JP2010053596A - Construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy-saving construction machine capable of improving the cooling efficiency of an electric motor through a minor modification. <P>SOLUTION: A hybrid shovel includes a twin variable-displacement hydraulic pump 22; a dynamo-electric generator-cum-electric motor 21 for driving the twin variable-displacement hydraulic pump 22; an actuator part to be driven by a hydraulic operating fluid discharged from the twin variable-displacement hydraulic pump 22; and a cooling channel 30 into which drain oil from the twin variable-displacement hydraulic pump 22 flows. Since the drain oil of the twin variable-displacement hydraulic pump 22 flows into the cooling channel 30 to cool the dynamo-electric generator-cum-electric motor 21, allowing the dynamo-electric generator-cum-electric motor 21 to be cooled with cooling efficiency higher than air cooling method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a construction machine such as a hydraulic excavator, a crane, a bulldozer, or a pile driver.

In recent years, construction machinery has been required to take environmental measures such as reducing CO ₂ emissions. In response, hydraulic excavators are hybridized between an engine and an electric motor, just like a passenger car.

  Conventionally, as a hybrid excavator, there is one described in Japanese Patent Application Laid-Open No. 2002-174202 (Patent Document 1). This hybrid excavator includes a generator driven by an engine or an electric motor that uses a battery as a power source, a hydraulic pump that rotates using the electric motor as a drive source, and a hydraulic cylinder that is driven by the hydraulic pump.

  By the way, the conventional hybrid excavator has many uses in which the rotational speed of the electric motor is frequently changed in a short time unlike a passenger car. Such usage greatly reduces the efficiency of the electric motor, and increases the heat generation of the electric motor.

  Therefore, it is necessary to actively cool the motor by air cooling to prevent the motor from overheating.

  However, in the conventional hybrid excavator, even if the electric motor is remodeled to an air-cooled electric motor, there is no space for providing a wind passage for guiding the air that cools the electric motor.

  Therefore, the conventional hybrid excavator must be greatly modified in order to air-cool the electric motor.

  Moreover, even if the motor is air-cooled, the cooling efficiency of the motor by wind is low, so that the motor during high heat generation may not be sufficiently cooled.

  The cooling efficiency of the electric motor can be increased by cooling the electric motor with water, but the conventional hybrid excavator does not have a space for mounting cooling water piping, a cooling water pump, and a radiator for the water cooling.

  Therefore, the water cooling of the electric motor is accompanied by a large-scale modification as in the case of air cooling.

As described above, the conventional hybrid excavator has a problem that the cooling efficiency of the electric motor cannot be increased by a slight modification.
JP 2002-174202 A

  Accordingly, an object of the present invention is to provide a construction machine that can increase the cooling efficiency of the electric motor with a slight modification.

In order to solve the above problems, the construction machine of the present invention is
A hydraulic pump;
A first electric motor for driving the hydraulic pump;
An actuator driven by hydraulic oil discharged from the hydraulic pump;
The hydraulic oil from the hydraulic pump flows in and a cooling passage for cooling the first electric motor is provided.

  According to the construction machine having the above-described configuration, the hydraulic oil of the hydraulic pump flows into the cooling passage and cools the first motor, so that the first motor can be cooled with higher cooling efficiency than air cooling.

  Further, when the conventional hybrid excavator is modified to the above-described configuration, it is not necessary to add a cooling water pipe, a cooling water pump, and a radiator. For example, since the hydraulic circuit can be modified, the amount of modification is reduced.

  Therefore, by using the above configuration, the cooling efficiency of the electric motor of the conventional hybrid excavator can be increased with a slight modification.

The construction machine of one embodiment is
The hydraulic oil for the hydraulic pump is drain oil.

  According to the construction machine of the said embodiment, since the hydraulic oil of the said hydraulic pump is drain oil, drain oil can be used effectively.

The construction machine of one embodiment is
A second electric motor that directly drives the actuator;
A cooling passage through which hydraulic oil for cooling the second electric motor flows.

  According to the construction machine of the said embodiment, since the hydraulic fluid which flows through the said cooling channel cools a 2nd electric motor, a 2nd electric motor can be cooled with a cooling efficiency higher than air cooling.

In the construction machine of one embodiment,
The second electric motor has an electric motor main body and a wet brake attached to the electric motor main body,
A cooling passage through which hydraulic oil for cooling the wet brake flows is provided.

  According to the construction machine of the said embodiment, since the hydraulic fluid which flows through the said cooling channel cools a wet brake, the structure only for cooling a wet brake becomes unnecessary, and it can prevent that a cooling structure becomes complicated. .

In the construction machine of one embodiment,
The cooling passage through which the hydraulic oil for cooling the wet brake flows is connected to the cooling passage through which the hydraulic oil for cooling the electric motor body flows in a substantially straight line.

  According to the construction machine of the above-described embodiment, the cooling passage through which the hydraulic oil for cooling the wet brake flows is connected in a substantially straight line to the cooling passage through which the hydraulic oil for cooling the electric motor body flows. Since the electric motor main body and the wet brake are sequentially passed, both the electric motor main body and the wet brake can be cooled by flowing hydraulic oil through the cooling passage.

The construction machine of one embodiment is
The hydraulic fluid that cools the second electric motor is hydraulic fluid from a pilot pump.

  According to the construction machine of the above embodiment, since the hydraulic oil for cooling the second electric motor is hydraulic oil from the pilot pump, there is no need to install a pump for flowing hydraulic oil in the cooling passage in addition to the pilot pump. Well, the number of pumps does not increase.

  Therefore, the amount of modification for cooling the conventional hybrid excavator with hydraulic oil can be reduced.

  According to the construction machine of the present invention, since the hydraulic oil of the hydraulic pump flows into the cooling passage and cools the first motor, the first motor can be cooled with higher cooling efficiency than air cooling.

  Further, when the conventional hybrid excavator is modified in the above configuration, it is not necessary to add a cooling water pipe, a cooling water pump, and a radiator. For example, since the hydraulic circuit is modified, the amount of modification is reduced.

  Therefore, by using the above configuration, the cooling efficiency of the electric motor can be increased with a slight modification of the conventional hybrid excavator.

  Hereinafter, the construction machine of the present invention will be described in detail with reference to the illustrated embodiments.

[First Embodiment]
FIG. 1 is a schematic perspective view of a hybrid excavator 1 according to a first embodiment of the present invention.

  The hybrid excavator 1 includes a lower traveling body 2, an upper revolving body 3 that is turnably mounted on the lower traveling body 2, an excavation work machine 4 that is attached to the upper revolving body 3 and performs excavation work and the like. It has. The lower traveling body 2 and the upper swing body 3 constitute a vehicle body of the hybrid excavator 1. In the following description, “front side”, “rear side”, “left side”, and “right side” mean the front side, the rear side, the left side, and the right side with respect to the lower traveling body 2 unless otherwise specified.

  The lower traveling body 2 is provided with a traveling crawler 5 and a blade 6 for performing leveling work and the like. The lower traveling body 2 is provided with a traveling hydraulic motor 15 for driving the crawler 5 and a blade cylinder 16 for driving the blade 6.

  The upper swing body 3 is provided with an operator cabin 7. A tank 8 for storing hydraulic oil is installed on the rear side of the operator cabin 7. A machine cab 9 is installed on the right side of the operator cabin 7.

  The excavation work machine 4 includes a boom 10 whose base end is rotatably connected to the upper swing body 3, an arm 11 rotatably connected to the tip of the boom 10, and a tip of the arm 11. And a bucket 12 rotatably connected to the section. The excavator 4 is provided with a boom cylinder 17 for driving the boom 10, an arm cylinder 18 for driving the arm 11, and a bucket cylinder 19 for driving the bucket 12. .

  One end of the boom cylinder 17 is rotatably supported by the upper swing body 3, and the tip of the rod 17 a, which is the other end, is rotatably connected to the base end portion of the boom 10. Is rotated (raised) around the base end.

  One end of the arm cylinder 18 is pivotally supported on the upper surface of the boom 10, and the other end of the rod 18 a is pivotally connected to the arm 11. Rotate around the connecting shaft.

  One end of the bucket cylinder 19 is rotatably supported on the front surface of the arm 11, and the tip of the rod 19 a, which is the other end, is rotatably connected to the bucket 12. Rotate around the connecting shaft.

  FIG. 2 is a schematic diagram showing a configuration of a main part of the hybrid excavator 1.

  The hybrid excavator 1 includes an engine 20, a generator / motor 21 driven by the engine 20, a dual variable displacement hydraulic pump 22 driven by the engine 20, and a discharge port of the dual variable displacement hydraulic pump 22. A multi-valve 23 connected to the multi-valve 23 through the main line 26 and an actuator unit 24 connected to the multi-valve 23. The generator / motor 21 is an example of a first motor, the dual variable displacement hydraulic pump 22 is an example of a hydraulic pump, and the actuator unit 24 is an example of an actuator.

  The generator / motor 21 is installed between the engine 20 and the dual variable displacement hydraulic pump 22 and is directly connected to a shaft connected to the engine 20 and the dual variable displacement hydraulic pump 22. The generator / motor 21 is used as a generator when the load of the engine 20 is low, and stores the generated electricity in the power storage device 29. On the other hand, when the load of the engine 20 is high, the generator / motor 21 assists the engine 20 using electricity stored in the power storage device 29.

  The dual variable displacement hydraulic pump 22 includes a first pump part P1 and a second pump part P2. The dual variable displacement hydraulic pump 22 sucks the hydraulic oil in the tank 8 and supplies it to the multi-valve 23 via the main line 26.

  The multi-valve 23 allows the hydraulic oil from the double variable displacement hydraulic pump 22 to flow to the actuator unit 24 or not. The multi-valve 23 includes a travel operation valve, a blade operation valve, a boom cylinder operation valve, an arm operation valve, and a bucket operation valve (not shown).

  The actuator unit 24 includes a traveling hydraulic motor 15, a blade cylinder 16, a boom cylinder 17, an arm cylinder 18, and a bucket cylinder 19 (see FIG. 1). The travel hydraulic motor 15 has a travel operation valve open, the blade cylinder 16 has a blade operation valve open, the boom cylinder 17 has a boom cylinder operation valve open, and the arm cylinder 18 has an arm operation. The hydraulic oil is supplied to the bucket cylinder 19 when the bucket valve is opened and when the bucket operation valve is opened.

  The controller 27 also controls the rotational speed of the drive shaft of the turning electric motor 25. More specifically, the controller 27 sends a signal corresponding to the operation amount of the operation lever 28 to the turning electric motor 25.

  As shown in FIG. 1, the turning electric motor 25 is mounted on the upper turning body 3 and uses electricity stored in the power storage device 29. The upper-part turning body 3 is turned by the driving force of the turning electric motor 25.

  FIG. 3 is a schematic diagram for explaining a part of FIG. 2 in more detail. In FIG. 3, the dual variable displacement hydraulic pump 22 is shown in a simplified manner.

  A cooling passage 30 is provided in a housing (not shown) of the generator / motor 21. The cooling passage 30 guides the drain oil of the dual variable displacement hydraulic pump 22 to a portion upstream of the oil cooler 32 in the discharge line 31. The hydraulic oil flows through the cooling passage 30, absorbs heat from the generator / motor 21, enters the discharge line 31, releases the absorbed heat by the oil cooler 32, and returns to the tank 8.

  According to the hybrid excavator 1 having the above-described configuration, the hydraulic oil discharged from the dual variable displacement hydraulic pump 22 flows into the cooling passage 30 and cools the generator / motor 21, so that the cooling efficiency is higher than that of air cooling. The generator / motor 21 can be cooled.

  Further, for example, when the conventional hybrid excavator described in Japanese Patent Application Laid-Open No. 2002-174202 is modified to the above-described configuration, it is not necessary to add a cooling water pipe, a cooling water pump, and a radiator. Since remodeling is sufficient, the amount of modification is small.

  Therefore, by using the above configuration, the cooling efficiency of the electric motor of the conventional hybrid excavator can be increased with a slight modification.

  Further, when the conventional hybrid excavator is modified to the above configuration, the number of pipes can be reduced as compared with the case where the generator / motor 21 is cooled by water cooling.

  Further, since the drain oil of the dual variable displacement hydraulic pump 22 flows into the cooling passage 30, it is not necessary to install a pump for flowing the hydraulic oil through the cooling passage 30 in addition to the dual variable displacement hydraulic pump 22. Well, the number of pumps does not increase.

  Therefore, the amount of modification for cooling the conventional hybrid excavator with hydraulic oil can be reduced.

  In the first embodiment, the generator / motor 21 is cooled by the drain oil of the double variable displacement hydraulic pump 22. However, the generator / motor 21 may be cooled by the hydraulic oil of the main line 26. Good. In other words, any oil that has exited the dual variable displacement hydraulic pump 22 may be used to cool the generator / motor 21.

[Second Embodiment]
FIG. 4 is a schematic diagram showing the configuration of the main part of the hybrid excavator according to the second embodiment of the present invention. In FIG. 4, the same components as those of the first embodiment shown in FIGS. 2 and 3 are denoted by the same reference numerals as those of the components in FIGS.

  The hybrid excavator includes a pilot pump 122, a turning electric motor 125 for turning the upper turning body, and a cooling line 130 for cooling the turning electric motor 125. The turning electric motor 125 is an example of a second electric motor, and the cooling line 130 is an example of a cooling passage.

  The pilot pump 122 is driven by an engine (not shown) as in the first embodiment, and a generator / motor (not shown) is installed between the engine and the pilot pump 122. One end of a pilot line 126 is connected to the discharge port of the pilot pump 122.

  The turning electric motor 125 includes an electric motor main body 136, a wet brake 137 attached to the electric motor main body 136, a reduction gear 138 for reducing the driving force generated by the electric motor main body 136 and transmitting it to the driving shaft 139, and a driving shaft. 139 and a pinion gear 140 attached to the tip portion of 139. The pinion gear 140 meshes with an internal gear single row ring gear (not shown) fixed to the lower traveling body.

  The cooling line 130 is provided so as to be wound around the electric motor main body 136 and through the wet brake 137 and the reduction gear 138. The upstream end of the cooling line 130 is connected to a portion on the upstream side of the restriction 135 in the relief line 133. On the other hand, the downstream end of the cooling line 130 is connected to the upstream side of the oil cooler 32 in the discharge line 31.

  The relief line 133 is provided with a relief valve 134 and a throttle 135 so that hydraulic oil can flow from the pilot line 126. Part of the hydraulic oil discharged from the relief valve 134 enters the cooling line 130, passes through the oil cooler 32, and then returns to the tank 8. Further, the remaining hydraulic oil discharged from the relief valve 134 returns to the tank 8 via the throttle 135.

  According to the hybrid excavator having the above-described configuration, when the relief valve 134 is opened, the hydraulic oil in the pilot line 126 flows into the cooling line 130 through the relief valve 134. Thus, after the hydraulic oil cools the electric motor main body 136, the wet brake 137 and the reduction gear 138 are cooled, so that the electric motor main body 136, the wet brake 137 and the reduction gear 138 are cooled with higher cooling efficiency than air cooling. Can do.

  Further, for example, when the conventional hybrid excavator described in Japanese Patent Application Laid-Open No. 2002-174202 is modified to the above configuration, it is not necessary to add a cooling water pipe, a cooling water pump, and a radiator. Because it is completed, the amount of modification is small.

  Therefore, by using the above configuration, the cooling efficiency of the electric motor of the conventional hybrid excavator can be increased with a slight modification.

  Further, when the conventional hybrid excavator is modified to the above configuration, the number of pipes can be reduced as compared with the case where the turning electric motor 125 is cooled by water cooling.

  Further, since the hydraulic oil discharged from the relief valve 134 flows into the cooling line 130, it is not necessary to install a pump for flowing the hydraulic oil to the cooling line 130 in addition to the dual variable displacement hydraulic pump 22. The number of pumps does not increase.

  Therefore, the amount of modification for cooling the conventional hybrid excavator with hydraulic oil can be reduced.

  In the second embodiment, a cooling passage similar to that in the first embodiment may be provided in the housing of the generator / motor. That is, the cooling passage of the first embodiment may be used in the second embodiment.

  In the second embodiment, instead of the cooling line 130, the cooling line 230 shown in FIG. 5 having a portion extending in a substantially straight line along the axial direction of the drive shaft 139 may be used. The hydraulic oil that has entered the cooling line 230 sequentially flows through the electric motor main body 136, the wet brake 137, and the reduction gear 138 to be cooled. When the cooling line 230 is used, the hydraulic oil pressure loss can be reduced as compared with the cooling line 130.

  In the first and second embodiments, an example in which the present invention is applied to a parallel hybrid excavator has been described. However, the present invention may be applied to a series hybrid excavator. That is, the present invention is not limited to a system such as a series system or a parallel system, and can be used for various types of hybrid construction machines.

  Further, the present invention can be applied to, for example, a hybrid crane, a hybrid bulldozer, a hybrid pile driver other than the hybrid excavator. Moreover, what combined the said 1st Embodiment and the said 2nd Embodiment suitably is good also as one Embodiment of this invention.

FIG. 1 is a schematic perspective view of a hybrid excavator according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing a configuration of a main part of the hybrid excavator according to the first embodiment. FIG. 3 is a schematic diagram for explaining a part of FIG. 2 in more detail. FIG. 4 is a schematic diagram showing the configuration of the main part of the hybrid excavator according to the second embodiment of the present invention. FIG. 5 is a schematic diagram of a main part of a modification of the hybrid excavator of the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid excavator 8 Tank 21 Generator / motor 22 Dual variable displacement hydraulic pump 24 Actuator section 26 Main line 30 Cooling passage 122 Pilot pump 125 Turning motors 130 and 230 Cooling line 136 Motor main body 133 Relief line 134 Relief valve 135 Restriction 137 Wet brake 138 Reduction gear

Claims (6)

A hydraulic pump (22);
A first electric motor (21) for driving the hydraulic pump (22);
An actuator (24) driven by hydraulic oil discharged from the hydraulic pump (22);
A construction machine comprising: a hydraulic passage from the hydraulic pump (22) and a cooling passage (30) for cooling the first electric motor (21). The construction machine according to claim 1,
A construction machine, wherein the hydraulic oil of the hydraulic pump (22) is drain oil. The construction machine according to claim 1 or 2,
A second electric motor (125) that directly drives the actuator (24);
A construction machine comprising cooling passages (130, 230) through which hydraulic oil for cooling the second electric motor (125) flows. The construction machine according to claim 3,
The second electric motor (21, 125) includes an electric motor main body (136) and a wet brake (137) attached to the electric motor main body (136).
A construction machine comprising cooling passages (130, 230) through which hydraulic oil for cooling the wet brake (137) flows. The construction machine according to claim 4,
The cooling passage (230) through which the hydraulic oil for cooling the wet brake (137) flows is connected to the cooling passage (230) through which the hydraulic oil for cooling the electric motor body (136) flows in a substantially straight line. And construction machinery. In the construction machine according to any one of claims 3 to 5,
The construction oil for cooling the second electric motor (125) is hydraulic oil from a pilot pump (122).

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