Piston Pump for Brake System

Abstract

A piston pump including a separable piston part for a brake is disclosed. According to one embodiment of the present disclosure, a piston pump is provided comprising: a piston portion configured to reciprocate within a piston housing by driving a motor cam; a sleeve portion formed to surround at least a portion of the piston portion and configured to store brake oil in a receiving space formed therein; and a check valve portion disposed facing the sleeve portion and configured to discharge brake oil to the outside of the sleeve portion when the pressure of the brake oil stored in the receiving space of the sleeve portion increases, wherein the piston portion comprises a first piston; a second piston; and a spring cap.

Description

Technology Field

[0001] The present disclosure relates to a piston pump for a brake system. Background Technology

[0002] The content described in this section merely provides background information regarding the present disclosure and does not constitute prior art.

[0003] FIG. 1 is a cross-sectional view schematically illustrating the structure of a piston pump for a conventional brake system.

[0004] Referring to FIG. 1, a conventional piston pump (1') includes a motor cam (10) configured to perform cam movement by driving a motor (not shown) and a piston unit (20) configured to perform reciprocating linear movement inside a piston housing (12).

[0005] The conventional piston part (20) includes a piston body (22); a cap coupling portion (24) in which at least a portion is coupled to a spring cap (30); a step unit (26) having an outer diameter larger than that of the cap coupling portion (24) and functioning as a stopper by restricting the movement of the spring cap (30); and a piston flange (28).

[0006] As the piston part (20) reciprocates, the piston body (22) comes into contact with the low pressure sealing (40). At this time, in order to ensure smooth reciprocating motion of the piston part (20), it is desirable to lower the coefficient of friction on the outer surface of the piston body (22). To this end, when manufacturing the piston part (20), the manufacturing process includes a polishing process.

[0007] Meanwhile, since the piston part (20) has a complex shape that connects the cap coupling part (24), the step part (26), and the piston flange (28), the complexity and difficulty of the polishing process increase. As a result, there is a problem that the defect rate increases when manufacturing the piston part (20).

[0008] In addition, during the reciprocating motion of the piston part (20), the part that actually rubs against the low-pressure sealing (40) is limited, but the entire piston body (22) undergoes a polishing process. Therefore, there is a problem that the manufacturing efficiency is lowered when manufacturing the piston pump (1') due to the unnecessary polishing process.

[0009] In addition, since the piston part (20) includes a stepped part (26) and a piston flange (28), the shape of the piston part (20) becomes complex, and consequently, there is a problem that the manufacturing cost increases. The problem to be solved

[0010] Accordingly, the main purpose of the present disclosure is to provide a piston pump capable of reducing manufacturing costs and lowering defect rates by eliminating the unnecessary grinding process.

[0011] In addition, the main purpose of the present disclosure is to provide a piston pump with high manufacturing efficiency.

[0012] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0013] According to one embodiment of the present disclosure, a piston pump is provided comprising: a piston unit configured to reciprocate within a piston housing by driving a motor cam; a sleeve unit formed to surround at least a portion of the piston unit and configured to store brake oil in a receiving space formed therein; and a check valve unit disposed facing the sleeve unit and configured to discharge brake oil to the outside of the sleeve unit when the pressure of the brake oil stored in the receiving space of the sleeve unit increases, wherein the piston unit comprises: a first piston formed to reciprocate with one end in contact with the motor cam; a second piston formed to apply pressure to the brake oil stored in the receiving space of the sleeve unit, with one end coupled to the other end of the first piston and coupled to the reciprocating motion of the first piston; and a spring cap coupled to the other end of the second piston and configured to accommodate an inlet spring therein.

[0014] According to another embodiment of the present disclosure, a piston pump is provided comprising: a piston portion configured to reciprocate within a piston housing by driving a motor cam; a sleeve portion formed to surround at least a portion of the piston portion and configured to store brake oil in a receiving space formed therein; and a check valve portion disposed facing the sleeve portion and configured to discharge brake oil to the outside of the sleeve portion when the pressure of the brake oil stored in the receiving space of the sleeve portion increases, wherein the piston portion comprises: a first piston formed to reciprocate with one end in contact with the motor cam; a second piston formed to apply pressure to the brake oil stored in the receiving space of the sleeve portion in conjunction with the reciprocating motion of the first piston, wherein the other end of the first piston is press-fitted and coupled to one end of the piston; and a spring cap formed to accommodate an inlet spring inside and coupled to the other end of the second piston. Effects of the invention

[0015] As described above, according to the present embodiment, the piston part according to the present disclosure is formed as an assembled piston, thereby simplifying the polishing process and having the effect of lowering the defect rate. In addition, since the piston part is formed with a simple structure, there is an effect of lowering manufacturing costs.

[0016] In addition, eliminating unnecessary polishing processes and adopting a piston part with a simple structure has the effect of reducing manufacturing costs. Brief explanation of the drawing

[0017] FIG. 1 is a cross-sectional view schematically illustrating the structure of a piston pump for a conventional brake system. FIG. 2 is a cross-sectional view schematically illustrating the structure of a piston pump for a brake system according to one embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing a disassembled state of a piston part according to one embodiment of the present disclosure. FIG. 4 is a cross-sectional view illustrating the state in which brake oil is supplied to the receiving space of a sleeve portion according to one embodiment of the present disclosure. FIG. 5 is a cross-sectional view illustrating a state in which brake oil stored in the receiving space of a sleeve portion according to one embodiment of the present disclosure is discharged to the outside of the sleeve portion. FIG. 6 is a cross-sectional view schematically illustrating the structure of a piston pump for a brake system according to another embodiment of the present disclosure. FIG. 7 is a perspective view of a piston portion according to another embodiment of the present disclosure. FIG. 8 is a cross-sectional view of a piston portion according to another embodiment of the present disclosure. Specific details for implementing the invention

[0018] Some embodiments of the present disclosure are described in detail below with reference to the exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present disclosure, if it is determined that a detailed description of related known components or functions could obscure the essence of the present disclosure, such detailed description is omitted.

[0019] In describing the components of the embodiments according to the present disclosure, symbols such as first, second, i), ii), a), b), etc., may be used. These symbols are intended only to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the symbols. When a part in the specification is described as 'comprising' or 'having' a component, this means that, unless explicitly stated otherwise, it does not exclude other components but may include additional components.

[0020] In addition, it should be noted that the size, shape, and travel distance of each component of the piston pump (1 and 6) described in FIGS. 2 to 8 of the present disclosure may be expressed in a somewhat exaggerated or distorted manner for the sake of clarity and convenience of explanation.

[0021] FIG. 2 is a cross-sectional view schematically illustrating the structure of a piston pump for a brake system according to one embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing a disassembled state of a piston part according to one embodiment of the present disclosure. With reference to FIG. 2 and FIG. 3, the detailed structure of a piston pump (1) for a brake system according to one embodiment of the present disclosure will be described.

[0022] Referring to FIGS. 2 and 3, a piston pump (1) according to one embodiment of the present disclosure comprises all or part of a motor cam (10), a piston housing (12), a piston unit (100), a sleeve unit (200), a check valve unit (300), and a filter (400).

[0023] The motor cam (10) is assembled on the output shaft of a motor (not shown) and rotates and performs cam motion when the motor operates. Due to the cam motion of the motor cam (10), the piston part (100) reciprocates in the longitudinal direction inside the piston housing (12). The piston housing (12) is fixed to the vehicle body, and a space is formed inside for assembling each component of the piston pump (1).

[0024] The piston portion (100) includes all or part of a first piston (110), a second piston (120), a spring cap (130), an inlet spring (140), an inlet ball (150), and a first sealing (160).

[0025] One end of the first piston (110) contacts the motor cam (10) and is formed to reciprocate in the longitudinal direction inside the piston housing (12) by the driving of the motor cam (10). The first piston (110) includes all or part of a sliding unit (112), a first coupling unit (114), and an inserting hole (116).

[0026] At least a portion of the sliding part (112) is surrounded by a second sealing (520), a backup ring (540), and a guide ring (560). At this time, friction is generated by the second sealing (520), the backup ring (540), and the guide ring (560). Meanwhile, in the piston part (100) according to the present disclosure, since only the first piston (110) where actual friction occurs can be polished, there is an effect of lowering the defect rate during the manufacture of the piston pump (1).

[0027] The first connecting part (114) is formed at the other end of the first piston (110) and is coupled to the second piston (120). A passage through which brake oil can flow is formed inside the first connecting part (114).

[0028] The insertion hole (116) is formed between the sliding part (112) and the first fastening part (114). At least a portion of the brake oil introduced from the inlet line (14) passes through the insertion hole (116) and flows into the internal path of the first fastening part (114).

[0029] The second piston (120) is coupled to the first connecting part (114) and is linked to the movement of the first piston (110). The second piston (120) is configured to transmit hydraulic pressure generated by the reciprocating linear movement of the first piston (110) to the brake oil stored in the receiving space (220). When the second piston (120) moves in the direction of pressurizing the brake oil (left side in FIG. 2), the brake oil stored inside the receiving space (220) moves to the outlet line (16).

[0030] The second piston (120) includes all or part of a piston head unit (122), a step unit (124), and a second coupling unit (126).

[0031] The piston head portion (122) is formed in a roughly hollow column shape, and at least a portion of the inlet ball (150) can be inserted into the inner side of the piston head portion (122). At least a portion of the piston head portion (122) has an outer diameter of the first diameter (D1).

[0032] The stepped portion (124) is formed at the end of the piston head portion (122) and can serve as a stopper for the spring cap (130). At least a portion of the stepped portion (124) has a second diameter (D2) with an outer diameter larger than the first diameter (D1).

[0033] The second fastening portion (126) is formed on the inner side of the stepped portion (124) and is fastened to the first fastening portion (114). The first fastening portion (114) and the second fastening portion (126) can preferably be press-fitted. For example, the first fastening portion (114) can be coupled to the second fastening portion (126) by a press fit. However, the present disclosure is not necessarily limited thereto, and the first fastening portion (114) and the second fastening portion (126) can be screw-coupled using threads formed on each of the first fastening portion (114) and the second fastening portion (126).

[0034] In the present disclosure, the first fastening part (114) is depicted as a male portion and the second fastening part (126) is depicted as a female portion, but is not necessarily limited thereto. For example, the first fastening part (114) may be a female portion and the second fastening part (126) may be a male portion.

[0035] The second piston (120) is formed with a first diameter (D1) and a second diameter (D2), so the structure is simple, and thus the manufacturing process can be simplified.

[0036] The spring cap (130) is coupled to the piston head portion (122) and is configured to accommodate an inlet spring (140) and an inlet ball (150) inside. Even when the second piston (120) reciprocates, the inlet spring (140) and the inlet ball (150) may not be displaced from their initial positions inside the spring cap (130).

[0037] The spring cap (130) includes all or part of a piston coupling unit (132), a cap head unit (134), a slope unit (136), and a flange unit (138).

[0038] The piston coupling portion (132) is configured to surround at least a portion of the piston head portion (122) and to be coupled with the piston head portion (122). The inner diameter of the piston coupling portion (132) may be equal to the first diameter (D1) or slightly smaller than the first diameter (D1). As a result, the piston coupling portion (132) and the piston head portion (122) can be coupled by press fitting. However, the spring cap (130) and the second piston (120) according to the present disclosure do not necessarily need to be press-fitted, and screw coupling, etc., is possible.

[0039] The cap head portion (134) is configured to accommodate an inlet spring (140) in a space provided inside. The cap head portion (134) is configured to be fluidly connected to the inside and outside. For example, the cap head portion may be configured in the form of a cage. At least a portion of the cap head portion (134) has a third diameter (D3) in which the inner diameter is smaller than the first diameter (D1).

[0040] The inclined portion (136) is positioned between the piston coupling portion (132) and the cap head portion (134), and its inner diameter decreases in the direction from the piston coupling portion (132) toward the cap head portion (134). When the second piston (120) moves in the direction of pressurizing the brake oil, it comes into contact with the inner circumference of the inclined portion (136), and the second piston (120) is no longer able to pressurize the inlet spring (140) and the inlet ball (150). That is, the inclined portion (136) can perform the function of a stopper for the second piston (120).

[0041] A flange portion (138) is formed at the end of the piston coupling portion (132). A first seal (160) may be disposed between the flange portion (138) and the stepped portion (124). The first seal (160) can prevent brake oil flowing in from the inlet passage (14) from flowing into the receiving space (220).

[0042] One side of the inlet spring (140) contacts the inlet ball (150), and the other side is fixed to the ceiling of the spring cap (130). The inlet spring (140) elastically supports the inlet ball (150) by pressing the inlet ball (150) in the direction in which the motor cam (10) is installed.

[0043] The inlet ball (150) pressurizes the second piston (120) in the direction where the motor cam (10) is installed by the inlet spring (140). The inlet ball (150) performs the function of a check valve by restricting the flow of brake oil discharged from the piston head portion (122).

[0044] The sleeve portion (200) is formed to surround at least a portion of the piston portion (100). The sleeve portion (200) includes all or part of an accommodation space (220), a return spring (240), and a discharge hole (260).

[0045] The receiving space (220) is formed inside the sleeve portion (200) and is formed to store brake oil. When the piston portion (100) moves by the motor cam (10) in a direction that pressurizes the brake oil stored in the receiving space (220), the receiving space (220) can function as a high-pressure chamber.

[0046] The return spring (240) is placed in the receiving space (220), with one end in contact with the spring cap (130) and the other end fixed to the inner ceiling of the sleeve portion (200). The return spring (240) elastically supports the spring cap (130) in the direction in which the motor cam (10) is installed. The return spring (240) provides an elastic force that presses the piston portion (100) in the direction in which the motor cam (10) is installed when the piston portion (100) returns to its initial position after being moved toward the check valve portion (300) by the motor cam (10).

[0047] A discharge hole (260) is formed on one side of the sleeve portion (200), and brake oil stored in the receiving space (220) can be discharged to the outside of the sleeve portion (200) by passing through the discharge hole (260).

[0048] The check valve section (300) is positioned to face one side of the sleeve section (200). The check valve section (300) is formed so that when the pressure of the brake oil stored in the receiving space (220) rises, the brake oil is discharged to the outside of the sleeve section (200). At this time, the check valve section (300) can be formed in various shapes within the technical concept of the brake oil rising and being discharged to the outside of the sleeve section (200). The check valve section (300) according to the present disclosure is equipped with an outlet spring (320) and an outlet ball (340).

[0049] The outlet spring (320) and the outlet ball (340) are positioned between the check valve section (300) and the sleeve section (200). The outlet spring (320) elastically supports the outlet ball (340) in the direction in which the motor cam (10) is installed. The outlet ball (340) is spherical in shape and is positioned to face the discharge hole (260). The outlet ball (340) controls the opening and closing of the outlet passage (16).

[0050] The filter (400) is formed to surround at least a portion of the piston portion (100). When brake oil flows from the inlet passage (14) toward the insertion hole (116), the brake oil passes through the filter (400). As it passes through the filter (400), foreign substances contained in the brake oil can be filtered.

[0051] In addition, the piston pump (1) according to the present disclosure may further include a second sealing (520), a backup ring (540), and a guide ring (560).

[0052] The second seal (520) is positioned between the piston housing (12) and the sliding part (112) and can block the flow of brake oil moving along the outside of the piston part (100).

[0053] The backup ring (540) is positioned adjacent to the second sealing (520) and supports the second sealing (520) when the second sealing (520) is subjected to pressure.

[0054] The guide ring (560) is positioned adjacent to the backup ring (540) and guides the movement of the piston part (100) so that linear movement is possible during the reciprocating movement of the piston part (100).

[0055] The operating state of a piston pump (1) according to one embodiment of the present disclosure is described in detail below.

[0056] FIG. 4 is a cross-sectional view illustrating the state in which brake oil is supplied to the receiving space of a sleeve portion according to one embodiment of the present disclosure.

[0057] The small arrow shown in FIG. 4 indicates the direction of flow of the brake oil, and the large arrow indicates the direction of movement of the piston part (100). Referring to FIG. 4, the motor rotates and the eccentric motor cam (10) rotates in one direction (the arrow indicated by the curve in FIG. 4). Due to the rotation of the motor cam (10), the first piston (110) and the second piston (120) move in the direction where the motor cam (10) is installed (to the right in FIG. 4). At this time, the pressure of the brake oil in the receiving space (220) of the sleeve part (200) decreases. As a result, the brake oil passes sequentially through the inlet oil passage (14), the insertion hole (116), and the piston head part (122). As the first piston (110) and the second piston (120) move in the direction where the motor cam (10) is installed, the inlet ball (150) and the second piston (120) are separated. The brake oil that has moved into the internal space of the piston head (122) passes through the spaced-apart space between the inlet ball (150) and the second piston (120), and sequentially flows through the spring cap (130) and the receiving space (220).

[0058] FIG. 5 is a cross-sectional view illustrating a state in which brake oil stored in the receiving space of a sleeve portion according to one embodiment of the present disclosure is discharged to the outside of the sleeve portion.

[0059] The small arrow shown in FIG. 5 indicates the direction of flow of the brake oil, and the large arrow indicates the direction of movement of the piston part (100). Referring to FIG. 5, the piston part (100) moves toward the check valve part (300) due to the rotation of the motor cam (10). Due to the forward movement of the piston part (100), the brake oil stored in the receiving space (220) of the sleeve part (200) is compressed. As a result, the pressure acting on the outlet ball (340) increases, and the outlet spring (320) is compressed. As the outlet ball (340) moves away from the discharge hole (260), the sleeve part (200) and the outlet ball (340) are separated, and a space is formed. Through the formed space, the brake oil is discharged and moves to the outlet oil passage (16). The brake oil that passes through the outlet oil passage (16) moves between the piston housing (12) and the sleeve part (200).

[0060] FIG. 6 is a cross-sectional view schematically illustrating the structure of a piston pump for a brake system according to another embodiment of the present disclosure.

[0061] Referring to FIG. 6, the piston part (600) of the piston pump (6) according to another embodiment includes a first piston (610), a second piston (620), and a spring cap (630).

[0062] A first piston (610) according to another embodiment of the present disclosure includes a sliding portion (612) and a first fastening portion (614).

[0063] One end of the sliding part (612) contacts the motor cam (10), and due to the rotational movement of the motor cam (10), it reciprocates in the longitudinal direction.

[0064] The first fastening portion (614) is formed to extend from the other end of the sliding portion (612) in a direction that presses the interior of the sleeve portion (200). At least a portion of the first fastening portion (614) is configured to be pressed into one end of the second piston (620). The fastening relationship between the first piston (610) and the second piston (620) will be explained in detail below.

[0065] Since the shape and technical features of the second piston (620) and spring cap (630) according to another embodiment of the present disclosure are identical or similar to those of the second piston (120) and spring cap (130) according to one embodiment, a detailed description thereof is replaced by the description of one embodiment.

[0066] FIG. 7(a) is an exploded perspective view of a portion of a piston part according to another embodiment of the present disclosure. FIG. 7(b) is an assembled perspective view of a portion of a piston part according to another embodiment of the present disclosure. FIG. 8(a) is a longitudinal cross-sectional view of a portion of the piston part of FIG. 7(b) cut along Ⅷa-Ⅷa'. FIG. 8(b) is a longitudinal cross-sectional view of a portion of the piston part of FIG. 7(b) cut along Ⅷb-Ⅷb'.

[0067] Referring to FIGS. 7 and 8, one end of the first piston (610) can be punched to allow brake oil to flow. At this time, at least a portion of the punched end is connected to the second piston (620) as shown in FIG. 7 (b). Meanwhile, the second piston (620) according to another embodiment of the present disclosure is punched in a direction perpendicular to the longitudinal direction and does not need to have a separate flow path formed parallel to the longitudinal direction. As a result, the manufacturing procedure is simplified and the defect rate is reduced during manufacturing.

[0068] Meanwhile, as shown in FIG. 8(b), at least a portion of the first piston (610) according to another embodiment of the present disclosure is pressed into the second piston (620). Meanwhile, the combination of the first piston (610) and the second piston (620) shown in FIG. 6 can be understood as the cross-section shown in FIG. 8(a).

[0070] The above description is merely an illustrative explanation of the technical concept of the present embodiment, and a person skilled in the art to which the present embodiment belongs would be able to make various modifications and variations within the scope of the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain, not limit, the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment. Explanation of the symbols

[0071] 1': Conventional piston pump 10: Motor cam 12: Piston housing 20: Piston part 30: Spring cap 40: Low pressure seal 1, 6, 7: Piston pump 14: Inlet passage 16: Outlet Euro 100, 600: Piston part 110, 610: 1st piston 120, 620: 2nd piston 130, 630: Spring cap 140: Inlet spring 150: Inlet ball 160: 1st ceiling 200: Sleeve section 300: Check valve section 400: Filter

Claims

Claim 1 A piston unit configured to reciprocate within a piston housing by the actuation of a motor cam; a sleeve unit formed to surround at least a portion of the piston unit and configured to store brake oil in a receiving space formed inside; and a check valve unit disposed facing the sleeve unit and configured to discharge brake oil to the outside of the sleeve unit when the pressure of the brake oil stored in the receiving space of the sleeve unit increases, wherein the piston unit comprises: a first piston formed to reciprocate with one end in contact with the motor cam; and a second piston formed to apply pressure to the brake oil stored in the receiving space of the sleeve unit, with one end coupled to the other end of the first piston and linked to the reciprocating motion of the first piston. The apparatus comprises a spring cap coupled to the other end of the second piston and formed to accommodate an inlet spring inside, wherein the second piston comprises: a piston head unit having at least a portion of its outer diameter having a first diameter; and a step unit having at least a portion of its outer diameter having a second diameter larger than the first diameter; and the spring cap comprises: a piston coupling unit coupled to at least a portion of the piston head unit; a housing head unit configured to accommodate the inlet spring and configured to have internal and external fluid communication; and a slope unit disposed between the piston coupling unit and the housing head unit, formed such that the inner diameter decreases in the direction from the piston coupling unit toward the housing head unit.A piston pump comprising a flange unit formed at the end of the piston coupling portion, wherein the piston portion further comprises a first sealing disposed between the flange unit and the stepped portion, and wherein the flange unit is integrally formed with the piston coupling portion to prevent brake oil from flowing from the outside of the sleeve portion through the first sealing into the receiving space. Claim 2 delete Claim 3 delete Claim 4 A piston pump according to claim 1, characterized in that at least a portion of the inner diameter of the cap head is a third diameter smaller than the first diameter. Claim 5 delete Claim 6 delete Claim 7 A piston pump according to claim 1, characterized in that the piston head portion and the piston coupling portion are press-fitted and joined. Claim 8 A piston pump according to claim 1, wherein the piston portion comprises an inlet ball disposed between the second piston and the spring cap and pressed in a direction toward the second piston by the inlet spring. Claim 9 A piston pump according to claim 1, wherein the first piston comprises a first coupling unit coupled to at least a portion of the second piston, and the second piston comprises a second coupling unit formed to surround the first coupling unit, wherein the first coupling unit and the second coupling unit are press-fitted. Claim 10 A piston pump according to claim 1, further comprising: a second sealing disposed between the piston housing and the first piston; a backup ring disposed between the piston housing and the first piston and formed to support the first piston; and a guide ring disposed between the piston housing and the first piston and formed to guide the reciprocating motion of the first piston. Claim 11 delete Claim 12 A piston pump according to claim 1, characterized in that one end of the first piston is punched in a direction perpendicular to the longitudinal axis so that brake oil can flow.

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