JPH0429111Y2 - - Google Patents

Description

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

<Prior art> In a conventional pump device, as shown in FIG. 3, the surplus flow discharged from the pump in order to supply the power steering device with the fluid adjusted to a substantially constant flow rate by the flow rate regulating valve 1 has a flow rate of The fluid in the fluid tank is bypassed from the regulating valve 1 through the bypass passage 2 to the pump suction port, and in order to increase the pump suction efficiency by utilizing the kinetic energy of this bypass flow, the fluid in the fluid tank is introduced into the bypass passage 2. Some pumps are provided with a fluid supply path 4 to supercharge the fluid within the pump suction path.

<Problems to be solved by the invention> However, in a pump device having such a structure, when the pump is rotated at a high rotational speed and is under no load, the bypass passage 2 opens wide relative to the valve housing hole, and the entire bypass passage is closed. Since the bypass flow flows out over a period of time, most of the bypass flow leaves the fluid supply path 4, and as a result, the velocity energy of the bypass flow cannot be fully utilized, and a sufficient supercharge effect cannot be expected. Ta. For this reason, it was not possible to increase the suction efficiency as desired, and it was not possible to effectively prevent the occurrence of cavitation and the occurrence of abnormal noise and vibration associated with it.

<Means for Solving the Problems> The present invention has been made in order to solve the problems of the conventional art. a fluid supply path that opens into the bypass passage at a position eccentrically outward toward the side where negative pressure is generated; A fitting hole is formed that opens into the bypass passage on the side where the fluid flows, and a guide rod that deflects the flow of excess fluid flowing through the bypass passage toward the fluid supply passage is fitted into this fitting hole. .

<Operation> In the above configuration, the fluid flowing out from the valve storage hole into the bypass passage is guided by the guide rod and deflected toward the fluid supply path, and all the bypass flow flows out with force when approaching the fluid supply passage.
The energy of the entire flow rate of this bypass flow is effectively utilized to efficiently supercharge the fluid in the fluid supply path.

<Examples> Examples of the present invention will be described below based on the drawings. In FIG. 1, reference numeral 10 denotes a pump housing, and a hollow chamber 11 with a bottom is formed in this pump housing 10, and this hollow chamber 11 is open at one end surface of the pump housing 10. This hollow chamber 1
A through hole 13 is provided in the lid member 12 that closes the opening of 1.
A rotary shaft 14 is inserted through the through hole 13 and rotatably supported by bearings 15a and 15b.

The hollow chamber 11 has a cam ring 16 in contact with one end surface of the lid member 12, a side plate 17 in contact with the other side of the cam ring 16, and a pressing plate 18 in contact with the other side of the side plate 17.
A spring 19 is compressed and inserted between the press plate 18 and the pump housing 10. A cam surface 20 is formed on the inner periphery of the cam ring 16, and a rotor 22 that holds a plurality of vanes 21 whose outer ends are in sliding contact with the cam surface 20 in a radially slidable manner is housed within the cam ring 16. . The rotor 22 is splined to one end of the rotating shaft 14.

The left side surface of the rotor 22 and the left end surface of the vane 21 are in sliding contact with the end surface of the lid member 12, and the right side surface of the rotor 22 and the right end surface of the vane 21 are in sliding contact with the side surface of the side plate 17, and each sliding surface has a sealing effect. will be done. As a result, a plurality of pump chambers partitioned by the vanes 21 are formed between the cam surface 20 of the cam ring 16 and the rotor 22, and the volume of each pump chamber changes as the rotor 22 rotates. Suction ports 25 and 26 are formed in the lid member 12 and side plate 17 corresponding to the pump chamber that performs an expansion stroke, and discharge grooves 27 are formed in the lid member 12 and side plate 17 corresponding to the pump chamber that performs a compression stroke. ,2
8 is formed. A suction port 25 formed in the lid member 12 and a suction port 26 formed in the side plate 17 are communicated with each other through a passage 29 formed between the cam ring 16 and the pump housing 10. Furthermore, on the side of the side plate 17, this suction port 26 is connected to the pressure plate 1.
8, and communicates with the center through hole 18a of the pressing plate 18. A discharge port 27 formed in the side plate 17,
28 is connected to the pressure chamber 3 through the through hole of the pressure plate 18.
5.

The pump housing 10 has a valve housing hole 36 orthogonal to the axis of the rotating shaft 14, as shown in FIG.
Then, one end is opened in this valve storage hole 36 and the pressure chamber 35 is opened.
an introduction passage 37 whose other end is open to the center through-hole 18a of the press plate 18;
Bypass passage 38 whose other end is open to valve storage hole 36
A delivery path 40 is provided with one end open to the pressure chamber 35 and the other end open to the outside of the pump housing 10. A flow rate adjustment valve 43 is slidably inserted into the valve storage hole 36 in order to close the communication path between the introduction passage 37 and the bypass passage 38 and to adjust the degree of opening of the communication path. A first valve chamber 41 and a second valve chamber 42 are formed at both ends. The second valve chamber 42 is provided with a spring 44 that presses the flow rate regulating valve 43, and normally blocks communication between the first valve chamber 41 and the bypass passage 38.

The delivery passage 40 is provided with a constriction part 45, and the fluid that has passed through the constriction part 45 is guided to the first valve chamber 42 through an unillustrated passage. Aperture part 45
The fluid that does not pass through the pressure chamber 35, that is, the fluid discharged into the pressure chamber 35, is guided to the first valve chamber 41 through the introduction passage 37. As a result, the pressure before passing through the throttle part 45 and the pressure after passing through the throttle part 45 act on both end faces of the flow rate regulating valve 43, so the opening degree of the bypass passage 38 is adjusted to keep the pressure drop in the throttle part 45 at a constant value. do. Therefore, the flow rate passing through the constriction part 45 remains almost constant and is sent to the power steering device from the discharge port, while the surplus flow discharged by the pump is bypassed from the first valve chamber 41 to the bypass passage 38 and is transferred to the pump suction port 2.
It is returned to 5,26.

Furthermore, a fluid supply path 60 and a fitting hole 70 are formed in the pump housing 10 . This fluid supply path 60 opens into the bypass passage 38 at a position perpendicular to the central axis of the bypass passage 38 and slightly eccentrically outward with respect to the central axis, and communicates with the reservoir 50 at the other end. has been done. Further, the fitting hole 70 is located on the opposite side of the fluid supply path 60 across the bypass passage 38, extends in a direction parallel to the fluid supply passage 60, and has one end opened to the bypass passage 38.
A guide rod 71 having a circular cross section is fitted into the fitting hole 70, and the guide rod 71 deflects the fluid passing through the bypass passage 38 toward the fluid supply passage 60.

<Function> When the pump is driven, the fluid in the fluid tank 50 flows through the fluid supply path 60, the bypass path 38, and the passage groove 30 of the pressing plate 18 to the suction ports 25, 26.
The liquid is sucked into the pump chamber, and is discharged from the discharge port 27 of the side plate 17 to the pressure chamber 35 through the through hole of the press plate 18. The fluid discharged into the pressure chamber 35 passes through the constriction part 45 and is sent to the power steering device from the discharge port, and the fluid returned from the power steering device flows into the reservoir 50 and flows through the fluid supply path 6.
0 and sucked into the pump again.

If the pump rotation speed is low, the pump discharge flow rate is also small, so the differential pressure before and after the throttle part 45 is small.The flow rate adjustment valve 43 is located at one end by the pressure of the spring 44 and closes the bypass passage 38, and the full volume throttle part is closed. 45 to the power steering device, but as the rotation speed increases, the discharge flow rate also increases, and the differential pressure before and after the throttle part 45 increases, causing the flow rate adjustment valve 43
moves against the pressing force of the spring 44 to open the bypass passage 38 and bypass the excess flow to the bypass passage 38. Reservoir 50 by bypass flow
The fluid is drawn in at the connection point between the fluid supply path 60 and the bypass path 38 and is supercharged to increase the pump suction pressure.

At this time, the bypass flow that has flowed into the bypass passage 38 from the valve storage hole 36 is deflected toward the fluid supply path 60 side by the guide rod 71 fitted in the fitting hole 70, so the velocity energy of the bypass flow is effective. This makes it possible to further improve the efficiency of suction into the suction ports 25 and 26.

<Effects of the invention> As described above, the present invention has a guide rod fitted into the fitting hole that deflects the flow of excess fluid flowing through the bypass passage toward the fluid supply passage, so that the entire amount of the bypass flow is directed to the opening of the fluid supply passage. As a result, the velocity energy of the bypass flow can be utilized to the maximum, and the suction efficiency can be significantly improved compared to the conventional method. Therefore, even when the pump rotates at high speed, cavitation can be reliably prevented and the generation of noise can be effectively eliminated.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a pump device showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the - line in Fig. 1, and Fig.
The figure is a partial sectional view of a conventional pump device. DESCRIPTION OF SYMBOLS 10... Pump housing, 38... Bypass passage, 43... Flow rate adjustment valve, 60... Fluid supply path, 70... Fitting hole, 71... Guide rod.

Claims (1)

[Scope of utility model registration request] A valve storage hole is formed in the housing, a flow rate adjustment valve is fitted into the valve storage hole, and the fluid control valve is slid to adjust the pressure fluid discharged from the discharge port to a substantially constant flow rate. In the pump device, the housing is configured to discharge excess flow from the outlet and bypass the excess flow to the pump suction port via a bypass passage opened to the valve storage hole and communicated with the valve storage hole by movement of the flow rate adjustment valve. a fluid supply path extending perpendicularly to the bypass passage and opening into the bypass passage at a position eccentrically outward toward the side where negative pressure is generated due to surplus flow flowing diagonally through the bypass passage; A fitting hole is formed that extends parallel to the bypass passage and opens into the bypass passage on a side opposite to the fluid supply passage and toward which the excess flow is directed, and the bypass passage is inserted into the fitting hole. 1. A pump device comprising a guide rod fitted therein for deflecting a flow of surplus fluid flowing through the fluid supply path toward the fluid supply path.