JPS59221488A - Vane pump - Google Patents

Abstract

PURPOSE:To prevent the unbalance of suction pressure as well as the noise of the vane pump by a method wherein a plug, fitted into a suction path communicating with an annular groove, is provided with a protuberance, distributing fluid from the suction path uniformly into the annular groove, so as to be biased to one side from the center of the suction path. CONSTITUTION:The annular groove 27 is provided with an opening hole 35 at the intermediate part of suction ports 23, 24 so as to be biased to a direction orthogonal to the axial line of a rotary shaft 21 while this hole is communicated with the suction path 37. The plug 28 is fitted into the other end of the path 37 and is provided with a column-shape base part 28a having the same diameter as the suction path 37 as well as a flat flow distributing protuberance 28b being projected to a position biased with respect to the central axial line by the length of (1) while the column-shape base part 28b is fitted into and held by the suction part 37.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a vane pump that supplies pressurized fluid to a power steering device or the like.

<Prior art> A conventional vane pump is formed by combining the surplus flow bypass-controlled by the flow ffl[j regulating valve and the fluid in the oil tank in a bypass passage, and then surrounding the cam ring from the suction passage. A set of suction boats is provided with suction via an annular groove.

However, in such conventional vane pumps, excess flow is biased toward one side of the bypass passage from the flow control valve, and due to this influence, the fluid is not evenly divided into the annular groove. A suction pressure as shown by the solid line in FIG. 1 was generated in one of the pair of open suction boats, and a suction pressure as shown in the phantom line was generated in the other suction boat, resulting in a large imbalance in the suction pressures. This tendency tends to cause a larger unbalance as the rotation of the vane pump shifts from N1 to N5 to a high speed rotation range, and there is a problem in that abnormal noise is generated due to this unbalance of suction pressure.

<Purpose of the Invention> The present invention has been made in order to solve such conventional problems, and its purpose is to prevent imbalance of suction pressure and to prevent abnormal noise from occurring. be.

<Structure of the Invention> The present invention has been made to achieve the above object,
The present invention relates to a vane pump characterized in that a stopper attached to a suction passage has a flow dividing protrusion that evenly divides fluid from the suction passage into an annular groove so as to protrude from the center of the suction passage to one side.

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

In FIGS. 2 and 3, IO indicates a pump housing, and a hollow chamber 11 with a bottom is formed in this pump housing, and this hollow chamber 11 opens at one end of the pump housing IO. 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 IO and the end cover 12, a cam ring 13 whose negative side faces the end cover 12, and a pressure plate 14 that contacts the other side of the cam ring 13 are housed. A compression spring 15 is inserted between the pressure plate 14 and the pump housing IO in a resilient state. Cam ring 13 and pressure plate 14 are connected to pump housing 10
It is positioned by two positioning pins 16 and 17 supported between and the end cover 12.

A substantially elliptical cam surface 18 is formed on the inner circumference of the cam ring 13, and a rotor 20 that holds a plurality of vanes 19 in sliding contact with the cam surface 18 so as to be slidable in the radial direction is attached to the cam ring 13.
3, and this rotor 20 is splined to one end of a rotating shaft 21 rotatably supported by the pump housing 10. With this, the cam ring 13
A plurality of pump chambers partitioned by bays 719 are formed between the cam surface 18 and the rotor 20, and the volume of each pump chamber changes as the rotor 20 rotates.

a pressure plate 1 facing both sides of the cam ring 13;
4 and the end cover 12, two suction boats 23 and 24 are formed opposite to each other in the diametrical direction of the rotating shaft 21, corresponding to a pump chamber that performs an expansion process, and a pump chamber that performs a compression process. 25.2
6 are formed to face each other in the diametrical direction of the rotating shaft 21. The suction bows) 23 and 24 are communicated with an annular groove 27 formed in the hollow chamber 11 so as to surround the cam ring 13,
Further, the discharge bow 1-25, 26 is communicated with the °ζ pressure fluid outlet via the discharge passage 33 and the throttle passage of the circuit, and the surplus flow of the pressure fluid discharged to this discharge passage 33 is passed through the bypass passage by the flow rate regulating valve 31. 32 is bypassed.

The annular groove 27 has an opening hole 35 offset in a direction (radial direction) perpendicular to the axis of the rotating shaft 21 in the middle of the suction bows 1-23, 24, and the suction f! Road 37
is communicated. This suction passage 37 has one end communicating with a replenishment passage 30 passing through the oil tank 29 and the bypass passage 32, and a stopper 28 is fitted at the other end.

As shown in FIGS. 4 and 5, this plug 28 has a cylindrical base 28a having the same diameter as the inner diameter of the suction passage 37, and a β A flat flow dividing protrusion 2 that protrudes in an offset position.
8b, and this cylindrical base 28b is connected to the suction passage 3.
7 is maintained as positive. In this held state, a space is formed between the flow dividing projection 28b and the suction passage 37, and the suction passage 37 and the annular groove 27 are communicated through this space. In addition, in the held state, the flow dividing protrusion 28b is located at a position offset to one side from the central axis of the suction passage 37, that is, due to the influence of the surplus flow from the flow rate adjustment valve 31, the flow dividing protrusion 28b is located on the side where the force of the fluid is large. Ru.

Therefore, by locating the flow dividing protrusion 28b on the side where the force is greater, the fluid from the bypass passage 32 can be equally divided and flow into the annular groove 27 with the same force.

Since the vane pump of the present invention is configured as described above, when the rotary shaft 21 is driven by the engine, the rotor 20 rotates, and as a result, fluid is sucked into the suction port 1-23, 24 from the supply passage 30. At the same time, pressurized fluid is discharged from the discharge boats 25 and 26 and is sent under pressure to a power steering device and the like.

At this time, since the surplus flow from the flow rate adjustment valve 31 flows into the bypass passage 32 in a specific direction, the momentum of the fluid in the bypass passage 32 and the suction passage 37 becomes non-uniform. However, in the present invention, the flow dividing protrusion 28b is disposed at a position biased with respect to the central axis of the suction passage 37, that is, biased toward the side where the force of the fluid is large, and the action of the flow dividing protrusion 28b reduces the force and flow rate of the fluid. is equally divided into two parts and flows into the annular groove 27, so that the suction pressures of the suction bows 1-23 and 24 become equal.

Note that the shape of the plug 28 is not limited to the above embodiment, but as shown in FIGS. 6 and 7, both sides of the plug 28 may be cut out diagonally and guided to both sides of the flat flow dividing protrusion. It is also possible to form a surface 28c and allow the fluid to flow into the annular groove 35 more smoothly by the guiding action of the guide surface 28c.

<Effects of the Invention> As described above, in the present invention, a plug is fitted into the suction passage communicating with the annular groove, one end of the plug is connected to the suction passage, and the other end is connected to the outer peripheral surface of the cam ring. Since it has a configuration in which a vertically opening communication hole is formed, it has the advantage of preventing an imbalance in suction pressure and preventing the generation of abnormal noise.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a characteristic diagram showing changes in suction pressure in a conventional vane pump, and FIG.
The figure is a cross-sectional view of the vane pump of the present invention, FIG. 3 is a cross-sectional view taken along the line mm in FIG. 2, FIG. 4 is a front view of the plug, and FIG. FIG. 6 is a front view showing another embodiment of the stopper, and FIG. 7 is a view taken in the direction of the arrow ■ in FIG. 10...Pump housing, 13...Cam ring,
14...Pressure plate, 18...Cam surface, 19...
・Vane, 20...Rotor, 23...Suction boat,
25... Discharge boat, 27... Annular groove, 28...
Plug, 28a...Communication hole, 28b...Diversion protrusion,
29...Oil tank, 37...Suction passage. Patent applicant Toyota Machinery Co., Ltd.

Claims (1)

[Claims] (11 pump housing, a cam ring housed in this pump housing, and 2 parts on the surface facing the cam ring.
In the vane pump, the vane pump includes a pressure foot formed by separating a set of suction boats and a discharge boat on the circumference, and an L coater holding a plurality of rings that are in sliding contact with the cam surface of the cam ring. 2 above on the housing
An annular groove that communicates with the set of suction bores is formed to surround the cam ring, a suction passage whose one end passes through the oil tank is communicated with the annular groove, a stopper is attached to the suction passage, and a plug is attached to the suction passage. 2. A vane pump characterized in that the filling stopper is provided with flow dividing protrusions which evenly divide the fluid from the suction passage into the annular groove and protrude from the center of the suction passage to one side.