JP6065632B2 - Reservoir tank - Google Patents

Description

  The present invention relates to a pressurized reservoir tank that is used in, for example, a hydraulic power steering apparatus and accumulates and filters hydraulic fluid.

  Conventionally, as this type of reservoir tank, for example, a reservoir tank described in Patent Document 1 is known. FIG. 9 shows the structure of the reservoir tank described in this document. The reservoir tank 101 is a pressurized reservoir tank that includes a baffle 104 that pressurizes hydraulic oil flowing from the inflow pipe 102 and easily passes through a filter 103 that filters the hydraulic oil.

  The hydraulic oil flowing in from the inflow pipe 102 is pumped into the pressurizing chamber 107 of the baffle 104, whereby the flow velocity decreases, and the flow velocity energy is converted into pressure energy and pressurized. And the inside of the pressurization chamber 107 becomes a positive pressure. On the other hand, since the funnel chamber 108 of the funnel portion 106 is connected to the suction side of the oil pump (not shown) via the outflow pipe 105, the suction force of the oil pump acts and becomes negative pressure.

  As a result, the hydraulic oil in the tank main body 109 faces the positive pressure and the negative pressure close to each other with the filter 103 interposed therebetween. Then, by generating such a pressure difference, it becomes possible to smoothly pass through the filter 103 even if the operating oil is in a highly viscous state. Therefore, since the hydraulic oil flows smoothly according to the suction force of the oil pump, it is possible to suppress the occurrence of cavitation due to poor suction of the oil pump even at low temperatures where the viscosity of the hydraulic oil is high.

Japanese Patent No. 2001-138934

  When an automobile is driven in an area with many unpaved roads such as an emerging country, a lot of sand adheres to the outer periphery of the reservoir tank 101, and the sand flows into the tank main body 109 through a passage not shown in the cap 110. This sand passes through the filter 103 and flows into the oil pump (not shown) through the outflow pipe 105, which may damage the cam surface of the oil pump.

  If the filter 103 is made fine enough to capture sand, the flow resistance of the filter 103 increases when the viscosity of the hydraulic oil becomes high at low temperatures, and a necessary flow rate cannot be secured for the oil pump. There was a problem.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a reservoir tank that can prevent sand from flowing out to an outlet and can secure a necessary flow rate at a low temperature. That is.

  A reservoir tank for solving the above problems includes an oil inlet for injecting hydraulic oil, an outlet for flowing out the hydraulic oil, a tank body formed with an inlet for inflow of hydraulic oil, and a cap for closing the oil inlet. In the reservoir tank having a filter disposed between the outlet and the inlet, and a baffle having a through hole inside, one end opened to the inlet and the other end opened to the filter, The filter includes a pressurization chamber filter that communicates with the through-hole and a pressurization chamber filter that does not communicate with the through-hole, and the pressurization chamber filter has a coarseness capable of removing sand, and the pressurization chamber The filter is coarser than the pressurized outdoor filter and has a coarseness capable of removing sludge in the hydraulic oil.

  According to the present invention, the sludge in the hydraulic oil can be captured by the pressurizing chamber filter, and the necessary flow rate can be secured at a low temperature, and the sand can be captured by the pressurizing chamber filter, so that the sand is prevented from flowing out from the outlet. can do.

1 is a partial cross-sectional side view showing a structure of a reservoir tank according to an embodiment of the present invention. It is sectional drawing which showed the structure of the reservoir tank concerning one Embodiment of this invention. FIG. 3 is an enlarged cross-sectional view of a region Z in FIG. 2 according to an embodiment of the present invention. It is a top view which shows schematic structure of the intermediate member provided in the reservoir tank concerning one Embodiment of this invention. It is a bottom view of the reservoir tank concerning one embodiment of the present invention. It is the top view which carried out the cross section of the intermediate member vicinity of the reservoir tank concerning one Embodiment of this invention. It is a flow analysis figure at the time of the low temperature of the hydraulic fluid in the reservoir tank concerning one Embodiment of this invention. It is a flow analysis figure at the time of the high temperature of the hydraulic fluid in the reservoir tank concerning one Embodiment of this invention. It is sectional drawing which showed the structure of the conventional reservoir tank.

  An embodiment as an example of the present invention will be described with reference to FIGS. 1 to 6. 1 is a partially sectional side view showing the structure of the reservoir tank, FIG. 2 is a sectional view showing the structure of the reservoir tank, FIG. 3 is an enlarged sectional view of a region Z in FIG. 2, and FIG. FIG. 5 is a bottom view of the reservoir tank, FIG. 6 is a top view of the reservoir tank taken along the intermediate member, and FIG. 7 is an operation in the reservoir tank. FIG. 8 is a flow analysis diagram of the hydraulic oil in the reservoir tank at a high temperature.

  As shown in FIG. 1 and FIG. 2, the reservoir tank 1 is disposed in the engine room of the automobile, and the inflow pipe 2 is connected to the discharge side of the power assist mechanism portion which is an actuator by piping such as a rubber hose and a metal tube. The outflow pipe 7 is connected to the suction side of an oil pump that is a hydraulic source. The reservoir tank 1 has a function of accumulating hydraulic oil flowing from the inflow pipe 2 and includes a filter 3 that filters the hydraulic oil. The reservoir tank 1 has an oil supply port 5c for injecting hydraulic oil, and the oil supply port 5c is closed by an oil cap 16 while maintaining a slight atmospheric communication state. The reservoir tank 1 is a pressurization type reservoir tank provided with a baffle 4 that pressurizes hydraulic oil flowing in from the inflow pipe 2 and easily passes through the filter 3.

  The reservoir tank 1 has an inflow pipe 2, a tank portion 5 for accumulating hydraulic oil, a baffle 4 for pressurizing the hydraulic fluid, an intermediate member 6 provided with a filter 3, and a funnel portion 8 having an outflow pipe 7. And. The reservoir tank 1 is integrally configured by stacking the tank portion 5, the intermediate member 6, and the funnel portion 8 in this order and welding them together. The baffle 4 is disposed in the tank portion 5 and connected to the inflow pipe 2.

  The tank portion 5 is a molded body made of, for example, a synthetic resin having a substantially cylindrical shape. An oil injection port 5c for injecting oil is formed at the upper end portion, and a flange portion 5a protruding in a collar shape is formed at the lower end portion. ing. On the lower surface of the flange portion 5a, there is provided an annularly welded portion (not shown) used for welding. An inflow port 5b is formed at the lower end of the tank unit 5, and the inflow pipe 2 leading to the inflow port 5b is welded. In addition, this inflow pipe 2 may be integrally molded with the tank part 5 by injection molding.

  As shown in FIG. 4, the intermediate member 6 is a molded body made of, for example, synthetic resin having a substantially ring shape, and has a ring portion 3 c on the outer periphery thereof and a partition wall 10 on the inner periphery thereof. The inner periphery of the intermediate member 6 is a circular hole 3a, and a plurality of eyebrows-shaped eyebrows 3b are arranged around the periphery of the circular hole 3a. The circular hole 3 a and the eyebrow hole 3 b are separated by a cylindrical partition wall 10, and the partition wall 10 extends to a position in contact with the baffle 4. A filter 3 made of nylon, for example, is provided in the circular hole 3a and the eyebrow hole 3b. In addition, this filter 3 is for filtering hydraulic fluid, The material and the attachment method to the intermediate member 6 are arbitrary. In addition, welded portions (not shown) used for welding are provided on the peripheral edges of the upper surface and the lower surface of the ring portion 3c.

  The filter 3 includes a pressurizing chamber filter 3d provided in the circular hole 3a and a pressurizing outdoor filter 3e provided in the eyebrow mold hole 3b. The pressurizing chamber filter 3d has a function of filtering the hydraulic oil when flowing out from the pressurizing chamber 11 of the baffle 4 to the funnel chamber 12 of the funnel portion 8, and captures sludge in the hydraulic oil. The pressurized outdoor filter 3e has a function of filtering the hydraulic oil when it flows out from the tank unit 5 to the funnel chamber 12, and captures sand that has flowed into the tank unit 5 from the outside through a communication passage described later of the oil cap 16. To do. Since sand has a smaller particle size than the sludge in the hydraulic oil, the coarseness of the pressurization chamber filter 3e is finer than the coarseness of the pressurization chamber filter 3d. The pressurizing chamber filter 3d and the pressurizing chamber filter 3e have a mesh formed by injection molding.

  As shown in FIGS. 1 to 3, the baffle 4 has a through hole 4 a formed therein, and one end of the through hole 4 a communicates with the inflow port 5 b of the tank unit 5, and the other end of the through hole 4 a is the baffle 4. It communicates with the recess 9. The recess 9 has an inner diameter substantially the same as the outer diameter of the circular hole 3a of the filter 3 (the inner diameter of the wall 10). The baffle 4 is attached to the tank unit 5 at a position where one end of the through hole 4 a communicates with the inlet 5 b of the tank unit 5. A pressurizing chamber 11 is defined by the recess 9 of the baffle 4, the partition wall 10 of the intermediate member, and the filter 3. The pressurizing chamber 11 communicates with the inflow pipe 2 through the inlet 5b through a through hole 4a formed in the baffle 4 so that substantially the entire amount of hydraulic oil flowing in from the inflow pipe 2 flows into the pressurizing chamber 11. It has become.

  Further, as shown in FIG. 6, the baffle 4 has a collar-like baffle flange portion 15 extending in four directions toward the inner peripheral surface of the tank portion 5, and between the tank portion 5 and the intermediate member 6. They are arranged in a sandwiched manner. On the upper wall of the baffle 4 on the oil filling port 5c side, an air vent hole 4c that communicates in the vertical direction between the space in the tank portion 5 and the through hole 4a is formed. The air vent hole 4c is closed by a pressure rod 16a (described later) of the oil cap 16.

  The funnel portion 8 is, for example, a synthetic resin molded body having a substantially funnel shape as shown in FIGS. 2 and 6, and the outflow pipe 7 is integrally formed with the funnel portion 8. The inflow pipe 2 and the baffle 4 may be provided separately and integrated by welding or the like.

  A bottomed cylindrical dish-like portion 13 is provided on the upper portion of the funnel portion 8. An outlet 13a is formed in the dish-like portion 13, and the outflow pipe 7 is integrally connected to the outlet 13a. The outflow pipe 7 extends in the radial direction of the reservoir tank 1. The dish-like part 13 and the outflow pipe 7 are connected so that the inside of the dish-like part 13 and the inside of the outflow pipe 7 communicate with each other, and the connecting part is formed in a substantially funnel shape. The upper end of the dish-like portion 13 is provided with a welded portion (not shown) that is welded to the intermediate member 6. The tank portion 5 and the funnel portion 8 are assembled so as to be rotatable with the intermediate member 6 interposed therebetween in the manufacturing process, and an angle formed by a later-described through hole 4a and the outflow pipe 7 is determined to be a predetermined acute angle. And then welded.

  A funnel chamber 12 defined by the filter 3, the dish-shaped portion 13, and the outflow pipe 7 is formed inside the funnel portion 8. The funnel chamber 12 is disposed immediately below the filter 3, and hydraulic oil that has passed through the filter 3 is guided to the funnel chamber 12. And the dish-shaped part 13 is formed so that the distance between the filter surface on the funnel chamber side of the filter 3 and the bottom surface of the dish-shaped part 13 is separated by a predetermined distance, thereby forming a space having a predetermined height α. Has been. In the present embodiment, the height α of the space is set to be approximately the same as the height β of the pressurizing chamber 11.

  The hydraulic oil flowing along the through hole 4a hits the back wall portion 4b of the baffle 4 so that the flow direction is changed to the filter 3 side. Below the back wall 4 b of the baffle 4 is a connecting portion between the dish-like portion 13 and the outflow pipe 7, and a curved start end (curved end 14) that curves toward the outflow pipe 7 is provided. It has been. The curved end portion 14 is formed at a position where the hydraulic oil whose flow direction has been changed by the back wall portion 4 b of the baffle 4 is hit. That is, the hydraulic oil flowing along the arrow f2 shown in FIG. 3 is split by the curved end portion 14 into a flow toward the outflow pipe 7 (main flow f3) and a flow toward the tank portion 5 (branch flow f4). As shown in FIG. 5, the curved end portion 14 is provided with a semicircular end portion in the illustrated manner when the reservoir tank 1 is viewed from the lower surface.

  The wall surface of the back wall portion 4b to which the hydraulic oil flows is formed perpendicular to the plane of the filter 3, and the outlet pipe 7 has a predetermined acute angle with the through hole 4a. It is arranged. Here, the predetermined acute angle means that the arrangement position of the outflow pipe 7 is an angle from 0 degrees to 90 degrees in the positive direction around the axial direction of the through hole 4a, or from 0 degrees to 90 degrees in the negative direction. An angle at the position of the range. The positive direction is the clockwise direction in FIG. 6, and the negative direction is the counterclockwise direction in FIG.

  The tank unit 5 and the funnel unit 8 constitute a tank body that accumulates hydraulic oil. The tank body has an oil inlet 5c, an inlet 5b, and an outlet 13a.

  An oil cap 16 is detachably attached to the oil filling port 5c, and a communication passage (not shown) that connects the inside of the tank body and the outside is formed in the oil cap 16. The air in the tank body flows out to the outside through the communication passage. A pressure rod 16a extends in the vertical direction below the oil cap 16, and the air vent hole 4c of the baffle 4 is closed by the pressure rod 16a.

With such a configuration, the reservoir tank 1 operates as follows.
First, the hydraulic oil flowing in from the inflow pipe 2 is pumped into the pressurizing chamber 11 of the baffle 4 to reduce the flow velocity, and the flow velocity energy is converted into pressure energy to be pressurized. And the inside of the pressurization chamber 11 becomes a positive pressure. On the other hand, since the funnel chamber 12 of the funnel portion 8 is connected to the suction side of the oil pump via the outflow pipe 7, the suction force of the oil pump acts and becomes negative pressure.

  As a result, the hydraulic oil in the reservoir tank 1 has a positive pressure (pressurizing chamber 11) and a negative pressure (funnel chamber 12) facing each other with the filter 3 in between. As a result of such a pressure difference, as shown in FIG. 8, even if the hydraulic oil is in a highly viscous state, it can smoothly pass through the pressurizing chamber filter 3d.

  Next, with reference to FIG. 7 and FIG. 8, experimental results of flow analysis of the reservoir tank 1 having such a configuration at a low temperature (for example, −30 ° C.) and a high temperature (for example, 80 ° C.) will be described.

  As shown in FIG. 7 for the flow analysis of the hydraulic oil at low temperature, the hydraulic oil generally has high viscosity and low fluidity at low temperatures. And is sucked into the oil pump through the outflow pipe 7 of the funnel 8. That is, the hydraulic oil flows along the arrow f1 (see also FIG. 2). By being pressurized by the baffle 4 in this way, there is no fluid flow failure. Further, since the outflow pipe 7 is arranged so as to form a predetermined acute angle with respect to the through hole 4a, the hydraulic oil flows smoothly from the through hole 4a to the outflow pipe 7. For this reason, poor flow of hydraulic oil can be eliminated, and the occurrence of cavitation of the oil pump can be suppressed. In addition, part of the hydraulic oil that has passed through the filter 3 from the baffle 4 (pressurizing chamber 11) rebounds at the dish-like portion 13 near the curved end portion 14, and the flow from the funnel portion 8 to the tank portion 5 can be made with a small amount of flow. Since the oil pump can draw the oil from the tank part 5 to the funnel part 8, the hydraulic oil accumulated in the tank part 5 circulates (flows), and the air mixed in the hydraulic oil is easily released. .

  As shown in FIG. 8 for the flow analysis of the hydraulic oil at a high temperature, the hydraulic oil generally has a low oil viscosity and a high fluidity at a high temperature. And since the wall surface of the back wall part 4b to which the flow of hydraulic oil hits is an angle perpendicular | vertical with respect to the said filter surface, after the flow of hydraulic oil hits the back wall part 4b of the baffle 4, it is filter 3d. Is passed through vigorously and hits the curved end 14. The flow of the hydraulic oil is divided into two flows at the curved end portion 14. That is, the flow is changed so that the hydraulic oil rebounds at the flow ("main flow f3") flowing to the outflow pipe 7 side (oil pump side) and the dish-like portion 13 near the curved end portion 14, and the predetermined height This is a flow (“branch flow f4”) that flows through the space having a length α to the tank unit 5.

  As described above, the branch flow f4 is generated, so that the hydraulic oil flows into the tank portion 5 at a high temperature. In general, the tank portion 5 of the reservoir tank 1 is open to the atmosphere. And even if air is mixed in hydraulic fluid by operating oil flowing into tank part 5, it will be discharged outside through an air hole.

The present invention is not limited to these embodiments, and can of course be implemented in various modes without departing from the gist of the present invention.
In the above embodiment, the general term of the pressurizing chamber filter 3d and the pressurizing outdoor filter 3e is a filter, but the general term including the pressurizing chamber filter 3d, the pressurizing outdoor filter 3e, and the intermediate member 6 may be a filter. .

  In the above embodiment, the filter 3 made of nylon is used. As another embodiment, a metal filter having a mesh formed of a wire may be used. In this case, a metal filter is set in an injection mold and molten resin is poured into the intermediate member. In this way, the intermediate member and the filter are integrated.

1: reservoir tank, 2: inflow pipe, 3: filter, 3d: pressurization chamber filter, 3e: pressurization chamber filter, 4: baffle, 4a: through hole, 5: tank section (tank body), 5b: inflow port 5c: Oil filler port, 7: Outflow pipe, 8: Funnel part (tank body), 13a: Outlet port, 16: Oil cap

Claims (1)

An oil injection port for injecting hydraulic oil, an outlet for discharging hydraulic oil, a tank body formed with an inlet for inflow of hydraulic oil, a cap for closing the oil injection port, and an arrangement between the outlet and the inlet And a baffle having one end opened to the inlet and the other end opened to the filter. The reservoir is a pressurizing chamber that communicates with the through hole. A filter and a pressurized outdoor filter that does not communicate with the through hole, and the pressurized outdoor filter has a coarseness capable of removing sand, and the pressurized chamber filter is coarser than the pressurized outdoor filter. A reservoir tank characterized by being coarse and having a coarseness capable of removing sludge in hydraulic fluid.

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