JP2014125868A - Counterweight, construction machinery, and control method for construction machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide construction machinery that comprises a counterweight capable of more efficiently releasing heat of a heat source mounted in the construction machinery.SOLUTION: A shovel relating to an embodiment of the present invention includes a diesel engine 8, a counterweight 2a, and a vessel 40 that circulates a cooling medium for cooling the diesel engine 8, The vessel 40 includes a vessel part 41 that passes through the counterweight 2a. Additionally, the vessel part 41 has a radiator plate 41c, and working for increasing a surface area is applied to a surface of the counterweight 2a.

Description

  The present invention relates to a counterweight mounted on a construction machine having a heat source, a construction machine mounted with a heat source and a counterweight, and a control method thereof.

  Conventionally, in order to prevent the engine from overheating, an excavator including a heat exchanger unit including a cooling fan and a radiator is known.

  However, the conventional excavator does not have a device that performs positive cooling other than the heat exchanger unit including the fan and the radiator. For this reason, the engine heat cannot be radiated more efficiently than improving the performance of the fan or the radiator.

  The present invention has been made in view of the above points, a counterweight capable of more efficiently dissipating the heat of a heat source mounted on a construction machine to the outside, a construction machine equipped with such a counterweight, and An object is to provide a control method thereof.

  In order to achieve the above object, a construction machine according to an embodiment of the present invention is a construction machine including a heat source, a counterweight, and a conduit for circulating a cooling medium that cools the heat source. A conduit portion extending through the counterweight.

  The counterweight according to the embodiment of the present invention is a counterweight through which a conduit for circulating a cooling medium for cooling a heat source mounted on a construction machine passes.

  A construction machine control method according to an embodiment of the present invention passes through a heat source, a counterweight, a conduit for circulating a cooling medium for cooling the heat source, and a conduit portion passing through the counterweight among the conduits. A control method for a construction machine, comprising: a switching valve that switches between a flow path and a flow path that bypasses the conduit portion, wherein the temperature detection step detects the temperature of the cooling medium, and is detected in the temperature detection step And a switching valve control step for controlling the switching valve based on temperature.

  By the means described above, the present invention provides a counterweight capable of more efficiently dissipating heat from a heat source mounted on a construction machine, a construction machine equipped with such a counterweight, and a control method thereof. it can.

It is a side view of the shovel which is an example of a construction machine. It is a schematic plan view of an upper swing body. It is a permeation | transmission perspective view which shows the structural example of a counterweight. It is a figure which shows the structural example of the exhaust gas purification system of the shovel of FIG. It is FIG. (1) explaining the flow of the cooling medium in the conduit | pipe for cooling medium. It is FIG. (2) explaining the flow of the cooling medium in the conduit | pipe for cooling medium. FIG. 6 is a third diagram illustrating the flow of the cooling medium in the cooling medium conduit. It is detail drawing of a switching valve. It is the perspective view and sectional drawing which show the structural example of a counterweight.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing an excavator as an example of a construction machine. As shown in FIG. 1, an upper swing body 2 is mounted on the lower traveling body 1 so as to be swingable, and a cab 3 is provided on one front side of the upper swing body 2. Further, the boom 4 is pivotally attached to the front center portion of the upper swing body 2 so that the boom 4 can be raised and lowered, and an arm 5 is connected to the tip portion of the boom 4 so as to be vertically rotatable. Is attached to be rotatable up and down. The excavation attachment may be another attachment such as a breaker or a crusher.

  FIG. 2 is a plan view schematically showing the rear part of the upper swing body 2 in a top view. As shown in FIG. 2, an engine room 7 is formed at the rear of the upper swing body 2, and a diesel engine 8 is installed in the engine room 7. A cooling fan 12 is provided on the left side (lower side in FIG. 2) of the diesel engine 8, and a heat exchanger unit 13 including a radiator and the like is installed on the left side of the cooling fan 12.

  Further, an exhaust pipe 9 is connected to the diesel engine 8 via a turbocharger 15, and an exhaust gas purification system 20 is installed on the downstream side of the exhaust pipe 9 in order to comply with higher-order exhaust gas regulations. As the exhaust gas purification system 20, a urea selective reduction type NOx treatment apparatus using a urea aqueous solution (liquid reducing agent) is adopted. In addition to the dosing module 21, the exhaust gas purification system 20 includes an SCR (Selective Catalytic Reduction) catalyst and an oxidation catalyst (DOC: Diesel Oxidation Catalyst) that burns unburned fuel contained in particulate matter (PM). May include. Further, the diesel engine 8 has an intake pipe 11 connected to the heat exchanger unit 13 via the turbocharger 15. Air is introduced into the diesel engine 8 through the intake pipe 11.

  The cooling medium conduit 40 is a conduit for circulating the cooling medium between the diesel engine 8 and the heat exchanger unit 13. In the present embodiment, the cooling medium conduit 40 connects the conduit portion 41 penetrating through the counterweight 2 a, the conduit portion 42 connecting the conduit portion 41 and the heat exchanger unit 13, and the conduit portion 41 and the diesel engine 8. A conduit portion 43 and a conduit portion 44 connecting the heat exchanger unit 13 and the water pump 14 are included.

  The cooling medium is a medium for cooling the heat source, and may be a gas or a liquid. In the present embodiment, radiator cooling water for cooling the diesel engine 8 as a heat source is used.

  The water pump 14 is a device for circulating a cooling medium in the conduit 40, and is driven via a pulley and a timing belt 8b attached to the shaft 8a of the diesel engine 8.

  In addition, the counterweight 2a may be provided with a member for suppressing heat radiation, such as a heat insulating material, on the surface facing the engine room 7. This is for preventing the heat of the counterweight 2a from returning to the engine room 7 and for promoting the heat of the counterweight 2a to be radiated to the outside through the outer surface of the counterweight 2a.

  FIG. 3 is a transparent perspective view of the counterweight 2a when viewed from the back of the excavator. As shown in FIG. 3, the conduit portion 41 of the cooling medium conduit 40 enters the counterweight 2a at the inlet 41a and exits the counterweight 2a at the outlet 41b. Further, in FIG. 3, for the sake of clarity, the illustration of the filler of the counterweight 2 a is omitted, but the conduit portion 41 is actually embedded in the filler. The filler is a material filled in the counterweight 2a in order to adjust the weight of the counterweight 2a, and includes, for example, concrete, asphalt, a metal lump, and the like. In this embodiment, the filling material is filled in the counterweight 2a so as to embed the entire conduit portion 41, but may be filled so that a part of the conduit portion 41 is exposed.

  Moreover, the conduit | pipe part 41 is formed with a material with high heat conductivity, such as a metal, so that the heat of the cooling medium which flows through the inside may be easily transmitted to the counterweight 2a. Moreover, the conduit | pipe part 41 contains the several heat sink 41c made from the material with high heat conductivity so that the heat of the cooling medium which flows through the inside may become easy to be transmitted to the counterweight 2a. In the present embodiment, the main body of the conduit portion 41 and the heat radiating plate 41c are formed of the same material, but may be formed of different materials. In the present embodiment, the plurality of heat radiating plates 41c are embedded in the filler together with the main body of the conduit portion 41, but some of them may be exposed from the filler.

  Further, the pipe diameter, pipe thickness, length, piping layout, and the like of the conduit portion 41 are determined based on the desired temperature of the cooling medium entering the heat exchanger unit 13, the performance of the water pump 14, and the like. In addition, the conduit | pipe part 41 may have the same pipe diameter over the full length, and may have a partially different pipe diameter. A honeycomb core may be installed inside the conduit portion 41. This is because the heat of the cooling medium is easily transmitted to the counterweight 2a.

  Next, the exhaust gas purification system 20 mounted on the excavator of FIG. 1 will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating an example of the exhaust gas purification system 20. In the present embodiment, the exhaust gas purification system 20 purifies the exhaust gas discharged from the diesel engine 8.

  The diesel engine 8 is driven by fuel supplied from a fuel tank (not shown) by a high pressure pump, and directly injects and burns the high pressure fuel into the combustion chamber. The diesel engine 8 and the high-pressure pump are controlled by an engine control module (hereinafter referred to as “ECM”) 31.

  Exhaust gas from the diesel engine 8 passes through the turbocharger 15, reaches the exhaust pipe 9 downstream thereof, is purified by the exhaust gas purification system 20, and is discharged into the atmosphere.

  On the other hand, the intake air introduced from the air cleaner 10 into the intake pipe 11 is supplied to the diesel engine 8 through the turbocharger 15 and the heat exchanger unit 13.

  A diesel particulate filter 28 that collects PM in the exhaust gas and a selective reduction type NOx catalyst 29 for selective catalytic reduction that reduces and removes NOx in the exhaust gas are connected in series to the exhaust pipe 9 from the upstream side. Is provided.

  The selective reduction type NOx catalyst 29 receives a supply of a liquid reducing agent (for example, urea or ammonia) and continuously reduces and removes NOx in the exhaust gas. In this embodiment, urea water (urea aqueous solution) is used as a liquid reducing agent for ease of handling.

  A dosing module 21 for supplying urea water to the selective reduction type NOx catalyst 29 is provided upstream of the selective reduction type NOx catalyst 29 in the exhaust pipe 9. The dosing module 21 is, for example, a urea water injection valve, and is connected to a urea water tank 24 (liquid reducing agent tank) via a urea water supply line 22.

  The urea water supply line 22 is provided with a urea water supply pump 23. The urea water stored in the urea water tank 24 is supplied to the dosing module 21 by the urea water supply pump 23 and is injected from the dosing module 21 to the upstream position of the selective reduction type NOx catalyst 29 in the exhaust pipe 9.

  The urea water injected from the dosing module 21 is supplied to the selective reduction type NOx catalyst 29. The supplied urea water is hydrolyzed in the selective reduction type NOx catalyst 29 to generate ammonia. This ammonia reduces the NOx contained in the exhaust gas in the selective reduction type NOx catalyst 29, thereby purifying the exhaust gas.

  The first NOx sensor 26 is disposed on the upstream side of the dosing module 21. The second NOx sensor 27 is disposed downstream of the selective reduction NOx catalyst 29. The NOx sensors 26 and 27 detect the NOx concentration in the exhaust gas at the respective arrangement positions.

  A urea water remaining amount sensor 25 is disposed in the urea water tank 24. The urea water remaining amount sensor 25 detects the urea water remaining amount in the urea water tank 24.

  The NOx sensors 26, 27, the urea water remaining amount sensor 25, the dosing module 21, and the urea water supply pump 23 are connected to the exhaust gas purification system controller 32. The exhaust gas purification system controller 32 performs injection amount control so that an appropriate amount of urea water is injected by the dosing module 21 and the urea water supply pump 23 based on the NOx concentration detected by the NOx sensors 26 and 27.

  The exhaust gas purification system controller 32 is connected to an ECM 31 that controls the diesel engine 8 by communication means. The ECM 31 is connected to the excavator controller 30 by communication means.

  The shovel controller 30 is a main control unit that performs drive control of the shovel. In this embodiment, the excavator controller 30 is a computer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output port, a storage device, and the like.

  Various types of information of the exhaust gas purification system 20 included in the exhaust gas purification system controller 32 can be shared by the excavator controller 30. The ECM 31 and the exhaust gas purification system controller 32 include a CPU, a RAM, a ROM, an input / output port, a storage device, and the like, respectively, similarly to the excavator controller 30.

  Next, an example of the flow of the cooling medium in the cooling medium conduit will be described with reference to FIG. FIG. 5 is a plan view schematically showing the rear part of the upper swing body 2 in a top view, and corresponds to FIG.

  As shown in FIG. 5, the coolant in the relatively hot state leaving the diesel engine 8 passes through the conduit portion 43 to the conduit portion 41 that penetrates the counterweight 2 a. When the cooling medium in a relatively high temperature state passes through the conduit portion 41, the temperature of the cooling medium is lowered by moving the heat held by the cooling medium to the counterweight 2a. Then, after leaving the conduit portion 41, the cooling medium that has become relatively cool enters the heat exchanger unit 13 through the conduit portion 42. The cooling medium further cooled in the heat exchanger unit 13 is sucked into the water pump 14 and introduced into the diesel engine 8 through the conduit portion 44.

  With this configuration, the shovel according to the present embodiment can lower the temperature of the cooling medium that leaves the diesel engine 8 and returns to the heat exchanger unit 13 by using the entire counterweight 2a as a radiator. As a result, the diesel engine 8 can be cooled more efficiently. Further, the burden on the heat exchanger unit 13 can be reduced, and as a result, the radiator can be reduced in size, the cooling fan 12 can be reduced, the number of rotations of the cooling fan 12 can be reduced, and energy can be saved.

  Next, another example of the flow of the cooling medium in the cooling medium conduit will be described with reference to FIG. FIG. 6 is a plan view schematically showing the rear part of the upper swing body 2 in a top view, and corresponds to FIG.

  In this embodiment, the cooling medium conduit 40A circulates a cooling medium for cooling the dosing module 21 as a heat source, instead of circulating a cooling medium for cooling the diesel engine 8 as a heat source. The dosing module 21 does not generate heat by itself, but can be a heat source because it is adjacent to the exhaust pipe 9 heated by the exhaust gas. Specifically, as shown in FIG. 6, the cooling medium in a relatively hot state exiting a conduit portion (not shown) disposed in the dosing module 21 to cool the dosing module 21 is The conduit portion 43A is passed through to the conduit portion 41 penetrating the counterweight 2a. When the cooling medium in a relatively high temperature state passes through the conduit portion 41, the temperature of the cooling medium is lowered by moving the heat held by the cooling medium to the counterweight 2a. Then, after leaving the conduit portion 41, the cooling medium that has become in a relatively low temperature state is sucked into the sub-pump 16 through the conduit portion 42 </ b> A and then introduced into the dosing module 21 again.

  With this configuration, the shovel according to the present embodiment can reduce the temperature of the cooling medium that cools the dosing module 21 without using the heat exchanger unit 13 by using the entire counterweight 2a as a radiator. . As a result, the conduit system in which the cooling medium for cooling the dosing module 21 circulates can be separated from the conduit system in which the cooling medium for cooling the diesel engine 8 circulates.

  Next, another example of the flow of the cooling medium in the cooling medium conduit will be described with reference to FIGS. 7 and 8. FIG. 7 is a plan view schematically showing the rear part of the upper swing body 2 in a top view, and corresponds to FIG. FIG. 8 is an enlarged view of a region VIII in FIG.

  In the present embodiment, the cooling medium in a relatively high temperature state leaving the diesel engine 8 reaches the switching valve 50 through the conduit portion 47B.

  The switching valve 50 is a valve that switches between a flow path that passes through the conduit portion 41 and a flow path that bypasses the conduit portion 41. In the present embodiment, the switching valve 50 switches between the first position and the second position according to the control current from the excavator controller 30. Specifically, the switching valve 50 has a first position (see FIG. 8A) for connecting the conduit portion 47B to the conduit portion 43B, and a second position (FIG. 8) for connecting the conduit portion 47B to the conduit portion 45B. (See (B)). When the switching valve 50 is in the first position, the relatively hot coolant exiting the conduit portion in the diesel engine 8 passes through the counterweight 2a through the conduit portion 47B and the conduit portion 43B. To. Then, the cooling medium exiting the conduit portion 41 reaches the heat exchanger unit 13 through the conduit portion 42B and the conduit portion 45B. On the other hand, when the switching valve 50 is in the second position, the coolant that is in a relatively hot state leaving the diesel engine 8 reaches the heat exchanger unit 13 through the conduit portion 47B and the conduit portion 45B.

  In the present embodiment, the excavator controller 30 includes a temperature detection unit 300 and a switching valve control unit 301 as functional elements.

  The temperature detection unit 300 is a functional element that detects the temperature of the cooling medium. In the present embodiment, the temperature detection unit 300 detects the temperature of the cooling medium based on the output of the temperature sensor 51 installed at the conduit portion 47B. The temperature detection unit 300 is a cooling medium based on the output of a temperature sensor (not shown) installed in other parts such as the diesel engine 8, the heat exchanger unit 13, the conduit parts 44 and 45B, the water pump 14, and the like. The temperature may be detected.

  The switching valve control unit 301 is a functional element that controls the switching valve 50. In the present embodiment, the switching valve control unit 301 controls the switching valve 50 based on the temperature of the cooling medium detected by the temperature detection unit 300. Specifically, the switching valve control unit 301 determines whether or not the temperature of the cooling medium is equal to or higher than a predetermined temperature. When the switching valve control unit 301 determines that the temperature of the cooling medium is equal to or higher than the predetermined temperature, the switching valve control unit 301 outputs a control current to the switching valve 50 and switches the switching valve 50 to the first position. This is because a coolant having a temperature equal to or higher than a predetermined temperature leaving the diesel engine 8 is caused to flow through the conduit portion 41 and the temperature of the coolant entering the heat exchanger unit 13 is reduced. Thereby, it can avoid that the burden of the heat exchanger unit 13 increases. On the other hand, when the switching valve control unit 301 determines that the temperature of the cooling medium is lower than the predetermined temperature, the switching valve control unit 301 stops outputting the control current to the switching valve 50 and switches the switching valve 50 to the second position. This is because a coolant having a temperature lower than the predetermined temperature leaving the diesel engine 8 is allowed to flow to the heat exchanger unit 13 without flowing to the conduit portion 41. Thereby, it can avoid that the burden of the water pump 14 increases.

  With this configuration, the shovel according to the present embodiment can select whether or not to use the entire counterweight 2a as a radiator according to the temperature of the cooling medium. As a result, optimum heat dissipation according to the temperature of the cooling medium can be executed, and energy saving can be achieved.

  Next, a count weight 2a1 that is another example of the counter weight according to the embodiment of the present invention will be described with reference to FIG. 9A is a perspective view of the counterweight 2a1, and FIG. 9B is a cross-sectional view along the plane XIB of FIG. 9A.

  As shown in FIGS. 9A and 9B, the outer surface 2a2 of the counterweight 2a1 is embossed to increase the surface area, and the thermal conductivity is increased. . Therefore, the shovel according to the present embodiment can dissipate the heat transferred from the cooling medium to the counterweight 2a1 through the conduit portion 41 of the cooling medium conduit more efficiently.

  The outer surface 2a2 of the counterweight 2a1 may be subjected to other known processing for increasing the surface area instead of embossing.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications, changes, and the like are within the scope of the present invention described in the claims. Is possible.

  For example, in the above-described embodiment, the conduit portion 41 of the cooling medium conduit 40 is disposed downstream of the diesel engine 8 and upstream of the heat exchanger unit 13, but the present invention is not limited thereto. The conduit portion 41 may be disposed downstream of the heat exchanger unit 13 and upstream of the water pump 14, and may be disposed downstream of the water pump 14 and upstream of the diesel engine 8.

  In the above-described embodiment, the cooling medium conduit 40 </ b> A separates the conduit system through which the cooling medium for cooling the dosing module 21 circulates and the conduit system through which the cooling medium for cooling the diesel engine 8 circulates. However, the present invention is not limited to this. The cooling medium conduit 40 </ b> A may be a combination of a conduit system in which a cooling medium for cooling the dosing module 21 circulates and a conduit system in which a cooling medium for cooling the diesel engine 8 circulates. That is, the cooling medium of the two conduit systems may be shared. In this case, the piping layout is arbitrary. For example, the downstream side of the conduit portion 42A may be connected to the heat exchanger unit 13, and the downstream side of the conduit portion 45A may be connected to the sub pump 16.

  In the above-described embodiment, the switching valve 50 alternatively switches between a flow path that passes through the conduit portion 41 and a flow path that bypasses the conduit portion 41. However, the present invention is not limited to this. The switching valve 50 may be configured such that a part of the cooling medium flows in the flow path passing through the conduit portion 41 and the remaining portion flows in the flow path bypassing the conduit portion 41. In this case, the amount of the cooling medium flowing through each flow path may be determined according to the temperature of the cooling medium.

  Moreover, although the above-mentioned Example demonstrated the shovel carrying the diesel engine 8, this invention is applicable also to the electric shovel carrying the electric motor as a heat source instead of a diesel engine.

  DESCRIPTION OF SYMBOLS 1 ... Lower traveling body 2 ... Upper turning body 2a, 2a1 ... Counterweight 2a2 ... Outer surface of counterweight 3 ... Cab 4 ... Boom 5 ... Arm 6 ... Bucket 7 ... Engine room 8 ... Diesel engine 9 ... Exhaust pipe 10 ... Air cleaner 11 ... Intake pipe 12 ... Cooling fan 13 ... Heat exchanger unit 14 ... Water pump 15 ... Turbocharger 16 ... Sub pump 20 ... Exhaust gas purification system 21 ... Dosing module 22 ... Urea water supply line 23 ... Urea water supply pump 24 ... Urea water tank 25 ... Urea water remaining amount sensor 26, 27 ... NOx sensor 28 ... Diesel particulate filter 29 ... Selective reduction type N Ox catalyst 30 ... excavator controller 31 ... engine control module 32 ... exhaust gas purification system controller 40, 40A, 40B ... cooling medium conduit 41, 42, 42A, 42B, 43, 43A, 43B, 44 45A, 45B ... Conduit portion 41a ... Conduit portion inlet portion 41b ... Conduit portion outlet portion 41c ... Heat sink 50 ... Switch valve 51 ... Temperature sensor

Claims (6)

A construction machine comprising a heat source, a counterweight, and a conduit for circulating a cooling medium that cools the heat source,
The conduit includes a conduit portion extending through the counterweight;
Construction machinery. The conduit portion has a heat sink;
The construction machine according to claim 1. The counterweight surface is processed to increase the surface area.
The construction machine according to claim 1 or 2. A switching valve that switches between a flow path that passes through the conduit portion and a flow path that bypasses the conduit portion;
The construction machine according to any one of claims 1 to 3.   A counterweight through which a conduit that circulates a cooling medium that cools a heat source mounted on a construction machine passes. A switching valve that switches between a heat source, a counterweight, a conduit that circulates a cooling medium that cools the heat source, a flow path that passes through the conduit portion passing through the counterweight, and a flow path that bypasses the conduit portion. A method of controlling a construction machine comprising:
A temperature detecting step for detecting a temperature of the cooling medium;
A switching valve control step for controlling the switching valve based on the temperature detected in the temperature detection step;
A method for controlling a construction machine.

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