Hydraulic Electric Construction Machinery

Abstract

To improve a temperature rising rate of an electrical heater.SOLUTION: A hydraulic shovel 1 comprises: a hydraulic pump 12 discharging pressure oil for driving a hydraulic actuator; an oil tank 14 supplying hydraulic oil to the hydraulic pump 12; and an electrical motor 11 driving the hydraulic pump 12. The hydraulic shovel 1 further comprises an electrical heater 20 for warming a driver seat 8. The electrical heater 20 is disposed to be adjacent to the oil tank 14.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a hydraulic electric construction machine, such as an electric hydraulic excavator, that drives a hydraulic pump using an electric motor as a power source. [Background technology]

[0002] Patent Document 1 discloses an electric construction machine that is equipped with an air conditioner compressor in a space-saving manner by improving the layout of the cooler. Patent Document 2 discloses a configuration for a hydraulic construction machine equipped with an engine, in which cooling water heated by the engine is circulated through piping inserted inside the driver's seat to raise the temperature of the driver's seat itself. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-242320 A [Patent Document 2] Japanese Utility Model Application Publication No. 7-42812 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, in cold regions, a heating device is provided in the cab to improve the working environment for the operator. As disclosed in Patent Document 2, in a hydraulic construction machine equipped with an engine, the cab can be heated using engine coolant that becomes hot while the engine is running. In contrast, in a hydraulic electric construction machine that does not have an engine, there is no electrical equipment that spontaneously generates a large amount of heat like an engine, so a separate electric heater must be provided. However, there is an issue that it takes a long time for the electric heater to heat up because the output is smaller than that of an engine.

[0005] An object of the present invention is to provide a hydraulic electric construction machine capable of improving the temperature rise speed of an electric heater. [Means for solving the problem]

[0006] The present invention relates to a hydraulic electric construction machine including a vehicle body having a driver's seat, a hydraulic actuator provided on the vehicle body, a hydraulic pump that discharges pressure oil for driving the hydraulic actuator, an oil tank that supplies hydraulic oil to the hydraulic pump, and an electric motor that drives the hydraulic pump. The hydraulic electric construction machine further includes an electric heater for heating the driver's seat, the electric heater comprising: With the main surface facing the oil tank, Located adjacent to the oil tank The temperature is increased by the heat transferred from the oil tank. It is characterized by the following. Effect of the Invention

[0007] According to the present invention, the temperature rise speed of the electric heater can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a right side view showing an electric hydraulic excavator according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing the upper rotating body with a part of the exterior cover removed. [Diagram 3] 3 is a perspective view of an upper rotating body as viewed from the direction of arrows III-III in FIG. 2. [Figure 4] This is an oblique view of the oil tank, oil cooler, electric fan, etc. as seen from the right side of the upper rotating body. [Diagram 5] FIG. 2 is a perspective view showing an oil tank, an oil cooler, an electric fan, a control device, etc. [Figure 6] FIG. 2 is a perspective view showing an electric heater, an oil tank, etc. [Figure 7] This is a front view of the electric heater, oil tank, etc. as seen from the front side of the upper rotating body. [Figure 8] 1 is a block diagram showing an electric heater, an air conditioning unit, an oil tank, an electric fan, a control device, etc. [Figure 9]13 is a flow chart showing an electric heater control procedure. [Figure 10] FIG. 11 is a perspective view showing an electric heater, an oil tank, etc. according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described in detail with reference to the accompanying drawings, taking as an example a case where the embodiment is applied to an electric hydraulic excavator, which is a representative hydraulic electric construction machine.

[0010] In the following description, the front-rear direction of the electric hydraulic excavator 1 refers to the working implement 5 side, and the rear side refers to the counterweight 9 side, which is opposite the working implement 5. The left-right direction of the electric hydraulic excavator 1 refers to a direction perpendicular to the front-rear direction.

[0011] An electric hydraulic excavator 1 (hereinafter referred to as hydraulic excavator 1) as a hydraulic electric construction machine is used, for example, at work sites such as civil engineering, demolition, and underground construction. The hydraulic excavator 1 of the embodiment is configured as a small hydraulic excavator (electric mini excavator, electric small hydraulic excavator) (for example, machine weight is about 1 to 6 tons) suitable for work in a narrow work site such as underground construction. That is, the hydraulic excavator 1 of the embodiment corresponds to a very small rear swing type hydraulic excavator or a small rear swing type hydraulic excavator. Moreover, the hydraulic excavator 1 of the embodiment is configured as a cab-equipped hydraulic excavator 1.

[0012] The hydraulic excavator 1 comprises a self-propelled crawler-type lower traveling body 2, an upper rotating body 4 rotatably mounted on the lower traveling body 2, and a working device 5 provided on the upper rotating body 4. The lower traveling body 2 and the upper rotating body 4 constitute a vehicle body of the hydraulic excavator 1. The vehicle body is capable of traveling and rotating. The vehicle body has a driver's seat 8. A swing-type working device 5 is attached to the front side of the upper rotating body 4 so that it can swing. The hydraulic excavator 1 performs work such as excavating earth and sand using the working device 5. The working device 5 is not limited to a swing type that can swing left and right, and may be one that cannot swing left and right.

[0013] The lower traveling body 2 is configured to include, for example, crawler belts 2A formed by attaching a plurality of shoes to endless track links, and left and right traveling hydraulic motors (not shown) that rotate the crawler belts 2A to cause the hydraulic excavator 1 to travel (self-propel). A turning device including a turning bearing and a turning hydraulic motor is provided between the lower traveling body 2 and the upper rotating body 4. A blade 3 that swings up and down by the extension and contraction of a blade cylinder (not shown) is attached to the front side of the lower traveling body 2.

[0014] The working device 5, also called the front device, has a swing post 5A that is provided on the front side of the revolving frame 6 so as to be swingable in the left-right direction. A boom 5B is rotatably attached to the swing post 5A. An arm 5C is rotatably attached to the tip of the boom 5B. A bucket 5D as a working tool is rotatably attached to the tip of the arm 5C. The working device 5 also includes a swing cylinder 5E that swings the swing post 5A, a boom cylinder 5F that rotates the boom 5B, an arm cylinder 5G that rotates the arm 5C, and a bucket cylinder 5H that rotates the bucket 5D as a working tool cylinder. The swing cylinder 5E, the boom cylinder 5F, the arm cylinder 5G, and the bucket cylinder 5H constitute a hydraulic actuator provided on the vehicle body.

[0015] The upper rotating body 4 rotates on the lower traveling body 2 by being driven by a hydraulic motor for rotation of the rotating device. The upper rotating body 4 is equipped with a rotating frame 6 which serves as a support structure (base frame). A cab 7, a counterweight 9, an exterior cover 10, an electric motor 11, a hydraulic pump 12, a battery device 13, an oil tank 14, a control valve device (not shown), etc. are mounted on the rotating frame 6. In this case, a working device 5 is attached to the front side of the rotating frame 6, and a counterweight 9 is attached to the rear side of the rotating frame 6.

[0016] The cab 7 is disposed on the left side of the rotating frame 6. The cab 7 is formed in a box shape. The inside of the cab 7 serves as a cab for the operator. Inside the cab 7, there are provided a driver's seat 8 where the operator sits, a travel lever / pedal and a work lever for operating the hydraulic excavator 1, and a monitor on which various information is displayed (none of which are shown). By operating the travel lever / pedal and the work lever, the operator can perform travel using the lower traveling body 2, rotation of the upper rotating body 4, excavation using the work device 5, and the like.

[0017] The counterweight 9 is provided at the rear end of the revolving frame 6, located rearward of the cab 7, in order to balance the weight with the working device 5. The counterweight 9 is formed as an arc-shaped heavy object that extends in the left-right direction with the center in the left-right direction protruding rearward. As a result, the rear surface of the counterweight 9 is formed as an arc surface that fits within an imaginary circle with a certain turning radius when the upper rotating body 4 turns.

[0018] The exterior cover 10 is located in front of the counterweight 9 and is provided on the revolving frame 6. As shown in Fig. 1, the exterior cover 10 covers the electric motor 11, the hydraulic pump 12, the battery device 13, the oil tank 14, etc. together with the counterweight 9.

[0019] The electric motor 11 is a power source for the hydraulic excavator 1. The electric motor 11 is mechanically connected to the hydraulic pump 12, that is, in a state in which power (rotation) can be transmitted. The electric motor 11 drives the hydraulic pump 12. The electric motor 11 is driven by power supply from a battery device 13 or power supply from an external power source (not shown).

[0020] For example, when the battery device 13 is sufficiently charged, the electric motor 11 is driven by power from the battery device 13. Also, when the electric motor 11 is connected to an external power source via a power supply cable (not shown), the electric motor 11 is driven by power from the external power source. The battery device 13 can be connected to the external power source via the power supply cable. This allows the battery device 13 to be charged by the external power source.

[0021] The hydraulic pump 12 supplies pressure oil to various hydraulic actuators (hydraulic cylinders, hydraulic motors) such as the boom cylinder 5F via a control valve device. The control valve device is a control valve group consisting of multiple directional control valves. The control valve device distributes the pressure oil discharged from the hydraulic pump 12 to multiple hydraulic actuators (hydraulic cylinders, hydraulic motors) such as the boom cylinder 5F in response to the operation of the travel lever / pedal and the work lever. This enables the hydraulic excavator 1 to travel, swing, excavate, etc.

[0022] The oil tank 14 supplies hydraulic oil to the hydraulic pump 12. The oil tank 14 is connected to the hydraulic pump 12 through hydraulic piping (not shown). The oil tank 14 is disposed on the right side of the revolving frame 6. The oil tank 14 stores hydraulic oil for driving each hydraulic actuator provided on the lower traveling body 2, the working device 5, etc. Here, the oil tank 14 is formed as a rectangular parallelepiped pressure-resistant container that is long in the vertical direction and made of metal plate material so that the pressure of the hydraulic oil acts on it.

[0023] As shown in Figs. 2 to 7, the oil tank 14 is composed of a front plate 14A, a rear plate 14B, a left plate 14C, a right plate 14D, an upper plate 14E, and a lower plate 14F. The right plate 14D is located outside the upper rotating body 4 in the left-right direction. As shown in Fig. 5, a temperature sensor 15 for detecting the temperature of the hydraulic oil is attached to the rear plate 14B of the oil tank 14. An oil cooler 16 and an electric fan 26 for cooling the oil cooler are attached to the right plate 14D of the oil tank 14. At this time, the oil cooler 16 is sandwiched between the oil tank 14 and the electric fan 26. The oil cooler 16 has a heat dissipation section through which return oil from each hydraulic actuator flows. The oil cooler 16 cools the hydraulic oil returning to the oil tank 14 by dissipating the heat of the return oil into the cooling air.

[0024] The left face plate 14C of the oil tank 14 is formed in a substantially flat shape. As shown in Figures 6 and 7, an electric heater 20 is attached to the oil tank 14 via a bracket 17. The oil tank 14 is not limited to a rectangular parallelepiped shape, and may be in other shapes, such as a triangular prism, a cylindrical shape, or a hemispherical shape.

[0025] The bracket 17 is attached to the oil tank 14. The bracket 17 is formed of a flat plate bent into an L-shape. As shown in FIG. 7, a fixing portion 18A is provided on the top plate 14E of the oil tank 14. A fixing portion 18B is provided on the left plate 14C of the oil tank 14. The fixing portions 18A and 18B are fixed to the oil tank 14 by welding or the like. Bolt holes are formed in the fixing portions 18A and 18B. One end of the bracket 17 is fixed to the fixing portion 18A by using a bolt 19. The other end of the bracket 17 is fixed to the fixing portion 18B by using a bolt 19. Thus, the bracket 17 extends from the top plate 14E to the left plate 14C.

[0026] The electric heater 20 is used to heat the driver's seat 8. The electric heater 20 is formed, for example, in a rectangular box shape. As shown in FIG. 6, the electric heater 20 has two main surfaces 20A and 20B facing each other. An upper surface 20C, a lower surface 20D, and side surfaces 20E and 20F are provided between the main surface 20A and the main surface 20B. The areas of the main surfaces 20A and 20B are larger than the areas of the upper surface 20C, the lower surface 20D, and the side surfaces 20E and 20F. The electric heater 20 is attached to the oil tank 14 using a bracket 17 with the main surface 20A facing the left panel 14C of the oil tank 14. This allows heat from the oil tank 14 to be transmitted to the electric heater 20 by, for example, thermal radiation. The electric heater 20 is fastened to the bracket 17 using a bolt 21 with the side surfaces 20E and 20F inclined from the up-down direction. At this time, the upper surface 20C is located above the electric heater 20 and is inclined toward the front of the vehicle body.

[0027] The electric heater 20 is configured, for example, by a PTC (Positive Temperature Coefficient) heater. The electric heater 20 heats a refrigerant such as water. The heating element of the electric heater 20 is configured, for example, by a PTC semiconductor. The temperature of the heating element of the electric heater 20 has a characteristic of remaining almost constant even when load fluctuations and voltage fluctuations occur.

[0028] The electric heater 20 has pipe openings 20G, 20H through which water (refrigerant) can flow in and out. The pipe openings 20G, 20H are provided on an upper surface 20C of the electric heater 20. The pipe openings 20G, 20H protrude from the upper surface 20C obliquely toward the front and upper direction of the vehicle body. Hot water pipes 22 are connected to the pipe openings 20G, 20H, respectively (see FIG. 3). As shown in FIG. 8, the electric heater 20 is connected to an air conditioning unit 23 called HVAC (Heating, Ventilation, and Air Conditioning) through the hot water pipe 22. Specifically, the electric heater 20 is connected to a heater core 24 of the air conditioning unit 23 through the hot water pipe 22. A pump 25 is attached midway through the hot water pipe 22. The pump 25 circulates hot water between the electric heater 20 and the air conditioning unit 23.

[0029] The air conditioning unit 23 is disposed, for example, under the driver's seat 8. When using heating, the operator turns on a heating switch (not shown). This drives the electric heater 20 and the pump 25. At this time, the pump 25 circulates water between the electric heater 20 and a heater core 24 of the air conditioning unit 23. The electric heater 20 heats the water passing through the inside. The water (hot water) heated by the electric heater 20 is supplied to the heater core 24. The air conditioning unit 23 supplies air inside or outside the cab 7 to the heater core 24. The heater core 24 warms the air using the hot water supplied from the electric heater 20. The air conditioning unit 23 supplies the hot air generated by the heater core 24 to the inside of the cab 7, for example, to the feet of the operator. When the heating switch is turned off, the electric heater 20 and the pump 25 are stopped.

[0030] The electric fan 26 is attached to the oil cooler 16. The electric fan 26 constitutes an oil cooler cooling fan. The electric fan 26 is driven by power supplied from the battery device 13 or an external power source, and supplies cooling air to the oil cooler 16. The driving of the electric fan 26 is controlled by the control device 27.

[0031] The control device 27 is disposed near the rear panel 14B and is covered by the exterior cover 10. The input side of the control device 27 is connected to, for example, a heating switch, a temperature sensor 15, etc. The output side of the control device 27 is connected to the electric fan 26.

[0032] Furthermore, the control device 27 controls the electric fan 26 for cooling the oil cooler based on the operating state of the electric heater 20 and the temperature detected by the temperature sensor 15. For this reason, the control device 27 is configured to include a microcomputer, and has memories such as flash memory, ROM, RAM, EEPROM, etc., and a calculation circuit (CPU). A control program for controlling the electric fan 26 is stored in the memory. Note that the control device 27 is not limited to controlling the electric fan 26, and may also control the electric motor 11, the electric heater 20, etc.

[0033] The hydraulic excavator 1 according to this embodiment has the configuration as described above. Next, the operation of the hydraulic excavator 1 when using the heating function will be described.

[0034] When starting operation of the hydraulic excavator 1, a warm-up operation is performed in order to reduce the viscosity of the hydraulic oil and protect the hydraulic equipment. At that time, high-temperature hydraulic oil circulates in the oil tank 14 mounted on the upper rotating body 4. As a result, the oil tank 14 itself becomes hot, and heat from the oil tank 14 is transferred to the electric heater 20 disposed adjacent to the surface of the oil tank 14. This causes the electric heater 20 to heat up, and therefore, when heating is used, the time it takes for the electric heater 20 to heat up the hot water can be shortened. In addition, the energy required to heat up the electric heater 20 can be suppressed, and therefore, the amount of energy consumed when heating is used can be reduced.

[0035] When the heating is used, the control device 27 receives a hydraulic oil temperature information signal from the temperature sensor 15. In response to this, the control device 27 controls the rotation speed of the electric fan 26 for cooling the oil cooler based on the electric fan control process shown in Fig. 9. The electric fan control process shown in Fig. 9 is repeatedly executed at predetermined time intervals.

[0036] First, in step 1, the control device 27 determines whether the electric heater 20 is driven. Whether the electric heater 20 is driven is determined based on whether the heating is in use. At this time, whether the heating is in use is determined based on, for example, a signal from a heating switch. When the electric heater 20 is stopped, the determination in step 1 is "NO" and the process proceeds to step 2. Note that in step 1, it may be determined whether the electric heater 20 is driven based on, for example, a drive signal for the electric heater 20 or a current supplied to the electric heater 20, without being limited to the signal from the heating switch.

[0037] In step 2, since the electric heater 20 is stopped, the control device 27 controls the electric fan 26 when the electric heater is not in use. Specifically, the control device 27 drives the electric fan 26 in accordance with the operating conditions of the hydraulic actuator and the temperature of the hydraulic oil. When the processing of step 2 ends, the process returns.

[0038] On the other hand, if the electric heater 20 is operating, the result in step 1 is "YES" and the process proceeds to step 3. In step 3, the control device 27 determines whether the actual temperature ΔT of the hydraulic oil has exceeded the set temperature. The set temperature is the temperature at which the hydraulic oil temperature does not rise excessively, and is preset to a value of, for example, about 80°C.

[0039] If the temperature ΔT of the hydraulic oil is higher than the set temperature, the result in step 3 is "YES", and the process proceeds to step 4. In step 4, the control device 27 drives the electric fan 26 for cooling the oil cooler. When the process in step 4 ends, the process returns.

[0040] On the other hand, if the temperature ΔT of the hydraulic oil is lower than the set temperature, the result in step 3 is "NO" and the process proceeds to step 5. In step 5, the electric fan 26 for cooling the oil cooler is stopped. In this way, for example, when starting the vehicle in low temperature, the electric fan 26 is not driven. This makes it possible to suppress cooling of the oil tank 14 and increase the heating speed of the electric heater 20. When the process in step 5 is completed, the process returns.

[0041] The control device 27 switches between driving and stopping the electric fan 26 in response to the hydraulic oil temperature ΔT while the electric heater 20 is in use. Therefore, for example, when the stopped machine is driven and parked idling, the electric fan 26 can be stopped in response to the hydraulic oil temperature ΔT. This makes it possible to prevent the hydraulic oil temperature ΔT from becoming too low.

[0042] The control device 27 controls whether to drive or stop the electric fan 26 in accordance with the hydraulic oil temperature ΔT. However, the present invention is not limited to this, and the control device 27 may control the rotation speed of the electric fan 26 in accordance with the hydraulic oil temperature ΔT. In this case, when the hydraulic oil temperature ΔT is low, the control device 27 rotates the electric fan 26 at a low speed. When the hydraulic oil temperature ΔT is high, the control device 27 rotates the electric fan 26 at a high speed.

[0043] Also, even when the heater is in use, the electric fan 26 may be driven in the same way as when the heater is not in use. In this case, the electric fan 26 may be driven according to the operating conditions of the hydraulic actuator and the temperature of the hydraulic oil. Furthermore, although the temperature rise time of the electric heater 20 is slowed down, the electric fan 26 may be driven all the time when the hydraulic excavator 1 is in operation or during warm-up, regardless of whether the heater is in use or not.

[0044] Thus, according to the first embodiment, the hydraulic excavator 1 includes a vehicle body having a driver's seat 8, a hydraulic actuator provided on the vehicle body, a hydraulic pump 12 that discharges pressure oil for driving the hydraulic actuator, an oil tank 14 that supplies hydraulic oil to the hydraulic pump 12, and an electric motor 11 that drives the hydraulic pump 12. The hydraulic excavator 1 also includes an electric heater 20, which is disposed adjacent to the oil tank 14. At this time, high-temperature hydraulic oil circulates in the oil tank 14 due to the driving of the hydraulic actuator and warm-up operation. Therefore, the oil tank 14 itself becomes hot, and heat from the oil tank 14 is transferred to the electric heater 20 disposed adjacent to the surface of the oil tank 14. As a result, the electric heater 20 is heated, and therefore, during heating, the time required for the electric heater 20 to heat up the hot water can be shortened. In addition, the energy required for heating the electric heater 20 can be suppressed, so that the amount of energy consumed during heating can be reduced.

[0045] In addition, the oil tank 14 has the largest heat dissipation surface area among all the hydraulic equipment piping. Therefore, by installing the electric heater 20 in the oil tank 14, the heat transfer efficiency when the heat from the hydraulic oil is supplied to the electric heater 20 is maximized.

[0046] In the first embodiment, a bracket 17 is provided on the oil tank 14, and the electric heater 20 is attached to the bracket 17. At this time, the electric heater 20 is assembled at a fixed position relative to the oil tank 14. Therefore, heat can be supplied from the oil tank 14 to the electric heater 20 according to the positional relationship between the electric heater 20 and the oil tank 14. In addition, the electric heater 20 can be attached to the oil tank 14 without directly threading the oil tank 14. Therefore, there is no need to worry about oil leaking from the oil tank 14, and the electric heater 20 can be easily attached and detached.

[0047] In the first embodiment, the hydraulic excavator 1 is provided with a temperature sensor 15 provided in the oil tank 14 for detecting the temperature of the hydraulic oil, and a control device 27 for controlling the rotation speed of an electric fan 26 (oil cooler cooling fan) based on a signal from the temperature sensor 15. When the electric heater 20 is being driven and the temperature detected by the temperature sensor 15 (temperature ΔT) is equal to or lower than a set temperature, the control device 27 stops the rotation of the electric fan 26 for cooling the oil cooler. For this reason, for example, when the vehicle body is started at a low temperature, the electric fan 26 is not driven, thereby facilitating the temperature rise of the electric heater 20 and increasing the rate at which the air temperature rises.

[0048] Next, Fig. 10 shows a second embodiment of the present invention. The second embodiment is characterized in that the electric heater is directly attached to the oil tank. In the second embodiment, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0049] The oil tank 31 of the second embodiment is configured almost similarly to the oil tank 14 of the first embodiment. Therefore, the oil tank 31 includes a front plate 31A, a rear plate 31B, a left plate 31C, a right plate 31D, a top plate 31E, and a bottom plate 31F. However, in the second embodiment, a thread is cut into the left plate 31C of the oil tank 31, and the electric heater 20 is fastened to the oil tank 31 by a bolt 21. In this case, a sealant or a seal washer is used on the threaded portion of the oil tank 31 to prevent oil leakage from the oil tank 31.

[0050] Thus, the second embodiment thus configured can also provide the same effects as the first embodiment. In the second embodiment, the electric heater 20 is directly fastened to the oil tank 31. Therefore, in the second embodiment, the amount of heat transferred from the oil tank 31 to the electric heater 20 is greater than in the first embodiment, and the temperature rise speed of the electric heater 20 can be increased.

[0051] In the above-described embodiments, the electric heater 20 is attached to a position facing the left face plate 14C, 31C of the oil tank 14, 31. The present invention is not limited to this, and the electric heater may be attached to another position on the oil tank as long as heat from the oil tank is conducted to the electric heater.

[0052] In addition, in each of the above embodiments, a rear ultra-tight turning hydraulic excavator equipped with a crawler-type lower traveling body 2 has been taken as an example of the hydraulic electric construction machine. However, the present invention is not limited to this, and can be widely applied to hydraulic electric construction machines such as ultra-tight turning hydraulic excavators, standard specification hydraulic excavators, wheeled hydraulic excavators, hydraulic cranes, etc. [Explanation of symbols]

[0053] 1. Electric hydraulic excavator (hydraulic electric construction machine) 2 Undercarriage (car body) 4. Upper rotating body (car body) 7 Cab 8 Driver's seat 11 Electric motor 12 Hydraulic pump 14,31 Oil tank 15 Temperature Sensor 16 Oil cooler 17 Bracket 20 Electric heater 23 Air Conditioning Unit 26 Electric fan (oil cooler cooling fan)

Claims

1. A vehicle body having a driver's seat; A hydraulic actuator provided on the vehicle body; a hydraulic pump that discharges pressure oil for driving the hydraulic actuator; an oil tank for supplying hydraulic oil to the hydraulic pump; an electric motor that drives the hydraulic pump; In a hydraulic electric construction machine equipped with An electric heater for heating the driver's seat is provided, the electric heater is disposed adjacent to the oil tank with a main surface facing the oil tank, A hydraulic electric construction machine characterized in that the temperature is increased by heat transfer from the oil tank.

2. An oil cooler for cooling the hydraulic oil returning to the oil tank; an oil cooler cooling fan that supplies cooling air to the oil cooler, 2. The hydraulic electric construction machine according to claim 1, wherein the oil tank is disposed between the electric heater and the oil cooler cooling fan.

3. A temperature sensor provided in the oil tank for detecting a temperature of the hydraulic oil; A control device that controls the rotation speed of the oil cooler cooling fan based on a signal from the temperature sensor, 2. The hydraulic electric construction machine according to claim 1, wherein the control device stops rotation of the oil cooler cooling fan when the electric heater is being driven and the temperature detected by the temperature sensor is equal to or lower than a set temperature.

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