KR102484861B1 - Variable vibration damping structure of pneumatic drum brake - Google Patents

Abstract

The present invention discloses a variable vibration damping structure of a pneumatic drum brake. A variable vibration damping structure of a pneumatic drum brake according to one embodiment of the present invention includes a link mechanism interlocking with a first guide pin provided in a linearly moving push rod; It is configured to include a mass portion moving along the chamber mounting bracket by the link mechanism, and a second guide pin and a third guide pin connected to the link mechanism to guide the mass portion moving along the chamber mounting bracket.

Description

Variable vibration damping structure of pneumatic drum brake {VARIABLE VIBRATION DAMPING STRUCTURE OF PNEUMATIC DRUM BRAKE}

The present invention relates to a variable vibration damping structure of a pneumatic drum brake, and more particularly, to a variable vibration damping structure of a pneumatic drum brake having a structure capable of extending life and improving safety by damping vibration generated during brake operation. it's about

The parking brake device used when parking or temporarily stopping a vehicle is one of the important safety devices. When braking, the brake is quickly applied to obtain parking braking power, while when the vehicle starts, the parking brake is quickly released. It is required to do In addition, since the braking time depends on the time required for the braking pressure of the parking brake to reach the maximum value, the shorter this time is, the shorter the braking time is, and the release time is the time required for the braking pressure to reach the minimum value. The shorter the time, the shorter it is.

In general, drum brakes that generate braking force by friction with a drum rotating together with a wheel include a hydraulic type using hydraulic pressure and a mechanical type using a parking brake lever provided on one side of a driver.

When a mechanical drum brake is used as a parking brake of a luxury passenger car, it is used in combination with a caliper disc brake for hydraulic pressure braking of a rear wheel.

On the other hand, there is a center brake device that maintains a stopped state by pulling the brake lever and pressurizing the brake drum to the gear transmission output shaft, and a pneumatic parking brake device that obtains parking braking force with pneumatic pressure by installing a cam and a slack adjuster in the drum type wheel brake device. .

Describing the operation of the conventional pneumatic parking brake device, when the driver pulls the parking brake lever, the release valve operates the pneumatic operation valve. At this time, the compressed air in the brake chamber is discharged to the release valve to operate the parking brake. When the lock state of the parking brake lever is released when the vehicle starts, the pneumatic operation valve is operated, and the compressed air waiting at the valve inlet fills the brake chamber through the release valve, and the stop state is released.

The drum brake is applied to and used in the rear brake system of automobile braking devices, and is composed of parts such as a shoe that generates frictional force inside a cylindrical drum and a wheel cylinder that enlarges its diameter to connect to the inner surface of the drum.

1 is a schematic diagram of a conventional pneumatic drum brake, and FIG. 2 is a schematic diagram showing a damaged portion of the conventional pneumatic drum brake of FIG. 1 .

1 and 2 together, the conventional pneumatic drum brake includes a chamber 13, a push rod 12 connected to the chamber 13 and performing linear motion, and a slack for mounting the push rod 12. A chamber mounting bracket 10 for fixing the stud 11, the push rod 12 and the slack adjuster 11, an anchor mounting bracket 20 connected to the chamber mounting bracket 10, the anchor mounting bracket ( 20) is configured to include an S cam shaft 22 that drives the S cam shaft 22, a lining 23 located outside the S cam shaft 22, and a drum 21 that rotates while surrounding the outside of the lining.

In this structure, the chamber mounting bracket 10 and the chamber 13 connected thereto, the push rod 12 and the slack adjuster 11 serve as vibration sources, but the chamber mounting bracket 10 connected to the anchor mounting bracket 20 ), the vibration is amplified by In addition, it is connected to the axle by the anchor mounting bracket 20, and microvibrations are generated on the friction surface due to friction between the drum 21 and the friction material during braking, which becomes an excitation source.

That is, in the friction brake, the vehicle speed is reduced by the resistance generated by the friction between a rotating body such as a drum and a friction material such as a lining. Since it has a shape like a cantilever, vibration can be greatly amplified compared to other types of brakes. This is a problem in that excessive stress is generated in a portion connected to the anchor mounting bracket 20 while the chamber mounting bracket 10 vibrates up and down.

3 is a graph showing the amount of vibration when excessive vibration is applied in the related art.

Referring to FIG. 3 , damage occurs at a portion where the chamber mounting bracket and the anchor mounting bracket are connected. As shown in the drawing, when excessive vibration occurs, the amount of deformation increases by 38.7 times and the amount of vibration increases by 7.2 times.

That is, during braking, frictional vibration is amplified in the chamber mounting bracket, causing damage to the chamber at the end of the chamber mounting bracket due to excessive vibration, which affects the lifespan and quality of parts, resulting in a problem that impairs safety do.

Republic of Korea Patent Publication No. 10-2006-0063092

An embodiment of the present invention is a variable vibration damping structure of a pneumatic drum brake that can extend the life of the brake and improve safety by preventing excessive vibration from occurring in the chamber at the end of the chamber mounting bracket in order to overcome the problems of the prior art. want to provide

According to one aspect of the present invention, in the pneumatic drum brake, a link mechanism that interlocks with a first guide pin provided in a push rod for linear motion; a mass portion moved along the chamber mounting bracket by the link mechanism; A second guide pin connecting the link mechanism and the mass part and a third guide pin connecting the chamber mounting bracket and the link mechanism so that the mass part moves along the chamber mounting bracket.

The link mechanism may have a structure in which two plate-like members are spaced apart from each other and the two plate-like members are connected by a coupling pin.

The link mechanism can convert the linear motion of the push rod into rotational motion.

The link mechanism may have a structure in which a guide pin guide hole is bored to the inside.

The second guide pin and the third guide pin may have a structure that is spaced apart from each other.

The third guide pin is connected to the chamber mounting bracket and can serve as a support point during linear motion of the push rod.

A guide groove through which the mass unit moves may be formed at one side of the chamber mounting bracket.

The mass part may be coupled to a rod part connected to the second guide pin and the third guide pin.

The mass portion may be located below the guide groove of the chamber mounting bracket during non-braking.

The mass portion may have a structure that rises along the guide groove of the chamber mounting bracket during braking.

According to one embodiment of the present invention, the variable vibration damping structure of the pneumatic drum brake prevents excessive vibration from occurring at the end of the chamber mounting bracket connected to the anchor mounting bracket, thereby preventing excessive stress from occurring in the anchor mounting bracket. It can provide the effect of extending life and improving safety.

1 is a schematic diagram of a conventional pneumatic drum brake.
2 is a schematic diagram showing a damaged portion of the conventional pneumatic drum brake of FIG. 1;
3 is a graph showing the amount of vibration when excessive vibration is applied in the related art.
4 is a schematic diagram of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention.
5 is a partially enlarged schematic diagram of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention.
6 is a schematic diagram illustrating a case in which a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention is not braking.
7 is a schematic diagram showing a case of weak braking of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention.
8 is a schematic diagram showing a case of strong braking of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention.

Embodiments described below are provided so that those skilled in the art can easily understand the technical idea of the present invention, and the present invention is not limited thereto. In addition, matters represented in the accompanying drawings may be different from those actually implemented in the drawings schematically illustrated to easily explain the embodiments of the present invention.

It should be understood that when a component is referred to as being connected or connected to another component, it may be directly connected or connected to the other component, but other components may exist in the middle.

And "connection" here includes a direct connection and an indirect connection between one member and another member, and may mean all physical connections such as adhesion, attachment, fastening, bonding, and coupling.

In addition, expressions such as 'first and second' are expressions used only to classify a plurality of components, and do not limit the order or other characteristics between the components.

Singular expressions include plural expressions unless the context clearly dictates otherwise. The terms "include" or "having" are intended to mean that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and that one or more other features or numbers, It can be interpreted that steps, actions, components, parts, or combinations thereof may be added.

4 is a schematic diagram of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention, and FIG. 5 is a partially enlarged schematic diagram of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention, 6 is a schematic diagram showing a case in which a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention is not braked, and FIG. 7 is a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention. 8 is a schematic diagram showing a case of weak braking of , and FIG. 8 is a schematic diagram showing a case of strong braking of a variable vibration damping structure of a pneumatic drum brake according to an embodiment of the present invention.

4 to 8 together, the variable vibration damping structure 100 of the pneumatic drum brake according to the present invention includes a drum rotating together with a wheel, a lining provided to be in close contact with the drum, and a brake pedal In a pneumatic drum brake equipped with a cylinder that is operated when stepped on, and a piston rod provided in the cylinder and generating braking force by bringing the lining into close contact with the drum, the first guide pin 131 provided on the push rod 140 that moves linearly ) and a link mechanism 110 interlocking, a mass part 120 moving along the chamber mounting bracket 150 by the link mechanism 110, and a third connecting the link mechanism 110 and the mass part 120. 2 guide pins 132 and the third guide pin 133 connected to the link mechanism 110 so that the mass portion 120 moves along the chamber mounting bracket 150.

The link mechanism 110 according to the present invention is made of a plate-like member, and the link mechanism 110 has two plate-like members connected by a coupling pin 114 and spaced apart from each other.

In addition, the link mechanism 110 converts the linear motion of the push rod 140 into rotational motion, and the link mechanism 110 has a guide pin guide hole 116 drilled inside, and the guide pin guide hole 116 is formed with a width corresponding to the diameter of the first guide pin 131, and the first guide pin 131 moves along the guide pin guide hole 116. An operational relationship in which the first guide pin 131 moves along the guide pin guide hole 116 will be described in detail below.

In the above structure, the link mechanism 110 has coupling holes coupled to the second guide pin 132 and the third guide pin 133, respectively, and the second guide pin and the third guide pin ( 133) are spaced apart from each other. Here, the third guide pin 133 is connected to the chamber mounting bracket 150 and the link mechanism 110 together to serve as a support point during the linear motion of the push rod 140, centering on the third guide pin 133. will rotate

Here, the mass part 120 has a hemispherical shape and is coupled to the rod part 122 connected to the second guide pin 132 and the third guide pin 133 .

The mass part 120 moves along a guide groove 152 formed on one side of the chamber mounting bracket 150 in a vertical direction with respect to the ground, and the mass part 120 moves along the chamber mounting bracket 150 during non-braking. It is located at the bottom of the guide groove 152 of ) and is a structure that rises along the guide groove 152 of the chamber mounting bracket 150 during braking.

Specifically, when explaining the principle that the mass part 120 rises or falls along the guide groove 152 of the chamber mounting bracket 150, in the friction brake system, the rotational body generated through friction with the friction material Reduce vehicle speed with resistance.

In particular, pneumatic S-cam drum brakes used in commercial vehicles such as large trucks or buses have a structure like a cantilever, unlike other braking systems. Therefore, when the rotating body and the friction material rub, frictional vibration is generated on the frictional surface. In particular, since the S-cam brake has a cantilever shape, the vibration is greatly amplified compared to other types of brakes.

Therefore, as a principle of reducing the vibration frequency (f), which is inversely proportional to this by increasing the mass (m) of the vibrating unit according to the vibration equation as shown below, the vibration amplification during braking is suppressed as a variable structure according to the mass.

Referring to the drawings of FIGS. 4 to 8 together and describing the operating relationship of the variable vibration damping structure of the pneumatic drum brake according to one embodiment of the present invention, the chamber mounting bracket 150 is an actuator such as a chamber and an anchor mounting bracket The fixed ends are connected, and the push rod 140 connected therewith performs linear motion, but the link mechanism 110 converts the linear motion of the push rod 140 into rotational motion.

Specifically, the first guide pin 131 formed on one side of the push rod 140 reciprocates according to the linear motion of the push rod 140, but the first guide pin 131 is a link mechanism 110 It moves reciprocally along the guide pin guide hole 116 formed on the inside of the.

When the first guide pin 131 reciprocates through the guide pin guide hole 116, the link mechanism 110 rotates. At this time, the link mechanism 110 is made of a plate-like member, and the link mechanism 110 is spaced apart from each other by connecting two plate-like members by a coupling pin 114.

In addition, the link mechanism 110 is coupled to the second guide pin 132 and the third guide pin 133 spaced apart from each other, and when the link mechanism 110 rotates, the rod part connected thereto 122 rotates, and the mass part 120 connected to the rod part 122 moves.

In this case, the mass part 120 reciprocates along the guide groove 152 formed on one side of the chamber mounting bracket 150 .

In this structure, when weak braking is applied, the first guide pin 131 connected to the push rod 140 moves along the guide pin guide hole 116, and the guide pin guide hole 116 is formed. The link mechanism 110 rotates clockwise, and the mass portion 120 rises along the guide groove 152 of the chamber mounting bracket 150. In this case, vibration attenuation is performed corresponding to the moving distance of the mass part 120 .

In addition, when strong braking is applied, the first guide pin 131 connected to the push rod 140 moves along the guide pin guide hole 116, and the guide pin guide hole 116 is formed. The link mechanism 110 rotates clockwise, and the mass portion 120 rises along the guide groove 152 of the chamber mounting bracket 150. In this case, the maximum vibration attenuation is achieved in correspondence with the moving distance of the mass part 120 .

Therefore, the variable vibration damping structure of the pneumatic drum brake according to the present invention prevents excessive vibration from occurring at the end of the chamber mounting bracket connected to the anchor mounting bracket and causes excessive stress on the anchor mounting bracket, thereby extending the lifespan and safety of the brake. can provide an enhancing effect.

Those skilled in the art to which the present invention pertains will understand that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above are merely selected and presented to the most preferred embodiments to help those skilled in the art to understand among various possible embodiments, and the technical spirit of the present invention is not necessarily limited or limited only by the presented embodiments. No, and various changes, additions, and changes are possible within a range that does not deviate from the technical spirit of the present invention, as well as other equivalent embodiments. The scope of the present invention is indicated by the claims to be described later rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts thereof are included in the scope of the present invention. should be interpreted In addition, the terms or words used in this specification and claims are defined based on the principle that the inventor can appropriately define the concept of terms in order to explain his or her invention in the best way, It should not be construed as limited to meaning. In addition, the order of the components described in the above process does not necessarily have to be performed in a time-series order, and even if the order of performing each component and step is changed, if the gist of the present invention is satisfied, these processes may fall within the scope of the present invention. Of course there is.

100: variable vibration damping structure 110: link mechanism
114: coupling pin 116: guide pin guide hole
120: mass part 122: rod part
131: first guide pin 132: second guide pin
133: third guide pin 140: push rod
150: chamber mounting bracket 152: guide groove

Claims (10)

In the pneumatic drum brake,
a link mechanism interlocking with the first guide pin provided in the linearly moving push rod;
a mass portion moved along the chamber mounting bracket by the link mechanism;
a second guide pin connecting the link mechanism and the mass part; and
A third guide pin that connects the chamber mounting bracket and the link mechanism so that the mass portion moves along the chamber mounting bracket and serves as a rotational support point for the link mechanism during linear movement of the push rod;
In the link mechanism, two plate-shaped members are spaced apart from each other to transmit linear motion of the push rod to the mass part,
The third guide pin is connected to the chamber mounting bracket and the link mechanism together to serve as a support point for the link mechanism to rotate when the push rod moves linearly, so that the mass part moves,
A guide groove for guiding the reciprocating movement of the mass part is formed in the chamber mounting bracket,
Guide pin guide holes having a predetermined length with a width corresponding to the diameter of the first guide pin are bored inwardly of the two plate-shaped members of the link mechanism, and the first guide pin reciprocates along the guide pin guide hole to And to rotate the link mechanism around the third guide pin,
The guide groove is formed on one side of the chamber mounting bracket in a direction perpendicular to the ground,
The mass part reciprocates along the guide groove, and the mass part is located at the lower part of the guide groove of the chamber mounting bracket during non-braking and rises along the guide groove of the chamber mounting bracket during braking, thereby reducing vibration in response to the moving distance. A variable vibration damping structure of a pneumatic drum brake characterized by According to claim 1,
The variable vibration damping structure of the pneumatic drum brake, characterized in that the two plate-like members are connected by a coupling pin. According to claim 1,
The link mechanism is a variable vibration damping structure of a pneumatic drum brake, characterized in that for converting the linear motion of the push rod into rotational motion. delete According to claim 1,
The variable vibration damping structure of the pneumatic drum brake, characterized in that the second guide pin and the third guide pin are spaced apart from each other. delete According to claim 5,
The link mechanism is a variable vibration damping structure of a pneumatic drum brake, characterized in that the coupling holes coupled to the second guide pin and the third guide pin are perforated, respectively. According to claim 1,
The mass portion is a variable vibration damping structure of a pneumatic drum brake, characterized in that coupled to the rod portion connected to the second guide pin and the third guide pin. delete delete

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