JPH0124439Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a braking device that prevents relative movement between a shaft and a bearing body that are relatively movable in the axial direction.

Stops the axis moving in the axial direction at a predetermined position,
In various technical fields, it is often necessary to stop an object moving along an axis at a predetermined position on the axis. One of the typical examples is an air cylinder. Since air cylinders use compressible air as the working fluid, the piston rod does not stop immediately even if the air supply is cut off, making it impossible to stop the piston rod at an accurate position. Therefore, when it is necessary to stop the piston at an accurate position, conventionally, a fixed stopper is generally provided, and the piston rod or a fixed member is brought into contact with the stopper to stop the piston rod.

However, in this case, it is difficult to arbitrarily change the stopping position, which is why a braking device is needed. In addition, braking devices are required in various fields, such as when preventing relative movement between the guide rod and the moving table in order to make the moving table guided by the guide rod in the same state as if it were fixed to the frame at a desired position. It becomes.

In view of these needs, the present invention has been devised for the purpose of providing an axial braking device that has a simple structure, can be constructed in a small size, and can provide sufficient response speed and braking force.

To achieve this purpose, the axial braking device according to the present invention includes (a) a cylinder that is provided immovably relative to the bearing body and allows the shaft to pass through, and (b) an annular cylinder with an outer circumferential surface. (c) a piston whose inner circumferential surface is hermetically and slidably fitted to the cylinder;
It has a cylindrical shape, has at least one slit formed in the axial direction, is contractible in the radial direction, is fitted onto the shaft, and is fixed to the cylinder so that it cannot move relative to the cylinder in the axial direction. and (d) a disc spring-like shape as a whole, which is fitted onto the outer circumferential surface of the brake shoe and compressed in the axial direction by the piston, thereby contracting its small diameter and tightening the brake shoe. , a tightening member that presses the inner circumferential surface of the brake shoe against the outer circumferential surface of the shaft, and (e) piston driving means that moves the piston in the axial direction based on selective supply of pressurized fluid to the cylinder. Constructed to include.

Note that the term "bearing body" here refers not only to a literal bearing device that supports a shaft so that it can slide in the axial direction, but also to a broader term that includes a part that is fitted with the shaft of an object that moves along the shaft. Use as.

Furthermore, a cylinder that is provided immovably relative to a bearing body is not only a cylindrical body, but also a cylinder that is independently constructed with a cover that closes both ends, and is used by being attached to a separately provided bearing body. Furthermore, the term also refers to a cylinder in which one or both of the covers also serve as a bearing body.

In a braking device configured in this way, the brake shoe can be pressed against the shaft by a compact and simple-structured tightening member, so the overall structure is simple, and a small and inexpensive axial braking device can be used. This will be obtained. Moreover, since the tightening member can tighten the brake shoe in response to an extremely small operating stroke of the piston, a highly responsive braking device can be obtained, and the volume of the pressure chamber in the cylinder can be reduced. Even when the working fluid is gas, the delay in actuation due to compressibility is reduced and a braking device with sufficient response speed can be obtained. In addition, the disc spring-shaped tightening member itself has directionality, and although it can prevent movement of the shaft in one direction when acting directly on the shaft, it does not have the ability to prevent movement in the opposite direction. However, in the braking device according to the present invention, since the brake shoe cannot move relative to the cylinder in the axial direction, one set of the tightening member and the brake shoe can move the shaft in both forward and reverse directions. A braking device is obtained which can prevent movement.

Hereinafter, some embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows an example of a braking device for stopping the piston rod of an air cylinder at a desired position.A cylinder 2 forming the main body of this braking device is removably attached to a rod cover 4 of the air cylinder. The cylinder 2 has a square outer shape and a circular bottom hole in the center, and a first tube 6 is disposed such that the open sides of the bottom holes are opposed to each other.
and a second tube 8, and an annular first piston 10 and a second piston 12 are fitted in the respective tubes 6, 8 in an airtight and slidable manner. A port member 18 having a first port 14 and a second port 16 is disposed between the open ends of the tubes 6, 8. 1st port 14
is a through hole 20 formed in the center of the port member 18
are connected to rear pressure chambers 22 and 24 formed on the rear side of the pistons 10 and 12 through the pistons 10 and 12.

On the other hand, the second port 16 has a communication path 2 formed through the port member 18 and the tubes 6 and 8.
6, the pistons 10 and 12 are connected to front pressure chambers 28 and 30 formed in front of them. A rod cover 32 is provided on the bottom side of the second tube 8. The first tube 6, the port member 18, the second tube 8, and the rod cover 32 are respectively positioned in the radial direction by fitting into the fitting hole and the fitting protrusion, and are inserted through these. It is fixed to the rod cover 4 of the air cylinder by provided bolts 34 and nuts 36, forming an integral cylinder 2. In this example, the airtightness between the above-mentioned members is maintained by bringing the flatly ground end surfaces into close contact with each other, but sealing members such as gaskets and O-rings may also be used. Of course it is possible. Air cylinder piston rod 3
8 extends through the center of the cylinder 2 and both pistons 10 and 12. Airtightness between the piston rod 38 and the cylinder 2 is achieved by sealing members 40 and 42 provided on the rod cover 4 of the air cylinder and the cylinder 2. The rod cover 32 is held by seal members 44 and 46 provided on the rod cover 32.

A brake shoe 50 is disposed in an annular gap formed between the inner peripheral surface of the through hole 48 formed at the center of the bottom of the second tube 8 and the outer peripheral surface of the piston rod 38. brake show 50
As is clear from FIG. 2, this is a cylindrical member with one axial slit 52 formed therein so that the diameter can be reduced by elastic deformation.
It is in close contact with the inner circumferential surface of the through hole 48 of the tube 8, so that a minute clearance is formed between the inner circumferential surface and the outer circumferential surface of the piston rod 38. The brake shoe 50 has an annular projection 5 on the outer peripheral surface of one end.
4, this protrusion 54 is fitted into a counterbore hole 56 formed at one end of the through hole 48, and the bottom surface of the counterbore hole 56 and the rod cover 32
It is attached to the cylinder 2 so as to be immovable in the axial direction by being sandwiched from both sides by the distal end surface of the fitting protrusion 58 .

The end of the brake shoe 50 opposite to the side on which the protrusion 54 is formed is connected to the front pressure chamber 30 by a certain length.
A tightening member 60 in the form of a disc spring is fitted onto the outer peripheral surface of this portion. As shown in FIG. 3, in the tightening member 60, a plurality of notches 62 are formed radially at equal angular intervals from the small diameter side, and radial notches 64 are formed from the large diameter side as well. It is formed to be located in the middle. The large diameter side of this tightening member 60 is fitted into a counterbore hole 66 formed in the front end surface of the second piston 12. As shown in FIG. 4, a shallow annular groove 69 is formed in the inner peripheral surface of the counterbore hole 66 in a portion adjacent to the counterbore bottom surface 68.
The circumferential edge of the tightening member 60 is fitted into the second piston 9 so that it does not move relative to the second piston 12 in the axial direction.

The brake shoe 50 and the tightening member 60 constitute a second braking section 70 together with the second piston 12 and the second tube 8, but the first piston 1
A brake shoe 72 and a tightening member 74 are similarly arranged on the 0 side, and together with the first tube 6 constitute a first braking section 76.

A compression coil spring 78 is disposed between the first piston 10 and the second piston 12 with a predetermined preload, and always urges both pistons 10 and 12 in the forward direction. the result,
On the second piston 12 side, the tightening member 60 is compressed in the axial direction between the second tube 8 and the second piston 12. The tightening member 60 originally has a property that when compressed in the axial direction, the large diameter expands and the small diameter contracts. Since it is regulated by the bottom surface of the annular groove 69 formed on the circumferential surface, more precisely on the inner circumferential surface, the inner diameter can be contracted particularly effectively. Therefore, due to this small diameter contraction, the brake shoe 50
is contracted and pressed against the outer peripheral surface of the piston rod 38 to prevent relative movement of the piston rod 38 with respect to the brake shoe 50. Moreover,
As described above, this brake shoe 50 is attached so as not to be able to move in the axial direction with respect to the cylinder 2, so that the piston rod 38 is ultimately prevented from moving relative to the cylinder 2 in the axial direction.
On the other hand, the tightening member 74 also
is axially compressed, tightening the brake shoe 72 and preventing axial movement of the piston rod 38. That is, the braking device of this embodiment is a constantly braking type braking device.

The braking device configured as described above is used by being connected to an air source 82 via an electromagnetic directional control valve 80. As the air source 82, an air source for operating an air cylinder to which this braking device is attached can be used, and in this case, a braking force proportional to the operating force of the piston rod 38 will be obtained. . This is because both the actuation force and the braking force are proportional to the pressure of the air supplied from the air source 82.

The switching valve 80 normally communicates the rear pressure chambers 22 and 24 with the air source 82 and the front pressure chambers 28 and 30.
is in a state where it is released into the atmosphere. Therefore, both the first braking section 76 and the second braking section 70 are kept in a braking state by the elastic force of the spring 78 and the air pressure acting on the rear pressure chambers 22 and 24, and the piston rod 38 is kept sufficiently large. It is held still by braking force. However, if a very large braking force is not required, the supply of air to the rear pressure chambers 22 and 24 can be omitted. Further, in this case, there is an advantage that the switching valve can be a 3-port 2-position switching valve.

When it becomes necessary to move the piston rod 38, the front pressure chambers 28 and 30 are brought into communication with the air source 82 by switching the switching valve 80, and the rear pressure chambers 22 and 24 are opened to the atmosphere.

As a result, the pistons 10 and 12 are retracted against the elastic force of the spring 78, the axial compression of the clamping members 74 and 60 is released, and the small diameters of both clamping members are expanded. Therefore, the brake shoes 72 and 50 are also enlarged and the piston rod 38
is allowed to move in the axial direction. The operating strokes of the pistons 10 and 12 required for this purpose are extremely small, and therefore the front compression chamber 2
8 and 30 can be made small in volume, and the delay in operation of the braking device due to the compressibility of air can be reduced.

When the piston rod 38 moves to a predetermined position and needs to be stopped again, the switching valve 8
Power supply to solenoid 0 is cut off, switching valve 8
0 is again switched to the state shown in FIG. 1, the front pressure chambers 28 and 30 are released to the atmosphere, air is supplied to the rear pressure chambers 22 and 24, and the pistons 10 and 12 are moved forward.
The brake shoes 72 and 50 are contracted by the tightening members 74 and 60, and the first brake part 76
Both the second braking section 70 return to the braking state and stop the piston rod 38. This braking device also has excellent responsiveness in this case.

As is clear from the above description, in this embodiment, pressure fluid is selectively supplied to the cylinder 2 by a pressure fluid supply device consisting of an air source 82, a switching valve 80, etc., and a compression coil spring. A piston driving means for moving the piston in the axial direction is configured.

FIG. 5 shows a braking device according to another embodiment of the present invention. This braking device is for preventing the axial movement of the piston rod 38 of the air cylinder as in the above embodiment, and a compression coil spring 78 is provided between the first piston 10 and the second piston 12. The front pressure chamber 28
The main difference from the previous embodiment is that a second port 16 communicating with the second tube 8 and 30 is formed in the second tube 8, and since the other components are almost the same, corresponding elements are designated by the same reference numerals. The correspondence relationship between the two is shown with reference to FIG. 2, and a detailed explanation will be omitted.

In this braking device, the clamping members 74 and 60
is normally not axially compressed, so when brake shoes 72 and 50 are in an expanded state,
The piston rod 38 is in a movable state. In other words, this braking device is a constantly release type braking device. Additionally, in this braking device, the pistons 10 and 12 are connected to the front pressure chambers 28 and 30.
The first piston 10 and the first
between the tube 6 and the second piston 12 and the second
It is also possible to interpose an elastic member for piston return between the tube 8 and the axial direction of the tightening members 74 and 60 without supplying air to the front pressure chambers 28 and 30. The advantage is that the compression is completely released, the clamping force of the brake shoes 72 and 50 is completely eliminated, and the axial movement of the piston rod 38 is easy.

FIG. 6 shows another embodiment of the present invention. In the figure, 4 is the rod cover of the air cylinder, and 38
is the piston rod of the air cylinder. The cylinder 100 of this embodiment is composed of a tube 102, a rod cover 104, a seal plate 106, and a brake shoe holding member 108.

The seal plate 106 is a disc member with a through hole in the center, and O-rings 110 and 112 are attached to the outer and inner circumferential surfaces to maintain airtightness between the tube 102 and the piston rod 38. Therefore, there is no need to grind the mutually abutting end surfaces of the rod cover 4 and the tube 102 as in the previous embodiment, and the braking device of this embodiment has the advantage that it can be easily attached to a normal air cylinder. Further, the shoe holding member 108 works together with the seal plate 106 to hold the brake shoe 11.
4 so that it cannot move in the axial direction and can be reduced in diameter, and is held between the C-shaped retaining ring 116 attached to the tube 102 and the rod cover 4 together with the seal plate 106. movement is prevented. 118 is a tightening member;
Reference numeral 120 denotes a piston, but since these are similar to those in the previous embodiment, detailed explanation will be omitted.

Also in the braking device of this embodiment, when air is supplied from the port 122 to the rear pressure chamber 124, the piston 1
20 moves forward and compresses the clamping member 118 in the axial direction, and as a result, the brake shoe 114 is pressed against the outer peripheral surface of the piston rod 38 to prevent its axial movement, and the front pressure chamber 126 is transferred from a port (not shown) to the front pressure chamber 126. When air is supplied, the piston 120 is retracted to allow axial movement of the piston rod 38.

Although typical embodiments of the present invention have been described above, the present invention may be implemented in other forms as well.

For example, a normal disc spring can be used as the clamping member, or a clamping member 86 in which a radial slit 84 is formed in a part of a regular disc spring as shown in FIG. 7 can also be used. It is possible. Furthermore, as shown in FIG. 8, it is also possible to use a tightening member 90 in which a plurality of notches 88 are formed radially from the small diameter side of the disc spring at equal angular intervals; in this case, the large diameter side is connected in an annular manner. Because of this, when the tightening member 90 is compressed in the axial direction, there is little expansion of the large diameter and the small diameter effectively contracts, so it is necessary to form a counterbore hole in the piston to restrict the expansion of the large diameter. There is an advantage that it disappears. The tightening member can have various other shapes, and it is also possible to use a plurality of tightening members stacked one on top of the other.

Furthermore, the brake shoe is also as shown in Figure 9.
A brake shoe 96 has a structure in which a lining piece 94 divided into a plurality of pieces by a plurality of axially parallel slits 93 is held in an outer cylinder 92 that is almost the same as the brake shoe 50 in the above embodiment. It is also possible to use In this case, the outer cylinder 92 is made of a material with excellent strength and elasticity, and the lining piece 94 is made of a material such as synthetic resin, gunmetal, asbestos, etc., which has good conformability and does not cause damage to the outer peripheral surface of the piston rod 38. This has the advantage of making it possible. Furthermore, the brake shoe does not necessarily have the property of expanding its diameter due to its own elasticity; it is also possible to use a brake shoe that is divided into multiple pieces by slits in the axial direction. Any material may be used as long as it has a substantially cylindrical shape in the assembled state and can be reduced in diameter.

Although the annular protrusion 54 in the embodiment described above is suitable as a means for preventing relative movement of the brake shoe in the axial direction with respect to the cylinder, it may be screwed onto the cylinder and the outer peripheral surface of the brake shoe may be disposed at the tip thereof. It is also possible to use a set screw that engages with an engagement hole formed in the.

Furthermore, if a larger braking force than in each of the above embodiments is required, the air supplied to the air cylinder is not directly supplied to the cylinder 2, but is increased in pressure by a pressure intensifier and then transferred to the cylinder. It is also possible to supply it to 2. Further, the pressure fluid is not limited to gas such as air, but liquid such as oil can also be used. Furthermore, it is also possible to configure a switching valve or the like that controls the supply of pressure fluid to the braking device integrally with the cylinder.

In addition, it goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims for utility model registration.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing a constant braking type braking device which is an embodiment of the present invention. Figure 2 is the first
FIG. 3 is a front view of a brake shoe used in the braking device shown in the figure, and FIG. 3 is a front view of a tightening member as well. FIG. 4 is an enlarged sectional view showing the vicinity of the tightening member in FIG. 1. FIGS. 5 and 6 are front views, each showing a partially sectional view of a normally-release type braking device according to another embodiment of the present invention. 7th
8 and 8 are front views showing different clamping members used in the braking device according to the present invention. FIG. 9 is a front view showing a part of the brake shoe used in the braking device according to the present invention in cross section. 2,100: cylinder, 10: first piston,
12: Second piston, 38: Piston rod, 5
0, 72, 96, 114: Brake shoe, 5
2, 84, 88: slit, 54: protrusion, 56,
66: Counterbore hole, 58: Fitting protrusion, 60, 74,
86, 90, 118: Tightening member, 62, 64: Notch, 68: Bottom of counterbore hole, 69: Annular groove, 70:
Second braking section, 76: First braking section, 78: Compression coil spring, 80: Electromagnetic directional control valve, 82: Air source, 92: Outer cylinder, 94: Lining piece, 10
6: seal plate, 108: shoe holding member,
120: Piston.

Claims (1)

[Claims for Utility Model Registration] (1) A braking device that prevents relative movement between a shaft that is relatively movable in the axial direction and a bearing body, which is provided so as not to be movable relative to the bearing body, and that is provided so as to prevent the shaft from penetrating the shaft. a cylinder having an annular shape and having an outer peripheral surface fitted to the cylinder and an inner peripheral surface fitting to the shaft in an airtight and slidable manner; a piston having a cylindrical shape and formed in the axial direction; a brake shoe having at least one slit and retractable in the radial direction, fitted onto the shaft and fixed to the cylinder so as not to be relatively movable in the axial direction; is fitted onto the outer circumferential surface of the brake shoe and compressed in the axial direction by the piston, thereby contracting its small diameter and tightening the brake shoe, thereby tightening the inner circumferential surface of the brake shoe. An axial braking device comprising: a tightening member that presses against an outer circumferential surface of a shaft; and a piston drive means that moves the piston in the axial direction based on selective supply of pressure fluid to the cylinder. (2) The piston driving device supplies a spring that urges the piston in a direction in which the tightening member is compressed, and a pressure fluid to the cylinder to move the piston against the elastic force of the spring. 2. The axial braking device according to claim 1, which is always in a braking state and includes a pressure fluid supply device that provides a pressure fluid.