JPH0711302B2 - Brake cylinder - Google Patents

Abstract

PURPOSE:To shorten the axial dimension by providing a common cylinder chamber between first and second pistons. CONSTITUTION:A first air brake piston 22 having the front side connected to a push rod 36 connected to a brake device and a second spring brake piston 23 having the front side capable of abutting against the rear side of first piston 22 are received in a cylinder body 21 slidably back and forth. Also, a section between the first and second pistons 22, 23 in the cylinder body 21 is formed in a cylinder chamber 24 having a supply and exhaust hole 45 for pressurized air. Further, a first a first spring 25 for returning piston 22 is provided on the front side of first piston 22 and a second spring 26 or a spring brake is provided at the rear side of second piston 23, while the second piston 23 is adapted to resist the working force of second spring 26. By this constitution can be shortened the axial dimension.

Description

Description: TECHNICAL FIELD The present invention relates to a brake cylinder mainly used in a rail vehicle and having two functions of a regular air brake and a parking spring brake.

<Prior Art> A conventional brake cylinder of this type includes US Pat. No. 4,084.
No. 0,875 specification and Japanese Patent Publication No. 47-9644, the outline of which is shown in FIG.

This brake cylinder supplies the pressure air from the first air source 2 to the first cylinder chamber 1 through the brake control device 3 and the first supply / discharge hole 4, thereby making it possible to perform the first air brake operation.
The piston 6 moves against the first spring 7 for returning the piston to the second
In the figure, it moves to the left, whereby the first push rod 8 is moved to the left, and a braking force corresponding to the supply air pressure is generated in the brake device (not shown). When the air supplied to the first cylinder chamber 1 is exhausted from the brake control device 3, the first piston 6 and the first push rod 8 are returned to the right by the first spring 7, and the brake is released.

This brake is a regular air brake and is used during normal operation, during which pressure air from another second air source 10 is supplied to the second cylinder chamber 9 by a solenoid valve 11, a double check valve 12, a second check valve.
It is supplied through the supply / discharge hole 13 and moves the second piston 14 to the right against the second spring 15 for spring braking, and penetrates the partition wall 16 from the second piston 14 to the first cylinder chamber. The second push rod 17 provided so as to reach 1 is also moved to the right, and the spring brake is maintained in a state not related to the conventional air brake.

When the pressurized air in the second cylinder chamber 9 is discharged from the solenoid valve 11, the second spring 14 moves the second piston 14 to the left, and the second push rod 17 pushes the first piston 6 to the left. Therefore, the spring brake acts.

This spring brake acts when the pressure air is not supplied to the first cylinder chamber 1, and does not act when the pressure air is supplied to the first cylinder chamber 1. A double check valve 12 is provided for this purpose. That is, in a state in which the pressurized air is supplied to the first cylinder chamber 1, even if the solenoid valve 11 is operated to exhaust the inside of the second cylinder chamber 9, the double check valve 12 causes the pressure of the first air source 2 to rise. Since the air is switched to be supplied to the second cylinder chamber 9, the air is not exhausted, so that the second piston 14 does not move to the left. This is designed so that the regular air brake and the spring brake do not work at the same time, so that excessive braking force will not cause a hazard to passengers and the wheels will slip and cause uneven wear. It is a consideration. Although not shown in the figure, the second piston 14 and the second piston 14 are provided as a device for loosening the spring brake in the operating state by a manual operation in order to move the parked vehicle to which the spring brake is applied. A clutch is provided between the two push rods 17 so that both can be manually separated and operated from the outside.

<Problems to be Solved by the Invention> In the above-mentioned conventional brake cylinder, the first cylinder for the air brake and the second cylinder for the spring brake are simply connected in series via the partition wall 16. , First
Spaces required for the strokes of the piston 6 and the second piston 14 are separately required in the longitudinal direction, and there is a problem that the size becomes large.

Further, since the double check valve 12 is inserted in the brake pipe, there is a problem that the pipe becomes complicated and failure factors increase to deteriorate the reliability of the brake.

Further, since it is necessary to supply the compressed air to the second cylinder chamber 9 in order to release the spring brake, there is a problem that the consumption of the compressed air is increased and the energy loss is large.

<Means for Solving the Problems> The means of the present invention includes a first piston for an air brake in which a push rod connected to a brake device is connected to the front side in a cylinder body, and a front side to the rear side of the first piston. A cylinder chamber that accommodates a second piston for spring brake, which can come into contact with the side, slidably in the front-rear direction, and has a supply / discharge hole for pressurized air between the first piston and the second piston in the cylinder body. The first spring for returning the first piston is provided on the front side of the first piston, the second spring for spring braking is provided on the rear side of the second piston, and the second piston acts on the second spring. It is characterized in that it is provided with an engagement / disengagement means capable of being held in the retracted position against the pressure and released.

<Operation> In a state in which pressurized air is supplied from the supply / discharge holes into the cylinder chamber, the first piston moves forward against the first spring for returning the first piston, and the second piston functions as the second spring for spring braking. It is in a retracted position against it. In this state, the engaging / disengaging means can lock the second piston. When the compressed air in the cylinder chamber is exhausted while the second piston is locked in the retracted position, the first piston retracts due to the acting force of the first spring and comes into contact with the front side of the second piston. Therefore, in this state, the first piston can be moved forward and backward by supplying and discharging the pressure air into the cylinder chamber, and by adjusting the pressure of the supplied pressure air, the first piston can be adjusted to that pressure. The forward position can be controlled accordingly. When the push rod is connected to the first piston, a desired braking force can be generated in the brake device via the push rod.

Further, when the second piston is released by the engagement / disengagement means in a state where the cylinder chamber is exhausted and the first piston is retracted, the second piston moves forward together with the first piston by the action force of the second spring. As a result, the spring brake is activated. Even if the second piston is released while the pressurized air is being supplied to the cylinder chamber, the second piston does not come into contact with the first piston due to the air pressure, and the first piston is controlled by the air pressure inside the cylinder chamber. To keep

<Example> One example will be described with reference to FIG. In the figure, 21
Is a cylinder body, 22 is the first piston for the air brake, and 23
Is the second piston for the spring brake, 24 is the cylinder chamber, 25
Is a first spring for returning the first piston 22, 26 is a second spring for spring braking, and 27 is an engaging / disengaging means.

The cylinder body 21 is formed by providing a front end wall 30 and a rear end wall 31 to a cylindrical body having a slightly smaller diameter at both front and rear ends, and the inner cylinder 32 is directed toward the inner side of each of the end walls 30 and 31. , 33 are projectingly provided, and the inner holes of the inner cylinders 32, 33 communicate with the inside and outside of the cylinder body.

The first piston 22 is accommodated in the cylinder body 21 so as to slide in the front-rear direction, is formed in a cup shape open to the front side, and is in contact with the inner peripheral surface of the cylinder body 21 in the front half portion of the outer periphery thereof. A cylindrical push rod connecting portion 34 that is slidably fitted in the inner cylinder 32 is provided at the center of the front side. The push rod connecting portion 34 is connected to a rear end portion of the push rod 36, which is inserted into the inner hole 35 from the front side, by a clutch 37 that can be manually released from the outside. The structure of the clutch 37 is the same as the clutch in Japanese Patent Application No. 61-71602 previously proposed as a spring brake cylinder.

The clutch 37 connects and disconnects the first piston 22 and the push rod 36 with respect to the axial movement, and the connecting portion 34.
It is composed of two balls 38 held by the control member 39, a control member 39 for controlling the position of the balls 38, and a recess 40 provided in the push rod 36. The control member 39 has a cylindrical shape, one end of which is fitted to the outer periphery of the ball holding portion of the connecting portion 34 and the other end of which reaches the front end of the cylinder body 21, and which is located around the axis with respect to the first piston 22 side. It is rotatable. The inner peripheral surface of the control member 39 outside the position of the ball 38 is provided with the ball 38 in a recess 40 as shown.
A portion to be restrained inside and a recessed portion that allows the ball 38 to be displaced outward while the control member 39 (not shown) is slightly rotated are formed. Reference numeral 41 in the drawing denotes an operation member, which has a claw 42 engaged with the control member 39 and extends outside the cylinder body 21,
By pulling this, the control member 39 rotates a little and the clutch 37 is brought into the separated state. That is, the recess of the control member 39 is located outside the ball 38, and the ball 38 can be removed from the recess 40, and the axial connection between the push rod 36 and the first piston 22 is separated. The micro switch indicated by 43 in the drawing has the first surface due to the unevenness provided in the axial direction of the outer surface of the control member 39.
Forward position of piston 22, backward position, coupling of clutch 37,
The disconnection state can be detected.

The second piston 23 is housed so as to be positioned on the rear side of the first piston 22 and slidable in the cylinder body 21 in the front-rear direction, and is formed in a cup shape that is open to the rear side, and has a rear central portion. Has a rod-shaped locked portion 44 that is slidably fitted in the inner cylinder 33.

The cylinder chamber 24 has a rear surface of the first piston 22 and a second piston.
A position that is formed by the front surface of 23 and the inner peripheral surface of the cylinder body 21, and that is open to the cylinder chamber 24 at all times until the first and second pistons 22 and 23 move backward from the illustrated position to reach the stroke end. First supply / discharge hole for supplying / discharging compressed air
45 is provided.

The first spring 25 is a coil spring for returning the first piston 22, and is provided between the front end wall 30 of the cylinder body 21 and the first piston 22.

The second spring 26 is a coil spring for spring braking, is provided between the rear end wall 31 of the cylinder body 21 and the second piston 23, and generates a braking force against the acting force of the first spring 25. It is a powerful one. The spring force of the second spring 26 is usually set to a value obtained by multiplying the emergency brake air pressure when the vehicle is empty by the effective area of the second piston 23.

The engagement / disengagement means 27 is adapted to lock the second piston 23 in the retracted position, and includes the sleeve 46, the ball 47,
It is formed of a tubular body 48, a third spring 49, a lid body 50 and the like. The sleeve 46 is screwed to the front end of the inner cylinder 33, the locked portion 44 of the second piston 23 is fitted into the inner hole of the sleeve 46, and the rear portion holds two balls 47. Second in the retracted position shown
A concave groove 51 with which the ball 47 engages is formed at a position corresponding to the ball 47 of the locked portion 44 of the piston 23. Behind the position of the ball 47, there is formed a gap between the outer peripheral surface of the sleeve 46 and the inner cylinder 33 into which the front end of the cylinder 48 enters, and the ball 47 is covered at the position where the illustrated cylinder 48 advances. Groove 51 of engagement part 44
To be engaged with. The cylindrical body 48 is formed as a piston by forming the rear end portion in an enlarged manner, is fitted in a portion in which the rear half of the inner hole of the inner cylinder 33 is enlarged, and is pressed rearward by the third spring 49. Close the rear end of the inner hole of the inner cylinder 33 with the lid 50,
A space between 48 and the lid 50 is formed in a pilot chamber 52, and the lid 50 is provided with a second supply / discharge hole 53 for supplying / discharging the pilot air. The state shown in the figure is a state in which pressurized air is supplied to the pilot chamber 52, and the cylindrical body 48 is advanced against the third spring 49 and restrains the ball 47 in the position where it is engaged with the concave groove 51. The two pistons 23 are locked so as not to move forward. If the pressurized air in the pilot chamber 52 is discharged from this state, the cylinder 48
Is retracted by the acting force of the third spring 49, whereby the ball 47 can be displaced outwardly, and accordingly, the lock is released.

The brake cylinder configured in this way is
Are connected, and pressurized air is supplied from the first supply / discharge hole 45 into the cylinder chamber 24 and from the second supply / discharge hole 53 into the pilot chamber 52, whereby the second piston 23 is disengaged to the retracted position. After being locked by the means 27, the cylinder chamber
Operate the air brake by supplying and exhausting pressurized air to 24 only. The operating state of the air brake is a state in which pressurized air is supplied into the cylinder chamber 24 and the first piston 22 moves forward together with the push rod 36. The operating state of the spring brake used during parking is that the locking means 27 releases the second piston 23 when the pressurized air in the pilot chamber 52 is discharged, whereby the second piston 23 is used for braking. It is in a state of being advanced together with the first piston 22 and the push rod 36 by the acting force of the second spring 26. When it is necessary to release the spring brake by an operation from the outside with respect to a parked vehicle on which such a spring brake acts, when the clutch 37 is disengaged, the shaft of the first piston 22 and the push rod 36 is separated. Since the directional connection is released, the push rod 36 is freely displaced rearward, and the spring brake is released while the second piston 23 is being advanced by the second spring 26.

In the above embodiment, the first piston 22 and the second piston 23
Although the outer diameters of and are illustrated as being the same, they do not necessarily have to be the same and may have different outer diameters.

<Effects of the Invention> According to the present invention, the cylinder chamber common to the first and second pistons is formed between the first piston and the second piston, and the partition wall does not exist. Therefore, the dimension in the axial direction can be formed smaller than that in the related art. Moreover, by supplying and discharging the pressurized air to and from one cylinder chamber, the first piston and the second piston
Since the piston can be operated and the normal air brake and the spring brake do not act in the state of being added at the same time, it is not necessary to provide a double check valve, and reliability is improved. Further, the air consumption amount is smaller than that in the conventional one in which the air brake cylinder and the spring brake cylinder are provided separately, and energy can be saved accordingly.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an embodiment of the present invention, and FIG. 2 is a partial vertical sectional side view showing a schematic structure of a conventional brake cylinder and its piping. 21 ... Cylinder body, 22 ... First piston, 23 ... Second piston, 24 ... Cylinder chamber, 25 ... First spring, 26 ... Second spring, 27 ... Engaging means, 36 ... Push rod, 45 ... Supply / discharge hole (first supply / discharge hole).

Claims (1)

[Claims] 1. A first piston for an air brake in which a push rod connected to a brake device is connected to the front side in a cylinder body, and a second piston for a spring brake in which the front side can come into contact with the rear side of the first piston. A piston is housed so as to be slidable in the front-rear direction, a space between the first piston and the second piston in the cylinder body is formed in a cylinder chamber having a supply / discharge hole for pressurized air, and a first chamber is provided on the front side of the first piston. A first spring for returning one piston is provided, a second spring for spring braking is provided on the rear side of the second piston, and the second piston is locked in the retracted position against the acting force of the second spring. A brake cylinder provided with an engaging / disengaging means capable of being released.