JPH05931U - Forced circulation type water cooling system for engine - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent both engine overheat under high torque operation and overcooling under high power operation. [Structure] A pump drive shaft 4 of a water pump 3 is interlockingly connected to a crankshaft 2 of an engine 1 via a transmission 5. The transmission 5 is linked to the engine torque detecting means 8 via the shift operating device 6 and the shift control device 7.
When the detected torque value of the engine torque detecting means 8 is low, the gear shift control device 7 operates the gear shift device 5 to the low speed conduction state via the gear shift operation device 6. On the other hand, when the detected torque value is high, the transmission 5
Is configured to operate in the fast conduction state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a forced circulation type water cooling device for an engine.

[0002]

[Prior Art]

 In the prior art, the forced circulation type water cooling device for an engine of the present invention may have the following structure, for example, as shown in FIG. That is, the pump drive shaft 4 of the water pump 3 is interlockingly connected to the crankshaft 2 of the engine 1 via the belt transmission device 20 at a constant transmission ratio.

[0003]

[Problems to be solved by the device]

 The above-mentioned conventional technique has a problem that overheating occurs during high torque operation or overcooling occurs during high output operation. (A) When the discharge capacity of the water pump 3 is set so that proper cooling can be obtained in the high output operating state, the engine 1 may overheat in the high torque operating state. As shown in FIG. 3 (A), the high output operating state H is in the high speed operating region, and as shown in FIG. 3 (B), it is considerably lower than the high torque value Th of the high torque operating state M, and thus the low torque is low. The value is Tl. In a unit period per explosion of the engine 1, the unit heat generation amount of the low torque value Tl and the unit cooling water amount of the water pump 3 are balanced, and the engine 1 is properly cooled. When the high output operating state H is changed to the high torque operating state M, as shown in FIG. 3B, the low torque value Tl is increased to the high torque value Th. The unit heat generation amount becomes excessive by the torque increase Tu, and the engine 1 overheats. (B) When the discharge capacity of the water pump 3 is set to be large so that proper cooling can be obtained in the high torque operation state M, excessive cooling occurs in the high output operation state H, and the combustion performance deteriorates. In the high torque operating state M, the unit heat generation amount of the high torque value Th and the unit cooling water amount of the water pump 3 are balanced, and the engine 1 is appropriately cooled. When the high torque operating state M is changed to the high output operating state H, the high torque value Th is reduced to the low torque value Tl. The unit heat generation amount is reduced by this torque reduction amount Tu, the engine 1 is excessively cooled, and the combustion performance is reduced. An object of the present invention is to achieve both prevention of overheat in a high torque operation state and prevention of supercooling in a high output operation state.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention adds the following characteristic structure as shown in FIGS. 1 and 2, for example. A pump drive shaft 4 of a water pump 3 is interlockingly connected to a crankshaft 2 of an engine 1 via a transmission 5. Then, the transmission 5 is made to cooperate with the engine torque detecting means 8 via the shift operation device 6 and the shift control device 7. When the detected torque value of the engine torque detecting means 8 is low, the shift control device 7 operates the transmission device 5 to the low speed transmission state via the shift operation device 6. On the other hand, when the detected torque value is high, the transmission 5 is configured to operate in the high speed transmission state.

[0005]

[Action]

 The present invention works as follows. (A) High output operating state In the high output operating state H, as shown in FIG. 3 (B), the low torque value Tl is considerably lower than the high torque value Th of the high torque operating state M, and the engine 1 has a low torque value Tl. The unit calorific value per explosion is small. At this time, the detected torque value of the engine torque detection means 8 detects the low torque value Tl, and the shift control device 7 operates the shift device 5 in the low speed transmission state via the shift operation device 6. Then, the unit cooling water amount of the water pump 3 per unit period per explosion of the engine 1 becomes small. This lower unit cooling water amount balances with the lower unit heat generation amount described above to properly cool the engine 1 and prevent deterioration of combustion performance due to supercooling. (B) High-torque operation state In the high-torque operation state M, the high torque value Th is reached and the unit heat generation amount is large. At this time, the detected torque value of the engine torque detection means 8 detects the high torque value Th, and the shift control device 7 operates the transmission device 5 in the high-speed transmission state via the shift operation device 6. Then, the unit cooling water amount of the water pump 3 per unit period of one explosion of the engine 1 becomes large. The larger unit cooling water amount balances with the larger unit heat generation amount to properly cool the engine 1 and prevent overheating.

[0006]

[Effect of the device]

 The present invention has the following effects because it is configured and operates as described above. (A) Prevention of overcooling in high output operation state When the detected torque value of the engine torque detection means is low, the gear shift control device operates the gear shift device to the low speed transmission state via the gear shift operation device to set the water transmission. Reduce the unit cooling water volume of the pump. As a result, in the high output operation state, the unit heat generation amount per explosion is small due to the low torque value, while the unit cooling water amount is set to be small and balanced as described above, so that the engine is properly cooled. It is possible to prevent deterioration of combustion performance due to supercooling. (B) Prevention of overheat in a high torque operation state When the torque detection value of the engine torque detection means is high, the gear shift control device operates the gear shift operation device to the high speed transmission state via the gear shift operation device, and the water pump Unit: Increase the amount of cooling water. As a result, in the high torque operation state, the unit heat generation amount per explosion is increased due to the high torque value, while the unit cooling water amount is increased and balanced as described above. Can cool properly and prevent overheating.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (A) is a schematic side view of a water-cooled engine, FIG. 1 (B) is an operation explanatory view of a transmission of a water pump drive shaft, and FIG. 2 is a front view of the water-cooled engine. In the figure, a radiator 11 is arranged in front of the water-cooled engine 1, a cooling fan 10 is exposed in the rear of the radiator 11, and a water pump 3 is provided in front of the engine 1. The discharge port 3a of the water pump 3 communicates with the inlet 13 of the water jacket 12 of the engine 1, and the inlet 3b of the water pump 3 communicates with the lower tank 11b of the radiator 11, and The outlet 14 of the water jacket 12 is connected to the upper tank 11a of the radiator 11 via a thermostat chamber 15. Further, a thermostat 16 is attached to the thermostat chamber 15, and the thermostat chamber 15 is connected to the pump chamber 3c of the water pump 3 through a bypass passage 17. As a result, when the engine 1 starts cold, the thermostat 16 is opened to the side of the bypass path 17 and the engine cooling water is circulated in the water jacket 12 of the engine 1 in a closed loop shape without flowing to the radiator 11 to warm it. It is designed to promote machine operation. A fan pulley 18 is attached to the front wall of the engine 1 via a bearing, and the cooling fan 10 is fixed in front of the fan pulley 18.

Further, a transmission 5 is attached to the pump drive shaft 4 of the water pump 3. The speed change device 5 is composed of, for example, a continuously variable speed change pulley 19, and one side 19a of the pulley is moved in the thrust direction to change the hanging width of the belt transmission device 20 to change the effective diameter of the pulley and to the engine 1. The rotation ratio of the water pump 3 can be continuously varied. The transmission 5 is connected to the crankshaft 2 of the engine 1 by a belt transmission device 20, and the fan pulley 18 is connected by a transmission belt 21. Further, the transmission 5 is linked to the engine torque detecting means 8 via the shift operating device 6 and the shift control device 7. The engine torque detecting means 8 detects the exhaust gas temperature of the exhaust manifold 22 of the engine 1 by a temperature sensor 23, for example. When the torque of the engine 1 is high, the amount of heat generated is large and the exhaust gas temperature is also high, so the detected torque value of the engine torque detecting means 8 is high. The temperature of the exhaust gas detected by the temperature sensor 23 is calculated by the calculator 25 in the shift control device 7, and the push rod 26 is moved back and forth via the motor 24 of the shift operating device 6. When the detected torque value is high, the gear ratio is increased by pulling the pulley piece side 19a of the transmission 5, and the transmission is operated in the high speed transmission state. On the other hand, when the detected torque value is low, the gear ratio is reduced by pushing the pulley piece side 19a of the transmission 5 to operate in the low speed transmission state. Reference numeral 19b is a collar, reference numeral 19c is a nut, and reference numeral 27 is a tension pulley which also serves as a drive pulley for a dynamo or the like.

[Brief description of drawings]

1 shows an embodiment of the present invention, FIG. 1 (A) is a schematic side view of a water-cooled engine, and FIG. 1 (B) is an operation explanatory view of a transmission device of a pump drive shaft.

FIG. 2 is a front view of the water-cooled engine according to the embodiment of the present invention.

FIG. 3 is a torque characteristic diagram of the engine.

FIG. 4 is a diagram showing a conventional example and corresponding to FIG.

[Explanation of symbols]

1 ... Engine, 2 ... Crankshaft, 3 ... Water pump,
4 ... Pump drive shaft, 5 ... Transmission, 6 ... Transmission operating device,
7 ... Shift control device, 8 ... Engine torque detecting means.

Claims (1)

[Claims for utility model registration] 1. A pump drive shaft (4) of a water pump (3) is interlockingly connected to a crank shaft (2) of an engine (1) through a transmission (5). The transmission device (5) is connected to the engine torque detecting means via the transmission operating device (6) and the transmission control device (7).
When the detected torque value of the engine torque detecting means (8) is low, the speed change control device (7) transmits the speed change device (5) at a low speed via the speed change operation device (6). When the detected torque value is high, the transmission (5) is operated to a high-speed transmission state.