JP2001020890A - Pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of cavitation to the suction side of a pump and to perform quiet operation through reduction of the generation of cavitation noise. SOLUTION: A branch body 6 positioned opposite to the opening of a return pipe 50 communicating with an oil feed destination is situated at the internal part of a reservoir tank T formed such that the outside of a pump body 1 is surrounded by a cylindrical tank cylinder 5. A part of return oil from the oil feed destination is branched by a branch protrusion 62 and guided in the suction pipe 17 of the pump body 1 through a lead-through pipe 64 and a flow of working oil sucked in a suction chamber 18 through a suction pipe 17 is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump device in which a hydraulic fluid in a reserve tank is sucked into a pump, pumped to a destination, returned to the reserve tank, and circulated.

[0002]

2. Description of the Related Art In recent years, automobiles are equipped with a number of auxiliary devices, such as a power steering device and an automatic transmission, which are operated by hydraulic pressure and assist driving operation. In order to generate the pressure, a pump device including a pump main body having a pump function, a reserve tank for storing hydraulic oil, and a pipe for communicating these with an oil supply destination is mounted.

[0003] As a pump body of such a pump device, since it is required to generate high hydraulic pressure while being small, a rotary displacement pump such as a vane pump or a gear pump is used. A gear pump that can provide pump efficiency is often used. Further, the above pump device is generally driven by an engine as a drive source. However, an engine that changes the rotation speed in a wide range during traveling is not preferable as a drive source. The consumption of power for driving leads to a decrease in fuel efficiency, and further, there are various problems such as a limitation in the arrangement position of the pump for transmission from the engine.
In recent years, an electric pump having a drive source of an electric motor driven by power supply from a vehicle-mounted battery has been used instead of an engine.

Further, as disclosed in Japanese Patent Application Laid-Open No. Hei 10-82377 by the present applicant, an electric motor is attached to one side of a pump body via a cylindrical support bracket, and is attached to the same side of the pump body. Connect to the protruding pump shaft,
A bottomed cylinder is attached to the support bracket so as to surround the outside of the pump body to form a reserve tank, and the reserve tank and the electric motor are integrally formed with the pump body to improve mountability on a vehicle. Some are configured as pump devices.

[0005]

In the pump device constructed as described above, the gear pump used as the pump main body performs an intermittent discharge operation in accordance with the rotation of the gear pump. Is inevitable, and there is a problem that noise (pulsation noise) due to the pulsation is generated. To reduce such pulsation noise, the discharge amount per one rotation has conventionally been reduced. While reducing the pulsation component, the rotational speed of the pump body is increased to ensure a desired flow rate.

However, during operation of the pump body, various noises having a frequency related to the rotational speed other than the pulsation noise such as cavitation noise (cavitation noise) generated on the suction side are generated. Therefore, when the rotation speed of the pump body is increased for pulsation countermeasures, the frequency of these noises is generally increased, and in particular, the cavitation sound is heard as harsh high-frequency sound, and the driver has unnecessary anxiety. There was a problem of giving a feeling.

Further, in a pump device using an electric motor as a driving source, various controls can be performed according to a running state. For example, in a pump device used as a source of operating hydraulic pressure of a power steering device. Since the power steering device needs to be operated only while steering is being performed, the steering is performed in order to suppress unnecessary power consumption for driving the pump body and improve overall fuel efficiency. Control is performed to detect whether or not an operation has been performed, to drive the pump body only during the operation, and to stop the drive during straight running without steering, so-called stop / go control.

However, when the stop / go control as described above is performed, the flow on the suction side of the pump main body is not changed during a transitional period after the pump main body in the rest state is started in response to the detection of the steering operation. It becomes stable and cavitation easily occurs. As a result, every time a steering operation is performed,
A harsh high-frequency cavitation sound is generated at a high level, and there is a problem that the driver who listens to the cavitation sound has a further anxiety feeling.

The present invention has been made in view of such circumstances, and is intended to suppress cavitation generated on the suction side of a pump and to operate at a high speed in order to prevent pulsation on the discharge side. Another object of the present invention is to provide a pump device that can effectively reduce the occurrence of high-frequency cavitation noise generated in a transitional period immediately after startup and does not cause a driver to feel useless anxiety.

[0010]

According to a first aspect of the present invention, there is provided a pump device for supplying a working fluid inside a reserve tank provided with a return port from a liquid supply destination through a suction port opened into the reserve tank. A pump device configured to suck into a pump main body, pressurize the inside of the pump main body, and send out the liquid to a liquid sending destination, and return liquid from the liquid sending destination to a reserve tank through the return port to be used in circulation. And a diversion means disposed inside the reserve tank and diverting a part of the return liquid from the return port to guide the liquid to the suction port.

In the present invention, a part of the hydraulic fluid returning from the liquid supply destination to the reserve tank is returned to the suction side of the pump main body by the diversion means arranged facing the return port to stabilize the flow on the suction side. To suppress the occurrence of cavitation and reduce high-frequency cavitation sound.

Further, in the pump device according to the second invention, the reserve tank is configured such that a bottomed cylindrical body surrounding the outside of the pump body is supported by a support bracket of the pump body. And

In the present invention, a bottomed cylinder is supported by a support bracket of the pump body so as to surround the outside of the pump body, and the inside of the cylinder is used as a reserve tank. And are integrally configured.

Further, in the pump device according to a third aspect of the present invention, the flow dividing means is constituted by a plate member which is attached to a return port opened on a peripheral surface of the cylindrical body and has a convex portion crossing the return port. There is a feature.

In the present invention, a plate member provided with a convex portion on a part of the inside of a cylinder constituting a reserve tank is provided.
The convex portion was attached so as to cross the return port opened on the peripheral surface of the cylindrical body, and the return liquid returning from the liquid sending destination via the return port was diverted to both sides by the action of the convex portion, and was diverted to one side. A part of the return liquid is led to the suction port of the pump body, and the return liquid diverted to the other side is returned into the reserve tank.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a side view of a main part of a pump device according to the present invention, which is cut away, and FIG.
FIG. 2 is a cross-sectional view taken along line II.

The pump device according to the present invention has a short cylindrical support bracket 2 for supporting the pump body 1 on one side.
An electric motor 3 for driving is attached to the other surface of the support bracket 2, and a pump shaft 10 as an input shaft to the pump body 1 and a motor shaft 30 as an output shaft of the electric motor 3 are connected to the support bracket 2.
, Are connected coaxially to each other by a fitting type coupling 4, and the driving force of the electric motor 3 taken out to the motor shaft 30 is transmitted to the pump shaft 10 via the coupling 4, and the pump body 1 is driven.

The pump body 1 has a drive gear 12 and a driven gear 13 meshed with each other in a hollow portion (gear chamber) having an oval cross section formed in a housing 11, and is provided on one side of these meshed portions. The hydraulic oil in the suction chamber 18 (see FIG. 2) is conveyed while being confined between the respective teeth and the inner peripheral surface of the cavity by the rotation of both gears, and is pressurized. It is configured as a known gear pump that discharges into a provided discharge chamber (not shown). Note that the driven gear 13 in FIG. 1 is illustrated in a state where it is partially overlapped with the drive gear 12 on the near side of the drawing.

The drive gear 12 and the driven gear 13 are supported by a pair of side plates 14 and 14 fitted into the hollow portion of the housing 11 from both sides so as to be rotatable while maintaining the above-mentioned meshing state. In the pump body 1 configured as described above, one end surface of the housing 11 abuts against the support surface of the support bracket 2, and a plurality of the pump bodies 1 are arranged in the circumferential direction together with the end plate 15 stacked on the other end surface (in the drawing). Are fixed to the end surface of the support bracket 2 together by four fixing bolts 16, 16,....

The pump shaft 10 is fitted to the shaft center of the drive gear 12, penetrates one side plate 14 and protrudes toward the support bracket 2, and is connected to the motor shaft 30 of the electric motor 3 by the cup. The pump operation by the pump main body 1 is performed by transmitting the rotation of the electric motor 3 to the drive gear 12 via the motor shaft 30, the coupling 4 and the pump shaft 10. However, this is caused by rotation in the inner cavity of the housing 11 together with the driven gear 13 meshing therewith.

As described above, the support bracket 2 for supporting the pump body 1 is provided with a bottomed cylindrical tank cylinder 5 made of a thin plate material around the outer periphery of the mounting-side end face of the pump body 1. The opening side peripheral edge is fitted to the formed spigot portion, and is attached so as to surround the outside of the pump main body 1. A reserve tank T for storing hydraulic oil inside the tank cylinder 5 is formed.

As shown in FIG. 2, the tank cylinder 5 has a return port which penetrates the peripheral wall and opens to the inner surface at one location in the circumferential direction. It is connected to an oil feed destination (not shown) via a projecting return pipe 50, and the return oil from the oil feed destination is returned to the inside of the reserve tank T via the return pipe 50.

In the pump device according to the present invention, the fluid distribution 6 is provided inside the tank cylinder 5 so as to face the return port.
Is installed. FIG. 3 is a perspective view illustrating a configuration of the fluid dividing device 6. As shown in the figure, the fluid distribution 6 is provided with a bottom plate 60 in the form of a partial circle having a curved shape corresponding to the inner surface of the tank cylinder 5.
Is a synthetic resin member formed as a shallow bottom box having a curved bottom, with a flange plate 61 of a predetermined width projecting outwardly of the curved circle around the periphery of.

At a substantially central portion of the bottom plate 60 in the bending direction, a diversion projection 62 projecting in a triangular shape outwardly from the curved circle is provided, and the diversion projection 62 is divided by the diversion projection 62. A plurality of (six in the figure) return holes 63 penetrating the bottom plate 60 from front to back are formed in one side half. Further, the other half of the bottom plate 60 separated by the diversion projection 62 is communicated to the outside by a lead-out pipe 64 connected to a substantially central portion of the flange plate 61 at the end thereof.

A flange plate 61 for bordering one curved edge of the bottom plate 60
A plurality (three in the figure) of support projections 65 are projected from the outside in a direction substantially orthogonal to this, and the flange 61 is provided with the support projections 65, 65. A through-hole 66 is formed to penetrate a position that does not interfere with each of the above. The opening of the through-hole 66 to the inside of the flange plate 61 is covered by an opposing baffle plate 67 at an appropriate distance.

As shown in FIG. 2, the flow dividing fluid 6 configured as described above is directed along the inner circumference of the tank cylinder 5 with its opening side facing outward, and the flow dividing projection 62 is formed at the base end of the return pipe 50. Is positioned and fixed in the circumferential direction so as to face the inside of the return port that opens to the outside.

In order to fix the fluid dividing device 6, the support projections 65, 65,... Are respectively inserted into special support holes 20, 20,. (Indicated by a dashed line). As shown in FIG. 3, each of the support projections 65 is provided with a notch on a part of the peripheral surface of a cylindrical body having an outer diameter slightly larger than the inner diameter of the support holes 20, 20,. The support of the fluid dividing device 6 is facilitated by pushing such support protrusions 65 into the respective support holes 20, 20,... While deforming the respective notches. Moreover, it can be realized stably.

As described above, the return oil from the oil supply destination flowing back through the return pipe 50 due to the attachment of the dividing fluid 6 is:
As shown by the arrow in FIG. 2, the return flow diverted to one side (the right side in FIG. 2) by colliding with the diversion protrusion 62 facing the return opening opening at the base of the return pipe 50, and diverted to one side (the right side in FIG. The oil is returned into the tank cylinder 5 through each of the return holes 63 formed in the bottom plate 60 on the same side. The return oil diverted to the other side (the left side in FIG. 2) is supplied to the inner surface of the tank cylinder 5 and the bottom plate of the divided fluid 6.
Flows along an annular space between the flange plate 61 and the flange plate 61 at the same end.
Is led out through a lead-out pipe 64 connected to the outside.

As shown in FIG. 2, a suction pipe 17 communicating with a suction chamber 18 inside the housing 11 is connected to the pump body 1 inside the tank cylinder 5. The suction pipe 17 has a housing
11 is a large-diameter rubber pipe or resin pipe that protrudes radially and is curved along the inner surface of the tank cylinder 5, and the leading end of the outlet pipe 64 opens in the circumferential direction of the tank cylinder 5. It is inserted into the suction pipe 17.

The return oil that collides with the diversion protrusion 62 and is diverted to the left side in FIG.
The pump body 1 is drawn out into the reservoir tank T together with hydraulic oil introduced from the inside of the reserve tank T through the remaining opening of the suction pipe 17.
The drive gear 12 is introduced into the suction chamber 18 inside, as described above.
And the pressure of the suction chamber 18 is increased by the rotation of the driven gear 13.
Is discharged to a discharge chamber (not shown) arranged on the other side.

A support bracket 2 for supporting the pump body 1 and the tank cylinder 5 has a damper chamber 21 having a predetermined internal volume.
However, it is configured as an annular chamber surrounding the outside of the connection between the pump shaft 10 and the motor shaft 30, and the discharge chamber of the pump main body 1 communicates with the damper chamber 21. As shown in FIG. 2, a discharge seat 22 protrudes from one portion of the outer periphery of the support bracket 2, and a discharge port 23 opened at the center of the discharge seat 22 is connected to the damper inside the support bracket 2. It is connected to the room 21.

With the above construction, the oil discharged from the pump body 1 is once introduced into the damper chamber 21 and sent out to the oil feed destination (not shown) through the discharge port 23. At this time, the damper chamber 21 functions to absorb the pulsating component of the discharge oil introduced from the discharge chamber of the pump body 1 and reduce the pulsation of the oil delivered from the discharge port. The pulsating component of the discharge oil from the pump body 1 corresponds to the product of the number of rotations of the drive gear 12 and the driven gear 13 as a rotor and the number of teeth of the drive gear 12 and the driven gear 13 that is the number of discharges per rotation. The pulsation can be effectively absorbed by setting the internal volume of the damper chamber 21 based on the product.

The damper chamber 21 communicates with a through hole 66 formed in the fluid divider 6 via a relief valve (not shown). If an excessive pressure rise occurs in the damper chamber 21, The rising pressure is released by the operation of the relief valve through the through hole 66 to the inside of the fluid divider 6, and further released through the return holes 63, 63... To the inside of the tank cylinder 5.

During the operation of the pump as described above, the working oil stored in the reserve tank T is filled in the suction chamber 18 with the suction pipe 17.
A part of the return oil which is sucked in through the return pipe and returned from the oil supply destination through the return pipe 50 is diverted by the action of the dividing fluid 6 and introduced through the outlet pipe 64 with a predetermined pressure and speed. Is done.

While the pump body 1 is stopped, the hydraulic oil in the reserve tank T is stagnant without speed, and immediately after the pump body 1 is started in this state, the reserve tank T The suction state at the opening of the suction pipe 17 into the inside becomes unstable, cavitation is likely to occur, and unpleasant cavitation noise may be generated. In the pump device according to the present invention, the return oil from the oil supply destination is fed into the suction pipe 17 via the outlet pipe 64, and the pump body 1
Immediately after startup, a flow of hydraulic oil is generated in the suction pipe 17, and the action of this flow promotes suction from the reserve tank T. As a result, the suction state is stabilized and cavitation is effectively generated. Can be suppressed.

In the above embodiment, a description has been given of the pump device in which the reserve tank T for storing the hydraulic oil is provided integrally with the outside of the pump main body 1. However, the reserve tank T and the pump main body 1 are separately provided. The present invention is also applicable to a pump device provided. The diversion means for diverting a part of the return oil to the reserve tank T to the suction side of the pump main body 1 is not limited to the diversion fluid 6 shown in the embodiment, but may have another configuration.

In the above embodiment, a pump device mounted on an automobile for obtaining hydraulic oil for a hydraulic operating device such as a power steering device and an automatic transmission has been described. It goes without saying that the present invention can be applied to a pump device used for purposes other than automobiles, and further to a pump device for handling liquids other than oil.

[0038]

As described in detail above, in the pump device according to the present invention, a part of the hydraulic fluid returning from the liquid supply destination to the reserve tank is divided by the diversion means arranged facing the return port. Since the pump is returned to the suction side of the pump body, the flow on the suction side can be stabilized in the transitional period immediately after the start of the pump body, the occurrence of cavitation can be suppressed, and operation at high speed to prevent pulsation on the discharge side Even when the cavitation sound is generated, the generation of high-frequency cavitation sound can be effectively reduced, and when used for automobiles, the driver who listens to the cavitation sound does not feel useless anxiety.

Further, since the bottomed cylindrical body is supported by the support bracket of the pump body and the reserve tank is integrally formed, the pump device capable of reducing the cavitation noise and operating quietly can be made compact. .

Further, since the flow dividing means is constituted by the plate material attached to the return port opened on the peripheral surface of the cylindrical body constituting the reserve tank, the generation of cavitation noise can be effectively prevented by a simple structure. The present invention has excellent effects, for example, a miniaturized pump device capable of quiet operation can be realized.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a pump device according to the present invention, which is cut away.

FIG. 2 is a cross-sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view showing a configuration of a fluid separation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump main body 2 Support bracket 3 Electric motor 5 Tank cylinder 6 Divided fluid 12 Drive gear 13 Follower gear 17 Suction pipe 50 Return pipe 60 Bottom plate 62 Divided projection 64 Outgoing pipe T Reserve tank

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F04C 15/00 F04B 21/00 H 15/04 U F term (reference) 3H041 AA02 BB02 CC11 CC17 DD01 DD12 DD20 DD34 DD38 3H044 AA02 BB01 BB02 BB05 BB08 CC11 CC14 CC16 DD01 DD10 DD12 DD24 DD28 3H071 AA03 BB02 CC21 CC24 CC25 CC31 CC32 DD31 DD32 DD37 DD72 DD74

Claims (3)

[Claims] 1. A pump in which a working fluid inside a reserve tank having a return port from a liquid sending destination is sucked into a pump main body through a suction port opened in the reserve tank, and pressure is increased in the pump main body. In the pump device configured to return and return the liquid from the liquid supply destination through the return port to the inside of the reserve tank while circulating the liquid, the liquid is disposed inside the reserve tank, and the liquid is supplied from the return port. A pumping device comprising a flow dividing means for diverting a part of the return liquid and guiding the liquid to the suction port. 2. The pump device according to claim 1, wherein the reserve tank is configured by supporting a bottomed cylindrical body surrounding the outside of the pump main body on a support bracket of the pump main body. 3. The pump device according to claim 2, wherein the flow dividing means is formed of a plate material which is attached to a return port opened on a peripheral surface of the cylindrical body and has a convex portion crossing the return port. .