JPH07243459A - Fluid pressure brake device - Google Patents

Abstract

PURPOSE:To easily provide a device, which is constituted to prevent leakage of working fluid through a fluid chamber, at a low cost. CONSTITUTION:A hydraulic brake device 10 is provided with a brake member 16 axially displaceably arranged in a state to surround a rotary shaft 12 inside a casing 14. A radially extending friction surface 22 is formed on one end face in an axial direction of the brake member 16. An annular fluid chamber 28 to surround a rotary shaft 12 is formed between the other end face 24 in an axial direction of the brake member 16 and a casing 14. An radially extending flange part 32 is arranged on the rotary shaft 12. Working fluid is fed under a given pressure from an external feed source to a flexible container 36 arranged at the fluid chamber 28. A container 36 is expanded in a fluid chamber 28 by the pressure of working fluid and the wall of the container 36 presses the brake member 16. This constitution presses the friction surface 22 of the brake member 16 against the contact surface 34 of the flange part 32 of the rotary shaft 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure brake device, and more particularly to a fluid pressure brake device in which a friction surface is displaced in direct relation to a change in volume of a fluid chamber due to pressure adjustment of a working fluid.

[0002]

2. Description of the Related Art In various industrial equipment such as robots and machine tools, various braking devices are used for the purpose of braking, holding and positioning of operating parts. Among them, the fluid pressure brake device using the fluid pressure means as the operating means has an advantage that it generates less heat and does not magnetize the braked object such as the rotating shaft as compared with the brake device operating by the electric or magnetic means. Have. Further, the fluid pressure brake device can easily control the braking and holding forces by adjusting the pressure of the working fluid.

In this type of fluid pressure brake device, it is known that the friction surface engageable with the target surface is displaced in direct relation to the volume change of the fluid chamber due to the pressure adjustment of the working fluid. In this fluid pressure brake device, a fluid chamber is formed adjacent to a movable braking member having a friction surface, between a wall of the braking member and a casing wall of the braking device which is displaced relative to the braking member, The volume change of the chamber directly causes the displacement of the braking member. The braking member is generally biased in the opposite direction by a biasing means such as a return spring, against a bias in a predetermined direction due to fluid pressure. The conventional fluid pressure brake device of this type is used for pressing the friction surface of the braking member against the target surface against the bias of the biasing means by the fluid pressure, and for separating the two. There is. In the present specification, the former is referred to as a positively actuated brake device, and the latter is referred to as a negatively actuated brake device.

[0004]

In the above fluid pressure brake device, the fluid chamber is sealed by a sealing means such as an O-ring or an oil seal in order to prevent leakage of the working fluid from the fluid chamber. In this case, the sealing means is arranged between the braking member and the casing which are displaced relative to each other and is frequently exposed to sliding friction. It is desirable to process the contact surface. Alternatively, it is also conceivable to use non-contact sealing means. However, all of these solutions complicate the manufacturing process of the brake device,
There is a problem of increasing manufacturing cost. An object of the present invention is to provide a fluid pressure brake device in which a friction surface is displaced in direct relation to a change in volume of a fluid chamber, in which a means for preventing leakage of a working fluid from the fluid chamber can be easily and inexpensively provided. To provide a pressure brake device.

[0005]

In order to solve the above problems, the present invention provides a movable braking member having a friction surface capable of engaging with a target surface, and a filling member formed adjacent to the braking member. A fluid chamber whose volume is changed by adjusting the pressure of the working fluid, the friction surface of the braking member is displaced in direct relation to the volume change of the fluid chamber, and the fluid pressure brake device is arranged in the fluid chamber and filled. There is provided a fluid pressure brake device comprising a flexible container that expands with an increase in pressure of the working fluid and thereby directly presses a braking member to displace a friction surface.

[0006]

The flexible container arranged in the fluid chamber is easily expanded and contracted by adjusting the pressure of the working fluid to be filled.
Due to the expansion of the container as the pressure of the working fluid increases, the wall of the container presses against the wall of the adjacent braking member, which displaces the friction surface. Since the working fluid is filled in the container, the working fluid is surely prevented from leaking from the fluid chamber.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on its preferred embodiments with reference to the accompanying drawings. In each drawing,
The same or similar components are designated by common reference numerals. FIG. 1 shows a hydraulic brake device 1 according to a first embodiment of the present invention.
Indicates 0. The fluid pressure brake device 10 includes a casing 14 arranged around a rotating shaft 12 that is an object to be braked, and a braking member 16 arranged inside the casing 14 so as to be axially displaceable so as to surround the rotating shaft 12. Prepare Casing 1
4 rotatably supports the rotary shaft 12 via bearing means 18 (for example, a tapered roller bearing). The braking member 16 is an annular element having a central opening 16a through which the rotary shaft 12 is inserted through a gap, and by the action of the rotation stopping means 20, while maintaining the concentric arrangement with the rotary shaft 12 in the casing 14. It is movably supported only in the axial direction. A friction surface 22 that extends radially is formed on one end surface of the braking member 16 in the axial direction. The other axial end surface 24 of the braking member 16 and the casing 14
An annular fluid chamber 28 surrounding the rotary shaft 12 is formed between the inner surface 26 and the inner surface 26. The fluid chamber 28 is the casing 1
4 is communicated with the surrounding environment through a hole 30 formed through. In this embodiment, the rotary shaft 12 is provided with a radially extending flange portion 32, and one axial end surface of the flange portion 32 facing the friction surface 22 of the braking member 16 forms a contact surface 34 that is a braking target surface. To do.

The friction surface 22 of the braking member 16 is
The axial displacement of 6 engages with the contact surface 34 of the flange portion 32 of the rotary shaft 12, and the rotation of the rotary shaft 12 is hindered by the friction between the two surfaces. Such action of the friction surface 22 is generated by urging the braking member 16 in the axial direction with a predetermined force and pressing the friction surface 22 against the contact surface 34 of the flange portion 32.
The fluid pressure brake device 10 shown in FIG. 1 is a positive-acting brake device.
Is provided by a flexible container 36 that expands within the fluid chamber 28 as the pressure of the working fluid being filled increases.

The container 36, as shown in FIGS.
A bag-shaped member having a port 38 arranged in the hole 30 of the casing 14, and is arranged in a given contracted state preferably over substantially the entire circumference of the annular fluid chamber 28. The working fluid is supplied to the container 36 from an external supply source 40 through a port 38 under a controllable predetermined pressure. The pressure exerted by the working fluid on the wall of the container 36 causes the container 36 to expand in the fluid chamber 28, and the wall of the container 36 presses the other axial end surface 24 of the braking member 16 to attach the braking member 16 in the axial direction. Energize. As a result, the friction surface 22 of the braking member 16 is pressed against the contact surface 34 of the flange portion 32 of the rotary shaft 12. In this case, the magnitude of the force pressing the braking member 16 is given by the product of the contact area between the wall of the container 36 and the other axial end surface 24 of the braking member 16 and the pressure of the working fluid.

Preferably, the hydraulic brake system 10 includes means for biasing the braking member 16 to pull the friction surface 22 away from the abutment surface 34 of the flange portion 32. The opposing biasing means is, for example, a return spring 42. Return spring 42
Is preferably a compression coil spring, for example, around a bolt 46 that is fixed to the casing 14 by loosely penetrating a hole 44 provided in the vicinity of the central opening 16a of the braking member 16,
It is arranged between the head 48 of the bolt 46 and the braking member 16. Therefore, in the fluid pressure brake device 10, the braking member 16 is arranged in the operating position of FIG. 1 against the bias of the return spring 42 due to the increase of the fluid pressure in the container 36 when the brake device 10 is activated. When not operated, the return spring 42 urges it to the non-acting position (that is, the position where the friction surface 22 is separated from the contact surface 34 of the flange portion 32).

As shown in FIGS. 1 and 3, the detent means 20 is at least 2 rotatably arranged in a groove 50 formed in the outer peripheral surface 16b of the braking member 16 and extending in the axial direction.
It may consist of two steel balls 52 and a push plate 58 movably arranged in a bore 54 provided at a desired position of the casing 14 and having a similar groove 56 engageable with the steel balls 52. When the push plate 58 is fixed in the bore 54 under a predetermined pressure, the steel ball 52 locks the rotary motion while allowing the axial movement of the braking member 16. In order to allow the axial movement of the braking member 16 under precise alignment, a plurality (more preferably three) of the detent means 20 are arranged in the circumferential direction of the casing 14 as shown in FIG. Is desirable. In addition,
As described above, when the bolt 46 that supports the return spring 42 is used, the bolt 46 can also serve as the rotation stopping means 20.

FIG. 4 shows a hydraulic brake system 60 according to a second embodiment of the present invention. The hydraulic brake device 60 is a negative actuated brake device, and thus, contrary to the hydraulic brake device 10 of FIG. 1, an increase in fluid pressure renders the hydraulic brake device 60 inactive. Other configurations are similar to those of the fluid pressure brake device 10 of FIG. 1, and similar components are designated by the same reference numerals as those in FIG. 1 and their description is omitted.

The fluid pressure brake device 60 includes a casing 1.
A braking member 62 is disposed inside the shaft 4 so as to surround the rotary shaft 12 and be displaceable in the axial direction. The braking member 62 is an annular element having a central opening 62a through which the rotary shaft 12 is inserted through a gap, and by the action of the rotation stopping means 20, while maintaining the concentric arrangement with the rotary shaft 12 in the casing 14. It is movably supported only in the axial direction. A radially extending friction surface 64 is formed on one axial end surface of the braking member 62 adjacent to the central opening 62a. Friction surface 64 of braking member 62
The other axial end surface 66 adjacent to the outer peripheral surface 62b on the same side as
And the inner surface 26 of the casing 14 between the rotating shaft 12
An annular fluid chamber 28 is formed surrounding the.

The friction surface 64 of the braking member 62 is the same as the braking member 6
The axial displacement of 2 engages with the contact surface 34 of the flange portion 32 of the rotary shaft 12, and the rotation of the rotary shaft 12 is hindered by the friction between the two surfaces. In the hydraulic brake device 60, the friction surface 64
A force that presses against the contact surface 34 is applied by the mechanical biasing means 68. The mechanical urging means 68 is preferably a disc spring, for example, a bolt 72 fixed to the casing 14 through a hole 70 provided between the friction surface 64 of the braking member 62 and the other axial end surface 66. Around the bolt 72
Is disposed between the head 74 and the braking member 62.

Similar to the hydraulic brake system 10 of FIG. 1,
A container 36 made of a flexible material is disposed in the fluid chamber 28, and a working fluid is supplied from an external supply source 40 under a predetermined pressure. The pressure exerted by the working fluid on the wall of the container 36 causes the container 36 to expand in the fluid chamber 28, and the wall of the container 36 presses the other axial end surface 66 of the braking member 62 to cause the braking member 6 to move.
2 is urged in the axial direction. In the fluid pressure brake device 60,
The pressing force of the container 36 acts on the braking member 62 against the urging of the mechanical urging means 68, so that the friction surface 64 is moved to the flange portion 3.
The second contact surface 34 is pulled away. Therefore, the braking member 62
Is a mechanical biasing means 68 when the brake device 60 is activated.
Is placed in the operating position (that is, the position where the friction surface 64 comes into contact with the contact surface 34 of the flange portion 32) by the urging of the brake device 60. It is placed in the inoperative position (FIG. 4) against the bias of 68.

FIG. 5 shows a hydraulic brake device 76 according to a third embodiment of the present invention. The fluid pressure brake device 76 is
A braking member 78 is disposed inside the casing 14 so as to surround the rotary shaft 12 and be displaceable in the axial direction. Braking member 7
Reference numeral 8 denotes an annular element having a central opening 78a, which is axially slidably coupled to the rotary shaft 12 by, for example, a spline coupling 80 at the central opening 78a and rotates together with the rotary shaft 12. The braking member 78 is provided with an annular recess 82 that is recessed from the outer peripheral surface in the radial direction, and a friction surface 84 that extends radially is formed on one axial end surface that forms the recess 82. A flange portion 86 that projects into the recess 82 of the braking member 78 is provided on the inner surface of the casing 14, and one axial end surface of the flange portion 86 that faces the friction surface 84 of the braking member 78 forms a contact surface 88. To do. An annular fluid chamber 28 that surrounds the rotary shaft 12 is formed between the axially other end surface 90 of the braking member 78 facing the friction surface 84 and the casing 14 and the flange portion 86 in the recess 82. The fluid chamber 28 communicates with the surrounding environment through a hole 30 formed through the casing 14.

The friction surface 84 of the braking member 78 is the same as the braking member 7
Flange portion 86 of casing 14 due to the axial displacement of 8
Engaging the contact surface 88 of the rotating shaft 12 by friction between the two surfaces.
Hinder the rotation of. The hydraulic brake device 76 of FIG. 5 is a positive-acting brake device in which the force pressing the friction surface 84 against the abutment surface 88 expands in the fluid chamber 28 as the working fluid pressure increases. It is provided by the container 36.

The fluid pressure brake device 10 shown in FIGS. 1 and 4,
Similar to 60, the container 36 placed in the fluid chamber 28 includes
The working fluid is supplied from an external supply source 40 under a predetermined pressure. The pressure exerted by the working fluid on the wall of the container 36 causes
The container 36 expands in the fluid chamber 28, and the wall of the container 36 presses the other axial end surface 90 of the braking member 78 to urge the braking member 78 in the axial direction. As a result, the friction surface 84 of the braking member 78 is pressed against the contact surface 88 of the flange portion 86 of the casing 14.

The fluid pressure brake device 76 includes a return spring 92 that biases the braking member 78 to separate the friction surface 84 from the contact surface 88 of the flange portion 86. Return spring 92
Is preferably a compression coil spring, and the bearing means 94
It is arranged between the wall of the casing 14 and the braking member 78 via (for example, a thrust ball bearing). Therefore, in the fluid pressure brake device 76, the braking member 78 is arranged in the operating position of FIG. 5 against the bias of the return spring 92 due to the increase of the fluid pressure in the container 36 when the brake device 76 is operated, and the braking device 78 is disposed. When not operated, the return spring 92 urges it to the non-acting position (that is, the position where the friction surface 84 is separated from the contact surface 88 of the flange portion 86).

In the fluid pressure brake device 76, since the braking member 78 rotates together with the rotary shaft 12, the braking member 7
It is desirable to install another bearing means 96 (for example, a thrust ball bearing) between the other axial end surface 90 of 8 and the container 36 as shown. In this case, the container 36 that expands in the fluid chamber 28 presses the other axial end surface 90 of the braking member 78 via the bearing means 96. Further, when the brake device 76 is not operated, the fluid pressure in the container 36 is appropriately controlled so that the braking member 78 and the casing 14 do not come into contact with each other, and the axial displacement of the braking member 78 is adjusted by the friction surface 84.
It is desirable to limit the distance between the contact surface 88 and the contact surface 88 to the minimum range required.

Although the preferred embodiments of the present invention have been described above, the present invention can be implemented in the following modes, for example. The fluid pressure brake device according to the present invention preferably uses air as the working fluid supplied to the container 36. In this case, a compressor device supplying compressed air under controllable pressure is used as the source 40. When the working fluid is a liquid, it is necessary to select the material of the container in consideration of the effects of chemical changes on the container.

The container 36 can be formed from any flexible material that has the desired resistance to damage.
Suitable materials for the container 36 include polymeric materials such as synthetic rubber and plastics (preferably fiber reinforced vinyl). The size and shape of the container 36 can be arbitrarily set according to the size and shape of the fluid chamber 28 and the hole 30, but the wall thickness of the container 36 can be easily deformed by the pressure change of the working fluid, but is easily It is desirable that the thickness is in the range of 1 mm to 1 cm depending on the material characteristics so as not to be damaged. Container 3
The shape of 6 may be an elongated bag shape as shown in FIG. 6 in addition to the annular endless tube shape as shown in FIG. When the container 36 is formed of an endless tube, the hydraulic brake device shown in each drawing is disassembled by removing the required bolts, thereby placing the container 36 in the exposed fluid chamber 28. When the container 36 is formed of an elongated bag, it can be placed in the fluid chamber 28 by inserting the container 36 through the hole 30 of the casing 14 of the hydraulic brake device which has been assembled. The casing 14
One hole 30 and one mouth 38 of the container 36 may be provided at arbitrary positions. A well-known mouthpiece can be attached to the mouth 38 of the container 36 if desired.

The braking member of the hydraulic brake system preferably comprises a suitable friction material. In this case, the friction surface of the braking member or the contact surface which is the target surface may be formed by a separate pad made of a friction material. Further, the friction surface and the contact surface may be arranged at a desired angle with respect to the radial arrangement shown in each drawing. Further, the present invention can be applied not only to the structure in which the friction surface of the braking member is urged in the axial direction but also to the brake device in which the friction surface is urged in the radial direction.

[0024]

As is apparent from the above description, according to the present invention, a flexible container is arranged in the fluid chamber adjacent to the braking member, and the braking member is adjusted by adjusting the pressure of the working fluid filled in the container. Since the friction surface is displaced, the leakage of the working fluid from the fluid chamber can be reliably prevented without sealing the fluid chamber with the sealing means. The container can be made of any flexible material with the desired durability and can be easily placed in the fluid chamber during the assembly process of the hydraulic brake system. Therefore, according to the present invention, there is provided an inexpensive and highly reliable fluid pressure brake device that reliably prevents the leakage of the working fluid from the fluid chamber.

[Brief description of drawings]

FIG. 1 is a sectional view of a fluid pressure brake device according to a first embodiment of the present invention.

2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view of a fluid pressure brake device according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a fluid pressure brake device according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a modified example of the flexible container according to the present invention, corresponding to FIG.

[Explanation of symbols]

 10, 60, 76 ... Fluid pressure brake device 12 ... Rotating shaft 14 ... Casing 16, 62, 78 ... Braking member 18, 94, 96 ... Bearing means 20 ... Rotation stop means 22, 64, 84 ... Friction surface 28 ... Fluid chamber 30 ... Hole 32, 86 ... Flange part 34, 88 ... Contact surface 36 ... Container 38 ... Port 40 ... Supply source 42, 92 ... Return spring 46, 72 ... Bolt 68 ... Mechanical biasing means

Claims (1)

[Claims] 1. A movable braking member having a friction surface engageable with a target surface, and a fluid chamber formed adjacent to the braking member, the volume of which changes by adjusting the pressure of a working fluid filled therein. A fluid pressure brake device in which the friction surface of the braking member is displaced in direct relation to a change in volume of the fluid chamber, wherein the working fluid is disposed in the fluid chamber and expands with an increase in pressure of a working fluid filled therein. The fluid pressure brake device further comprises a flexible container for directly pressing the braking member to displace the friction surface.