KR102727661B1 - Check valve for integrated electric brake system - Google Patents

Abstract

A check valve for a brake system of the present invention is disclosed. According to one aspect of the present invention, an integrated electronic brake system check valve including a hydraulic block having a master cylinder installed and a plurality of channels and valves provided therein for controlling brake hydraulic pressure, and a hydraulic pressure generator coupled to the hydraulic block for generating hydraulic pressure in accordance with a pressure of a brake pedal and supplying the hydraulic pressure to a wheel cylinder, the integrated electronic brake system check valve comprising: a valve housing installed in a bore of the hydraulic block and having a through-hole formed therein to form an oil passage having an orifice therein; an opening/closing member provided in the valve housing for opening and closing the orifice; and a cap press-fitted into the through-hole to prevent oil in the valve housing from leaking to the outside; wherein the valve housing is detachably screw-coupled to the bore of the hydraulic block.

Description

Check valve for integrated electric brake system

The present invention relates to a check valve, and more specifically, to a check valve provided and used in an integrated electronic brake system.

Vehicles are equipped with a brake system for braking, and recently, various types of systems have been proposed to obtain stronger and more stable braking power. One example is the Intelligent Integrated Brake (IDB) system. The IDB system is proposed to generate stable and strong braking power by integrating a master booster and a vehicle stability control device (ESC).

For example, an electronic brake system is disclosed in European Patent No. EP 2520473 and Korean Patent Publication No. 10-2013-0092045. According to the disclosed documents, the electronic brake system includes a hydraulic pressure generator that outputs the operation of a brake pedal as an electric signal through a pedal displacement sensor to operate a motor and converts the rotational force of the motor into linear motion to generate braking hydraulic pressure, a hydraulic block having a plurality of valves installed to control the braking operation by receiving hydraulic pressure from the force generated by the hydraulic pressure generator, a pedal simulator that provides a reaction force to the pedal, and an electronic control unit that controls the motor and valves.

These electronic brake systems are designed to supply oil to each hydraulic chamber of the master cylinder and the hydraulic pressure generator or pedal simulator provided in the hydraulic block through a reservoir in which oil is stored. In addition, check valves are installed at appropriate times and locations in the oil path formed in the hydraulic block to control the flow of oil in one direction.

As is widely known, a check valve is configured to allow oil to flow in only one direction by having a valve seat formed within a valve housing and having an oil passage, a ball for opening and closing the oil passage, an elastic member for elastically supporting the ball, and a retainer for preventing the elastic member from coming off. This check valve is fixed to a bore formed in a hydraulic block by a press-fit and stacking process.

However, since the check valve is a purely mechanical structure that operates by hydraulic pressure, if it malfunctions, for example, if foreign substances become adhered to the oil passage of the valve seat or if the ball loses its function of opening and closing the oil passage due to buckling of the elastic member, the oil flow will not be smooth. In particular, if the check valve connected to the hydraulic pressure generating device that generates the hydraulic pressure malfunctions, there is a problem that the braking force intended by the driver will not be generated, which may cause a safety accident.

Accordingly, the check valve that has a problem must be replaced, but due to the nature of the IDB system in which components are assembled into a single hydraulic block, there is an inconvenience in that separate parts cannot be replaced and the entire system must be replaced, which increases replacement costs.

European Patent EP 2 520 473 A1 (Honda Motor Co., Ltd.) 2012. 11. 7. Republic of Korea Publication Patent No. 10-2013-0092045 (Mando Corporation) 2013. 08. 20.

A check valve for an integrated electronic brake system according to an embodiment of the present invention enables easy replacement of only a malfunctioning check valve.

According to one aspect of the present invention, there is provided an integrated electronic brake system check valve including a hydraulic block having a master cylinder installed and a plurality of channels and valves provided therein for controlling brake hydraulic pressure, and a hydraulic pressure generator coupled to the hydraulic block for generating hydraulic pressure in accordance with a pressure of a brake pedal and supplying the hydraulic pressure to a wheel cylinder, the integrated electronic brake system check valve comprising: a valve housing installed in a bore of the hydraulic block and having a through-hole formed therein to form an oil passage having an orifice therein; an opening/closing member provided in the valve housing for opening and closing the orifice; and a cap press-fitted into the through-hole to prevent oil in the valve housing from leaking to the outside; wherein the valve housing is detachably screw-coupled to the bore of the hydraulic block.

In addition, the valve housing may have a body portion having screw threads formed on an outer surface thereof to be screw-connected to the bore; and a head portion having a polygonal shape formed integrally with the body portion to be connected to an external tool.

In addition, the head portion further includes an external step portion, and the external step portion can be deformed under pressure to fix the cap that is press-fitted into the through hole.

Additionally, the through hole may have a first step portion where the cap is installed and a second step portion where the orifice is formed.

In addition, the cap may have a stopper portion positioned within the through hole to limit movement of the opening/closing member; and a plug portion extending radially outward from the stopper portion and press-fittingly connected to the first step portion.

The check valve for an integrated electronic brake system according to one embodiment of the present invention is easily attached and detached by being screwed into a bore of a hydraulic block. In addition, since the head of the valve housing is formed to have a polygonal shape so as to be coupled with a commercial tool, it can be easily attached and detached from the outside using, for example, a hex wrench or the like. Accordingly, since a single check valve can be replaced, there is an effect of reducing the replacement cost compared to replacing the entire existing brake system.

In addition, by replacing a defective check valve through a malfunction test of the check valve in a production line of an integrated electronic brake system in which a check valve according to one aspect of the present invention is assembled, not only can the cost be reduced, but also the reliability of the product can be improved.

The present invention will be specifically described with reference to the drawings below. However, since these drawings illustrate preferred embodiments of the present invention, the technical idea of the present invention should not be interpreted as being limited to the drawings.
FIG. 1 is an exploded perspective view showing a state in which a check valve for an integrated electronic brake system according to a preferred embodiment of the present invention is assembled to a hydraulic block.
Figure 2 is an assembled perspective view of Figure 1.
FIG. 3 is a cross-sectional view showing a check valve for an integrated electronic brake system according to a preferred embodiment of the present invention.
Figure 4 is a cross-sectional view showing a state in which a cap provided on the check valve illustrated in Figure 3 is fixed to a valve housing.
Figure 5 is a drawing showing the operating state of a check valve according to a preferred embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are presented to sufficiently convey the idea of the present invention to those skilled in the art to which the present invention pertains. The present invention is not limited to the embodiments presented herein and may be embodied in other forms. In order to clarify the present invention, the drawings may omit parts that are not related to the description, and may somewhat exaggerate the sizes of components to help understanding.

FIG. 1 is an exploded perspective view showing a state in which a check valve for an integrated electronic brake system according to a preferred embodiment of the present invention is assembled to a hydraulic block, FIG. 2 is an assembled perspective view of FIG. 1, and FIG. 3 is a cross-sectional view showing the check valve for the integrated electronic brake system.

Referring to FIGS. 1 to 3, a check valve (100) includes a valve housing (110) having an oil passage (113) formed therein, an opening/closing member (120) provided in the valve housing (110) to open/close the oil passage (113), and a cap (130) coupled to the valve housing (110) to prevent oil in the valve housing (110) from leaking to the outside. This check valve (100) is installed in a bore (11) formed in a hydraulic block (10) to prevent reverse flow of oil and control the oil to flow in only one direction.

Meanwhile, the check valve (100) according to one aspect of the present invention is applied to an integrated electronic brake system. The integrated electronic brake system is a known technology including a hydraulic block (10) in which a master cylinder is installed and a plurality of paths and valves for controlling the braking hydraulic pressure are provided inside, and a hydraulic pressure generating device (not shown) coupled to the hydraulic block (10) to generate hydraulic pressure according to the pressure of the brake pedal and supply the hydraulic pressure to the wheel cylinder, so a detailed description thereof will be omitted.

The valve housing (110) has an oil passage (113) formed inside by a through hole (112) through which the center is penetrated, and an orifice (113a) and an outlet (113b) are formed which communicate with the inlet passage (12) and the outlet passage (13) formed in the hydraulic block (10), respectively. At this time, the valve housing (110) is installed in the bore (11), and the orifice (113a) and the outlet (113b) are formed to correspond to the positions where the inlet passage (12) and the outlet passage (13) are formed. More specifically, the valve housing (110) has a body portion (111) having screw threads formed on the outer circumference so as to be screw-connected to the bore (11), and a head portion (115) formed integrally with the body portion (111).

The body part (111) has a cylindrical shape with an oil passage (113) formed inside by a through hole (112), and is screw-connected to the bore (11). Accordingly, screw threads are formed in the bore (11) so as to be screw-connected with screw threads formed on the outer surface of the body part (111). An orifice (113a) communicating with an inlet passage (12) is formed on the lower side of the body part (111), and an outlet (113b) communicating with an outlet passage (13) is formed on the periphery of the body part (111). At this time, in order to prepare for a case where the outlet (113b) and the outlet passage (13) are not in communication with each other and are misaligned due to the valve housing (110) being screw-connected to the bore (11), a predetermined space, i.e., an outlet passage, is formed in the bore (111) around where the outlet (113b) is located.

The head (115) is formed integrally with the body (111) and is formed to have a polygonal shape so as to be combined with an external tool (not shown). As shown, the head (115) has a hexagonal shape. Accordingly, the head (115) is combined with an external tool, such as a hexagon wrench, so that the valve housing (110) can be easily assembled or disassembled into the bore (11). Meanwhile, when the valve housing (110) is screw-coupled to the bore (111), the head (115) is installed so as to be spaced apart from the hydraulic block (10) by a certain distance. That is, it should be installed so that a certain space (S) is formed between the outer surface of the head (115) and the hydraulic block (10). This is to enable the hexagon wrench and the head (115) to be easily combined. In addition, an external step (114) is provided on the head (115). The above external step portion (114) is formed on the upper end surface of the head portion (115) in which the through hole (112) is formed. This external step portion (114) is used to secure a cap (130) installed in the valve housing (110), and will be described again below.

Meanwhile, the through hole (112) formed in the valve housing (110) has a first step portion (112a) and a second step portion (112b) that are stepped in the longitudinal direction. A cap (130) to be described later is installed in the first step portion (112a), and the second step portion (112b) has a reduced diameter to form an orifice (113a). At this time, the first step portion (112a) is formed in the head portion (115) of the valve housing (110), and the second step portion (112b) is formed in the body portion (111). In addition, the first step portion (112a) has the same diameter as the plug portion of the cap (130), and the second step portion (112b) has a tapered shape that is inclined toward the center so as to be closed by an opening/closing member (120) to be described later.

The opening/closing member (120) is provided to be movable within the valve housing (110) and serves to open/close the orifice (113a). That is, the opening/closing member (120) controls the flow of oil by opening/closing the orifice (113a). At this time, the opening/closing member (120) may be formed of a spherical ball, as illustrated. Here, it is obvious that the diameter of the ball (120) is larger than the diameter of the orifice (113a) and smaller than the diameter of the oil passage (113) in order to close the orifice (113a). This ball (120) closes the orifice (113a) by gravity and the pressure of the oil flowing in through the inflow passage (12), thereby opening the orifice (113a).

The cap (130) is press-fitted into the through hole (112) to prevent oil inside the valve housing (110) from leaking to the outside. More specifically, the cap (130) has a stopper part (132) positioned inside the through hole (112) and a plug part (134) formed integrally with the stopper part (132) and press-fitted into the through hole (112).

The stopper part (132) has a cylindrical shape with a predetermined length and is placed in the oil passage (113). This stopper part (132) is placed at a predetermined distance from the opening/closing member (120), thereby limiting the movement distance of the opening/closing member (120).

The plug portion (134) is formed to extend in an outer radial direction from the stopper portion (132). Accordingly, the plug portion (134) is seated on the first step portion (112a) and is press-fitted.

When the cap (130) is press-fitted into the valve housing (110), the cap (130) is fixed by the external step (114) so that it does not come off from the valve housing (110) due to hydraulic pressure. Referring to FIG. 4, when the cap (130) is press-fitted into the through hole (112) of the valve housing (110), the external step (114) is deformed by pressure using an assembly tool (not shown) so that it wraps around the upper edge of the plug (134) of the cap (130), thereby stably fixing the cap to the valve housing (110).

Then, the operating state of a check valve having the above structure will be briefly explained with reference to FIGS. 4 and 5.

First, as shown in Fig. 5, oil flows into the orifice (113a) of the valve housing (110) through the inflow path (12). At this time, the pressure of the flowing oil moves the opening/closing member (120) upward from the orifice (113a) to open the oil passage (113) of the valve housing (110). That is, as the orifice (113a) and the discharge port (113b) are connected to each other, the oil is discharged to the discharge path (13).

Next, when the oil pressure decreases or reverse flow occurs, as shown in Fig. 4, the opening/closing member (120) comes into contact with the second step (112b) by gravity or hydraulic pressure. This closes the orifice (113a).

As described above, the check valve (100) according to one aspect of the present invention is detachably screw-connected to the bore (11) of the hydraulic block (10), so that even if the check valve (100) malfunctions, only the check valve can be easily replaced and used, thereby reducing replacement costs.

As described above, although the present invention has been described by means of limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by those skilled in the art to which the present invention pertains within the scope of the technical idea of the present invention and the equivalent scope of the patent claims to be described below.

100 : Check valve 110 : Valve housing
111 : Body 115 : Head
120: Opening member 130: Cap

Claims (5)

A check valve for an integrated electronic brake system, comprising: a hydraulic block in which a master cylinder is installed and an inlet path, an outlet path, and a valve are provided inside for controlling the hydraulic pressure of the brake pedal; and a hydraulic pressure generating device coupled to the hydraulic block to generate hydraulic pressure according to the pressure of the brake pedal and supply the hydraulic pressure to the wheel cylinder.
A valve housing installed inside the bore of the above hydraulic block and having a through hole formed therein to form an oil passage having an orifice therein;
An opening/closing member that is movably provided inside the valve housing to open/close the orifice; and
A cap is included that is press-fitted into the above through hole to prevent oil inside the valve housing from leaking to the outside;
The above valve housing is detachably screwed into the bore of the hydraulic block, and an outlet is formed in a body portion having threads formed on the outer surface to be screwed into the bore.
The above bore
A check valve for an integrated electronic brake system, wherein a recessed path is formed on the inside to allow the discharge port and the discharge path to communicate with each other. In the first paragraph,
The above valve housing,
A check valve for an integrated electronic brake system, comprising a head portion having a polygonal shape formed integrally with the body portion and configured to be coupled with an external tool. In the second paragraph,
A check valve for an integrated electronic brake system, wherein the head part further comprises an external step part, and the external step part is deformed under pressure and fixes the cap which is press-fitted into the through hole. In the first paragraph,
A check valve for an integrated electronic brake system having a first step portion in which the cap is installed and a second step portion in which the orifice is formed, wherein the above through-hole is a first step portion in which the cap is installed and a second step portion in which the orifice is formed. In paragraph 4,
The above cap,
A stopper portion positioned within the above through hole to limit movement of the opening/closing member; and
A check valve for an integrated electronic brake system, comprising a plug portion that extends radially outward from the stopper portion and is press-fitted to the first step portion.

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