JP2008230332A - Reservoir tank structure of vehicle electrohydraulic power steering system - Google Patents

Abstract

[PROBLEMS] To improve workability when injecting hydraulic oil into a tank through an opening formed in an upper portion of a reservoir tank without impairing the leakage prevention performance of hydraulic oil and the prevention of air mixing into a hydraulic circuit. To do.
A reservoir tank 10 assembled to a vehicle body and containing a predetermined amount of hydraulic oil therein and provided with an air communication path Ap at an upper portion thereof is divided into two partition plates 13 that divide the tank interior vertically. 14 at a desired interval, the lower partition plate 14 has a communication hole 14a penetrating in the vertical direction at one end, and the upper partition plate 13 has a communication hole 13a penetrating in the vertical direction at the other end. It is formed in the part. In a state where the reservoir tank 10 is not inclined, at least the upper partition plate 13 is disposed above the oil level Lo of the hydraulic oil stored in the reservoir tank 10. A pair of suction ports 21 and 22 of the reversible electric hydraulic pump 20 are provided at the bottom of the reservoir tank 10.
[Selection] Figure 2

Description

  The present invention relates to a reservoir tank structure for an electro-hydraulic power steering device for a vehicle, and more particularly, a reservoir tank that is assembled to a vehicle body and accommodates a predetermined amount of hydraulic oil and has an air communication passage in an upper portion thereof, and a steering A reversible electric hydraulic pump that operates according to force and sucks and discharges hydraulic oil in the reservoir tank, a control valve that operates according to the operation of the electric hydraulic pump, and the control valve and the electric hydraulic pump A hydraulic actuator that operates in response to the supply and discharge of hydraulic oil controlled by the cooperative action of the two and outputs a steering assist force. The present invention can be applied to a reservoir tank that is employed in a vehicular electrohydraulic power steering apparatus.

A reservoir tank employed in the above-described vehicular electro-hydraulic power steering apparatus is described in Patent Document 1 below, for example. In the reservoir tank described in Patent Document 1, even when the vehicle body is tilted to one side or the other (for example, left side or right side), if the tilt angle is within an allowable tilt angle, the operation in the reservoir tank is performed. In order to prevent oil from leaking out of the reservoir tank through the atmosphere communication path provided at the top of the reservoir tank, and so that the pair of intake ports of the electric hydraulic pump provided at the bottom of the reservoir tank is not exposed to the air. The inner diameter of the opening formed in the upper part of the tank (the part through which hydraulic oil can be injected into the tank and the cap that can be vented is removably assembled) is reduced. In addition, a filter is provided in each of the pair of suction ports of the electric hydraulic pump provided at the bottom of the reservoir tank.
JP 2006-112361 A

  In the reservoir tank structure described in Patent Document 1 described above, since the inner diameter of the opening formed in the upper part of the reservoir tank is small, workability when injecting hydraulic oil into the tank through this is poor. In addition, since a pair of suction ports of the electric hydraulic pump provided at the bottom of the reservoir tank is provided with a filter, and the area of the filter is small, clogging is likely to occur. Various problems associated with defects) are likely to occur.

  The present invention has been made to cope with the above-described problems, and is provided with a reservoir tank that is assembled to a vehicle body and accommodates a predetermined amount of hydraulic oil therein and has an air communication passage at an upper portion thereof, and according to a steering force. A reversible electric hydraulic pump that operates and sucks and discharges the hydraulic oil in the reservoir tank, a control valve that operates in accordance with the operation of the electric hydraulic pump, and cooperation between the control valve and the electric hydraulic pump A hydraulic actuator that operates according to supply / discharge of hydraulic oil controlled by action and outputs a steering assist force is provided, and a pair of suction ports of the electric hydraulic pump are provided at the bottom of the reservoir tank. In the vehicular electro-hydraulic power steering apparatus, the reservoir tank includes two partition plates that divide the inside of the tank up and down at desired intervals, and the lower partition plate includes A communication hole penetrating in the downward direction is formed at one end, and a communication hole penetrating in the vertical direction is formed in the upper partition plate at the other end, so that the reservoir tank is not inclined and at least the upper The partition plate is characterized in that it is disposed above the oil level of the hydraulic oil stored in the reservoir tank.

  In the reservoir tank structure of the electrohydraulic power steering device for a vehicle according to the present invention, for example, when the vehicle body is tilted to one side within an allowable tilt angle (when tilted so that one end portion is downward), the reservoir tank is also one side. Although inclined, the upper partition plate prevents the hydraulic oil from flowing toward the upper portion of the reservoir tank, and the oil level in the reservoir tank below the lower partition plate is maintained at a high position. Further, for example, when the vehicle body is tilted to the other side within an allowable tilt angle (when the other end portion is tilted downward), the reservoir tank is also tilted to the other side, but the hydraulic oil is stored in the reservoir tank by the lower partition plate. The oil level in the reservoir tank below the lower partition plate is maintained at a high position.

  For this reason, in the present invention, even if the inner diameter of the opening formed in the upper part of the reservoir tank is large, the hydraulic oil in the reservoir tank leaks out of the reservoir tank through the atmospheric communication path provided in the upper part of the reservoir tank. In addition to being able to accurately prevent, it is possible to accurately prevent the suction port of the electric hydraulic pump provided at the bottom of the reservoir tank from being exposed to air, including an electric hydraulic pump, a control valve, etc. It is possible to accurately prevent air from entering the hydraulic circuit. Therefore, in the present invention, it is possible to improve the workability when injecting hydraulic oil into the tank through the opening formed in the upper part of the reservoir tank, and include an electric hydraulic pump, a control valve, and the like. It is possible to prevent problems caused by air mixing into the hydraulic circuit.

  In the present invention, the vertical position of the upper partition plate and the lower partition plate in the reservoir tank is appropriately set in relation to the oil level (the vertical position of the upper partition plate and the lower partition plate). Can be changed using a spacer, etc.) to change the above characteristics when the vehicle body is tilted to one side or the other (performance to prevent hydraulic oil leakage and performance to prevent air from entering the hydraulic circuit) Therefore, it can be optimally implemented for various vehicles having different allowable inclination angles of the vehicle body, and is highly versatile.

  Further, when the present invention is implemented, the electric reservoir is accommodated in the reservoir tank with the pair of suction ports opened upward at the bottom of the center of the tank. Between the partition plates, there is interposed a support member that is accommodated in the hydraulic oil stored in the reservoir tank and surrounds the two suction ports from the periphery. The support member is connected to the two suction ports. It is also possible to assemble a filter for preventing foreign matter from entering and to provide a conduction path for guiding the hydraulic oil toward the filter. In this case, it is possible to prevent foreign matter from being mixed into both suction ports with a single filter, and it is possible to arrange a filter with a large area, which can suppress clogging of the filter, It is possible to improve the detachability of the filter.

  When the present invention is implemented, a third partition plate for vertically dividing the tank interior is provided above the upper partition plate, and the third partition plate communicates vertically. It is also possible that a hole is formed at one end. In this case, for example, the hydraulic oil is directed upward of the tank (a space between the lower partition plate and the upper partition plate) through a communication hole formed in the lower partition plate with the reservoir tank inclined to the other side. Even if the hydraulic oil leaks and flows upward through the communication hole formed in the upper partition plate, the hydraulic oil flows further upward through the third partition plate. Accurately prevented.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of a vehicular electrohydraulic power steering apparatus. The vehicular electrohydraulic power steering apparatus is assembled with a reservoir tank 10 that is assembled to a vehicle body and contains a predetermined amount of hydraulic oil therein, and A reversible electric hydraulic pump 20 that sucks and discharges hydraulic oil in the reservoir tank 10, a fail-safe valve 30 and a back pressure control valve 40 that are interposed in a hydraulic circuit including the electric hydraulic pump 20, and A hydraulic cylinder 50 is provided as a hydraulic actuator that operates according to supply and discharge of hydraulic oil controlled by the cooperative action of the valves 30 and 40 and the electric hydraulic pump 20 and outputs a steering assist force.

  The electric hydraulic pump 20 is a trochoid pump that is driven to rotate forward and backward by an electric motor M, the operation of which is controlled by an electric control unit ECU, and as shown in FIG. The bottom of the reservoir tank 10 is housed in a state of opening upward at the bottom. Note that suction check valves 23 and 24 are interposed in the suction ports 21 and 22, respectively.

  In the electric hydraulic pump 20, when the electric motor M rotates forward in accordance with the leftward steering torque detected by the torque sensor St (see FIG. 1), the hydraulic oil discharged from the electric hydraulic pump 20 passes through the oil path P1. While being supplied to the oil chamber R1 of the hydraulic cylinder 50, the hydraulic oil in the oil chamber R2 of the hydraulic cylinder 50 is discharged to the electric hydraulic pump 20 or the reservoir tank 10 through the oil passage P2. Thereby, the hydraulic cylinder 50 outputs a steering assist force in the left direction.

  Further, in the electric hydraulic pump 20, when the electric motor M rotates in reverse according to the steering torque in the right direction detected by the torque sensor St, the hydraulic oil discharged from the electric hydraulic pump 20 passes through the oil passage P2 and the hydraulic cylinder 50. The hydraulic oil in the oil chamber R1 of the hydraulic cylinder 50 is discharged to the electric hydraulic pump 20 or the reservoir tank 10 through the oil passage P1. Thereby, the hydraulic cylinder 50 outputs a steering assist force in the right direction.

  The fail-safe valve 30 disables manual steering when the apparatus is normal, and enables manual steering when the apparatus is abnormal. As shown in FIG. 1, both the oil paths P1, P2 and the reservoir tank 10 A normally-open electromagnetic switching valve 31 that is closed by energization and opened by non-energization to allow a free flow of hydraulic oil to the reservoir tank 10, and a pair of left and right The check valves 32 and 33 are used. Note that the operation of the electromagnetic switching valve 31 is configured to be controlled by the electric control unit ECU.

  The back pressure control valve 40 controls communication / blocking between the reservoir tank 10 and the oil chambers R1 and R2 of the hydraulic cylinder 50. As shown in FIG. 1, both the oil paths P1 and P2 and the reservoir tank 10 is connected to a connecting oil passage P4, and includes a pair of left and right pressure control valves 41 and 42 and one check valve 43. The pressure control valve 41 on the left side of the figure is set to open and allow free flow to the tank side when the oil pressure in the oil path P1 on the right side of the figure reaches a predetermined pressure. The right pressure control valve 42 in the figure is set to open and allow free flow to the tank side when the oil pressure in the left oil passage P2 reaches a predetermined pressure.

  By the way, in this embodiment, as shown in FIG. 2, the reservoir tank 10 includes a tank main body 11 and a cap 12, and two partition plates 13 and 14 that partition the inside of the tank vertically, A spacer 15 and a support 16 are provided between the suction portion of the hydraulic pump 20 and the lower partition plate 14.

  The tank body 11 has an opening 11a at the upper end, and is liquid-tightly assembled at the lower end to the housing 29 of the electric hydraulic pump 20, and has a required amount of hydraulic oil (in FIG. 2). The oil level Lo) indicated by a two-dot chain line is accommodated. The tank body 11 is formed of a resin material that allows the oil level inside to be visually recognized from the outside.

  The cap 12 is detachably attached to a threaded portion 11b formed on the outer periphery of the upper end portion of the tank body 11, and the air that always allows air flow between the tank interior and the tank exterior between the tank body 11 and the cap 12. A communication path Ap is formed. As a result, the atmospheric pressure is always applied to the hydraulic oil in the reservoir tank 10.

  The upper partition plate 13 is assembled in a liquid-tight manner in the tank body 11 via a seal ring O1 so as to overlap the lower partition plate 14, and at the left end of the figure in the vertical direction A communication hole 13a penetrating therethrough is formed. The lower partition plate 14 is assembled in a liquid-tight manner between the upper partition plate 13 and the spacer 15 in the tank body 11 via a seal ring O2, and in the vertical direction at the right end of the figure. A communication hole 14a is formed therethrough. Both partition plates 13 and 14 are made of hydraulic oil stored in the reservoir tank 10 in a state where the reservoir tank 10 is not inclined (the state shown in FIG. 2 is not inclined with respect to a vertical line perpendicular to the horizontal line). It is arranged above the oil level Lo.

  The spacer 15 is formed in a cylindrical shape, and is assembled in the tank body 11 between the lower partition plate 14 and the support body 16, and is a resin that allows the internal oil level to be visually seen from the outside. It is made of material. The support 16 is formed in a cylindrical shape, and is interposed between the spacer 15 and the suction part of the electric hydraulic pump 20 in the tank body 11, and a seal is provided between the suction part of the electric hydraulic pump 20. A ring O3 is interposed.

  The support body 16 is housed in hydraulic oil housed in the tank, and surrounds both the suction ports 21 and 22 of the electric hydraulic pump 20 from the periphery, and inside the suction port 21 of the electric hydraulic pump 20. , 22 is attached with a filter 17 for preventing foreign matter from entering. In addition, a notch 16 a is formed at the upper end portion of the support body 16, and a conduction path that guides hydraulic oil toward the filter 17 is formed by the notch 16 a. Note that when the apparatus is operating normally, hydraulic oil discharged through the back pressure control valve 40 is guided toward the filter 17 through the notch 16a.

  In the reservoir tank structure of this embodiment configured as described above, for example, when the vehicle body is tilted to the right in FIG. 2 within the allowable tilt angle θR (when the right end is tilted downward), As shown in FIG. 3, although the reservoir tank 10 is also inclined to the right at an inclination angle θ with respect to the vertical line, the upper partition plate 13 prevents the hydraulic oil from flowing toward the upper part of the reservoir tank 10. In addition, the oil level in the reservoir tank 10 below the lower partition plate 14 is maintained at a high position.

  Further, for example, when the vehicle body is tilted to the left in FIG. 2 within an allowable tilt angle θL (when tilted so that the left end portion is downward), the reservoir tank 10 is also in a vertical line as shown in FIG. On the other hand, although it is inclined to the left at an inclination angle θ, the lower partition plate 14 prevents the hydraulic oil from flowing toward the upper portion of the reservoir tank 10, and the reservoir tank 10 below the lower partition plate 14. The oil level inside is maintained at a high position.

  For this reason, even if the inner diameter of the opening 11a formed at the upper end of the tank body 11 is large as shown in FIG. Leaking out of the reservoir tank 10 through the reservoir tank 10 and accurately preventing both the inlets 21 and 22 of the electric hydraulic pump 20 provided at the bottom of the reservoir tank 10 from being exposed to air. Thus, it is possible to accurately prevent air from entering the hydraulic circuit including the electric hydraulic pump 20, the fail safe valve 30, the back pressure control valve 40, and the like. Therefore, it is possible to improve the workability when injecting hydraulic oil into the tank through the opening 11a formed in the upper part of the reservoir tank 10, and the electric hydraulic pump 20, both valves 30, 40, etc. It is possible to prevent problems caused by air mixing into the hydraulic circuit.

  Further, in this embodiment, the vertical position of the upper partition plate 13 and the lower partition plate 14 in the reservoir tank 10 is appropriately set in relation to the oil level (the upper partition plate 13 and the lower partition plate 14). By adjusting the vertical position of the plate 14 using a spacer or the like, the characteristics described above when the vehicle body is tilted to the right or left (prevention of leakage of hydraulic oil, prevention of air from entering the hydraulic circuit) Since the performance can be changed, it can be optimally applied to various vehicles having different allowable inclination angles of the vehicle body, and is highly versatile.

  Further, in the reservoir tank 10 of this embodiment, the electric hydraulic pump 20 is accommodated with the pair of suction ports 21 and 22 opened upward at the center bottom of the tank. And a lower partition plate 14 is provided with a support 16 which is accommodated in the hydraulic oil stored in the reservoir tank 10 and surrounds both the suction ports 21 and 22 from the periphery. A filter 17 for preventing foreign matter from entering both the suction ports 21 and 22 is assembled to the filter, and a conduction path (notch 16a) for guiding hydraulic oil toward the filter 17 is provided. For this reason, it is possible to prevent foreign matter from entering both the suction ports 21 and 22 with one filter 17, and it is possible to arrange the filter 17 having a larger area than the opening area of each suction port 21 and 22. The clogging of the filter 17 can be suppressed, and the detachability of the filter 17 can be improved.

  In the above embodiment, the partition plates 13 and 14 in the reservoir tank 10 are above the oil level Lo of the hydraulic oil stored in the reservoir tank 10 in a state where the reservoir tank 10 is not inclined (the state shown in FIG. 2). Although the present invention has been implemented with the arrangement being arranged, at the time of implementing the present invention, at least the upper partition plate 13 is made of the hydraulic oil stored in the reservoir tank 10 in a state where the reservoir tank 10 is not inclined. What is necessary is just to comprise so that it may be arrange | positioned above the oil level Lo, and the lower partition plate 14 is arrange | positioned below the oil level Lo of the hydraulic oil accommodated in the reservoir tank 10 in the state where the reservoir tank 10 is not inclined. It can also be configured and implemented.

  Further, in the above embodiment, the two partition plates 13 and 14 are provided at a desired interval in the reservoir tank 10, but as shown in FIG. It is also possible to provide a third partition plate 19 that divides the upper and lower sides. The third partition plate 19 is assembled in a liquid-tight manner in the tank body 11 via a seal ring O4 so as to overlap the upper partition plate 13, and the right end in the figure is A communication hole 19a penetrating in the direction is formed.

  In the embodiment shown in FIG. 5, for example, when the reservoir tank 10 is tilted to the left (see the state of FIG. 4), the hydraulic oil passes through the communication hole 14 a formed in the lower partition plate 14. And the hydraulic fluid may flow upward through the communication hole 13a formed in the upper partition plate 13. However, the hydraulic oil is accurately prevented from flowing further upward by the third partition plate 19.

1 is a diagram schematically showing an overall configuration of a vehicular electrohydraulic power steering apparatus including a reservoir tank embodying the present invention. FIG. 2 is an enlarged longitudinal sectional view of main parts of a reservoir tank, an electric hydraulic pump, an electric motor, etc. shown in FIG. 1. FIG. 3 is an operation explanatory diagram in a state in which the reservoir tank, the electric hydraulic pump, the electric motor, and the like illustrated in FIG. FIG. 3 is an operation explanatory diagram illustrating a state in which the reservoir tank, the electric hydraulic pump, the electric motor, and the like illustrated in FIG. It is a principal part longitudinal cross-sectional enlarged sectional view equivalent to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Reservoir tank, 11 ... Tank main body, 11a ... Opening part, 12 ... Cap, 13 ... Upper partition plate, 13a ... Communication hole provided in upper partition plate, 14 ... Lower partition plate, 14a ... Lower partition Communication holes provided in the plate, 15 ... spacer, 16 ... support, 16a ... notch (conduction path), 17 ... filter, 20 ... electric hydraulic pump, 21, 22 ... suction port, 30 ... fail-safe valve, 40 ... back Pressure control valve, 50 ... hydraulic cylinder, Ap ... atmospheric communication path, Lo ... hydraulic oil level, M ... electric motor, ECU ... electric control device

Claims (3)

A reservoir tank that is assembled to the vehicle body and contains a predetermined amount of hydraulic oil inside and has an air communication path at the top, and a reversible that operates according to the steering force and sucks and discharges the hydraulic oil in the reservoir tank An electric hydraulic pump of the type, a control valve that operates according to the operation of the electric hydraulic pump, and an operation that responds to supply / discharge of hydraulic oil controlled by the cooperative action of the control valve and the electric hydraulic pump. In the vehicular electric hydraulic power steering apparatus comprising a hydraulic actuator that outputs a steering assist force, wherein a pair of suction ports of the electric hydraulic pump is provided at the bottom of the reservoir tank,
The reservoir tank is provided with two partition plates that divide the inside of the tank up and down at a desired interval, and a communication hole that penetrates in the vertical direction is formed in one end of the lower partition plate, and the upper partition The plate is formed with a communication hole penetrating in the vertical direction at the other end portion, and at least the upper partition plate in a state where the reservoir tank is not inclined from the oil level of the hydraulic oil stored in the reservoir tank. A reservoir tank structure for an electrohydraulic power steering apparatus for a vehicle, wherein the reservoir tank structure is disposed above.   2. The reservoir tank structure for an electro-hydraulic power steering apparatus for a vehicle according to claim 1, wherein the electro-hydraulic pump is stored in the reservoir tank in a state in which a pair of suction ports are opened upward at the bottom center of the tank. In addition, a support body is interposed between the electric hydraulic pump and the lower partition plate so as to be contained in the hydraulic oil contained in the reservoir tank and surround both the suction ports from the surroundings. The vehicle is equipped with a filter for preventing foreign matter from entering the two suction ports, and is provided with a conduction path for guiding hydraulic oil toward the filter. Power steering device reservoir tank structure.   The reservoir tank structure of the electrohydraulic power steering apparatus for a vehicle according to claim 1 or 2, wherein a third partition plate that divides the inside of the tank vertically is provided above the upper partition plate. A reservoir tank structure for a vehicular electrohydraulic power steering apparatus, wherein a communication hole penetrating in the vertical direction is formed at one end of the third partition plate.

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