JPH08207755A - In-hole moving device - Google Patents

Abstract

PURPOSE: To provide an in-hole moving device moving at high speed while being compact, lightweight and low in demand. CONSTITUTION: An in-hole moving device is provided with a plane deformable element 1 with the curvature changed by applied voltage, a weight 2 fixed to either one of the center part and the peripheral part of the element 1, a leg part 3 fixedly held to the other one of the center part and the peripheral part and brought into contact with the inner wall surface forming a surrounding hole, and a control means for supplying the applied voltage of controlled waveform to the plane deformable element 1. The plane deformable element 1 can be formed of a piezoelectric unimorph or a piezoelectric bimorph 1, and the leg part 3 can be formed of plural clamping legs 3 formed of spring elastic material. Since displacement between the center part and the peripheral part generated by the curvature change of the plane deformable element 1 is large, this in-hole moving device can move rapidly in the hole while being of extremely short and compact shape and low in demand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hole moving device that moves by itself in a hole such as a pipe. The pipes include not only industrial pipes, domestic pipes for gas / water, etc., pipes in the reactor, but also living body pipes. The in-hole moving device can be used for inspection of piping by attaching various sensors, and can also be used for spraying a drug in the hole.

[0002]

2. Description of the Related Art A conventional hole moving device is disclosed in Japanese Patent Laid-Open No.
There is a self-propelled device in a tube disclosed in Japanese Patent Publication No. 176770. This is, as shown in FIG. 11, provided with a weight 102 at one end of a piezoelectric laminated actuator 101 which can be expanded and contracted in the axial direction by an applied voltage, and a leg portion 103 having a mass more than twice the weight 102 at the other end. Is. In this intra-hole moving device, the applied voltage control means 104 slowly expands and contracts the actuator 101 to expand and contract the leg portion 1.
It is possible to move forward or backward little by little by utilizing the difference between the frictional force generated between 03 and the wall surface abutting this and the inertial force generated by the weight 102 due to the expanding and contracting actuator 101.

[0003]

However, in the hole moving device according to the above-mentioned prior art, since the expansion / contraction stroke of the piezoelectric laminated actuator is extremely short (about 6 μm when 100 V is applied to the actuator having a length of 9 mm), it is possible to perform the operation once. The pitch (distance) that can be moved by the expansion and contraction operation is extremely small. Therefore, there is a disadvantage that the moving speed is slow.

In order to overcome this with the conventional technique, the length of the actuator is extended, the mass of the weight is increased, or the applied voltage is increased to shorten the period. However, if you extend the actuator, the total length will increase,
Can't enter into a winding hole. In addition, there is a limit to weighting the weight and increasing the applied voltage, which causes problems such as imbalance and heating due to power consumption, so that a dramatic effect cannot be expected at present.

Therefore, an object of the present invention is to provide an in-hole moving device which has a relatively small size, light weight, and low power consumption, but has a high moving speed.

[0006]

In order to achieve the above-mentioned object, the hole moving device of the first structure of the present invention has a plane deforming element whose curvature is changed by an applied voltage, and a central portion or an outer periphery of the plane deforming element. A weight fixed to one of the portions, a leg portion fixedly held on the other of the central portion or the outer peripheral portion of the plane deforming element and abutting on an inner wall surface forming a peripheral hole, and a waveform controlled by the plane deforming element And a control means for supplying the applied voltage.

In the hole moving device of the second structure of the present invention, in the first structure, the plane deformation element is a flat plate made of a spring elastic material and a plate-shaped piezoelectric body bonded and fixed to at least one surface of the flat plate. And a piezoelectric unimorph or a piezoelectric bimorph composed of the piezoelectric plate. Here, the piezoelectric bimorph means a bimorph piezoelectric element (bimorphcel).
Also called l), two piezoelectric plates are joined together so that the applied voltage stretches one of the piezoelectric plates and compresses the other, and bends in proportion to the applied voltage.

In the hole moving apparatus of the third structure of the present invention, in the second structure, the flat plate is a disk made of a metal material which also serves as an electrode of the piezoelectric plate. In the hole moving device of the fourth structure of the present invention, in the first structure, the leg portion is formed by a plurality of clamp legs made of a spring elastic material. According to a fifth aspect of the present invention, in the hole moving device of the fourth aspect, the clamp legs are provided on both sides of the plane deformation element, respectively.

In the hole moving device of the first structure, the control means may be provided integrally with other portions including the plane deformation element, or may be provided separately from the other portions. When the control means is provided at a position apart from the plane deformation element or the like, an electric wire or a radio energy transmission / reception device can be provided as means for transmitting the applied voltage. Further, when the control means is integrally provided with the planar deformation element, the control means including the battery can also serve as the weight. Furthermore, it is possible to provide an autonomous driving means for autonomously controlling the operation or a remote control means. As a transmission medium for remote control, radio waves, sound waves including ultrasonic waves, light rays including infrared rays, and the like can be used.

[0010]

In the hole moving device of the first structure of the present invention, since the curvature of the plane deformation element changes depending on the applied voltage, the moving stroke (displacement) of the weight becomes large. In addition, since the thickness (length in the axial direction) of the plane deformation element is short, the overall length is short and the size can be reduced. As a result, according to the hole moving device of the present invention, while being relatively small,
The moving speed is high. Since the hole moving device has a short length, it can move in a well-balanced manner even in a curved hole.

In the hole moving device of the second structure of the present invention, since the piezoelectric plate is used for the plane deforming element, the same effect as the first structure can be obtained, and at the same time, the plane deforming element can be made extremely thin. become. For example, in a piezoelectric unimorph having a diameter of 12 mm, a displacement of about 30 μm can be obtained with a length (thickness) of 0.2 mm. Moreover, it is lightweight and consumes little power. In addition, the simple structure has the effect of increasing reliability.

In the hole moving device of the third structure of the present invention, since the metal disk also serves as the electrode of the piezoelectric plate, the structure of the plane deformation element can be made simpler, lighter, cheaper and more reliable. be able to. In the hole moving device of the fourth configuration of the present invention, since the plurality of clamp legs abut the wall surface of the surrounding holes with spring elasticity, the hole moving device is supported by the simple, lightweight and inexpensive leg portion, and at the same time, The specific gravity of the mass of the weight with respect to the total mass is increased, and the moving speed can be improved. Further, the spring elasticity of the clamp leg can cope with a change in the diameter of the inner surface of the hole to some extent.

In the hole moving device of the fifth structure of the present invention, the clamp legs provided on both sides support the hole moving device in the front and rear directions, so that the stability is further improved. Therefore, according to the present invention, while being small and lightweight and low power consumption,
It is possible to provide an intra-hole moving device having a moving speed much higher than that of the conventional one.

[0014]

Embodiments of the present invention will be described below with reference to FIGS. (Structure of Embodiment 1) As shown in FIGS. 1 and 2, the hole moving device of Embodiment 1 of the present invention has disk-shaped piezoelectric plates 11 and 12 on both sides of a disk 10 made of a spring alloy. 1 has a piezoelectric bimorph 1 bonded to and fixed to it, a weight 2 fixed to the center thereof, and three clamp legs 3 made of a spring alloy whose one end is fixed to the outer peripheral portion of the disk 10. In addition to this, a control means (not shown) is provided outside the hole and supplies an applied voltage having a controlled waveform to the bimorph 1 through an electric wire (not shown).

Here, there are three clamp legs 3 and 12
They are arranged at intervals of 0 degree, and each of them is formed from a single wire made of a spring alloy. That is, one wire having an appropriate length is bent at an intermediate portion to form a tip portion, and both tips of the folded wire are welded and fixed to the outer peripheral portion of the disk 10. The clamp leg 3 extends from the outer peripheral portion of the disk 10 to the peripheral wall surface W forming the hole while spreading in the centrifugal direction at a shallow angle. The tip portion is bent toward the centripetal side, and is in contact with the wall surface W of the hole at the bent portion,
It has a shape that does not easily get caught in the unevenness on the wall surface W.

On the other hand, the piezoelectric bimorph 1 is a flat disc 1
0 is a plane-deformable element in which disk-shaped piezoelectric plates 11 and 12 are bonded and fixed to both sides of 0, and the piezoelectric plates 11 and 12 are formed of piezoelectric materials having different polarization directions. Therefore, disk 1
When 0 is grounded and a positive voltage is applied to the piezoelectric plates 11 and 12, the bimorph 1 warps upward as shown in FIG. 3, and when a negative voltage is applied, as shown in FIG. Warp downwards. Therefore, since the curvature of the bimorph 1 changes depending on the applied voltage, a displacement in the axial direction occurs between the central portion and the outer peripheral portion of the bimorph 1, and the bimorph 1 acts as a kind of actuator. The stroke of a bimorph having a diameter of about 1 cm reaches several tens of μm. Incidentally, its length (thickness) is only about 0.3 mm.

(Operation of Embodiment 1) In the hole moving device configured as described above, the wall surface W on which the clamp leg 3 abuts.
Bimorph 1 that changes the curvature and the frictional force generated between
Utilizing the difference from the inertial force generated by weight 2 due to
It can move forward or backward in the hole. That is, first, when the voltage applied to the bimorph 1 is rapidly changed and a rapid acceleration is applied to the weight 2, the inertial force generated by the weight 2 becomes dominant, and the clamp leg 3 that abuts the wall surface W.
Surpasses the frictional force generated in. Then, the in-hole moving device of the present embodiment can move the clamp leg 3 with respect to the wall surface W without changing the position of the mass center of the weight 2 as a center. Next, if the applied voltage to the bimorph 1 is gently changed and the weight 2 is slowly pulled back without applying a large acceleration, the inertial force generated by the weight 2 is small and the wall surface generated on the clamp leg 3 is small. W
The friction force with becomes dominant. Then, the center of mass of the in-hole moving device mainly composed of the weight 2 can be moved with respect to the hole while the clamp leg 3 is fixed to the wall surface W.

By repeatedly performing such an operation of the applied voltage by the control means, the hole moving device of this embodiment can arbitrarily move forward or backward in the hole. This state is schematically shown in FIG. 5 for the forward operation and in FIG. 6 for the backward operation, where Xf is the forward direction, Xb is the backward direction, and I is the inertial force. The hole moving device of the present embodiment is small and lightweight and has a small weight, so that the influence of gravity is not dominant.

(Effect of Embodiment 1) Since the in-hole moving device of this embodiment uses the plane deformation element, it is relatively small and lightweight and consumes less power than a conventional piezoelectric actuator having a laminated piezoelectric actuator. However, it can move through the holes much more quickly without heating. In particular, the effect of greatly reducing the length of the hole along the extending direction is also remarkable.

Further, the bimorph 1 is used as a plane deformation element.
Therefore, compared with the one using unimorph, both displacement and deformation force are large with the same applied voltage, and the moving speed can be further improved. A unimorph may be used instead of the bimorph 1 as the plane deformation element.

(Embodiment 2) The hole moving device of this embodiment is
As shown in FIGS. 7 and 8, the weight 21 fixed to the outer peripheral portion of the piezoelectric bimorph 1 and a plurality of clamp legs 3 protruding from the central portion of both surfaces of the bimorph 1 to the periphery.
Have and. Further, as in the first embodiment, it has a control device not shown.

Here, the configuration of the bimorph 1 is the same as that of the first embodiment.
Almost the same as the above, but the leg bases 30 supporting the clamp legs 3 are welded to both sides of the central portion of the metal disk 10. Therefore, the piezoelectric plates 11 and 12 have a circular hole in the portion and have a donut-shaped planar shape. On the other hand, the weight 21 is an arc-shaped metal weight, and is a bimorph 1.
The four metal plates 10 are welded and fixed back to back on each side of the outer peripheral surface of the metal disc 10 at intervals of 90 degrees. Also,
The clamp legs 3 are made of a wire made of a spring alloy, and are arranged on both sides of the bimorph 1 so that a plurality of clamp legs 3 are provided from the center leg base 30 (two in each figure, but three or more are provided). May be projected) and is in contact with the inner wall surface W forming a peripheral hole.

The in-hole moving device of this embodiment is a bimorph 1
Hold the clamp leg 3 in the center of the
However, the moving action by applying a voltage to the bimorph 1 is similar to that of the first embodiment. Therefore, similar to the first embodiment, it is possible to move in the hole much more quickly without heating, while being small and lightweight and low in power consumption. Further, since the clamp legs 3 provided on both sides support the front and rear, there is an effect that the stability is further enhanced.

It is also possible to use a unimorph instead of the bimorph 1 as the plane deformation element. (Embodiment 3) As shown in the structure of FIG. 9, the hole moving device of this embodiment has a pair of unimorphs 1 provided coaxially opposite to each other and a cylindrical weight 2 connecting the central portions thereof.
2 and three clamp legs 3 each fixed to the outer periphery of the unimorph 1 by welding. A control means (not shown) is provided outside the hole, and an electric wire (not shown) applies an applied voltage synchronized with the pair of unimorphs 1.

The unimorph 1 is composed of a metal disk 10 made of a spring elastic material, and a piezoelectric plate 1 which is a disk-shaped piezoelectric body bonded to one side (side opposite to each other) of the metal disk 10.
It consists of 1. One electrode of the piezoelectric plate 11 is a metal disk 1
0 also serves as this, and the other electrode is provided on the other side to form a piezoelectric element. The diameter of the piezoelectric plate 11 is slightly smaller than the diameter of the metal disk 10, and the exposed metal disk 1
The clamp leg 3 attached to the outer peripheral portion of 0 projects rearwardly from the weight 22 connecting the opposing unimorphs 1 at the central portion thereof, and is in contact with the peripheral wall surface W. The clamp leg 3 is the same as that of the first embodiment.

The hole moving device of the present embodiment is constructed as described above, and if the applied voltage synchronized by the control means (not shown) is applied to the pair of unimorphs 1, the same driving principle as that of the first embodiment is obtained. The action of moving forward or backward occurs. As a result, similarly to the first embodiment, it is possible to move in the hole much more quickly without heating while it is small and lightweight and has low power consumption. At the same time, since the unimorph 1 is used as the plane deformation element, it is possible to apply a high voltage near the dielectric breakdown limit without fear of repolarization of the piezoelectric element, and it is possible to move more quickly.

Further, since the pair of unimorphs 1 support the clamp legs 3 at positions separated from each other in the front-rear direction, the stance becomes wider than that of the second embodiment, and the stability is further enhanced. Further, since the two plane deformation elements are used, the payload (paid load: a device such as a sensor carried by the in-hole moving device, a medicine, etc.) can be increased nearly twice. It is also possible to mount the payload in the space around the weight 22.

It is also possible to use a bimorph instead of the unimorph 1 as the plane deformation element. (Embodiment 4) As shown in FIG. 10, the hole moving device of this embodiment has a pair of bimorphs 1 facing each other and a hollow member fixedly contacted with the entire circumference of the outer peripheral portion thereof. It has a cylindrical weight 20 and a clamp leg 3 that is fixed to the central portions of the surfaces of the pair of bimorphs 1 facing each other and abuts against the peripheral wall surface W. Then, similarly to the third embodiment, a control means (not shown) is provided to apply an applied voltage synchronized with the pair of bimorphs 1.

Each of the pair of bimorphs 1 has a metal disk 10 having spring elasticity, a disk-shaped piezoelectric plate 11 bonded to the surfaces facing each other, and a circle at the center bonded to the surface facing the opposite side. It is composed of a disk-shaped piezoelectric plate 12 having holes.
The leg bases 30 are welded and fixed to the exposed portions of the metal disks 10 at the central portions of the back surfaces. Then, as in the second embodiment, one end of each clamp leg 3 is fixedly supported by each leg base 30, and the other end of each clamp leg 3 abuts on the surrounding wall surface W to move in the hole. I support you.

On the other hand, the piezoelectric plates 11 and 12 of each bimorph 1
Has a smaller diameter than the metal disk 10, so the bimorph 1
The metal disk 10 is exposed at the outer peripheral portion of the. A metal hollow cylindrical weight 20 is welded and fixed to the exposed metal portion. The weight 20 has a joining portion (not shown), which is detachably joined, so that the internal space formed by the hollow cylindrical weight 20 and the pair of bimorphs 1 can be accessed. There is.

The hole moving device of this embodiment is constructed as described above, and if the applied voltage synchronized by the control means (not shown) is applied to the pair of unimorphs 1, it is exactly the same as each of the above embodiments. The driving principle causes an action of moving forward or backward. As a result, similarly to the third embodiment, it is possible to move in the hole much more quickly without heating, while being small in size, light in weight, and low in power consumption, and the stability is further improved. Moreover, not only can the payload (paid load) be increased nearly twice by adopting two plane deformation elements, but also because it has a large cylindrical internal space, it can be used as a drug storage container or an electronic device for sensors. Can be used as a storage space.

A unimorph may be used instead of the bimorph 1 as the plane deformation element.

[Brief description of drawings]

FIG. 1 is a side view of the hole moving device according to the first embodiment inside the hole.

FIG. 2 is a perspective view of the in-hole moving device according to the first embodiment.

FIG. 3 is an explanatory diagram showing the operation of the bimorph.

FIG. 4 is an explanatory diagram showing the operation of the bimorph.

FIG. 5 is a schematic diagram of the action of forward movement according to the first embodiment.

FIG. 6 is a schematic diagram of the action of the backward movement according to the first embodiment.

FIG. 7 is a side sectional view of the hole moving device according to the second embodiment inside the hole.

FIG. 8 is a perspective view of the hole moving device according to the second embodiment.

FIG. 9 is a side view in the hole of the hole moving device according to the third embodiment.

FIG. 10 is a side sectional view of the hole moving device according to the fourth embodiment inside the hole.

FIG. 11 is a schematic view of a conventional hole moving device.

[Explanation of symbols]

1: Piezoelectric bimorph / piezoelectric unimorph (planar deformation element) 10: Metal disk 11, 12: Piezoelectric plate 3: Clamp leg 2, 20, 21, 22: Weight

Claims (5)

[Claims] 1. A plane deforming element whose curvature changes with an applied voltage, a weight fixed to one of a center portion and an outer peripheral portion of the plane deforming element, and a weight fixed to the other of the center portion and an outer peripheral portion of the plane deforming element. An intra-hole moving device comprising: a leg portion that is held and abuts an inner wall surface that forms a peripheral hole; and a control unit that supplies a controlled waveform applied voltage to the planar deformation element. 2. The plane deformable element is a piezoelectric unimorph or a piezoelectric bimorph composed of a flat plate made of a spring elastic material and a piezoelectric plate which is a plate-shaped piezoelectric body bonded and fixed to at least one surface of the flat plate. Item 1. The hole moving device according to item 1. 3. The hole moving device according to claim 2, wherein the flat plate is a disk made of a metal material that also serves as an electrode of the piezoelectric plate. 4. The in-hole moving device according to claim 1, wherein the leg portion is formed of a plurality of clamp legs made of a spring elastic material. 5. The in-hole moving device according to claim 4, wherein the clamp legs are provided on both surfaces of the plane deformation element, respectively.