JP2016196265A - Pressure accumulating device for vehicular regeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure high-safety when a failure occurs in a high-pressure accumulator.SOLUTION: In a pressure accumulating device for a vehicular regeneration system, the high-pressure accumulator 23 and a low-pressure reservoir 24 configure a double structure where the high-pressure accumulator 23 is provided inside the low-pressure reservoir 24.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a pressure accumulating device for a regenerative system for a vehicle, which is connected via an oil pump motor functioning as one of an oil pump and a hydraulic motor, and includes a high pressure accumulator that stores oil under pressure and a low pressure reservoir. It is.

  The basic structure of this type of regeneration system will be described with reference to FIG.

  FIG. 1 is a simplified drive system for an automobile equipped with a regenerative system ERS, and shows a state where the vehicle is running with the engine 1 as a power source (the power source may be a motor). An output shaft of the engine 1 is connected to drive wheels 5 via an engine clutch 2, a transmission 3, and a differential gear 4, and the drive wheels 5 are rotationally driven by the engine 1.

  The regenerative system ERS includes a coupling mechanism 11, a motor clutch 12, an oil pump motor 13, a high pressure accumulator 14, a low pressure reservoir 15, and the like. The rotation shaft of the oil pump motor 13 is connected to the output shaft to the drive wheels 5 via the motor clutch 12 and the connection mechanism 11. The motor clutch 12 is in a disconnected state.

  The oil pump motor 13 is connected between a high-pressure accumulator 14 and a low-pressure reservoir 15 that store oil in communication with each other. The oil pump motor 13 has both functions of an oil pump and a hydraulic motor, and can be used as either one of the devices. The high pressure accumulator 14 stores high pressure oil at a level of several hundred atmospheres, and the low pressure reservoir 15 stores low pressure oil at a level of several atmospheres to several tens of atmospheres.

  As shown in FIG. 2A, during braking such as downhill traveling, the engine clutch 2 is disengaged and the motor clutch 12 is connected, so that the power of the drive wheels 5 is input to the oil pump motor 13.

  Thereby, the oil pump motor 13 is driven as an oil pump, and the oil in the low pressure reservoir 15 is sent to the high pressure accumulator 14. As a result, the internal pressure of the high pressure accumulator 14 rises and higher pressure oil is accumulated (regeneration).

  As shown in FIG. 2 (b), when the vehicle starts, the oil in the high pressure accumulator 14 flows out toward the low pressure reservoir 15 with the motor clutch 12 engaged. The oil pump motor 13 is driven as a hydraulic motor by the discharge pressure of the oil, and the power is output to the drive wheels 5 (power running assist).

  An example of such a regeneration system is disclosed in Patent Document 1, for example.

JP 2012-111345 A

  However, the automobile shown in FIG. 1 has a problem that high safety cannot be ensured when an abnormality occurs in the high-pressure accumulator.

  This invention is made | formed in view of this point, The place made into the subject is to ensure high safety | security when abnormality generate | occur | produces in a high voltage | pressure accumulator.

  In order to solve the above problems, the present invention is characterized in that a high pressure accumulator is provided in a low pressure reservoir.

  Specifically, the present invention relates to a vehicle regenerative system including a high-pressure accumulator and a low-pressure reservoir that are connected via an oil pump motor that functions as one of an oil pump and a hydraulic motor and stores oil under pressure. The following solution was taken for the pressure accumulators.

  That is, the first invention is characterized in that the high pressure accumulator and the low pressure reservoir have a double structure in which the high pressure accumulator is provided in the low pressure reservoir.

  According to this, since the high pressure accumulator and the low pressure reservoir have a double structure in which the high pressure accumulator is provided in the low pressure reservoir, the low pressure reservoir is buffered when an abnormality occurs in the high pressure accumulator. It becomes a material and can ensure high safety.

  In a second aspect based on the first aspect, the high pressure accumulator is slidably disposed inside the container, and the interior of the container is divided into an oil chamber and a gas chamber in a sliding direction. The low pressure reservoir is slidably disposed along the container of the high pressure accumulator inside the container, and the oil chamber is disposed inside the container of the low pressure reservoir in a sliding direction. And a thermoelectric element that generates power using a temperature difference at a boundary portion between the gas chamber of the high-pressure accumulator and the gas chamber of the low-pressure reservoir. It is what.

  By the way, in the automobile shown in FIG. 1, energy loss occurs due to a temperature change of the high-pressure accumulator during regeneration.

  In FIG. 3, an example of the temperature change in the high voltage | pressure accumulator at the time of regeneration is shown. The broken line represents the change in vehicle speed, and the solid line represents the temperature change in the high pressure accumulator.

  When the vehicle speed is rapidly decelerated and oil is sent to the high pressure accumulator at once, the piston slides to the gas chamber side and the gas in the gas chamber is compressed (adiabatic compression). Thereby, the pressure and temperature of the gas rise, and the temperature of the high-pressure accumulator rises at a stretch by transferring the heat.

  Thereafter, the temperature of the high pressure accumulator gradually decreases due to heat dissipation and returns to room temperature. As a result, the energy stored in the high-pressure accumulator is reduced by the amount of heat energy that is lost due to heat dissipation than before the regeneration.

  For example, when the vehicle speed is suddenly reduced by 60 km / h, the temperature of the high pressure accumulator rises to near 80 ° C.

  Further, since oil flows out from the high pressure accumulator during power running, the temperature change of the high pressure accumulator also occurs at that time.

  That is, when oil flows out from the high-pressure accumulator at once, the piston slides to the oil chamber side and the gas in the gas chamber expands (adiabatic expansion). Thereby, since the pressure and temperature of gas fall, a high pressure accumulator is cooled. For example, the temperature of the high pressure accumulator can decrease from room temperature to −20 ° C.

  Here, according to the second aspect of the invention, the piston slides with the change in the amount of oil stored in the oil chambers of the high pressure accumulator and the low pressure reservoir, and the capacity of the gas chamber changes to large or small. When the gas sealed in the gas chamber is compressed or expanded all at once, the temperature of the gas chamber changes. Specifically, during regeneration, the temperature of the gas chamber of the high pressure accumulator rises above the environmental temperature, and the temperature of the gas chamber of the low pressure reservoir falls below the environmental temperature. During power running, the temperature of the gas chamber of the high pressure accumulator decreases below the ambient temperature, and the temperature of the gas chamber of the low pressure reservoir rises above the ambient temperature. Therefore, during regeneration and power running, the temperature difference between the high pressure accumulator and the gas chamber of the low pressure reservoir increases with temperature change.

  A thermoelectric element that generates power using a temperature difference is installed at the boundary between the gas chamber of the high pressure accumulator and the gas chamber of the low pressure reservoir. The accompanying thermal energy can be converted to electrical energy with high efficiency and recovered.

  According to a third invention, in the first invention, the high pressure accumulator is slidably disposed inside the container, and the interior of the container is divided into an oil chamber and a gas chamber in a sliding direction. The low pressure reservoir is slidably disposed along the container of the high pressure accumulator inside the container, and the oil chamber is disposed inside the container of the low pressure reservoir in a sliding direction. A piston partitioned into a gas chamber, a phase change material is stored in the gas chamber of the low pressure reservoir, and a heat exchanger at a boundary portion between the gas chamber of the high pressure accumulator and the gas chamber of the low pressure reservoir Is installed.

  By the way, in the automobile shown in FIG. 1, when the phase change material is stored in the gas chamber of the low pressure reservoir, the volume of the gas chamber of the low pressure reservoir is reduced by changing the phase change material to the liquid phase under pressure. In addition, the low pressure reservoir can be made compact.

  At this time, in the automobile shown in FIG. 1, the efficiency of the oil pump motor deteriorates.

  FIG. 4 shows an example of a Mollier diagram of the phase change substance stored in the gas chamber of the low pressure reservoir.

  When the vehicle speed is suddenly reduced and oil flows out from the low pressure reservoir at once, the piston slides to the oil chamber side and the phase change material in the gas chamber expands (adiabatic expansion. In the Mollier diagram shown in FIG. 4) , Point 1 → 2). As a result, the pressure and temperature of the phase change material decrease, and the heat is transferred to cool the low pressure reservoir.

  Thereafter, heat is transferred from the peripheral members to the low pressure reservoir. As a result, the phase change material in the gas chamber changes from the liquid phase to the gas phase at the same temperature (point 2 → 3 in the Mollier diagram shown in FIG. 4). This phase change depends on the amount of heat transfer.

  When the vehicle speed accelerates rapidly and oil is sent to the low pressure reservoir all at once, the piston slides to the gas chamber side and the phase change material in the gas chamber is compressed (adiabatic compression. Mollier wire shown in FIG. 4). In the figure, point 3 → 4). Thereby, since the pressure and temperature of the gas increase, the temperature of the low-pressure reservoir increases at a stretch. Note that the points 3 → 4 extend parallel to the isentropic line.

  Thereafter, heat is transferred from the low pressure reservoir to its peripheral members. As a result, the phase change material in the gas chamber changes from the gas phase to the liquid phase at the same temperature (point 4 → 5 in the Mollier diagram shown in FIG. 4). This phase change depends on the amount of heat transfer. This amount of heat transfer is substantially the same as the amount of heat transfer at point 2 → 3 because point 2 → 3 and point 4 → 5 have substantially the same temperature difference from the ambient temperature. Therefore, the phase change material in the gas chamber does not return to the point 1 state.

  Therefore, when regeneration and power running are repeated, the phase change material in the gas chamber is less likely to change into a liquid phase under pressure, preventing oil from flowing into and out of the high pressure accumulator and low pressure reservoir, Efficiency deteriorates.

  Here, according to the third aspect of the invention, the piston slides with the change in the amount of oil stored in the oil chambers of the high pressure accumulator and the low pressure reservoir, and the capacity of the gas chamber changes accordingly. When the phase change material sealed in the gas chamber of the low-pressure reservoir is compressed or expanded at once, the temperature of the gas chamber changes. Specifically, during regeneration, the temperature of the gas chamber of the high pressure accumulator rises above the environmental temperature, and the temperature of the gas chamber of the low pressure reservoir falls below the environmental temperature. During power running, the temperature of the gas chamber of the high pressure accumulator decreases below the ambient temperature, and the temperature of the gas chamber of the low pressure reservoir rises above the ambient temperature. Therefore, during regeneration and power running, the temperature difference between the high pressure accumulator and the gas chamber of the low pressure reservoir increases with temperature change.

  Since a heat exchanger is installed at the boundary between the gas chamber of the high pressure accumulator and the gas chamber of the low pressure reservoir, the gas in the gas chamber of the high pressure accumulator and the gas in the low pressure reservoir are passed through the heat exchanger. Heat is easily transferred between the phase change material of the chamber and the phase change of the phase change material is promoted. Therefore, it can suppress that the oil flows in and out of the high pressure accumulator and the low pressure reservoir, and the efficiency of the oil pump motor can be improved.

  A fourth invention is characterized in that, in the third invention, the phase change substance is substantially in a liquid phase state at an upper limit pressure of the low pressure reservoir under a use environment temperature.

  According to this, since the phase change substance is almost in the liquid phase state at the upper pressure limit of the low pressure reservoir under the use environment temperature, the gas chamber of the low pressure reservoir is used at the upper pressure limit of the low pressure reservoir under the use environment temperature. The volume is sufficiently reduced. Therefore, the low pressure reservoir can be sufficiently downsized.

  According to the present invention, when an abnormality occurs in the high pressure accumulator, high safety can be ensured.

It is the schematic which shows an example of the regeneration system of a motor vehicle. It is the schematic explaining the regeneration control of a motor vehicle. (A) has shown the state at the time of regeneration, and (b) has shown the state at the time of powering assistance. It is a graph which shows an example of the temperature change in the high pressure accumulator at the time of regeneration. It is a figure which shows an example of the Mollier diagram of the phase change substance stored in the gas chamber of a low pressure reservoir. It is the schematic which shows the outline | summary of the motor vehicle which mounted the regeneration system of Embodiment 1. FIG. It is a schematic sectional drawing which shows the structure of the electric power generation type accumulator of Embodiment 1. It is a figure explaining the principal part of a regeneration system. (A) has shown the connection state at the time of regeneration, (b) has shown the connection state at the time of power running, respectively. It is a graph which shows the relationship between the electric power obtained with a thermoelectric element, and an electric current. It is a graph which shows an example of the temperature change of the high voltage | pressure accumulator corresponding to the driving | running | working pattern of a motor vehicle. It is the schematic which shows the outline | summary of the motor vehicle which mounted the regeneration system of Embodiment 2. FIG. It is a schematic sectional drawing which shows the structure of the heat exchange type | mold accumulator of Embodiment 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its use.

(Embodiment 1)
(Configuration of regenerative system)
In FIG. 5, the outline | summary of the motor vehicle C which mounted the regeneration system ERS of this embodiment is shown. Since the basic configuration is the same as that of the automobile shown in FIG. 1, the same reference numerals are used for the configurations having the same functions, and the description thereof is omitted.

  The regenerative system ERS is further provided with a polarity switching circuit 20, a current adjustment circuit 21, a battery 22 (an example of a storage battery), and the like. The high pressure accumulator 23 and the low pressure reservoir 24 of the regenerative system ERS are partially different in structure from the high pressure accumulator 14 and the low pressure reservoir 15.

  The high pressure accumulator 23 and the low pressure reservoir 24 have an integrated dual structure in which the high pressure accumulator 23 is provided in the low pressure reservoir 24 (hereinafter, this structure is referred to as a power generation type accumulator 25).

  The high pressure accumulator 23 is provided with a cylindrical relatively small container 23a having pressure resistance and a disk-shaped piston 23b that freely slides inside the container 23a. The inside of the high pressure accumulator 23 is partitioned into an oil chamber 23c and a gas chamber 23d by a piston 23b.

  The low-pressure reservoir 24 is provided with a cylindrical relatively large container 24a having pressure resistance and an annular piston 24b that freely slides along the outer periphery of the container 23a of the high-pressure accumulator 23. ing. The inside of the low pressure reservoir 24 is partitioned into an oil chamber 24c and a gas chamber 24d by a piston 24b.

  As the capacity of the oil chambers 23c, 24c increases due to the sliding of the pistons 23b, 24b of the high pressure accumulator 23 and the low pressure reservoir 24, the capacity of the gas chambers 23d, 24d decreases accordingly, and the capacity of the oil chambers 23c, 24c decreases. The capacity of the gas chambers 23d and 24d increases accordingly.

  The oil chambers 23c and 24c of the high-pressure accumulator 23 and the low-pressure reservoir 24 are in communication with the oil pump motor 13, and oil flowing between the oil chambers 23c and 24c of the high-pressure accumulator 23 and the low-pressure reservoir 24 is stored. Yes. Therefore, the amount of oil stored in the oil chambers 23 c and 24 c varies according to the operation of the oil pump motor 13.

  On the other hand, the gas chambers 23d and 24d of the high pressure accumulator 23 and the low pressure reservoir 24 are sealed, and a certain amount of gas is stored therein.

  The power generation type accumulator 25 is electrically connected to the battery 22 and ACC (accessory power source). The polarity switching circuit 20 and the current adjustment circuit 21 are electrically connected between the power generation type accumulator 25, the battery 22 and the ACC, and are connected in series in this order from the power generation type accumulator 25 side.

  FIG. 6 shows a power generation type pressure accumulator 25. In the power generation type accumulator 25, a thermoelectric element 26 is installed at an end surface portion 23 e of the container 23 a of the high pressure accumulator 23 (a boundary portion between the gas chamber 23 d of the high pressure accumulator 23 and the gas chamber 24 d of the low pressure reservoir 24). .

  The thermoelectric element 26 has a function of generating power using a temperature difference. That is, an electromotive force is generated by a so-called Seebeck effect by using a thermoelectric element material that generates a potential difference by giving a temperature difference.

  Since the structure of the thermoelectric element 26 itself is known, detailed description thereof is omitted here. However, in the case of this regenerative system ERS, the thermoelectric element material is preferably a bismuth-tellurium-based material containing bismuth and tellurium as elements.

  As will be described later, the thermoelectric element 26 is used near normal temperature in both the minus temperature range and the plus temperature range, such as −20 ° C. and 80 ° C. On the other hand, bismuth-tellurium-based thermoelectric element materials are suitable for this temperature range, and thus can exhibit excellent power generation performance.

  The thermoelectric element 26 is installed such that one of a pair of working surfaces receiving the temperature difference is directed to the gas chamber 23 d of the high pressure accumulator 23 and the other working surface is directed to the gas chamber 24 d of the low pressure reservoir 24. The working surfaces facing the gas chambers 23d and 24d may not be exposed to the gas chambers 23d and 24d, but in this case, they are preferably arranged in the vicinity of the gas chambers 23d and 24d.

  The pair of lead-out wirings p1 and p2 that output the electromotive force generated in the thermoelectric element 26 is outside the power generation type accumulator 25 through a through hole (not shown) opened in the end surface portion 24e of the container 24a of the low-pressure reservoir 24. Has been derived. The through hole through which the lead-out wirings p1 and p2 are inserted is sealed by a sealing member (not shown). The lead-out wirings p1 and p2 may be electrically connected to the outside of the power generation type pressure accumulator 25 via a relay terminal.

  As shown in FIG. 7, the lead-out wirings p <b> 1 and p <b> 2 drawn from the power generation type pressure accumulator 25 are connected to the polarity switching circuit 20.

  Specifically, each of the lead-out wirings p1 and p2 is connected to the pair of relay wirings h1 and h2 by the polarity switching circuit 20 so that they can be switched alternately.

  In the polarity switching circuit 20 of the present embodiment, two switching terminals including a regeneration side terminal 20a and a power running side terminal 20b are provided, and each of the lead-out wirings p1 and p2 branches to regenerate one of the switching terminals. The side terminal 20a is connected to the power running side terminal 20b of the other switching terminal. Each relay wiring h1, h2 is connected to the switch terminal 20c of each switching terminal, and each switch terminal 20c switches electrical connection between the regeneration side terminal 20a and the power running side terminal 20b of each switching terminal.

  (A) of FIG. 7 represents the connection state at the time of regeneration, and each switch terminal 20c is connected to each regeneration side terminal 20a. (B) of FIG. 7 represents the connection state at the time of power running, and each switch terminal 20c is connected to each power running side terminal 20b.

  In this way, the polarity switching circuit 20 alternately switches the connection between the pair of lead-out wirings p1 and p2 and the pair of relay wirings h1 and h2 during regeneration and powering. The polarity of electric power is reversed between regeneration and power running.

  The pair of relay wirings h <b> 1 and h <b> 2 are connected to the current adjustment circuit 21. The current adjustment circuit 21 has a function of performing maximum power point tracking control. In the maximum power point tracking control, the electrical operating point is adjusted so that the maximum power generation amount can be obtained with respect to the electromotive force of the changing thermoelectric element 26.

  FIG. 8 shows a relationship between electric power and current obtained by the thermoelectric element 26. In the thermoelectric element 26, the electric resistance increases as the current flowing through the thermoelectric element material increases, so that there is a peak in the obtained electric power. Therefore, in this current adjustment circuit 21, maximum power point tracking control is performed so that the thermoelectric element 26 operates at the maximum power point indicating the peak.

  The current adjustment circuit 21 is connected to the battery 22 and the ACC through the power transmission line k. The electromotive force whose output is adjusted by the current adjustment circuit 21 is transmitted to the battery 22 and the ACC through the transmission line k.

(Operation of regenerative system ERS)
FIG. 9 shows an example of a temperature change of the high-pressure accumulator 23 of the power generation-type accumulator 25 corresponding to the traveling pattern of the automobile C. A broken line represents a change in vehicle speed, and a solid line represents a temperature change in the high pressure accumulator 23.

  When the vehicle speed is suddenly reduced and regeneration is performed, oil is sent to the high pressure accumulator 23 at a stretch, so that the pressure in the oil chamber 23c of the high pressure accumulator 23 suddenly rises and the piston 23b slides toward the gas chamber 23d. The gas in the gas chamber 23d is adiabatically compressed. When the gas in the gas chamber 23d is adiabatically compressed, the temperature of the gas chamber 23d rises from normal temperature (normal temperature) at a stretch, and the temperature of the high pressure accumulator 23 rises accordingly.

On the other hand, when the regeneration is performed, the oil flows out from the low pressure reservoir 24 all at once, so that the pressure in the oil chamber 24c of the low pressure reservoir 24 suddenly drops and the piston 24b slides toward the oil chamber 24c, and the gas in the gas chamber 24d Expands adiabatically. When the gas in the gas chamber 24d is adiabatically expanded, the temperature of the gas chamber 24d is reduced from room temperature all at once, and the temperature of the low pressure reservoir 24 is also reduced accordingly. The gas chamber 23d of the high pressure accumulator 23 and the gas chamber 24d of the low pressure reservoir 24 Since the thermoelectric element 26 is installed at the boundary portion of the above, with one of its working surfaces facing the gas chamber 23d of the high pressure accumulator 23 and the other working surface facing the gas chamber 24d of the low pressure reservoir 24, these An electromotive force is generated in the thermoelectric element 26 due to the temperature difference between the working surfaces.

  Therefore, since the thermal energy lost by heat radiation can be recovered by the thermoelectric element 26, the energy recovery efficiency can be improved.

  The electromotive force generated in the thermoelectric element 26 is output from the power generation type accumulator 25, adjusted by the current adjustment circuit 21, and then transmitted to the battery 22 and the ACC.

  Although the temperature change of the thermoelectric element 26 is large, since the maximum power point tracking control is performed by the current adjustment circuit 21, energy loss during power generation can be effectively suppressed.

  When the vehicle speed is suddenly accelerated and powering is performed, the oil flows out from the high pressure accumulator 23 at a stretch. Therefore, the pressure in the oil chamber 23c of the high pressure accumulator 23 suddenly decreases and the piston 23b slides toward the oil chamber 23c. Then, the gas in the gas chamber 23d expands adiabatically. When the gas in the gas chamber 23d is adiabatically expanded, the temperature of the gas chamber 23d is lowered from room temperature at a stretch, and the temperature of the high pressure accumulator 23 is also lowered accordingly.

  On the other hand, when power running is performed, the oil is sent to the low pressure reservoir 24 at a stretch, so that the pressure in the oil chamber 24c of the low pressure reservoir 24 suddenly rises, the piston 24b slides toward the gas chamber 24d, and the gas in the gas chamber 24d is Adiabatic compression. When the gas in the gas chamber 24d is adiabatically compressed, the temperature of the gas chamber 24d rises from room temperature all at once, and accordingly, the temperature of the low-pressure reservoir 24 also rises.

  At the boundary between the gas chamber 23d of the high-pressure accumulator 23 and the gas chamber 24d of the low-pressure reservoir 24, the thermoelectric element 26 has one of its working surfaces facing the gas chamber 23d of the high-pressure accumulator 23 and the other working surface. Since it is installed toward the gas chamber 24d of the low-pressure reservoir 24, an electromotive force is generated in the thermoelectric element 26 due to the temperature difference between these working surfaces.

  At this time, since the temperature acting on the working surface of the thermoelectric element 26 is opposite to that during regeneration, the polarity of the electromotive force generated in the thermoelectric element 26 is also opposite.

  In contrast, in the regenerative system ERS, the polarity switching circuit 20 switches the connection state between the pair of lead-out wirings p1 and p2 and the pair of relay wirings h1 and h2, and the polarity of the electromotive force output from the thermoelectric element 26 is changed. It is controlled so as to be reversed between regeneration and power running.

  Thereby, the polarity of the electromotive force output to the current adjustment circuit 21 is always constant. Therefore, energy can be recovered using the temperature change generated in the power generation type pressure accumulator 25 both during power running and during regeneration, so that energy recovery efficiency can be improved.

-Effect-
As described above, according to the present embodiment, the high pressure accumulator 23 and the low pressure reservoir 24 have a double structure in which the high pressure accumulator 23 is provided in the low pressure reservoir 24. When this occurs, the low-pressure reservoir 24 becomes a cushioning material, and high safety can be ensured.

  Further, the pistons 23b and 24b slide in accordance with changes in the amount of oil stored in the oil chambers 23c and 24c of the high-pressure accumulator 23 and the low-pressure reservoir 24, and the capacities of the gas chambers 23d and 24d change to large or small. When the gas sealed in the gas chambers 23d and 24d is compressed or expanded all at once, the temperature of the gas chambers 23d and 24d changes. Specifically, during regeneration, the temperature of the gas chamber 23d of the high pressure accumulator 23 rises above the environmental temperature, and the temperature of the gas chamber 24d of the low pressure reservoir 24 falls below the environmental temperature. During power running, the temperature of the gas chamber 23d of the high pressure accumulator 23 is lower than the environmental temperature, and the temperature of the gas chamber 24d of the low pressure reservoir 24 is higher than the environmental temperature. Accordingly, during regeneration and power running, the temperature difference between the high pressure accumulator 23 and the gas chambers 23d and 24d of the low pressure reservoir 24 increases with temperature.

  Since a thermoelectric element 26 that generates power using a temperature difference is installed at the boundary between the gas chamber 23d of the high pressure accumulator 23 and the gas chamber 24d of the low pressure reservoir 24, the high pressure accumulator 23 and the low pressure reservoir The thermal energy accompanying the temperature change of 24 gases can be converted into electric energy with high efficiency and recovered.

  The power generation type pressure accumulator 25 is not limited to the above-described embodiment, and includes various other configurations.

  For example, power generation may be performed only during either regeneration or power running. In that case, since the polarity switching circuit 20 can be omitted, there is an advantage that the system can be simplified.

(Embodiment 2)
Although this embodiment differs from Embodiment 1 in an accumulator etc., it is the structure similar to Embodiment 1 about another point. Therefore, in the following description, a duplicate description of the same components as those of the first embodiment may be omitted.

(Configuration of regenerative system)
In FIG. 10, the outline | summary of the motor vehicle C which mounted the regeneration system ERS of this embodiment is shown. Since the basic configuration is the same as that of the automobile shown in FIG. 1, the same reference numerals are used for the configurations having the same functions, and the description thereof is omitted.

  The high pressure accumulator 23 and the low pressure reservoir 24 of the regenerative system ERS are partially different in structure from the high pressure accumulator 14 and the low pressure reservoir 15.

  The high pressure accumulator 23 and the low pressure reservoir 24 have an integrated double structure in which the high pressure accumulator 23 is provided in the low pressure reservoir 24 (hereinafter, this structure is referred to as a heat exchange type accumulator 27).

  The gas chamber 24d of the low-pressure reservoir 24 stores a gas-liquid phase change substance therein.

  The gas-liquid phase change substance is substantially in the liquid phase state at the upper limit pressure (for example, 10 MPa) of the low pressure reservoir 24 under the use environment temperature (for example, 30 ° C.). For example, the gas-liquid phase change material is R134a refrigerant.

  FIG. 11 shows a heat exchange type pressure accumulator 27. In this heat exchange type accumulator 27, a heat exchanger 28 is installed at an end surface portion 23e of the container 23a of the high pressure accumulator 23 (a boundary portion between the gas chamber 23d of the high pressure accumulator 23 and the gas chamber 24d of the low pressure reservoir 24). ing.

  The heat exchanger 28 has a function of exchanging heat between the gas stored in the gas chamber 23 d of the high pressure accumulator 23 and the gas-liquid phase change material stored in the gas chamber 24 d of the low pressure reservoir 24.

  Since the structure of the heat exchanger 28 itself is known, detailed description thereof is omitted here.

  The heat exchanger 28 is installed with one surface facing the gas chamber 23 d of the high pressure accumulator 23 and the other surface facing the gas chamber 24 d of the low pressure reservoir 24.

(Operation of regenerative system ERS)
As shown in FIG. 9, when the vehicle speed is rapidly decelerated and regeneration is performed, the temperature of the gas chamber 23d of the high-pressure accumulator 23 rises at a stretch from the normal temperature as in the case of the first embodiment. The temperature of the pressure accumulator 23 also increases.

  On the other hand, when regeneration is performed, as in the case of the first embodiment, the temperature of the gas chamber 24d of the low-pressure reservoir 24 is reduced from room temperature all at once, and accordingly, the temperature of the low-pressure reservoir 24 is also reduced.

  Since the heat exchanger 28 is installed at the boundary between the gas chamber 23d of the high pressure accumulator 23 and the gas chamber 24d of the low pressure reservoir 24, the heat exchanger 28 stores the heat chamber 28d in the gas chamber 23d of the high pressure accumulator 23. The hot gas and the low-temperature (liquid phase state) gas-liquid phase change substance stored in the gas chamber 24d of the low-pressure reservoir 24 exchange heat.

  Accordingly, heat can be transferred from the high-temperature gas stored in the gas chamber 23d of the high-pressure accumulator 23 to the low-temperature gas-liquid phase change substance stored in the gas chamber 24d of the low-pressure reservoir 24. The phase change from the liquid phase to the gas phase of the gas-liquid phase change substance stored in the gas chamber 24d can be promoted.

  When the vehicle speed is accelerated and powering is performed, the temperature of the gas chamber 23d of the high-pressure accumulator 23 is reduced from normal temperature at the same time as in the first embodiment, and the temperature of the high-pressure accumulator 23 is also lowered accordingly. To do.

  On the other hand, when power running is performed, the temperature of the gas chamber 24d of the low-pressure reservoir 24 rises from room temperature all at once, and the temperature of the low-pressure reservoir 24 rises accordingly.

  Since the heat exchanger 28 is installed at the boundary between the gas chamber 23d of the high pressure accumulator 23 and the gas chamber 24d of the low pressure reservoir 24, the heat exchanger 28 stores the heat chamber 28d in the gas chamber 23d of the high pressure accumulator 23. Heat exchange occurs between the low-temperature gas and the high-temperature (gas phase) gas-liquid phase change substance stored in the gas chamber 24d of the low-pressure reservoir 24.

  Accordingly, heat can be transferred from the high-temperature gas-liquid phase change substance stored in the gas chamber 24d of the low-pressure reservoir 24 to the low-temperature gas-liquid phase change substance stored in the gas chamber 23d of the high-pressure accumulator 23. The phase change of the gas-liquid phase change substance stored in the gas chamber 24d of the low pressure reservoir 24 from the gas phase to the liquid phase can be promoted.

-Effect-
As described above, according to the present embodiment, the high pressure accumulator 23 and the low pressure reservoir 24 have a double structure in which the high pressure accumulator 23 is provided in the low pressure reservoir 24. When this occurs, the low-pressure reservoir 24 becomes a cushioning material, and high safety can be ensured.

  Further, the pistons 23b and 24b slide in accordance with changes in the amount of oil stored in the oil chambers 23c and 24c of the high-pressure accumulator 23 and the low-pressure reservoir 24, and the capacities of the gas chambers 23d and 24d change to large or small. When the gas-liquid phase change substance sealed in the gas chamber 24d of the low-pressure reservoir 24 is compressed or expanded all at once, the temperatures of the gas chambers 23d and 24d change. Specifically, during regeneration, the temperature of the gas chamber 23d of the high pressure accumulator 23 rises above the environmental temperature, and the temperature of the gas chamber 24d of the low pressure reservoir 24 falls below the environmental temperature. During power running, the temperature of the gas chamber 23d of the high pressure accumulator 23 is lower than the environmental temperature, and the temperature of the gas chamber 24d of the low pressure reservoir 24 is higher than the environmental temperature. Accordingly, during regeneration and power running, the temperature difference between the high pressure accumulator 23 and the gas chambers 23d and 24d of the low pressure reservoir 24 increases with temperature.

  And since the heat exchanger 28 is installed in the boundary part of the gas chamber 23d of the high pressure accumulator 23 and the gas chamber 24d of the low pressure reservoir 24, the gas chamber of the high pressure accumulator 23 is provided via the heat exchanger 28. Heat easily moves between the gas 23d and the gas-liquid phase change substance in the gas chamber 24d of the low-pressure reservoir 24, and the phase change of the gas-liquid phase change substance is promoted. Therefore, it can suppress that the oil flows in and out of the high-pressure accumulator 23 and the low-pressure reservoir 24, and the efficiency of the oil pump motor 13 can be improved.

  In addition, since the gas-liquid phase change material is at the upper limit pressure of the low pressure reservoir 24 under the use environment temperature and is almost in the liquid phase state, the gas in the low pressure reservoir 24 is used at the upper limit pressure of the low pressure reservoir 24 under the use environment temperature. The volume of the chamber 24d is sufficiently reduced. Therefore, the low pressure reservoir 24 can be sufficiently downsized.

(Other embodiments)
The pressure accumulator is not limited to the above-described embodiments, and includes various other configurations.

  For example, the thermoelectric element 26 and the heat exchanger 28 are not necessarily installed in the pressure accumulator.

  As described above, the accumulator of the vehicle regenerative system according to the present invention can be applied to uses and the like that need to ensure high safety when an abnormality occurs in the high-pressure accumulator.

13 Oil pump motor 23 High pressure accumulator 23a Container 23b Piston 23c Oil chamber 23d Gas chamber 23e End surface (boundary part of gas chamber of high pressure accumulator and gas chamber of low pressure reservoir)
24 Low pressure reservoir 24a Container 24b Piston 24c Oil chamber 24d Gas chamber 25 Power generation type accumulator 26 Thermoelectric element 27 Heat exchange accumulator 28 Heat exchanger

Claims (4)

A pressure accumulator for a vehicle regenerative system that is connected via an oil pump motor that functions as one of an oil pump and a hydraulic motor, and that includes a high pressure accumulator that stores oil under pressure and a low pressure reservoir,
The high pressure accumulator and the low pressure reservoir have a double structure in which the high pressure accumulator is provided in the low pressure reservoir. The pressure accumulator according to claim 1, wherein
The high-pressure accumulator has a container and a piston that is slidably disposed inside the container and divides the interior of the container into an oil chamber and a gas chamber in a sliding direction.
The low-pressure reservoir is slidably disposed along the container of the high-pressure accumulator inside the container, and a piston that divides the inside of the container of the low-pressure reservoir into an oil chamber and a gas chamber in a sliding direction. And
A pressure accumulating apparatus, wherein a thermoelectric element that generates power using a temperature difference is installed at a boundary portion between the gas chamber of the high pressure accumulator and the gas chamber of the low pressure reservoir. The pressure accumulator according to claim 1, wherein
The high-pressure accumulator has a container and a piston that is slidably disposed inside the container and divides the interior of the container into an oil chamber and a gas chamber in a sliding direction.
The low-pressure reservoir is slidably disposed along the container of the high-pressure accumulator inside the container, and a piston that divides the inside of the container of the low-pressure reservoir into an oil chamber and a gas chamber in a sliding direction. And
Phase change material is stored in the gas chamber of the low pressure reservoir,
A pressure accumulator characterized in that a heat exchanger is installed at a boundary portion between the gas chamber of the high pressure accumulator and the gas chamber of the low pressure reservoir. The pressure accumulator according to claim 3,
The pressure-accumulation apparatus according to claim 1, wherein the phase-change substance is substantially in a liquid phase state at an upper limit pressure of the low-pressure reservoir at a use environment temperature.

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