JPS6132159Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a vane pump for supplying pressure fluid to a power steering device or the like.

<Prior art> A vane pump used to supply pressure fluid to a power steering device has a rotor driven by an engine, so the pump discharge flow rate increases as the engine speed increases. Since the flow rate also increases, the excess flow is bypassed to the suction side of the pump using a flow rate regulating valve.

By the way, this type of vane pump generally has two sets of suction and discharge ports on the circumference, and suction and discharge are performed at a cycle of 180 degrees. It is necessary to divide the flow equally between the two sets of suction ports to avoid insufficient suction to the suction ports.

For this purpose, conventionally, as described in Japanese Patent Publication No. 45-9110, the cam ring is held centrally on the inner wall of a casing in which two end plates and a cam ring disposed therebetween are housed coaxially. A plurality of centering segments are protruded, and a streamlined centering segment facing the bypass hole divides fluid from the bypass hole into two sets of suction ports.

<Problems to be solved by the invention> However, the above-mentioned conventionally known pumps,
Because the streamlined centering segment is formed on the inner wall of the casing, it is difficult to manufacture the casing, and the streamlined centering segment is arranged on the side of the annular space between the casing and the cam ring. Therefore, in configurations where the inlet opens at right angles to the axis of rotation, only a portion of the fluid drawn through the inlet is affected by the centering segment; There was a problem in that it was difficult to evenly divide the fluid into the two sets of suction ports.

<Means for Solving the Problems> The present invention was developed in view of the above-mentioned conventional problems, and its structure is such that an annular groove that communicates with two suction ports is formed in the pump housing so as to surround the cam ring. A suction port communicating with the oil tank is opened in the annular groove at an intermediate portion between the two suction ports, and the fluid sucked from the suction port is connected to the outer periphery of the cam ring in a manner corresponding to the suction port. A flow dividing protrusion that divides the flow in the circumferential direction toward the suction port is provided so as to protrude over the entire width of the cam ring.

<Function> With the above configuration, the entire amount of fluid sucked into the annular groove from the suction port is divided into two circumferential flows toward the two suction ports by the flow dividing protrusion protruding from the outer periphery of the cam ring. Evenly inhaled into the suction port.

<Examples> Examples of the present invention will be described below based on the drawings.

In FIGS. 1 and 2, reference numeral 10 denotes a pump housing, in which a hollow chamber 11 with a bottom is formed, and this hollow chamber 11 is open at one end of the pump housing 10. As shown in FIG. An end cover 12 is fixed to one end of the pump housing 10 to close the opening thereof. Inside the hollow chamber 11 surrounded by the pump housing 10 and the end cover 12, one side is provided with the end cover 1.
A cam ring 13 facing the pump 2 and a pressure plate 14 facing the other side of the cam ring 13 are housed, and a compression spring 15 is inserted between the pressure plate 14 and the pump housing 10 in a resilient state. . The cam ring 13 and the pressure plate 14 are connected to two positioning pins 1 supported between the pump housing 10 and the end cover 12.
The phase is determined by 6 and 17. A substantially elliptical cam surface 18 is formed on the inner circumference of the cam ring 13, and a plurality of vanes 19 are in sliding contact with this cam surface 18.
A rotor 20 that is slidably held in the radial direction is housed in the cam ring 13, and this rotor 2
0 is spline-engaged with one end of a rotating shaft 21 rotatably supported on the pump housing 10. As a result, a plurality of pump chambers are formed between the cam surface 18 of the cam ring 13 and the rotor 20 by the vanes 19, and the volume of each pump chamber changes as the rotor 20 rotates.

On each side of the pressure plate 14 and the end cover 12, which are in contact with both sides of the cam ring 13, two suction ports 23, 24 are arranged opposite to each other in the diametrical direction of the rotating shaft 21, corresponding to the pump chambers that perform the expansion stroke. Two discharge ports 25 and 26 are formed to face each other in the diametrical direction of the rotating shaft 21, corresponding to a pump chamber that performs a compression stroke. The suction ports 23 and 24 communicate with an annular groove 27 formed in the hollow chamber 11 so as to surround the cam ring 13, and a suction port 28 in the annular groove 27 connects to the rotation shaft 21 at an intermediate portion between the two suction ports 23 and 24.
The opening is perpendicular to the axis (radial direction). The suction port 28 communicates with a suction passage 30 leading to an oil tank 29 installed on the pump housing 10, and also with a bypass passage 32 whose opening degree is adjusted by a flow rate regulating valve 31. Further, the discharge ports 25 and 26 are communicated with a pressure fluid outlet via a discharge passage 33 and a crest passage (not shown), and the surplus flow of the pressure fluid discharged into the discharge passage 33 is passed through the bypass passage by the flow rate regulating valve 31. 3
2 is now bypassed.

The suction port 28 is provided on the outer periphery of the cam ring 13.
The flow dividing protrusions 35 are provided over the entire width of the cam ring 13 so as to face the entire opening of the suction port 28. The flow dividing protrusions 35 are arranged radially from the suction port 28 into the annular groove 2.
The flow of fluid drawn into the intake port 2
The cam ring 13 is formed in a generally mountain-like shape with a smoothly curved surface that divides the circumferential flow toward the intake ports 23, 24 in half.
Stationary projections 37, 38 are provided over the entire width of the cam ring 13 in correspondence with the ends of the intake ports 23, 24, and these stationary projections 37, 38 act to receive the circumferential flow diverted by the flow diverting projections 35 at the terminal ends of the intake ports 23, 24 and guide it to the intake ports 23, 24. The cam ring 13 is made of a sintered material, and the flow diverting projections 35 and the stationary projections 37,
The reference numeral 38 is formed integrally with the cam ring 13 .

In the above configuration, when the rotating shaft 21 is driven by the engine, the rotor 20 rotates, fluid is sucked into the two suction ports 23 and 24 from the suction port 28, and pressure is drawn from the discharge ports 25 and 26. Fluid is discharged and pumped to a power steering device or the like. At this time, the fluid sucked into the annular groove 27 from the suction port 28 is equally divided into two parts by a flow dividing protrusion 35 protruding from the outer periphery of the cam ring 13, and flows toward the two suction ports 23 and 24. Diversion protrusion 35
The fluid divided by the stationary protrusions 37 and 38 is guided to the suction ports 23 and 24, respectively, so that the suction fluid efficiently flows to the suction ports 23 and 24.
is inhaled. Further, the flow dividing protrusion 35 is connected to the suction port 2.
The cam ring 13 is placed so as to face the entire opening of 8.
Since it is formed over the entire width of the suction port 28, an effective diversion effect can be performed on the entire amount of fluid sucked in from the entire opening of the suction port 28, even when suction is taken perpendicular to the axis of rotation. Moreover, since the flow dividing protrusion 35 is formed on the outer periphery of the cam ring 13, processing is much easier than forming it inside the pump housing 10.
If it is integrally molded, it will be easier to process.

3 and 4 show another embodiment of the present invention, which differs from the previously described embodiments in that the suction port 128 is opened at an angle to the annular groove 27, and The protruding flow dividing protrusion 135 is also curved in the width direction of the cam ring 13.
Therefore, the fluid sucked obliquely into the annular groove 27 is diverted in the circumferential direction along the width direction of the cam ring 13 by the diverting protrusion 135, and the same effect as in the previous embodiment can be expected.

Note that parts that are the same as those in the previous embodiment are given the same symbols, and their explanations will be omitted.

<Effects of the invention> As described above, the present invention has a flow dividing protrusion on the outer periphery of the cam ring that divides the fluid sucked from the suction port into a circumferential flow toward the two suction ports, all over the opening of the suction port. In addition, two stationary protrusions are formed over the entire width of the cam ring to receive the flow in the circumferential direction at the terminal ends of the two suction ports. The entire amount of fluid sucked from the entire area of the opening can be efficiently and evenly divided into the two suction ports by the flow dividing protrusion, and the divided fluid can be smoothly sucked into the two suction ports by the stationary protrusion. This has the effect of preventing insufficient suction into the suction port.

Moreover, according to the present invention, the flow dividing protrusion and the two
Since the two stationary protrusions are integrally sintered and formed on the outer periphery of the cam ring, the flow dividing protrusion and the stationary protrusion can be formed very easily.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a vane pump showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the - line arrow in Fig. 1,
FIG. 3 is a sectional view of a vane pump showing another embodiment of the present invention, and FIG. 4 is a view taken along the arrow in FIG. 10... Pump housing, 12... End cover, 13... Cam ring, 14... Pressure plate, 19... Vane, 20... Rotor, 21...
Rotating shaft, 23, 24...Suction port, 25, 26
... Discharge port, 27 ... Annular groove, 28 ... Suction port, 35 ... Diversion projection, 37, 38 ... Stationary projection.

Claims (1)

[Scope of utility model registration request] A pump housing, a cam ring housed in the pump housing, a pressure plate having two sets of suction ports and discharge ports spaced apart on the circumference on a surface facing the cam ring, and a pressure plate that slides on the cam surface of the cam ring. A vane pump comprising a rotor holding a plurality of vanes in contact with each other,
An annular groove that communicates with the two sets of suction ports is formed in the pump housing so as to surround the cam ring, and an inlet that communicates with the oil tank and a bypass passage whose opening is adjusted by a flow rate regulating valve is formed in the annular groove. opens in the middle of the two suction ports,
The fluid sucked from the suction port is placed on the outer periphery of the cam ring, corresponding to the entire opening of the suction port.
A flow dividing protrusion that separates the flow in the circumferential direction toward one suction port is provided protruding across the entire width of the cam ring, and two stationary protrusions that catch the divided circumferential flow into two at the terminal end of the suction port are provided. A vane pump in which a protrusion is provided extending over the entire width of a cam ring, and these flow dividing protrusions and stationary protrusions are sintered and formed integrally with the cam ring.