JPS63285339A - Contact breaker - Google Patents

Abstract

PURPOSE:To provide a small and inexpensive contact breaker such as a brake, clutch or the like by bringing a wire-like shape memory alloy which is held by a first material at the one portion thereof and wound by a second material in press contact with the second material when the shape memory alloy tends to return into the memorized length. CONSTITUTION:On the part of the outer periphery of a rotary body 3 fixed on a rotating shaft 2 a wire-like shape memory alloy 8 made of Ti-Ni alloy is wound and the both ends thereof are fixed with a fixing fitting 4 and a contact fitting 6. As the shape memory alloy 8 tends to return into the memorized length, it is brought in press contact with the rotary body 3 while in the condition where the shape memory alloy 8 is elongated to a certain degree it is brought in light contact with the rotary body 3. When current is not applied, the alloy 8 becomes at the circumference temperature and is brought in light contact with the outer periphery of the rotary body 3 so as not to exert a braking force to the rotation. When current is applied, the alloy 8 is heated up to the range of a predetermined temperature and tends to return into a short length so as to be in press contact with the rotary body 3, thus braking force being generated to the rotation. Therefore, it is possible to miniaturize the device with a small structure and reduce a production cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disconnecting device that mechanically connects and disconnects between a movable body and a fixed body, or between movable bodies, such as a brake or a clutch.

[Problems to be solved by conventional technology and invention]

BACKGROUND ART Various types of brakes and clutches have been developed in the past, but all of them have problems in that they are large in size and expensive to manufacture.

[Purpose of the invention]

The present invention was made in order to solve the above-mentioned conventional problems, and provides a disconnecting device for brakes, clutches, etc., which has a very simple structure, can be made compact, and is inexpensive to manufacture. The purpose is to provide.

[Means for solving problems]

The disconnection device according to the present invention includes a first object and a second object that move relative to each other, and a wire-like shape memory wire that is partially held by the first object and hung on the second object. The shape memory alloy is such that when the shape memory alloy attempts to return to its memorized length, it comes into tight contact with the second object.

C action] When the shape memory alloy is not heated, it is in a state of elongation deformation and does not come into tight contact with the second object, and the relative relationship of the second object to the first object changes. Allow free movement.

However, when heated to a predetermined temperature range by electricity, etc., the shape memory alloy generates a shape recovery force, tries to return to its short memorized length, and comes into tight contact with the second object, causing the first object to Either the second object is not allowed to move relative to the second object, or a resistance force is generated against the relative movement.

Therefore, when one of the first and second objects is fixed, a brake function is performed, and when both the first and second objects are moving objects, a clutch function is performed.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

1 and 2 show a first embodiment of the present invention, which is an example in which the present invention is applied to a brake.

In this embodiment, a rotating shaft 2 driven by a drive device (not shown) is rotatably supported on the support 1, and a rotating body 3 is fixed to the rotating shaft 2. A fixture 4 and a contact support 5 are fixed to the support 1, and contacts 6 and 7 are attached to the contact support 5. The contact 6 has a plate-shaped portion 6a made of a highly springy conductor, and a convex portion 6b made of a conductor with a convex surface provided at the tip of the plate-shaped portion 6a. The contact 7 consists only of a plate-shaped portion made of a conductor with high spring properties. The convex portion 6b of the contact 6 and the tip of the contact 7 are pressed against each other by the elasticity of the plate portion 6a and the contact 7 and are in contact with each other when no external force is applied.

A shape memory alloy 8 made of a wire-shaped Ti-Ni alloy is wound around a part of the outer periphery of the rotating body 3, and one end of this shape memory alloy 8 is fixed to the fixing metal fitting 4. The other end is fixed to the tip of the plate-like portion 6a of the contact 6. Here, the shape memory alloy 8 memorizes a relatively short length, and when it tries to return to the memorized length, it comes into tight contact with the rotating body 3, but it stretches and deforms to some extent. In the state where it is receiving the force, it comes into light contact with the rotating body 3.

In FIG. 1, reference numeral 9 denotes a power source, one pole of which is connected to the contact 7, and the other pole connected to the fixture 4 via a switch 10. In addition, although the power supply 9 is shown as a DC power supply in the figure, this power supply 9 may be an AC power supply or a pulse power supply (this situation also applies to other embodiments to be described later). are the same).

Next, the operation of this embodiment will be explained.

When the switch 10 is open, the shape memory alloy 8 is not energized and the alloy 8 is at ambient temperature (normal temperature).
It has become. Therefore, the alloy 8 is in light contact with the outer circumference of the rotating body 3 while being subjected to elongation deformation.
No braking force is applied to the rotation of.

However, when the switch 10 is closed, a current flows through the path of power supply 9 - switch l - fixture 4 - shape memory alloy 8 - contact 6 - contact 7 - power supply 9, and shape memory alloy 8 is heated by Joule heat. .

As a result, the shape memory alloy 8 is heated to a predetermined temperature range, generates a shape recovery force, and comes into tight contact with the rotating body 3 in an attempt to return to the memorized short length. Therefore, when the rotating body 3 is being rotated, the switch 10
When closed, the shape memory alloy 8 comes into tight contact with the rotating body 3 as described above, thereby applying a brake to the rotating body 3.

In addition, as described above, when the shape memory alloy 8 comes into tight contact with the rotating body 3 and frictional heat is generated between the two, the shape memory alloy 8 is further heated by this frictional heat, resulting in an even greater braking force. occurs.

In addition, in this embodiment, when the switch 10 is closed and braking is started, the contact 6 is pulled by the shape memory alloy 8 and is slightly bent diagonally upward to the left in FIG.
A part of the shape recovery force of is absorbed by the elasticity of the contact point 6, so
It is possible to prevent the braking force applied to the rotating body 3 by the shape memory alloy 8 from increasing rapidly, and to reduce the impact at the start of braking (note that even if the contact point 6 is slightly bent, the contact point 7 will follow this and the contact point Since the contact between 6 and 7 continues to be maintained, the current supply to the shape memory alloy 8 continues).

In addition, in this embodiment, when an excessive force is applied to the shape memory alloy 8 during braking, the contact 6 is largely bent due to the elasticity of the plate-like portion 6a of the contact 6 and separated from the contact 7, and the shape memory alloy 8 Since no current flows through the shape memory alloy 8, the shape memory alloy 8 loses its shape recovery ability and is elongated and deformed. As a result, it is possible to prevent the shape memory alloy 8 from being cut due to excessive force during braking.

3 and 4 show a second embodiment in which the present invention is applied to a brake. In this embodiment, a rotating body 22 is fixed to the rotating shaft 21 . 23 is a wire-like shape memory alloy similar to the above example; 1. This shape memory alloy 23
A hole 24a provided near one end of a belt-shaped friction material 24 made of a relatively flexible material with high frictional force is inserted into the friction material 24.
from the inner surface side to the outer surface side, further penetrates the hole 24b provided near the other end of the friction material 24 from the outer surface side to the inner surface side, and is wrapped around the rotating body 22 via the friction material 24. It is being Both ends of the shape memory alloy 23 are fixed to a fixed body (not shown).

In this embodiment as well, the shape memory alloy 23 memorizes a relatively short length, and when it tries to return to the memorized length, it comes into tight contact with the rotating body 22 via the friction material 24. However, when it is stretched and deformed to some extent, it comes into light contact with the rotating body 22 via the friction material 24.

25 is a power source, one pole of this power source 25 is electrically connected to one end of the shape memory alloy 23, and the other pole is electrically connected to the other end of the shape memory alloy 23 via a switch 26.

Also in this embodiment, when the switch 26 is open, the shape memory alloy 23 is not energized;
is at ambient temperature (assumed to be room temperature). Therefore, the alloy 23 is in light contact with the outer circumference of the rotating body 22 via the friction material 24 while being subjected to elongation deformation, and does not exert a braking force on the rotation of the rotating body 22.

However, when the switch 26 is closed, a current flows in the path of power supply 25 - switch 26 - shape memory alloy 23 - power supply 25, and shape memory alloy 23 is heated by Joule heat. As a result, the shape memory alloy 23 is heated to a predetermined temperature range, generates a shape recovery force, and comes into tight contact with the rotating body 22 via the friction material 24 in an attempt to return to the memorized short length. Become. Therefore, if the switch 26 is closed while the rotating body 22 is being rotated, the rotating body 22 will be braked.

In this embodiment, the braking force can be increased by bringing the shape memory alloy 23 into contact with the rotating body 22 through the friction material 24 made of a material with high frictional force, rather than directly contacting the rotating body 22. can.

FIG. 5 shows a third embodiment in which the present invention is applied to a brake.

In this embodiment, a rotating body 32 is fixed to a rotating shaft 31 . On the outer periphery of this rotating body 32, a wire-like shape memory alloy 33 similar to those in each of the above embodiments is placed.
The three pieces are wrapped around each other so that they intersect. In this embodiment as well, the shape memory alloy 33 memorizes a relatively short length, and when it tries to return to the memorized length, it comes into tight contact with the rotating body 32. When it is stretched and deformed to some extent, it comes into light contact with the rotating body 32.

34 is a power source, one pole of this power source 34 is electrically connected to one end of the shape memory alloy 33, and the other pole is electrically connected to the other end of the shape memory alloy 33 via a switch 35.

In this embodiment as well, a braking effect can be obtained in the same manner as in each of the embodiments described above.

FIG. 6 shows a fourth embodiment in which the present invention is applied to a brake. Reference numeral 42 denotes a rotating body, and a wire-shaped shape memory alloy 43 similar to those in each of the above embodiments is wound around the rotating body 42 in a spiral shape. In this embodiment as well, the shape memory alloy 43 memorizes a relatively short length, and when it tries to return to the memorized length, it comes into tight contact with the rotating body 42. When it is stretched and deformed to some extent, it comes into light contact with the rotating body 42.

44 is a power source, one pole of this power source 44 is electrically connected to one end of the shape memory alloy 43, and the other pole is electrically connected to the other end of the shape memory alloy 43 via a switch 45.

In this embodiment as well, the braking effect can be obtained in the same manner as in each of the embodiments described above.

7 and 8 show a fifth embodiment of the present invention, and this embodiment is an example in which the main clutch is applied to a clutch.

In this embodiment, the first rotating shaft 51 is integrally provided with a first rotating body 52 having a cylindrical shape with a bottom. Inside this first rotating body 52 is a short cylindrical second rotating body 5.
3 is accommodated, and this second rotating body 53 is integrally provided at one end of the second rotating shaft 54. and,
The second rotating body 53 and the second rotating shaft 54 are coaxial with the first rotating body 52 and the first rotating shaft 51.

A wire-like shape memory alloy 55 similar to those in each of the above embodiments is wound around the second rotating body 53 so that the alloys 55 intersect with each other, and both ends of the alloy 55 are It is fixed to the first rotating body 52. In this embodiment as well, the shape memory alloy 55 memorizes a relatively short length, and when it tries to return to the memorized length, it comes into tight contact with the second rotating body 53. However, when it is stretched and deformed to some extent, it comes into light contact with the second rotating body 53.

A slip ring 5 is provided on the outer peripheral surface of the first rotating body 52.
6.57 are fixed and these slip rings 5
Brushes 58 and 59 attached to a fixed body (not shown) are in contact with 6.57.

In FIG. 8, reference numeral 60 denotes a power source, one pole of which is electrically connected to the brush 59, and the other pole electrically connected to the brush 58 via a switch 61.

In this embodiment, when the switch 61 is open, the shape memory alloy 55 is not heated and no shape recovery force is generated, so it only lightly contacts the second rotating body 53. The second rotating body 53 is in a state where it can freely rotate relative to the first rotating body 52.

However, when switch 61 is closed, power supply 60 - brush 59 - slip ring 57 - shape memory alloy 55 - slip ring 56 - brush 58 - switch 61 - power supply 6
As the current flows through the path 0 and the shape memory alloy 55 is heated to a predetermined temperature range, the alloy 55 generates a shape recovery force and tries to return to the memorized short shape, and the second rotating body 53 comes into tight contact with the outer circumferential surface of the Thereby, the first rotating body 52 and the second rotating body 53 will rotate integrally from then on.

Moreover, when the switch 61 is opened again, the shape memory alloy 55 cools down, loses its shape recovery force, and undergoes elongation deformation, so that the second rotary body 53 and the first rotary body 52 are free to rotate relative to each other again. state.

Therefore, in this embodiment, by opening and closing the switch 61, the first rotating shaft 51 side and the second rotating shaft 54 side can be connected and disconnected, and the clutch function can be achieved.

FIG. 9 shows a sixth embodiment of the present invention, and this embodiment is also an example in which the present invention is applied to a clutch.

In this embodiment, a round bar-shaped second rotating body 72 coaxially penetrates a cylindrical first rotating body 71 . A wire-shaped shape memory alloy 73 similar to those in each of the above embodiments is spirally wound around the second rotating body 72, and both ends of this alloy 73 are fixed to the first rotating body 71. has been done. In this embodiment as well, the shape memory alloy 73 memorizes a relatively short length, and when it tries to return to the memorized length, it comes into tight contact with the second rotating body 72. However, when it is stretched to some extent and deformed,
It is adapted to lightly contact the second rotating body 72.

74 is a power source, one pole of this power source 74 is electrically connected to one end of the shape memory alloy 73 via a brush and a slip ring (not shown), and the other pole is connected to a switch 75 and a brush and a slip ring (not shown). It is electrically connected to the other end of the shape memory alloy 73 via a slip ring or the like.

In this embodiment as well, in the same manner as in the previous embodiment, the switch 75 is opened and closed to energize and stop the energization of the shape memory alloy 73, causing the shape memory alloy 73 to undergo contraction (recovery of its shape in the length direction) and elongation deformation. By doing so, the first rotating body 71 and the second rotating body 72 can be disconnected.

In addition, in the above embodiment, an example was shown in which the present invention is applied to brakes and clutches related to rotational motion, but the present invention can also be applied to disconnection devices such as clutches and brakes for motion other than rotational motion such as linear motion. It is.

〔Effect of the invention〕

As described above, the disconnection device according to the present invention has an excellent effect in that it has a very simple structure, can be made compact, and can be manufactured at low manufacturing cost. It is something that can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a first embodiment of the present invention, Fig. 2 is a plan view showing the first embodiment, Fig. 3 is a front view showing a second embodiment of the invention, and Fig. 4 is a front view showing a second embodiment of the invention. FIG. 5 is a plan view showing the second embodiment, FIG. 5 is a front view showing the third embodiment of the invention, FIG. 6 is a perspective view showing the fourth embodiment of the invention, and FIG. 7 is a perspective view showing the fourth embodiment of the invention. FIG. 8 is a sectional view taken along the line ■--■ in FIG. 7, and FIG. 9 is a perspective view showing the sixth embodiment of the present invention. 3.22, 32, 42.52, 53, 71.72...
Rotating body, 8.23.33, 43, 55.73...shape memory alloy.

Claims (1)

[Claims] A first object and a second object that move relatively, and a shape memory alloy in the form of a wire that is partially held by the first object and hung on the second object. An interrupter comprising: wherein the shape memory alloy comes into tight contact with the second object when attempting to return to the memorized length.