JPS60213275A - Brake device - Google Patents

Abstract

PURPOSE:To enhance the response of a brake device by displacing the first piezoelectric stack secured to a brake element by applying a voltage to the stack in the state that the second and third piezoelectric stacks are secured under displacing operation, thereby reliably performing the stopping operation. CONSTITUTION:A brake device body 10 and the first, second bodies 12, 14 are oppositely bonded to have a horizontal recess 16 and vertical first and second recesses 18, 20. A circular recess 22 is formed between the recesses 18 and 20, and a piston rod 24 which constructs an actuator is movably engaged therewith. The first-fourth piezoelectric stacks 26-28, 38-40 are arranged oppositely to the rod 24, and the first-second brake elements 34-36, 46-52 are further secured. Thus, the prescribed voltage is applied to the first stack 26 in the state that the second and third stacks 28, 38 are secured thereto, and the brake element is pressed in contact with the rod 24 to brake it.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake device, and more particularly, it utilizes a plurality of piezo stacks that are displaced in a predetermined direction when a voltage is applied, and furthermore, the present invention relates to a brake device that uses a plurality of piezo stacks that are displaced in a predetermined direction when a voltage is applied, and that It opens to a brake system that incorporates an adjustment mechanism to adjust flare.

For example, when attempting to position a 1° actuator driven using hydraulic pressure or pneumatic pressure, it is necessary to brake the actuator in the middle of its operating range. In this case, in the conventional device, the positioning operation is ensured by stopping the supply of the pressure fluid.

For example, in a reciprocating air cylinder, when trying to stop the piston mid-stroke, air at a predetermined pressure is prevented from being introduced from one boat, and the brake is applied by the frictional force between the piston and the inner wall of the cylinder. It consists of Therefore, it is necessary for a certain amount of time U to elapse after the introduction of air at a predetermined pressure is stopped until the rear piston is stopped by the frictional force as described above. That is, when attempting to stop the piston at a desired position, an accurate braking operation can only be obtained by operating the piston in consideration of the elapsed time until the piston stops due to the frictional force being generated. Therefore, this type of actuator has the disadvantage of extremely poor responsiveness for positioning control. Moreover, when trying to restart this actuator, the pressure medium has to be supplied again from the boat formed in the cylinder, and in fact, it still takes a predetermined time period before the piston is displaced in the cylinder. Requires progress. In the end, when an actuator attempts to perform braking using fluid pressure, a fatal drawback arises in that the responsiveness is inferior to that of electrical braking. Therefore, in order to eliminate the above-mentioned disadvantages, it is best to incorporate an electric braking mechanism into the actuator that utilizes fluid pressure. However, a energized electrical braking mechanism requires a relatively large structure.

In particular, an actuator that is incorporated into a robot or the like and rotates an arm is required to be miniaturized, so an electric braking mechanism for commuting to and from school is not necessarily a braking device that meets the needs.

Therefore, as a result of intensive research and ingenuity, the present inventors focused on a piezo stack that displaces in a predetermined direction when a voltage is applied with a fixed polarity. It has been shown that an actuator that can perform arbitrary stop braking in the middle of a stroke can be obtained with a relatively small configuration.

In this case, when the braking element becomes worn out due to repeated use, a different vinyl brake is prepared in advance.
If the piezo stack that holds the braking element is clamped by this piezo stack, thereby ensuring that the braking element always maintains a constant flare with respect to the piston rod, extremely accurate braking operation can be achieved. An actuator is obtained.

Therefore, an object of the present invention is to ensure that the stopping operation is performed reliably and to have extremely high responsiveness to restarting, and to prevent a constant flare between the braking element and the actuator body even when the braking element wears out. It is an object of the present invention to provide a brake device for an actuator, which can be secured in terms of performance, has an increased service life, is structurally simple and compact, and can be manufactured at low cost.

In order to achieve the above object, the present invention provides a braking element that is provided adjacent to a driven body that rotates or reciprocates, and a first piezo stack consisting of a plurality of piezo elements is fixed to the braking element. Furthermore, at least one set of second and third vinyl tanks are provided that are displaced toward the first piezo stack, and the first piezo stack is fixed to the first piezo stack under the second and third displacement operations. The braking device is characterized in that a predetermined voltage is applied and the braking element is displaced relative to the driven body, thereby bringing the braking element into pressure contact with the driven body and braking the driven body.

Next, preferred embodiments of the brake device according to the present invention will be described in detail with reference to the accompanying drawings.

First, in FIG. 1, reference numeral 10-C indicates the main body of the brake device. This brake device main body lO is a first body 1
2 and a second body 14. The first body 12 and the second body 14 are joined to face each other, thereby forming a horizontally extending recess 16 in FIG. 1, a vertically extending first recess 18, and the first vertical Recess 1
A second recess 20 spaced from 8 is defined. A circular recess 22 is formed in an intermediate portion between the first vertical recess 18 and the second vertical four parts 20. A piston rod 24 constituting an actuator is movably fitted into this circular recess 22 . A first vinyl storage tank 26 is disposed in one example of the horizontal recess 16 opposite to the piston rod F24, and a second piezo stack 26 is disposed adjacent to the piston rod 24 on the opposite side of the first piezo stack 26. 28
will be placed.

It is held on the piston rod 24 side by a first elastic member 30 disposed within the portion 16, and a first braking element 34 is fixed to the tip end thereof. On the other hand, the second vinyl cis tank 28 is similarly held by a second elastic member 32 disposed within the horizontal recess 16, and a second braking element 36 is fixed to the tip thereof. The first braking element 3
4. The second braking element 36 may be made of a material having a high coefficient of friction, and may be made of a material containing rubber or carbon fiber, for example.

Next, the first vertical quadrant 18 includes a third piezo stack 38.
and a fourth piezo stack 40 are arranged. The third piezo stack 38 and the fourth piezo stack 40 are
They are arranged with a piezo stack 26 in between. Similarly, a fifth piezo stack 42 is installed in the second vertical recess 20.
and a sixth piezo stack 44 are arranged so as to sandwich the second and rainbow stutter 28 therebetween. A braking element 46, 48, 50, 52 made of the same material as the first braking element 34 and the second braking element 36 is disposed at the tip of each piezo stack 38, 40, 42, 44. . As can be seen from the figure, the piezo stacks 26, 28.
A power line is connected to 38, 40, 42, and 44, and this power line is configured to supply a predetermined voltage to each piezo stack from a DC power source (not shown).

Therefore, the operation and effects of the brake device configured as described above will be explained.

First, the first braking element 34 and the second braking element 36 are each held with respect to the piston rod 24 so as to have an appropriate flare. That is, in the school commuting state, the third piezo stack 38 and the fourth piezo stack 40 fix and hold the first piezo stack 26 under the action of a predetermined voltage. On the other hand, the fifth piezo stack 42 and the sixth piezo stack 44 also fix and hold the second piezo stack 28.

For this reason, the first braking element 34 and the second braking element 36 are spaced apart from each other by a predetermined distance from the displacing piston rod 2.
You will be facing 4.

When a brake signal is issued to the piston rod 24 in such a state, first, the third piezo stack 38
, the fourth piezo stack 40 and the fifth piezo stack 4
2. The supply of voltage to the sixth piezo stack 44 is stopped. As a result, the first piezo stack 26 is held only by the first elastic member 30. Similarly, the second piezo stack 28 is also held by the second elastic member 32. In this case, the first braking element 34 attached to the tip of the first piezo stack 26 is set to face the piston rod 24 at a predetermined distance due to the elastic force of the first elastic member 30. (Toyoi.

On the other hand, the elastic force of the second elastic member 32 is selected in the same manner as described above so that the second braking element 36 faces the piston rod 24 at a predetermined distance. Through the above process, the flare of the first braking element 34 and the second braking element 36 with respect to the piston rod 24 is adjusted.4 Next, the third piezo stack 38, the fourth piezo stack 40, the fifth piezo stack 42 and 6th
Piezo stack 44 is energized. As a result, the first piezo stack 26 that was displaced toward the piston 0' seat 24 is held again by the first elastic member 30, and the second piezo stack 26 is held in the same manner.
The second piezo stack 28 displaced in the direction of the piston rod 24 by the elastic member 32 is held by the fifth piezo stack 42 and the sixth piezo stun 44 (11; j). Piezo stack 38.40 like this
The first piezo stack 26 and the fifth piezo stack held by
A voltage is applied to the second vinyl stack 28 held by the piezo stack 42 and the sixth piezo stack 44. As a result, the first piezo stack 26 and the second piezo stack 28 are displaced with a large force toward the screw I-in rod 24 side, and press the first braking element 34 and the second braking element 36 against the piston rod 24. Therefore, piston rod 2
The reciprocating movement of the brake element 4 is prevented from displacement by the frictional resistance of the brake elements 34 and 36.

When attempting to release the piston rod 24 from such a braking state, it is sufficient to stop applying voltage of a predetermined polarity to the first piezo stack 26 and the second piezo stack 28.

As a result, the first piezo stack 26 and the second piezo stack 28 try to return to their current state, and therefore the first braking element 34 and the second braking element 36
Then, the piston rod 24 becomes movable again.

Next, FIG. 2 shows another embodiment of the brake device according to the present invention. In this embodiment, the same reference numerals as in FIG. 1 indicate the same components.

Now, in this embodiment, unlike the embodiment shown in FIG. and the second elastic member 32, the holding portion +
) A holding part key 62 having the same shape as f60 is provided. Therefore, in this practical example, the first piezo stack 38
, when the fourth piezo stack 40 is energized, it firmly holds the retainer 81; It becomes like being pinched.

With this configuration, there is no need for the first piezo stack 26 and the second piezo stack 2B to be directly held by other piezo stacks, so it is possible to obtain the effect of excellent durability.

Next, still another embodiment of the brake device according to the present invention is shown in FIGS. 3Δ to 3C. In this embodiment as well, the same reference numerals as in the above two embodiments indicate the same components.

Therefore, in this embodiment, the brake device IO includes a body 64 configured in a disc shape. A chamber 66 is formed in the body 64 formed by arranging two disc bodies facing each other, and the chamber 66 is in communication with four grooves 68 extending in the radial direction of the body 64. Therefore, inside the chamber 66 are a fan-shaped first holding member 70, a second holding member 72, a third holding member 74, and a fourth holding member 7.
6 are arranged radially, and a piezo stack and a braking element are mounted inside each holding member.

That is, the holding member 70 is equipped with a first piezo stack 78 having the same curvature as the screw thread 24, and similarly, a second piezo stack 80 is attached to the holding member 72, a third piezo stack 82 is attached to the holding part +A74, and a third piezo stack 82 is attached to the holding member 72. 7
6 is attached with a fourth vinyl stock 84. Moreover, on the piston rod 24 side of the piezo stacks 78 to 84, there is further a braking element 8 made of the same member as in the above embodiment.
6.88.90 and 92 are installed respectively. The holding unit month 70.72.74.76 configured in this way is 4
Elastic members 94,96,98 arranged in two grooves 68
and held by 100. Moreover, in this embodiment, as can be easily read from FIG.
02 and 104 are arranged, and the piezo stack 10
Braking elements 106 and 108 are attached to the distal end portions 2 and 104, respectively.

This piezo stack 102, 104 has a disc shape as seen in FIG. 3C, and its braking element 106.
108 is configured to be in contact with the holding members 70 to 76.

In the above configuration, the piezo stacks 102 and 10
4 holds the holding members 70 to 76, respectively, via braking elements 106 and 10B. In this state, the first piezo stack 78, the second piezo stack 80, and the third piezo stack 78
When a voltage is applied with a predetermined polarity to the piezo stack 82 and the fourth piezo stack 84, the first braking element 86, the second braking element 88, the third braking element 90, and the fourth braking element 92, which are attached to the tips of the piezo stack 82 and the fourth piezo stack 84, respectively, are activated. The piston rod 24 is pressed against the piston rod 24 to stop it. Of course, when it is desired to restart the piston rod 24, the application of voltage to the first to fourth piezo stacks 78 to 84 can be stopped, as in the first and second embodiments. Note that the first braking element 86 to the fourth braking element 86
If the braking element 92 is worn out due to frequent braking, the application of voltage to the piezo stack 102 and 104 is temporarily stopped and the first to fourth elastic members 94 to 1
The holding members 70 to 76 are slightly displaced toward the piston wand 24 side under the force of 000 rebound, and the Biezo star 102 is again moved.
104 may be biased and held in position to maintain a predetermined flare relative to the piston rod 24.

As described above, in this embodiment, the first embodiment, the second embodiment
Unlike the embodiment described above, the main body is configured in a disk shape.

Therefore, there is an advantage that it can be suitably incorporated into an actuator having a circular cross section, such as a cylinder type actuator or a rotary type actuator.

FIG. 4 shows another embodiment of the invention. In this embodiment, a holder 112 having a substantially U-shaped cross section is located adjacent to the rotating iron 110.
has been set up. A first piezo stack 114 and a second piezo stack 116 are disposed inside the holder 112, and a braking element 11B is attached to the tip of the first piezo stack 114, while the second piezo stack 1
A braking element 120 is similarly disposed at the tip of the brake member 16 .

The braking elements 11B and 120 are spaced apart from each other by a predetermined distance, and the holding members 122 and 124 hold the first piezo stack 114 and the second piezo stack 116, respectively, and an elastic member 126 and 12B is provided at the other end.
is held by a holding body 112. Moreover, in the vertical direction of the holding members 122 and 124, there are further a third piezo stack 130, a fourth piezo stack 132, and a fifth piezo stack 130.
Piezo star, 7th 134 6th piezo stack 136
will be placed. And the braking elements 11B, 120
A rotating disk 13 fixed to a rotating rod 110 between
Have B present.

When trying to brake the disc 13B of the rotating rod 110 in the above configuration, the first piezo stack 11
4. A voltage may be applied to the second vinyl cis tank 116 with a predetermined polarity. Of course, the piezo stack 114116, which is displaced by the application of voltage, is a braking element 118,120.
is pressed against one end surface of the disk 138 to rotate the rotating disk 138.
It acts to forcibly brake. Note that the elastic member 126
．． 128 and the third to sixth viezo stacks 130 to 136 adjust the flare of the braking elements 118 and 120 with respect to the rotating disk 13B, and function in the same manner as in the previous embodiment.

Yet another embodiment of the invention is shown in FIG.

In the figures, the same reference numerals as in the above embodiment indicate the same components.

As can be easily understood from FIG.
This is similar to the embodiment shown in the figure. However, in this embodiment, air cylinders 140 and 142 are provided in place of the first elastic member 30 and the second elastic member 32 shown in FIG. That is, the piston of air cylinder 140 holds first piezo stack 26, while air cylinder 142 holds second piezo stack 28. With this configuration, the cylinders 140 and 142 perform the same function as the elastic members 30, 32, but in this case, their displacement operation is controlled by the valve device 144, so that the cylinders 140 and 142 can operate in a more stable state. A braking action of 26.28 can be achieved. This brake device can be said to be compatible with relatively large devices.

According to the present invention, as described above, by applying a predetermined voltage to the piezo stack during the displacement of the actuator, the displacement of the driven body can be quickly and reliably braked. Therefore, when compared with the conventional actuator which uses fluid pressure to brake a driven body based on valve operation, the -Ff response is excellent and the actuator can be made smaller. Furthermore, even if the braking element itself is worn out, the attached piezo stack and elastic member, or
It is possible to adjust the tail clearance under the action of other fluid pressure mechanisms and to occupy the optimum position relative to the driven object, thereby ensuring reliable braking in any situation.

Furthermore, since the piezo stack is relatively small, for example, even if this device is incorporated into an actuator that does not move the arm of a robot, the arm itself will not feel that heavy, and on the contrary, its range of motion and movement will be reduced. The advantageous effect of being able to use a wide variety of patterns can also be obtained.

Although the brake device according to the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and modifications may be made without departing from the gist of the present invention. Of course, changes are possible.

[Brief explanation of the drawing]

The figures relate to the present invention, in which Fig. 1 is a schematic longitudinal sectional view of a brake device incorporated into a body having a rectangular cross section, and Fig. 2 shows a piezo stack held by the piezo stack shown in the brake device shown in Fig. 1. An outline of the state in which the parts are arranged! ii [Explanatory diagrams, Figures 3A to 3C are explanatory diagrams showing a state in which the braking device according to the present invention is configured in a disc shape, and Figure 4 is
FIG. 5 is a schematic explanatory diagram of the present invention apparatus for braking a single-turning disc, in which a cylinder is installed to maintain a constant tail balance of a braking element with respect to a driven object. lO...Brake device body 12.14...Body 16
．． 1 (1, 20, 22... recess 24... piston rod 26.28... vinyl system tank 30.32... elastic member 34.36... braking element 38
．． 40.42.44... Vinisys Tank 46.48.5
0.52,... Braking element 60.62... Holding member 64
...Body 66...Chamber 68...Groove 70.72.74.76...Holding member 78.80.82.84...Piezo stack 86.88
．． 90.92... Braking element 94.96.98.100... Elastic part +4102.1
04...Vinisy Cook 106.108...Braking element 110...Rotating rod 112...Holding body 114.116...Piezo stack 11B, 120...Braking element +22, +24...
Holding member 126.128...Elastic member 130.132.134.136...Vinisys tank 138...Disk 140.142...Air cylinder 144...Valve device patent applicant Sintered Metal Industry Co., Ltd.

Claims (1)

[Scope of Claims] +11 A braking element is provided adjacent to a driven body that rotates or reciprocates, a first Vinysis tank consisting of a plurality of piezo elements is fixed to the braking element, and the first
The piezo stack is provided with at least one set of second and third vinyl cisterns that are displaced in the tl direction, and the first vinyl cis tank is fixed in a state where the first piezo stack is fixed under the displacement operation of the second and third piezo stars. A brake device characterized in that the braking element is brought into pressure contact with the driven body and braked by applying a predetermined voltage to the driven body and displacing it with respect to the driven body. (2. In the device according to claim 1, the first
A piezo stack is a brake device that is installed in pairs against a driven object. (3) The brake device according to claim 1, wherein the first piezo stack is pressed against the driven body by an elastic member or a fluid pressure cylinder. (4) In the apparatus according to claim 1, the first vinyl cistern is held by a holding member, and the holding member is held by a second piezo stack or a third piezo stack to position the first piezo stack. Device. (5) In the apparatus according to claim 1, the first piezo stack is a brake device comprising stacked piezos formed in a fan shape divided into a plurality of piezos spaced apart from each other by a predetermined distance. (6) The brake device according to claim 1, wherein the second and third vinyl tanks are formed in a circular shape. (7) The brake device according to claim 1, wherein the driven body is a disc fixed to a cylinder rond or a rotating rond.