JPS5813119A - Automatic control device for cooling fan - Google Patents

Abstract

PURPOSE:To control the amount of wind which is emitted by a cooling fan driven by an hydraulic motor, by controlling the discharge amount of a variable capacity pump with a control circuit which emits a control signal in compliance with the difference between the output from the water temperature sensor installed at the inlet of radiator and the reference value. CONSTITUTION:The difference epsilon between the output Vt from a cooling water temp. sensor 15 insetalled at the inlet of the radiator 1 and the reference temperature signal Vt is amplified by an amplifier with a gain of -K1 to be fed into a servo valve drive circuit 14 with a gain of K2 through a contact 13b. This servo valve drive circuit 14 controls the servo valve 23 of a variable capacity hydraulic pump 22 to put its discharge amount under control, so that the number of revolutions of an hydraulic motor 21 for drive of the cooling fan 2 is controlled in compliance with the cooling water temperature which is now maintained at a certain intended value. The contact 13B is used, while the retarder brake is in application, to feed the maximum revolutions command signal Vm to the servo valve drive circuit 14. Thus the cooling fan 2 rotates at its maximum speed.

Description

[Detailed description of the invention]

The present invention provides engine cooling fan self-excitation control 181! Regarding the location. In order to efficiently operate the engine in the damp footer, etc., it is necessary to maintain the cooling water temperature at an appropriate temperature. Therefore, while the cooling water is circulated through the path of radiator → engine → radiator, a cooling fan is connected to the output shaft of the engine via a fan belt, and this fan is rotated to blow air from the radiator to cool the cooling water. I have to. However, in the conventional cooling device that rotates a fan via a fan belt, the engine rotational speed *
Since the fan rotates according to the cooling water temperature, it is possible to control the air flow to the radiator depending on the cooling water temperature, but the cooling water temperature cannot be maintained at an appropriate value, so the engine may not operate efficiently. It had the disadvantages of large scratches and horsepower loss. The present invention was made for the purpose of eliminating the above-mentioned drawbacks of the conventional technology.The cooling fan is driven by a hydraulic motor, and the air volume is controlled according to the cooling water temperature to maintain the cooling water temperature near the optimum value for engine efficiency. The present invention provides a cooling fan self-control device. Hereinafter, the present invention will be described in detail with reference to one embodiment of the accompanying drawings. In Figure 1, engine cooling water circulates through the path of radiator 1 → engine 3 → brake oil gura 4 → 2 radiator 1, and the hydraulic oil during retarder play goes from oil tank 5 → left and right retarder brakes. 6. 7 → Brake oil cooler 4 → Oil tank 151) It is designed to circulate through the flow. After cooling the engine 3, the cooling water cooled in 5 j! Then, the retarder brake hydraulic oil is cooled in the brake oil goo 94. The cooling water i whose water temperature has increased during the overvibration to cool the engine 3 and the brake hydraulic oil is cooled again in the radiator 1. On the other hand, cooling fan 2 shirt) 2atilKI61B2
It is connected to the hydraulic motor fi21 of G, and the WA@ is driven by this hydraulic motor j121. This hydraulic motor 21 is rotationally driven by oil discharged from a hydraulic pump 22 with a variable valley volume. The variable capacity -1:'1 pressure pump 22 is, for example, a swash plate type hydraulic pump, and the swash plate angle is controlled by a servo valve 23.
The trap is configured so that the discharge capacity is controlled accordingly. The hydraulic pump 22 is driven by the engine 3, and the load on the engine 3 changes depending on the discharge amount of the hydraulic pump 22. The rotational speed of the hydraulic motor 21 changes depending on the discharge amount of the hydraulic pump 22. The cooling fan 2 rotates in accordance with the rotation of the hydraulic motor and blows air to the radiator 1 to cool the radiator/1t. The water temperature sensor t15 is arranged at a predetermined position in the vicinity of 1 m of cooling water of the radiator 1, and detects the temperature of the cooling water flowing into the radiator 1, outputs a temperature signal Vc for comparison, and sends it to the control circuit 1O. . This water temperature center t1G is composed of, for example, a water temperature center. lIJ#Circuit 100 Reference Temperature Setting a]1 is for setting the reference cooling water temperature, and a temperature signal V! corresponding to the preset water temperature is provided. Output. This standard temperature! is set to a value that optimizes engine efficiency. Reference voltage signal v1 and actual cooling water temperature Vt
The difference C between
is output as Amplification 1) The gain of 12 is -X, so

[, the polarity of the output signal V# is opposite to the polarity of the input signal C. This deviation signal V# is applied to contact 131hK of retarder switch ]3. Also, retarder switch 1
A maximum rotation command signal V is applied to contact point 13 of No. 3. This command signal Vm is used to set the rotational speed of the cooling fan 2 to the maximum rotation speed tK when the retarder brake is used. The retarder switch 13 is interlocked with, for example, a retarder brake lever (not shown), and when the retarder brake is used, the switch is turned on, the contact 13M is turned on, and the contact 13B is turned off. During normal driving without using the retarder brake, the KFi switch is turned off and contact 1
3 is off and contact 13B is on. Then, the retarder switch 13 sends the command signal Vm or the deviation signal TI to S.
*Output and add to Nervo valve H# circuit 14. When the human input signal has the polarity of the t-point valve movement circuit 14,
A control signal Vs corresponding to the magnitude of the human power signal is output. Further, in the case of one-manpower signal fi□ polarity, no control signal is output (Vl-0). Servo valve 23 Hiroto car 11 (No. 1 V
- to control the swash plate angle of the hydraulic pump 22. The swash plate angle of this hydraulic pump 22 becomes the minimum when the control signal V- is O, and the discharge amount accordingly becomes the minimum. The discharge amount of this sharpening is a very small amount of S degree that does not cause seizure of the hydraulic pump 22 itself. Now, first, let us consider the case when the retarder switch 13 is off, that is, during normal operation. When the cooling water □ temperature is lower than the reference water temperature, # has Vt (IFt
Therefore, the deviation becomes #Ofi, and the output signal of the amplifier 12 becomes -v1. Therefore, the control signal v1 becomes O, and the discharge amount of the hydraulic pump 22 becomes minimum. Therefore,
The speed of the hydraulic motor 21 becomes the lowest, and the cooling fan 2
The same rotation speed is also low. Further, the negative effect caused by cooling the engine 3 by 7 amps is also minimized. In this state] 11, the amount of air blown to the air 7'l is almost zero. If the cooling water temperature is lower than the standard water temperature, it is necessary to blow air to Radiator/1*a
do not have. When the temperature of the engine 3 rises and the cooling water temperature rises accordingly and becomes Vt), the deviation #(1vt-vt)
The polarity of is θ, and the deviation signal V# is of OII nature. The JII 6-path 14 outputs a control signal corresponding to Va in the human input signal and applies it to the nervo valve 2BK. The nap valve 2s controls the swash plate angle of the hydraulic pump 2 in response to this control signal, thereby controlling the discharge amount. The cold #7 fan 2 is rotated at a rotational speed according to the discharge amount of the m-pressure motor j121 and the hydraulic pump 22 to blow air to the radiator l to cool the radiator l. Then, the cooling water temperature flowing through the radiator IK is controlled to the reference water temperature pipe. In this way, the temperature of the cooling water flowing in the path of radiator jll → engine 3 → oil roller 4 → radiator l is set to the reference water temperature? Hold the engine at
. . The relationship aj112' is expressed as shown in the diagram. Further, when a retarder brake is used, when the retarder switch 13 is turned on, a maximum rotation command signal VmQ# is manually inputted to the circuit 14 in contrast to the deviation signal V#. Drive circuit 1
4 outputs the maximum value 'ram of the III# signal when input signal MA is applied to control the swash plate angle of the hydraulic pump 22 to the maximum, thereby maximizing the pump discharge amount. Therefore, the instantaneous interception of the cooling fan 2 becomes the highest, and the amount of air blown to the radiator 1 becomes the maximum.As a result, the cooling of the hydraulic oil during play in the oil and Rugula 4 reaches the maximum '1. , it is possible to suppress the temperature rise of the brake hydraulic fluid. Of course, the cooling effect of the engine 3 is also increased. At tI4, the load of the air cooling fan 2 on the engine 3 reaches its maximum. In the present embodiment M, a case has been described in which the retarder brake hydraulic oil is also cooled, but the present invention is not limited to this, and it goes without saying that only the engine may be cooled. As explained above, according to the present invention, by controlling the amount of air blown to the two radiators according to the engine cooling water temperature and maintaining the cooling water temperature at a predetermined temperature, carrots can be grown with maximum efficiency! engine loss horse m,
, lower the energy and make the energy more effective. It can be used for Furthermore, since the cooling fan is driven by a hydraulic motor, there are advantages such as improved K11l readiness.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the cooling fan automatic control device according to the present invention, and Fig. 2 is a diagram showing the relationship between the swash plate angle of the hydraulic pump of the device shown in Fig. 1 and the cooling water temperature. . 1-・Radiator, 2-・Cooling fan, 3**Engineering, 4-・Brake oil cooler, , 5 dl
l oil tank, 6, 7-retarder brake, 12-・
-Amplifier, 13--Retarder switch, 14-@-Drive circuit, 1.5--Water temperature 7-pin 21" hydraulic motor, 22-Hydraulic pump, 23--Napo valve. ! Figure 2 Rei Oshi water temperature (0C) Procedural amendment April 1980 Nnn Date 1, Indication of the case 2, Name of the invention Cooling fan automatic control device 3, Person making the amendment Relationship to the case Patent applicant (123) Komatsu Ltd. 4, Agent (Address: 104) 2-11-2-6, Ginza, Chuo-ku, Tokyo Contents of amendment (1) From page 5, line 1 to page 5, line 2 and 2 of the specification of the application 5th page 2nd line to 5th page 3rd line and 5th page 6th line to 5th page 7th line and 5th page 12th line to 5th page 13th line and 6th page 6th line and 7th page Page 15th line to 7th page 16th line and 9th page
Correct "retarder switch" in the 9th line of the page to "control signal changeover switch". <2) Same, page 4, line 17 to page 4, line 20, ``The difference ε is ~ with the polarity of the input signal ε'', and the difference ε is the difference between the gain − and the amplifier 12 with a The signal is amplified and output as 1ε. Here, since the gain of the amplifier 12 is negative, the polarity of the output signal -1ε is corrected to be the polarity of the deviation ε. (3) Correct the [deviation signal Vε] in the first line of the fifth page to "signal - 1ε". (4) Same, page 5, 13tTb et al., page 5, 14
The "deviation signal Vε" in the row is corrected to "input signal -1ε". (5) Same, page 6, line 10, “ha-■ε” is r
K+ ε is θ polarity”. (6) Same, page 6, line 12, “ru.” and “obite”
Insert between the lines ``[However, the input/output characteristics of the drive circuit ''14 shall be as shown in FIG. 3.'' (7) Same, change the “deviation signal Vε” in the 20th line of the 6th page to [
amplification! The output signal of 112 is corrected to 1ε. (8) Same, change "input signal ■ε" in the first line of page 7 to "
The input signal is corrected to -1ε. (9) Same, page 7, line 2, after “Add to.” [
The input/output characteristics of this drive circuit 14 are shown in FIG. ” is added. (10) Correct "deviation signal ■ε" in the 16th line of page 7 to "signal - 1ε". (11) In the 8th page, line 12, after ``Of course.'', add ``Accordingly, depending on the purpose, the water temperature sensor 15 may be installed near the engine outlet 10.''``'' (12) In the same page, page 9, line 5, after ``This is a diagram showing.'' [FIG. 3 also shows the input/output characteristics of the drive circuit 14. ” is added. (13) The first figure τ of the drawings attached to the specification of the present application:
11:::222722;. , 1,3°. Add as shown in the attached sheet. Figure 2 Figure 3

Claims (1)

[Claims] A water temperature sensor that detects the cooling water temperature of the radiator population, a control circuit that outputs a control signal according to the difference between the output of the water temperature sensor and a reference value, and a control circuit that outputs a control signal according to the difference between the output of the water temperature sensor and a reference value.
a variable displacement hydraulic pump controlled by the control signal I;
A hydraulic motor drives a cooling fan in response to the discharge amount of the hydraulic pump, and the amount of air blown to the radiator is controlled in accordance with the cooling water temperature, thereby controlling the armpit cooling water temperature to a predetermined temperature. Cooling fan automatic control device.