JP4821492B2 - Piston pump - Google Patents

Description

  The present invention relates to a piston pump, for example, a piston pump that can be employed as a hydraulic pump of a vehicle brake device.

This type of piston pump is disclosed in, for example, Patent Document 1 below, and includes a pump housing having an inlet and a discharge port and an inner hole communicating with the suction port and the discharge port. A piston that is assembled in the inner hole to form a pump chamber and is reciprocated in the axial direction, and an inflow passage that is provided in the piston and communicates the suction port with the pump chamber. A suction valve that opens when the volume of the pump chamber increases and closes when the volume of the pump chamber decreases, and a discharge valve that intervenes in an outflow passage that communicates the discharge port with the pump chamber and opens when the volume of the pump chamber decreases. The piston flows back and forth in the axial direction to increase or decrease the volume of the pump chamber, so that the liquid flows from the suction port toward the discharge port. It is configured so that.
Special table 2003-500610 gazette

  In the above-described conventional piston pump, the suction valve includes a valve hole (communicating with the suction port) provided in the piston, a valve seat (formed at the end of the valve hole on the pump chamber side), and a piston. A cylindrical retainer assembled in the retainer, a valve body that is assembled in the retainer and can be seated on and separated from the valve seat portion, and the valve body is interposed between the valve body and the retainer. A spring that biases the valve seat portion is provided.

  In such a conventional piston pump, the valve hole and the valve seat portion of the intake valve are formed in the piston. Therefore, the intake valve cannot be configured unless a retainer, a valve body and a spring are assembled to the piston. For this reason, the suction valve cannot be configured independently of the piston, and there is room for improvement in the assembly of the suction valve. Therefore, the present invention makes it possible to make a sub-assembly of the suction valve separately from the piston, to improve the assembling property of the suction valve, and to ensure good assembling property in the suction valve. The problem is to secure the retention (make the components of the intake valve easy to assemble and hard to come off).

  The present invention also includes a pump housing having an inlet and an outlet and an inner hole communicating with the inlet and outlet, and a pump chamber that is assembled to the inner hole of the pump housing to form a shaft. A piston that increases or decreases the volume of the pump chamber by being reciprocated in the direction, and an inflow passage that is provided in the piston and communicates the suction port and the pump chamber, and opens when the volume of the pump chamber increases. A suction valve that closes when the pressure decreases, and a discharge valve that is interposed in an outflow passage that connects the discharge port and the pump chamber and closes when the volume of the pump chamber decreases, and closes when the volume increases, and the piston reciprocates in the axial direction. In the piston pump configured so that the liquid flows from the suction port toward the discharge port by being moved to increase or decrease the volume of the pump chamber, The suction valve includes a valve hole communicating with the suction port, a valve seat portion formed at a pump chamber side end portion of the valve hole, a valve body holding portion and a spring integrally formed continuously with the valve seat portion A retainer having a retainer and integrally assembled to the piston; and a valve body that is housed and retained in the valve body retainer of the retainer and that can be seated and separated from the valve seat; A spring that is housed and held in the spring holding portion of the retainer and urges the valve body toward the valve seat portion; and the valve body holding portion and the spring holding portion of the retainer are separated from the valve seat portion. It is comprised by the six columnar bodies extended in an axial direction, and these columnar bodies are divided into two symmetrically with respect to the virtual plane containing an axial centerline, and each of the three divided columnar bodies is divided into two. The tip is joined together and divided in two Each virtual triangle formed by connecting the base portions of the three columnar bodies is an isosceles triangle having a base parallel to the virtual plane and an obtuse angled vertex away from the virtual plane from the base. There is a feature in being.

  In this piston pump, the retainer assembled integrally with the piston has a valve hole and a valve seat portion of the intake valve, and has a valve body holding portion and a spring holding portion that are integrally formed continuously with the valve seat portion. Then, the valve body holding portion accommodates and holds the valve body that can be seated and separated from the valve seat portion, and the spring holding portion accommodates and holds the spring that biases the valve body toward the valve seat portion. For this reason, it is possible to construct the intake valve separately from the piston by assembling the valve body and the spring to the retainer and to make a sub-assembly, and it is possible to improve the assembly of the intake valve. is there.

  Further, in the retainer which is a constituent member of the suction valve, the combined body of three columnar bodies in which the respective tip portions are integrally coupled is combined with each other in the above-described virtual plane. The rigidity in the direction perpendicular to (the direction in which the combined body is expanded when the valve body and the spring are assembled into the retainer valve body holding part and the spring holding part) can be increased, but the root parts of the three columnar bodies are connected. Since each virtual triangle formed by the above is an isosceles triangle having the above-mentioned obtuse angle vertex, it is possible to prevent the rigidity in the direction orthogonal to the above-described virtual plane from being excessively increased. Therefore, it is possible to secure good assembling property of the valve body and the spring to the retainer and to secure good holding property (assembly reliability) of the valve body and the spring assembled to the retainer.

  In carrying out the present invention, the two columnar bodies extending in the axial direction from the base end portion of the isosceles triangle may be formed so as to approach each other sequentially toward the tip end portion. In this case, as compared to the case where the two columnar bodies extending in the axial direction from the base end portion of the isosceles triangle are parallel to each other, the direction along the above-described virtual plane (in the direction in which the combined body is expanded). It is possible to increase the rigidity in a direction perpendicular to the retainer, and when the valve body and the spring are incorporated into the retainer body and the spring holder of the retainer, the combined body moves in the direction along the imaginary plane described above. It is possible to suppress this, stabilize the direction in which the combined body is expanded, and improve the assembly of the valve body and the spring to the retainer.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a piston pump according to the present invention. In this piston pump, a pump housing 10 is constituted by a housing main body 11, a cylinder member 12 and a cap 13 assembled to the housing main body 11. The housing body 11 has a suction port 11a and a discharge port 11b, and has a stepped inner hole 11c communicating with the suction port 11a and the discharge port 11b, and the stepped inner hole 11c has a small diameter inner hole 11c1. The piston 21, the suction valve Vs, and the piston return spring 22 are assembled.

  The cylinder member 12 is assembled together with the cap 13 and the discharge valve Vd in the large-diameter inner hole 11c2 of the stepped inner hole 11c, and communicates directly with the discharge port 11b to the pump chamber Ro described later via the discharge valve Vd. An annular discharge chamber Rd communicating with each other is formed. The cylinder member 12 is formed in a bottomed cylindrical shape, and has a cylinder hole 12a and a bottom wall 12d in which a valve hole 12b and a valve seat 12c of the discharge valve Vd are formed. It has been retained. The cap 13 is assembled in a liquid-tight manner to the housing body 11, and a communication groove 13 a is formed at a contact portion with the cylinder member 12 to communicate the discharge chamber Rd and the discharge side of the discharge valve Vd.

  The piston 21 is fitted into the small diameter inner hole 11c1 of the stepped inner hole 11c in the housing body 11 through a rubber seal ring 23 and a resin retainer 24 so as to be liquid-tight and slidable in the axial direction. The pump chamber Ro is formed in the small diameter inner hole 11c1 of the stepped inner hole 11c and the cylinder hole 12a, and the suction valve is communicated directly with the small diameter inner hole 11c1 of the stepped inner hole 11c to the suction port 11a. An annular suction chamber Rs communicating with Vs is formed. The piston 21 is slidably engaged with an outer peripheral surface of an eccentric body 31 that is rotationally driven by an electric motor (not shown) at the left end of FIG. When the piston 21 is moved in the axial direction against the biasing force of the piston return spring 22 by the rotation of the eccentric body 31, the volume of the pump chamber Ro is reduced, and the piston 21 is biased in the axial direction by the biasing force of the piston return spring 22. The volume of the pump chamber Ro is increased when it is moved back to the position.

  The piston 21 has a communication hole 21a extending in the axial direction and a communication hole 21b extending in the radial direction. An annular groove 21c is formed corresponding to the communication hole 21b. The axial communication hole 21a communicates with a valve hole 24a formed in the retainer 24 of the suction valve Vs. The communication hole 21b in the radial direction is formed at an intermediate portion of the piston 21, communicates with one end of the communication hole 21a at the intermediate part, and communicates with the annular groove 21c at both ends. The annular groove 21c communicates with the suction chamber Rs.

  The piston return spring 22 is a compression coil spring, and is interposed between the cylinder member 12 and the retainer 24 assembled to the piston 21 with a predetermined preliminary load. The piston 21 and the retainer 24 are eccentric. It is biased toward the body 31.

  The suction valve Vs is assembled fluid-tightly and integrally with the end portion of the piston 21 on the pump chamber side, and is interposed in an inflow path that connects the suction port 11a and the pump chamber Ro. The suction valve Vs is interposed between the retainer 24 and the ball valve body 41 so as to be seated and separated from the valve seat portion 24b formed in the retainer 24, and the ball valve body 41 is inserted into the valve seat portion 24b. A spring 42 that is biased with a small load is provided so as to open when the volume of the pump chamber Ro increases and close when the volume decreases.

  The retainer 24 has a mechanism as an annular seal member that is assembled to the piston 21 and forms a pump Ro in the small-diameter inner hole 11c1 of the stepped inner hole 11c with the piston 21, and as a constituent member of the intake valve Vs. It has the function of The retainer 24 is integrally formed continuously with the valve hole 24a communicating with the suction port 11a, the valve seat part 24b formed at the end of the valve hole 24a on the pump chamber side, and the valve seat part 24b. It has a valve body holding part 24c and a spring holding part 24d, and has an annular seal lip 24e and an annular receiving part 24f, and is liquid-tight in the communication hole 21a of the piston 21 at the left end cylindrical part 24g in FIG. Fitting and fixing.

  The valve body holding part 24c and the spring holding part 24d are composed of six columnar bodies A1 to A6, as shown in FIGS. 2 to 6, and the left end of FIG. 1 of each columnar body A1 to A6 is a valve. 1 functions as the body holding portion 24c, and the right end portion in FIG. 1 of each of the columnar bodies A1 to A6 functions as the spring holding portion 24d. At the right end in FIG. 1 of each of the columnar bodies A1 to A6 functioning as the spring holding portion 24d, a latching portion that engages with one end portion of the spring 42 and restricts the spring 42 from being detached (dropped off) ( Tapered portion) 24d1 is formed. Further, a tapered portion 24h having a large diameter on the pump chamber side is formed on the inner periphery of the right end of FIG. 1 of each columnar body A1 to A6, that is, the inner periphery of the end portion of the retainer 24 on the pump chamber side.

  The annular seal lip 24e is integrally formed on the outer periphery of the retainer 24, and has a shape that restricts the flow of liquid from the pump chamber Ro toward the outer periphery of the piston 21. The annular receiving portion 24f is integrally formed on the outer periphery of the retainer 24 on the pump chamber side from the seal lip 24e, and can receive the piston return spring 22 for returning the piston 21.

  The ball valve body 41 is assembled in advance to the retainer 24 from the right side of FIG. 1 and is housed and held in the valve body holding portion 24c of the retainer 24, and can be seated and separated from the valve seat portion 24b. The spring 42 is assembled to the retainer 24 together with the ball valve body 41 (or after the ball valve body 41 is assembled) from the right side of FIG. 1 and is housed and held in the spring holding portion 24d of the retainer 24. The ball valve body 41 is biased toward the valve seat portion 24b with a small load.

  As shown in FIG. 1, the discharge valve Vd is provided on the discharge side end of the cylinder member 12, that is, on the discharge side of the pump chamber Ro, and is interposed in an outflow passage that communicates the discharge port 11 b and the pump chamber Ro. ing. Further, the discharge valve Vd is interposed between the ball valve body 51 and the cap 13 so as to be seated on and separated from the valve seat 12c formed on the bottom wall 12d of the cylinder member 12, and the ball valve body 51. Is configured to be closed when the volume of the pump chamber Ro is increased and opened when the volume is decreased.

  In the piston pump of this embodiment configured as described above, the piston 21 is pivoted due to the cooperative action of the eccentric body 31 and the piston return spring 22 when the eccentric body 31 is rotationally driven by an electric motor (not shown). By reciprocating in the direction, the volume of the pump chamber Ro is increased or decreased, and the suction valve Vs and the discharge valve Vd function, respectively, and the liquid flows from the suction port 11a toward the discharge port 11b.

  By the way, in the piston pump of this embodiment, the retainer 24 assembled integrally with the piston 21 has the valve hole 24a and the valve seat portion 24b of the intake valve Vs, and is continuously formed integrally with the valve seat portion 24b. The valve body holding portion 24c and the spring holding portion 24d, and the valve body holding portion 24c accommodates and holds the ball valve body 41 that can be seated and separated from the valve seat portion 24b, and the spring holding portion 24d A spring 42 for urging the ball valve body 41 toward the valve seat portion 24b is accommodated and held. For this reason, by assembling the ball valve body 41 and the spring 42 to the retainer 24, the suction valve Vs can be configured separately from the piston 21, and can be sub-assembled. It is possible to improve the sex.

  Further, in the piston pump of this embodiment, the ball valve body 41 and the spring 42 are assembled to the retainer 24 so that the left end portions of the ball valve body 41 and the spring 42 in FIG. 1 contact the tapered portion 24h of the retainer 24. In this state, the ball valve body 41 and the spring 42 are pushed to the left in FIG. 1 and pushed between the columnar bodies A1 to A6. At this time, the tapered portion 24h of the retainer 24 guides the assembly of the ball valve body 41 and the spring 42 between the columnar bodies A1 to A6, and the right end portion of each columnar body A1 to A6 in FIG. It is elastically deformed so that it can be pushed open. For this reason, it is possible to improve the assemblability (insertability) of the ball valve body 41 and the spring 42 to the retainer 24.

  Further, in the piston pump of this embodiment, the valve body holding portion 24c and the spring holding portion 24d of the retainer 24 are configured by six columnar bodies A1 to A6 extending in the axial direction from the valve seat portion 24b, and each columnar shape. A latching portion (tapered portion) 24d1 that engages with one end portion of the spring 42 and restricts the spring 42 from being removed from the retainer 24 is formed at the tip of the bodies A1 to A6. For this reason, it is possible to improve the workability when the retainer 24 is molded with resin and the workability when removing the retainer 24 from the mold.

  In the piston pump of this embodiment, an annular seal lip 24e that restricts the flow of liquid from the pump chamber Ro toward the outer periphery of the piston 21 is integrally formed on the outer periphery of the retainer 24. For this reason, it is possible to reduce the number of parts in the piston pump including the suction valve Vs. Further, a receiving portion 24f of a piston return spring 22 for returning the piston 21 is integrally formed on the outer periphery of the retainer 24 on the pump chamber side from the seal lip 24e. For this reason, it is possible to prevent the piston return spring 22 from interfering with the seal lip 24e and to ensure the function of the seal lip 24e.

  Further, in the piston pump of this embodiment, the valve body holding portion 24c and the spring holding portion 24d of the retainer 24 are constituted by six columnar bodies A1 to A6 extending in the axial direction from the valve seat portion 24b. As shown in FIG. 6, the columnar bodies A1 to A6 are divided into two symmetrical shapes with respect to the virtual plane PL including the axis center line Lo, and the three divided columnar bodies A1 to A3 and A4 to A6 are divided into two. The respective front end portions are integrally joined to form a joined body Aa, Ab.

  The virtual triangles Tr1 and Tr2 formed by connecting the base portions of the three divided columnar bodies A1 to A3 and A4 to A6 are divided into bases a1 and a2 parallel to the virtual plane PL, It is set so as to be an isosceles triangle that is farther from the virtual plane PL than the bases a1 and a2 and has obtuse vertices b1 and b2. The columnar bodies A1 and A6 extending in the axial direction from the vertices b1 and b2 are formed so as to approach the virtual plane PL toward the tip.

  Each of the combined bodies Aa and Ab is formed by integrally connecting the tip portions of the three columnar bodies A1 to A3 and A4 to A6 so that the direction of the ball valve body 41 and the spring 42 is perpendicular to the virtual plane PL. The rigidity of the combined body Aa, Ab can be increased when the retainer 24 is incorporated into the valve body holding part 24c and the spring holding part 24d), but the base parts of the three columnar bodies A1 to A3 and A4 to A6 Since each of the virtual triangles Tr1 and Tr2 formed by connecting the two is an isosceles triangle having the obtuse vertices b1 and b2, the rigidity in the direction perpendicular to the virtual plane PL should not be increased excessively. Is possible. Therefore, it is possible to secure a good assembling property of the ball valve body 41 and the spring 42 to the retainer 24 and to secure a good holding property (assembly reliability) of the ball valve body 41 and the spring 42 assembled to the retainer 24. Can be achieved.

  Further, in the piston pump of this embodiment, the two columnar bodies A2, A3, A4, and A5 extending in the axial direction from the bases a1 and a2 of the isosceles triangle described above are formed so as to sequentially approach each other toward the tip. Has been. For this reason, compared with the case where the two columnar bodies A2, A3 and A4, A5 are parallel to each other, the direction along the virtual plane PL (perpendicular to the direction in which the combined bodies Aa and Ab are expanded). It is possible to increase the rigidity, and when the ball valve body 41 and the spring 42 are assembled into the valve body holding portion 24c and the spring holding portion 24d of the retainer 24, the combined bodies Aa and Ab are in a direction along the virtual plane PL. It is possible to suppress the movement, stabilize the direction in which the combined bodies Aa and Ab are expanded, and improve the assembly of the ball valve body 41 and the spring 42 to the retainer 24.

  In the embodiment described above, as is apparent from FIG. 2, the plane including the center lines of the two columnar bodies A2, A3 and A4, A5 is set to be parallel to the virtual plane PL. The surface including the center line of the columnar bodies A2, A3 and A4, A5 is set so as to approach the virtual plane PL toward the tip ends of the two columnar bodies A2, A3, A4, and A5. Is also possible.

  Further, in the above-described embodiment, the embodiment in which the piston pump is a general piston pump has been described. However, the embodiment can be similarly implemented when the piston pump is a self-priming pump.

It is sectional drawing which shows one Embodiment of the piston pump by this invention. It is the expansion external view which looked at the suction valve shown in FIG. 1 from the pump chamber side. It is a front view of the retainer single-piece | unit shown in FIG. It is a right view of the retainer single-piece | unit shown in FIG. It is a perspective view of the retainer single-piece | unit shown in FIG. It is a skeleton figure which shows roughly the structure of the six columnar bodies in the retainer shown in FIGS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Pump housing, 11 ... Housing main body, 11a ... Inlet port, 11b ... Discharge port, 11c ... Stepped inner hole, 11c1 ... Small diameter inner hole, 12 ... Cylinder member, 13 ... Cap, 21 ... Piston, 22 ... Piston return Spring, 23 ... Seal ring, 24 ... Retainer, 24a ... Valve hole, 24b ... Valve seat part, 24c ... Valve body holding part, 24d ... Spring holding part, 24d1 ... Latching part, 24e ... Seal lip, 24f ... Receiving Part, 24g ... cylindrical part, 24h ... tapered part, Vs ... suction valve, 41 ... ball valve body, 42 ... spring, Vd ... discharge valve, 51 ... ball valve body, 52 ... spring, Ro ... pump chamber, A1- A6 ... Columnar body, Lo ... Axis center line, PL ... Virtual plane, Tr1, Tr2 ... Virtual triangle, a1, a2 ... Base, b1, b2 ... Apex of obtuse angle

Claims (2)

A pump housing (10) having a suction port (11a) and a discharge port (11b) and having an inner hole (11c) communicating with the suction port (11a) and the discharge port (11b); A piston (21) that is assembled in the hole (11c) to form a pump chamber (Ro) and is reciprocated in the axial direction to increase or decrease the volume of the pump chamber (Ro), and provided in the piston (21) A suction valve (Vs) that is interposed in an inflow passage that connects the suction port (11a) and the pump chamber (Ro) and that opens when the volume of the pump chamber (Ro) increases, and closes when the volume decreases, and the discharge port ( 11b) and a discharge valve (Vd) that is interposed in an outflow passage that communicates the pump chamber (Ro) and opens when the volume of the pump chamber (Ro) decreases, and closes when the volume increases. 1) is reciprocated in the axial direction to increase or decrease the volume of the pump chamber (Ro) so that the liquid flows from the suction port (11a) toward the discharge port (11b). In piston pump,
The suction valve (Vs) includes a valve hole (24a) communicating with the suction port (11a), a valve seat part (24b) formed at a pump chamber side end of the valve hole (24a), A retainer (24) is provided which has a valve body holding portion (24c) and a spring holding portion (24d) which are integrally formed continuously with the seat portion (24b), and which is integrally assembled with the piston (21). In addition, the valve body (41) which is accommodated and held in the valve body holding portion (24c) of the retainer (24) and can be seated and separated from the valve seat portion (24b), and the spring of the retainer (24) A spring (42) that is accommodated and held in the holding portion (24d) and biases the valve body (41) toward the valve seat portion (24b);
The valve body holding part (24c) and the spring holding part (24d) of the retainer (24) are constituted by six columnar bodies (A1 to A6) extending in the axial direction from the valve seat part (24b). These columnar bodies (A1 to A6) are divided into two symmetrical shapes with respect to the virtual plane (PL) including the axial center line (Lo), and three divided columnar bodies (A1 to A3 and Each tip of A4 to A6) is integrally joined, and each virtual triangle (Tr1, formed by connecting the roots of three divided pillars (A1 to A3 and A4 to A6)) Tr2) has a base (a1, a2) parallel to the virtual plane (PL) and an obtuse angle apex (b1, b2) away from the virtual plane (PL) from the base (a1, a2). A piston pump characterized by being an isosceles triangle. 2. The piston pump according to claim 1, wherein two columnar bodies (A 2, A 3 and A 4, A 5) extending in the axial direction from the bottom end of the isosceles triangle are formed so as to sequentially approach each other toward the tip. Piston pump characterized by that.

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