JP6901323B2 - Heat pump device - Google Patents

Description

The present invention relates to a configuration in a heat pump device driven by an engine that maintains the amount of engine oil stored in the oil pan of the engine.

Conventionally, an engine-driven heat pump device in which a compressor for compressing a refrigerant is driven by an engine has been known. In this engine-driven heat pump device, an oil tank is provided separately from the oil pan provided in the engine, and engine oil is supplied from the oil tank by a supply device such as a pump according to the amount of engine oil in the oil pan. Supply to bread. Patent Document 1 discloses an engine oil replenishing device that supplies engine oil in an oil pan.

The engine oil replenishing device of Patent Document 1 has a first oil tank that communicates with the oil pan of the engine and whose internal oil level synchronizes with the rise and fall of the oil level position in the oil pan, and an engine replenished from the outside. A second oil tank for storing oil is provided, and an engine oil return path for communicating the first oil tank and the second oil tank is provided, and the lower end of the opening of the engine oil return path is in the oil pan. The configuration is such that it is provided at a position that is the upper limit level of the engine oil to be stored. Patent Document 1 states that the amount of engine oil stored in the oil pan of an engine can be easily maintained at an appropriate amount by this configuration.

Japanese Patent No. 4425307

However, in the configuration of Patent Document 1, it is necessary to provide a first oil tank and a second oil tank, and the lower end of the opening of the engine oil return path in the first oil tank is set to the upper limit of the engine oil in the oil pan. Since it had to be positioned at the level, the structure of the oil tank became complicated, and there was room for improvement in terms of labor during manufacturing, stabilization of quality, and cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat pump device capable of easily controlling the engine oil storage amount of an oil pan with a simple configuration.

Means and effects to solve problems

The problem to be solved by the present invention is as described above, and next, the means for solving this problem and its effect will be described.

According to the viewpoint of the present invention, the following configurations are provided for the heat pump device driven by the engine. That is, this heat pump device includes an oil tank, a pump, an oil return pipe, and an air flow pipe. The oil tank stores engine oil to be supplied to the oil pan of the engine. The pump supplies engine oil from the oil tank to the oil pan. The oil return pipe returns the engine oil of the oil pan to the oil tank. The air flow pipe allows air to flow between the internal space of the engine and the internal space of the oil tank. The height of the first opening, which is the opening formed by the oil return pipe in the internal space of the oil pan, is higher than the height of the second opening, which is the opening formed by the oil return pipe in the internal space of the oil tank. It's getting low. The third opening, which is the opening formed by the air flow pipe in the internal space of the oil tank, is arranged directly above the second opening. The contour of the third opening is entirely included inside the contour of the second opening when viewed in a plan view.

As a result of supplying engine oil to the oil pan, when the oil level in the oil pan rises and exceeds the height of the first opening in the oil pan, the engine oil enters the oil return pipe from the first opening. Inflow. When the oil level in the oil pan rises further and exceeds the height of the second opening in the oil tank, the amount of engine oil in the oil return pipe overflows from the second opening. It is automatically returned to the oil tank. Therefore, if the pump is sufficiently driven, the oil level height in the oil pan can be surely raised to the height of the second opening and can be maintained at the height of the second opening. As a result, the oil level height in the oil pan can be easily controlled. Further, since the engine oil of the oil pan is returned by the oil return pipe, it is possible to reduce the labor and cost at the time of manufacturing. Even if the engine oil is pumped from the oil pan by the lubrication pump, lubricates each part of the engine and returns to the oil pan, even if the engine oil is mixed inside the pressure equalizing pipe and returned to the oil tank, the engine oil Can be received by the oil return pipe. As a result, the engine oil can be supplied to the oil pan via the oil return pipe, and the oil level in the oil pan can be prevented from dropping.

In the heat pump device, the height of the first opening is preferably lower than the lower limit height of the oil level of the engine oil in the oil pan defined for the engine.

This allows the engine oil to be returned to the oil tank from a sufficiently low position in the oil pan via the oil return pipe. As a result, the amount of engine oil that stays at the bottom of the oil pan can be reduced, and the cleanliness of the engine oil can be improved.

In the heat pump device, it is preferable that the second opening of the oil return pipe is arranged at a height substantially coincide with the oil level upper limit height of the engine oil in the oil pan defined for the engine.

As a result, it becomes easy to maintain the oil level of the engine oil in the oil pan high, so that deterioration of the engine oil can be suppressed.

In the heat pump device, the oil return pipe preferably has a portion that passes through the side wall of the oil tank and a portion that bends upward inside the oil tank.

As a result, the shape of the oil return pipe becomes simple, so that the oil return pipe can be easily formed.

In the heat pump device, it is preferable that the oil return pipe is formed with a passage expanding portion in which the internal passage becomes wider as it approaches the second opening.

Thereby, for example, even when a thin pipe is used as the oil return pipe, the engine oil falling from the third opening of the pressure equalizing pipe can be reliably received.

The perspective view which shows the heat pump apparatus which concerns on one Embodiment of this invention. The schematic which shows the refrigerant circuit of a heat pump apparatus. The rear view which shows the heat pump apparatus. A front view showing an engine and an oil supply device arranged inside a housing. Schematic diagram of the engine and oil supply device. (A) A perspective view showing a positional relationship between an oil return pipe and a pressure equalizing pipe inside an oil tank. (B) The figure explaining the positional relationship between the openings of a pressure equalizing pipe and an oil return pipe in a plan view. The perspective view which shows the heat pump apparatus of the 1st modification. The schematic diagram which shows the heat pump apparatus of the 2nd modification.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a heat pump device 1 according to an embodiment of the present invention. FIG. 2 is a schematic view showing a refrigerant circuit of the heat pump device 1.

The heat pump device 1 shown in FIG. 1 is configured as a heat pump chiller capable of supplying cold heat or hot heat to the external device 90. The heat pump device 1 and the external device 90 are connected by a pair of circulating liquid pipes 91. The heat pump device 1 cools or heats the circulating liquid circulating with the external device 90 by heat exchange using a refrigerant.

In the present specification, the refrigerant means a medium that carries heat, and is a concept including a case where it is used for cooling the circulating liquid introduced into the heat pump device 1 and a case where it is used for heating the circulating liquid. Is. When the circulating fluid is cooled in the heat pump device 1, cold heat is supplied to the external device 90, and when the circulating fluid is heated in the heat pump device 1, hot heat is supplied to the external device 90. As the circulating fluid, for example, water can be used, but the circulating fluid is not limited to this.

As shown in FIG. 2, the heat pump device 1 includes an engine 11, a compressor 12, an accumulator 13, an oil separator 14, a four-way valve 15, an outside air-refrigerant heat exchanger 16, a bridge circuit 17, and a receiver 18. The expansion valve 19 and the circulating liquid-refrigerant heat exchanger 20 are provided. These devices are arranged inside the housing 2 shown in FIG.

The engine 11 is a drive source of the compressor 12, and is configured as a gas engine using gas as fuel. However, the engine 11 may be configured to use a fuel other than gas (for example, heavy oil, kerosene, etc.).

The compressor 12 is driven by the engine 11, sucks the refrigerant from the accumulator 13, compresses it, and discharges it toward the oil separator 14. By this pumping, the refrigerant can be circulated in the refrigerant circuit including the outside air-refrigerant heat exchanger 16 and the circulating liquid-refrigerant heat exchanger 20.

The accumulator 13 separates the refrigerant into a liquid and a gas, and supplies the refrigerant in a gaseous state to the compressor 12. This prevents liquid compression by the compressor 12. When the compressor 12 is driven, the refrigerant in a gas state is sucked from the accumulator 13. The refrigerant is adiabatically compressed by the compressor 12 to become a superheated state, and is supplied to the oil separator 14 in the form of a high-temperature and high-pressure gas.

The oil separator 14 separates the lubricating oil for the compressor 12 from the gaseous refrigerant. The separated lubricating oil is returned to the compressor 12 by the oil return circuit (not shown). The gaseous refrigerant from which the lubricating oil is separated by the oil separator 14 is supplied to the four-way valve 15.

The four-way valve 15 is configured as a switching valve having four ports. The four-way valve 15 can be switched between a cooling operation for cooling the circulating fluid and a heating operation for heating the circulating fluid so that the supply destination of the refrigerant is different.

The outside air-refrigerant heat exchanger 16 exchanges heat between the outside air and the refrigerant. As the outside air-refrigerant heat exchanger 16, for example, a plate fin tube type heat exchanger can be used.

The bridge circuit 17 includes four check valves, and can automatically switch the direction in which the refrigerant flows between the cooling operation and the heating operation.

The receiver 18 can temporarily store the refrigerant whose temperature has dropped due to heat exchange between the outside air-refrigerant heat exchanger 16 or the circulating liquid-refrigerant heat exchanger 20 and which has become liquid.

The expansion valve 19 expands the refrigerant compressed by the compressor 12.

The circulating liquid-refrigerant heat exchanger 20 exchanges heat between the circulating liquid supplied from the external device 90 and the refrigerant. As the circulating liquid-refrigerant heat exchanger 20, for example, a plate type heat exchanger can be used.

First, the flow of the refrigerant during the cooling operation will be described.

When cooling the circulating fluid, the four-way valve 15 supplies high-temperature and high-temperature gaseous refrigerant from the oil separator 14 to the outside air-refrigerant heat exchanger 16 by connecting the ports as shown by the solid line in FIG. To do. In the outside air-refrigerant heat exchanger 16, heat exchange is performed between the outside air and the high-temperature refrigerant, whereby the refrigerant condenses and changes to a high-pressure liquid. Therefore, at this time, the outside air-refrigerant heat exchanger 16 functions as a condenser.

The refrigerant that has been heat-exchanged by the outside air-refrigerant heat exchanger 16 and has become liquid is supplied to the receiver 18 after passing through the bridge circuit 17.

The high-pressure liquid refrigerant emitted from the receiver 18 is depressurized by passing through the expansion valve 19, and becomes a low-temperature, low-pressure mist (gas-liquid mixed state). After that, the refrigerant is supplied to the circulating liquid-refrigerant heat exchanger 20 via the bridge circuit 17. In the circulating liquid-refrigerant heat exchanger 20, heat exchange is performed between the circulating liquid and the low-temperature refrigerant, whereby the circulating liquid can be cooled. Along with this heat exchange, the mist-like portion of the refrigerant evaporates and changes to a low-temperature, low-pressure gaseous state. Therefore, at this time, the circulating liquid-refrigerant heat exchanger 20 functions as an evaporator.

After that, the refrigerant is returned to the accumulator 13 via the four-way valve 15.

Next, the flow of the refrigerant during the heating operation will be described.

When heating the circulating fluid, the four-way valve 15 connects the ports as shown by the broken line in FIG. 2 to transfer a high-temperature and high-temperature gaseous refrigerant from the oil separator 14 to the circulating fluid-refrigerant heat exchanger 20. Supply. In the circulating liquid-refrigerant heat exchanger 20, heat exchange is performed between the circulating liquid and the high-temperature refrigerant, whereby the circulating liquid can be heated. As a result, the refrigerant condenses and changes to a low-temperature, high-pressure liquid. Therefore, at this time, the circulating liquid-refrigerant heat exchanger 20 functions as a condenser.

The refrigerant that has been liquefied by heat exchange in the circulating liquid-refrigerant heat exchanger 20 is supplied to the receiver 18 via the bridge circuit 17.

The low-temperature, high-pressure liquid refrigerant emitted from the receiver 18 is depressurized by passing through the expansion valve 19, and becomes a low-temperature, low-pressure mist (gas-liquid mixed state). After that, the refrigerant is supplied to the outside air-refrigerant heat exchanger 16 via the bridge circuit 17. In the outside air-refrigerant heat exchanger 16, heat exchange is performed between the outside air and the low-temperature refrigerant. Along with this heat exchange, the mist-like portion of the refrigerant evaporates and changes to a low-temperature, low-pressure gaseous state. Therefore, at this time, the outside air-refrigerant heat exchanger 16 functions as an evaporator.

After that, the refrigerant is returned to the accumulator 13 via the four-way valve 15.

Next, the oil supply device 4 provided in the heat pump device 1 for supplying engine oil to the engine 11 will be described. FIG. 3 is a rear view showing the heat pump device 1. FIG. 4 is a front view showing the engine 11 and the oil supply device 4 arranged inside the housing 2. FIG. 5 is a schematic view of the engine 11 and the oil supply device 4. FIG. 6A is a perspective view showing the positional relationship between the oil return pipe 30 and the pressure equalizing pipe 40 inside the oil tank 22. FIG. 6B is a diagram for explaining the positional relationship between the openings of the pressure equalizing pipe 40 and the oil return pipe 30 in a plan view.

First, the configuration of the engine 11 will be briefly described. As shown in FIG. 3, the engine 11 includes a cylinder block 11a and an oil pan 11b.

A plurality of cylinders for accommodating pistons are formed in the cylinder block 11a.

The oil pan 11b stores engine oil that lubricates the engine 11. The oil pan 11b is provided at the lower part of the engine 11. The engine oil stored in the oil pan 11b is sucked by a lubrication pump (not shown) provided in the engine 11 and then supplied to each part of the engine 11, lubricated the engine 11, and then returned to the oil pan 11b and stored. Lubrication.

As shown in FIG. 3, the oil supply device 4 includes an oil tank 22, an oil supply pipe 23, an oil pump (pump) 24, an oil return pipe 30, and a pressure equalizing pipe 40.

The oil tank 22 is a tank for storing engine oil for supplying the oil pan 11b. The oil tank 22 functions as a secondary oil reservoir for the oil pan as the main oil reservoir of the engine 11. As shown in FIG. 4, the oil tank 22 is formed in a hollow rectangular parallelepiped shape, and is provided outside the engine 11, specifically, at a position lateral to the oil pan 11b. An oil filler port 25 is provided in the upper part of the oil tank 22, and engine oil can be replenished from the outside. The oil tank 22 can substantially increase the amount of engine oil that can be stored in the engine 11.

The oil tank 22 communicates with the oil pan 11b via the oil supply pipe 23 and the oil return pipe 30.

The oil supply pipe 23 is configured as an elongated hollow pipe. As shown in FIG. 4, the end portion of the oil supply pipe 23 on one side in the longitudinal direction is located near the inner bottom surface of the oil tank 22. The oil supply pipe 23 has a portion that extends upward from the end portion and penetrates the upper surface of the oil tank 22 in the vertical direction, and a portion that extends in the horizontal direction after being bent above the oil tank 22.

An oil filter 26 and an oil pump 24 are provided in the middle portion of the oil supply pipe 23 in the longitudinal direction (a portion located above the oil tank 22). In the oil supply path formed by the oil supply pipe 23, the oil filter 26 is provided on the upstream side of the oil pump 24.

The oil supply pipe 23 extends from the portion where the oil pump 24 is arranged so as to pass through the space between the oil tank 22 and the engine 11 while appropriately bending, and is laterally connected to the bottom of the oil pan 11b. Has.

The oil pump 24 is driven by, for example, an electric motor or the like. By driving the oil pump 24, the engine oil in the oil tank 22 is sucked into the oil supply pipe 23, passes through the oil filter 26, and is pressure-fed into the oil pan 11b.

The oil return pipe 30 is configured as an elongated hollow pipe. Specifically, the oil return pipe 30 is formed by bending a round pipe as appropriate.

One end of the oil return pipe 30 in the longitudinal direction is connected to the lower part of the oil pan 11b as shown in FIGS. 4 and 5 to form a first opening 31 leading to the internal space of the oil pan 11b. .. The first opening 31 is arranged sideways on the inner wall of the oil pan 11b. Further, the height at which the first opening 31 is arranged inside the oil pan 11b is lower than the lower limit height OL of the oil level defined for the engine 11. The lower limit height OL is the lower limit height of the oil level of the engine oil in the oil pan 11b, which is a predetermined height in a general engine.

The oil return pipe 30 has a portion that is pulled out from the end portion on the side connected to the oil pan 11b and extends so as to penetrate the side surface of the oil tank 22 in a horizontal direction and plunge into the inside. Further, a portion of the oil return pipe 30 located inside the oil tank 22 is bent upward in an L shape and extends to this portion on the side opposite to the side where the oil return pipe 30 is connected to the oil pan 11b. The end of is located.

The end of the oil return pipe 30 located on the oil tank 22 side forms a second opening 32 leading to the internal space of the oil tank 22. The second opening 32 is arranged upward at a position away from the inner wall of the oil tank 22. Further, the height at which the second opening 32 is arranged inside the oil tank 22 substantially coincides with the upper limit height OF of the oil level defined for the engine 11. Therefore, the height of the first opening 31 described above is lower than the height of the second opening 32. The upper limit height OF is the oil level upper limit height of the engine oil in the oil pan 11b, which is a predetermined height in a general engine.

A margin is set between the height of the second opening 32 and the upper limit height OF of the oil level in consideration of, for example, a dimensional error, and as a result, the heights may not exactly match. Even in this case, it is sufficient that the height of the second opening 32 and the upper limit height OF of the oil level are substantially the same.

With the above configuration, when the engine 11 is operated, the oil level OC in the oil pan 11b gradually decreases as the engine oil gradually decreases. However, the oil level OC in the oil pan 11b can be restored by driving the oil pump 24 at an appropriate timing to replenish the oil pan 11b with the engine oil in the oil tank 22.

By driving the oil pump 24 to supply engine oil from the oil tank 22 to the oil pan 11b, the oil level OC in the oil pan 11b rises. When the oil level OC is equal to or higher than the height of the first opening 31, engine oil flows into the oil return pipe 30 from the first opening 31. After that, the oil level height of the engine oil in the oil return pipe 30 coincides with the oil level height OC of the oil pan 11b, and changes in conjunction with the change of the oil level height OC of the oil pan 11b. It is assumed that the supply of engine oil from the oil tank 22 to the oil pan 11b further raises the oil level OC in the oil pan 11b and exceeds the height of the second opening 32. Then, the engine oil in the oil return pipe 30 is discharged from the second opening 32 so as to overflow into the oil tank 22. Therefore, the oil level OC in the oil pan 11b does not become higher than the height of the second opening 32. Therefore, for example, the height of the second opening 32 is set to match the upper limit height OF of the oil level. Therefore, it is possible to prevent the oil level in the oil pan 11b from exceeding the upper limit height OF of the oil level.

As described above, the oil supply device 4 of the present embodiment intermittently drives the oil pump 24 even when the engine 11 is continuously operated for a long period of time, thereby causing the oil level OC in the oil pan 11b. Can be easily maintained at a height between the lower limit height OL and the upper limit height OF of the oil level. Further, by shortening the drive interval of the oil pump 24, the oil level OC can be stably maintained in the vicinity of the upper limit height OF of the oil level, so that a large amount of engine oil can be stored in the oil pan 11b. The engine 11 can be driven in a state where the oil is stored. As a result, deterioration of the engine oil can be alleviated.

Further, in the present embodiment, the path for returning the engine oil from the oil pan 11b to the oil tank 22 is composed of a tubular member (oil return pipe 30). Therefore, the configuration can be simplified and the labor and cost at the time of manufacturing can be reduced as compared with the case where the shape of the oil tank is special.

The pressure equalizing pipe 40 is configured as an elongated pipe, and as shown in FIG. 5, air flows between the inside of the engine 11 and the inside of the oil tank 22. Specifically, as shown in FIG. 4, the end portion of the pressure equalizing pipe 40 on one side in the longitudinal direction has a portion that rushes downward from the upper surface of the oil tank 22 in a small amount, and the lower end portion of this portion has a portion. A third opening 41, which is an opening communicating with the internal space of the oil tank 22, is formed. The third opening 41 is arranged downward at a position away from the inner wall of the oil tank 22. Further, the height at which the third opening 41 is arranged is a height near the upper end portion of the internal space of the oil tank 22, which is higher than the second opening 32 of the oil return pipe 30.

In the pressure equalizing pipe 40, the end portion on the side opposite to the side connected to the oil tank 22 is connected to the cylinder block 11a included in the engine 11. The height of the opening 42 formed by the pressure equalizing pipe 40 in the internal space of the engine 11 is higher than the upper limit height OF of the oil level of the engine 11.

With this configuration, when engine oil is supplied from the oil tank 22 to the oil pan 11b by the oil pump 24, the amount of air is returned from the internal space of the engine 11 to the oil tank 22 via the pressure equalizing pipe 40 to return the engine. A smooth supply of oil is achieved.

As shown in FIGS. 5 and 6A, the third opening 41 formed by the pressure equalizing pipe 40 in the internal space of the oil tank 22 is arranged directly above the second opening 32 of the oil return pipe 30. The third opening 41 is arranged so as to face the second opening 32 in the vertical vertical direction. The circular third opening 41 of the pressure equalizing pipe 40 is formed smaller than the circular second opening 32 of the oil return pipe 30. Then, as shown in FIG. 6B in a plan view, the entire contour of the third opening 41 is configured to be inside the contour of the second opening 32.

As a result, the engine oil that lubricates each part of the engine 11 is mixed into the pressure equalizing pipe 40 from the opening 42 while falling along the inner wall of the cylinder block 11a, passes through the pressure equalizing pipe 40, and falls from the third opening 41. Even so, the engine oil will fall inside the second opening 32 of the oil return pipe 30. Therefore, it is possible to prevent the engine oil on the engine 11 side from returning to the oil tank 22 and maintain a good oil level in the oil pan 11b.

As described above, the heat pump device 1 of the present embodiment is driven by the engine 11. The heat pump device 1 includes an oil tank 22, an oil pump 24, and an oil return pipe 30. The oil tank 22 stores engine oil to be supplied to the oil pan 11b included in the engine 11. The oil pump 24 supplies engine oil from the oil tank 22 to the oil pan 11b. The oil return pipe 30 returns the engine oil of the oil pan 11b to the oil tank 22. The height of the first opening 31 which is the opening formed by the oil return pipe 30 in the internal space of the oil pan 11b is higher than the height of the second opening 32 which is the opening formed by the oil return pipe 30 in the internal space of the oil tank 22. Is also low.

As a result, as a result of supplying the engine oil to the oil pan 11b, when the oil level height in the oil pan 11b rises and exceeds the height of the first opening 31 in the oil pan 11b, the engine oil is supplied to the first opening 31. Flows into the oil return pipe 30. When the oil level OC in the oil pan 11b further rises and exceeds the height of the second opening 32 in the oil tank 22, the amount of engine oil in the oil return pipe 30 corresponding to the excess is increased. 2 It overflows from the opening 32 and is automatically returned to the oil tank 22. Therefore, if the oil pump 24 is sufficiently driven, the oil level OC in the oil pan 11b can be surely raised to the height of the second opening 32 and maintained at the height of the second opening 32. Can be done. As a result, the oil level OC in the oil pan 11b can be easily controlled. Further, since the engine oil of the oil pan 11b is returned by the oil return pipe 30, the labor and cost at the time of manufacturing can be reduced. Further, by adopting the above simple configuration, the manufacturability of the heat pump device 1 (particularly, the portion where the engine oil of the oil pan 11b is returned to the oil tank 22) is improved, and the malfunction due to the manufacturing defect is suppressed. Can be stabilized.

Further, in the heat pump device 1 of the present embodiment, the height of the first opening 31 is lower than the lower limit height OL of the oil level of the engine oil in the oil pan 11b defined for the engine 11.

As a result, the engine oil can be returned to the oil tank 22 from a sufficiently low position of the oil pan 11b via the oil return pipe 30. As a result, the amount of engine oil that stays at the bottom of the oil pan 11b can be reduced, and the cleanliness of the engine oil can be improved.

Further, in the heat pump device 1 of the present embodiment, the second opening 32 of the oil return pipe 30 has a height substantially equal to the upper limit height OF of the oil level of the engine oil in the oil pan 11b defined for the engine 11. Have been placed.

As a result, it becomes easy to maintain the oil level of the engine oil in the oil pan 11b high, so that deterioration of the engine oil can be suppressed.

Further, in the heat pump device 1 of the present embodiment, the oil return pipe 30 has a portion that passes through the side wall of the oil tank 22 and a portion that bends upward inside the oil tank 22.

As a result, the oil return pipe 30 has a simple shape, so that the oil return pipe 30 can be easily formed.

Further, the heat pump device 1 of the present embodiment includes a pressure equalizing pipe 40 for circulating air between the internal space of the engine 11 and the internal space of the oil tank 22. The third opening 41, which is an opening formed by the pressure equalizing pipe 40 in the internal space of the oil tank 22, is arranged directly above the second opening 32. The contour of the third opening 41 is entirely included inside the contour of the second opening 32 when viewed in a plan view.

As a result, the engine oil is pumped from the oil pan 11b by the lubrication pump, lubricates each part of the engine 11 and returns to the oil pan 11b, and the engine oil is mixed into the pressure equalizing pipe 40 and returned to the oil tank 22. Even if it is done, the engine oil can be received by the oil return pipe 30. As a result, the engine oil can be supplied to the oil pan 11b via the oil return pipe 30, and the oil level in the oil pan 11b can be prevented from dropping.

Next, a first modification of the above embodiment will be described. FIG. 7 is a perspective view showing a heat pump device of the first modification.

In the heat pump device of the first modification shown in FIG. 7, a funnel-shaped receiving portion (passage expanding portion) 30x that expands as it goes upward is formed at the end of the oil return pipe 30 located inside the oil tank 22. ing. The receiving portion 30x is formed so that the internal passage formed in the oil return pipe 30 becomes wider as it approaches the second opening 32. The second opening 32 is arranged at the end of the receiving portion 30x. As a result, the opening area of the second opening 32 can be widened, so that the engine oil falling from the third opening 41 of the pressure equalizing pipe 40 can be reliably received. The receiving portion 30x may be formed of a mesh (for example, a metal mesh).

As described above, in the heat pump device of this modified example, the oil return pipe 30 is formed with a receiving portion 30x whose internal passage becomes wider as it approaches the second opening 32.

Thereby, for example, even when a thin pipe is used as the oil return pipe 30, the engine oil falling from the third opening 41 of the pressure equalizing pipe 40 can be reliably received.

Next, a second modification of the above embodiment will be described. FIG. 8 is a schematic view showing a heat pump device of the second modification.

In the heat pump device of the second modification shown in FIG. 8, the oil pan 11bx included in the engine 11 has a portion protruding in a horizontal direction with respect to the cylinder block 11a. The opening 42 formed by the pressure equalizing pipe 40 in the internal space of the engine 11 is arranged downward on the ceiling surface of the overhanging portion.

The second opening 32 through which the oil return pipe 30 communicates with the internal space of the oil tank 22 is arranged on the inner wall of the side wall of the oil tank 22 in a substantially horizontal direction. The height of the lower end of the second opening 32 coincides with the upper limit height OF of the oil level. In this modification, the oil return pipe 30 does not have a portion that enters the inside of the oil tank 22.

In this second modification, since the opening 42 of the pressure equalizing pipe 40 faces downward, it is unlikely that the engine oil that lubricates each part of the engine 11 is mixed into the pressure equalizing pipe 40 and returns to the oil tank 22. Therefore, the opening formed by the pressure equalizing pipe 40 inside the oil tank 22 is not located directly above the second opening 32, unlike the above-described embodiment and the like.

Although preferred embodiments and modifications of the present invention have been described above, the above configuration can be changed as follows, for example.

The height of the first opening 31 may be arranged higher than the lower limit height OL of the oil level of the engine oil. However, it is preferable that the first opening 31 is arranged at the bottom of the oil pan 11b because it is possible to prevent the engine oil from stagnation at the bottom of the oil pan 11b.

The shape of the oil tank 22 is not limited to the rectangular parallelepiped shape, and may be changed in various ways.

The layout of the oil return pipe 30 is arbitrary, and for example, the oil return pipe 30 may be configured to extend obliquely inside the oil tank 22.

When the positions of the third opening 41 and the second opening 32 do not correspond in the vertical direction, for example, a gutter-shaped guide portion that inclines so as to guide the engine oil falling from the third opening 41 to the second opening 32 is an oil tank. It may be provided inside 22.

The oil pump 24 and the oil filter 26 may be arranged at any position on the oil supply pipe 23. However, as described in the above embodiment, the oil filter 26 is preferably arranged upstream of the oil pump 24 in the oil supply pipe 23. This makes it possible to prevent the oil pump 24 from being clogged with foreign matter.

A sensor for detecting the height of the oil level may be provided in the oil pan 11b so as to drive the oil pump 24 when a drop in the oil level is detected.

1 Heat pump device 11 Engine
11b Oil pan 22 Oil tank 24 Oil pump 30 Oil return pipe 31 1st opening 32 2nd opening

Claims (5)

A heat pump device driven by an engine
An oil tank for storing engine oil supplied to the engine oil pan and
A pump that supplies engine oil from the oil tank to the oil pan,
An oil return pipe that returns the engine oil from the oil pan to the oil tank,
An air flow pipe that allows air to flow between the internal space of the engine and the internal space of the oil tank.
With
The height of the first opening, which is the opening formed by the oil return pipe in the internal space of the oil pan, is higher than the height of the second opening, which is the opening formed by the oil return pipe in the internal space of the oil tank. has become low,
The third opening, which is the opening formed by the air flow pipe in the internal space of the oil tank, is arranged directly above the second opening.
A heat pump device characterized in that the contour of the third opening is entirely contained inside the contour of the second opening when viewed in a plan view. The heat pump device according to claim 1.
A heat pump device characterized in that the height of the first opening is lower than the lower limit height of the oil level of the engine oil in the oil pan, which is defined for the engine. The heat pump device according to claim 1 or 2.
A heat pump device characterized in that the second opening of the oil return pipe is arranged at a height substantially coincide with an oil level upper limit height of engine oil in the oil pan, which is defined for the engine. The heat pump device according to any one of claims 1 to 3.
The heat pump device is characterized in that the oil return pipe has a portion that passes through the side wall of the oil tank and a portion that bends upward inside the oil tank. The heat pump device according to any one of claims 1 to 4.
A heat pump device characterized in that the oil return pipe is formed with a passage expanding portion in which an internal passage becomes wider as it approaches the second opening.

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