JPH02203027A - Unit brake device - Google Patents

Abstract

PURPOSE:To enable the angle made between a push rod and a hanging member to be kept constant in a brake operating condition independently of the wear of the brake shoe by slidably supporting end of the hanging member through a guide groove which is parallel to the moving direction of the push rod, and by connecting the hanging member to the brake head by means of an elastically expandable connecting rod. CONSTITUTION:The direction of a guide groove 26 is parallel to the advancing or receding direction of a push rod 22. In the inside of the guide groove 26, a sliding piece 33 is slidably housed, and thereto the upper end part of a hanging member 25 is turnably connected. The hanging member 25 and the guide groove 26 are at right angles to each other. A connecting rod 27 connects the hanging member 25 and a brake head 23 via pins 35a, 35b. In the connecting rod 27, in the inside of the cylindrical part 36 on one side, the rod part 37 on the other side is inserted, and a coil spring 41 energized in a compressed condition is housed in the inside of a spring housing part 38, so that it can be expanded or contracted by a force greater than a prescribed value between pins 35a and 35b in either expanding or contracting direction. In the case where the push rod 22 moves forward at the time of brake operation, since the upper part of the hanging member 25 moves along the guide groove 26, the angle between the push rod 22 and the hanging member 25 remains constant.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a unit brake device for a railway vehicle. The system is designed to obtain a more stable braking force by ensuring uniform contact between the wheels and the road surface.

<Conventional technology> As a conventional unit brake device for railways, NABCO Technical Report (published by the Technology Development Department of Japan Air Brake Co., Ltd.) N
o, [There is a TG-type tread brake unit described on pages 54 and 55 of i5. The schematic structure of the unit is shown in Fig. 5. In the figure, 1 is the main body, 2 is a push rod,
3 is a brake shoe head, 4 is a brake shoe, and 5 is a hanging member. Main body 1
An air cylinder 6 is provided in which 7 is a piston, 8 is a return spring, and 9 is a pressurized air supply/discharge port. The rod 7a of the piston 7 is connected to the lever IO, and the lever Ill is connected to the shaft 1.
1 to the main body 1, and is connected to the push rod 2 via a spherical seat in the middle. The push rod 2 has a brake shoe head 3 pivotally supported by a pin 12 at its tip protruding from the main body 1, and the lower end of the hanging member 5 is also connected to the pin 12. The upper end of the hanging member 5 is pivotally supported by a pin 14 on a protrusion 13 protruding from the main body l. The push rod 2 is gradually extended by the operation of a gap adjustment mechanism (not shown) as the brake shoes 4 and wheels 15 wear out.

When pressurized air is supplied to the air cylinder 6, the piston 7 moves to the left in the figure against the spring 8, advances the push rod 2 toward the wheel IS via the lever 10, and moves the brake shoe 4 toward the wheel 15. It is pressed through the brake shoe head 3 to apply the brake. When the pressurized air in the air cylinder 6 is exhausted, the piston 7 is moved back to the right by the spring 8, and the brake is released.

When the brake shoe 4 is pressed against the rotating wheel 15 with a force F, a braking force FB in the opposite direction to the rotational direction acts on the wheel 15 due to friction, and a brake force FB of the same magnitude as the brake force FB is applied to the brake shoe 4 due to friction. A reaction force F2 having the opposite direction acts. This reaction force F
2 is received by the main body l via the hanging member 5. Since the brake shoe 4 wears out with use, the angle of the hanging member 5 with respect to the push rod 2 gradually changes as the brake shoe 4 changes from a new state to a worn state that requires replacement. Taking this change into consideration in advance, the hanging member 5 and the push rod 2 are made to form a right angle in the middle of the changing angle range 2β as shown in the figure. This is designed to reduce changes in the forward and backward directions of the push rod 2, which moves forward and backward while being restrained by the hanging member 5.

Separately, the brake head of a conventional unit brake device is as described in Japanese Utility Model Publication No. 63-42186,
A support structure with a leaf spring interposed therebetween makes it possible to adjust the inclination with respect to the push rod.

This is to ensure that the arcuate braking surface of the brake shoe and the arcuate road surface of the wheel are in uniform contact without uneven contact.

<Problems to be Solved by the Invention> In the conventional unit brake device shown in FIG. 5, even if the force F1 is constant, the angle of the hanging member 5 is 2.
There is a problem in that the braking force F1 differs due to the β change. To explain this point, when the hanging member 5 is perpendicular to the push rod 2, the direction of the reaction force F2 that the hanging member 5 receives coincides with the direction of the hanging member 5, so the reaction force F2 causes a force parallel to the pressing force F. No component force (parallel to push rod 2) is generated.

However, when the brake shoe 4 is new (the state shown by the solid line in Fig. 5), the hanging member 5 is tilted to one side by an angle β from the state perpendicular to the push rod 2, so as shown in Fig. 6(a). Then, the reaction force F2 generates a component force F3 that is parallel to and opposite to the pressing force F1. F is the component force along the hanging member 5.

In addition, when the brake shoe 4 is worn out and is in the state m just before replacement (the state shown by the chain line in the figure on p. Therefore, as shown in FIG. 6(b), the reaction force F2' produces component forces F,' parallel to and in the same direction as the pressing force F.

F4' is a component force along the hanging member 5. If we calculate the magnitude of the braking force F8 using the coefficient of friction between the wheel 15 and the brake shoe 4 as a pot, the magnitude is equal to the reaction force F2, so as shown in Fig. 6 (
In the case of a) and the case of FIG. 6(b), the degree of wear of the brake shoe 4 is medium and the hanging member 5 is
In the state perpendicular to push rod 2 (state of β = 0), F2 = F
,'=μF, so the value of F2 and equation (1,)
, (2) with the values of F2 and F2' are respectively, the former being smaller than l and the latter larger than l. Therefore, the magnitude of the braking force FB gradually increases as the brake shoe 4 wears.

Such a change in braking force can cause skidding because the speed of modern vehicles is increasing and the braking force must be set large until the skid limit is reached. If the wheels skid, a flat portion will form on the wheels, which will cause unpleasant noises and damage the rails. And repairing such wheels costs a lot of money.

In addition, the adjustment structure of the brake head described in Publication of Utility Model Publication No. 63-42186 is due to errors in adjustment during installation, and the loss of the legitimate brake head due to the reaction force from the wheel during the application of braking force. If the braking surface of the wheel does not come into uniform contact with the road surface of the wheel, there is a problem that the wheel remains in a one-handed state.

An object of the present invention is to maintain a constant angle between the push rod and the hanging member in a braking state, regardless of wear of the brake shoe.

<Means for Solving the Problems> The present invention provides a unit brake device as described above, in which the supporting portion on the main body side of the hanging member is formed in a guide groove portion in a direction parallel to the moving direction of the push rod, and a One end of the hanging member is slidably supported, the hanging member and the brake shoe head are rotatably coupled to the push rod tip, and the hanging member and the brake shoe head are placed at a position apart from the push rod tip. It is characterized by being connected by an elastically expandable connecting rod.

Function> When the push rod moves forward from the retreated position to perform a braking action, it moves forward together with the hanging member, and the end of the hanging member on the main body side also moves forward along the guide groove. At this time, the distance that the hanging member moves forward on the guide groove side may be less than the distance that the push rod moves forward, but in this case, the inclination is controlled so that it follows the wheel tread while being pressed against the brake shoe or wheel. Therefore, the suspension member is caused to follow the movement of the brake shoe head via the connecting rod, and in the braking operation state, the push rod and the suspension member are at a constant angle. Therefore, even if the brake shoe wears and the forward position of the push rod in the braking state changes, the angle between the hanging member and the push rod does not change, and the braking force does not change.

In addition, when the push rod moves forward and the brake shoes start contacting the wheel tread, only the upper or lower part of the brake shoe comes into contact with the wheel tread, and by moving the push rod roughly forward, the entire braking surface of the brake shoe is uniformly applied to the wheel tread. If the brake reaction force acting on the suspension member increases until it is pressed against the road surface, and the suspension member stops moving along the guide groove with a small distance remaining, the connecting rod will expand and contract. to allow movement of the brake shoes.

Do not become one-handed. Even if the hanging member stops, the tendency is the same every time and the tendency does not change due to wear of the brake shoe, so there is no change in the angle between the hanging member and the push rod.

<Example> An example of the present invention will be described with reference to FIGS. 1 to 4. In the figure, 21 is a main body, 22 is a push rod 23 is a brake shoe head, 24 is a brake shoe, 25 is a hanging member, 26 is a guide groove portion, 2
7 is a connecting rod.

The main body 21 has cylinders, screws, return springs, pressurized air supply and exhaust holes, etc. inside the main body 21, as in the conventional device shown in FIG. 5, and illustrations of these are omitted. be. The supply of pressurized air causes the schematically shown piston rod 29 to drive the lever 30 and to advance the pusher n22 towards the center of the wheel 15.

The push rod 22 has a gap adjustment mechanism inside the main body 21, as well as the conventional one, and the push rod 22 has a gap adjustment mechanism inside the main body 21.
As the wheel 15 wears, it is automatically extended gradually toward the front brake shoe 24. A brake shoe head 23 and a hanging member 25, which will be described next, are pivotally coupled to the externally protruding tip of the main body 21 by means of a pin 31.

The brake shoe head 23 is the same as the conventional brake shoe head 23 in that it is attached so that the brake shoe 24 can be attached and removed, but a connecting rod 27 is provided in place of the conventional brake shoe head inclination adjustment mechanism.

As shown in FIG. 1, the lower end of the hanging member 25 is pivotally connected to the tip of the 5-push rod 22 via a pin 31, and the upper end is supported by the guide groove portion 26. The guide groove portion 26 is provided inside two paired protrusions 32 on both sides that protrude from the main body 21 toward the wheel 15, and its direction is parallel to the direction in which the push rod 22 moves forward and backward. As shown in Figures 2 and 3,
A sliding piece 33 is slidably accommodated in each of the guide grooves 26, and the upper end of the hanging member 25 is rotatably connected to the sliding piece 33 via a connecting shaft 34. This hanging member 2
5 and the guide groove portion 26 are at right angles.

As shown in FIG.
a, connected via 35b. As shown in FIG. 4, the structure of the connecting rod 27 is such that one rod-shaped portion 37 fits into the other cylindrical portion 36, and a spring housing portion 38 is formed between the fitting surfaces of both. Annular spring washer 3 inside
9.40, the coil spring 41 is biased into a pressure wire state and accommodated. With this structure, the bins 35a,
The space between 35b expands and contracts with a force equal to or greater than a predetermined value both in the direction of stretching and in the direction of contracting.

The unit brake device configured in this way pushes the lower end of the hanging member 25 and the brake shoe head 23 forward through the pin 31 when the push rod 22 moves forward during braking, and at this time, the upper part of the hanging member 25 pushes forward through the bottle 31. moves along the guide groove 26, the angle between the push rod 22 and the hanging member 25 remains constant, and the brake shoe 24 comes into contact with the wheel 15 to perform a braking action. When the brake shoe 24 starts to contact the wheel 15, even if the upper end or lower end of the brake shoe 24 first contacts the wheel for some reason, the brake shoe head 23 and the brake shoe 24 will move further as the push rod 22 moves forward. The wheel 1 rotates around the bin 31 due to the reaction force received from the initial contact position, and the entire braking surface
It comes into contact with 5. At this time, due to the presence of the connecting rod 27, the hanging member 25 also rotates, or when the hanging member 25 cannot rotate, the connecting rod 27 extends or contracts, allowing the brake shoe head 23 and the brake shoe 24 to rotate. be done.

<Effects of the Invention> According to the invention set forth in claim (1), even if the push rod is edged out due to wear of the brake shoes, the angle between the hanging member and the push rod is always kept constant, so that the reaction of the braking force is reduced. The direction of the hanging member that receives the force is constant with respect to the direction of the reaction force, and the effect of suppressing variations in braking force can be obtained.

Further, the entire braking surface of the brake shoe is evenly pressed against the road surface of the wheel, thereby achieving the effect of preventing one-sidedness of the brake and unilateral wear of the brake shoe.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B in FIG.
Fig. 4 is an enlarged sectional view of the connecting rod of the same embodiment, Fig. 5 is a schematic side view of the conventional unit brake "An", Fig. 6 (a)
, (b) are vector diagrams illustrating that different force components are generated depending on the brake reaction force or rotation of the hanging member in the apparatus shown in FIG. 5. 21... Body, 22... Push rod, 23... Brake shoe head, 24... Brake shoe, 25... Hanging member, 2
6...Guide groove portion, 27...Connecting rod, 31...
·bottle. Patent applicant: Japan Air Brake Co., Ltd.
Person Tetsu Shimizu and 2 others 1st
times

Claims (1)

[Claims] (1) A push rod that protrudes from inside the main body and is provided to move forward and backward in the projecting direction and transmits the output of the cylinder section to the brake shoe head, a brake shoe head attached to the tip of this push rod, and one end attached to the main body. In the unit brake device, the suspension member is supported by a supporting portion on the side and the other end is connected to the tip of the push rod so as to be approximately perpendicular to the supporting portion on the main body side in the moving direction of the push rod. one end of the suspension member is slidably supported in the guide groove, the suspension member and the brake shoe head are rotatably coupled to the tip end of the push rod; A unit brake device characterized in that the member and the brake shoe head are connected by a connecting rod that is elastically expandable and retractable at a position apart from the tip of the push rod.