Pulsation reduction device of a hydraulic piston pump

Abstract

The present invention relates to a pulsation reduction device of a hydraulic piston pump, comprising: a block housing having one end connected to the first hydraulic circuit and the other end connected to the second hydraulic circuit; a damper embedded in the block housing, absorbing pressure resulting from a working fluid being introduced into the first hydraulic circuit, assisting the pressure increase of the second hydraulic circuit, and allowing shape deformation;and viscosity damping units embedded in the block housing, arranged between the first hydraulic circuit and the damper and between the second hydraulic circuit and the damper, and reducing the viscosity of the working fluid introduced from the first and second hydraulic circuits, thereby reducing pressure pulsation and stably performing shock absorption and pressure increase at the same time, with a relatively simple configuration.;

Description

CROSS REFERENCE TO RELATED APPLICATIONThis application claims priority under 35 U.S.C. § 119(a) to and the benefit of Korean Patent Application No. 10-2014-0044923, filed on Apr. 15, 2014, which is hereby incorporated by reference for all purposes as if fully set forth herein.BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a pulsation reduction device of a hydraulic piston pump, and more particularly to a pulsation reduction device of a hydraulic piston pump that reduces pressure pulsation and in which shock mitigation and pressure increase are stable and performed at the same time with a relatively simple configuration.2. Description of the Prior ArtA vehicle posture control device (e.g., electronic stability control (ESC)) corresponds to a device for detecting slipping by a vehicle itself even without a separate control of a driver, thereby controlling the pressure and engine output applied to front wheels and rear wheels of the vehicle.In general, in such an ESC, when a working fluid is introduced into two hydraulic circuits, that is, a front side circuit of the vehicle and a rear side circuit of the vehicle, in order to increase a pressure, pulsation of the working fluid is forcibly generated due to an operation of a pump.Such pulsation causes a change in a signal collected by a pressure sensor, thereby adversely affecting boost performance.Although a large number of existing technologies are known and have been developed to reduce such pressure pulsation, most of these technologies have a large number of components and are complex, and as a result, an increase in production cost is unavoidable.Furthermore, the existing pressure pulsation reduction apparatuses have a problem in that noise is generated due to interference between components.Further, a rubber damper provided in the existing pressure pulsation reduction device may be deformed according to torsion due to a pressure difference between the two hydraulic circuits, may be caused to crack or crack or be damaged.SUMMARY OF THE INVENTIONThe present invention is designed to improve the above-mentioned problem, and an aspect of the present invention is to provide a pulsation reduction device that reduces pressure pulsation and in which shock mitigation and pressure increase are stable and performed at the same time with a relatively simple configuration.To achieve the above-described aspect, the present invention provides a pulsation reduction device of a hydraulic piston pump, the pulsation reduction device including: a first hydraulic circuit that connects a master cylinder for forming a control hydraulic pressure and wheel brakes provided in a pair of wheels to each other according to an operation of a brake pedal to regulate fluid pressure transmission; a second hydraulic circuit that connects a master cylinder for forming a control hydraulic pressure and wheel brakes provided in a pair of wheels to each other according to an operation of a brake pedal to regulate fluid pressure transmission; a block case in which one end is connected to the first hydraulic circuit and the other end is connected to the second hydraulic circuit; a damper embedded in the block case absorbs pressure resulting from a working fluid being introduced into the first hydraulic circuit, promoting pressure increase of the second hydraulic circuit, and allowing shape deformation; and viscosity damping units embedded in the block case are disposed between the first hydraulic circuit and the damper and between the second hydraulic circuit and the damper, and reducing the viscosity of the working fluid introduced from the first and second hydraulic circuits.The present invention having the above-mentioned configuration can achieve the following effects.First, the present invention can mitigate shock resulting from the pressure of the working fluid introduced through a first hydraulic circuit and at the same time stably increase a pressure of a second hydraulic circuit, with a relatively simple configuration in which a damper and a viscosity damping unit are provided inside a block case disposed between a first hydraulic circuit and a second hydraulic circuit, thereby reducing pulsation and consequently improving the ride quality.Specifically, the present invention attenuates a shock resulting from an inflow pressure of the working fluid sequentially in an order of first and second ports, the viscosity damping unit, and the damper of the block case, thereby improving a ride quality by a degressive shock damping effect.Further, the present invention can disperse and absorb a pressure of the working fluid directly applied to a damper by the viscosity damping unit to some extent, so that durability of the damper is improved, thereby prolonging the useful life while preventing deformation, breakage, and damage resulting from torsion.BRIEF DESCRIPTION OF THE DRAWINGSThe above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a conceptual view illustrating an overall structure of a hydraulic circuit system in which a pulsation reduction device of a hydraulic piston pump according to an embodiment of the present invention is mounted; FIG. 2 is a sectional conceptual view illustrating an overall structure of a pulsation reduction device of a hydraulic piston pump according to an embodiment of the present invention; and FIG. 3 is a perspective cutaway view illustrating an internal structure of a pulsation reduction device of a hydraulic piston pump according to an embodiment of the present invention.DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTSEMBODIMENTSHereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. It should be understood that when it is described in the following description that one component is "connected", "coupled", or "joined" to another component, a third component may be "connected", "coupled", and "joined" between the first and second components, although the first component may be directly connected, coupled, or joined to the second component.Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.FIG. 1 is a conceptual view illustrating an overall structure of a hydraulic circuit system in which a pulsation reduction device of a hydraulic piston pump according to an embodiment of the present invention is mounted.Further, FIG. 2 is a sectional conceptual view illustrating an overall structure of a pulsation reduction device of a hydraulic piston pump according to an embodiment of the present invention, and FIG. 3 is a perspective cutaway view illustrating an internal structure of a pulsation reduction device of a hydraulic piston pump according to an embodiment of the present invention.It can be appreciated that the present invention has a structure including a first hydraulic circuit 1, a second hydraulic circuit 2, a block case 10, a damper 20, and a viscous damping unit 30, as illustrated.The first hydraulic circuit 1 connects a master cylinder 4 that forms a control hydraulic pressure and wheel brakes 6 aand 6 bprovided in a pair of wheels 5 aand 5 b,respectively, to each other according to an operation of a brake pedal 3, thereby regulating fluid pressure transmission.The second hydraulic circuit 2 connects the master cylinder 4 forming a control hydraulic pressure and wheel brakes 6 cand 6 dprovided in a pair of wheels 5 cand 5 d,respectively, to each other according to the operation of the brake pedal 3, thereby regulating the fluid pressure transmission.In the block case 10, one end is connected to the first hydraulic circuit 1 and the other end is connected to the second hydraulic circuit 2.The damper 20 is embedded in the block case, absorbs the pressure resulting from a working fluid being introduced through the first hydraulic circuit 1, assists a pressure increase of the second hydraulic circuit 2, and allows a shape deformation.The viscous damping units 30 are embedded in the block case 10, are disposed between the first hydraulic circuit 1 and the damper 20, and between the second hydraulic circuit 2 and the damper 20, and reduce the viscosity of the working fluid introduced from the first and second hydraulic circuits 1 and 2.As a result, the present invention can alleviate shock resulting from the inflow pressure of the working fluid in an order of the damper 20 and the viscosity damping unit 30 through the block case 20, thereby reducing pulsation and improving riding comfort.In the present invention, the above-described embodiment can be applied, and various embodiments described below can also be applied.It can be appreciated that the block case 10 houses the damper 20 and the viscosity damping unit 30 as described above, and corresponds to a structure including a case body 13 and first and second openings 11 and 12 as illustrated.The housing body 13 has an approximately cylindrical inner space 14 in which the damper 20 and the viscosity damping unit 30 are embedded.The first port 11 extends through one end of the housing body 13 to communicate with the internal space 14, and is connected to the first hydraulic circuit 1.The first port 12 extends through the other end of the housing body 13 to communicate with the internal space 14, and is connected to the second hydraulic circuit 2.As a result, a shock resulting from the pressure of the working fluid introduced into the internal space 14 through the first hydraulic circuit 1 or the second hydraulic circuit 2 is alleviated primarily.Meanwhile, it can be recognized that the damper 20 attenuates shock resulting from the pressure of the working fluid introduced from the first hydraulic circuit 1 or the second hydraulic circuit 2 as described above, and that with reference to FIGS. 2 and 3 as described above, it is a structure including a damper body 23 and first and second damping grooves 21 and 22.The damper body 23 is a cylindrical member embedded in the block case 10, and is preferably made of an elastic material to alleviate an impact resulting from the introduction of the working fluid.The first damping groove 21 is recessed in a surface of the damper body 23 facing the first hydraulic circuit 1, and allows a shape deformation corresponding to an additional pressing caused by allowing the first damping groove 21 to receive the working fluid introduced through the first hydraulic circuit 1 and to be pressed toward the second hydraulic circuit 2, that is, toward the second opening 12, the cut surface thereof having an arc shape.The second damping groove 22 is recessed in the other surface of the damper body 23 facing the second hydraulic circuit 2, and allows a shape deformation corresponding to an additional pressing caused by allowing the second damping groove 22 to receive the working fluid introduced through the second hydraulic circuit 2 and to be pressed toward the first hydraulic circuit 1, that is, toward the first opening 11, the cut surface thereof having an arc shape.Further, the first damping groove 21 and the second damping groove 22 face the viscosity damping unit 30, which will be described later.Meanwhile, a cylindrical corner part of the damper body 23 is rounded to uniformly and smoothly distribute an impact of the working fluid introduced from the first opening 11 or the second opening 12 to an opposite side.Further, it is preferable that the damper body 23 further includes a shock absorbing annular groove 24 that is recessed in an annular shape along the side surface of the damper body 23 and connects edges of the one surface and the other surface to each other such that the first damping groove 21 and the second damping groove 22 directly receive the working fluid and perform a shock absorbing effect, thereby preventing defects such as torsion or uneven distribution when the shape deformation is performed and assist in the shape restoration.Meanwhile, as described above, it can be recognized that the viscosity damping unit 30 reduces the viscosity of the working fluid introduced from the first and second hydraulic circuits 1 and 2, and specifically is a structure including a first damping plate 30 aand a second damping plate 30 bas illustrated in FIGS. 2 and 3 with respect to FIG. 4.First, the first damper plate 30 ais embedded in the block case 10 so as to be in contact with one surface of the damper 20, faces the first hydraulic circuit 1, forms a first through hole 33 formed at a central portion thereof to communicate with the first opening 11, allows the working fluid to flow to a central portion of the one surface of the damper 20, and allows the working fluid to flow through the entire surface.The second damper plate 30 bis embedded in the block case 10 so as to be in contact with the other surface of the damper 20, face the second hydraulic circuit 2, form a second through hole 34 formed at a central portion thereof to communicate with the second opening 12, allow the working fluid to flow to a central portion of the other surface of the damper 20, and allow the working fluid to flow through the entire surface.Here, the diameters of the first through hole 33 and the second through hole 34 are equal to or larger than the diameters of the first opening 11 and the second opening 12, thereby easily implementing shock absorbing performance of the working fluid.More specifically, the first cushion plate 30 ais a structure including the first through hole 33 and a first cushion mesh (or cushion mesh) 35 on a first plate body 31.The first plate body 31 is a circular plate-shaped member of which edges are in contact with and fixed to the inner circumferential surface of the cylindrical inner space 14.The first through hole 33 is a member that is formed through the center of the first plate body 31 and allows the working fluid to flow to the central portion of the one surface of the damper 20.The first damping grille 35 is formed by a plurality of members formed throughout the entire surface of the first plate body 31 to reduce the viscosity of the working fluid.That is, the first attenuation grating 35 has a plurality of rectangular through slits 39 arranged along a plurality of virtual concentric circles C formed from an edge of the first through hole 33 to an edge of the first plate body 31.[Description of Reference Numerals]1 First hydraulic circuit 2 Second hydraulic circuit 3 Brake pedal 4 Master cylinder 5 a, 5 b A pair of wheels provided on one side of the vehicle 5 c, 5 d A pair of wheels provided on the other side of the vehicle 6 a, 6 b, 6 c, 6 d Wheel brakes 10 Block housing 11 First opening 12 Second opening 13 Housing body 14 Inner space 20 Damper 21 First damping groove 22 Second damping groove 23 Damper body 24 Shock-damping annular groove 30 Viscosity damping unit 30 aFirst damping plate 30 bSecond damping plate 31 First plate body 32 Second plate body 33 First through hole 34 Second through hole 35 First damping mesh 36 Second damping mesh 39 Continuous slit

Claims

A pulsation reduction device of a hydraulic piston pump, comprising: a first hydraulic circuit (1) that connects a master cylinder (4) for forming a control hydraulic pressure and wheel brakes (6a, 6b) provided in a pair of wheels (5a, 5b) to each other according to an operation of a brake pedal (3) so as to regulate fluid pressure transmission; a second hydraulic circuit (2) that connects a master cylinder (4) for forming a control hydraulic pressure and wheel brakes (6c, 6d) provided in a pair of wheels (5c, 5d) to each other according to the operation of the brake pedal (3) so as to regulate fluid pressure transmission; a block case (10) in which one end is connected to the first hydraulic circuit (1) and the other end is connected to the second hydraulic circuit (2); a damper (20) embedded in the block case (10) absorbs a pressure resulting from a working fluid being introduced into the first hydraulic circuit (1), promoting pressure increase of the second hydraulic circuit (2) and allowing shape deformation; and viscosity damping units (30) embedded in the block case (10) are disposed between the first hydraulic circuit (1) and the damper (20) and between the second hydraulic circuit (2) and the damper (20), and reducing the viscosity of the working fluid introduced from the first and second hydraulic circuits (1, 2).The pulsation reduction device of a hydraulic piston pump according to claim 1, wherein the block housing (10) includes: a housing body (13) having an inner space (14) formed therein and in which the damper (20) and the viscosity damping units (30) are embedded; a first opening (11) formed by one end of the housing body (13) to communicate with the inner space (14) and connected to the first hydraulic circuit (1); and a second opening (12) formed by the other end of the housing body (13) to communicate with the inner space (14) and connected to the second hydraulic circuit (2), the viscosity damping units (30) allowing a flow of the working fluid introduced from the first opening (11) and the second opening (12).The pulsation reduction device of a hydraulic piston pump according to claim 1, wherein the viscosity damping units (30) include: a first damping plate (30a) embedded in the block case (10) so as to be in contact with one surface of the damper (20), facing the first hydraulic circuit (1), allowing the working fluid to flow to a central portion of the one surface of the damper (20), and allowing the working fluid to flow through an entire surface; and a second damping plate (30b) embedded in the block case (10) so as to be in contact with the other surface of the damper (20), facing the second hydraulic circuit (2), allowing the working fluid to flow to a central portion of the other surface of the damper (20), and allowing the working fluid to flow through the entire surface.The pulsation reduction device of a hydraulic piston pump according to claim 3, wherein the first and second damping plates (30a, 30b) each include: a circular plate-shaped first and second plate body (31, 32) edges of which contact and are fixed to an inner circumferential surface of the cylindrical inner space (14) of the block housing (10); first and second through holes (33, 34) formed through central portions of the first and second plate bodies (31, 32) and allowing the working fluid to flow to the central portion of the one surface of the damper (20); and a plurality of first and second members formed through the entire surface of the first and second plate bodies (31, 32) and reducing the viscosity of the working fluid.The pulsation reduction device of a hydraulic piston pump according to claim 1, wherein the damper (20) includes: a damper body (23) embedded in the block case (10); and first and second damping grooves (21, 22) formed in one surface and the other surface of the damper body (23) to allow shape deformation.The pulsation reduction device of a hydraulic piston pump according to claim 5, wherein the damper body (23) is embedded in the block case (10), formed in a cylindrical shape, and made of an elastic material to alleviate an impact resulting from the introduction of the working fluid.The pulsation reduction device of a hydraulic piston pump according to claim 5, wherein the first and second damping grooves (21, 22) are recessed in the one surface and the other surface of the damper body (23) and face the viscosity damping units (30), and cut surfaces of the first and second damping grooves (21, 22) have arc shapes.The pulsation reduction device of a hydraulic piston pump according to claim 5, wherein the damper body (23) includes a shock absorbing annular groove (24) that is recessed in an annular shape along a side surface of the damper body (23) and connects edges of the one surface and the other surface to each other.

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