Brake booster of a vehicle

Abstract

Brake booster (1) comprising the following: a poppet valve body (10) configured to open a path for atmospheric pressure to be introduced into a sliding pressure chamber by means of an actuating rod (13) linked to a brake pedal; and a return spring structure (30) arranged on an outer side of the disc valve body (10) and configured to set an elastic force provided to the disc valve body (10) when an input is released from the brake pedal; wherein the return spring structure (30) comprises the following: a spring housing (31) which is coupled to the outside of the disc valve body (10) and has the actuating rod (13) movably formed therein; and a return spring (33) installed in the spring housing (31) to provide an elastic force to the outer surface of the disc valve body (10); wherein the return spring structure (30) further comprises a retaining device (35) which is arranged on an end section of the spring housing (31), and a coupling hole (31b) which is formed in a middle section thereof, so that the actuating rod (13) is inserted into and coupled to the holding device (35), and is configured to accommodate the return spring (33) on a surface thereof; wherein the holding device (35) comprises the following: a support element (37) having a plate shape with a storage groove (37a), which is configured to accommodate the return spring (33) in one of its surfaces; and a coupling element (39) which is formed such that it projects from one surface of the support element (37) in a drum shape; characterized in that the coupling element (39) has a hook section (39a) which is formed such that it projects inwards from an end section thereof; and the actuating rod (13) has a hook projection (13a) formed on one side thereof, so that the hook section (39a) is hooked in.

Description

Technical area

[0001] The present invention relates to a brake booster of a vehicle. State of the art

[0002] In general, a braking device (braking system) of a vehicle is a device configured to generate braking force for a running vehicle to prevent the vehicle from moving arbitrarily, and is operated by hydraulic pressure generated and supplied from a master cylinder, generally due to an operation of a brake pedal.

[0003] That is, a brake pedal stepped on by a driver to generate a braking force, a brake booster provided to amplify a pedal force of the brake pedal using a difference between a negative pressure (a vacuum pressure) and an atmospheric pressure generated by an engine, a master cylinder configured to convert the pedal force of the brake pedal into a hydraulic pressure, a brake main body provided to receive the hydraulic pressure from the master cylinder to generate a substantial braking force, and the like are mounted in the vehicle.

[0004] That is, the brake booster is a device configured to amplify an operating force of the brake pedal to operate the master cylinder, wherein two chambers including a constant pressure chamber, also called a vacuum chamber or constant pressure chamber, which forms a vacuum, and a sliding pressure chamber, also called a variable pressure chamber or working chamber, which is configured to introduce atmospheric air, are formed in the brake booster, and both the constant pressure chamber and the sliding pressure chamber initially maintain a vacuum.

[0005] Since the brake booster having the two chambers described above has a poppet valve opened by an operating rod linked to the brake pedal, atmospheric air can be introduced into the sliding pressure chamber when the brake pedal is depressed.

[0006] Since the poppet valve generally has a return spring that is compressed and stretched when it receives an input from the brake pedal therein, the poppet valve can return to its initial state using an elastic force of the return spring when the input from the brake pedal is released.

[0007] But a conventional return spring has a coupling structure that provides an elastic restoring force to return the poppet valve to an initial state, and thus it generates vibration by directly receiving an impact load applied to the brake booster when the brake pedal is suddenly depressed.

[0008] Since vibration generation of the return spring is inversely transmitted through the poppet valve and an operating rod to the brake pedal, thus causing a driver who steps on the brake pedal to feel vibrations of the brake booster, the vibration generation of the return spring causes difficulty in adjusting an elastic force in a limited space included in the poppet valve.

[0009] DE 25 26 391 A1 describes a servo motor with a working section having a working piston subjected to differential pressure and controlled by an input force, and a hydraulic delivery section having a delivery piston arrangement slidably arranged in a housing bore and coupled to the working piston.

[0010] DE 699 02 009 T2 describes a pneumatic brake servo motor which is actuated by a push rod which is movable within a hub between a rest position and an outermost actuating position, for each of which a check valve is closed and opened relative to a pressure source, wherein the check valve is separated from the source by a cleaning filter.

[0011] EP 0 220 098 A1 describes a vacuum brake booster having a power piston defining a first bore defined at one end by a reaction disc and in which a piston connected to an input push rod is slidably received.

[0012] DE 31 14 965 A1 describes a control device for the valve device of a brake booster, in which a hydraulic pressure exerted on a working piston is controlled by the control of the valve device in response to a movement of an actuating rod which is mechanically coupled to a brake pedal, the valve device having a valve tappet which is connected to the free end of the actuating rod. RevelationTechnical Problem

[0013] Based on the prior art, the object of the invention is to provide a brake booster configured to adjust an elastic force to satisfy an operating feeling required by a driver stepping on a brake pedal. Technical solution

[0014] The object is achieved according to the invention with a brake booster having the features of patent claim 1.

[0015] Advantageous further training results from the dependent subclaims. Beneficial effects

[0016] Since a brake booster according to an embodiment of the present invention has a return spring structure arranged on an outer side of a poppet valve body, an elastic force can be easily adjusted, and thus an operation feeling that a driver feels when stepping on a pedal can be adapted to an individual characteristic of the driver.

[0017] Furthermore, according to the embodiment of the present invention, the brake booster may have a holding device, and thus a return spring can be easily fixed. Description of the drawings Fig. 1 is a cross-sectional view illustrating a brake booster in accordance with an embodiment of the present invention. Fig. 2 is an exploded perspective cross-sectional view illustrating the brake booster in accordance with the embodiment of the present invention. Fig. 3 is a perspective cross-sectional view illustrating the brake booster in accordance with the embodiment of the present invention. Fig. 4 is a perspective view illustrating a holding device of the brake booster in accordance with the embodiment of the present invention. Fig. 5 is a perspective cross-sectional view illustrating a state in which the brake booster holding device according to the embodiment of the present invention is coupled to an operating rod. Embodiments of the invention

[0018] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which may allow one of ordinary skill in the art to easily practice the present invention. The present invention can be implemented in various forms and is not limited to the following embodiments. Components not related to the description have been omitted from the drawings in order to describe the present invention clearly and concisely, and the same reference numerals are used throughout the description for the same or similar components.

[0019] Fig. 1 is a cross-sectional view illustrating a brake booster in accordance with an embodiment of the present invention. Fig. 2 is an exploded perspective cross-sectional view illustrating the brake booster in accordance with the embodiment of the present invention. Fig. 3 is a perspective cross-sectional view illustrating the brake booster in accordance with the embodiment of the present invention.

[0020] As in Fig. 1, in the following description, it is determined that a direction from a retainer to a return spring is described as a forward direction, and it is determined that a direction from the return spring to the retainer is described as a reverse direction.

[0021] With reference to Fig. 1, a brake booster 1 according to an embodiment of the present invention includes a poppet valve body 10 and a return spring structure 30. In this case, the brake booster 1 may be divided into a constant pressure chamber or vacuum chamber mounted in a vehicle and forming a vacuum, and a sliding pressure chamber or working chamber configured to introduce atmospheric air. Furthermore, the brake booster 1 may amplify a pedal force of the brake pedal using a difference between a negative pressure (a vacuum pressure) and an atmospheric pressure generated by an engine when a driver steps on the brake pedal. Meanwhile, the brake booster 1 may include an electronic brake booster.

[0022] According to the embodiment of the present invention, the poppet valve body 10 can be opened and closed to introduce atmospheric air into the sliding pressure chamber or to prevent atmospheric air from entering the sliding pressure chamber. Furthermore, the poppet valve body 10 may include a valve housing 11, a valve element 15, and an actuating rod 13.

[0023] Accordingly, the poppet valve body 10 is opened by receiving a pressure from the operating rod 13 associated with an operation of the brake pedal to move, and as a result, it can introduce the atmospheric air into the sliding pressure chamber during the operation of the brake pedal.

[0024] According to the embodiment of the present invention, the operating rod 13 may be installed in an inner central portion of the valve housing 11 and linked to the brake pedal to transmit pedal force. In this case, the valve element 15 may be coupled to a front side of the operating rod 13. Furthermore, the operating rod 13 may be coupled to a return spring structure so as to be movable within the return spring structure 30. In this case, a hook projection 13a may be formed on one side of the operating rod 13, and it may be fixed to a hook portion 39a of a coupling member 39, which will be described below.

[0025] Meanwhile, the valve element 15 may be formed to slide in a longitudinal direction of the actuating rod in the valve housing 11 through the actuating rod 13. In this case, a fixing member 17 may be installed at a rear end portion of the valve housing to prevent the valve element 15 from breaking out of the valve housing 11.

[0026] According to the embodiment of the present invention, the fastening element 17 may be a circular spring steel such as a retaining ring. In this case, the fastening element 17 may be inserted into a groove formed in an end portion of the valve housing to fix the valve element 15 inserted into the valve housing, thus preventing the valve element 15 from breaking off.

[0027] Meanwhile, the brake booster 1 according to the embodiment of the present invention can easily adjust an elastic force by installing the return spring structure 30 on the outside of the valve poppet body 10, that is, by installing the return spring structure in a space other than a limited area inside the poppet valve body, and accordingly, an operation feeling that the driver feels when stepping on the pedal can be adjusted to an individual characteristic of the driver.

[0028] Fig. 4 is a perspective view illustrating a holding device of the brake booster in accordance with the embodiment of the present invention. Fig.5 is a perspective cross-sectional view illustrating a state in which the brake booster holding device according to the embodiment of the present invention is coupled to an operating rod.

[0029] Meanwhile, according to the embodiment of the present invention, the return spring structure 30 can be elastically transformed when the poppet valve body 10 receives an input from the brake pedal, and can apply an elastic restoring force to the poppet valve body when the input from the brake pedal is released. For this purpose, the return spring structure 30 may include a spring housing 31, a return spring 33, and a retainer 35.

[0030] According to the embodiment of the present invention, the spring housing 31 may be coupled to the rear end portion of the valve housing 11. Furthermore, the spring housing 31 may have a hollow portion so that the operating rod 13, the return spring 33, and the retainer 35 can be installed in the spring housing 31. A first coupling hole 31b may be formed in a central portion of the spring housing 31 so that the operating rod 13 can be inserted and coupled.

[0031] In this case, the spring housing 31 has a cylindrical shape, and a wrinkled portion configured to extend in a longitudinal direction may be formed on an outer side of the spring housing 31. Accordingly, the spring housing 31 can adjust flexibility to adjust the elastic force together with the return spring 33. Furthermore, the spring housing 31 may have a flow hole 31a formed in a rear end surface thereof. In this case, the atmospheric air in the spring housing 31 can flow through the flow hole 31a.

[0032] Meanwhile, in accordance with the embodiment of the present invention, the return spring 33 may have a coil spring shape and may apply an elastic restoring force to the valve element 15 when the input from the brake pedal is released.

[0033] According to the embodiment of the present invention, the retainer 35 may support the return spring to prevent the return spring 33 from breaking. In this case, the retainer 35 may include a support member 37 and the coupling member 39. Furthermore, a second coupling hole 35a may be formed in a central portion of the retainer 35 so that the operating rod 13 can be inserted and coupled.

[0034] According to the embodiment of the present invention, the support member 37 may have a disc shape. Furthermore, the support member 37 may have a housing groove 37a formed therein for housing the return spring 33 on a front surface thereof. In this case, a diameter of the housing groove 37a may be larger than or equal to a diameter of the return spring 33, and thus the return spring can be fixed in the housing groove 37a.

[0035] Meanwhile, a vent hole 37b configured to extend through the front surface and a rear surface of the support member 37 may be formed in the support member 37. In this case, the support member 37 can prevent noise generation due to the circulating of a non-uniform airflow through the vent hole 37b when the introduction of the non-uniform airflow occurs.

[0036] Furthermore, a projection 38 configured to protrude forward may be formed on an outer edge of the support member 37. The projection 38 serves to prevent separation of the return spring 33.

[0037] Furthermore, the coupling member 39 configured to protrude from the support member 37 may be formed on a front surface thereof. In this case, the coupling member 39 may be formed to extend forward from the second coupling hole 35a. Furthermore, the coupling member 39 may have a hook structure for being fixed to the hook projection 13a of the operating rod 13. In this case, the coupling member 39, coupled to the operating rod 13 by the hook projection 13a, may have excellent fixing force, thus preventing it from breaking off when mounted.

[0038] That is, the hook portion 39a configured to protrude in an inward direction may be formed at an end portion of the coupling member 39. In this case, the hook portion 39a may be formed to have different heights protruding in an inward direction from a front end to a rear end in order to have excellent fixing force with the hook projection 13a.

[0039] Furthermore, a slit 39b configured to extend in a longitudinal direction may be formed in the coupling member 39. In this case, the slit 39b may be formed in a plurality, and the plurality of slits 39b may be arranged to be spaced from each other by the same distance in a circumferential direction of the coupling member 39. In this case, the plurality of slits 39b may be formed to extend from a front end portion of the coupling member 39 to a rear end portion of the coupling member 39.

[0040] Accordingly, the brake booster 1 according to the embodiment of the present invention may have the plurality of slots 39b for easy insertion upon insertion into the operating rod 13 having a diameter larger than an inner diameter of the coupling member 39, and thus easy operation can be ensured.

[0041] Although an embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment described in the specification, and although those skilled in the art may devise other embodiments by adding, changing, or removing components within the scope of the same spirit of the present invention, such embodiments and the above embodiments are also included within the scope of the spirit of the present invention. Reference symbol 1 brake booster 11 Valve housing 13a Hook projection 17 Fastening element 31 Spring housing 31b first coupling hole 35 Holding device 37 Support element 37b Ventilation hole 39 Coupling element 39b slot 10 poppet valve bodies 13 Operating rod 15 Valve element 30 Return spring structure 31a Flow hole 33 Return spring 35a second coupling hole 37a Accommodation groove 38 lead 39a Hook section

Claims

[1] Brake booster (1) comprising: a poppet valve body (10) configured to open a path for atmospheric pressure to be introduced into a sliding pressure chamber through an operating rod (13) linked to a brake pedal; and a return spring structure (30) disposed on an outer side of the poppet valve body (10) and configured to adjust an elastic force provided to the poppet valve body (10) when an input from the brake pedal is released; wherein the return spring structure (30) comprises: a spring housing (31) coupled to the outside of the poppet valve body (10) and having the actuating rod (13) movably formed therein; and a return spring (33) installed in the spring housing (31) for providing an elastic force to the outer surface of the poppet valve body (10); wherein the return spring structure (30) further comprises a holding device (35) arranged at an end portion of the spring housing (31), having a coupling hole (31b) formed in a central portion thereof, such that the actuating rod (13) is inserted into and coupled to the holding device (35) and is configured to accommodate the return spring (33) on a surface thereof; wherein the holding device (35) comprises: a support member (37) having a plate shape with a housing groove (37a), which is configured to accommodate the return spring (33) in a surface thereof; and a coupling member (39) formed to protrude from one surface of the support member (37) in a drum shape; characterized by , that the coupling member (39) has a hook portion (39a) formed to protrude inward from one end portion thereof; and the operating rod (13) has a hook projection (13a) formed on one side thereof so that the hook portion (39a) is hooked. [2] Brake booster (1) according to claim 1, wherein a diameter of the accommodation groove (37a) is larger than or equal to a diameter of the return spring (33). [3] The brake booster (1) according to claim 1, wherein the coupling member (39) has a slit (39b) formed to extend in a longitudinal direction, the slit (39b) being formed in the plurality, and the plurality of slits (39b) being formed to be spaced apart from each other along a circumferential direction of the coupling member (39). [4] The brake booster (1) according to claim 1, wherein a vent hole (37b) is formed in one side of the support member (37) to prevent noise from being generated by irregular fluid introduction. [5] A brake booster (1) according to claim 1, wherein the spring housing (31) has a wrinkled portion formed to be flexible in an outer surface thereof. [6] Brake booster (1) according to claim 1, wherein a flow hole (31a) is formed in a surface of the spring housing (31) so that a fluid is introduced.

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