JP2013082260A - Heating system for work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress power consumption in a heating system for a work machine.SOLUTION: The heating system includes: a radiator 111 provided inside a cabin 280; a water tank 120 (a container) for storing hot water W etc.; a circulation pipe line 130 for circulating the hot water W etc. between the radiator 111 and the water tank 120; a pump 134 which makes the hot water W etc. flow to the radiator 111 in a feed pipe line 131 in the circulation pipe line 130; a heat exchanger 140 which is provided to a return pipe line 132 (duct line) in the circulation pipe 130, and which performs heat exchange with the hot water W by supplying heat of a hydraulic fluid R being an external heat source; opening/closing valves 171 and 172 (switching means) for performing switching between execution/non-execution of heat exchange by the heat exchanger 140. The power consumption in an electric heater 121 is suppressed by heating the water W etc. supplied to the water tank 120 beforehand by the heat exchanger 140.

Description

  The present invention relates to a heating device for a work machine, and more particularly, to a heating device used for an electric work machine that is not provided with an engine (a prime mover such as an internal combustion engine) and that is supplied with electric power from an external or vehicle-mounted battery.

  Conventionally, a work machine such as a hydraulic excavator has been driven by using an engine as a power source. However, in recent years, an electric motor such as a three-phase induction motor is provided instead of the engine, and electric power is supplied to the electric motor from an external or vehicle-mounted battery. A so-called electric work machine that drives the work machine by supplying the power is widely put into practical use.

  Since this electric work machine is not equipped with an engine, there is an advantage that no exhaust gas is generated and that no sound is generated.

  By the way, the heating device provided in the operator's cab of the work machine uses an engine as a power source. By passing warm water (engine cooling water) warmed by the engine through the radiator of the heating device, The required warm air was obtained.

  However, since electric and battery-powered work machines do not have an engine, a water storage tank (container) equipped with an electric heater is provided and the water in the water storage tank is heated by this electric heater, which is required for a heating device. Hot water is produced only for this purpose (Patent Document 1).

JP 2003-267037 A

  By the way, in the prior art described above, since the electric heater is driven by an external power source or a battery, when using the heating device, electric power more than that required for driving the work machine is consumed.

  This invention is made | formed in view of the said situation, and it aims at providing the heating apparatus for working machines which can suppress the electric power consumed.

  The work machine heating device according to the present invention is preheated with a liquid such as water supplied to a container provided with an electric heater by a heat exchanger to which heat generated by an existing external heat source is supplied. It suppresses the amount of heat generated by the electric heater and suppresses power consumption.

  That is, the work machine heating device according to the present invention includes a radiator provided inside a cab of the work machine, a container that contains a liquid, an electric heater, and the radiator and the container. Heat exchange with the liquid by supplying heat generated by an external heat source provided in a circulation path for circulating the liquid between the pipe and a pipe line from the radiator to the container in the circulation path And a switching means for switching between execution and non-execution of heat exchange by the heat exchanger.

  According to the working machine heating device of the present invention, it is possible to suppress power consumption.

It is the perspective view which permeate | transmitted and represented some electric hydraulic shovels as an example of the working machine with which the heating apparatus for working machines which concerns on this invention is applied. It is the top view which showed typically the principal part in the upper revolving body of the electric hydraulic shovel shown in FIG. 1A. It is a block diagram which shows the structure of the heating apparatus for work machines applied to the electric hydraulic shovel shown in FIG. It is a principal part block diagram which shows only the component which replaced the two on-off valves in the heating apparatus shown in FIG. 2 with the single switching valve. It is a figure which shows embodiment of the structure which replaced the heat exchanger with which the circulation line side was equipped in the heating apparatus shown in FIG. 2 at the side of detour piping. It is a principal part block diagram which shows only the component which replaced the two on-off valves in the heating apparatus shown to FIG. 4A with the single switching valve. It is a block diagram which shows the structure of embodiment which applied the heat pipe as a heat exchanger.

  Hereinafter, an embodiment according to a heating device for a work machine of the present invention will be described with reference to the drawings.

  FIG. 1A is a perspective view showing a part of an electric excavator 200 as an example of a work machine, and FIG. 1B is a schematic view of a main part of the upper swing body 220 of the electric excavator 200 shown in FIG. 1A. FIG. 2 is a block diagram showing a configuration of a work machine heating device 100 (hereinafter simply referred to as the heating device 100) for heating the inside of the cab (operating chamber) of the electric excavator 200. FIG.

  The illustrated electric excavator 200 includes a lower traveling body 210 and an upper revolving body 220 provided so as to be able to swivel with respect to the lower traveling body.

  The upper swing body 220 sends hydraulic oil R to a boom, an arm, a bucket, a working device 230 including a boom cylinder, an arm cylinder, a bucket cylinder, and the like, a boom cylinder, an arm cylinder, a bucket cylinder, and other actuators. A hydraulic pump 240, a hydraulic oil tank 250 (external heat source) that temporarily stores hydraulic oil R supplied to the hydraulic pump 240, and an electric motor 260 as a power source that drives the hydraulic pump 240 are provided.

  The electric motor 260 is, for example, a three-phase induction motor, but is not limited to this type.

  Further, the electric motor 260 is supplied with electric power from the power supply 300 provided outside the electric excavator 200 via the power supply cable 270 and is driven by this electric power. The supply of electric power to the electric motor 260 is not limited to the power supply 300 provided outside, but may be a battery mounted on the vehicle body.

  An upper slewing body 220 of the electric excavator 200 is further formed with a cab 280 in which an operator who operates the work apparatus is boarded.

(Embodiment 1)
As shown in FIG. 2, the heating device 100 according to the present embodiment is a heat transfer unit that includes a heat radiator 111 provided in the cab 280 and an electric fan 112 that blows air to the heat radiator 111, and a heat transfer medium. As a circulation path for circulating hot water or the like W between a warm water tank 120 (container) containing water or warm water W (hereinafter simply referred to as hot water or the like W) which is an example of a liquid, and the radiator 111 and the hot water tank 120. The circulation pipe 130 (circulation path).

  In addition, the heating device 100 is provided in a feed pipe 131 between the hot water tank 120 and the radiator 111 in the circulation pipe 130, and feeds warm water or the like W in the hot water tank 120 toward the radiator 111. A pump 134 and a heat exchanger 140 provided in a return pipe 132 (pipe) from the radiator 111 to the hot water tank 120 where hot water or the like W is provided in the circulation pipe 130 are provided.

  And by blowing with the electric fan 112 to the radiator 111 through which warm water etc. W flows, the air blown is warmed while passing through the radiator 111, and the cab 280 is heated by the warmed air. It has become.

  Here, the hot water tank 120 is provided with an electric heater 121 for heating the hot water or the like W contained therein, and the hot water or the like W in the hot water tank 120 is heated by energizing the electric heater 121.

  The electric heater 121 is driven by the electric power supplied from the power supply 300 via the power supply cable 270, and switching between energization and de-energization of the electric heater 121 by switching connection / disconnection of the switch 122.

  In addition, the hot water tank 120 is provided with a temperature sensor 123 in the hot water tank that detects the temperature T3 of the hot water W or the like stored in the hot water tank 120.

  And even if the control apparatus 150 mentioned later is the temperature T3 detected by the temperature sensor 123 in a warm water tank, and the temperature T0 (specific value (fixed value) preset) requested | required in the cab 280 For example, an input interface capable of inputting an arbitrary temperature T0 value may be provided in the cab 280, and the value input to the input interface may be compared. Controls connection / disconnection switching.

  The heat exchanger 140 provided in the circulation line 130 is immersed in a hydraulic oil tank 250 in which existing hydraulic oil R, which is an example of an external heat source, is stored, and is used as a heat source. The heat of the hydraulic oil R in the oil tank 250 (heat generated by an external heat source) serves to increase the efficiency of warming the warm water W in the circulation line 130.

  In the drawing, the pipe line between the radiator 111 and the heat exchanger 140 in the return pipe line 132 is indicated as a return pipe line 132a, and the pipe line between the heat exchanger 140 and the hot water tank 120 is returned. It is displayed as a pipe line 132b.

  In addition, a hydraulic oil tank temperature sensor 141 (heat source temperature detector) that detects the temperature T2 of the hydraulic oil R stored in the hydraulic oil tank 250 is also provided in the hydraulic oil tank 250.

  Furthermore, a post-heat-dissipation temperature sensor 135 (after heat dissipation) that detects the temperature T1 of warm water or the like flowing in the return pipe 132a also in the return pipe 132a from the radiator 111 to the heat exchanger 140 in the circulation pipe 130. Temperature detector).

  The heating device 100 of the present embodiment configured as described above does not cover hot water or the like W, which is a heat source radiated by the radiator 111, only by the heat generated by the electric heater 121, but by hydraulic oil R that is an external heat source. The warming water W or the like W supplied to the hot water tank 120 is preliminarily heated to suppress the amount of heat generated by the electric heater 121, that is, the power consumption in the electric heater 121.

  The controller 150 compares the temperature T3 of the hot water W detected by the hot water tank temperature sensor 123 with the temperature T0 required in the cab 280, and the temperature T3 is higher than the temperature T0 (T3> T0). When the temperature T3 is lower than the temperature T0 (T3 <T0), the control device 150 controls the switch 122 to be connected.

  As described above, the controller 150 controls the electric heater 121 to be disconnected by disconnecting the switch 122 under the situation where the temperature T3 of the hot water W or the like in the hot water tank 120 is higher than the temperature T0 required by the radiator 111. Since heat is not generated, useless power consumption by the electric heater 121 can be prevented.

  Furthermore, the heating device 100 of the present embodiment is connected to the return pipe 132 by bypassing the portion where the hydraulic oil tank 250 is provided so that the hot water W or the like that has passed through the radiator 111 does not pass through the heat exchanger 140. Two on-off valves 171 and 172 (switching) that switch between a state where the hydraulic oil tank 250 and the state where the detour conduit 160 is passed, and the state where the hot water or the like W that has passed through the radiator 111 passes. Valve).

  Here, each of the two on-off valves 171 and 172 is formed so as to be movable between an open position allowing the flow of warm water or the like W and a closed position blocking the flow. The on-off valve 171 is moved to the open position and the other on-off valve 172 is moved to the closed position so that hot water or the like W that has passed through the radiator 111 passes through the heat exchanger 140, or one on-off valve 172 is moved to the open position, and the other on-off valve 171 is moved to the closed position so that the warm water or the like W that has passed through the radiator 111 passes through the bypass duct 160 (the state that does not allow the heat exchanger 140 to pass). It is said.

  Further, in place of the two on-off valves 171 and 172 provided for the respective pipelines 132 and 160, as shown in FIG. 3, a single switching valve 170 is provided at a branch portion of both the pipelines 132 and 160. It is good.

  In the control by the control device 150 in the heating device 100 of the present embodiment, the first temperature T1 detected by the post-heat dissipation temperature sensor 135 is higher than the second temperature T2 detected by the hydraulic oil tank temperature sensor 141. When (T1> T2), the on-off valve 171 is in the closed position and the on-off valve 172 is in the open position. On the other hand, when the first temperature T1 is lower than the second temperature T2 (T1 <T2) In this control, the on-off valve 171 is opened and the on-off valve 172 is closed.

  In the configuration including the switching valve 170 illustrated in FIG. 3, when the first temperature T1 is higher than the second temperature T2 (T1> T2), the control device 150 causes the switching valve 170 to When the first temperature T1 is lower than the second temperature T2 (T1 <T2), control is performed so that the hot water W passes through the bypass pipe 160, and the hot water etc. W is heated. Control to switch to pass through the exchanger 140 is performed.

  As described above, the control device 150 controls the opening and closing of the on-off valves 171 and 172 or the switching of the switching valve 170, so that it is possible to further suppress wasteful power consumption in the electric heater.

  The on-off valves 171 and 172 are not limited to those that can only be fully opened (the opening degree is 100%) as the opening degree in the open position, and can be changed continuously or stepwise. Good.

  In the case where the on-off valves 171 and 172 that can change the opening degree are applied in this way, the warm water or the like W that has passed through the radiator 111 is allowed to pass only through the bypass duct 160 or only through the heat exchanger 140. In addition to the alternative switching, the amount of hot water etc. W that passes through the bypass duct 160 out of the hot water etc. W that has passed through the radiator 111 by adjusting the opening degree of both the open / close valves 171 and 172, respectively. And the amount of hot water or the like W that passes through the heat exchanger 140 can be adjusted, and the temperature of the hot water or the like W that flows through the return pipe 132b can be finely adjusted.

  In addition, the switching valve 170 is switched between a state in which the hot water or the like W that has passed through the radiator 111 passes through the heat exchanger 140 and a state in which the bypass pipe 160 passes through, similarly to the two on-off valves 171 and 172. However, similar to the two on-off valves 171, 172, the hot water or the like W that has passed through the radiator 111 is allowed to pass only through the bypass duct 160 or only through the heat exchanger 140. In addition to the flow switching, the switching valve 170 is a diversion valve, so that the amount of hot water W passing through the bypass pipe 160 and the heat exchanger 140 out of the hot water W passing through the radiator 111 are changed. It is possible to adjust the ratio of the amount of warm water or the like to be passed through and finely adjust the temperature of the warm water or the like W that flows through the return pipe 132b.

  According to the heating device 100 of the present embodiment configured as described above, the control device 150 controls the opening / closing of the on-off valves 171 and 172 and the switching of the switching valve 170, thereby passing the radiator 111 and the hot water tank 120. Before the warm water W returned to the warm water tank 120 is returned to the hot water tank 120, it can be switched between a state where the heat exchanger 140 is passed and a state where it is not passed.

  Since the hydraulic oil R stored in the hydraulic oil tank 250 serving as a heat source is compressed by the hydraulic pump 240 and drives the working device 230, it is usually very high temperature. When the on-off valves 171 and 172 and the switching valve 170 are switched to a state in which hot water or the like W is passed through the heat exchanger 140, the passed hot water or the like W is warmed by the hydraulic oil R and is added to the hot water tank 120. As a result, the degree of heating by the electric heater 121 can be suppressed.

  On the other hand, for example, when the working device 230 has been stopped for a long time or the like, the temperature of the hydraulic oil R is relatively low. Especially at night in the winter season, since the hydraulic oil R is also cooled by the outside air or the like, when the warm water W returned through the radiator 111 and returned to the hot water tank 120 passes through the hydraulic oil tank 250, the warm water W is It will be cooled by the hydraulic oil R having a relatively low temperature, and the degree of warming of W such as hot water by the electric heater 121 in the hot water tank 120 will be increased.

  However, according to the heating device 100 of the present embodiment, the control device 150 allows the on-off valves 171, 172 and the switching valve 170 to pass warm water or the like W through the bypass duct 160 (state where the heat exchanger 140 is not passed). Since the warm water or the like W does not pass through the hydraulic oil tank 250, the warm water or the like W can be prevented from being cooled by the hydraulic oil R, thereby heating the warm water or the like W by the electric heater 121. Can be prevented from increasing.

  Although the heating apparatus 100 of the above-described embodiment has been described as having the hydraulic oil tank 250 (hydraulic oil R) as a heat source provided in the circulation line 130, for example, as a configuration obtained by modifying an existing heating apparatus for work machines When capturing the working machine heating device of the present invention, as shown in FIG. 4A, the detour pipeline 160 having the hydraulic oil tank 250 is connected to the existing circulation pipeline 130 (return pipeline 132), The on / off valves 171 and 172 (in FIG. 4B, a single switching valve 170) are provided in the vicinity of the connection portion between the two pipe lines 132. However, the existing circulation pipe 130 is regarded as a bypass pipe and the bypass pipe is used. This corresponds to an embodiment of the heating device for a work machine according to the present invention in which the path 160 is regarded as a circulation pipe line.

(Embodiment 2)
In the heating apparatus 100 according to the above-described embodiment, whether or not the bypass pipe 160 and the on-off valves 171 and 172 or the switching valve 170 pass the hydraulic oil tank 250 (hydraulic oil R) using hot water or the like W as a heat source. Although the switching means for switching whether or not the warm water W or the like in the return pipe 132 is warmed before the heating by the electric heater 121 is configured, the work machine heating apparatus of the present invention is such a switching means. Is not limited to switching between implementation and non-execution of warming of warm water or the like in the return pipe 132 by the hydraulic oil tank 250, for example, the heat exchanger itself performs implementation or non-execution of the heat exchange operation. It may also serve as a function of switching means for switching.

  That is, the heating device 100 ′ according to the second embodiment can apply the heat pipe 180 including the heat receiving unit 182 and the heat radiating unit 183 as a heat exchanger, for example.

  In the heating apparatus 100 ′ to which the heat pipe 180 is applied as the heat exchanger, the heat receiving portion 182 of the heat pipe 180 is immersed in the hydraulic oil R of the existing hydraulic oil tank 250 as shown in FIG. In the circulation line 130, the return line 132 through which the warm water W is returned from the radiator 111 to the hot water tank 120 is wound around the heat dissipating part 183.

  The heat pipe 180 is disposed at an inclination or vertically, and performs heat release from the heat receiving unit 182 to the heat radiating unit 183 when the heat receiving unit 182 is lower than the heat radiating unit 183. In other words, when the temperature of the heat receiving unit 182 at a position lower than the heat radiating unit 183 is lower than the temperature of the heat radiating unit 183, heat is not released from the heat receiving unit 182 to the heat radiating unit 183.

  For this reason, when the temperature of the heat receiving part 182 located on the lower side is higher than the temperature of the heat radiating part 183 located on the upper side, the heat received by the heat receiving part 182 is transmitted to the heat radiating part 183. When the temperature of the part 182 is lower than the temperature of the heat radiating part 183, the heat received by the heat receiving part 182 is not transferred to the heat radiating part 183, so that the heat pipe 180 itself automatically switches between performing and not performing the heat exchange operation. Can do. That is, the heat pipe 180 has a function of a control unit that controls the switching unit and the switching unit.

  Therefore, also with the heating device 100 ′ having the configuration shown in FIG. 5, the hot water W or the like W that passes through the radiator 111 and is returned to the hot water tank 120 is transferred to the hot water tank 120, as in the heating device 100 shown in FIG. 2. Before returning, it is possible to switch whether or not to warm W or the like W by switching between performing and not performing the heat exchange operation.

  Since the hydraulic oil R stored in the hydraulic oil tank 250 is compressed by the hydraulic pump 240 and drives the working device 230 and the like, the hydraulic oil R is usually very hot, and the temperature is such as hot water W or the like. When the temperature T2 is higher than the temperature T1, the heat receiving portion 182 of the heat pipe 180 has a higher temperature than the heat radiating portion 183, and thus heat exchange (heat release) by the heat pipe 180 is performed.

  That is, the heat pipe 180 in which the heat receiving portion 182 is immersed in the high temperature hydraulic oil R stored in the hydraulic oil tank 250 transmits the heat received by the heat receiving portion 182 to the heat radiating portion 183, and The warm water or the like W that has passed through the return pipe 132 provided by being wound is heated by the heat transmitted to the heat radiating unit 183 and flows into the warm water tank 120, thereby suppressing the degree of heating by the electric heater 121. It becomes possible.

  On the other hand, the temperature of the hydraulic oil R is relatively low when starting or when the working device 230 has been stopped for a long time. In particular, during the winter and at night, the hydraulic oil tank 250 itself is also cooled by the outside air, and the temperature may be lower than the temperature T1 of W such as hot water.

  At that time, since the heat receiving part 182 of the heat pipe 180 has a temperature lower than that of the heat radiating part 183, heat exchange by the heat pipe 180 is not performed.

  Therefore, warm water or the like W that has passed through the return pipe 132 provided in the heat radiating unit 183 returns to the hot water tank 120 without being cooled at a low temperature of the heat receiving unit 182, and is about the degree of heating by the electric heater 121. An increase can be prevented.

  The heat pipe 180 can adjust the degree of heat transfer from the heat receiving unit 182 to the heat radiating unit 183 according to the angle of inclination with respect to the horizontal plane in the posture.

  That is, the degree of heat transfer from the heat receiving unit 182 to the heat radiating unit 183 can be increased as the inclination angle approaches 90 [deg].

  The heating devices 100 and 100 ′ according to the above-described embodiments apply the hydraulic oil R as an external heat source. However, the working machine heating device according to the present invention externally uses an existing heat source other than the hydraulic oil R. It can also be applied as a heat source.

  In this case, if the temperature is higher than the temperature of W such as hot water flowing through the return pipe 132 of the circulation pipe 130 in a normal operation state in which the work machine is operated, the heat source can be applied.

  The working machine to which the heating devices 100 and 100 ′ of the present embodiment are applied is the hydraulic excavator 200, but the working machine to which the working machine heating device according to the present invention is applied is not limited to the hydraulic excavator. In addition, various work machines such as a wheel loader and a crane truck can be applied.

  In addition, the working machine to which the heating devices 100 and 100 ′ of the present embodiment are applied is an electric excavator 200, but the working machine to which the working machine heating device according to the present invention is applied receives power from an external power source. It is not limited to what is supplied, but a battery-driven type can also be applied.

100,100 'heating device (heating device for work machine)
111 Heat Dissipator 120 Hot Water Tank 121 Electric Heater 122 Switch 130 Circulation Line (Circulation Path)
131 Feed lines 132, 132a, 132b Return line 134 Pump 140 Heat exchanger 150 Controller 160 Detour line (detour)
171, 172 On-off valve 180 Heat pipe 250 Hydraulic oil tank 270 Power supply cable 280 Driver's cab 300 Power supply R Hydraulic oil T0, T1, T2, T3 Temperature W Hot water, etc. (water or hot water)

Claims (5)

A radiator provided in the cab of the work machine;
A container with an electric heater for containing the liquid;
A circulation path for circulating the liquid between the radiator and the container;
A heat exchanger that is provided in a pipe line from the radiator to the container in the circulation path and that is supplied with heat generated by an external heat source and exchanges heat with the liquid;
A working machine heating device comprising switching means for switching between implementation and non-execution of heat exchange by the heat exchanger.   The switching means bypasses the heat exchanger so that the liquid that has passed through the radiator does not pass through the heat exchanger and passes through a detour connected to the circulation path, and the radiator The work machine heater according to claim 1, further comprising a switching valve that switches between the liquid that has passed and a state in which the liquid passes through the heat exchanger. A post-heat dissipation temperature detector for detecting the temperature of the liquid in a pipe line from the radiator to the heat exchanger in the circulation path;
A heat source temperature detector for detecting the temperature of the heat source;
When the first temperature detected by the post-heat radiation temperature detector is higher than the second temperature detected by the heat source temperature detector, the switching means is switched to the non-execution side of the heat exchange, The operation according to claim 1, further comprising: a control device that switches the switching unit to the heat exchanging side when the first temperature is lower than the second temperature. Mechanical heating device.   The heat exchanger and the switching means are heat pipes provided with a heat receiving part and a heat radiating part, the heat receiving part is arranged in the external heat source, and the heat radiating part is higher than the heat receiving part, The work machine heater according to claim 1, wherein the work machine heater is wound around a circulation path from the radiator toward the container.   The heating device for a working machine according to any one of claims 1 to 4, wherein the external heat source is a hydraulic oil tank.