JP2006097501A - Dry running prevention device of water pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry running prevention device of a water pump capable of preventing the water pump from being raced without complicating the assembling operation of an engine with the water pump. <P>SOLUTION: An engine output occurrence rate OPrate is estimated based on an engine rotational speed NE and a throttle opening θTH (S12), and it is determined whether the estimated output occurrence rate OPrate is lower than a prescribed value #OP rate or not (S14). When the output occurrence rate OPrate is equal to or lower than the prescribed value #OPrate, the water pump is determined to be raced and the operation of the engine is stopped (S18). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an idling prevention device for a water pump.

  Conventionally, a so-called engine pump in which a water pump is driven by an engine is widely known. Many water pumps use self-primed water to cool the heat generating part, and if idling (empty pumping) continues, there is a risk of causing seizure or poor sealing.

Therefore, a technique for preventing the idling of the water pump has been conventionally proposed. For example, in the technique described in Patent Document 1, a float type or pressure type switch for detecting the water level is provided in the casing of the water pump, and it is detected that the water level in the casing is less than a predetermined value. The operation of the engine that drives the water pump is stopped.
Japanese Patent Laid-Open No. 56-118591 (lower left column on page 2, line 7 to line 14 etc.)

  However, when the switch for detecting the water level is provided inside the water pump as described above and the operation of the engine is stopped based on the output, the water pump and the engine are electrically connected by a signal line or the like. There is a problem that the assembly work of the engine and the water pump becomes complicated.

  Accordingly, an object of the present invention is to solve the above-described problem, and to provide a water pump idling prevention device that prevents idling of the water pump without complicating the assembly work of the engine and the water pump. There is.

  In order to solve the above-described problem, according to claim 1, in a water pump anti-spinning device for preventing idling of a water pump driven by an engine, output of the engine is generated based on an operating state of the engine. Output generation rate estimation means for estimating the rate, and operation stop means for stopping the operation of the engine when the estimated output generation rate is equal to or less than a predetermined value.

  According to a second aspect of the present invention, the operation stopping means is configured to stop the operation of the engine when the estimated output occurrence rate continues for a predetermined time and is equal to or less than the predetermined value.

  According to a third aspect of the present invention, the actuator further opens and closes the throttle valve of the engine, the engine speed detecting means for detecting the engine speed, and the throttle opening for detecting the throttle valve opening. Detecting means, and actuator control means for controlling the drive of the actuator based on the detected engine speed and throttle opening, and opening and closing the throttle valve to adjust the output of the engine, and the output The occurrence rate estimation means is configured to estimate the output occurrence rate using the detected engine speed and throttle opening as the operating state of the engine.

  In the idling prevention device for the water pump according to claim 1, the output occurrence rate estimating means for estimating the output occurrence rate based on the operating state of the engine, and when the estimated output occurrence rate is equal to or less than a predetermined value, Since the engine is provided with an operation stop means for stopping the operation of the engine, the detection of the idling of the water pump (specifically, the decrease in engine output accompanying the decrease in the load caused by the idling of the water pump) and the engine Therefore, it is not necessary to provide a switch or a sensor for detecting the water level in the water pump, and thus it is not necessary to electrically connect the engine and the water pump. Therefore, idling of the water pump can be prevented without complicating the assembly work of the engine and the water pump.

  Further, since the prevention of idling of the water pump can be performed only on the engine side, the versatility of the apparatus is high, and therefore the labor and cost when replacing the water pump or adding a product lineup can be reduced.

  In this specification, “water” is used to include all liquids that can be pumped up, such as seawater and muddy water, in addition to fresh water. Accordingly, the “water pump” means a pump used for pumping various liquids such as seawater and muddy water in addition to fresh water.

  Further, in the idling prevention device for the water pump according to claim 2, the operation stopping means stops the operation of the engine when the estimated output occurrence rate continues for a predetermined time and is not more than a predetermined value. Since it comprised, in addition to an above-described effect, it can prevent that an engine driving | operation is stopped by the idling for a short time which does not become a problem on durability of a water pump, Therefore Workability | operativity can be improved.

  In the idling prevention device for a water pump according to claim 3, an actuator for opening and closing an engine throttle valve, an engine speed detecting means for detecting the engine speed, and an opening of the throttle valve. Throttle opening detecting means for detecting the degree, and actuator control means for controlling driving of the actuator based on the detected engine speed and throttle opening, and adjusting the output of the engine by opening and closing the throttle valve The output generation rate estimating means is configured to estimate the output generation rate using the detected engine speed and throttle opening as the engine operating state, in other words, the engine throttle The device is equipped with an electronically controlled throttle device (so-called electronic governor) and Since the output generation rate is estimated based on the engine speed and the throttle opening, which are parameters necessary for operating the electronically controlled throttle device, a switch for detecting the idling of the water pump, There is no need to provide a new sensor, and thus the above-described effects can be obtained with a simple configuration.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out a water pump anti-skid device according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a front view of an engine pump unit in which an anti-spinning device for a water pump according to a first embodiment of the present invention is mounted. FIG. 2 is a plan view of the engine pump unit shown in FIG.

  1 and 2, reference numeral 10 indicates an engine pump unit. The engine pump unit 10 includes an engine 12 and a water pump 14 driven by the engine 12. The engine 12 and the water pump 14 are mounted on a pipe-shaped frame 16. The engine 12 includes a recoil starter 18 and can be started by an operator operating it.

  Specifically, the water pump 14 is a spiral pump, and includes an inlet pipe 20 that is a water inlet and an outlet pipe 22 that is a outlet. The inlet pipe 20 is connected to a water supply source such as a water storage tank through a hose or a pipe (not shown). On the other hand, the outlet pipe 22 is connected to a water supply destination through a hose or a pipe (not shown). Water sucked into the water pump 14 from the inlet pipe 20 is discharged from the outlet pipe 22.

  FIG. 3 is an explanatory sectional view of the engine 12.

  The engine 12 includes one cylinder (cylinder) 30, and a piston 32 is accommodated therein so as to freely reciprocate. An intake valve 36 and an exhaust valve 38 are disposed at a position facing the combustion chamber 34 of the engine 12, and opens and closes between the combustion chamber 34 and the intake pipe 40 or the exhaust pipe 42. The engine 12 is specifically a water-cooled four-cycle single-cylinder OHV type internal combustion engine, and has a displacement of 163 cc.

  The piston 32 is connected to a crankshaft 44, and the crankshaft 44 is connected to a camshaft 46 through a gear. A flywheel 48 is attached to one end of the crankshaft 44, and the recoil starter 18 is attached to the tip end side of the flywheel 48. On the other hand, an impeller (described later) of the water pump 14 is attached to the other end of the crankshaft 44.

  A power generation coil (alternator) 50 is disposed inside the flywheel 48 to generate an alternating current. The alternating current generated by the power generation coil 50 is converted into a direct current through a processing circuit (not shown), and then supplied as an operating power source to an ECU (described later), an ignition circuit (not shown), or the like.

  A throttle body 52 is disposed in the middle of the intake passage 40. A throttle valve 54 is accommodated in the throttle body 52, and the throttle valve 54 is connected to an electric motor 56 (actuator, specifically a stepping motor) via a throttle shaft and a reduction gear mechanism (both not shown). Further, a carburetor assembly 58 (shown in FIG. 1) is attached upstream of the throttle valve 54 in the throttle body 52.

  The carburetor assembly 58 is connected to a fuel tank 60 (shown in FIGS. 1 and 2) and injects gasoline fuel into the intake air in accordance with the opening of the throttle valve 54 to generate an air-fuel mixture. The generated air-fuel mixture is sucked into the combustion chamber 34 of the cylinder 30 through the throttle valve 54, the intake passage 40 and the intake valve 36.

  A throttle opening sensor 62 is disposed in the vicinity of the electric motor 56 and outputs a signal corresponding to the opening θTH of the throttle valve 54 (hereinafter referred to as “throttle opening”). A crank angle sensor 64 made of an electromagnetic pickup is disposed near the flywheel 48 and outputs a pulse signal at every predetermined crank angle.

  Outputs of the throttle opening sensor 62 and the crank angle sensor 64 are input to an ECU (electronic control unit) 66. The ECU 66 includes a microcomputer including a CPU, a ROM, a RAM, and a counter, and is disposed at an appropriate position of the engine pump unit 10.

  The ECU 66 counts the output pulses of the crank angle sensor 64 and detects (calculates) the engine speed NE. Further, the ECU 66 sets and sets the target throttle opening so that the engine rotation speed NE matches the target rotation speed (for example, 3000 [rpm]) based on the detected engine rotation speed NE and the throttle opening θTH. An energization command value corresponding to the target throttle opening is output to the electric motor 56 to control its drive.

  As described above, the engine 12 has the throttle valve 54 opened and closed by the electronically controlled throttle device (electronic governor) including the electric motor 56, the throttle opening sensor 62, the crank angle sensor 64, and the ECU 66, and its output is adjusted. .

  Next, the structure of the water pump 14 will be described.

  FIG. 4 is an exploded perspective view of the water pump 14.

  As shown in FIG. 4, the water pump 14 includes a casing 70. An opening 72 is formed in the side surface of the casing 70, and the inlet pipe 20 is fixed to the opening 72 by a plurality of bolts 74 (only one is shown in the figure). A packing 76 is inserted in a contact portion between the casing 70 and the inlet pipe 20. An inlet valve 80 is attached to the inlet pipe 20 by a plurality of bolts 82 (only one is shown in the figure). In FIG. 4 and FIG. 5 to be described later, a washer, a shim, an O-ring, etc. used when fastening bolts and nuts are not shown.

  An opening 84 is formed in the upper surface of the casing 70, and the outlet pipe 22 is fixed to the opening 84 by a plurality of bolts 86 (only one is shown in the figure). A packing 88 is inserted in a contact portion between the casing 70 and the outlet pipe 22.

  An opening 90 is drilled at an appropriate position of the outlet pipe 22. The opening 90 is a so-called priming water inlet that is required when the water pump 14 is started, and is sealed by a filler cap 92 that is detachable by an operator.

  Further, the entire surface of the casing 70 facing the opening 72 is opened, and a casing cover 96 is attached thereto by a plurality of bolts 98 (only one is shown in the figure). A seal ring 100 is inserted in a contact portion between the casing 70 and the casing cover 96.

  FIG. 5 is an exploded perspective view of the casing cover 96.

  As shown in FIG. 5, the casing cover 96 is attached to the engine 12 by a plurality of bolts 102 (only one is shown in the figure). Further, a vortex chamber 106 is formed on the surface of the casing cover 96 facing the casing 70 (not shown in FIG. 5) by a wall portion 104 protruding in a spiral shape. Specifically, the vortex chamber 106 has a shape that reaches the discharge port 108 formed in the upper portion while the passage cross-sectional area is enlarged counterclockwise on the paper surface.

  An impeller 110 is accommodated in the vortex chamber 106. Further, a through hole 112 is formed in the casing cover 96, and the crankshaft 44 of the engine 12 is inserted into the vortex chamber 106 through the through hole 112. The impeller 110 is fixed by a nut 114 while being positioned by a key (not shown) on the crankshaft 44 inserted through the vortex chamber 106. The rotation direction of the crankshaft 44 and the impeller 110 is counterclockwise on the paper surface. Reference numeral 120 denotes a mechanical seal attached to the outer periphery of the crankshaft 44, and reference numeral 122 denotes a seal collar fitted into the through hole 112 together with the mechanical seal 120.

  A friction disk 126 is attached to the wall portion 104 by a plurality of bolts 124 (one is shown in FIG. 5 and only two are shown in FIG. 4). Thereby, the vortex chamber 106 is sealed. A through hole 128 is formed in the friction disk 126, and the through hole 128 is communicated with an opening 72 formed in the casing 70 via a seal ring 130 (shown in FIG. 4).

  Here, the flow of water sucked into the water pump 14 will be described with reference to FIGS. 4 and 5. When the engine 12 is operated and the crankshaft 44 and the impeller 110 are rotated counterclockwise on the paper surface, a suction force is generated and water is sucked from the inlet pipe 20. The water sucked from the inlet pipe 20 passes through the opening 72 formed in the casing 70 and the through hole 128 formed in the friction disk 126 and flows into the vortex chamber 106.

  The water that has flowed into the vortex chamber 106 is pumped to the discharge port 108 of the vortex chamber 106 by the rotation of the impeller 110, passes through the opening 84 formed in the casing 70, and passes through the outlet pipe 22 to the outside. Discharged.

  Next, the operation of the idling prevention device for the water pump according to this embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing the operation. The illustrated program is executed in the ECU 66 every predetermined cycle (for example, 20 [msec]).

  Before continuing the description of the flowchart of FIG. 6, the outline of the operation will be described first with reference to FIG. FIG. 7 is a characteristic diagram showing the characteristics of the output OP of the engine 12 with respect to the engine speed NE.

  When the water pump 14 is idling (pumping), the engine output OP is significantly reduced as the load decreases. Specifically, as shown in FIG. 7 as an example when the engine speed NE is 3000 [rpm], the engine output OP when the water pump 14 idles is 10 [%] of the fully open output OPmax. Decrease to a degree. Therefore, by determining the output occurrence rate (referred to as “OPrate”) of the engine 12, it is possible to detect idling of the water pump 14 based on the value.

  The fully-open output OPmax is a value obtained by experimenting the maximum output that can be generated by the engine 12 for each engine speed NE, and the output generation rate OPrate is the engine output OP and the engine speed NE at that time. Is a value obtained by dividing by the fully open output OPmax corresponding to.

  Here, the output occurrence rate OPrate of the engine 12 can be estimated from the operating state of the engine 12.

  FIG. 8 is a characteristic diagram showing the characteristics of the output occurrence rate OPrate with respect to the throttle opening θTH when the engine speed NE is 3000 [rpm].

  As shown in FIG. 8, the output occurrence rate OPrate can be uniquely determined by the throttle opening θTH when the engine speed NE is determined. That is, the output generation rate OPrate can be estimated by using the engine speed NE and the throttle opening degree θTH as the operating state of the engine 12 described above.

  Therefore, in this embodiment, the characteristics of the output occurrence rate OPrate with respect to the throttle opening degree θTH as shown in FIG. 8 are mapped for each engine speed NE, and the engine speed NE and the throttle opening degree θTH are detected. The output occurrence rate OPrate is estimated by searching the map based on the value. Then, by determining whether the estimated output occurrence rate OPrate is equal to or less than a predetermined value, it is determined whether or not the engine output OP has significantly decreased, so that idling of the water pump 14 is detected. Note that the engine speed NE and the throttle opening θTH used for estimating the output generation rate OPrate are also parameters necessary for operating the electronically controlled throttle device (electronic governor) described above.

  6 will be described based on the above assumption. First, in S10, the engine speed NE and the throttle opening θTH are detected. Next, in S12, the output occurrence rate OPrate is estimated based on the detected engine speed NE and the throttle opening θTH.

  Next, in S14, it is determined whether or not the output occurrence rate OPrate is equal to or less than a predetermined value #OPrate (for example, 10 [%]), in other words, whether or not the water pump 14 is idling. For example, as shown in FIG. 8, if the throttle opening degree θTH is 12 [degrees] or less when the engine speed NE is 3000 [rpm], the output generation rate OPrate is a predetermined value #OPrate (10 [%]). From the following, it is determined that the water pump 14 is idling.

  When the result in S14 is negative, that is, when it is determined that the engine output OP has not significantly decreased and the water pump 14 is not idling, the subsequent processing is skipped. On the other hand, when the result in S14 is affirmative, that is, when it is determined that the engine output OP has significantly decreased and the water pump 14 is idling, the process proceeds to S16, where the output rate OPrate is set for a predetermined time (for example, 3 [sec]) It is continuously determined whether or not it is equal to or less than a predetermined value #OPrate.

  When the result in S16 is affirmative, the program proceeds to S18, in which the engine 12 is cut off to stop its operation, and thus the water pump 14 is stopped. If the result in S16 is negative, the process of S18 is skipped, and in a program (not shown), a process such as incrementing a counter that counts the elapsed time after the output occurrence rate OPrate becomes equal to or less than the predetermined value #OPrate is performed. Do. The determination in S16 is made by referring to the value of the counter.

  As described above, in the idling prevention device for the water pump according to this embodiment, the output generation rate OPrate of the engine 12 is estimated based on the operating state of the engine 12, and the estimated output generation rate OPrate is a predetermined value #OPrate. When it is below, it is determined that the water pump 14 is idling and the operation of the engine 12 is stopped. Therefore, idling of the water pump 14 can be prevented.

  Further, both detection of idling of the water pump 14 (specifically, reduction of the engine output OP due to a decrease in load caused by idling of the water pump 14) and stop of the operation of the engine 12 are executed on the engine side. Therefore, it is not necessary to provide the water pump 14 with a switch or a sensor for detecting the water level, and thus it is not necessary to electrically connect the engine 12 and the water pump 14. Therefore, idling of the water pump 14 can be prevented without complicating the assembly work of the engine 12 and the water pump 14.

  Furthermore, since the prevention of idling of the water pump can be performed only on the engine side, the versatility of the apparatus is high, and therefore the labor and cost when replacing the water pump or adding a product lineup can be reduced.

  In addition, since the operation of the engine 12 is stopped when the estimated output occurrence rate OPrate is continuously equal to or less than the predetermined value #OPrate for a predetermined time, the idling of the water pump 14 does not cause a problem in durability for a short time. It is possible to prevent the operation of the engine 12 from being stopped, thereby improving workability.

  Further, as a throttle device of the engine 12, an electronically controlled throttle device (so-called electronic governor) that drives a throttle valve 54 by an electric motor 56 is provided, and parameters necessary for operating the electronically controlled throttle device are provided. Since the output generation rate OPrate is estimated based on a certain engine speed NE and the throttle opening θTH, there is no need to newly provide a switch or a sensor for detecting idling of the water pump 14, and thus a simple configuration The above effects can be obtained.

  As described above, in the first embodiment of the present invention, in the idling prevention device for the water pump that prevents the idling of the water pump (14) driven by the engine (12), the operating state of the engine (12) Output rate estimation means (ECU 66, S12 in the flowchart of FIG. 6) for estimating the output rate (OPrate) of the engine (12) based on the above, and the estimated output rate (OPrate) is a predetermined value (#OPrate) ) It is configured to include operation stop means (ECU 66, S14 and S18 in the flowchart of FIG. 6) for stopping the operation of the engine (12) when:

  Further, the operation stopping means stops the operation of the engine when the estimated output occurrence rate (OPrate) is not more than the predetermined value (#OPrate) continuously for a predetermined time (S14 in the flowchart of FIG. 6). S16, S18).

  Furthermore, an actuator (electric motor 56) for opening and closing the throttle valve (54) of the engine (12), and an engine speed detecting means (crank angle sensor 64) for detecting the speed (NE) of the engine (12) , Throttle opening detection means (throttle opening sensor 62) for detecting the opening of the throttle valve (54), and the actuator (NE) and the throttle opening (θTH) based on the detected engine speed (NE) and the throttle opening (θTH). 56) and an actuator control means (ECU 66) for adjusting the output of the engine (12) by opening and closing the throttle valve (54) and controlling the output of the engine ( 12) Using the detected engine speed (NE) and throttle opening (θTH) as the operating state of 12) The output generation rate (OPrate) is estimated.

  In the above description, the water pump 14 is a spiral pump, but other types of pumps may be used.

  Moreover, the predetermined value #OPrate, which is a threshold value when detecting idling of the water pump 14, is a value that should be appropriately set according to the characteristics of the water pump 14 and the engine 12, and is limited to the above 10%. Is not to be done.

  Further, although the stepping motor is used as the actuator for opening and closing the throttle valve 54, other actuators such as a DC motor and a rotary solenoid may be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of an engine pump unit on which a water pump idling prevention device according to a first embodiment of the present invention is mounted. It is a top view of the engine pump unit shown in FIG. FIG. 2 is an explanatory sectional view of the engine shown in FIG. 1. It is a disassembled perspective view of the water pump shown in FIG. It is a disassembled perspective view of the casing cover shown in FIG. It is a flowchart which shows operation | movement of the idling prevention apparatus of a water pump performed by ECU shown in FIG. FIG. 4 is a characteristic diagram illustrating output characteristics with respect to a rotational speed of the engine illustrated in FIG. 3. FIG. 7 is a characteristic diagram showing a characteristic of an engine output occurrence rate with respect to a throttle opening, which is used in the processing of the flowchart of FIG. 6.

Explanation of symbols

12 Engine 14 Water pump 54 Throttle valve 56 Electric motor (actuator)
62 Throttle opening sensor (throttle opening detection means)
64 Crank angle sensor (engine speed detection means)
66 ECU (output generation rate estimation means, operation stop means)

Claims (3)

  In a water pump idling prevention device for preventing idling of a water pump driven by an engine, output rate estimating means for estimating an output rate of the engine based on an operating state of the engine, and the estimated output generation An idling prevention device for a water pump, comprising: an operation stop means for stopping the operation of the engine when the rate is equal to or less than a predetermined value.   2. The idling prevention device for a water pump according to claim 1, wherein the operation stopping unit stops the operation of the engine when the estimated output occurrence rate continues for a predetermined time and is equal to or less than the predetermined value. . Furthermore, an actuator for opening and closing the throttle valve of the engine, an engine speed detecting means for detecting the engine speed, a throttle opening detecting means for detecting the opening of the throttle valve, and the detected engine speed Actuator control means for controlling the drive of the actuator based on the number and throttle opening, and opening and closing the throttle valve to adjust the output of the engine, and the output occurrence rate estimating means for operating the engine 3. The water pump anti-skid device according to claim 1, wherein the output generation rate is estimated using the detected engine speed and throttle opening as a state.

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