JPH044935Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a brake actuator that is mainly used in brake equipment for railway vehicles and generates braking force using pneumatic pressure, oil pressure, spring force, electric motor, etc. , especially those having an automatic clearance adjustment mechanism and a manual loosening mechanism.

<Prior Art> A conventional brake actuator having an automatic clearance adjustment mechanism is disclosed in Japanese Patent Publication No. 15960/1983. The automatic gap adjustment mechanism automatically reduces the gap between the wheel tread and the brake shoe to the set value when the gap between the wheel tread and the brake shoe increases due to wear of the brake shoe or wheels of the brake system. It was designed to do so. The outline of this automatic gap adjustment mechanism will be explained using FIG. 4.

In FIG. 4, when pressurized air is supplied to the cylinder chamber 2 formed in the cylinder body 1 as the main body, the air pressure causes the piston 3 to return and move to the left against the spring 4, and this moving force is transmitted in order from the piston 3 to a cylindrical rod 5 integrated with the piston 3, a first nut 7 that meshes with a protrusion 6 in the rod 5, and a push rod 8 that is screwed into the inside of the first nut 7. Move it to the left. The tip of the push rod 8 is connected to a link or a brake shoe suspension, and although it does not rotate, it can move back and forth, and forward movement to the left causes the brake device to perform a braking action.

At this time, if the gap between the brake shoe and the wheel tread is the set value, the protrusion 10 of the cylindrical control member 9 slidably provided in the cylindrical rod 5 comes into contact with the first stopper 11. In this state, the piston 3 stops. The control member 9 and the second nut 12 remain in mesh. Then, when the cylinder chamber 2 is evacuated, the piston 3 retreats to the right by the action of the return spring 4. At this time, the relative positions of the cylindrical rod 5 and the push rod 8 do not change, and they move as one.

If the gap exceeds the set value due to wear of the brake shoes or wheels, the control member 9
The protrusion 10 contacts the first stopper 11, and the control member 9 is stopped at that position, but the piston 3 and the rod 5 move further leftward than the predetermined stroke L by a stroke corresponding to the amount of wear. At this time, the force transmitted to the push rod 8 via the protrusion 6 of the rod 5 and the first nut 7 is transmitted to the second nut 12 and moves the second nut 12 to the left against the second spring 13. As a result, the second nut 12 is disengaged from the control member 9 and rotates along the male threaded portion on the outer periphery of the push rod 8 that is screwed together by the acting force (axial thrust) of the second spring 13. The threaded engagement position with the push rod 8 moves to the right, and then it meshes with the control member 9 and stops. Therefore, the push rod 8 moves forward together with the rod 5 more than before wear, and this extra amount of movement corresponds to the amount of wear.

Next, when the cylinder chamber 2 is evacuated, the piston 3 is returned to its original position by the action of the return spring 4. At this time,
Together with the piston 3, the rod 5, first nut 7, push rod 8, second nut 12, and control member 9 retreat to the right. If this retreat amount exceeds the predetermined stroke L,
The projection 10 of the control member 9 comes into contact with the second stopper 14, and the control member 9, second nut 12, and push rod 8 are stopped at that position, but the piston 3 and rod 5 are further retreated to the right. This causes the first spring 1
5 is compressed, the first nut 7 and the protrusion 6 are disengaged, and the first nut 7 rotates along the male threaded portion of the push rod 8 by the acting force (axial thrust) of the first spring 15, and the push rod 8 The screwing position with the protrusion 6 moves to the right.
The teeth meet and stop. This completes the automatic adjustment of the gap. Compared to the state before the automatic adjustment, the push rod 8 has moved to the left relative to other parts by the gap adjustment amount.

A conventional brake actuator with a manual release mechanism is described in US Pat. No. 3,498,188. The outline will be explained using FIG. 5.

In this case, a ball clutch 22 as a manual release mechanism is provided between the piston 19 of the spring brake cylinder 17, which is formed separately from the brake cylinder for normal brake operation, and the push rod 21. This brake cylinder 17 has a push rod 21 connected to a lever of a brake device (not shown), and when the push rod 21 moves to the left, it engages with the lever and swings the lever to apply the brake.

A normal brake operation using the air brake cylinder is performed while the push rod 21 is moving to the right as shown in the lower half of the figure. In this state, pressurized air is supplied to the cylinder chamber 17a of the spring brake cylinder 17 to move the piston 19 to the right against the spring 20 for the spring brake, and the clutch 22 connects the piston 19 and the push rod 21. It is in a state of being

The spring brake cylinder 17 is used, for example, when the brake is applied when parking, and is normally in the state shown in the lower half of the figure, but when the pressure air in the cylinder chamber 17a is exhausted, the spring 20
The force causes the right end of the push rod 21 to pull the lever to the left, applying the brake.

A clutch 22 as a manual release mechanism is provided to release the brake without using pressurized air when the spring brake cylinder 17 is braking. A groove 21a provided, several balls 24 that engage with the groove 21a, an operating member 23, a spring 2
It is composed of 5th grade. Ball 24 is piston 1
It is held in a hole 19a bored at a predetermined position in a cylindrical portion formed in 9. The lower half of the figure shows the engaged state of the clutch 22, and the upper half shows the disengaged state of the clutch 22. clutch 22
The operation member 23 is connected to the spring 25 due to the connected state.
By moving it in the axial direction against the
3a is now located outside the ball 24, resulting in a disconnected state. In this disconnected state, even if the cylinder chamber 17a is evacuated and the piston 19 moves to the left, the push rod 21 does not move to the left, so no braking force is applied by the spring brake cylinder 17.

<Problems to be Solved by the Invention> Conventionally, there has been no brake actuator that has both an automatic clearance adjustment mechanism and a manual release mechanism. now,
If a brake actuator were to incorporate a conventional automatic clearance adjustment mechanism and manual release mechanism, it would be necessary to provide a clutch between the piston and the piston rod, and an automatic clearance adjustment mechanism between the piston rod and the push rod. There is a problem that the structure becomes complicated and expensive.

Furthermore, recently, brake cylinders operated by air or springs are equipped with automatic gap adjustment mechanisms in order to save the effort of gap adjustment and to minimize the stroke of the cylinder to make it more compact. Also,
Increasingly, spring brakes are built into brake cylinders, and it is now necessary to have a release mechanism that releases the brake from the outside when the brake remains applied due to some abnormality.

An object of the present invention is to provide a means for adding a manual release mechanism to a conventional brake actuator equipped with an automatic clearance adjustment mechanism without increasing the size or cost.

<Means for Solving the Problems> The means of this invention is that in a brake actuator equipped with an automatic clearance adjustment mechanism similar to that explained using FIG. 4, the first nut and the cylindrical rod side are A first clutch that switches the meshing state between at least a connected state in which rotation of the first nut is locked in the direction in which the first nut advances along the push rod and a released state in which the lock is released is set between the first nut and the first nut. It is characterized by being installed between the rod and the rod.

<Operation> According to the above means, in the coupled state where the first clutch is engaged, automatic gap adjustment similar to the conventional automatic gap adjustment mechanism is performed. Further, in the released state in which the first clutch is in the releasing state, the first nut is rotatable, so that the first nut rotates and follows the male thread of the push rod as the rod advances and retreats. Therefore, when the rod moves forward and the brake is activated, if the first clutch is released, the push rod is moved back by the return spring on the brake device side and the brake is released even if the rod is in the forward position.

<Example> A first example will be described using FIG. 1. In FIG. 1, 30 is a cylinder body as a main body, 31
is the first piston for the air brake, 32 is the second piston for the spring brake, and 33 is the first piston 3
1 spring for return, 34 spring for spring brake,
35 is a push rod, 36 is an automatic clearance adjustment mechanism, 37 is a first clutch, and 38 is a second clutch.

The cylinder body 30 has a first piston 31 and a second piston 32 housed therein so as to be in contact with each other, and a cylinder chamber 40 is formed between them. 41 in the figure is a supply/discharge hole for pressurized air. In this embodiment, the cylinder body 30 is screwed to an extension cylinder 42 and fixed with a setscrew 43 in order to provide an automatic clearance adjustment mechanism 36 and a first clutch 37 at the left end in the figure.

The first piston 31 has a cylindrical rod 44 extending to the left in the figure, and the rod 44 is provided with an axial groove 45 in which the inner protruding end of the set screw 43 is inserted. This prevents the rod 44 from rotating relative to the cylinder body 30 within the stroke range of the first piston 31. The rod 44 is also screwed to the extension 46 and fixed with a set screw 47.

The second piston 32 has a piston rod 48 extending to the right in the figure, and this rod 48 is adapted to be engaged and released by a second clutch 38, which will be described later.

The spring 33 for returning the first piston 31 is provided between the first piston 31 and the cylinder body 30 as shown in the figure, and acts to press the first piston 31 to the right.

In the illustrated state, the spring 34 for the spring brake is connected to the second piston 32 and the cylinder body 30 which are locked by the second clutch 38 in a position retracted to the right.
It is in a compressed state because it is provided between the right end wall of the

The push rod 35 applies braking force to the brake device by being driven forward to the left in the figure, and its right end is inserted into the rod 44 of the first piston 31, and a male thread 49 is formed on the outer periphery. has been done.

The automatic gap adjustment mechanism 36 has a male thread 4 of the push rod 35.
9, the first nut 50 and the second nut 51 are screwed together.
It is composed of a first spring 52, a third spring 54, a control member 55, etc. related to the. The first nut 50 is pushed from the front side by an inner protrusion 56 of the extension 46 of the rod 44 by a first spring 52, and the other end of the first spring 52 is supported by a spring receiver 57 provided on the extension 46. has been done. A circumferential groove 58 that is open to the rear side is formed on the outer periphery of the first nut 50.
The front side surface of the groove 58 is formed into a predetermined uneven surface 59. In the figure, 60 and 61 are thrust bearings. The second nut 51 is provided closer to the first piston 31 than the first nut 50. A control member 55 is arranged on the outer periphery of the second nut 51, and the second nut 51 meshes with the front end of the control member 55 from the front side. The meshing state is such that a part of the outer periphery of the second nut 51 is inclined diagonally rearward to form a tapered surface with small bevel gear-like teeth, and a surface formed on the control member 55 side to match the tapered surface. are engaged. The control member 55 is the rod 44
The extension tube 42 of the cylinder body 30 passes through the groove 45 of the cylinder body 30.
A protrusion 62 reaching up to this point is provided by screwing the protrusion member. The protrusion 62 is connected to the extension cylinder 42.
It is movable in the axial direction within the cavity formed in the
Its movement range is regulated by stoppers 63 and 64, and its movement distance L is a predetermined stroke defined for performing a braking action. The second spring 54 has spring receivers 65 and 6 on the outer periphery of the second nut 51.
6 and a thrust bearing 67, the front end thereof faces the rear side of the control member 55,
The meshing state between the second nut 51 and the control member 55 is maintained. The first nut 50 and the rod 44 are engaged with the first ball 68 of the first clutch 37.

The first clutch 37 includes a first ball 68 , a ball holding hole 69 that holds the first ball 68 in the extension part 46 at a position outside the groove 58 of the first nut 50 so as to be displaceable in the radial direction, and a ball holding hole 69 in the extension part 46 . The first ball 68 is rotatably provided on the outer periphery and depending on its rotational position, the first ball 68 is projected into the groove 58 and the ball holding hole 6
A ball regulating member 7 that regulates the state in which the ball enters the ball.
0. It consists of an operating rod 72 having a claw 71 provided to rotate the ball regulating member 70 from the outside of the cylinder body 30. This first clutch 3
The structure of No. 7 is the same as that of the clutch in Japanese Patent Application No. 1983-71600. When the ball regulating member 70 is in a predetermined rotation state, the first ball 68 is restrained in the groove 58, and this is the meshing state between the rod 44 side and the first nut 50, and the engaged state of the first clutch 37. . As a result, the first nut 50 is connected to the rod 44.
Rotation is prevented from the side via the first ball 68. That is, the first ball 68 is engaged with the uneven surface 59 of the groove 58, as seen in FIG. 1b. Further, when the ball regulating member 70 is operated from the illustrated predetermined rotational position to another rotational position, that is, when the first clutch 37 is released, the first ball 68 moves within the ball holding hole 69 at the radius of the extension portion 46. This allows the first nut 50 to rotate outward.

The second clutch 38 is provided inside an inner cylinder 73 extending from the right end wall of the cylinder body 30 to the inside of the spring 34 for the spring brake. 2 piston 3
A ball holding hole 76 and a second ball 7 are held at a position outside the ball engaging groove 75 of the piston rod 48 in the second retracted position and can be moved in and out of the groove 75.
The pilot piston 78 is formed integrally with the cylinder 77, a pilot air chamber 79, a return spring 80, and the like.

This second clutch 38 is configured such that when pressurized air is supplied to the pilot air chamber 79 from the supply/exhaust hole 81 when the second piston 32 is in the rightward retreat position, the pilot piston 78 advances the cylinder body 77 to the state shown in the figure. The second ball 74 is restrained in the position where it is engaged with the groove 75, thereby locking the second piston 32 so that it does not move forward. That is, the second clutch 38
becomes a connected state. When the pressurized air in the pilot air chamber 79 is exhausted from this state, the pilot piston 78 moves the cylindrical body 77 backward by the return spring 80, and the second ball 74 can be displaced outward, and the second clutch 38 is released. Become.

As shown in the figure, in this brake actuator 81, when the first clutch 37 and the second clutch 38 are in the engaged state, the push rod 35 is in a position retreated to the right, and the brake is released. When pressurized air is supplied into the cylinder chamber 40 from the supply/discharge hole 41 in this state, the first piston 31 is activated by the return spring 33.
Move forward to the left against the This first piston 31
As the push rod 35 moves forward, the brake device is actuated to apply the brake. Further, when the pressurized air in the cylinder chamber 40 is exhausted, the brake is released. This is normal air brake operation.

When applying the spring brake, the second clutch 38 is released by discharging the pressure air from the pilot air chamber 79, and the second piston 32 moves to the left under the action of the spring 34, thereby pushing the first piston 31 forward. Since it is moved forward, the spring brake comes into play in the same way as above. Second piston 32
To return the clutch to the retracted position, pressurized air is supplied into the cylinder chamber 40 to retract the second piston 32, and then pressurized air is supplied into the pilot air chamber 79 to bring the second clutch 38 into the engaged state. Bye.

The automatic gap adjustment mechanism 36 in the brake actuator 81 operates as follows when the gap exceeds a set value due to wear.

When the brake is applied, the protrusion 62 of the control member 55 comes into contact with the stopper 63 and the control member 55 is stopped at that position, but the first piston 31 and the rod 44
moves further leftward by a stroke corresponding to the amount of wear. At this time, the force transmitted to the push rod 35 via the protrusion 56 of the rod 44 and the first nut 50 is
It is transmitted to the nut 51 and moves the second nut 51 forward to the left against the second spring 54. As a result, the second nut 51 is disengaged from the control member 55 and receives an axial acting force in the right direction corresponding to the reaction force of the compression of the second spring 54, so that the male screw 49 of the push rod 35
, the screwing position with the push rod 35 moves to the right (toward the first piston 31 side), and then it meshes with the control member 55 and stops. The push rod 35, together with the rod 44, has therefore moved forward a greater distance than before. This extra forward distance corresponds to the amount of wear.

Next, when the brake is released, the first piston 3
1 retreats, the rod 44, the first nut 50, the push rod 35, and the second nut 5 move together with the first piston 31.
1. The control member 55 retreats to the right. When this retraction amount exceeds the predetermined stroke L (set value) of the control member 55, the protrusion 62 of the control member 55 moves to the stopper 6.
4, the control member 55, second nut 51, and push rod 35 are stopped at that position, but the first piston 31 and rod 44 are further retreated. At this time, the first ball 68 is held by the rod 44 in a state in which it protrudes into the groove 58, and moves from the state in which it meshes with the uneven surface 59 of the first nut 50 to the open side of the groove 58, that is, to the right in the figure. The teeth become misaligned. Therefore,
The first nut 50 is rotatable, and the first spring 52
The push rod 35 rotates along the male thread 49 of the push rod 35 , the screwing position with the push rod 35 moves to the right, and it stops at the position where the uneven surface 59 meshes with the first ball 68 . . This completes the automatic gap adjustment.

Further, manual release of the brake in this brake actuator 81 is performed as follows.

As described above, whether the brake is an air brake or a spring brake, the brake operating state is a state in which the first piston 31 moves forward with the push rod 35 to the left. When the first clutch 37 is released in this state, the first ball 68 can be displaced outward in the radial direction of the rod 44, and the first nut 50 can be rotated. Since the push rod 35 is receiving a force to retreat to the right by the return spring on the brake device side, it tends to retreat together with the first nut 50 and the second nut 51. The second nut 51 can be moved back together with the control member 55 in the forward position, and the first nut 50 receives a reaction force directed to the left from the protrusion 56 of the rod 44. As a result, the first nut 50 rotates by the amount that the push rod 35 retreats, allowing the push rod 35 to move backward, and the brake is released.

Next, when applying the brake, the first clutch 37 is brought into the engaged state, and then the first piston 31
And the second piston 32 or the first piston 31 is retreated to the brake release position. This retreat is similar to when the brake is released during the automatic gap adjustment described above, and the first ball 68 is out of mesh with the uneven surface 59 of the first nut 50, causing the first nut 50 to become a push rod. rotates along the male screw 49 of 35,
The screwing position with the push rod 35 moves to the right, and when the first piston 31 finishes retreating, the uneven surface 59 and the first ball 68 mesh with each other and stop at that position.

A second embodiment will be explained using FIG. 2. In the same figure, parts equivalent to those in the first embodiment are indicated by the same reference numerals, and their explanation will be omitted. The main differences from the first embodiment are that the brake actuator 82 is a single air brake cylinder and does not share a cylinder with the spring brake, and that the structure of the first clutch 83 is different.

The cylinder body 30a of the brake actuator 82 is the first cylinder body 30a.
An end wall is provided by removing the right half of the cylinder body 30 of the embodiment, and about one-third of the left side of the extension cylinder body is removed.

The first clutch 83 is provided with a pawl 85 that can be moved forward and backward from the rod 44 side in the radial direction on a serrated concavo-convex portion 84 provided on the outer periphery of the first nut 50, and an operating member 86 is provided on the pawl 85 for manual operation. It is formed to be able to be released or pneumatically released, and an operating member 86 connected to a pawl 85 is provided with a piston portion 87 and accommodated in a cylinder 88, and is provided with springs 89 and 90.

The spring 89 connects the operating member 86, and the spring 90 connects the claw 85.
The claws 85 are in engagement with the concavo-convex portions 84 of the first nut 50, and this is the engaged state of the first clutch 83. The connected state of this first clutch is
The nut 50 is locked against rotation in the forward direction to the left relative to the push rod 35, and is allowed to rotate when retreating to the right. That is, the direction of the sawtooth-shaped uneven portion 84 is determined.

The operating member 86 is operated by either pulling the end portion from the cylinder 88 or supplying pressurized air to the cylinder chamber 91 to disengage the claw 85 from the concavo-convex portion 84 . This is the first clutch 83
is in a free state. Then, by releasing the tension on the operating member 86 or by exhausting the pressurized air in the cylinder chamber 91, the operating member 86 and pawl 85 return to their original clutch engaged state.

In this brake actuator 82, the automatic gap adjustment operation by the automatic gap adjustment mechanism 36 and the brake release operation by the first clutch 83 are performed in the same manner as in the first embodiment.

A third embodiment will be explained using FIG. 3. In the figure, equivalent parts of the first embodiment are designated by the same reference numerals and their explanations will be omitted. The main difference from the first embodiment is that the first clutch 92 is connected to the first nut 50.
The other point is that the rod 44 is configured to connect and release between another rotating body 93 that meshes with the rod 44 side.

The rotating body 93 is provided with a large number of grooves 94 in the axial direction that engage with the first ball 68 along its outer circumference.
A meshing portion 95 that meshes with the rear side of the first nut 50 is provided on the left front side in the figure. This meshing portion 95 is the first
The nut 50 side has a bevel gear shape with small teeth, and the rotating body 93 side has a shape matching this. Rotating body 9
3, since the concave groove 94 and the first ball 68 engage with each other when the first clutch 92 is engaged, the first ball 68 is locked to the rod 44 side and cannot rotate, and when the first clutch 92 is released, the first ball 68 is engaged. Since the nut 68 can be displaced outward, it can rotate together with the first nut 50.

In this brake actuator 97, the automatic gap adjustment operation by the automatic gap adjustment mechanism 36 and the brake release operation by the first clutch 92 are performed in the same manner as in the first embodiment.

<Effects of the invention> According to this invention, a manual brake release mechanism can be easily added by providing the first clutch between the first nut and the rod side of the conventional automatic clearance adjustment mechanism. If the brake actuator is equipped with a conventional automatic clearance adjustment mechanism, it is only necessary to newly provide the first clutch part, and the first nut also serves as a part of the first clutch, so
The switch actuator can be equipped with both an automatic clearance adjustment function and a manual brake release function without increasing the size and cost.

[Brief explanation of the drawing]

Fig. 1 shows a first embodiment of this invention, a is a longitudinal cross-sectional side view of the upper half thereof, b is a partial cross-sectional plan view of the first nut and first clutch portion, and Fig. 2 is a second embodiment of this invention. An example is shown in which a is a longitudinal cross-sectional side view of the upper half of the
b is a partial cross-sectional view perpendicular to the axis of the first nut and the first clutch portion, FIG. 3 is a vertical cross-sectional partial view of the upper half showing the third embodiment, and FIG. 4 is a brake operation having a conventional automatic gap adjustment mechanism. FIG. 5 is a vertical side view showing an example of a conventional brake actuator having a manual release mechanism. 30, 30a...Cylinder body (main body), 31...
...First piston, 33... Spring for returning the first piston (return spring), 35... Push rod, 36... Automatic clearance adjustment mechanism, 37, 83, 92... First clutch, 40... Cylinder chamber, 44... Rod, 46
...(Extension part) Rod, 49...Male thread, 50...
...first nut, 51...second nut, 52...first spring, 54...second spring, 55...control member.

Claims (1)

[Claims for Utility Model Registration] A cylindrical rod provided inside the main body so as to be movable in the front and back direction moves forward by receiving a moving force,
The push rod, one end of which is inserted into the rod, is configured to advance through an automatic gap adjustment mechanism provided between the push rod and the rod to generate a braking force, and the automatic gap adjustment mechanism includes: A first
The nut and the second nut are screwed together, and the first nut is pressed backward from the rod side with the first spring, so that the rod side is engaged with the rod side so that rotation around the push rod is restricted, and the rod side is pushed forward from the rod side. The second nut is brought into contact from the front side with a control member which is provided so that a moving force directed toward is transmitted to the push rod, and which is provided between the second nut and the main body so as to be movable by a predetermined distance in the front and back direction. In the brake actuator, a second spring is provided between the second nut and the control member so as to mesh with each other so as to restrict rotation around the push rod and to maintain the meshed state. a first clutch that switches the meshing state between the nut and the rod side at least between a connected state in which rotation of the first nut is locked in a direction in which the first nut advances along the push rod and a released state in which the lock is released; A brake actuator characterized in that a brake actuator is provided between a first nut and the rod side.