JP2005069203A - Cooling device of industrial vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device of an industrial vehicle, cooling cooling water and hydraulic fluid with the optimum cooling efficiency and preventing the power transmission efficiency of an engine due to lowering of viscosity of hydraulic fluid of a torque converter. <P>SOLUTION: An ATC 32 obtains the upper limit rotating speed of a cooling fan 34 on the basis of the detected temperature of cooling water W of a radiator 21, temperature of hydraulic fluid Oc of cylinders 10, 11 and temperature of hydraulic fluid Ot of a torque converter 27, and regulates the rotating speed of the cooling fan 34 from rising over the upper limit rotating speed when the rotating speed of the cooling fan 34 reaches the upper limit rotating speed. In the range where the rotating speed of the cooling fan 34 is under the upper limit rotating speed, the rotating speed of the cooling fan 34 is in proportion to the rotating speed of the engine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an industrial vehicle (for example, a wheel) including a radiator that cools engine coolant, one oil cooler that cools hydraulic fluid of a hydraulic device, and another oil cooler that cools hydraulic fluid of a torque converter. Loader and the like).

  Conventionally, in a wheel loader that is an example of an industrial vehicle, a radiator for cooling engine cooling water, an oil cooler for cooling hydraulic fluid of a hydraulic device such as a cylinder, and the radiator and oil cooler are used for cooling. A cooling fan for supplying wind is provided, and the rotational output of the engine is transmitted to the cooling fan via a fan belt.

  According to this, the rotation speed of the cooling fan depends on (proportional to) only the rotation speed of the engine, regardless of the actual cooling water temperature or hydraulic oil temperature. Therefore, if the engine speed increases, the rotation speed of the cooling fan also increases in proportion to this. Therefore, the rotation speed of the cooling fan increases excessively (more than necessary), and cooling water and hydraulic oil are discharged. It is difficult to cool at an optimal cooling efficiency, and there are problems such as increased noise from the cooling fan and reduced fuel consumption of the engine.

  As countermeasures against such a problem, as shown in FIG. 10, a cooling fan 83 that sends cooling air to a radiator 81 and an oil cooler 82, a hydraulic motor 84 that drives the cooling fan 83, and a rotational speed of the hydraulic motor 84 There is an industrial vehicle 90 provided with a variable displacement hydraulic pump 85, a coolant temperature sensor 86, a hydraulic oil temperature sensor 87, an engine speed sensor 88, and a controller 89. The controller 89 determines the discharge capacity of the hydraulic pump 85 according to the temperature of the coolant and hydraulic oil detected by the temperature sensors 86 and 87 and the rotational speed of the engine 91 detected by the rotational speed sensor 88. (See, for example, Patent Document 1).

  According to this, the rotation speed of the cooling fan 83 is not dependent only on the rotation speed of the engine 91 but is controlled according to the cooling water temperature or the hydraulic oil temperature. Oil can be cooled with more optimal cooling efficiency.

  However, in the above conventional type, a torque converter is provided in an automatic transmission vehicle equipped with an automatic transmission, and in the above conventional type, the hydraulic oil of the torque converter cannot be cooled with a more optimal cooling efficiency. It was. Accordingly, there is a problem that the temperature of the hydraulic oil in the torque converter increases, the viscosity of the hydraulic oil decreases, and the power transmission efficiency of the engine 91 decreases.

If the controller 89 fails, the cooling fan 83 stops rotating, the cooling function is interrupted, and the engine 91 may be seriously damaged, such as overheating.
JP 2001-182535 A

  The present invention can cool the cooling water and the hydraulic oil with the optimum cooling efficiency, and can prevent the viscosity of the hydraulic oil of the torque converter from being lowered and the power transmission efficiency of the engine from being lowered. It is another object of the present invention to provide a cooling device for an industrial vehicle in which a cooling function by a cooling fan is sufficiently ensured even if a control device (controller) fails.

In order to achieve the above object, according to the first aspect of the present invention, a vehicle body includes a radiator that cools engine cooling water, a water temperature detector that detects a temperature of the cooling water, and one oil that cools hydraulic fluid of a hydraulic device. A cooler, one oil temperature detector for detecting the temperature of the hydraulic fluid of the hydraulic device, the other oil cooler for cooling the hydraulic fluid of the torque converter, and the other oil for detecting the temperature of the hydraulic fluid of the torque converter A temperature detector, a cooling fan for supplying cooling air to the radiator and one and the other oil coolers, and a control device are provided,
The control device obtains an upper limit rotation speed of the cooling fan based on the detected cooling water temperature, the detected hydraulic oil temperature of the hydraulic device, and the detected hydraulic oil temperature of the torque converter, and rotates the cooling fan. When the speed reaches the upper limit rotation speed, the rotation speed of the cooling fan is restricted so as not to rise above the upper limit rotation speed,
In the range where the rotational speed of the cooling fan is not more than the upper limit rotational speed, the rotational speed of the cooling fan is proportional to the rotational speed of the engine.

  According to this, if the rotation speed of the cooling fan increases in proportion to the increase in the rotation speed of the engine and the rotation speed of the cooling fan reaches the upper limit rotation speed, even if the rotation speed of the engine further increases, The rotation speed of the cooling fan does not increase beyond the upper limit rotation speed and is restricted to the upper limit rotation speed. As a result, the rotation speed of the cooling fan does not increase excessively (unnecessarily), and the cooling water and hydraulic oil can be cooled with the optimum cooling efficiency. Fuel consumption is improved.

  In addition, since the hydraulic fluid of the torque converter is also cooled with the optimum cooling efficiency, it is possible to prevent the problem that the viscosity of the hydraulic fluid in the torque converter is reduced and the transmission efficiency of the engine power is reduced.

  Further, according to the second aspect of the present invention, the control device detects the upper limit rotational speed obtained from the detected coolant temperature and the detected upper hydraulic speed of the hydraulic device and the detected torque converter operation. Among the upper limit rotational speeds determined from the oil temperature, the largest upper limit rotational speed is adopted as the official upper limit rotational speed.

The present invention also provides a hydraulic motor that rotates a cooling fan, a pump that operates with the power of the engine to supply hydraulic fluid for the motor to the hydraulic motor, and hydraulic fluid for the motor that is supplied from the pump to the hydraulic motor. A supply amount regulating valve device for regulating the supply amount of
A bypass passage that bypasses the hydraulic motor is formed in the middle of a supply passage that supplies the hydraulic fluid for the motor from the pump to the hydraulic motor.
The supply amount regulating valve device outputs to the flow control valve a flow rate control valve that adjusts the flow rate of the hydraulic fluid for the motor that bypasses the hydraulic motor and flows through the bypass flow path, and a pilot pressure for switching the flow rate control valve. It is composed of an electromagnetic pressure control valve and a pressure reducing valve that reduces the hydraulic pressure supplied to the pressure control valve.
The control device outputs a control current corresponding to the upper limit rotational speed to the pressure control valve, and the pilot pressure output from the pressure control valve to the flow rate control valve is controlled according to the control current.

  According to this, the hydraulic fluid for the motor discharged from the pump is supplied to the hydraulic motor through the supply flow path, whereby the hydraulic motor is operated and the cooling fan is rotated. At this time, the control device outputs a control current to the pressure control valve according to the obtained upper limit rotational speed, the pilot pressure output from the pressure control valve to the flow control valve is controlled, and the engine rotational speed increases. In proportion to this, the supply amount of hydraulic fluid for the motor supplied from the pump to the hydraulic motor increases, thereby increasing the rotational speed of the hydraulic motor and the rotational speed of the cooling fan proportional to the rotational speed of the engine.

  When the rotation speed of the cooling fan reaches the upper limit rotation speed due to the increase in the rotation speed of the engine, a predetermined amount of hydraulic fluid for the motor is supplied to the hydraulic motor. If the engine rotational speed further increases from this state and the discharge amount of the hydraulic fluid for the motor discharged from the pump increases above the predetermined amount, the flow control is performed by the pilot pressure output from the pressure control valve to the flow control valve. The valve is switched, and only a predetermined amount of the hydraulic fluid for the motor discharged from the pump is supplied to the hydraulic motor, and the other surplus amount flows through the bypass passage and is not supplied to the hydraulic motor. Thereby, even if the rotational speed of the engine increases, the rotational speed of the cooling fan does not increase above the upper limit rotational speed.

  Further, according to the fourth aspect of the present invention, when the control current output from the control device to the pressure control valve decreases, the upper limit rotational speed increases, and when the control current becomes 0, the upper limit rotational speed becomes the maximum upper limit rotational speed. It is set to be.

  According to this, in the unlikely event that the control device fails and the control current output from the control device to the pressure control valve becomes zero, the upper limit rotation speed becomes the maximum upper limit rotation speed. The cooling function is sufficiently guaranteed. As a result, it is possible to prevent such a problem that the upper limit rotational speed is too low and the cooling fan rotational speed is insufficient to cause overheating.

  In the fifth aspect of the invention, the control device is incorporated in an automatic transmission controller that automatically controls and switches the traveling speed stage of the transmission according to the traveling speed.

According to this, since one type of automatic transmission controller can perform two types of control, that is, shift control during driving and cooling control, the cost can be reduced.
Further, the sixth invention is provided with an input means for inputting any one of a plurality of vehicle types, and a display means for displaying the input vehicle type,
The control device incorporates a plurality of software for obtaining the upper limit rotational speed for each vehicle type, and executes software corresponding to the vehicle type input from the input means.

  According to this, since one type of control device can be commonly used for industrial vehicles of a plurality of vehicle types, cost reduction can be realized.

  As described above, according to the present invention, the rotation speed of the cooling fan can be prevented from excessively (unnecessarily) rising, and the cooling water and hydraulic oil can be cooled with the optimum cooling efficiency. Noise is reduced and engine fuel efficiency is improved.

  In addition, since the hydraulic fluid of the torque converter is also cooled with the optimum cooling efficiency, it is possible to prevent the problem that the viscosity of the hydraulic oil in the torque converter is reduced and the transmission efficiency of the engine power is reduced.

  Furthermore, even if the control device breaks down and the control current output from the control device to the supply amount regulating valve device becomes zero, the cooling function is sufficiently guaranteed, so the cooling fan rotation speed is insufficient. Thus, problems such as overheating can be prevented.

  In addition, the cost can be reduced by incorporating the control device into the automatic transmission controller, and further, the cost can be reduced by changing the control numerical value for each type of industrial vehicle from the outside.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1, 3, and 4, reference numeral 1 denotes a wheel loader that is an example of an industrial vehicle. A vehicle body 2 includes a plurality of wheels 3 that are rotationally driven by a driving force of the engine 5, and an engine 5. An automatic transmission 7 for transmitting power to each wheel 3 and a driving unit 6 are provided. In addition, a pair of left and right booms 8, a bucket 9 provided at the tip of both booms 8, and a boom hydraulic cylinder 10 (an example of a hydraulic device) that pivots both booms 8 up and down are provided at the front of the vehicle body 2. ), A bucket hydraulic cylinder 11 (an example of a hydraulic device) that swings the bucket 9 up and down, and a hydraulic device pump 13 that supplies hydraulic oil Oc to the boom hydraulic cylinder 10 and the bucket hydraulic cylinder 11; Is provided.

  The boom hydraulic cylinder 10 is moved back and forth by operating a boom operation lever (not shown) provided in the operating unit 6 in conjunction with the switching valve 15. Further, the bucket hydraulic cylinder 11 is moved back and forth by operating a bucket operation lever (not shown) provided in the operating unit 6 in conjunction with the switching valve 17.

  As shown in FIG. 3, the operating unit 6 is provided with an accelerator pedal 40, a shift lever 41 that switches forward and backward, and a key switch 42 that turns on and off the main power of the wheel loader 1. . As shown in FIG. 1, the accelerator pedal 40 is mechanically coupled to a throttle valve (not shown) of the engine 5 via a link mechanism 43 and the accelerator pedal 40 is depressed. The rotational speed of the engine 5 is increased in proportion to the amount of depression.

  The vehicle body 2 includes a radiator 21 that cools the cooling water W of the engine 5, a water temperature detector 22 that detects the temperature of the cooling water W, and one oil that cools the hydraulic oil Oc of the hydraulic cylinders 10 and 11. The cooler 24, one oil temperature detector 25 that detects the temperature of the hydraulic oil Oc of the hydraulic cylinders 10 and 11, and the other oil that cools the hydraulic oil Ot of the torque converter 27 built in the automatic transmission 7. The cooler 28, the torque converter pump 33 for circulating the hydraulic oil Ot between the torque converter 27 and the other oil cooler 28, and the other oil temperature detector 29 for detecting the temperature of the hydraulic oil Ot of the torque converter 27. And a cooling fan for supplying cooling air to the radiator 21 and the one and other oil coolers 24 and 28. 34, a hydraulic motor 35 that rotates the cooling fan 34, a cooling pump 37 that supplies motor hydraulic oil Om to the hydraulic motor 35, and a motor operation that is supplied from the cooling pump 37 to the hydraulic motor 35. A supply amount regulating valve device 38 that regulates the supply amount of the oil Om and an automatic transmission controller 32 (hereinafter referred to as ATC) are provided.

  As shown in FIG. 1, the cooling pump 37 is driven by the power of the engine 5, and the rotational speed of the cooling pump 37 is proportional to the rotational speed of the engine 5. As shown in FIGS. 1 and 2, the motor hydraulic oil Om discharged from the cooling pump 37 is supplied to the hydraulic motor 35 through the supply passage 45 and then discharged from the hydraulic motor 35. The oil tank 47 is configured to be recovered through the return channel 46. Further, a bypass flow path 48 that bypasses the hydraulic motor 35 is formed in the middle of the supply flow path 45, whereby a part of the motor hydraulic oil Om that flows through the supply flow path 45 is part of the hydraulic motor 35. Is bypassed to the return flow path 46 through the bypass flow path 48.

  The supply amount regulating valve device 38 controls the flow rate of a flow rate control valve 50 that adjusts the flow rate of the hydraulic fluid Om for the motor that flows through the bypass flow path 48, and the pilot pressure for switching the flow rate control valve 50 in the opening direction A. A pressure control valve 51 that outputs to the valve 50 and a pressure reducing valve 52 that adjusts the original pilot pressure output from the pressure control valve 51 to the flow control valve 50 to a constant value suitable for pilot control. Yes. The pressure control valve 51 is a proportional solenoid valve (electric pressure control valve), and regulates the original pressure of the pressure reducing valve 52 as a pilot pressure and outputs it to the flow rate control valve 50.

Further, pilot pipes 53 and 54 for switching the flow rate control valve 50 are provided in the middle of the supply flow path 45 to detect a pressure difference before and after the orifice 55.
Next, the control function of the ATC 32 will be described.

  The ATC 32 automatically switches the traveling speed stage of the automatic transmission 7 from the first speed to the fourth speed according to the traveling speed of the wheel loader 1, and further moves the automatic transmission 7 forward and backward according to the operation of the shift lever 41. The traveling speed stage control to be switched is performed. In other words, the ATC 32 switches the automatic transmission 7 to the first speed when excavating or climbing, switches to the second speed at the start, automatically shifts up to the third speed and the fourth speed when the traveling speed increases, and sequentially decreases to the fourth speed when decelerating. Shift down automatically from speed.

Further, the ATC 32 incorporates a control device 32a having the following cooling fan control function.
That is, the control device 32a obtains the upper limit rotational speed X of the cooling fan 34 and the control current Y corresponding to the upper limit rotational speed X in the following procedures (1) to (4).
(1) The temperature of the cooling water W detected by the water temperature detector 22 is converted into an A / D conversion value Z1, and the first upper limit rotation speed X1 of the cooling fan 34 and the rotation speed X1 based on the conversion value Z1. And a first control current Y1 corresponding to.
(2) The temperature of the hydraulic oil Oc detected by one of the oil temperature detectors 25 is converted into an A / D conversion value Z2, and the second upper limit rotational speed X2 of the cooling fan 34 and this are converted based on this conversion value Z2. A second control current Y2 corresponding to the rotational speed X2 is obtained.
(3) The temperature of the hydraulic oil Ot detected by the other oil temperature detector 29 is converted to an A / D conversion value Z3, and the third upper limit rotational speed X3 of the cooling fan 34 and the A third control current Y3 corresponding to the rotational speed X3 is obtained.
(4) Among the first to third upper limit rotational speeds X1 to X3 obtained by the above (1) to (3), the largest upper limit rotational speed is adopted as the formal upper limit rotational speed X, and the upper limit A control current Y corresponding to the rotational speed X is obtained.

  As shown in the graph of FIG. 5, the temperatures of the cooling water W and the hydraulic oils Oc and Ot detected by the detectors 22, 25 and 29, and the first to third control currents Y1 to Y1. Y3 is in an inversely proportional relationship. At this time, the first to third control currents Y1 to Y3 are calculated by the following equations, respectively.

Y1 = A1 · Ln (X1) −B1
Y2 = A2 · Ln (X2) −B2
Y3 = A3 · Ln (X3) −B3
Note that A1 to A3 and B1 to B3 are constants.

  For reference, Table 1 below shows values of the upper limit rotational speeds X1 to X3 with respect to the respective temperatures of the cooling water W of the radiator 21, the hydraulic oil Ot of the torque converter 27, and the hydraulic oil Oc of the hydraulic cylinders 10 and 11. In addition, the value of the upper limit rotational speed between each temperature has a proportional relationship.

そして、上記制御装置３２ａは、図２に示すように、上記手順（４）で求められた上限回転速度Ｘに対応する制御電流Ｙを圧力制御弁５１へ出力し、この制御電流Ｙの値に比例したパイロット圧Ｐａが圧力制御弁５１から流量制御弁５０へ出力される。

Then, as shown in FIG. 2, the control device 32a outputs a control current Y corresponding to the upper limit rotational speed X obtained in the procedure (4) to the pressure control valve 51, and sets the control current Y to the value of the control current Y. A proportional pilot pressure Pa is output from the pressure control valve 51 to the flow control valve 50.

Hereinafter, the cooling control in the above configuration will be described.
As shown in FIG. 1, the cooling pump 37 is rotationally driven by the engine 5, and the motor hydraulic oil Om discharged from the cooling pump 37 is supplied to the hydraulic motor 35 through the supply passage 45, and then the return is performed. It is collected in the oil tank 47 through the flow path 46. As a result, the hydraulic motor 35 operates to rotate the cooling fan 34, and cooling air is supplied from the cooling fan 34 to the radiator 21 and one and the other oil coolers 24 and 28.

  The graph of FIG. 6 shows the rotational speed of the engine 5 (= corresponding to the discharge amount of the motor hydraulic oil Om discharged from the cooling pump 37) and the rotational speed of the hydraulic motor 35 (= for the motor supplied to the hydraulic motor 35). (Corresponding to the supply amount of hydraulic oil Om).

  According to this, when the driver depresses the accelerator pedal 40 and increases the rotational speed of the engine 5 from the minimum rotational speed Lo during idling, the discharge amount of the cooling pump 37 increases in proportion to the rotational speed of the engine 5. As a result, the supply amount of the hydraulic fluid Om supplied to the hydraulic motor 35 increases. As a result, the rotational speed of the hydraulic motor 35 increases in proportion to the rotational speed of the engine 5.

  At this time, as shown in FIG. 2, the pilot pressure Pa output from the pressure control valve 51 and the differential pressure Pb between the inlet side (upstream side) and the outlet side (downstream side) of the orifice 55 cause the flow control valve 50 to flow. It acts as a pilot pressure (= pilot pressure Pa + differential pressure Pb) for switching to the opening direction A. The differential pressure Pb is the difference between the pilot pressure supplied from one pilot line 53 to the flow control valve 50 and the pilot pressure supplied from the other pilot line 54 to the flow control valve 50 (= one of the pilot pressures). The pilot pressure from the pilot line 53 minus the pilot pressure from the other pilot line 54).

  In proportion to the increase in the rotational speed of the engine 5, the discharge amount of the cooling pump 37 increases and the differential pressure Pb increases. When the rotational speed of the engine 5 reaches the predetermined rotational speed Re and the value obtained by adding the pilot pressure Pa and the differential pressure Pb becomes the predetermined pressure P (Pa + Pb = P), the flow control valve 50 is opened in the opening direction. Switch to. As a result, a part of the motor hydraulic oil Om flowing through the supply flow path 45 bypasses the return flow path 46 through the bypass flow path 48, so that the differential pressure Pb between the inlet side and the outlet side of the orifice 55 is a predetermined pressure. The pressure does not increase beyond a predetermined value (= P−Pa) obtained by subtracting the pilot pressure Pa from P, and the upper limit of the differential pressure Pb is regulated to the predetermined value (= P−Pa). As a result, as shown in FIG. 6, when the rotational speed of the engine 5 is in the range from the predetermined rotational speed Re to the maximum rotational speed Hi, the differential pressure Pb between the inlet side and the outlet side of the orifice 55 is the predetermined value ( = P−Pa), only a predetermined amount of the motor hydraulic oil Om discharged from the cooling pump 37 is supplied to the hydraulic motor 35, and the other surplus amount passes through the bypass passage 48. Bypass to return channel 46. As a result, the rotational speed of the hydraulic motor 35 is regulated to a predetermined rotational speed Rm, and the predetermined rotational speed Rm corresponds to the upper limit rotational speed X of the cooling fan 34.

  For example, when the temperature of the cooling water W and the temperature of the hydraulic oil Oc, Ot detected by the detectors 22, 25, 29 are increased, the value of the control current Y is decreased in inverse proportion to the pressure control valve 51. The pilot pressure Pa output from the engine to the flow control valve 50 also decreases. As a result, the predetermined value (= P−Pa) increases, so that the differential pressure Pb between the inlet side and the outlet side of the orifice 55 increases, and accordingly, as shown in FIG. The rotational speed Re increases. As a result, a larger amount of motor hydraulic oil Om can be supplied to the hydraulic motor 35 until the predetermined pressure P is reached. As a result, the predetermined rotational speed Rm of the hydraulic motor 35, that is, the upper limit rotational speed X of the cooling fan 34 increases. To do.

  On the contrary, when the temperature of the cooling water W detected by each detector 22, 25, 29 and the temperature of the hydraulic oil Oc, Ot are decreased, the value of the control current Y is increased in inverse proportion to the pressure control valve. The pilot pressure Pa output from 51 to the flow control valve 50 also increases. As a result, the predetermined value (= P−Pa) is reduced, so that the differential pressure Pb between the inlet side and the outlet side of the orifice 55 is reduced. Accordingly, as shown in FIG. Rotational speed Re is reduced. As a result, the amount of motor hydraulic oil Om that can be supplied to the hydraulic motor 35 until the predetermined pressure P is reached decreases. As a result, the predetermined rotational speed Rm of the hydraulic motor 35, that is, the upper limit rotational speed X of the cooling fan 34 is increased. descend.

  As described above, when the rotational speed of the cooling fan 34 reaches the upper limit rotational speed X, the rotational speed of the cooling fan 34 exceeds the upper limit rotational speed X even if the rotational speed of the engine 5 further increases. The upper limit rotational speed X is not increased. As a result, the rotation speed of the cooling fan 34 does not increase excessively (more than necessary), and the cooling water W and the hydraulic oil Oc, Ot can be cooled with optimal cooling efficiency. The fuel consumption of the engine 5 is improved.

  In addition, since the hydraulic oil Ot of the torque converter 27 is also cooled with the optimum cooling efficiency, it is possible to prevent a problem such that the viscosity of the hydraulic oil Ot in the torque converter 27 is reduced and the power transmission efficiency of the engine 5 is reduced. Can do.

  In addition, as shown in FIG. 7, the upper limit rotational speed X of the cooling fan 34 is stepless in accordance with the temperature of the cooling water W and the temperature of the hydraulic oil Oc, Ot detected by the detectors 22, 25, 29. Therefore, the cooling water W and the hydraulic oils Oc and Ot can be cooled with a further optimal cooling efficiency according to the situation.

  If the control device 32a fails and the control current Y output from the control device 32a to the pressure control valve 51 becomes 0, the pilot pressure output from the pressure control valve 51 to the flow control valve 50 Pa becomes zero. As a result, when the differential pressure Pb between the inlet side and the outlet side of the orifice 55 reaches the predetermined pressure P (Pb = P), the flow control valve 50 is switched to the opening direction A. In this case, the amount of motor hydraulic oil Om that can be supplied from the supply flow path 45 to the hydraulic motor 35 is maximized, and as a result, as shown by a point A in FIG. The upper limit rotational speed X of the fan 34 becomes the maximum upper limit rotational speed Xmax. As a result, the rotation speed of the cooling fan 34 is not insufficient, and the cooling function is sufficiently ensured, so that the upper limit rotation speed X is too low and the rotation speed of the cooling fan 34 is insufficient to cause overheating. Can be fail safe.

  Furthermore, since the control device 32a having the cooling fan control function as described above is incorporated in the ATC 32, two types of control, that is, shift control during driving and cooling control, can be performed by one ATC 32, thereby reducing costs. I can plan.

Next, a second embodiment will be described with reference to FIGS.
In addition to the wheel loader 1, the industrial vehicle includes, for example, as shown in FIG. 8, a vessel dump 61 that transports shears, a slag dump 62 that transports slag and the like of a steel mill, a forklift 63 that transports containers, and the like. Exists. A unique model number is set for each of the wheel loader 1, the vessel dump 61, the slag dump 62, and the forklift 63. Further, the numerical values such as the inclination of the graph shown in FIG. 7, the upper limit rotational speed X, the control current Y, the predetermined pressure P, etc. are respectively for the plurality of vehicle types (wheel loader 1, vessel dump 61, slag dump 62, forklift 63). Are different.

  As shown in FIG. 9, the ATC 32 displays a switch 65 (an example of input means) for inputting a model number of any one of the plurality of vehicle types, and the model number of the input vehicle type. A liquid crystal display unit 66 (an example of display means) is provided.

  Further, the ATC 32 includes a plurality of software 68 to 71 for obtaining the upper limit rotational speed X for each vehicle type, and software corresponding to the model number of the vehicle type input by the switch 65 (that is, the first to fourth software 68 to 71). And a selection unit 72 having a function of selecting and executing any one of them.

  According to this, when the vehicle type of the industrial vehicle is the wheel loader 1, the operator operates the switch 65 to input the model number of the wheel loader 1. As a result, the model number of the wheel loader 1 is displayed on the liquid crystal display unit 66, the first software 68 corresponding to the wheel loader 1 is selected and executed, and the cooling fan 34 is controlled by the control device 32a built in the ATC 32. Is done.

  Further, in the case of the vessel dump 61, by operating the switch 65 and inputting the model number of the vessel dump 61, the model number of the vessel dump 61 is displayed on the liquid crystal display unit 66, and the second number corresponding to the vessel dump 61 is displayed. The software 69 is selected and executed, and the cooling fan 34 is controlled by the control device 32 a built in the ATC 32. Similarly, in the case of the slag dump 62, by inputting the model number of the slag dump 62, the third software 70 corresponding to the slag dump 62 is selected and executed. In the case of the forklift 63, the model number of the forklift 63 is input. Thus, the fourth software 71 corresponding to the forklift 63 is selected and executed. Thereby, since one type of ATC 32 can be used in common for industrial vehicles of a plurality of vehicle types, further cost reduction can be realized.

  In the first embodiment, as shown in FIG. 1, the other oil cooler 28 is built in the radiator 21. However, the other oil cooler 28 may be individually installed outside the radiator 21.

In the first embodiment, the hydraulic cylinders 10 and 11 are given as an example of the hydraulic device, but other hydraulically driven cargo handling devices may be used.
In the first embodiment, the first upper limit rotational speed X1 obtained from the detected temperature of the cooling water W, and the second upper limit rotational speed X2 obtained from the detected temperature of the hydraulic oil Oc. Among the third upper limit rotation speeds X3 obtained from the detected temperature of the hydraulic oil Ot, the largest upper limit rotation speed is adopted as the official upper limit rotation speed X. You may employ | adopt as the formal upper limit rotational speed X the upper limit rotational speed calculated | required from the highest temperature among the temperature of water W and the temperature of hydraulic oil Oc, Ot.

  In the said 2nd Embodiment, although the wheel loader 1, the vessel dump 61, the slag dump 62, and the forklift 63 were mentioned as an example of an industrial vehicle, vehicles of other types may be sufficient.

It is a circuit diagram of the cooling device of the industrial vehicle in the 1st Embodiment of this invention. It is a block diagram of the supply amount control valve apparatus of the cooling device of an industrial vehicle. It is a side view of the wheel loader cited as an industrial vehicle. It is a schematic plan view of a wheel loader cited as an industrial vehicle. It is a graph which shows the relationship between the temperature of the cooling water and hydraulic oil of an industrial vehicle, and control current. It is a graph which shows the relationship between the rotational speed of the engine of an industrial vehicle, and the rotational speed of a hydraulic motor. FIG. 6 is a graph showing the relationship between the rotational speed of an engine of an industrial vehicle and the rotational speed of a hydraulic motor, with the upper limit rotational speed set steplessly according to the detected temperature added. It is a side view of the industrial vehicle in the 2nd Embodiment of this invention, (a) is a vessel dump, (b) is a slag dump, (c) shows a forklift. It is a block diagram which shows the structure of ATC of an industrial vehicle. It is a circuit diagram of the cooling device of the conventional industrial vehicle.

Explanation of symbols

1 Wheel loader (industrial vehicle)
2 Car body 5 Engine 7 Automatic transmission 10, 11 Hydraulic cylinder (hydraulic device)
21 Radiator 22 Water temperature detector 24 One oil cooler 25 One oil temperature detector 27 Torque converter 28 Other oil cooler 29 Other oil temperature detector 32 ATC
32a Control device 34 Cooling fan 35 Hydraulic motor 37 Cooling pump 38 Supply amount regulating valve device 45 Supply flow path 48 Bypass flow path 50 Flow control valve 51 Pressure control valve 61 Vessel dump (industrial vehicle)
62 Slag dump (industrial vehicle)
63 Forklift (Industrial Vehicle)
65 switch (input means)
66 Liquid crystal display (display means)
68-71 Software Oc Hydraulic cylinder hydraulic fluid Ot Torque converter hydraulic fluid Om Motor hydraulic fluid Pa Pilot pressure W Cooling water X Upper limit rotation speed Xmax Maximum upper limit rotation speed Y Control current

Claims (6)

A radiator for cooling the engine coolant, a water temperature detector for detecting the coolant temperature, one oil cooler for cooling the hydraulic fluid, and a temperature of the hydraulic fluid for the hydraulic device are detected on the vehicle body. One oil temperature detector, the other oil cooler that cools the hydraulic oil of the torque converter, the other oil temperature detector that detects the temperature of the hydraulic oil of the torque converter, the radiator, and the one and the other oil coolers And a cooling fan for supplying cooling air to the control unit and a control device,
The control device obtains an upper limit rotation speed of the cooling fan based on the detected cooling water temperature, the detected hydraulic oil temperature of the hydraulic device, and the detected hydraulic oil temperature of the torque converter, and rotates the cooling fan. When the speed reaches the upper limit rotation speed, the rotation speed of the cooling fan is restricted so as not to rise above the upper limit rotation speed,
The industrial vehicle cooling device characterized in that the rotational speed of the cooling fan is proportional to the rotational speed of the engine when the rotational speed of the cooling fan is equal to or less than the upper limit rotational speed. The control device determines the upper limit rotational speed obtained from the detected upper limit rotational speed obtained from the detected coolant temperature, the detected upper limit rotational speed from the hydraulic fluid temperature of the hydraulic system, and the detected hydraulic oil temperature of the torque converter. 2. The industrial vehicle cooling apparatus according to claim 1, wherein the upper limit rotational speed having the largest value among the speeds is adopted as the official upper limit rotational speed. A hydraulic motor that rotates the cooling fan, a pump that operates with the power of the engine to supply the hydraulic fluid to the hydraulic motor, and a supply amount that regulates the supply amount of the hydraulic fluid supplied from the pump to the hydraulic motor A restriction valve device,
A bypass passage that bypasses the hydraulic motor is formed in the middle of a supply passage that supplies the hydraulic fluid for the motor from the pump to the hydraulic motor.
The supply amount regulating valve device outputs to the flow control valve a flow rate control valve that adjusts the flow rate of the hydraulic fluid for the motor that bypasses the hydraulic motor and flows through the bypass flow path, and a pilot pressure for switching the flow rate control valve. It is composed of an electromagnetic pressure control valve and a pressure reducing valve that reduces the hydraulic pressure supplied to the pressure control valve.
The control device outputs a control current corresponding to the upper limit rotation speed to the pressure control valve, and the pilot pressure output from the pressure control valve to the flow rate control valve is controlled according to the control current. The cooling device for an industrial vehicle according to claim 1 or 2. The upper limit rotational speed increases as the control current output from the control device to the pressure control valve decreases. When the control current becomes 0, the upper limit rotational speed is set to the maximum upper limit rotational speed. The industrial vehicle cooling device according to claim 3. 5. The industrial use according to claim 1, wherein the control device is incorporated in an automatic transmission controller that automatically controls and switches a traveling speed stage of the transmission according to the traveling speed. 6. Vehicle cooling device. Input means for inputting any one of a plurality of vehicle types, and display means for displaying the input vehicle type are provided.
6. The control device according to claim 1, wherein the control device includes a plurality of software for obtaining an upper limit rotational speed for each vehicle type, and executes software corresponding to the vehicle type input from the input unit. The cooling device for industrial vehicles described in 1.

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