JP2003020944A - Construction machine with temperature sensitive type cooling fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan from rotating during warm up operation by using a temperature sensitive type cooling fan. SOLUTION: The construction machine is equipped with a warming up operation device 31 that increases rotational speed engine higher than that of normal operation when the temperature of the operation oil or engine cooling water is lower than the predetermined upper limit temperature of warming up operation, and the engine cooling fan device 10 driven by the engine 1 the fan is not operated when the atmospheric temperature is below a predetermined fan retainer start temperature controlled by the action of temperature sensitive clutch CR and is operated when the temperature is not lower than fan rotation start temperature. After starting the warm up operation, the fan rotation start temperature is so set that the atmospheric temperature reaches the start temperature after the operation oil temperature attains not lower than the upper limit temperature of warming up operation.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction machine having a temperature-responsive cooling fan that rotates according to the ambient temperature. 2. Description of the Related Art In a construction machine such as a hydraulic excavator, when the operating oil temperature or the engine cooling water temperature is lower than a predetermined warm-up operation upper limit temperature, such as immediately after the start of the engine, the engine speed is set lower than usual. The warm-up operation is performed at a higher temperature, and control is performed to return the engine speed to the normal speed when the oil temperature (cooling water temperature) reaches the warm-up operation upper limit temperature. [0003] By the way, during the warm-up operation immediately after the start of the engine, it is not necessary to cool the engine, and it is desirable to stop the engine cooling fan. However, since the conventional cooling fan is directly connected to the engine and is always driven when the engine is driven, the fan also rotates during the warm-up operation and becomes supercooled, so that it takes time for the warm-up operation There is a problem. An object of the present invention is to provide a construction machine using a temperature-responsive cooling fan so that the fan does not rotate during a warm-up operation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a construction machine having a temperature-sensitive engine cooling fan according to the present invention; A warm-up device 31 for performing a warm-up operation in which the engine speed is increased from the normal operation when the temperature is lower than the operation upper limit temperature. An engine cooling fan device 10 that does not operate at a temperature lower than the temperature but operates when the temperature is equal to or higher than the fan rotation start temperature. Set the fan rotation start temperature so that the ambient temperature reaches the fan rotation start temperature,
This solves the above problem. In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. However, the present invention is not limited to this. An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram showing a main part of a construction machine according to the present embodiment. Reference numeral 3 denotes a hydraulic pump driven by the engine 1, and reference numeral 100 denotes an engine cooling fan device also driven by the engine 1. The drive of the hydraulic pump 3 drives the front of the hydraulic work, travels and turns the vehicle, and the like. Also, the cooling fan device 100
Is composed of a blower fan FN and a fluid coupling (corresponding to a temperature-sensitive clutch) CR for controlling driving / stopping and rotation speed of the fan FN. Although the details of the fluid coupling CR will be described later, the rotation of the fan FN cools the engine cooling water in the radiator 2, thereby contributing to the cooling of the engine 1. [0008] The rotation speed of the engine 1 is controlled by a controller 31. That is, the controller 31 reads the operation status of the engine speed setting dial 32, and sets the motor 3 to rotate the engine 1 at a speed corresponding to the operation.
3 controls the engine speed setting device 1a. An oil temperature sensor 34 for detecting the temperature of the hydraulic oil is connected to the controller 31. When the hydraulic oil temperature is lower than a predetermined warm-up operation upper limit temperature tw, for example, immediately after the start of the engine, the engine rotation as shown in FIG. The warm-up operation is performed while maintaining the number at a rotation speed Nw higher than the normal rotation speed Nn. Then, when the temperature detected by the oil temperature sensor 34 reaches the warm-up operation upper limit temperature tw, the warm-up operation is terminated, and the normal engine speed Nn is returned. FIG. 2 is a view showing a fluid coupling CR of the cooling fan device 10. A drive disk 12 is integrally attached to a shaft 11 that is driven to rotate by the engine 1.
4 are inserted into a torque transmission chamber 15 defined by the torque transmission chamber 4. A fan FN (FIG. 1) is attached to the case 13 and the cover 14, and the shaft 11 is rotatably supported by the case 13 via a bearing 16. The torque transmission chamber 15 communicates with an oil storage chamber 18 via a port 17. The oil storage chamber 18 is filled with silicone oil, and the amount of oil supplied from the storage chamber 18 to the torque transmission chamber 15 changes by adjusting the opening of the port 17 by the valve plate 19. A linear weight 20 is attached to the valve plate 19, and the operation of the linear weight 20 causes the fan speed to change linearly as described later. The bimetal 21 held on the cover 14 drives the valve plate 19 via the piston 22 in response to the ambient temperature after passing through the radiator. When the ambient temperature after passing through the radiator is low, such as immediately after starting the engine, the valve plate 19 blocks the port 17, and the silicon oil in the storage chamber 18 is not guided to the torque transmission chamber 15. Engine 1
Rotation of the shaft 11 and the drive disk 12
Of the fan FN
And the fan FN does not rotate. When the ambient temperature rises after passing through the radiator, the piston 22 is driven by the action of the bimetal 21, and the valve plate 1
9 opens port 17. Storage room 1 by opening the port
The silicone oil No. 8 is guided to the torque transmission chamber 15 through the port 17, and the rotation of the drive disk 12 is transmitted to the fan FN by the generation of the transmission torque, and the fan FN rotates. Here, the opening degree of the port 17 increases as the ambient temperature increases, and as the opening degree of the port 17 increases, the amount of oil guided to the torque transmission chamber 15 increases, and as the amount of oil increases, the rotation speed of the fan FN increases. Is faster. In this embodiment, as shown in FIG. 4, when the ambient temperature after passing through the radiator is lower than the fan rotation lower limit temperature (corresponding to the fan rotation start temperature) tf1, the fan rotation speed becomes zero.
The fan rotation speed linearly increases from tf1 until the fan rotation upper limit temperature tf2 is reached, and is set so that the fan rotation speed becomes a constant value (Max) above tf2. Also, hunting of the fan speed is prevented by providing hysteresis as shown. Here, the temperatures tf1 and tf2 depend on the viscosity of the silicone oil and the piston 2
The stroke can be adjusted as appropriate by changing the stroke of No. 2, the weight of the linear weight 20, and the like. During the warm-up operation, the fan F
When N rotates, the engine 1 becomes supercooled, and the time required for the warm-up operation becomes longer. Therefore, in this embodiment,
As shown in FIG. 5, the operating oil temperature is equal to the warm-up operation upper limit temperature t.
tf1 is adjusted so that the ambient temperature reaches the fan rotation lower limit temperature tf1 at a time T2 after the time T1 exceeding w. Here, it may be considered that the temperature of the atmosphere after passing through the radiator changes while maintaining a temperature slightly higher than the temperature of the hydraulic oil until a certain time elapses from the start of the engine, so that tf1 is a temperature slightly higher than tw. Should be set to. For example, when tw is set to about 30 degrees, tf1 may be set to about 50 degrees. According to this, since the fan FN does not rotate during the warm-up operation, the efficiency of the warm-up operation can be improved, and the time required for the warm-up operation can be reduced. After the ambient temperature reaches tf2 at time T2, the fan speed is kept at a constant value Max. This tf2 is set according to the heat balance of the vehicle body.
A temperature that satisfies the required heat radiation, that is, a temperature that can prevent problems such as overheating (for example, 80 to 90 degrees).
Is set to In the above description, a linear type fan device is used in which the fan rotation speed linearly increases and decreases according to the ambient temperature after the fan rotation lower limit temperature is reached. Does not operate, and may be an on / off type fan device that rotates at a constant speed when the temperature exceeds the fan rotation start temperature. Also in this case, the same operation and effect as described above can be obtained by setting the ambient temperature to reach the fan rotation start temperature after the operating oil temperature becomes equal to or higher than the warm-up operation upper limit temperature tw. Although the operating oil temperature is used as a parameter for determining whether or not the warm-up operation is necessary, the operating oil temperature may be replaced with the engine cooling water temperature. Further, the temperature-sensitive clutch is not limited to a fluid coupling. According to the present invention, after starting the warm-up operation, the ambient temperature reaches the fan rotation lower-limit temperature after the operating oil temperature or the engine cooling water temperature becomes higher than the warm-up operation upper limit temperature. Therefore, the efficiency of the warm-up operation can be improved without driving the fan during the warm-up operation, and the time required for the warm-up operation can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a main configuration of a construction machine according to an embodiment of the present invention. FIG. 2 is a sectional view showing a configuration of a fluid coupling portion of the fan device. FIG. 3 is a diagram illustrating warm-up operation control. FIG. 4 is a diagram illustrating rotation characteristics of a fan device. FIG. 5 is a diagram showing a temporal relationship between a warm-up operation and a fan speed. [Description of Signs] 1 engine 2 radiator 3 hydraulic pump 10 engine cooling fan device 31 controller 34 oil temperature sensor FN fan CR fluid coupling

Claims (1)

Claims: 1. A warm-up device for performing a warm-up operation for increasing an engine speed more than usual when a hydraulic oil temperature or an engine cooling water temperature is lower than a predetermined warm-up operation upper limit temperature; An engine cooling fan device that is driven by the engine and does not operate when the ambient temperature is lower than a predetermined fan rotation start temperature due to the action of the temperature-sensitive clutch but operates when the ambient temperature is equal to or higher than the fan rotation start temperature; After that, the fan rotation start temperature is set so that the ambient temperature reaches the fan rotation start temperature after the operating oil temperature or the engine cooling water temperature becomes equal to or higher than the warm-up operation upper limit temperature. Construction machinery having a mold cooling fan.