JPH0589818U - Lubricator for 2-cycle engine - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the cost of a lubrication device for a two-cycle engine that controls the amount of oil supplied to the engine by computer control of the opening time of the solenoid valve. [Constitution] The conduction time between the upstream side of the check valve arranged in the discharge side oil passage of the oil pump and the passage for returning a part of the oil discharged from the oil pump to the oil tank or the suction side of the oil pump is set. Computer controlled using a normally closed 2-port solenoid valve.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a two-cycle engine separate lubrication apparatus, and more particularly to a computer-controlled two-cycle engine lubrication apparatus that appropriately controls an oil supply amount in accordance with engine operating conditions.

[0002]

[Prior Art]

 Separate lubrication of a two-cycle engine for vehicles is performed by a driving worm driven by the engine's rotating shaft, in which the plunger reciprocates along with rotational movement to perform pumping action, and a throttle valve arranged in the intake passage of the engine. It started with a mechanical oil pump in which the stroke of the plunger is controlled in conjunction with the opening of the engine, and the oil supply amount is controlled in relation to the engine speed and the opening of the throttle valve. Since the oil supply amount does not depend only on the engine speed and the opening of the throttle valve, the oil supply amount is calculated by the computer that inputs the output of the sensor that detects engine operating conditions and calculates the required oil supply amount. Electronically controlled lubrication devices have been proposed.

FIG. 5, FIG. 6 and FIG. 7 show the structure of an electronically controlled lubricating device disclosed in Japanese Patent Laid-Open No. 2-191807. In each drawing, reference numeral 1 is an oil tank, 2 is a solenoid valve, 3 is an oil pump, 4 is an engine, 5 is a computer for inputting the output of a sensor for detecting the operating condition of the engine, and calculating a required oil supply amount, 6 is a check valve.

In the configuration shown in FIG. 5, a normally open two-port solenoid valve 2 (which simply shuts off the oil passage) is arranged on the suction side of the oil pump 3, and the suction-side oil passage is shut off by the output of the computer 5. The amount of oil supplied to the engine 4 is controlled according to the duration of time.

In the configuration of FIG. 6, a 3-port solenoid valve 2 is arranged on the discharge side of the oil pump 3, on the engine side when not energized, and on the suction side of the oil pump 3 when energized. The amount of oil supplied to the engine 4 is controlled by the time for returning the oil discharged from the oil pump 3 to the suction side of the oil pump 3.

In the configuration of FIG. 7, a normally open two-port solenoid valve 2 is arranged between the oil pump 3 and the engine 4, and the space between the solenoid valve 2 and the oil pump 3 is connected to the suction side of the oil pump 3. However, when the solenoid valve 2 is closed by the output of the computer 5 by forming an oil return passage in which a check valve 6 that opens toward the suction side is arranged, the supply of oil to the engine 4 is cut off. The oil discharged from the oil pump 3 opens the check valve 6 and returns to the suction side, and the output of the computer 5 controls the time during which the solenoid valve 2 is closed to control the oil supply amount to the engine 4. Is.

Therefore, in the configuration of FIG. 5 in which the suction side of the oil pump 3 is electrically connected and cut off, the negative pressure generated on the suction side causes a variation in the discharge amount of oil, which results in an accurate oil supply amount to the engine. Since the control becomes difficult, and in the configurations of FIGS. 6 and 7, no significant pressure fluctuation occurs on the suction side or the discharge side of the oil pump 3 due to switching or shutting off by the solenoid valve 2, and therefore the accuracy of the oil supply amount to the engine However, in the configuration of FIG. 6, the 3-port solenoid valve causes a cost increase, and in the configuration of FIG. 7, the check valve 6 arranged in the oil return passage causes a cost increase. On the other hand, in a lubrication system for a two-cycle engine, a check valve is generally arranged on the discharge side of the oil pump in order to prevent the backflow tendency of the oil due to the engine back pressure.

[0008]

[Problems to be solved by the device]

 By utilizing a check valve that is generally arranged on the discharge side of an oil pump, it is possible to obtain a lubrication device for an electronically controlled two-cycle engine at a lower cost than the configuration shown in FIG. 6 or 7. However, this is the subject of the present invention.

[0009]

[Means for Solving the Problems]

 The above problems can be solved by the following configurations. That is, in a lubrication device for a two-cycle engine that uses an oil pump driven by a rotary shaft of an engine, in which a check valve is arranged in the oil passage on the discharge side of the oil pump, An oil return passage for returning a part of the oil discharged by the oil pump to the oil tank or the oil pump suction side is opened on the upstream side of the check valve, and is connected to the oil return passage or the discharge side oil passage of the return passage. The normally-closed 2-port solenoid valve that opens by the output of the computer that inputs the sensor output that detects the engine operating condition and calculates the oil supply amount to the engine is installed in the opening.

[0010]

[Action]

 By controlling the opening period of the normally closed 2-port solenoid valve, the amount of oil discharged from the oil pump returning to the oil tank or the suction side of the oil pump is controlled, and the amount supplied to the engine via the check valve is controlled. Control according to engine operating conditions. The operation will be described with reference to FIG. 1. Reference numeral 1 is an oil tank, 2 is a normally closed 2-port solenoid valve, 3 is an oil pump, 4 is a 2-cycle engine, 5 is a computer, and 6 is a check valve. In addition to the same cases as in FIGS. 5, 6, and 7, 7 is an oil return passage, 8 is a sensor output for sensing engine operating conditions, 9 is a computer output, and a normally closed 2-port solenoid valve 2 Is closed, the oil pump 3 inhales and discharges the oil from the oil tank 1, opens the check valve 6 by the pressure and flows into the engine 4, and the output of the sensor that senses the engine operating condition. When the solenoid valve 2 is opened by the output 9 of the computer 5 which inputs 8 to calculate the required oil supply amount, the oil passes through the oil return passage 7 and is sucked into the oil tank 1 or the oil pump 3. Returned to the side. The amount of oil obtained by subtracting the amount of oil returned from the oil pump 3 by the valve opening time of the solenoid valve 2 is supplied to the engine 4, and the amount of oil supplied to the engine is controlled by controlling the valve opening time. The check valve 6 is a check valve generally used in a lubrication device of a two-cycle engine, and is not particularly arranged because the oil supply amount to the engine is electronically controlled.

An oil passage extending from the oil pump 3 to the check valve 6 and an oil return passage 7 extending from the oil passage to the solenoid valve 2 are connected to the pipe connecting the oil pump 3 and the check valve 6, respectively. It may be a pipe that connects the pipe and the solenoid valve 2, but changes in the internal volume of the pipe due to expansion and contraction of the pipe due to fluctuations in the oil pressure due to opening and closing of the solenoid valve 2 or air contained in the oil. Since the oil supply amount to the engine may change due to a change in the volume of the oil pump, the check valve 6 and the solenoid valve 2 are integrally assembled in the casing of the oil pump 3, and the oil pump 3 reaches the check valve 6. If the oil passage and the oil return passage extending from the passage to the solenoid valve 2 are formed in the casing of the oil pump 3, the rigidity of the casing of the oil pump 3 eliminates the change in the internal volume of the two passages. The decrease in the amount of oil in the inside also reduces the volume change of the air in the oil, and the control accuracy of the amount of oil supplied to the engine is improved (claim 2).

[0012]

【Example】

 Fig. 2 shows an example of the present invention in which a mechanical oil pump having a plunger that reciprocates with rotary motion is used as an oil pump, and a check valve and a 2-port solenoid valve are integrally attached to the casing of the oil pump. FIG. 3 is a sectional view of the first embodiment, FIG. 3 is a sectional view taken along the line AA of FIG. 2, and the reference numerals 1 to 8 in FIGS. 2 and 3 are the same as the reference numerals in FIG. In addition, 301 is a pump casing, 302 is a driving worm driven by the rotating shaft of the engine 4, 303 is a plunger, and the plunger 303 is a worm wheel 304 formed on the outer peripheral surface of the driving worm. The lead cam 305 formed on one end face engages with the plunger 303 to rotate in a cylinder formed in the housing 301, and protrudes into the cylinder in a direction perpendicular to the plunger 303. Was in contact with the Puraja guide shaft 306, reciprocates with the rotation movement. A sub-cylinder 307 is bored at the end of the plunger 303 opposite to the side on which the lead cam 305 is formed, and a sub-plunger 308 is arranged. A spring 309 biases the sub-plunger 308 against the inner surface of the lid 310 of the cylinder and the plunger 303 in the direction of abutting against the plunger guide shaft 306. The sub-cylinder 307 and the sub-plunger 308 form a pump action chamber 311. In the pump action chamber 311, an oil suction side passage 312 and an oil discharge side passage 313 formed in the plunger 303 are formed. Are in communication.

Reference numeral 314 denotes an oil passage on the suction side that communicates with the oil tank 1. The oil flowing from the oil passage 314 lubricates the contact surface between the lead cam 305 and the plunger guide shaft 306, and the driving worm 302 and the driving worm 302. After lubricating the meshing surface with the worm wheel 304, it is guided to the suction port 315 (shown by the broken line) opening to the cylinder. 316 is an oil passage on the discharge side, which opens to the cylinder to form a discharge port 317. When the oil suction passage 312 bored in the plunger 303 is electrically connected to the suction port 315 and the plunger 303 moves to the right in FIG. 3, the oil flows into the pump action chamber 311 and the oil bored in the plunger 303. When the discharge passage 313 communicates with the discharge port 317 and the plunger 303 moves to the left in FIG. 3, oil is pushed out from the pump action chamber 311 and a pump action is performed.

When a mechanical oil pump is used as the oil pump 3, the amount of oil discharged by the oil pump 3 is proportional to the rotational speed of the engine, so the opening degree of the throttle valve arranged in the intake passage of the engine 4 is The oil pump 3 is formed so as to give the maximum required oil discharge amount for each rotation speed of the engine 4 when the engine is fully opened, and the solenoid valve 2 is used in engine operating conditions where a discharge amount less than that is required. Is opened for a required time, and a part of the oil discharged by the oil pump 3 is returned to the intake side of the oil tank 1 or the oil pump through the oil return passage 7 to reduce the amount of oil supplied to the engine 4. Thus, the oil supply amount to the engine 4 can be controlled.

Since the check valve 6 is arranged in the oil passage 316 on the discharge side, the check valve 6 is opened by the discharge pressure of the oil from the oil pump 3 when the solenoid valve 2 is closed. When the oil is supplied to the engine 4 and the solenoid valve 2 is opened, the discharge pressure of the oil becomes small, the flow of the oil to the engine 4 is blocked by the check valve 6, and the oil flows through the oil return passage 7 to the oil. It is returned to the suction side of the tank 1 or the oil pump 3.

Next, the operation of the solenoid valve 2 will be described with reference to FIG. When an output 8 of an engine operating condition sensor, such as a throttle valve opening sensor, a rotation speed sensor, an oil temperature sensor, or an engine temperature sensor arranged in the engine 4, is input to the computer 5, the computer 5 operates. The amount of oil to be reduced, that is, the valve opening time of the solenoid valve 2 is calculated and an output for opening the solenoid valve 2 is supplied to the solenoid valve 2. When the excitation winding 201 of the solenoid valve 2 is excited by the output of the computer 5, the valve body 202 is attracted to the core 204 of the solenoid valve 2 against the bias of the spring 203 of the solenoid valve 2 in the valve closing direction. The valve seat 205 is separated from the valve seat 205 to open the valve.

FIG. 4 shows a second embodiment in which the relationship between the oil discharge passage 316 and the oil return passage 307 with respect to the solenoid valve 2 is different from that in FIGS. 2 and 3 by the same cross section as in FIG. Although it is a figure, the code | symbol in a figure shows the same part as the code | symbol shown in FIG. 2, FIG. In the configurations of FIGS. 2 and 3, the discharge pressure of the oil of the oil pump 3 acts in the direction in which the valve body 202 of the solenoid valve 2 is seated on the valve seat 205, while in the configuration of FIG. Since the oil discharge pressure of the valve acts in the direction of separating the valve body 202 from the valve seat 205, the strength of the spring 203 of the solenoid valve 2 is controlled by the pressure of the oil that causes the valve body 202 to open the check valve 6. It should be strong enough not to move away from the seat 205.

In each of the first and second embodiments shown in FIGS. 2, 3, and 4, two lead cams 305 at one end of the plunger 303 and two discharges formed in the pump casing 301 are provided. The configuration is shown in which the side oil passage 316 and the two solenoid valves 2 arranged in each of the two discharge side oil passages 316 are provided, but when there is one oil supply point to the engine 4, the plunger 303 It goes without saying that the lead cam 305 may be one mountain and one discharge side oil passage 316 may be formed in the pump housing 301. It is also possible to use a gear pump or trochoid pump as the oil pump.

[0019]

[Effects of the Invention] By simply opening a 2-port solenoid valve between the oil passage on the discharge side of the oil pump and the oil return passage, the oil discharged by the oil pump is returned to the suction side of the oil tank or oil pump. Since the check valve, which is generally used in the separated lubrication of a cycle engine, is located in the oil passage on the discharge side, the oil flow to the engine can be blocked. The cost of the lubricator can be reduced by using a 2-port solenoid valve, which is lower in cost than the 3-port solenoid valve, instead of the costly 3-port solenoid valve, as shown in FIG. Compared with the configuration in which the oil passage on the discharge side is shut off by a 2-port solenoid valve, there is no need to use a separate check valve in the oil return passage, so the cost of the check valve is increased. The cost of the sliding device can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining the operation of a lubricating device for a two-cycle engine according to the present invention.

FIG. 2 is a sectional view of the first embodiment of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view of a second embodiment of the present invention.

FIG. 5 shows a conventional configuration example of a lubrication device for a two-cycle engine.

FIG. 6 shows a conventional configuration example of a lubrication device for a two-cycle engine.

FIG. 7 shows a conventional configuration example of a lubrication device for a two-cycle engine.

[Explanation of symbols]

 1 Oil tank 2 Solenoid valve 3 Oil pump 4 Engine 5 Computer 6 Check valve 7 Oil return passage 8 Output of sensor for sensing engine operating condition 9 Computer output 201 Excitation winding 202 Valve body 203 Solenoid valve spring 204 Core 205 Valve seat 301 Pump housing 302 Driving worm 303 Plunger 304 Worm wheel 305 Lead cam 306 Plunger guide shaft 308 Sub-plunger 311 Pump working chamber 314 Suction side oil passage 316 Discharge side oil passage

Claims (2)

[Scope of utility model registration request] 1. A two-cycle engine (4) using an oil pump (3) driven by the rotating shaft of the engine.
Of the oil pump (3), in which the check valve (6) is arranged in the discharge-side oil passage (316), the check valve (6) of the discharge-side oil passage (316) is provided. 6) An oil return passage (7) for returning a part of the oil discharged by the oil pump (3) to the oil tank (1) or the oil pump suction side (314) is opened on the upstream side, and the oil return passage (7) is opened. 7) or the opening of the return passage (7) to the discharge-side oil passage (316), the sensor output (8) for sensing the engine operating condition is input to determine the oil supply amount to the engine (4). A normally closed two-port solenoid valve (2) that opens according to the output of a computer (5) for calculation is arranged, and the oil discharged from the oil pump is an oil tank by controlling the opening period of the solenoid valve (2). (1) or oy Controls the amount back to the pump suction side (314), said check valve (6) lubrication system for controlling two-cycle engine in accordance with the amount of oil supplied to the engine matter jaw engine operation through. 2. The check valve (6) is attached to an outlet side opening of a discharge side oil passage (316) formed in a casing (301) of the oil pump (3) and the oil return passage ( 7) is formed in the housing (301), and the oil return passage and the discharge side oil passage (316) are electrically connected by a normally closed two-port solenoid valve (2) attached to the housing (301). The lubrication device for a two-cycle engine according to claim 1, which is cut off.