JPS62159819A - Microdisplacement actuator type friction brake - Google Patents

Abstract

PURPOSE:To achieve the miniaturization of a brake and the reduction in electric power consumption by making up a frictional force eliminating means of a high-power microdisplacement type actuator such as piezoelectric elements, magnetostrictive elements, or the like; a displacement magnifying lever which magnifies the displacement thereof; and a distance retaining mechanism which keeps the distance between the actuator and the acting part of the generated force. CONSTITUTION:A torsion bar 8 is fixed to a supporting frame 9 so that a braking force is generated between a rotating body 1 and a friction member 2 via a displacement magnifying lever 5, a pressing member 7, and the friction member 2. On the other hand, an actuator 3 made up of laminated type piezoelectric ceramic elements is fixed on the middle part of the first link 13 which restricts the amount of displacement by the pin 11 of the magnifying lever 5 and a slotted hole 12, and is formed to press the surface on the side of the pin 16 for links 14, 15 which are approximately at right angles to each other. Accordingly, being controllable by the applied voltage of the actuator 3, the braking force to the rotating body 1 becomes constant depending on the intrinsic torque of the torsion bar 8, and a secure brake control can be enabled by a compact structure and with less electric power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a friction brake using a powerful minute displacement element as an actuator.

(Prior art) For example, I? which applies an ilJ motion to a rotating body (various motors, rollers, etc.)? l Friction brake is usually attached to the shaft i! A brake shoe (pressing member) is pressed against a braking brake disc or brake drum (friction member) to generate frictional force (braking force). Braking force is generated by pushing or pulling force from torsion bars and coil springs, and the force acts so that the brake is applied at all times, and when the rotating body is moved, an actuator is activated to remove the braking force. I'm getting to work. In addition, it operates in the opposite way to the above, in other words, no braking force is applied at all times, and the pressing member presses the friction member to generate braking force only when brake control is performed as necessary. There are some things.

By the way, actuators that use electromagnetic force, hydraulic pressure, etc. are generally used to remove the brake h (or apply braking force) against the pressing force or tension caused by a torsion bar or coil gradient. .

[Problem to be solved]

As mentioned above, the conventional l! There are friction bushing brakes, brakes that use magnetic force (electromagnetic brakes), and hydraulic pressure as an actuator, but all of them have complicated mechanisms and have the problem that the brake part cannot be made compact. Also, those using electromagnetic force are l /
There is a problem of high J consumption and heat generation, and those using hydraulic pressure have problems such as requiring a hydraulic power source and two hydraulic cabinets.

Furthermore, if the pressing member is worn out, rl! Since the distance between the ts member and the pressing member changes, there is a problem in that the braking force changes and reliable brake control becomes impossible.

The present invention was made to solve the above-mentioned problems, and the entire brake mechanism can be configured compactly, consumes less power, has a quick response, and, furthermore,! 9. Even if the distance between the IrfA member and the pressing member changes, the braking force does not change and the brake control is stable and reliable. 11! Using a powerful minute displacement actuator! The purpose is to provide a friction brake.

(Means for Solving the Problems) To achieve the above object, II! of the present invention! Although piezoelectric elements, magnetostrictive elements, etc. can be used in friction brake actuators, piezoelectric elements have the property of expanding and contracting when a voltage is applied, and recently there has been an application of this property as an actuator (displacement element). It is expanding in various fields, and various devices are commercially available for each purpose.

In the examples of the present invention, a laminated piezoelectric ceramic element was used which has excellent characteristics such as being able to obtain a large load pressure, quick response to displacement, and being able to obtain a desired amount of displacement.

Note that barium titanate and lead zircotitanate are generally used as piezoelectric ceramics.

For example, when using a 10x 10x 18 (unit: n) prism, the displacement will be 16μ#l/'100VDG.At this time, if force is applied to compress it, the displacement will decrease and stress will be generated in proportion to the force. However, if this displacement is compressed and made into an O string, a generated horn of 350 kg/c can be obtained.

As described above, even if the laminated piezoelectric ceramic element is small, it generates a large stress and can be used satisfactorily as an actuator for a friction brake. However, since the amount of displacement is small, it is necessary to provide a mechanism to enlarge this amount of displacement depending on the size of the brake.

The spacing holding mechanism is attached to the support frame and the displacement magnifying lever of the pressing member, and the support frame is installed centered on the l! The actuator is positioned on the #11 link and the first link, which are interlocked so that the pressing member can rotate, and the actuator is attached to the displacement magnifying lever of the support frame and the pressing member. The support frame is attached to a second link that is rotatably interlocked with the pressing member so as to maintain a constant distance from the actuator located on the first link with the support frame as the center.

The specific structure of the powerful minute displacement actuator type friction brake of the present invention will be explained in detail in the embodiments to be described later.

(For f\') If a piezoelectric element is used as an actuator, the friction brake of the present invention can be operated simply by applying a voltage to the actuator. Note that since the amount of displacement of the piezoelectric element changes almost linearly depending on the magnitude of the applied voltage, the braking force can be adjusted by changing the applied voltage.

Further, the distance between the actuator and the actuator generating force acting section can be maintained at a constant value.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and is a lateral g1 explanatory diagram of a minute displacement actuator type** brake. The minute displacement actuator type friction brake of the first embodiment shown in the figure is applied to a rotating body (for example, a motor 1) which is an object to be controlled.
, a friction member (brake drum or brake disc) 2 attached to the rotating body 1, a laminated piezoelectric ceramic actuator (hereinafter referred to as "actuator") 3 configured using laminated piezoelectric ceramic elements, and an actuator 3. a voltage application terminal 4, a displacement magnifying lever 5 that magnifies the amount of displacement of the actuator, a hinge (fulcrum) 6 that supports one end of the displacement magnifying lever 5, and a pressing member ( brake shoe)7
One end is attached and fixed to the hinge 6 of the displacement magnifying lever 5, and the other end (j is fixed to the support frame 9 and uses torsional force to press the pressing member 7 against the friction member 2 to generate braking force. 1-1 housing bar 8 and a support frame (frame) 9 are formed in a U-shaped cross section, and one end side is rotatably attached to the bin 10 of the support frame 9, and the other end is attached. The first link 1 slides so as to be restricted by a long hole 12 formed in the displacement magnifying lever 5 so that the bottle 11 is inserted therethrough, and interlocks with the displacement magnifying lever 5.
3, the actuator 3 is fixed to the middle part side of the first link, and one end side of the link 14 and the link 15 is inserted through a pin 16, so that the link 14 and the link 15 are formed to be rotatable around the pin 16. The other end of the link 14 is inserted into a bin 17 provided on the displacement magnifying lever 5 , and the other end of the link 15 is inserted into a bin 18 provided on the support frame 9 .
and a second link 19 whose surface on the side of the actuator presses the top surface of the actuator and which operates in conjunction with the displacement magnifying bar 5. Note that one end of the torsion bar 8 is fixed to a support frame (frame) 9.

The torsion bar 8 constantly presses the tip of the displacement magnifying lever 5 toward the rotating body 1, and generates a braking force between the pressing member 7 and the stay member 2.

When operating the rotating body 1, a predetermined voltage is applied to the voltage application terminal 4, the actuator 3 is operated, and the displacement magnifying lever 5 is applied to the force of the torsion bar 8 via the link 14 of the first link 19. The pressing member 7
A gap is provided between the friction member 2 and the friction member 2. The position of the displacement magnifying lever 5 is determined by the force generated by the actuator 3, and can be controlled by the applied voltage.

When applying a brake to the rotating body 1 during operation, the voltage applied to the actuator 3 is gradually lowered or turned off.

If the actuator 3 contracts due to voltage reduction or voltage de-energization and a gap is created between the actuator 3 and the member 14.15, the torsion bar 8 will move until it presses the pressing member 7 against the friction member 2 due to its inherent torque. bar 5
Rotate. This pressing force that generates a brake on the rotary body 1 has a characteristic that it has a constant value due to the above-mentioned inherent torque, regardless of the amount of wear of the pressing member 7.

FIG. 2 is a configuration explanatory diagram showing a state in which the pressing member of the minute displacement actuator type @friction brake in the first actual travel example is worn out.

As the pressing member 7 wears out, the displacement magnifying lever 5 moves by an amount indicated by the arrow in the figure.

When the wear of the pressing member 7 increases, the torsion bar 8 pushes down the displacement magnifying lever 5 by the amount of wear, and the pin 11 provided on the displacement magnifying lever 5 lowers. Bin 17 is also moved. As a result, the first link 13 slides by an amount of wear m due to the long hole 12 formed in the bottle 11 and the link 13 around the bottle 10 provided in the support frame 9, and as a result, the first link 13 slides toward the middle part side. The fixed actuator also moves.

Also, since the bin 17 also moves, the second link 19 also moves to the bin 1.
7. It is moved and deformed using the bottle 18 as a fulcrum so that it is always in contact with the actuator 3 or maintains a constant gap. Geometrically, bin 16 is always on the straight line connecting bins 11 and 10.

Therefore, even if the pressing member 7 wears out, it is possible to maintain the height of the actuator 3 fixed to the first link 13 so that it is in contact with the link 19 or maintains a constant gap. It has the feature that the length of the actuator 3 can be kept constant at all times. Further, the length of the actuator 3 is controlled to maintain the pressing force between the friction member 2 and the pressing member 7 at a constant set value.

FIG. 3 is a perspective view of the first embodiment.

In the figure, bottle 11. Bin 17 is displacement magnification lever 50
Although the support frame 9 is positioned at the front in the drawing, it is needless to say that it is not limited to this position and can be changed as appropriate depending on the position and shape of the support frame 9, etc.

FIG. 4 is a structural explanatory diagram of a second practical example of the present invention. In the figures, the same reference numerals as those mentioned above indicate the same or equivalent parts. What is different from the first embodiment (10th) is a connecting member 20 that connects the second link 19 and the hinge 6.
, the actuator 3 is fixed to the other end of the communication member 20 , and the O-ra 21 is provided to the tip of the actuator 3 , and the displacement generated when the second link 19 is displaced is fixed to the first It is in contact with the link 13 or moved at a certain gap. The configuration and operation of other parts are the same as in the first embodiment. The structure of this embodiment is better than that of FIG. 1 because the displacement amount of the second link 19 can be controlled by the roller 21 more precisely and without the need for unnecessary force, so even if the pressing member 7 wears out, the friction member 2 The distance between the press member 7 and the pressing member 7 can be more accurately maintained at a constant set value. The roller 21 may be a spherical projection.

In the embodiments described above, all the actuators are used to remove the braking force, but on the contrary, it is also possible to use them in a n-shaped configuration that generates brake horns. In addition, each drawing shows the rotating body i! ilJ moving I
'Lj! Although a friction brake main brake is shown, it goes without saying that the present invention is not limited to a rotating body, but can also be applied to braking an object moving in a straight line.

(Effects) As explained above, the friction brake of the present invention utilizes the displacement and large force generated by a minute displacement actuator such as a laminated piezoelectric element, so the entire structure can be made compact, and the friction brake of the present invention can be made compact. There will be less heat and less heat. Furthermore, since the response speed is very fast, it is suitable for application to various variable speed/deceleration mechanisms.

Furthermore, since it is equipped with a spacing maintenance mechanism even if the position of the pressing member changes, the actuator spacing can always be maintained at a constant set value even if the spacing between the friction member and the pressing member changes. The displacement and large force generated by the piezoelectric element can be effectively transmitted, and no change occurs in the play kino J, allowing more reliable brake control.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram of a first practical example of a minute displacement actuator type friction brake of the present invention, FIG. 2 is a structural explanatory diagram of a first embodiment of a minute displacement actuator type friction brake of this invention, and FIG. is a perspective view of the first embodiment of the minute displacement actuator type 1IIrIA brake gear of this invention, the fourth factor is a structural explanatory diagram of the second embodiment of the minute displacement actuator type friction brake of this invention, and FIG. FIG. 2 is a structural explanatory diagram of a second embodiment of a displacement actuator type friction brake. 1...Rotating body, 2...Friction member, 3...Laminated piezoelectric ceramic actuator,
5... Displacement magnification lever, 7... Pressing member, 8... Torsion bar, 9... Support frame, 13...・First link, 19...Second link, 20...Connecting member, 21...Roller. Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A friction member that is attached to a controlled object and interlocks with the object, a pressing member that presses the friction member to generate a frictional force, and means for pressing the pressing member against the friction member. , a friction brake for braking comprising means for pushing back the pressing member to remove frictional force, the means for removing the frictional force being a powerful micro-displacement actuator such as a piezoelectric element or a magnetostrictive element. , a displacement magnification lever that magnifies the displacement of the actuator; and a distance between the actuator and the actuator generating force acting portion is maintained at a constant set value even if the arrangement position of the pressing member provided on the displacement magnification lever changes. A minute displacement actuator type friction brake, characterized in that it is configured with a spacing holding mechanism. 2. The minute displacement actuator type friction brake according to claim 1, wherein the actuator is a laminated piezoelectric ceramic actuator that expands and contracts in accordance with applied voltage. 3. The distance holding mechanism is provided between the displacement magnifying lever and the support frame, and the actuator maintains the same height with respect to the displacement magnifying lever even if the position of the pressing member changes; Claim 1, which is a link mechanism that transmits expansion and contraction of the actuator to the displacement magnification lever.
The minute displacement actuator type friction brake according to Items 1 and 2. 4. The controlled object is a rotating body, the friction member is a brake drum or a brake disc attached to the shaft of the rotating body, and the means for pressing the pressing member against the friction member is a coil spring or a torsion bar. A minute displacement actuator type friction brake according to any one of claims 1 to 3. 5. The link mechanism includes a first link that is attached to the support frame and the displacement magnifying lever of the pressing member and interlocks so that the pressing member can rotate around the mounting position of the support frame; The actuator is attached to the displacement magnifying lever of the support frame and the pressing member, and the actuator, which is positioned on the first link with the support frame attachment position as the center, is centered on the support frame attachment position so as to always maintain a predetermined distance. 4. The minute displacement actuator type friction brake according to claim 3, further comprising a second link rotatably interlocked with the pressing member.