JP2002364443A - Engine control device for small-sized snowmobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine control device for small-sized snowmobile in which generation of engine overheat is surely prevented even when being left in an idle state over a long time. SOLUTION: This small-sized snowmobile comprises the engine control device which includes: an idle switch 52 which detects an idle operating state from an engine speed; a stop state detection part which detects a running stop state; a cooling water temperature detection sensor 46; and an engine control unit 48 which is capable of stop control of an engine operation by ignition cut and fuel cut. The unit 48 carried out the engine stop control under a condition that a small-sized snowmobile stopping state, the engine idle operating state, and a state of cooling water temperature being more than a set temperature continue more than a set time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled engine provided in an engine room at a front part of a vehicle body, and a heat exchanger at a rear part of a rear part of the vehicle body above a traveling trail (also referred to as a crawler or a track belt). The present invention relates to an engine control device for a small snowmobile equipped with a water-cooled engine that circulates cooling water through a changer and cools the cooling water by snow scooped by a trail during traveling.

[0002]

2. Description of the Related Art In general, a small snowmobile such as a snowmobile equipped with a water-cooled engine has an engine room shape that emphasizes traveling performance, so that a radiator mounted on a four-wheeled vehicle or the like in order to improve space. And without a fan, instead, a heat exchanger is mounted under the seat, so that the snow scavenged by the trail (also referred to as a crawler) during running falls on the heat exchanger located above the trail, The cooling water exchanges heat with snow to cool it down.

In a small snowmobile, the cooling water circulation system
A thermostat (valve) for switching the flow of the cooling water according to the temperature of the cooling water is provided similarly to the cooling water circulation system of a vehicle such as a four-wheel vehicle. The cooling water is circulated through the heat exchanger when the temperature of the cooling water becomes equal to or higher than a predetermined temperature.

In a general small snowmobile, when the warm-up is insufficient immediately after the start, the thermostat is closed, and the cooling water circulates in the engine water jacket without warming to the heat exchanger and warms up. After that, when the warm-up is sufficiently advanced, the thermostat is opened to turn the cooling water to the heat exchanger to cool it, and to send the cooled water to various parts of the engine.

[0005]

However, since the heat exchanger exchanges heat between the snow scavenged by the small snowmobile and the cooling water, the heat exchanger stops the small snowmobile such as in an idle state. When the engine is running in this state, the snow is hardly lifted, and the heat exchanger cannot exchange heat with the snow, and must radiate heat to the vehicle body and the outside air. Therefore, when the snowmobile stops for a long time, the cooling water is circulated to the engine in a state of insufficient cooling, and the cooling water temperature rises.

However, in the conventional snowmobile, even if the cooling water temperature rises when the cooling water temperature rises in an idle state, the user is warned by the pointer of the water temperature gauge entering a so-called red zone (warning display). Was not implemented. For this reason, if the small snowmobile is stopped and left idle for a long time in an idle state ignoring that the water temperature gauge has entered the red zone, the engine may malfunction due to overheating.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides an engine control apparatus for a small snowmobile capable of reliably preventing engine overheating even when left idle for a long time. The purpose is to do.

[0008]

The present invention has the following structure to achieve the above object. The present invention provides a water-cooled engine in the engine room at the front of the vehicle body, and a heat exchanger above the running trail at the rear of the vehicle body,
In a small snowmobile equipped with a water-cooled engine, in which cooling water is circulated through the heat exchanger to cool the cooling water by snow scooped up by the trail during traveling, an idle state for detecting an idle operation state of the engine. An engine control unit comprising: a detection unit; a stop state detection unit for detecting a stop state of the traveling of the small snowmobile; a cooling water temperature detection unit; and an engine control unit capable of controlling stop of the engine operation by ignition cut or fuel cut. Is characterized in that the engine is controlled to stop on condition that the small snowmobile is in a stopped state, the engine is in an idling operation state, and that the cooling water temperature is equal to or higher than a set temperature for a set time or longer. It has a configuration of an engine control device for a snowmobile.

In general, in a small snowmobile with a water-cooled engine, instead of cooling the cooling water circulating in the radiator by blowing air from a fan as in a four-wheeled vehicle, the cooling water circulates in a heat exchanger using snow scooped up by a trail. Cooling water. Therefore, when the small snowmobile is stopped and idling, snow cannot be lifted from the trail, so that the cooling water in the heat exchanger is not cooled. In this state, the engine water temperature becomes too high and there is a possibility of overheating. The present invention has been made by paying attention to such problems. According to the present invention,
The engine control unit controls the stop of the engine on the condition that the snowmobile is stopped, the engine is in the idle state, and the cooling water temperature is equal to or higher than the set temperature for a set time or longer. Even when the engine is stopped and the engine is idle, engine overheating can be reliably prevented.

The state in which the snowmobile is stopped can be dealt with by detecting the speed 0 by the vehicle speed sensor. However, the present invention can also be applied to the case where the vehicle speed sensor is not provided by the following configuration. In other words, an automatic clutch means for disengaging / connecting the engine at a speed lower than or equal to a set number of revolutions provided on a driving force transmission mechanism from the engine of the small snowmobile to the trail, and a means for detecting the engine speed are provided. The stop state detecting means includes:
The stop state of the snowmobile can be detected on the condition that the detected engine speed is less than the set speed of the automatic clutch release. With this configuration, there is no need to provide a vehicle speed sensor, and the existing automatic clutch means and engine speed detection means can be used in a small snowmobile. Can be prevented.

Further, the idle state detecting means may detect that the opening of the throttle valve in the fuel supply device for the engine is equal to or less than the set idle opening. With this configuration, for example, a throttle opening sensor used for electronic control of the engine can be used, and engine overheating during idling can be prevented without complicating the configuration. Further, a throttle lever for operating the throttle opening may be provided on the steering wheel, and an idle switch for detecting that the operation of the throttle lever is equal to or less than the predetermined idle opening may be provided near the throttle lever. With this configuration, the idle state can be detected by the idle switch without providing the slot sensor. Means for outputting warning information (for example, an indicator lamp) when the small snowmobile is in a stopped state and the engine is in an idle state, before, during, or at least after execution of the stop control by the engine control unit. , Buzzer, etc.).
It is possible to reliably notify that the engine has been left idle.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1A is an overall explanatory view of a small snowmobile (snowmobile) applied to an embodiment of the present invention, FIG. 1B is an explanatory plan view of a heat exchanger, and FIG. 2 is cooling water of a water-cooled engine. FIG. 3 is an explanatory view of a circulation path, FIG. 3 is an explanatory view of a heat exchanger mounted on the small snowmobile, FIG. 4 is an explanatory view of an idle switch provided on a steering wheel, and FIG. 5 is an operation flowchart of an engine water cooling control device. FIG. The water-cooled engine according to the present invention can be applied to any type of engine such as two-cycle or four-cycle as long as it is a water-cooled engine.

In the small snowmobile according to the embodiment, a pair of left and right steering sleds 13 are directed (directed) below a front portion (engine mount frame) 11 of a vehicle body (body frame) 10 extending in the front-rear direction. It is installed so that it can rotate freely,
A driving crawler (trail) 16 for circulating the track belt 15 is disposed below the rear portion 12 of the vehicle body.
The crawler 16 includes a drive wheel 17 disposed at a front end (or a frame central portion) of a vehicle body rear portion 12, a vertical driving wheel 18 disposed at a rear end, a plurality of intermediate wheels 19, a suspension mechanism (not shown), and a wheel. A track belt 15 wrapped around and circulating is provided.

The vehicle body 10 is entirely formed of a monocoque frame structure including a vehicle body front portion 11 and a vehicle body rear portion 12. The front portion 11 of the vehicle body in which the water-cooled engine 2 is mounted in the internal engine room 14 is formed in a substantially ship bottom shape in which the upper opening of the internal engine room 14 can be opened and closed by the front cover 4. The water-cooled engine 2 is mainly supported by a main portion 11a of a front portion 11 of the vehicle body, and a front portion of the main portion 11a is formed to protrude upward to accommodate an upper portion of a front suspension 13a for supporting a steering sled 13. A suspension housing 11b is formed, and a track housing 11c that houses a portion above the driving wheel 17 of the crawler 16 is formed continuously and integrally with the vehicle body rear portion 12 in a shape in which a rear portion of the main portion 11a rises obliquely rearward and upward. Is formed.

The rear portion 12 of the vehicle body extends across the rear end in the front-rear direction of the vehicle body, and also serves as a cover for housing the entire crawler 16 therebelow. Further, a saddle-shaped seat 22 on which an occupant sits is disposed above the rear portion 12 of the vehicle body, and a step 23 for lowering the occupant, which is one step lower than the seat 22, is provided on both sides of the seat 22 in the vehicle width direction. Is provided. A steering shaft (not shown) is erected substantially at the center of the vehicle body between the seat 22 and the front cover 4, and a bar handle 2 is provided at an upper end of the steering shaft.
6 is extended leftward and rightward in a horizontal direction with a slight inclination.

A windshield 28 is erected in front of the bar handle 26, and the front bottom cover 4 is turned upside down from the base of the windshield 28 so that the front cover 4 gently descends forward in a substantially streamlined shape. It has a sparse shape. Further, the steering sled 13 is operated by the bar handle 26 via a steering shaft.

In a small snowmobile, the water-cooled engine 2 is provided in an engine room 14 at a front portion 11 of the vehicle body, and a rear portion 12 of the vehicle body 12 is provided below a seat 22 and above a crawler 16 (trail 15) for traveling. A heat exchanger 30 is provided along the lower surface of the cover, and cooling water is circulated through the heat exchanger 30 so that the cooling water is cooled by snow scavenged during traveling. This heat exchanger 3
Reference numeral 0 denotes a pipe having a horizontally long cross section, which is generally U-shaped in plan view and is deployed at the rear of the vehicle body, as shown in FIGS. In the embodiment, in addition to the substantially U-shaped heat exchanger 30 below the sheet 22, a flat heat exchanger 32 is provided on the track housing 11c.
It is arranged adjacent to and opposed to.

The cooling water path of the water-cooled engine 2 is
As shown in FIG. 2 (partially shown in FIG. 3), first, the cooling water sent from the water pump 34 flows into the cylinder block 2a of the engine 2 and flows out of the cylinder head 2b to the flow path A outside the engine 2. I do. This flow path A is directed to the heat exchanger 30 (including other heat exchangers 32), and the heat exchanger 3
From 0, it is connected to the first inlet 36a of the thermostat (valve) 36 through the flow path B. In addition, the second inlet 3 of the thermostat 36 from the flow path A via the bypass flow path C
6b. The flow path A is connected to the second inlet 36b through the oil cooler 38 by the flow path D. Further, the cylinder head 2b is connected to the second inlet 36b via the flow path E and the throttle body 40.

The thermostat 36 has an outlet connected to the water pump 34. When the temperature of the cooling water is low and is lower than the set temperature at which the warm-up operation is required, the first inlet 3 is provided.
When the cooling water temperature is equal to or higher than the set temperature, the first inlet 36a is opened. That is, when the cooling water temperature is lower than the set temperature, the first inlet 3 of the thermostat 36
The cooling water warmed by the water jacket of the engine 2 by closing 6a circulates in the engine water jacket through the bypass flow path C, the oil cooler 38A through the flow path D, and the throttle body 40 through the flow path E. And warm-up operation. On the other hand, when the cooling water temperature is equal to or higher than the set temperature, the cooling water heated by the water jacket of the engine 2 due to the opening of the first inlet 36a of the thermostat 36 flows into the heat exchanger 30 from the flow path A, and the heat exchanger 30 From the thermostat 36 flows into the water pump 34, and the water pump 34 flows through the water jacket of the engine to cool the engine 2, thereby performing a normal operation.

In the case of a small snowmobile, an automatic centrifugal clutch, in which the engine 2 provided on a driving force transmission mechanism from the engine 2 to the crawler 16 (track belt 15) opens / connects at a speed lower than or higher than a set speed, is provided. , Crankshaft sensor for detecting engine speed (crank angle sensor may be used)
42 are provided. In the automatic centrifugal clutch, the engine 2 transmits power at or above a set rotation speed at which a sufficient starting torque is generated.
Power is not transmitted. Therefore, if the crankshaft sensor detects that the rotation speed is less than the set rotation speed,
Thus, it can be seen that the vehicle speed of the small snowmobile is zero.

In the small snowmobile according to the embodiment, an idling state detecting section for detecting an idling operation state from the engine speed output from the crankshaft sensor 42 of the engine 2 and a running stop state from a vehicle speed sensor 44 of the snowmobile are detected. The engine control device includes a stop state detecting unit, a sensor 46 for detecting a cooling water temperature, and an engine control unit 48 capable of controlling stop of engine operation by ignition cut or fuel cut.

A throttle sensor 50 for detecting the opening of the throttle valve is provided as an idle state detecting section, and the idle state is detected by detecting that the opening of the throttle valve in the fuel supply device of the engine is equal to or less than the set idle opening. Can be detected. Further, a throttle switch 52 can be provided in addition to using the signal of the throttle sensor 50. For example, as shown in FIG. 4, a bar handle (steering handle) 26 is provided with a throttle lever 54 for operating a throttle opening, and an idle switch 52 for detecting that the operation of the throttle lever 54 is less than a predetermined idle opening. Can be provided near the throttle lever 54. In FIG. 4, the throttle lever 54 is pivotally mounted on a pivot shaft 54a at the base of the bar handle 26 grip 26a.
The idle switch 52 is in an on state in the throttle closed state in which the accelerator lever is made free as shown in (b), and the idle switch 52 is in an off state in the throttle open state in which the accelerator lever is gripped as shown in (b).

In the engine control device for a small snowmobile, the engine control unit 48 controls the engine under the conditions and procedures shown in FIG. First, it is determined whether or not the idle switch is on after the engine is started (step 1). Then, it is determined whether or not the engine speed corresponding to the vehicle stop condition in the released state of the automatic centrifugal clutch is equal to or lower than the idle speed (step 2). Next, it is determined whether the cooling water temperature is equal to or higher than the set overheating prevention water temperature (for example, 120 ° C.) (step 3). It is determined whether or not the time during which all of the conditions of Steps 1 to 3 are satisfied has continued for a set time (Step 4). If the set time has continued, it is determined that there is a possibility of overheating in an idle state, and a warning light or a warning is issued. The buzzer is activated (step 5). Then, ignition cut or fuel cut control of the engine 2 is performed to stop the engine 2 (step 6). When the snowmobile is in a stopped state and the engine is in an idle state, warning information such as a warning or a buzzer is output before, during or at least after the execution of the stop control by the engine control unit 48. You may do it.

The embodiment has the following operations and effects from the above configuration. Generally, in a small snowmobile with a water-cooled engine, the snow raked by the trail cools the cooling water circulating in the heat exchanger, and the snow cannot be lifted from the trail when the small snowmobile is stopped and idling. Therefore, the cooling water in the heat exchanger is not cooled, and if it is left as it is, the engine water temperature becomes too high, and the possibility of overheating occurs. On the other hand, according to the embodiment, as shown in FIG. 5, the engine control unit 48 determines that the snowmobile is in the stopped state, the engine is in the idle state, and the cooling water temperature is equal to or higher than the set temperature. Since the engine stop control is performed on condition that the engine continues for a set time or more, it is possible to reliably prevent engine overheating even when the snowmobile is stopped and the engine is idle.

The above-mentioned stopped state of the snowmobile can be dealt with by detecting the speed 0 by the vehicle speed sensor. However, even when the vehicle speed sensor is not provided, the following configuration can be used. That is, the automatic clutch is an automatic clutch in which the engine disposed on the driving force transmission mechanism from the engine of the small snowmobile to the trail is released / connected at a speed lower than or higher than the set speed, and the engine speed is detected by the crankshaft sensor. The stop state can be detected by detecting the stop state of the snowmobile on the condition that the detected engine speed is lower than the set speed of the automatic clutch release. With this configuration, there is no need to provide a vehicle speed sensor, and the existing automatic clutch means and engine speed detection means can be used in a small snowmobile. Can be prevented.

Further, the idle state can be detected by detecting that the opening of the throttle valve in the fuel supply device of the engine is equal to or less than the set idle opening.
With this configuration, for example, a throttle opening sensor used for electronic control of the engine can be used, and engine overheating during idling can be prevented without complicating the configuration. Further, a throttle lever 54 for operating the throttle opening is provided on the steering handle 26, and an idle switch 52 for detecting that the operation of the throttle lever 54 is equal to or less than a predetermined idle opening is provided near the throttle lever 54. In this way, the idle state can be detected by the idle switch 52 without detecting the idle state by the slot sensor.

[0027]

As described above, according to the present invention, the fact that the snowmobile is in the stopped state, the engine is in the idle state, and the fact that the cooling water temperature is higher than the set temperature has continued for the set time or longer. Since the engine is controlled to stop according to the conditions, the engine can be reliably prevented from overheating even when the snowmobile is stopped and the engine is idle.

[Brief description of the drawings]

FIG. 1A is an overall explanatory view of a small snowmobile (snowmobile) applied to an embodiment of the present invention, and FIG. 1B is an explanatory plan view of a heat exchanger.

FIG. 2 is an explanatory diagram of a circulation path of cooling water of a water-cooled engine.

FIG. 3 is an explanatory diagram of a heat exchanger mounted on a small snowmobile.

FIGS. 4A and 4B are explanatory diagrams of an idle switch provided on a steering wheel, wherein FIG. 4A shows an idle switch on state, and FIG. 4B shows an idle switch off state.

FIG. 5 is an operation flowchart of the engine water cooling control device.

[Explanation of symbols]

 2 Engine 16 Crawler 30 Heat exchanger 32 (flat) heat exchanger 36 Thermostat 38 Oil cooler 42 Crankshaft sensor 48 Engine control unit 50 Throttle sensor 52 Idle switch 54 Throttle lever

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 35/00 364 F02D 35/00 364R 41/22 330 41/22 330D F02P 11/02 304 F02P 11/02 304Z 11/04 302 11/04 302B F term (reference) 3D037 FA23 FA24 FB05 FB09 FB10 FB12 3G019 AA10 AC03 CB17 CB18 GA05 GA09 GA11 GA18 3G084 AA06 BA13 BA16 BA33 CA03 CA07 DA37 EA07 EA11 EB22 FA03 FA04 FA03 FA04 CA12 DA01 DA05 DA06 DB05 EA05 EA12 3G301 HA01 HA28 JA32 KA07 KA26 KA28 MA11 MA24 NE23 PA11Z PA14Z PE01Z PE08Z PF01Z

Claims (5)

[Claims] 1. A water-cooled engine is provided in an engine room at a front part of a vehicle body, and a heat exchanger is provided above a traveling trail at a rear part of the vehicle body. Cooling water is circulated through the heat exchanger to scrape the trail during traveling. In a small snowmobile equipped with a water-cooled engine in which the cooling water is cooled by the lifted snow, idle state detection means for detecting an idle operation state of the engine, and stop state detection for detecting a traveling stop state of the small snowmobile Means, a coolant temperature detecting means, and an engine control unit capable of controlling engine operation to be stopped by ignition cut or fuel cut. The engine control unit is configured to operate when the small snowmobile is stopped and when the engine is idle. That the cooling water temperature is higher than the set temperature for more than the set time. Small snowmobile engine control apparatus, characterized in that the stop control of the engine on condition that it has. 2. An automatic clutch means for disengaging / connecting the engine at a speed lower than or higher than a set speed, and a means for detecting the engine speed, provided on a driving force transmission mechanism from the engine of the small snowmobile to the trail. The stop state detecting means detects the stop state of the snowmobile on the condition that the detected engine speed is less than the set speed of the automatic clutch means release. Engine control device for small snowmobiles. 3. The engine according to claim 1, wherein the idle state detecting means detects that the opening of the throttle valve in the fuel supply device of the engine is equal to or less than a set idle opening. Engine control device for small snowmobiles. 4. A throttle lever for operating a throttle opening is provided on a steering handle, and an idle switch for detecting that the operation of the throttle lever is equal to or less than a predetermined idle opening is provided near the throttle lever. The engine control device for a small snowmobile according to claim 1 or 2. 5. A means for outputting warning information when the snowmobile is in a stopped state and the engine is in an idle state, at least before, during or after execution of the stop control by the engine control unit. The engine control device for a small snowmobile according to any one of claims 1 to 4, wherein: