dot chain lines in FIGS. 1 and 2 are defined, and an XYZ three-dimensional coordinate system having the point of action P as the origin is defined. This force detecting device uses the X-axis direction component F of the force acting on the action point P.
It is possible to separately detect the x-axis direction component Fy and the Z-axis direction component Fz.

In order to perform such detection for each axial component, it is necessary to perform a specific electrode arrangement. Figure 3
Five fixed electrode layers E1 formed on the upper surface of the fixed substrate 10.
It is a figure which shows the shape and arrangement of E5. Fixed electrode layer E
1 to E4 are all fan-shaped electrode layers, which are arranged in the positive region and the negative region of the X axis, and in the positive region and the negative region of the Y axis, respectively. The fixed electrode layer E5 is a circular electrode layer and is arranged in the region corresponding to the origin. On the other hand, FIG. 4 is a diagram showing the shape and arrangement of the five displacement electrode layers F1 to F5 formed on the lower surface of the displacement substrate 20. The displacement electrode layers F1 to F4 are all fan-shaped electrode layers, and are arranged in the positive region and the negative region of the X axis, and the positive region and the negative region of the Y axis, respectively. Further, the displacement electrode layer F5 is a circular electrode layer and is arranged in a region corresponding to the origin. After all, the fixed electrode layers E1 to E5 and the displacement electrode layer F
1 to F5 are arranged at positions facing each other. Here, each of the capacitive elements formed by these five pairs of opposing electrode layers is referred to as a capacitive element C.
1 to C5. For example, the fixed electrode layer E1
The electrostatic capacitance element constituted by the displacement electrode layer F1 and the displacement electrode layer F1 opposed to this is called a capacitance element C1.

An elastic plate member 30 is inserted between the pair of electrodes forming each of the capacitive elements C1 to C5. Therefore, the distance between the two electrode pairs in a steady state in which no force acts on the force detection device is determined by the thickness of the elastic plate member 30 and the pressure acting in the thickness direction (the pressing claw 51.
Pressure), the parallelism of both electrode pairs is
It is determined by the parallelism between the upper surface and the lower surface of the elastic plate member 30. Therefore, if a plate-shaped member having a uniform thickness is used as the elastic plate-shaped member 30, it is possible to mass-produce a product in which the distance between the electrodes does not vary and both electrodes are kept in a certain parallelism. Is. Suitable for mass production because it does not require precise machining like conventional products,
The manufacturing cost can be reduced.

In this embodiment, as the elastic plate member 30 and the elastic plate member 40, commercially available film rubber is used. Such a film-shaped rubber has a substantially uniform thickness, satisfies the above-mentioned conditions, and is relatively inexpensive. Moreover, since rubber has a higher dielectric constant than air, the capacitance element of the device of the present application has a significantly higher sensitivity than the capacitance element in which only air is present between the electrodes as in the conventional force detection device. Increase. Although the dielectric constant varies depending on the rubber used, for example, the relative permittivity of silicon rubber is about 8 to 9, the relative permittivity of natural rubber is about 2.4, and the relative permittivity of neoprene rubber is about 5 to 7. Is also much higher than air. Further, in the embodiment shown in FIG. 1, the fixed substrate 10 and the displacement substrate 20 are substrates made of ceramics or glass epoxy, and each electrode layer is a layer formed by depositing a metal on these substrates. . Further, the side case 50 and the working body 60 are both made of plastic or metal, and can be manufactured at low cost as a whole. Note that the thickness of each part in FIG. 1 is not an actual dimensional ratio for convenience of description. In particular, the thickness of each electrode layer and the elastic plate member 30 is shown to be considerably thicker than it actually is.

Next, the operating principle of this force detecting device will be described. Now, let us consider, for example, as shown in FIG. 5, what kind of change occurs in each of the capacitive elements C1 to C5 when the force Fx in the X-axis direction acts on the point of action P of this device.
When the force Fx acts, as shown in the figure, the elastic plate member 3
0 and the elastic plate member 40 elastically deform, and the electrode layers E1,
The distance between F1 is reduced and the distance between the electrode layers E2 and F2 is increased. Therefore, the capacitance of the capacitive element C1 formed by the electrode layers E1 and F1 increases, and the electrode layer E
The capacitance of the capacitive element C2 formed by 2 and F2 decreases. The degree of increase / decrease increases with the magnitude of the force exerted. Also, the direction of the acting force reverses,
When the force-Fx acts, the increase / decrease relationship is reversed. Therefore, if the capacitance values of the capacitive elements C1 and C2 are monitored, the direction and magnitude of the force acting in the X-axis direction can be detected.

By the way, as shown in FIG. 5, when only the force Fx in the X-axis direction is applied, another capacitive element C is applied.
No change occurs in the capacitance values of 3, C4 and C5. This is because the distance between the electrode layers E3 and F3, the distance between the electrode layers E4 and F4, and the distance between the electrode layers E5 and F5 are all partially reduced, but they are widened in other portions, so that As a result, the capacitance value does not change. Therefore, when only the force Fx in the X-axis direction acts, a change in the capacitance value appears only in the capacitive elements C1 and C2,
The force Fx does not interfere with the other axis.

The same phenomenon occurs when the force Fy in the Y-axis direction acts on the point of action P. That is, the elastic plate member 30 and the elastic plate member 40 are elastically deformed, and the electrode layer E
The distance between 3 and F3 shrinks, and the distance between the electrode layers E4 and F4 increases. Therefore, the capacitance of the capacitive element C3 formed of the electrode layers E3 and F3 increases, and the capacitance of the capacitive element C4 formed of the electrode layers E4 and F4 decreases. Therefore, if the capacitance values of the capacitive elements C3 and C4 are monitored, the direction and magnitude of the force acting in the Y-axis direction can be detected.

Next, as shown in FIG. 6, when a force Fz in the Z-axis direction acts on the point of action P, each of the capacitive elements C1 to C5
Think about what kind of change will occur in. When the force Fz acts, as shown in the figure, the elastic plate member 30 and the elastic plate member 40 are elastically deformed, and the distance between all electrode layers is shortened. Therefore, the capacitance of all the capacitance elements C1 to C5 increases. However, since the capacitive elements C1 to C4 are used to detect the forces Fx and Fy as described above, the force Fz
Capacitance element C5 is used for detection of. Thus, due to the capacitance values of the capacitive elements C1 and C2, the X-axis direction component Fx of the applied force is obtained, and the Y-axis direction component Fy of the applied force is obtained due to the capacitance values of the capacitive elements C3 and C4. As a result, the Z-axis direction component Fz of the applied force is detected independently of each other.

In the above-mentioned embodiment, five fixed electrode layers E are used.
1 to E5 and the five displacement electrode layers F1 to F5,
Although five sets of capacitance elements C1 to C5 are formed, it is also possible to form one of the fixed electrode and the displacement electrode with a single common electrode layer. For example, the embodiment shown in FIG.
In this example, the displacement electrode layers F1 to F5 are replaced by a single common electrode layer F0. FIG. 8 is a view showing the shape of the common electrode layer F0 formed on the lower surface of the displacement substrate 20. Figure 8
3, the common electrode layer F0 is a disk-shaped electrode layer and faces all five fixed electrode layers E1 to E5 shown in FIG. Therefore, the common electrode layer F
Although 0 is physically one electrode layer, it will function as five displacement electrodes facing each of the five fixed electrode layers E1 to E5 shown in FIG. Contrary to the embodiment shown in FIG. 7, the fixed electrode side may be a single common electrode layer.

When using such a common electrode layer,
The structure of the device can be further simplified. For example,
As shown in FIG. 9, when the displacement substrate 20 is made of a conductive material such as metal, the displacement substrate 20 itself can be used as the common electrode layer F0.
There is no need to specially form a displacement electrode layer. Of course, when the fixed electrode side is shared, the fixed substrate 10 may be made of a conductive material such as metal.

After all, the merit of the force detecting device according to the present invention is that the structure in which the elastic body such as the film-like rubber is sandwiched between the two electrodes makes it possible to reduce the product in which the distance between both electrodes and the parallelism are stable. It is possible to mass-produce at a cost. Therefore, the force detection device according to the present invention is lower in cost than used for a measuring instrument that requires high accuracy,
It is more suitable for use in fields where mass production is required. For example, it is suitable for use as a so-called "joystick" as an input device for computers, word processors, video game machines and the like. The operator is the operator 6
While pinching 0 with a finger, an input operation such as tilting it in the X direction or the Y direction or pushing it in the Z direction can be performed. Further, in the force detection device according to the present invention, since the displacement substrate 20 is supported by the elastic body, the displacement substrate 2
The degree of freedom of displacement of 0 is large. Therefore, there is an advantage that it is easy to add a mechanism such as a stopper for limiting the displacement of the displacement substrate 20 when an excessive force is applied.

Next, an embodiment capable of further improving the detection sensitivity will be described. FIG. 10 shows a side sectional view of this embodiment. The fixed substrate 10, the displacement substrate 20, and the elastic plate member 30 in this embodiment are exactly the same as those in the above-described embodiments. The feature of this embodiment is that the elastic plate member 45 and the upper cover substrate 70 are arranged above the displacement substrate 20, and new auxiliary displacement electrode layers F6 to F10 (only a part is shown in FIG. 10). ) And an auxiliary fixed electrode layer E20
And, there is a point. The elastic plate-shaped member 45 and the upper lid substrate 70 are both donut-shaped plate-shaped members having a through hole in the center, and the acting body 60 is inserted into these through holes and attached to the upper surface of the displacement substrate 20. Has been. The elastic plate member 45 is made of a material having elasticity like the elastic plate member 30. Further, a force in the direction of pressing downward in the figure is applied to the upper cover substrate 70 by the pressing claw 51.

Next, the shape and arrangement of each electrode layer will be described. The fixed electrode layer E0 is a disk-shaped common electrode layer formed on the upper surface of the fixed substrate 10, and is an electrode having the same function as the five fixed electrode layers E1 to E5 shown in FIG.
The five displacement electrode layers F1 to F5 facing this have the shapes and arrangements shown in FIG. 4, and are the same as those in the above-described embodiment. After all, the fixed electrode layer E0 and the five displacement electrode layers F1
To F5 form five sets of capacitive elements C1 to C5, and these five sets of capacitive elements C1 to C5 form XY
The point that the force of each Z-axis direction component can be detected is exactly the same as the above-described embodiment.

In the device of this embodiment, five sets of capacitive elements are further formed. FIG. 11 is a diagram showing the shape and arrangement of the five auxiliary displacement electrode layers F6 to F10 formed on the upper surface of the displacement substrate 20. Each of the auxiliary displacement electrode layers F6 to F9 is a fan-shaped electrode layer, and is arranged in a positive region and a negative region of the X axis, and a positive region and a negative region of the Y axis, respectively. In addition, the auxiliary displacement electrode layer F10
Is a donut-shaped electrode layer having a through hole in the center,
It is arranged in a region corresponding to the origin (the broken line in FIG. 11 shows the attachment position of the working body 60). On the other hand, FIG.
Is an auxiliary fixed electrode layer E formed on the lower surface of the upper cover substrate 70.
It is a figure which shows the shape and arrangement | positioning of 20 (the broken line of FIG. 12 shows the insertion position of the effector 60). This auxiliary fixed electrode layer E20 includes five auxiliary displacement electrode layers F6 to F6 shown in FIG.
It functions as five electrodes facing each of F10. Eventually, these electrode layers form five sets of capacitive elements. Here, the capacitive elements formed by these five pairs of opposing electrode layers will be referred to as capacitive elements C6 to C10, respectively. For example, the capacitive element configured by the auxiliary displacement electrode layer F6 and the auxiliary fixed electrode layer E20 facing the auxiliary displacement electrode layer F6 is called a capacitive element C6.

As described above, in the apparatus of this embodiment,
Although a total of 10 sets of capacitive elements C1 to C10 are formed, considering these arrangements, the capacitive elements C1 and C6 are
The capacitive elements C2 and C7 are located in the positive area of the axis, the capacitive elements C2 and C7 are located in the negative area of the X axis, the capacitive elements C3 and C8 are located in the positive area of the Y axis, and the capacitive elements C4 and C9 are located in the positive area of the Y axis. The capacitive elements C5 and C10 are arranged in the negative region, and are arranged at positions corresponding to the origin. Moreover, the capacitive element C6
To C10 are arranged directly above the capacitive elements C1 to C5, respectively. Therefore, the change in capacitance of the capacitive element C1 and the change in capacitance of the capacitive element C6 are completely opposite.
Similarly, the changes in the capacitance elements C2 and C7 are also completely opposite, and the changes in the capacitance elements C3 and C8 are also completely opposite.
The changes in C4 and C9 are also reversed, and the capacitance elements C5 and C10
The change of is also the opposite. For example, considering the case where a force Fx in the X-axis direction is applied to the acting body 60 in FIG. 10, the distance between the electrode layers E0-F1 is shortened, so that the capacitive element C
Although the capacitance of No. 1 increases, the distance between the electrode layers F6 and E20 widens conversely, so that the capacitance of the capacitive element C6 decreases conversely.

After all, in the apparatus of this embodiment, the displacement substrate 2
The five sets of capacitive elements C1 to C5 provided below 0 can detect the XYZ axial components of the applied force, and the five sets of capacitive elements C6 to C6 provided above the displacement substrate 20. The same detection can be performed by C10. Therefore, a total of 10 sets of capacitive elements C1 to
If the detection using C10 is performed, the detection can be performed with twice the sensitivity of the above-described embodiment. FIG. 13 shows the force F in each axial direction.
It is a table which shows the change of the electrostatic capacitance about these 10 sets of capacitive elements C1-C10 when x, Fy, and Fz act. In this table, "+" indicates that the capacitance value increases, "-" indicates that the capacitance value decreases, and "0" indicates that the capacitance value does not change. It can be understood that the results shown in the table of FIG. 13 can be obtained by considering the displacement state of the displacement substrate 20 when a force in each axial direction is applied to the device shown in FIG. Although the fixed electrode layer E0 and the auxiliary fixed electrode layer E20 are the common electrode layers in the embodiment shown in FIG. 10, the displacement electrode layers F1 to F5 or the auxiliary displacement electrode layers F6 to F10 may be the common electrode layers. Absent.

Finally, FIG. 14 shows an example of the detection circuit applicable to the embodiment shown in FIG. Where C1 to C10
Indicates 10 sets of capacitive elements C1 to C10. Figure 1
The fixed electrode E0 and the auxiliary fixed electrode E20 at 0 are
All are common electrodes that also serve as five electrodes.
In forming the circuit shown in (1), the common electrode side may be grounded. The capacitance value of each capacitance element is the C / V conversion circuit 81.
˜86, it is converted into a voltage value and given to the subtracters 87 to 89. Then, at the output terminal Tx of the subtractor 87,
A voltage value corresponding to the X-axis direction component Fx of the applied force is output, and the output terminal Ty of the subtractor 88 outputs Y of the applied force.
The voltage value corresponding to the axial component Fy is output, and the subtracter 8
The output terminal Tz of 9 has a Z-axis direction component Fz of the applied force.
The voltage value corresponding to is output. The reason for this can be easily understood by referring to the table of FIG. For example, looking at the column of force Fx, “+” is displayed for the capacitive elements C1 and C7, and “−” is displayed for the capacitive elements C2 and C6. Therefore, the voltage value (V1 + V7) corresponding to the sum of the capacitance values of the capacitance elements C1 and C7 and the capacitance elements C2 and C
If the difference between the voltage value (V2 + V6) corresponding to the sum of the capacitance values of 6 and the subtractor 87 is obtained, Fx = (V1 + V7) −
The force Fx can be calculated as (V2 + V6). Similarly, the force Fy can be obtained by Fy = (V3 + V9)-(V4 + V8), and the force Fz can be obtained by Fz = (V5-V10).

FIG. 15 shows an example of another detection circuit applicable to the embodiment shown in FIG. In this circuit, the capacitive element C
The capacitance values of 1 to C10 are C / V conversion circuits 91 to 98.
And 85,86 are converted into voltage values V1 to V10. Further, as a result of the subtraction by the subtracters 101 to 104 and 89 and the addition by the adders 105 and 106, forces Fx, Fy, Fz are applied to the output terminals Tx, Ty, Tz.
Is obtained. Here, the circuit portion for obtaining the force Fz is exactly the same as the circuit shown in FIG. 14, but the forces Fx, F
The difference is that the circuit portion for obtaining y is subtracted first.

Although the present invention has been described above based on some embodiments, the present invention is not limited to these embodiments and can be implemented in various modes other than this. For example, in the above-described embodiment, the displacement substrate 20, the elastic plate-shaped member 30, the elastic plate-shaped member 40, and the like are fixed by the pressing force of the pressing claw 51, but the substrate, the electrode layer, and the elastic plate-shaped member that are in contact with each other. The members and the like may be bonded together. By adopting such a constitution that they are adhered to each other, the pressing force by the pressing claw 51 is not always necessary. That is, in the embodiment shown in FIG. 1, the pressing claw 51 has a function of supporting the elastic plate member 40 from above so that the upper surface of the elastic plate member 40 maintains a predetermined distance from the fixed substrate. However, it is not always necessary to apply a downward pressing force to the drawing. Similarly, FIG.
In the embodiment shown in FIG.
Need only have a function to support the fixed substrate 10 at a position keeping a predetermined distance, and it is not always necessary to constantly apply a downward pressing force in the drawing.

In the above embodiment, the elastic plate member 3 is used.
Film rubber is used as 0, 40, 45,
Any material may be used as long as it has elasticity. In particular, the elastic plate member 40 includes
Since the function as a dielectric is not required, the elastic plate member 40 may be composed of a spring or the like. Also,
Although the fixed substrate 10 constitutes a part of the device housing in the above-described embodiment, it is not always necessary to do so, and the fixed substrate 10 may be fixed to another device housing.

[0043]

As described above, in the force detecting device according to the present invention, since the elastic body is inserted between the electrodes formed on the opposing surfaces of the pair of substrates, the distance between both electrodes is kept constant and the parallelism is improved. Can be easily maintained, and the accurate force detection device can be mass-produced at low cost.

[Brief description of drawings]

FIG. 1 is a side sectional view of a force detection device according to an embodiment of the present invention.

FIG. 2 is a top view of the embodiment shown in FIG.

FIG. 3 is a diagram showing shapes and arrangements of five fixed electrode layers E1 to E5 formed on the upper surface of a fixed substrate 10 of the embodiment shown in FIG.

FIG. 4 is a diagram showing the shape and arrangement of five displacement electrode layers F1 to F5 formed on the lower surface of the displacement substrate 20 of the embodiment shown in FIG.

5 is a side sectional view showing a state in which a force Fx in the X-axis direction acts on the device of the embodiment shown in FIG.

6 is a side sectional view showing a state in which a force Fz in the Z-axis direction is applied to the device of the embodiment shown in FIG.

FIG. 7 shows five displacement electrode layers F in the embodiment shown in FIG.
It is a side sectional view showing an example which replaced 1-F5 with a single common electrode layer F0.

8 is a diagram showing the shape and arrangement of a common electrode layer F0 formed on the lower surface of the displacement substrate 20 of the embodiment shown in FIG.

9 is a side sectional view showing an embodiment in which the common electrode layer F0 in the embodiment shown in FIG. 7 is replaced with a displacement substrate 20 made of metal.

FIG. 10 is a side sectional view of a force detection device according to another embodiment of the present invention, which enables detection with higher sensitivity.

11 is a diagram showing the shape and arrangement of five auxiliary displacement electrode layers F6 to F10 formed on the upper surface of the displacement substrate 20 of the embodiment shown in FIG.

12 is a diagram showing the shape and arrangement of a single auxiliary fixed electrode layer E20 formed on the lower surface of the upper lid substrate 70 of the embodiment shown in FIG.

13 is a diagram showing a configuration of ten sets of capacitive elements C when forces Fx, Fy, Fz in respective axial directions act on the device of the embodiment shown in FIG.
It is a table which shows the change of the electrostatic capacitance about 1-C10.

14 is a circuit diagram showing an example of a detection circuit applicable to the device of the embodiment shown in FIG.

15 is a circuit diagram showing another example of the detection circuit applicable to the device of the embodiment shown in FIG.

[Explanation of symbols]

 10 ... Fixed substrate 20 ... Displacement substrate 30 ... Elastic plate member 40 ... Elastic plate member 45 ... Elastic plate member 50 ... Side casing 51 ... Pressing claw 60 ... Actuator 70 ... Upper lid substrate 81-86 ... C / V conversion circuit 87-89 ... Subtractor 91-98 ... C / V conversion circuit 101-104 ... Subtractor 105, 106 ... Adder C1-C10 ... Capacitance element E0, E1-E5 ... Fixed electrode layer (E0 is a common electrode) Layer) F0, F1 to F5 ... Displacement electrode layer (F0 is a common electrode layer) F6 to F10 ... Auxiliary displacement electrode layer E20 ... Auxiliary fixed electrode layer (common electrode layer) Tx, Ty, Tz ... Output terminals

Claims (11)

[Claims] 1. A fixed substrate fixed to the device casing or forming a part of the device casing; and a displacement substrate arranged above the fixed substrate so as to face each other with a predetermined distance therebetween. A fixed electrode formed on an upper surface of the fixed substrate, a displacement electrode formed on a lower surface of the displacement substrate at a position facing the fixed electrode, and an elastic member inserted between the fixed electrode and the displacement electrode. A first elastic body made of a material having a material, a second elastic body provided on the upper surface of the displacement substrate and made of a material having elasticity, and a second elastic body A force detection device comprising: a support member that supports the upper surface of the fixed substrate so as to maintain a predetermined distance from the fixed substrate; and an action body that applies a force to the displacement substrate. 2. A fixed substrate fixed to the device casing or forming a part of the device casing; a displacement substrate arranged above the fixed substrate so as to face each other with a predetermined distance therebetween; A plurality of fixed electrodes formed on the upper surface of the fixed substrate, a plurality of displacement electrodes formed on the lower surface of the displacement substrate at positions facing the fixed electrodes, respectively, the fixed electrodes and the displacement electrodes A first elastic plate-like member interposed between the first and second elastic plate members, and a second elastic plate member provided around the upper surface of the displacement substrate and made of an elastic material. An elastic plate member, a support member that supports the second elastic plate member so that an upper surface of the second elastic plate member maintains a predetermined distance from the fixed substrate, and the elastic plate member is attached to a central portion of an upper surface of the displacement substrate, An actuator for exerting a force on the displacement substrate , The force detection device characterized in that it comprises a. 3. The force detection device according to claim 2, wherein the support member is provided with a side case formed so as to extend upward from a peripheral portion of the fixed substrate, and a support member is centered from an upper end of the side case. And a pressing claw formed so as to extend substantially horizontally toward the second elastic plate member by the pressing claw so as to support the second elastic plate member while pressing it against the fixed substrate. Force detection device. 4. The force detection device according to claim 2, wherein an XYZ three-dimensional coordinate system is defined in which the X axis and the Y axis intersect on a plane parallel to the upper surface of the fixed substrate, and the first fixed The electrode and the first displacement electrode are arranged in the positive region of the X axis, the second fixed electrode and the second displacement electrode are arranged in the negative region of the X axis, and the third fixed electrode and the third displacement electrode are arranged. The electrode is arranged in the positive region of the Y axis, the fourth fixed electrode and the fourth displacement electrode are arranged in the negative region of the Y axis, and the fifth fixed electrode and the fifth displacement electrode correspond to the origin. A force detection device characterized by being placed in a position. 5. A fixed substrate fixed to the device housing or forming a part of the device housing, and a displacement substrate arranged above the fixed substrate so as to face each other with a predetermined distance therebetween. An upper lid substrate, which is arranged above the displacement substrate so as to face each other with a predetermined distance, and has a through hole formed in the central portion, a plurality of fixed electrodes formed on the upper surface of the fixed substrate, and the displacement substrate of the displacement substrate. A plurality of displacement electrodes formed on the lower surface at positions facing the respective fixed electrodes, a plurality of auxiliary displacement electrodes formed on the upper surface of the displacement substrate, and a plurality of auxiliary displacement electrodes on the lower surface of the upper lid substrate. A plurality of auxiliary fixed electrodes formed at positions facing each other, and a first elastic plate member interposed between the fixed electrodes and the displacement electrodes and made of a material having elasticity. And each auxiliary fixed electrode and each auxiliary A second elastic plate member that is inserted between the upper electrode and the upper electrode and is made of an elastic material and has a through hole in the central portion; A support member that supports the retained position, a through hole of the upper lid substrate, and a through hole of the second elastic plate member are inserted to be attached to the central portion of the upper surface of the displacement substrate, and force applied to the displacement substrate. A force detection device, comprising: an action body for causing 6. The force detection device according to claim 5, wherein the support member is provided with a side case formed so as to extend upward from a peripheral portion of the fixed substrate, and a support member centered from an upper end of the side case. And a pressing claw formed so as to extend substantially horizontally toward the upper cover substrate while pressing the upper cover substrate against the fixed substrate by the pressing claw. 7. The force detection device according to claim 5, wherein an XYZ three-dimensional coordinate system is defined such that the X axis and the Y axis intersect on a plane parallel to the upper surface of the fixed substrate, and the first fixed The electrode, the first displacement electrode, the first auxiliary displacement electrode, and the first auxiliary fixed electrode are respectively arranged in the positive region of the X axis, and the second fixed electrode, the second displacement electrode, and the second The auxiliary displacement electrode and the second auxiliary fixed electrode are respectively arranged in the negative region of the X axis, and the third fixed electrode, the third displacement electrode, the third auxiliary displacement electrode, and the third auxiliary fixed electrode. Are respectively arranged in the positive region of the Y-axis, and the fourth fixed electrode, the fourth displacement electrode, the fourth auxiliary displacement electrode, and the fourth auxiliary fixed electrode are arranged in the negative region of the X-axis, respectively. The fifth fixed electrode, the fifth displacement electrode, the fifth auxiliary displacement electrode, and the fifth auxiliary fixed electrode. A force detecting device characterized in that poles are arranged at positions corresponding to respective origins. 8. The force detection device according to claim 2, wherein either one of the plurality of fixed electrodes or the plurality of displacement electrodes is composed of a single electrode layer. Force detection device. 9. The force detection device according to claim 8, wherein the fixed substrate or the displacement substrate is made of a conductive material,
A force detection device characterized by using this substrate itself as a single electrode layer. 10. The force detection device according to claim 5, wherein either one of the plurality of auxiliary displacement electrodes or the plurality of auxiliary fixed electrodes is formed of a single electrode layer. Characteristic force detection device. 11. The force detection device according to claim 10, wherein the displacement substrate or the upper lid substrate is made of a conductive material,
A force detection device characterized by using this substrate itself as a single electrode layer.