JP2020131886A - Liquid storage structure and working fluid storage structure of hydraulic hybrid vehicle - Google Patents

Abstract

To collect air bubbles mixed into a liquid in a tank effectively.SOLUTION: A liquid storage structure includes: a tank 60 which stores a liquid; a feed passage 53 which sends the liquid from the tank 60; a return passage 52 which returns the liquid to the tank 60; a float member 70 which floats in the liquid in the tank 60; and a partition member 81 in which one end is rotatably connected to the float member 70 and the other end is formed as a free end which contacts with a bottom part of the tank 60 and which partitions the liquid in the tank 60 into the return passage 52 side and the feed passage 53 side. The partition member 81 is formed with holes that may collect air bubbles in the liquid while allowing circulation.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a liquid storage structure and a hydraulic oil storage structure of a hydraulic hybrid vehicle.

Conventionally, there is known a hydraulic hybrid vehicle in which an engine is connected to a drive wheel via a power transmission device including a clutch device, a transmission and the like, and a pump and a motor operating as a motor are connected to the power transmission device. (See, for example, Patent Document 1 and the like).

In this type of hydraulic hybrid vehicle, the pump motor is operated as a motor by the hydraulic pressure accumulated in the accumulator at the time of starting or accelerating to transmit power to the drive wheels, while the power transmitted back from the drive wheels during braking. It is configured to operate the pump motor as a pump to accumulate pressure in the accumulator.

Japanese Unexamined Patent Publication No. 2013-189805

In the above hydraulic hybrid vehicle, for example, when braking by operating a pump / motor as a pump, or depending on the shape of the road surface on which the vehicle travels, the oil level of the hydraulic oil in the oil tank fluctuates greatly, so that the hydraulic oil Bubbles may be generated inside. If such air bubbles are mixed with the hydraulic oil supplied to the pump motor, it may cause the pump motor to malfunction. Further, if a circuit or the like for removing air bubbles in the hydraulic oil is provided separately from the oil tank, the size of the entire device may be increased.

The technique of the present disclosure aims to effectively collect air bubbles mixed in a liquid in a tank with a simple structure.

The liquid storage structure of the present disclosure includes a tank for storing liquid, a feed flow path for sending out the liquid from the tank, a return flow path for returning the liquid to the tank, and a float floating on the liquid in the tank. One end of the member is rotatably connected to the float member, and the other end is a free end that contacts the bottom of the tank, so that the liquid in the tank is rotatably connected to the return flow path side and the feed flow path side. A plurality of partition members capable of collecting air bubbles contained in the liquid while allowing the liquid to flow from the return flow path side to the feed flow path side. It is characterized in that a hole is formed.

Further, the partition member changes its posture while rotating with one end as a fulcrum in conjunction with the drop of the float member accompanying the drop of the liquid level in the tank, whereby the liquid in the tank. Is preferable to always partition the return flow path side and the feed flow path side.

Further, it is preferable that the float member is formed in the same shape as the cross-sectional shape of the tank and covers the entire liquid surface of the liquid in the tank.

Further, the partition member is preferably formed of a net-like member having a plurality of small holes.

Further, as the partition member, a first partition member on the feed flow path side and a second partition member on the return flow path side are provided, and the hole of the second partition member is larger than the hole of the first partition member. It is preferably formed with a small diameter.

Further, the liquid storage structure is a hydraulic oil storage structure of a hydraulic hybrid vehicle, and the hydraulic hybrid vehicle operates as a motor with a pressure accumulator and hydraulic oil supplied from the pressure accumulator to transmit power to drive wheels. At the same time, it is provided with a pump motor that operates as a pump by the power transmitted from the drive wheels to accumulate the accumulator, and when the pump motor operates as a motor, the pump motor operates as a motor through the return flow path. When the hydraulic oil is returned to the tank and the pump motor operates as a pump, the hydraulic oil is discharged from the tank through the feed flow path.

According to the technique of the present disclosure, it is possible to effectively collect air bubbles mixed in the liquid in the tank with a simple structure.

It is a schematic overall block diagram which shows the hydraulic hybrid vehicle which concerns on this embodiment. (A) is a schematic diagram for explaining the "regeneration mode" of the regenerative device according to the present embodiment, and (B) is a schematic diagram for explaining the "drive mode" of the regenerative device. It is a schematic vertical sectional view which shows the oil tank, the float member, and the collection mechanism which concerns on 1st Embodiment. FIG. 4 is a schematic vertical sectional view illustrating a state in which the oil level has dropped. It is a schematic vertical sectional view which shows the oil tank, the float member, and the collection mechanism which concerns on 2nd Embodiment. FIG. 5 is a schematic vertical sectional view illustrating a state in which the oil level has dropped. It is a schematic vertical sectional view which shows the oil tank, the float member, and the collection mechanism which concerns on another embodiment.

Hereinafter, the liquid storage structure and the hydraulic oil storage structure of the hydraulic hybrid vehicle according to the present embodiment will be described with reference to the accompanying drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

[overall structure]
FIG. 1 is a schematic overall configuration diagram showing a hydraulic hybrid vehicle 1 according to the present embodiment.

As shown in FIG. 1, the hydraulic hybrid vehicle 1 is equipped with an engine 10 as an example of a driving force source. The input shaft 21 of the transmission 20 is connected to the crankshaft 11 of the engine 10 via the clutch device 12. The output shaft 22 of the transmission 20 is connected to the left and right drive wheels 27 and 28 via the propeller shaft 13, the differential gear device 24, and the left and right drive shafts 25 and 26, respectively. The hydraulic hybrid vehicle 1 is not limited to the rear-wheel drive vehicle shown in the illustrated example, and may be a front-wheel drive vehicle or a four-wheel drive vehicle.

The transmission 20 is provided with a power take-off (PTO) device 30 capable of transmitting power to the output shaft 22 or taking out power from the output shaft 22. The pump motor 41 of the regenerative device 40 is connected to the PTO shaft 31 of the PTO device 30. The PTO device 30 may be provided on a flywheel (not shown) that can rotate integrally with the crankshaft 11 of the engine 10. Further, the pump motor 41 of the regenerative device 40 may be interposed between the clutch device 12 and the transmission 20.

The regeneration device 40 includes a pump motor 41 connected to a PTO shaft 31, an accumulator 42 (accumulator) for accumulating hydraulic energy, and hydraulic pressure for supplying and discharging hydraulic oil to the pump motor 41 and the accumulator 42. It includes a circuit 50 and an oil tank 60 for storing hydraulic oil.

The hydraulic circuit 50 is composed of a supply oil passage 51 connecting the pump motor 41 and the accumulator 42, a return oil passage 52 (return flow path) for returning hydraulic oil from the pump motor 41 to the oil tank 60, and an oil tank 60. It is provided with a suction oil passage 53 (feed passage) for feeding hydraulic oil to the pump motor 41. The downstream end of the suction oil passage 53 joins a predetermined portion of the return oil passage 52. The suction oil passage 53 is provided with a check valve 54 that regulates the flow of hydraulic oil in the opposite direction while allowing the flow of hydraulic oil from the oil tank 60 side to the pump motor 41 side.

The regenerative device 40 is set to a "regenerative mode" in which the pump motor 41 is operated as a pump by the power transmitted back from the drive wheels 27 and 28 via the PTO device 30 and the like when the hydraulic hybrid vehicle 1 is braked. .. Further, the regenerative device 40 has a "drive mode" in which the pump motor 41 is driven as a motor and power is transmitted from the PTO device 30 or the like to the drive wheels 27 and 28 when the hydraulic hybrid vehicle 1 is started or accelerated. It is said that.

Specifically, as shown in FIG. 2A, in the "regenerative mode" in which the pump motor 41 operates as a pump, the hydraulic oil sent out from the oil tank 60 through the suction oil passage 53 is pumped. It is pressurized and pumped to the supply oil passage 51 by the motor 41, and is stored as hydraulic energy in the accumulator 42. On the other hand, in the "drive mode" shown in FIG. 2B, the pump motor 41 operates as a motor by supplying the hydraulic oil pumped from the accumulator 42 through the supply oil passage 51 to the pump motor 41. To do. The hydraulic oil supplied to the pump motor 41 is returned to the oil tank 60 via the return oil passage 52.

In the present embodiment, the oil tank 60 is provided with a float member 70 that suppresses fluctuations in the oil level of the hydraulic oil and a collection mechanism 80 that collects and removes air bubbles in the hydraulic oil. The details of the float member 70 and the collection mechanism 80 will be described below.

[First Embodiment]
FIG. 3 is a schematic vertical sectional view showing an oil tank 60, a float member 70, and a collection mechanism 80 according to the first embodiment.

The oil tank 60 is, for example, a box-shaped body having six surfaces closed, and hydraulic oil is stored inside the oil tank 60. A through hole 61A is provided in the upper plate portion 61 of the oil tank 60, and a return oil passage 52 is fitted into the through hole 61A. The through hole 61A and the return oil passage 52 are preferably arranged adjacent to the first side plate portion 62 of the oil tank 60.

A through hole 63A is provided in the second side plate portion 63 facing the first side plate portion 62 of the hydraulic tank 60, and the suction oil passage 53 is fitted into the through hole 63A. The through hole 63A and the suction oil passage 53 are preferably arranged adjacent to the bottom plate portion 63 side of the oil tank 60. In the hydraulic tank 60, the outlet portion (lower end portion) of the return oil passage 52 is preferably provided so as to be located above the inlet portion of the suction oil passage 53.

The float member 70 is a plate-shaped member that floats on the oil surface of the hydraulic oil in the hydraulic tank 60. The material of the float member 70 is not particularly limited as long as it has a lighter specific gravity than the hydraulic oil. The float member 70 is preferably formed in a rectangular plate shape having substantially the same shape as the cross-sectional shape of the hydraulic tank 60 so as to cover substantially the entire oil level of the hydraulic oil in the hydraulic tank 60. The shape of the float member 70 is not limited to the rectangular plate shape, and may be another shape that covers substantially the entire oil level of the hydraulic oil, depending on the cross-sectional shape of the hydraulic tank 60. By arranging the float member 70 in the hydraulic tank 60 so as to cover the entire oil level of the hydraulic oil in this way, fluctuations in the oil level during braking, acceleration, and the like can be effectively suppressed.

A through hole 71 into which the return oil passage 52 is inserted is provided at a portion of the float member 70 adjacent to the first side plate portion 62. The through hole 71 may be formed by a concave groove in which the edge portion adjacent to the first side plate portion 62 of the float member 70 is recessed, as long as the shape allows the return oil passage 52 to be inserted.

The collection mechanism 80 is a hinge mechanism that rotatably connects the mesh member 81 (an example of a partition member) immersed in the hydraulic oil below the float member 70 in the hydraulic tank 60 to the float member 70. It is equipped with 82.

The net-like member 81 is formed in a substantially plate shape by a metal mesh or the like having a plurality of small holes, and collects air bubbles in the hydraulic oil. Each small hole of the net-like member 81 is preferably formed to have a diameter smaller than the diameter of bubbles generated in the hydraulic oil. The hole diameter of each small hole of the net-like member 81 may be appropriately set according to the viscosity of the hydraulic oil actually used.

The net-like member 81 extends obliquely downward from the end of the float member 70 on the second side plate portion 63 side toward the bottom plate portion 64 in the hydraulic oil in the oil tank 60. Specifically, one end 81A of the net-like member 81 is rotatably connected and supported at the end of the float member 70 on the second side plate portion 63 side via a hinge mechanism 82. Further, the other end 81B of the net-like member 81 is a free end that contacts the bottom plate portion 64 facing the outlet end of the return oil passage 52.

The length L1 from one end 81A to the other end 81B of the mesh member 81 is a through hole from the end of the float member 70 on the second side plate portion 63 side in order to prevent the other end 81B from interfering with the return oil passage 52. It is formed shorter than the length L2 up to 71 (L1 <L2). Further, the length L1 of the mesh member 81 is the height of the oil level when the hydraulic oil is most returned to the oil tank 60 so as to reliably partition the hydraulic oil between the return oil passage 52 side and the suction oil passage 53 side. It is formed longer than the H (height from the bottom) (L1> H).

In the state shown in FIG. 3 in which the hydraulic oil is most returned to the oil tank 60, the hydraulic oil in the oil tank 60 is divided into a return oil passage 52 side and a suction oil passage 53 side by a mesh member 81. From this state, when the hydraulic oil in the oil tank 60 is pumped to the pump motor 41 (see FIGS. 1 and 2) through the suction oil passage 53, the oil level of the hydraulic oil drops as shown in FIG. Following this, the float member 70 also descends. While the float member 70 descends, the net-like member 81 rotates relative to the float member 70 so that the other end 81B draws an arc with the hinge mechanism 82 on the one end 81A side as a fulcrum, and the posture of the float member 70 descends. By changing the inclination angle with respect to the bottom plate portion 64 so as to be gradually reduced in conjunction with the above, the hydraulic oil is always partitioned between the return oil passage 52 side and the suction oil passage 53 side.

As a result, the bubbles generated in the hydraulic oil on the return oil passage 52 side of the mesh member 81 flow from the return oil passage 52 side toward the suction oil passage 53 side and pass through the mesh member 81. , The net-like member 81 ensures that the oil is collected. The air bubbles collected in the net-like member 81 increase the buoyancy while binding to each other, and reach the oil surface while floating diagonally upward along the net-like member 81, so that the air bubbles in the hydraulic oil are surely removed. It has become like.

According to the first embodiment described in detail above, the float member 70 is provided in the oil tank 60 to cover substantially the entire oil level of the hydraulic oil. This makes it possible to effectively suppress fluctuations in the oil level in the oil tank 60 caused by vibrations such as during braking and acceleration.

Further, one end 81A of the mesh member 81 capable of collecting air bubbles in the hydraulic oil is rotatably connected to the float member 70 by a hinge mechanism 82, and the posture of the mesh member 81 is interlocked with the descent of the float member 70. By changing the above, the hydraulic oil in the oil tank 60 is configured to be constantly partitioned between the return oil passage 52 side and the suction oil passage 53 side by the mesh member 81. As a result, when the hydraulic oil flows from the return oil passage 52 side toward the suction oil passage 53 side and passes through the mesh member 81, it is possible to reliably collect the bubbles in the hydraulic oil on the mesh member 81. Become. Further, by causing the air bubbles collected in the net-like member 81 to reach the oil surface while floating along the net-like member 81, the air bubbles can be reliably removed from the hydraulic oil. Further, by removing air bubbles from the hydraulic oil, it is possible to effectively suppress malfunction of the pump motor 41 due to air mixing.

[Second Embodiment]
FIG. 5 is a schematic vertical cross-sectional view showing the oil tank 60, the float member 70, and the collection mechanism 80 according to the second embodiment.

In the second embodiment, the second net-like member 83 and the second hinge mechanism 84 are further added to the collection mechanism 80 of the first embodiment.

Specifically, one end 81A of the first net-like member 81 is rotatably connected and supported at the end of the float member 70 on the second side plate portion 63 side via the first hinge mechanism 82. The second net-like member 83 is preferably formed of a metal mesh or the like having a coarser mesh (larger diameter of small holes) than the first net-like member 81. One end 83A of the second net-like member 83 is rotatably connected and supported at a predetermined portion between the end of the float member 70 on the second side plate portion 63 side and the through hole 71 via the second hinge mechanism 84. ..

In the state shown in FIG. 5 in which the hydraulic oil is most returned to the oil tank 60, the hydraulic oil in the oil tank 60 is divided into three by a first net-like member 81 and a second net-like member 83. From this state, when the hydraulic oil in the oil tank 60 is pumped to the pump motor 41 (see FIGS. 1 and 2) through the suction oil passage 53, the oil level of the hydraulic oil drops as shown in FIG. Following this, the float member 70 also descends. While the float member 70 descends, the first net-like member 81 and the second net-like member 83 change their postures while rotating relative to the float member 70 with the hinge mechanisms 82 and 84 as fulcrums to change the hydraulic oil. Is configured to be constantly divided into three parts.

As a result, the air bubbles generated in the hydraulic oil on the return oil passage 52 side of the second net-like member 83 flow from the return oil passage 52 side toward the suction oil passage 53 side to cause the second net-like member 83. When passing through, the air bubbles collected by the second net-like member 83 and further passing through the second net-like member 83 are collected by the first net-like member 81 when the hydraulic oil passes through the first net-like member 81. Will be collected. The bubbles collected in the reticulated members 81 and 83 increase the buoyancy while coupling with each other, and reach the oil surface while floating diagonally upward along the reticulated members 81 and 83 to reach the oil surface, thereby causing bubbles in the hydraulic oil. Is surely removed.

That is, according to the collection mechanism 80 of the second embodiment, the bubbles in the hydraulic oil are separated by the second net-like member 83 and the first net-like member 81 in two steps while exhibiting the same action and effect as those of the first embodiment. By collecting, it becomes possible to more reliably collect and remove air bubbles in the hydraulic oil.

[Other]
It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the gist of the present disclosure.

For example, as shown in FIG. 7, an air storage portion 75 that protrudes while curving upward is provided at the end of the float member 70 on the second side plate portion 63 side, and air is evacuated at the top of the air storage portion 75. A hole 76 may be provided. By providing the air storage unit 75 and the air vent hole 76 in this way, the air vent holes 76 collect the collected air while effectively collecting the air bubbles floating along the net-like member 81 in the air storage unit 75. By releasing from the oil, it becomes possible to more reliably separate and remove the air bubbles that have reached the oil surface from the hydraulic oil.

Further, in the second embodiment, the number of the mesh members 81 and 83 is not limited to two, and three or more may be provided depending on the capacity of the oil tank 60.

Further, the application of the present disclosure is not limited to the oil tank 60 for storing the hydraulic oil of the hydraulic hybrid vehicle 1, but is an oil pan for storing engine oil or mission oil, or another tank for storing a liquid other than oil. It can be widely applied to structures (for example, fuel tanks, etc.).

1 Hydraulic hybrid vehicle 10 Engine 12 Clutch device 13 Propeller shaft 20 Transmission 24 Differential gear device 25, 26 Drive shaft 27, 28 Drive wheel 40 Regeneration device 41 Pump motor 42 Accumulator (accumulator)
50 Hydraulic circuit 51 Supply oil passage 52 Return oil passage (return flow path)
53 Suction oil passage (feed flow path)
60 Oil tank (tank)
70 Float member 80 Collection mechanism 81 Net-like member (partition member)
82 Hinge mechanism

Claims (6)

A tank for storing liquid and
A feed flow path for feeding the liquid from the tank and
A return flow path for returning the liquid into the tank,
A float member that floats on the liquid in the tank,
One end is rotatably connected to the float member, and the other end is a free end that contacts the bottom of the tank, partitioning the liquid in the tank into the return flow path side and the feed flow path side. With a partition member,
The partition member is characterized in that a plurality of holes capable of collecting air bubbles contained in the liquid are formed while allowing the liquid to flow from the return flow path side to the feed flow path side. Liquid storage structure. The partition member changes its posture while rotating with one end as a fulcrum in conjunction with the drop of the float member accompanying the drop of the liquid level in the tank, thereby causing the liquid in the tank to move. The liquid storage structure according to claim 1, wherein the return flow path side and the feed flow path side are always partitioned. The liquid storage structure according to claim 1 or 2, wherein the float member is formed in the same shape as the cross-sectional shape of the tank and covers the entire liquid level of the liquid in the tank. The liquid storage structure according to any one of claims 1 to 3, wherein the partition member is formed of a mesh member having a plurality of small holes. As the partition member, a first partition member on the feed flow path side and a second partition member on the return flow path side are provided, and the hole of the second partition member has a smaller diameter than the hole of the first partition member. The liquid storage structure according to any one of claims 1 to 4, which is formed. The liquid storage structure according to any one of claims 1 to 5, wherein the liquid storage structure is a hydraulic oil storage structure for a hydraulic hybrid vehicle.
The hydraulic hybrid vehicle operates as a motor with an accumulator and hydraulic oil supplied from the accumulator to transmit power to the drive wheels, and operates as a pump with the power transmitted from the drive wheels to operate the accumulator. A pump motor for accumulating pressure is provided, and when the pump motor operates as a motor, hydraulic oil is returned to the tank via the return flow path and the pump motor operates as a pump. , A hydraulic oil storage structure for a hydraulic hybrid vehicle, characterized in that hydraulic oil is pumped from the tank through the feed flow path.

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