JP2528657B2 - Self-propelled linear motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is to move a linear object by moving along a linear rail, and is used for positioning tools such as NC machine tools, workpieces, and microscopes. The present invention relates to a self-propelled linear motor applied to fine feed of specimens, fine angle adjustment of an engineering mirror, and the like.

<Prior Art> In order to move a conveyed object so that it can be used for precise position adjustment, a driving body that enables a minute step amount is required.

Then, as a thing which can respond to this, Japanese Patent Application No. 54-832
As disclosed in 2, a linear step motor having a piezoelectric laminate for straight movement and a laminate for clamping has been proposed.

<Problems to be Solved by the Invention> However, in such a structure, since the clamp piezoelectric laminate is brought into contact with the corresponding wall of the straight passage and is transferred, the structure of the straight road is complicated such as a cylinder. In addition, the corresponding wall requires high parallelism and smoothness, which makes machining difficult. Also, when the passage becomes long, the occurrence of error cannot be avoided, so in the end,
There is a defect that it is not suitable when a long traveling distance is required.

It is an object of the present invention to provide a self-propelled linear motor that does not have the above-mentioned drawbacks.

<Means for Solving Problems> According to the present invention, a vibrating body that vibrates in the longitudinal direction is arranged on one sliding surface of a linear rail having a polygonal cross-section, and the vibrating body is disposed at both ends of the vibrating body at substantially the maximum swing position. And a piezoelectric laminate that is pressed against one sliding surface of the linear rail, both piezoelectric laminates expand and contract in the laminating direction in synchronization with the vibration of the vibrating body, and the two piezoelectric laminates are opposite to each other. A linear traveling body that is subjected to voltage control at expansion and contraction timing is arranged, and a transfer body is arranged on the other sliding surface of the linear rail, and the linear traveling body is arranged at the node position in the substantially central portion of the vibrating body. It is characterized in that it is connected to the transfer body via a pulling spring.

<Operation> The linear traveling body is held by the linear rail by being connected to the transfer body via a pulling spring.

Then, when the vibrating body extends, the central portion of the vibrating body is at the node position, so that both ends slightly expand and contract outward.

At this time, for example, when the piezoelectric laminate at the left end extends and comes into pressure contact with one sliding surface of the linear rail, and when the vibrating body expands when the piezoelectric laminate at the right end contracts, the piezoelectric laminate at the left end expands. Since the vibrating body is connected to the linear rail side through the body, the vibrating body extends with the pressure contact portion as a fulcrum, and the right end extends.

Next, when the piezoelectric laminated body at the left end contracts and the piezoelectric laminated body at the right end expands and comes into pressure contact with one sliding surface of the linear rail, when the vibrating body contracts, the piezoelectric laminated body at the right end expands. Since the vibrating body is connected to the linear rail side via the, the vibrating body contracts with the pressure contact portion as a fulcrum, and the left end is drawn.

Therefore, this continuation causes the linear motor to travel along the linear rail.

When the linear motor is run in the reverse direction, the expansion / contraction timing of the left and right piezoelectric laminates may be reversed corresponding to the expansion / contraction timing of the vibrating body.

<Embodiment> In FIGS. 1 and 2, reference numeral 1 denotes a self-propelled linear motor 1 of the present invention, which is mounted on a linear rail x having a rectangular cross section. Transporting body that supports the linear traveling body 2 on the lower surface side of the
15 are arranged.

The linear traveling body 2 has a rod shape along the linear rail x, and its configuration will be described.

Referring to FIG. 1, reference numeral 3 denotes a vibrating body, which is a longitudinal vibrating element composed of two annular pressure elements whose polarization directions are different from each other.
Duralumin metal blocks 5 on both sides of the 4,4 stack
a, 5b are arranged, and further, the bolt 7 is inserted in the center of each member, and the screws 8a, 8b at the upper and lower ends thereof are respectively screwed into the screws provided around the inner surfaces of the metal blocks 5a, 5b to vibrate. It is configured by sandwiching the elements 4, 4 between metal blocks 5a, 5b.

In such a structure, as shown in FIG.
Horn-shaped metal blocks 6a, 6b whose ends are reduced in diameter may be arranged on both sides of 4, 4 to amplify the vibration.

The length of each of the metal blocks 5a, 5b, 6a, 6b is such that both ends of the metal blocks 5a, 5b, 6a, 6b are 1/4 wavelength from the center position (node position) of the vibrating elements 4, 4.

At both ends of the vibrating body 2, a plurality of piezoelectric element plates polarized in the thickness direction are laminated, and piezoelectric laminates 10a and 10b in which the respective piezoelectric element plates are electrically distributed in parallel are arranged in the laminating direction. The linear rails x are fixed in conformity with the direction orthogonal to the sliding surface y.

 Next, the transfer body 15 will be described.

The transfer body 15 includes two front and rear wheels 16 and 16 placed on a sliding surface y, and a side plate 1 that rotatably connects the wheels 16 and 16.
7 and 17, the node position (central portion) of the vibration elements 4, 4 of the linear traveling body 2 and the side plates 17, 17 are attached to the spring hook piece 1.
1, 18 are provided in a protruding manner, and extension springs 19, 19 are stretched over the spring hooking pieces 11, 18. Then, the linear traveling body 2 and the transfer body 15 are urged by the pulling springs 19 and 19 toward the upper and lower sliding surfaces y and y, and the piezoelectric laminated bodies 10a and 10b are slid on the sliding surface y.
Press against.

In the above configuration, in order to move the self-propelled linear motor 1 along the linear rail x in the right direction as shown by the arrow in FIG. 1, in order to move the longitudinal vibration element 4, as shown in FIG. 4 to E ₁ si
Assuming that an alternating voltage of nωt is applied, the piezoelectric laminate 10a at the right end has f (t) = − 1, T / 2 <t <T when 0 <t <T / 2.
Then, the rectangular pulse voltage having the timing waveform of f (t) = 1 is applied to the leftmost piezoelectric laminate 10b, and the rectangular pulse voltage having the timing waveform of −f (t) is applied to the leftmost piezoelectric laminate 10b. Or
E ₂ cos .omega.t the piezoelectric stack 10a, the piezoelectric laminate 10b E ₂
A voltage of sin ωt may be applied.

As a result, the piezoelectric laminate 10a contracts and the piezoelectric laminate 10b expands in synchronization with the extension of the vibrating body 3 by the longitudinal vibrating elements 4, 4, so that the sliding surface y and the piezoelectric laminate 10b are separated from each other. When pressed, the linear traveling body 2 advances in the right direction with the piezoelectric laminated body 10a using the piezoelectric laminated body 10b as a fulcrum (see FIG.
C).

Next, in synchronization with the contraction of the vibrating body 3, the piezoelectric laminate
Since 10a expands and the piezoelectric laminate 10b contracts, the sliding surface y
The piezoelectric laminated body 10a is pressed against the piezoelectric laminated body 10a, and the linear traveling body 2 pulls the piezoelectric laminated body 10b rightward with the piezoelectric laminated body 10a as a fulcrum. (FIG. 4 c) The linear traveling body 2 is
It moves in a stepwise manner as the vibrating body 3 expands and contracts, and along with this, the transfer body 15 on the linear rail x travels to the right while rotating its wheels 16,16. Therefore, the transfer body 15
By loading or transporting the transported object w on the
It becomes possible to transfer the conveyed product w.

When the self-propelled linear motor 1 travels to the left, the expansion / contraction timing of the piezoelectric laminates 10a and 10b with respect to the vibrating body 3 may be reversed.

In FIG. 6, a linear traveling body 20 having the same structure as the linear traveling body 2 is applied in place of the transfer body 15, and the linear traveling body 20 is used.
It is a transporter itself. With this configuration, the driving force increases. Further, the conveyed object may be placed on the linear traveling body 20 or may be continuously connected.

In FIG. 7, the linear rail x has a regular triangular cross section, and the linear traveling body 30 is arranged on each sliding surface y. In such a configuration, the spring hooking pieces 31 project outward in a bifurcated manner from the central positions of the vertical vibrating elements 4, 4 respectively, and the springs 32 are hooked on the adjacent spring hooking pieces 31 around the linear rail x. By passing, the piezoelectric laminates 10a, 10b are pressed against the sliding surface y and the self-propelled linear motor 1 itself is held.

In the voltage control of the longitudinal vibration elements 4 and 4 and the piezoelectric laminated bodies 10a and 10b, an alternating current power source may be used and an alternating voltage may be generated from the direct current power source through a switching mechanism.

<Effect of the Invention> As described above, the present invention provides the linear rails by providing the piezoelectric laminates 10a and 10b on both sides of the vibrating body 3 and adjusting the expansion / contraction timing of the vibrating body 3 and the piezoelectric laminates 10a and 10b. Since the vehicle can be driven with respect to x, the rotation direction of the linear rail x can be adjusted by timing conversion, and the driving force can be adjusted by voltage control, which is easy to control and linear. The rail x has a very simple structure because it only needs to have a polyhedron cross section, and since the piezoelectric laminates 10a and 10b are elastically contacted by the extension springs 19 and 32, the sliding surface y has a high smoothness. It is easy to mold without requiring. Therefore, there is an excellent effect that it can be applied not only to minute movement control but also when a long traveling distance is required.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a self-propelled linear motor 1, FIG. 2 is a front view of the same, and FIG.
FIG. 4 is a chart showing the voltage application timing, FIG. 4 is an explanatory view showing the operation timing, FIG. 5 is a side view of the second embodiment, FIG. 6 is a side view of the third embodiment, and FIG. It is a front view of 4th Example. x; linear rail, y; sliding surface, 1; self-propelled linear motor, 2;
Linear traveling body, 3; Vibration body, 4, 4; Longitudinal vibration element, 5a, 5b, 6a, 6
b; metal block, 10a, 10b; piezoelectric laminate, 15; transfer body, 19,
32; Spring, 20, 30; Linear traveling body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michiyuki Masuda, 14-18 Takatsuji-cho, Mizuho-ku, Nagoya City, Japan Special Ceramics Co., Ltd. (56) Reference JP 63-15680 (JP, A) JP Sho 62-2546620 (JP, A) JP 61-180583 (JP, A)

Claims (3)

(57) [Claims] 1. A linear rail having a polygonal cross section, and a vibrating body vibrating in a longitudinal direction on one sliding surface of the linear rail. The piezoelectric laminates are in pressure contact with the surfaces, both piezoelectric laminates perform an expansion / contraction operation in the laminating direction in synchronization with the vibration of the vibrating body, and both piezoelectric laminates are subjected to voltage control with reverse expansion / contraction timing. In addition to arranging the linear traveling body, the transfer body is disposed on the other sliding surface of the linear rail, and the linear traveling body is connected to the transfer body via the pulling spring at the node position in the approximate center of the vibrating body. A self-propelled linear motor that is characterized by 2. The self-propelled linear motor according to claim 1, wherein the transfer body is the linear traveling body. 3. A linear rail having a triangular cross section, the linear traveling bodies being arranged on each side surface, and the linear traveling bodies being connected at node positions of the vibrating body. Traveling linear motor.