CN1319716A - Cooling water temp. stabilizer for water cooling type engine - Google Patents

Abstract

To prevent the amount of cooling water from reducing in a cooling water circulation between a radiator and a water jacket, and stabilize the temperature of the cooling water in a water-cooled engine with the water jacket for circulating the cooling water in a space toward the radiator in an engine body. A control unit 75 controls an engine control means 76 to reduce the output of the engine responding to the detected temperature by a temperature detector 74, which detects a temperature representing the water temperature in the water jacket 62, reaching the set temperature set to a value corresponding to the boiling temperature of the cooling water in the water jacket.

Description

Cooling water temperature stabilizing device for water-cooled engine

The invention relates to a device for stabilizing the temperature of the cooling water in a water-cooled engine in which the cooling water circulating between the radiator and the radiator is set in a water-cooled engine.

In the prior art, in such a water-cooled engine, as shown in Japanese Patent Laid-Open No. 3-64621, the temperature of the cooling water in the radiator is detected, and the electric fan is rotated according to the inspection result. This prevents the temperature of the cooling water from rising.

However, the temperature of the cooling water in the cooling water circulation circuit between the radiator and the water jacket will rise due to the abnormality of the above-mentioned electric fan, etc., such as an increase in evaporation from the radiator cover. The amount of cooling water in the cooling water circulation circuit between the radiator and the water jacket is reduced. Therefore, it is difficult to accurately detect the reduction of cooling water if the rotation of the electric fan is controlled only based on the temperature of the cooling water in the radiator.

The present invention is made in view of the above problems, and an object of the present invention is to provide a cooling water temperature stabilizing device for a water-cooled engine that can prevent a decrease in the amount of cooling water in the cooling water circulation circuit between the radiator and the water jacket and can stabilize the cooling water temperature.

In order to achieve the above-mentioned purpose, the invention described in the present invention's scheme 1 is that in the water-cooled engine that circulates cooling water between the radiator and the water-cooled engine on the engine body, there is: an engine control device that can change the output power of the engine, A temperature detector that can detect the temperature representing the temperature of the water in the water jacket, and control the control unit of the aforementioned engine control device to reduce the output power of the aforementioned engine according to the detected temperature of the aforementioned temperature detector reaching the set temperature; it is characterized in that the aforementioned device The fixed temperature is set to a temperature value corresponding to the boiling temperature of the cooling water in the aforementioned water jacket.

According to this constitution, when the detection value of the temperature detector detecting the temperature representing the water temperature in the water jacket reaches the temperature corresponding to the boiling temperature of the cooling water in the water jacket, the control part controls the engine control device to reduce the engine output power, because of this, It can prevent the cooling water in the water jacket from continuously boiling, suppress the evaporation of cooling water from the radiator, prevent the reduction of cooling water in the cooling water circulation circuit between the radiator and the water jacket, and stabilize the temperature of the engine cooling water.

The feature of the invention described in the scheme 2 of the present invention is that, on the basis of the invention described in the scheme 1, the aforementioned temperature detector can directly detect the water temperature in the aforementioned water jacket and be installed on the engine body; Rapidly detect boiling of the cooling water in the cooling water circulation loop between the radiator and the water jacket.

The invention described in claim 3 of the present invention is characterized in that, in addition to the invention described in claim 1, a centrifugal motor that transmits power as the engine speed increases is provided between the aforementioned engine mounted on the vehicle and the drive wheels. Clutch, when the engine control device controlling the ignition is controlled by the aforementioned control part to reduce the engine output power, the engine speed can be reduced to a set speed that exceeds the engagement rotation of the aforementioned centrifugal clutch; While reducing the engine output, the driver correctly detects the control state.

The feature of the invention described in Scheme 4 of the present invention is that, on the basis of the invention described in Scheme 2, the aforementioned temperature detector can directly detect the water temperature at the inner bottom of the aforementioned water jacket and be installed on the engine body; Composition, even if the cooling water decreases, it can definitely detect the boiling of the cooling water.

The feature of the invention described in claim 5 of the present invention is that, on the basis of the invention described in claim 1 above, in order to make the heat dissipation of the radiator usually larger than the calorific value of the aforementioned engine, a linkage is attached to the radiator. The cooling fan connected to the crankshaft; according to this structure, since the cooling water does not boil under normal conditions, it can correctly detect the boiling of the cooling water in the cooling water circulation circuit as the cooling water decreases, and prevent the cooling water in the water jacket from continuing to boil , and prevent the reduction of cooling water in the cooling water circulation circuit, and stabilize the engine cooling water temperature.

Fig. 1 is an overall side view of a small motorcycle type motorized two-wheeled vehicle; Fig. 2 is a sectional enlarged view of 2-2 of Fig. 1; Fig. 3 is an enlarged view of the main part of Fig. 2; Fig. 4 is a sectional view of 4-4 of Fig. 2; Fig. 5 is a view of power components viewed from the sectional direction of 5-5 in FIG. 1; FIG. 6 is a diagram of an engine control system; FIG.

The implementation form of the present invention will be described below by means of an embodiment shown in the accompanying drawings.

1 to 7 show an embodiment of the present invention. Fig. 1 is an overall side view of a scooter-type motorized two-wheeled vehicle, Fig. 2 is an enlarged sectional view of 2-2 of Fig. 1 , Fig. 3 is an enlarged view of essential parts of Fig. 2 , and Fig. 4 is a sectional view of 4-4 of Fig. 2 , Fig. 5 is a sectional view of the power part according to 5-5 in Fig. 1, Fig. 6 is a diagram of the engine control system, and Fig. 7 is a diagram showing the detected temperature and the control time corresponding to the on/off of the main switch.

First, in FIG. 1 , the body frame F of a scooter-type two-wheeled motor vehicle V having a front wheel Wf manipulated by a steering handle 11 and a rear wheel Wr driven by a swing-type power unit P is divided into a front frame 12. 1. The central frame 13 and the rear frame 14 are three parts. The front frame 12 is constituted by an aluminum alloy casting integrally having a head pipe 12a, a down pipe 12b, and a pedal support portion 12c. The center frame 13 that supports the power unit P so that it can freely swing up and down through the pivot shaft 15 is made of an aluminum alloy casting and is joined to the rear end of the front frame 12 . A rear frame 14 extending rearward and upward of the power unit P is formed of an annular pipe, and supports a fuel tank 16 thereon. A helmet box 17 is supported on the center frame 13, and the helmet box 17 and the fuel tank 16 are covered by a cover 19 integrally provided with a seat 18 in a freely openable and closable manner.

The power unit P is composed of a water-cooled single-cylinder four-cycle engine E with its cylinder facing the front of the vehicle body, and a belt-type continuously variable transmission T extending from the left side of the engine E to the rear of the vehicle body. The belt-type continuously variable transmission T The rear upper surface of the upper part is combined with the rear end of the center frame 13 through the rear buffer 20 . The air filter 21 is supported on the belt type continuously variable transmission T, the muffler 22 is supported on the right side of the belt type continuously variable transmission T, and the standable and fallable engine E is supported under the engine E. Main support 23.

2 to 4, the engine body 24 of the engine E has first and second engine bodies 27, 28 divided by a dividing plane 26 extending vertically along the crankshaft 25, and the first engine body 27 constitutes a The cylinder block 27a and the crankcase half 27b; the second engine block 28 constitute the other half of the crankcase. The cylinder head 29 which forms the engine body 24 together with the first and second engine bodies 27 and 28 is combined at the front end of the first engine body 27; A generator cover 31 is attached to the right sides of the first and second engine bodies 27 and 28 .

The belt-type continuously variable transmission T has a right side case 32 and a left side case 33 that are combined with each other. The right side of the front part of the right casing 32 is combined with the left sides of the first and second engine bodies 27 and 28 . And the rear portion right side of the right side housing 33 is combined with the reducer housing 34 .

A piston 36 slidably fitted inside a cylinder 35 provided in the first engine block 27 is connected to the crankshaft 25 through a connecting rod 37 . A camshaft 38 is rotatably supported on the cylinder head 29 , and an intake valve and an exhaust valve (not shown) provided on the cylinder head 29 are driven to open and close by the camshaft 38 . In the chain passage 39 provided in the first engine body 27, a timing chain 40 is accommodated, and the timing chain 40 is wound around a driving sprocket 41 provided on the crankshaft 25 and a driven sprocket 42 provided on the camshaft 38. superior. Thus, for every two revolutions of the crankshaft 25, the camshaft 38 makes one revolution.

A drive pulley 43 is provided at the left end of the crankshaft 25 protruding from the inside of the right side housing 32 and the left side housing 33 . The drive pulley 43 has a fixed side pulley half 44 fixed to the crankshaft 25, and a movable side pulley half 45 that can approach and separate from the fixed side pulley half 44; The centrifugal counterweight 46 that moves radially outward when the rotational speed increases by 25 energizes it in a direction approaching the fixed-side pulley half body 44 .

The driven pulley 48 that is arranged on the output shaft 47 supported between the rear portion of the right side housing 32 and the reducer housing 34 has a fixed side pulley half 49 relatively rotatably supported on the output shaft 47, and a The movable pulley half 50 approaching and away from the fixed pulley half 49 is energized by the spring 51 from the movable pulley half 50 to the fixed pulley half 49 . Further, between the fixed-side pulley half 49 and the output shaft 47, there is provided a centrifugal clutch 52 that is in a power transmission state when the engine speed exceeds a set speed. An endless V-belt 53 is wound between the driving pulley 43 and the driven pulley 48 .

Between the right side housing 32 and the speed reducer housing 34, an intermediate shaft 54 parallel to the aforementioned output shaft 47 and an axle 55 are supported; A rear wheel Wr serving as a driving wheel is provided at the right end of the axle 55 protruding rightward through the reduction gear case 34 .

The rotational power of the crankshaft 25 is transmitted to the drive pulley 43, and then passed to the rear wheel Wr from the aforementioned drive pulley 43 through the V-belt 53, the driven pulley 48, the centrifugal clutch 52 and the reduction gear train 56.

The alternator 57 provided on the right side of the crankshaft 25 is covered by the generator cover 31 , and a radiator 58 is provided on the right side of the generator cover 31 . In order to supply cooling air to the radiator 58 , a cooling fan 59 fixed to the right end of the crankshaft 25 is arranged between the alternator 57 and the radiator 58 . Therefore, the heat radiation of the radiator 58 is larger than the heat generation of the engine E at ordinary times.

The cooling fan 59 and the radiator 58 are covered with a synthetic resin cover 60 connected to the generator cover 31 , and vent windows 61 for introducing air from the outside are provided on the outer surface of the cover 60 .

A water jacket 62 is provided on the cylinder block 27 a of the first engine block 27 and the cylinder head 29 , and a cooling water pump 63 for sucking cooling water in the water jacket is connected to the right end of the camshaft 38 . Whether the cooling water discharged from the cooling water pump is introduced into the aforementioned radiator 58 should be switched by the thermostat 64 according to the temperature of the cooling water. The thermostat housing 65 housing the thermostat 64 is combined with the right side of the cylinder head 29. The aforementioned cooling water pump 63 is accommodated in a space surrounded by the cylinder head 29 and the thermostat housing 65 .

Referring to FIG. 5 together, the front lower part of the radiator 58 is connected to the thermostat housing 65 by the cooling water pipeline 66 ; and the thermostat housing 65 is connected to the water jacket 62 in the first engine body 27 by the cooling water pipeline 67 .

The rear fender 68 covering the rear wheel Wr from above is swingably attached to the power unit P together with the radiator 58, and is connected to the water supply port provided at the rear upper part of the radiator 58 through a water supply line 69 having a flexible rubber hose. The nozzle 70 of 58a is detachably connected to the rear fender 68 . The upper end opening of the nozzle 70 is closed openably and closably by a cover 71 .

An overflow pipe 70a for overflowing cooling water is provided on the nozzle 70, and the overflow pipe 70a is connected to a storage tank not shown in the figure. The nozzle 70 is connected with the water jacket 62 in the cylinder head 29 by a cooling water pipeline 72 having the flexibility of a rubber hose.

At the end of engine warm-up operation, the cooling water discharged from the cooling water pump 63 driven by the camshaft 38 is supplied to the first engine body 27 and the water jacket 62 in the cylinder head 29 through the thermostat housing 65 and the cooling water pipeline 67. After cooling the engine E through the water jacket, it is fed into the radiator 58 through the cooling water pipeline 72 , the pipe joint 70 and the water supply pipeline 69 . Then the cooling water whose temperature has been reduced during passing through the radiator 58 returns to the aforementioned cooling water pump 63 through the cooling water pipeline 66 and the thermostat 64 . On the other hand, if the cooling water temperature is low during the warm-up operation of the engine E, the thermostat 64 is activated, and the cooling water circulates inside the engine E without passing through the radiator 58, and the temperature rises rapidly.

In FIG. 6 , the operation of the engine E is controlled by the control unit 75 , and the current from the battery 77 is supplied to the control unit 75 through the main switch 78 . In addition, the DC power obtained by rectifying the AC power generated by the alternator 57 by the regulator 79 is used to charge the battery 77 .

In addition, the main switch 78 is connected to a parallel circuit composed of a stop switch 80 that is turned on in response to the brake operation on the front wheel side and a stop switch 81 that is turned on in response to the brake operation on the rear wheel side. When the switch 78 is turned on, at least one of the aforementioned two stop switches 80 and 81 is turned on to turn on the stop lamp 82 .

The parallel circuit formed by the aforementioned two stop switches 80, 81 is connected to the control unit 75 through the start switch 83, and at least one of the two stop switches 80, 81 is in a conduction state, that is, at least one of the front wheel side and the rear wheel side performs braking. The start switch 83 is actuated in a state of being actuated, whereby a signal instructing the start of the engine E is input to the control unit 75 . The control unit 75 controls the relays 84, 85, and 86 based on the input signal to activate the starter motor 87 to start the engine E.

In addition, on the control part 75, there are a signal from a pulse generator 88 that detects the rotational speed of the engine E, a detection signal from a fuel detector 89 that detects the remaining amount of fuel in the fuel tank 16, and a detection signal for detecting the throttle valve closed according to the throttle valve. A detection signal of a throttle sensor 90 that operates a throttle opening at which the engine is once stopped is input to the control section 75 .

On the carburetor (not shown in the figure) installed in the air intake system of the engine E, there is a bypass starter device 91 that controls the fuel supply amount at startup according to the expansion and contraction of the wax heated by the PTC heater. , the aforementioned PTC heater of the bypass starter 91 is also controlled by the control unit 75 .

Furthermore, the detection value of the temperature detector 74 for detecting the temperature representing the temperature of the water in the water jacket 62 is input to the control unit 75, and the control unit 75 controls the engine as a variable output power of the engine E according to the detection value of the temperature detector 74. The ignition device 76 of the control device.

That is, as shown in FIG. 7 , according to the detected temperature of the aforementioned temperature detector 74, the set temperature Ts (such as 130° C.) corresponding to the boiling temperature value of the cooling water in the water jacket 62 is set, and the control unit 75 controls the ignition device 76 Intermittent ignition (ignition を between lead <) reduces engine E output power and makes it reach such as motorized two-wheel vehicle walking speed to about 30km/h. Such a control state is terminated by turning off the main switch 78 to stop the ignition.

In addition, the control means 75 controls the turning on and off of the indicator lamp 92 shown in FIG.

As shown in Figure 3, the aforementioned temperature detector 74 directly detects the water temperature in the water jacket 62 and is installed on the cylinder block 27a of the engine body 24, and the temperature detector 74 directly detects the water temperature at the bottom of the water jacket 62 and is installed on the On the aforementioned cylinder block 27a.

Next, the function of this embodiment will be described. When the detection value of the temperature detector 74, which detects the temperature representing the temperature of the water in the water jacket 62, reaches the set temperature TS corresponding to the boiling temperature of the cooling water in the water jacket 62, the control unit 75 operates to reduce the output power of the engine E. Control the ignition device to perform intermittent ignition, so that the cooling water in the water jacket 62 can be prevented from continuously boiling, the cooling water from the radiator 58 can be suppressed from evaporating, and the amount of cooling water in the cooling water circulation circuit between the radiator 58 and the water jacket 62 can be prevented from decreasing, thereby stabilizing Cooling water temperature of engine E.

In addition, since the temperature detector 74 can directly detect the water temperature in the water jacket 62 and is installed on the cylinder block 27a of the engine body 24, it can quickly detect the boiling of the cooling water in the cooling water circulation circuit between the radiator 58 and the water jacket 62; And because the temperature detector 74 can directly detect the water temperature at the bottom of the water jacket 62, even if the cooling water in the cooling water circulation circuit decreases, the boiling of the cooling water can be detected reliably.

Also, since the radiator 58 is provided with a cooling fan 59 interlocked and connected to the crankshaft 25, the heat dissipation of the radiator 58 is always larger than the heat generated by the engine E at ordinary times. Therefore, boiling of the cooling water will not occur under normal conditions. Since the boiling caused by the reduction of the cooling water in the aforementioned cooling water circulation loop can be accurately detected, it is possible to prevent the cooling water in the water jacket 62 from continuously boiling and prevent the cooling water circulation loop from boiling. The reduction of the amount of internal cooling water can stabilize the engine E cooling water temperature.

As other embodiments of the present invention, it is also possible not to reduce the output power of the engine E by intermittent ignition, but to control the aforementioned ignition device 76 to implement a staged flameout, so that the engine speed is reduced to a value exceeding that of the centrifugal clutch 52. Set the speed; if so, the control state can be accurately detected while driving while slowly reducing the engine output.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various design changes can be made without departing from the content of the present invention described in the claims.

As mentioned above, according to the invention of Scheme 1, the cooling water in the water jacket can be prevented from continuously boiling, the cooling water can be suppressed from evaporating from the radiator, the amount of cooling water in the cooling water circulation circuit between the radiator and the water jacket can be prevented from decreasing, and the temperature of the engine cooling water can be stabilized. .

According to the invention of scheme 2, the boiling of the cooling water in the cooling water circulation loop between the radiator and the water jacket can be quickly detected.

According to the invention of claim 3, the driver can accurately detect the control state while gradually reducing the engine output.

According to the invention of claim 4, even if the cooling water decreases, boiling of the cooling water can be reliably detected.

According to the invention of scheme 5, the boiling of the cooling water in the cooling water circulation circuit can be accurately detected, the cooling water in the water jacket can be prevented from continuously boiling and the cooling water in the cooling water circulation circuit can be prevented from decreasing, and the temperature of the engine cooling water can be stabilized.

Claims (5)

1. the cooling water temperature stabilizer of a water-cooled engine, be provided with on the engine body (24) and radiator (58) between the water jacket (62) of recirculated cooling water, it is characterized in that, it has: can change motor (E) output power engine controlling unit (76), be used for detecting the Temperature Detector (74) of the temperature of interior the water temperature of representative aforementioned water jacket (62), along with the detected temperatures of this Temperature Detector (74) reaches setting temperature, control the controlling component (75) that aforementioned engine controlling unit (76) makes aforementioned motor (E) reduction output power; Aforementioned setting temperature is set to the value corresponding to the cooling water boiling temperature in the aforementioned water jacket (62).

2. by the described water-cooled engine cooling water temperature of claim 1 stabilizer, it is characterized in that aforementioned temperature detector (74) can directly detect the interior water temperature of aforementioned water jacket (62), and is installed on the engine body (24).

3. by the described water-cooled engine cooling water temperature of claim 1 stabilizer, it is characterized in that, between aforementioned motor (E) that is equipped on vehicle and driving wheel (Wr), centrifugal clutch (52) along with engine speed rising transferring power is being set, the aforementioned engine controlling unit (76) of control ignition, when reducing the output power of motor (E) by aforementioned controlling component (75) control, the setting rotating speed that the joint that engine speed is reduced to surpass aforementioned centrifugal clutch (52) rotates.

4. by the described water-cooled engine cooling water temperature of claim 2 stabilizer, it is characterized in that aforementioned temperature detector (74) can directly detect aforementioned water jacket (62) inner bottom part water temperature, and be installed on engine body (24).

5. by the described water-cooled engine cooling water temperature of claim 1 stabilizer, it is characterized in that, usually the heating value than aforementioned motor (E) is also big for the heat dissipating capacity that makes radiator (58), is setting up the cooling fan (59) that interlock is linked to bent axle (25) on aforementioned radiator (58).

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