JP6256146B2 - Hydraulic accumulator and vehicle travel control device including the same - Google Patents

Description

  The present invention relates to a hydraulic accumulator that can be used as a travel drive source of a vehicle, and a vehicle travel control device including the same.

  In recent years, in order to improve the fuel consumption performance of vehicles, regenerative energy obtained during deceleration traveling is not only stored as electric power in a battery but also stored as hydraulic pressure in a hydraulic accumulator, and vehicles used during acceleration traveling have been put into practical use.

  For example, the invention disclosed in Patent Document 1 discloses a hydraulic accumulator in which a piston that separates a space in which hydraulic oil is stored from a space filled with nitrogen is provided so as to be movable in the longitudinal direction within the housing. The energy stored in the hydraulic accumulator is converted into work to be performed on the outside of the hydraulic accumulator through the piston.

Special table 2008-512616 gazette

  However, the conventional hydraulic accumulator described in Patent Document 1 has a small amount of work that can be performed to the outside, and the electric power stored in the battery is used as a driving force at an early stage of starting or accelerating. It was necessary to use as. This is not preferable in that the life of the battery is deteriorated as the number of times of charging / discharging increases.

  In order to solve the above problems, it is conceivable to increase the work amount by increasing the size of the hydraulic accumulator. However, in this case, the mounting property on the vehicle is deteriorated.

  Therefore, an object of the present invention is to increase the amount of work that the hydraulic accumulator can do to the outside without increasing the size of the hydraulic accumulator.

In order to achieve the above object, the invention described in claim 1 of the present application is
A housing;
A partition member provided slidably in the housing,
An oil storage chamber for storing hydraulic oil supplied from a hydraulic pump motor by the partition member is a hydraulic accumulator separated from a gas chamber filled with gas,
An operation of biasing the partition member toward the oil storage chamber when the hydraulic oil is discharged from the oil storage chamber, and the partition member when the hydraulic oil is supplied from the hydraulic pump motor to the oil storage chamber An electric partition member urging means for urging the gas chamber toward the gas chamber is provided ,
The partition member urging means has a permanent magnet attached to the partition member, and two electromagnets provided on both the gas chamber side and the oil storage chamber side facing the permanent magnet,
As the partition member moves, when the magnetic force applied to the partition member from one of the two electromagnets exceeds the magnetic force applied to the partition member from the other, the energization state of the two electromagnets is switched. It is characterized by.

The invention according to claim 2 is the invention according to claim 1 ,
And when discharging the hydraulic oil from the each of the electromagnets provided in the gas chamber and the oil storage chamber, said oil storage chamber, reversed between when the working oil is supplied from the hydraulic pump motor to the oil storage chamber It is characterized in that energization is performed so as to generate a magnetic field in the direction.

The invention according to claim 3 is the invention according to claim 1 or 2 ,
The partition member urging means further includes a heating means for heating the gas in the gas chamber.

The invention according to claim 4 is the invention according to claim 3 ,
The housing has a heat insulating structure.

The invention according to claim 5 relates to a vehicle travel control device,
A motor generator that stores electric power in at least one of a battery and a capacitor by rotation of a drive wheel when hydraulic oil is supplied from the hydraulic pump motor to the oil storage chamber;
A hydraulic accumulator according to any one of claims 1 to 4 ,
The partition member urging means is actuated by electric power supplied from the capacitor.

  With the above configuration, according to the invention described in each claim of the present application, the following effects can be obtained.

According to the first aspect of the present invention, when the operation of urging the partition member toward the oil storage chamber is performed, the pressure rises when the hydraulic oil is discharged from the oil storage chamber. In addition, when the operation of urging the partition member toward the gas chamber is performed, the pressure of the gas enclosed in the gas chamber increases before the start of the discharge of the hydraulic oil, and the pressure is also reduced when the hydraulic oil is discharged. To rise. In this way, the amount of work that the hydraulic accumulator can do to the outside can be increased without increasing the size of the hydraulic accumulator.
Further, a repulsive force or an attractive force acting between the permanent magnet and the electromagnet applies a biasing force to the partition member, thereby specifically achieving the above effect.
In addition, it is possible to increase the amount of work that the hydraulic accumulator can do to the outside while limiting energy consumption due to power supply to the partition member urging means.

According to the invention described in claim 2 , when the hydraulic oil is discharged from the oil storage chamber, the partition member is biased toward the oil storage chamber, and when the hydraulic oil is supplied from the hydraulic pump motor, the partition wall is energized. The member is biased toward the gas chamber, and therefore the effects of claims 1 and 2 can be enhanced.

According to the third aspect of the present invention, the temperature and pressure of the gas sealed in the gas chamber increases due to the heat supplied from the heating means, that is, the energy stored in the hydraulic accumulator increases. Then, by increasing the energy before starting the discharge of the hydraulic oil, the pressure can be increased when the hydraulic oil is discharged. Thereby, the effect of claim 1 is specifically achieved.

Moreover, according to the invention of Claim 4 , it is suppressed that the heat supplied by the heating means escapes to the outside, and the effect of Claim 3 can be enhanced.

According to the fifth aspect of the present invention, the electric power generated by the motor generator at the time of regeneration is recovered by the capacitor, and the partition member urging means is operated by the electric power supplied from the capacitor, whereby the number of times of charging / discharging of the battery is reduced. It can be reduced and its life can be improved.

It is a block diagram showing a schematic structure of a vehicle provided with an accumulator concerning one embodiment of the present invention. FIG. 2 is a control block diagram of the vehicle shown in FIG. 1. It is sectional drawing which shows the accumulator which concerns on 1st Embodiment of this invention in the state to which hydraulic fluid was supplied. It is sectional drawing which shows the accumulator which concerns on 1st Embodiment of this invention in the state from which hydraulic fluid was discharged | emitted. It is a flowchart which shows control of the vehicle by one Embodiment of this invention. FIG. 2 is an efficiency diagram (a) of a motor generator and an efficiency diagram (b) of a hydraulic pump motor according to the traveling state of the vehicle shown in FIG. 1. It is sectional drawing which shows the accumulator which concerns on the modification of 1st Embodiment of this invention in the state to which hydraulic fluid was supplied. It is sectional drawing which shows the accumulator which concerns on 2nd Embodiment of this invention in the state to which hydraulic fluid was supplied.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a vehicle including an accumulator according to an embodiment of the present invention.
The vehicle 1 is an electric vehicle, and includes a motor generator (hereinafter referred to as M / G) 10 and a hydraulic pump motor (hereinafter referred to as hydraulic P / M) 40 as a travel drive source. The rotating shaft of the M / G 10 and the rotating shaft of the hydraulic pressure P / M 40 are integrated (indicated by reference numeral 73), and are always connected to the axle 71 and further to the drive wheels 74 and 75 via the differential device 72.

  M / G 10 is connected to battery 30 and capacitor 80 via inverter 20, and its operating state is controlled by inverter 20. The M / G 10 can operate as a motor by the electric power supplied from the battery 30 and can also operate as a generator by the rotation of the drive wheels 74 and 75. When the M / G 10 operates as a generator, electric power is stored in at least one of the battery 30 and the capacitor 80 in accordance with the control of the inverter 20.

  The capacitor 80 is connected to a coil 55 (described later) in the accumulator 50 via a DC-DC converter 90 as a voltage converter.

  The hydraulic pressure P / M 40 is connected to the accumulator 50 and the reservoir 60 through a pipe 41 constituting an oil passage. The accumulator 50 can store hydraulic oil in a pressurized state. The hydraulic P / M 40 can operate as a hydraulic pump that sucks hydraulic oil from the reservoir 60 and stores the hydraulic pressure in the accumulator 50, and can also operate as a hydraulic motor by the hydraulic pressure supplied from the accumulator 50. Whether the hydraulic P / M 40 operates as a hydraulic pump or a hydraulic motor is switched by a controller (not shown) attached to the hydraulic P / M 40.

  A bypass circuit 42 communicates with the pipe 41 between a high pressure oil passage (on the accumulator 50 side) and a low pressure oil passage (on the reservoir 60 side) of the hydraulic pressure P / M 40. Further, the piping 41 is provided with supply / discharge oil valves 43 and 44 for controlling the operation oil to enter and exit from the accumulator 50 and the reservoir 60, respectively. The bypass circuit 42 is provided with a bypass valve 45. When the supply / discharge oil valves 43 and 44 are opened and the bypass valve 45 is closed, the hydraulic oil is exchanged between the accumulator 50 and the reservoir 60 via the hydraulic pressure P / M 40. On the other hand, when the supply / discharge oil valves 43 and 44 are closed and the bypass valve 45 is opened, the hydraulic oil flows only in the closed circuit constituted by the oil path around the hydraulic pressure P / M 40 and the bypass circuit 42. Even if the rotating shaft of the hydraulic pressure P / M 40 rotates in this state, the drive wheels 74 and 75 are not driven by the hydraulic pressure stored in the accumulator 50, and no pressure is accumulated in the accumulator 50, that is, M / G 10 A state in which only is operating is realized.

  Even if the supply / discharge oil valves 43 and 44 are open, as long as the bypass valve 45 is open, the hydraulic oil hardly flows between the accumulator 50 and the reservoir 60 on the high load side. Is open, the state in which the hydraulic pressure P / M 40 does not operate and the M / G 10 operates is realized.

FIG. 2 is a control block diagram of the vehicle 1.
The vehicle 1 includes a VCM (vehicle control module) 100. The VCM 100 includes a vehicle speed sensor 101 that detects the speed of the vehicle 1, an accelerator opening sensor 102 that detects the amount of depression of the accelerator pedal, a pressure accumulation hydraulic pressure sensor 103 that detects a remaining oil pressure (accumulated pressure) stored in the accumulator 50, and A signal from the acceleration switch 104 or the like is input. The acceleration switch 104 is provided in a range where the driver can operate during driving, and the driver indicates the intention to perform the acceleration operation after a certain time by pressing the acceleration switch 104.

  The VCM 100 transmits control signals to the inverter 20, the supply / discharge oil valves 43 and 44, the bypass valve 45 and the coil 55, the output of the inverter 20, the opening of the supply / discharge oil valves 43 and 44 and the bypass valve 45, and the coil The energization state to 55 is controlled.

FIG. 3 is a cross-sectional view showing the configuration of the accumulator according to the first embodiment of the present invention.
The accumulator 50 includes a substantially cylindrical (cylindrical) housing 51 and a piston 54 that separates the oil storage chamber 52 and the gas chamber 53 in the housing 51. The oil storage chamber 52 stores hydraulic oil supplied from the hydraulic pressure P / M 40 through the pipe 41 inserted at the end. A gas such as nitrogen is sealed in the gas chamber 53. The gas sealed in the gas chamber 53 may be another gas as long as it is an inert gas. A head cover 58 is attached to the end of the gas chamber 53 so that the gas chamber 53 is kept airtight.

  The piston 54 is provided in the housing 51 so as to be slidable in the longitudinal direction. The piston 54 is provided with a grooved portion, and a ring-shaped seal member 54a is attached to the grooved portion. When the seal member 54 a comes into contact with the inner surface of the housing 51, the oil storage chamber 52 and the gas chamber 53 are reliably separated.

  A permanent magnet 57 is attached to the piston 54. The permanent magnet 57 is a columnar or cylindrical magnet with one pole magnetized on one side. The shape of the permanent magnet 57 can be arbitrarily designed depending on the shape of the piston 54 and the like.

  An electromagnet having a coil 55 and a core is provided at the end of the gas chamber 53. The electromagnet is provided to face the magnetic pole surface of the permanent magnet 57. The coil 55 is connected to the capacitor 80 via the DC-DC converter 90 by the wiring 56. The coil 55 is energized so as to create a magnetic field that repels the permanent magnet 57.

  In the first embodiment, the “electric partition wall member urging means” is realized by the permanent magnet 57 and the coil 55. This partition member biasing means has a function of applying a biasing force to a piston which is an example of a partition member.

  Returning to FIG. 1, the operation performed during driving and regeneration of the drive wheels 74 and 75 will be described. This operation is achieved by controlling the VCM 100. Description of the operation of the supply / discharge oil valves 43 and 44 is omitted.

  First, when the drive wheels 74 and 75 are driven and regenerated by electric power, the bypass valve 45 is closed and the bypass circuit 42 is closed. At this time, no hydraulic oil is exchanged between the accumulator 50 and the reservoir 60.

  When the driving wheels 74 and 75 are driven or regenerated by hydraulic pressure, the output from the inverter 20 to the M / G 10 or the battery 30 (or the capacitor 80) is restricted, while the bypass circuit 42 is opened. At this time, when driving, the hydraulic oil is discharged from the oil storage chamber 52 of the accumulator 50. At the same time, the coil 55 is energized to urge the piston 54 toward the oil storage chamber 52. FIG. 4 shows the accumulator 50 with the hydraulic oil discharged. This increases the pressure when the hydraulic oil is discharged. Energization of the coil 55 is stopped in accordance with the stoppage of hydraulic oil discharge. On the other hand, during regenerative operation, hydraulic oil is supplied from the hydraulic pressure P / M 40 to the oil storage chamber 52.

  Further, when the drive wheels 74 and 75 are driven or regenerated by both electric power and hydraulic pressure, the opening degree of the bypass valve 45 increases or decreases according to the output of the inverter 20.

  Next, the control of the VCM 100 according to the traveling state of the vehicle 1 will be specifically described.

FIG. 5 is a flowchart showing the control of the vehicle 1 according to the embodiment of the present invention.
First, signals from the sensors 101 to 104 are input to the VCM 100 (S1). Next, based on the signal from the vehicle speed sensor 101, it is determined whether the vehicle 1 is currently accelerating (S2). During acceleration traveling (Yes in S2), it is determined whether or not the accumulated oil pressure of the accumulator 50 is higher than a predetermined value P1 based on the signal from the accumulated oil pressure sensor 103 (S3). The predetermined value P1 is a sufficiently low value, for example, a value close to zero.

  When the accumulated hydraulic pressure is higher than the predetermined value P1 (Yes in S3), the bypass valve 45 is closed, the inverter 20 is stopped, and the vehicle 1 travels using the hydraulic pressure supplied from the accumulator 50 as a driving force (hereinafter, hydraulically driven traveling). (S4). At this time, the coil 55 is energized at the same time, and the piston 54 is biased toward the oil storage chamber 52 side. When the pressure accumulation hydraulic pressure decreases and becomes equal to or less than the predetermined value P1 (No in S3), the bypass valve 45 is opened, the inverter 20 is activated, and the vehicle 1 travels using electric power supplied from the battery 30 (hereinafter referred to as driving force) (Referred to as electric power driving) (S5).

  In the flowchart, only opening / closing of the bypass valve 45 is described, and opening / closing of the supply / discharge oil valves 43, 44 is not described. However, when the bypass valve 45 is opened, the supply / discharge oil valves 43, 44 are closed, and conversely. It is assumed that when the bypass valve 45 is closed, the supply / discharge oil valves 43 and 44 are controlled to open.

  If the vehicle 1 is not accelerating (S2 negative), it is determined whether the vehicle is decelerating (S6). If the vehicle is decelerating (Yes at S6), it is determined whether or not the accumulated hydraulic pressure of the accumulator 50 is lower than a predetermined value P2 (S7). The predetermined value P2 is a value higher than the predetermined value P1, and can be, for example, a hydraulic pressure value when the accumulator 50 is full.

  When the pressure accumulation hydraulic pressure is lower than the predetermined value P2 (Yes in S6), the bypass valve 45 is closed and the inverter 20 is stopped. Thereby, the energy of deceleration regeneration is collect | recovered by the pressure accumulation (henceforth hydraulic regeneration) to the accumulator 50 (S8). When the accumulated hydraulic pressure is equal to or greater than the predetermined value P2 (No in S6), the bypass valve 45 is opened and the inverter 20 is operated. Thereby, the energy of deceleration regeneration is collect | recovered by charge (henceforth electric power regeneration) to the battery 30 (S9).

  If the vehicle 1 is neither in acceleration traveling nor in deceleration traveling (No in S6), that is, in steady traveling, it is predicted whether or not the vehicle 1 will start acceleration traveling within a predetermined time (S10). In the present specification, “steady travel” includes a state where the vehicle travels from a certain speed to a slightly higher speed or a lower speed. When the acceleration switch 104 is pushed by the driver, it is predicted that acceleration traveling will be performed (Yes in S10), and then it is determined whether or not the accumulated hydraulic pressure of the accumulator 50 is lower than a predetermined value P2 (S11).

  In step S10, the presence or absence of accelerated traveling may be predicted using a means other than the acceleration switch 104, for example, a car navigation system that acquires vehicle route information. Specifically, it is possible to use information such as road surface gradients, curve curvatures, and whether or not the vehicle is approaching an expressway entrance / exit. Further, a past driving history may be stored in a storage unit (memory) provided in the car navigation system or the like, and this driving history may be used. Moreover, the time change of accelerator opening / closing may be calculated from the accelerator opening sensor 102, and this time change may be utilized.

  When the accumulator hydraulic pressure of the accumulator 50 is lower than the predetermined value P2 (Yes in S11), the bypass valve 45 is closed in preparation for acceleration travel, and hydraulic pressure regeneration is performed simultaneously with power drive travel. The hydraulic regeneration is performed until the accumulator 50 is full (S12). At this time, control for temporarily increasing the output of the M / G 10 is performed in order to compensate for a decrease in driving force due to hydraulic regeneration (S13). When the accumulated oil pressure of the accumulator 50 is equal to or greater than the predetermined value P2 (No in S11), no special control is performed until the acceleration travel is started.

  When acceleration is not predicted during steady traveling (No in S10), traveling based on an efficiency diagram (efficiency map) is performed (S14). Specifically, the efficiency diagram of M / G 10 shown in FIG. 6A and the efficiency diagram of hydraulic pressure P / M 40 shown in FIG. 6B are referred to, and the current running state (speed, output) of the vehicle 1 is referred to. ) On the efficiency diagram (revolution speed, torque) is specified. The efficiency diagram shows the energy transmission efficiency of M / G 10 and hydraulic pressure P / M 40 that change according to the rotation speed and torque. Hereinafter, it is assumed that the speed roughly corresponds to the rotational speed and the output roughly corresponds to the torque in the relationship between the traveling state of the vehicle 1 and the efficiency diagram. Then, it is determined which efficiency is higher between M / G10 and hydraulic pressure P / M40. When M / G10 is higher, power-driven traveling is performed, and when hydraulic pressure P / M40 is higher, hydraulic-driven traveling is performed. Done.

  Note that the efficiency diagram shown in FIG. 6 changes according to the types of M / G 10 and hydraulic pressure P / M 40 to be used, and is therefore only an example and does not limit the present invention.

  Further, although not shown in the flowchart of FIG. 5, when the accumulated hydraulic pressure becomes zero during the hydraulic drive traveling, the operation is automatically switched to the electric power drive traveling.

  Hereinafter, modified examples of the first embodiment will be described.

  In the first embodiment, an example has been described in which a magnetic field in which the coil 55 repels the permanent magnet 57 is generated by the coil 55 and the coil 55 is energized when the drive wheels 74 and 75 are driven. On the other hand, as a first modification, a magnetic field such that the coil 55 attracts the permanent magnet 57 may be created by the coil 55. In this case, the piston 54 is urged toward the gas chamber 53 when energized. Energization of the coil 55 is started during the supply of the hydraulic oil, and is stopped when the discharge of the hydraulic oil is started. As a result, the state in which the pressure of the gas sealed in the gas chamber 53 rises, that is, the energy stored in the accumulator 50 (the energy capacity of the accumulator 50) increases before the start of hydraulic oil discharge is realized. As a result, the pressure rises when the hydraulic oil is discharged.

  This first modification can be implemented in step S8 of the flowchart of FIG.

  Furthermore, as a second modification, the first embodiment and the first modification can be combined. That is, a magnetic field is created so that the coil 55 repels the permanent magnet 57 when the drive wheels 74 and 75 are driven, and a magnetic field is created so that the coil 55 attracts the permanent magnet 57 during regeneration. Good.

  This can be implemented, for example, using an electrode inversion circuit that inverts the connection between the wiring 56 and the positive and negative electrodes of the capacitor 80 between driving and regeneration. The electrode inversion circuit is configured by relays provided on the positive electrode side and the negative electrode side of the capacitor 80, for example. As a result, the pressure of the hydraulic oil discharged during driving further increases.

  As a third modification, as shown in FIG. 7, in addition to the end of the gas chamber 53, an electromagnet facing the magnetic pole surface of the permanent magnet 57 may be provided at the end of the oil storage chamber 52. A coil 155 is wound around the core of the electromagnet. The coil 155 is connected to the capacitor 80 via the DC-DC converter 90 by the wiring 156. When the electromagnet is provided only at the end of the gas chamber 53, for example, when driving the drive wheels 74 and 75, if the distance between the permanent magnet 57 and the coil 55 increases as the hydraulic oil is discharged, the coil 55 Unless the value of the flowing current is increased, the repulsive force acting between them continues to decrease. At this time, it is possible to suppress a reduction in repulsive force by energizing the coil 155 so as to create a magnetic field attracting the permanent magnet 57.

  At this time, when the magnetic force (biasing force) applied to the piston 54 from one of the two electromagnets exceeds the magnetic force applied to the piston 54 from the other electromagnet as the piston 54 moves, the two coils The energization state (ON and OFF) for 55 and 155 may be switched. Thereby, the effect of the third modified example can be obtained while restricting the energy consumption due to the power supply to the coils 55 and 155.

  Moreover, in 1st Embodiment, the structure of the electromagnet by which the coil 55 was wound around the core arrange | positioned in the gas chamber 53 was demonstrated. Since the coil 55 only needs to create a magnetic field that repels the magnetic field created by the permanent magnet 57, the coil 55 may be provided outside the housing 51 as a fourth modification.

  As described above, when hydraulic oil is discharged from the oil storage chamber 52, the pressure can be increased. This increases the amount of work that the accumulator 50 can do to the outside (drive wheels 74, 75).

(Second Embodiment)
In the first embodiment, the work that the accumulator 50 can do with respect to the drive wheels 74 and 75 is increased using magnetic force. On the other hand, the second embodiment is characterized in that the work amount is increased using heat.

FIG. 8 is a cross-sectional view showing an accumulator according to the second embodiment of the present invention in a state where hydraulic oil is supplied.
The accumulator 50 includes a PTC (Positive Temperature Coefficient) heater 255 instead of the combination of the permanent magnet 57 and the electromagnet of the first embodiment. The PTC heater 255 is a thermistor whose electrical resistance value increases as the temperature rises. The PTC heater 255 is an example of a heating unit, and an electric heater, an induction heating (IH) heater, or the like may be used. The PTC heater 255 heats the temperature of the gas in the gas chamber 53 to, for example, about 100 ° C. at the maximum.

  Although not shown in the cross-sectional view of FIG. 8, the housing 51 has a double wall structure, and the hollow portion formed between the double walls is evacuated or decompressed. Thereby, the heat insulation structure which suppresses that the heat supplied from the PTC heater 255 escapes outside is provided.

  Regarding other configurations, the second embodiment is the same as the first embodiment, and a detailed description thereof will be omitted.

  Energization of the PTC heater 255 is started when acceleration traveling is predicted in the flowchart of FIG. 5 (Yes in S10) and the vehicle 1 is preparing for acceleration traveling. When the PTC heater 255 is energized, the temperature and pressure of the gas enclosed in the gas chamber 53 increases due to the heat supplied from the PTC heater 255, that is, the energy capacity of the accumulator 50 increases. Then, an urging force is applied from the piston 54 to the oil storage chamber 52 side, and as a result, the pressure rises when the hydraulic oil is discharged. The energization of the PTC heater 255 is stopped in accordance with the stop of the hydraulic oil discharge.

  Note that the start timing of energization of the PTC heater 255 is preferably determined in consideration of the time to reach a desired temperature. For example, the energization may be started at the start of regeneration. Alternatively, energization may be performed only in the second half of regeneration.

  The configuration of each embodiment and each modification described above may be freely combined, modified, or omitted. For example, the accumulator 50 may be provided with both an electromagnet and a heating means. Further, the housing 51 may have a substantially rectangular tube shape. The electromagnet and the heating means may be operated by electric power supplied from another power source instead of the electric power stored in the capacitor 80. Furthermore, the vehicle 1 may be a hybrid vehicle including a motor generator.

  As described above, according to the present invention, it is possible to increase the amount of work that the hydraulic accumulator can do to the outside without increasing the size of the hydraulic accumulator. Therefore, this type of hydraulic accumulator is provided. There is a possibility of being suitably used in the field of manufacturing vehicles.

DESCRIPTION OF SYMBOLS 10 Motor generator 20 Inverter 30 Battery 40 Hydraulic pump motor 50 Accumulator 51 Housing 52 Oil storage chamber 53 Gas chamber 54 Piston 55 Coil 57 Permanent magnet 80 Capacitor 90 DC-DC converter 255 PTC heater

Claims (5)

A housing;
A partition member provided slidably in the housing,
An oil storage chamber for storing hydraulic oil supplied from a hydraulic pump motor by the partition member is a hydraulic accumulator separated from a gas chamber filled with gas,
An operation of biasing the partition member toward the oil storage chamber when the hydraulic oil is discharged from the oil storage chamber, and the partition member when the hydraulic oil is supplied from the hydraulic pump motor to the oil storage chamber An electric partition member urging means for urging the gas chamber toward the gas chamber is provided ,
The partition member urging means has a permanent magnet attached to the partition member, and two electromagnets provided on both the gas chamber side and the oil storage chamber side facing the permanent magnet,
As the partition member moves, when the magnetic force applied to the partition member from one of the two electromagnets exceeds the magnetic force applied to the partition member from the other, the energization state of the two electromagnets is switched. Hydraulic accumulator characterized by And when discharging the hydraulic oil from the each of the electromagnets provided in the gas chamber and the oil storage chamber, said oil storage chamber, reversed between when the working oil is supplied from the hydraulic pump motor to the oil storage chamber wherein the energization is performed to generate a magnetic field orientation, hydraulic accumulator according to claim 1. 3. The hydraulic accumulator according to claim 1, wherein the partition member urging unit further includes a heating unit that heats the gas in the gas chamber. 4. The hydraulic accumulator according to claim 3 , wherein the housing has a heat insulating structure. A motor generator that stores electric power in at least one of a battery and a capacitor by rotation of a drive wheel when hydraulic oil is supplied from the hydraulic pump motor to the oil storage chamber;
A hydraulic accumulator according to any one of claims 1 to 4 ,
The vehicle travel control device, wherein the partition member urging means is operated by electric power supplied from the capacitor.

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