KR101114494B1 - The Master Cylinder for Vehicles - Google Patents

Abstract

The present invention relates to a retainer for supporting a return spring for returning a piston of a vehicle master cylinder, and for coupling the retainer to the piston by a simpler structure.

The configuration of the present invention for achieving this object has a cylinder body having a supply chamber for supply of oil and a bore formed therein, at least one piston provided to reciprocate in the bore, and in front of the piston A master cylinder comprising a return spring for providing a restoring force to a piston, and a retainer for supporting the return spring, wherein the piston includes an extension portion whose outer circumference extends forwardly so that a recess is formed therein; An engaging portion bent a predetermined length into the piston is formed on the end side of the portion, and the retainer has a cylindrical shape in which the front side is opened. The separation is prevented by the negative.

Description

     The Master Cylinder for Vehicles

1 is a cross-sectional view schematically showing the structure of a master cylinder according to the present invention.

Figure 2 is an enlarged cross-sectional view of the coupling state of the return spring, retainer and piston shown in FIG.

3 is a perspective view showing a retainer according to the present invention.

             * Description of the symbols for the main parts of the drawings *

   1 ... Master Cylinder 2 ... Bore

   20 ... the first piston 22 ... the locking part

   23 ... concave 26 ... extend

   30 ... 2nd piston 50 ... 1st return spring

   60 ... 2nd return spring 70 ... 1st retainer

   71 Opening 72 Outward flange

   73 ... blanking 74 ... hollow

   76 oil hole

     The present invention relates to a vehicle master cylinder, and more particularly to a retainer for supporting a return spring for returning the piston of the vehicle master cylinder.

     In general, the hydraulic brake system of a vehicle pressurizes oil supplied from a reservoir to generate hydraulic pressure, and delivers hydraulic pressure to each wheel through the brake hydraulic line, and pushes the brake shoes or discs inside each wheel to be in close contact with the inner surface of the brake drum. A drum-type hydraulic brake that generates a braking force by friction, in which two brake shoes come into contact with the inner surface of the brake drum to generate a braking torque (braking force) due to frictional force in a brake drum inside the wheel, which is integrally rotated with the wheel. Instead of the drum, a disk-type hydraulic brake is used to generate a braking torque by strongly pressing the wheel and the disk-shaped brake disk rotated on both sides.

     In addition, the braking device requires a master cylinder for generating hydraulic pressure for the braking force of the vehicle, and the master cylinder includes various components for generating hydraulic pressure. Among these components include a return spring for returning the piston after the piston has advanced and a retainer for supporting the return spring.

     In Korean Patent Laid-Open Publication No. 2004-0091429, a first piston is installed in a booster side and connected to a push rod in a cylinder body forming an exterior of a master cylinder, and a first spring is installed in front of the first piston. And a second piston, and a second spring. A first return spring is installed between the first piston and the second piston, and a first retainer supporting the first return spring is provided on the front side of the first return spring, and the position facing the first retainer, that is, the first return spring is provided. A second retainer attached to the front portion of the first piston head is provided.

     In addition, the first retainer and the second retainer are coupled by a stum consisting of a head part inserted into the first retainer hole and a screw part inserted into and fixed to a screw groove formed in the front side of the first piston head through the second retainer hole. do.

However, the conventional master cylinder configured as described above has a problem in that a number of parts such as a first retainer, a second retainer, and a stem are required to support the spring, thereby increasing the number of parts and increasing the production cost.

     In addition, Korean Patent Laid-Open Publication No. 2002-89566 discloses a method of riveting a first retainer directly to a piston without using a stud and a second retainer in a manner of supporting a spring of the master cylinder. It is.

     However, such a method of riveting and coupling has a problem in that the assembly time increases and productivity decreases. In particular, the retainer is made of a steel material is not easily deformable there is a problem in the design for the function to fasten the spring has a lot of problems.

The present invention is to solve the above problems, to provide a master cylinder of a brake system for a vehicle brake system to improve the productivity by reducing the number of parts, as well as the assembly time by simplifying the structure for fastening the spring of the master cylinder. The purpose is to.

The vehicle master cylinder according to the present invention for achieving this object, the cylinder body having a supply chamber for supply of oil and a bore formed therein, at least one piston provided to reciprocate in the bore, In the master cylinder including a return spring is provided in front of the piston to provide a restoring force to the piston, and a retainer for supporting the return spring, the piston has an extended portion with an outer circumference extending forward to form a recess therein And an engaging portion bent a predetermined length into the piston at the end side of the extension portion, and the retainer has a cylindrical shape with an open front face, and the opening side is inserted into the concave portion and coupled to the outer periphery of the opening. Is formed is characterized in that the separation is prevented by the locking portion .

 In addition, the outward flange portion is characterized in that a plurality of blanking portions are formed in the circumferential direction at regular intervals to facilitate insertion when the retainer is pressed into the piston.

 In addition, the retainer is characterized in that made of a plastic material excellent in elastic deformation.

 In addition, the retainer is characterized in that made of a plastic material excellent in elastic deformation.

 In addition, the inner rear wall of the piston is characterized in that the protrusion is formed to protrude a predetermined length forward to fix the return spring.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to Figure 1, the master cylinder (1) according to the present invention is equipped with a reservoir (not shown) for supplying oil to the outer upper side and a plurality of sealing grooves (3) are formed in the inner bore (2) sealing groove The cylinder body 10 is provided with the sealing members in the (3), the first piston 20 for sliding the inside of the bore 2 in accordance with the operation of the driver's brake pedal (not shown), and the second piston ( 30, the first hydraulic chamber 21, which is a space in which hydraulic pressure is formed between the first piston 20 and the second piston 30, and the inner end walls of the second piston 30 and the bore 2; And a second hydraulic chamber 31, which is a space in which the hydraulic pressure is formed between (4).

The cylinder body 10 is formed in the upper portion of the inlet port (5,6) for supplying oil into the bore (2) from the reservoir (not shown), and the oil supplied from the inlet port (5,6) bore ( 2) circumferential direction to the inner surface of the bore 2 in communication with the supply holes 7 and 8 radially penetrating from the lower part of the inlet ports 5 and 6 to guide the inside, and the supply holes 7 and 8 And a bore 2 in which the pistons 20 and 30 are slidably provided to deliver oil to the wheel brakes (not shown).

The supply chambers 9a and 9b are grooved in the circumferential direction on the inner surface of the bore 2 so that the oil supplied from the supply holes 7 and 8 is stored in the supply chambers 9a and 9b so that the hydraulic chambers 21 and 31 are provided. ) So that oil can be injected quickly. In addition, outlet ports 21a and 31a are formed at one side of the hydraulic chambers 21 and 31 so as to communicate with a hydraulic circuit (not shown) to deliver oil to a wheel brake (not shown).

The bore 2 is provided with first sealing members 40 and 41 in front and rear between the first piston 20 and the bore 2, and in the front and rear between the second piston 30 and the bore 2, Sealing members 42 and 43 are provided. These sealing members 40, 41, 42, 43 are provided in the sealing groove (3) formed in the bore (2) is provided to prevent the departure even by the reciprocating movement of the piston (20, 30).

At this time, the first front sealing member 40 performs sealing between the first hydraulic chamber 21 and the first supply chamber 9a, and the second front sealing member 42 is the second hydraulic chamber 31 and the second. Sealing between the supply chambers 9b is performed.

In addition, between the first piston 20 and the second piston 30, a first return spring 50 for returning the first piston 20 and a first retainer supporting the first return spring 50 ( 70 is provided and supports the second return spring 60 and the second return spring 60 for returning the second piston 30 between the second piston 30 and the distal inner wall 4 of the bore. The second retainer 80 is installed.

The master cylinder 1 configured as described above has the first piston 20 and the second piston 30 moving forward when the push rod (not shown) pushes the first piston 20 of the master cylinder 1. Hydraulic pressure is generated in the hydraulic chamber 21 and the second hydraulic chamber 31. The hydraulic pressure is supplied to the wheel cylinders (not shown) on the front wheel and the rear wheel side through the first and second outlet ports 21a and 31a to operate the brakes (not shown).

In addition, when the pressure of the master cylinder (1) is released, it is returned by the first and second return springs 50 and 60 provided in the push rod (not shown), the first piston 20 and the second piston 30, respectively. do. That is, when the first piston 20 and the second piston 30 are in close contact with each other, when the first piston 20 and the second piston 30 are in operation, they are returned by the restoring force of the first and second return springs 50 and 60 provided, respectively. .

The first retainer 70 according to the present invention will be described with reference to FIGS. 2 and 3, wherein the first retainer 70 has a cylindrical shape having one side open and a hollow inside thereof, the outer periphery of the opening 71. When the first retainer 70 is engaged with the first piston 20 to be described later, the first retainer 70 may be caught by the engaging portion 22 formed at the tip of the first piston 20 to prevent the first piston 20 from being separated from the first piston 20. An outward flange portion 72 protruding radially outward is formed.

At the circumference of the outward flange portion 72, a plurality of blanking portions 73 are obtained by punching or the like at regular intervals in the circumferential direction, and the first retainer 70 is press-fitted into the first piston 20. The outward flange portion 72 is easily elastically deformed so that it can be easily coupled to the first piston 20.

The body portion 75 forming the hollow portion 74 of the first retainer 70 is provided with an oil hole 76 through which oil can pass, so that the hydraulic pressure in the hollow portion 74 when the first piston 20 is moved forward. And the hydraulic pressure in the first hydraulic chamber 21 to be in balance with each other.

Although the material of the first retainer 70 may be used as a material of metal, it is preferable to use a synthetic resin made of plastic so that elastic deformation easily occurs.

In addition, the first piston 20 to which the first retainer 70 is coupled is connected to a booster (not shown) that increases the force applied to the brake pedal of the vehicle at one end of the first piston 20 and the other end thereof. An extension portion 26 is formed in the outer circumference extending in the direction of the second piston 30 to form the recess 23 therein.

 An oil stored in the first supply chamber 9a is introduced into the bore 2 by allowing the first piston 20 to communicate with the first supply chamber 9a according to the sliding movement. The cutoff hole 27 is formed to be able to. In addition, the front end portion of the extension portion 26 is formed with a locking portion 22 to prevent the first retainer 70 inserted into the first piston 20 from being bent into the first piston 20. . Here, the inner diameter of the locking portion 22 is formed to be substantially the same as the outer diameter of the first retainer 70 so that the first retainer 70 is recessed in the first piston 20 when the first piston 20 is advanced. 23) to be able to enter.

Moreover, the protrusion part 25 which protruded the predetermined length toward the recessed part 23 is formed in the rear wall 24 inside the recessed part 23 so that the 1st return spring 50 may be provided.

The first return spring 50 in the master cylinder 1 configured as described above is installed between the inner rear wall of the hollow portion 74 of the first retainer 70 and the inner rear wall 924 of the first piston recess 23. After the first piston 20 is advanced, the first piston 20 is returned.

In addition, the coupling structure of the second piston 30 and the second retainer 80 is formed in the same manner as the coupling structure of the first piston 20 and the first retainer 70 to perform the same function as described above. Replace it.

Hereinafter, the operation and effects by the configuration of the present embodiment will be described.

First, referring to the structure of assembling the first retainer 70 supporting the first return spring 50 to the first piston 20, one end of the first return spring 50 may be a protrusion of the first piston 20. The outward flange portion 72 of the first retainer 70 to the engaging portion 22 of the first piston 20, with the other end fixed to the inner wall of the first retainer 70. When a force is applied, the outward flange portion 72 of the first retainer 70 made of an elastic material is elastically deformed by the plurality of blanking portions 73 formed at predetermined intervals on the outward flange portion 72 so that the first piston 20 ), The outward flange portion 72 is restored to its original state by the elastic force, and the outward flange portion 72 of the first retainer 70 is caught by the first piston 20. Engaged in the portion 22, the first retainer 70 is prevented from being separated from the first piston (20).
Meanwhile, the process of assembling the second retainer 80 to the second piston 30 is the same as the method of assembling the first retainer 70 to the first piston 20, and thus, detailed description thereof will be omitted.

    The master cylinder 1 configured as described above advances the first piston 20 of the master cylinder 1 through the booster device (not shown) when the driver presses a brake pedal (not shown) during braking. When the oil is compressed in the sealed first hydraulic chamber 21, the hollow portion 74 of the first retainer 70, and the concave portion 23 of the first piston 20, the second piston 30 is interlocked. The oil is compressed in the second hydraulic chamber 31 by advancing. At this time, the first return spring 50 and the second return spring 60 are provided in front of the first piston 20 and the second piston 30, respectively. 60, the first piston 20 and the second piston 30 is compressed when moving forward and release the force applied to the brake pedal, the piston (20, 30) by the elastic force of the return spring (50, 60) Is restored.

As described in detail above, the retainer structure of the master cylinder according to the present invention is not a conventional coupling method or a method of riveting the retainer to the piston, but the retainer is composed of an elastic material inside the piston Since the assembly is simple, the assembly time is shortened and the number of parts is reduced, thereby reducing the production cost.

Claims (5)

A cylinder body 10 having supply chambers 9a and 9b for supplying oil and having a bore 2 formed therein, and first and second pistons provided to be slidable inside the bore 2. 20) 30, a first hydraulic chamber 21 which is a space in which hydraulic pressure is generated by the first piston 20, and a second hydraulic chamber 31 in which hydraulic pressure is generated by the second piston 30. ) And between the first piston 20 and the second piston 30, and between the second piston 30 and the distal inner wall 4 of the bore 2, respectively, the first and second pistons. (20) (30) between the return spring (50, 60) to provide a restoring force, and the first piston 20 and the second piston (30) to support the respective return spring (50, 60) and In the master cylinder (1) comprising retainers (70, 80) provided between the second piston (30) and the inner end wall of the bore (4), Each of the first and second pistons 20 and 30 has an extended portion 26 whose outer circumference extends forwardly so that a recess 23 is formed therein, and an end portion of each of the extended portions 26 The engaging portion 22 bent a predetermined length into the piston (20, 30) is formed, The retainers 70 and 80 have a cylindrical body portion 75 having an open front surface, and an opening 71 side is inserted into the recess 23 to be coupled to the outer periphery of the opening 71. The flange unit 72 is formed, the vehicle master cylinder, characterized in that the separation is prevented by the locking portion (22). The method of claim 1, The outward flange portion 72 is provided with a plurality of blanking portions 73 at regular intervals in the circumferential direction to facilitate insertion of the retainers 70 and 80 into the respective pistons 20 and 30. Vehicle master cylinder, characterized in that. The method of claim 1, In the body portion 75 of each of the retainers 70 and 80, the hydraulic pressure in the hollow portion 74 formed therein and the hydraulic pressure in the first hydraulic chamber 21 and the second hydraulic chamber 31 are balanced with each other. Vehicle master cylinder, characterized in that the oil hole 76 is formed so that the oil can pass. The method according to any one of claims 1 to 3, The retainer (70, 80) is a vehicle master cylinder, characterized in that made of a plastic material excellent in elastic deformation. The method of claim 1, A vehicle master cylinder, characterized in that the inner rear wall (24) of each of the piston (20, 30) is formed with a projection (25) protruding a predetermined length forward to fix one end of each return spring (50, 60).

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