JP3156214B2 - Lubrication pump for two-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating pump for a two-stroke engine, and more particularly to a dynamic pump having a wide dynamic range. The present invention relates to an improvement of a pump structure which can be variably controlled.

[0002]

2. Description of the Related Art There are two lubrication systems for a two-stroke engine: a mixed lubrication system using a mixed fuel, and a separated lubrication system in which lubricating oil is directly supplied by a lubrication pump. A mechanically driven plunger pump is generally used as the lubrication pump. This is achieved by disposing a distributor in a pump casing so as to be rotatable, disposing a plunger in the distributor so as to be movable in the axial direction, driving the distributor to rotate with an engine output, and connecting the plunger to the distributor. The lubricating oil is sucked by a stroke formed by a cam formed on the end face of the viewer, and the lubricating oil is discharged by pressing the plunger with a spring force. In addition, this conventional pump is provided with an adjust pulley that regulates the magnitude of the stroke of the plunger according to the operating state of the engine.

In a multi-cylinder engine, the required amount of lubricating oil may be different for each cylinder, and the required amount of lubricating oil also changes according to the operating state of the engine. As a conventional lubricating device that meets these demands, a discharge passage is branched into a plurality of parts in the middle, a three-way solenoid valve is provided in each branch passage, and a return passage to an oil tank is provided. Some control devices are provided to control the opening and closing of the solenoid valve according to the amount of lubricating oil.

[0004]

In this type of lubricating pump, it is required that the amount of lubricating oil can be controlled with a width as wide as possible in accordance with the operating state of the engine, that is, the dynamic range must be expanded. The dynamic range of the conventional lubricating pump is determined by the cam height and the stroke control width of the cylindrical cam, but these values are naturally limited, and therefore the dynamic range of the conventional pump cannot be so large.

In the conventional lubricating apparatus described above, in order to control the oil amount for each cylinder, a solenoid valve, a return passage, and the like are required for each cylinder, so that the cost is high and a large arrangement space is required. There is a problem.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a lubrication pump for a two-stroke engine which can expand a dynamic range and can control an oil amount to be optimum for each cylinder. .

[0007]

According to a first aspect of the present invention, there is provided a casing having a valve hole communicating with a lubricating oil inlet and a discharge port, and a casing rotatably and axially inserted into the valve hole. A valve body, a hydraulic chamber that generates hydraulic pressure by axial movement of the valve body, a plurality of communication holes that communicate the hydraulic chamber with the inlet or discharge port depending on the angular position of the valve body, A lubricating pump for a two-stroke engine, comprising: a rotary driving means for intermittently driving a body by a predetermined angle; and an axial driving means for moving the valve body in an axial direction.

[0008] The invention of claim 2 is characterized in that a plurality of the discharge ports are formed and the communication hole is made one, and the invention of claim 3 faces the valve body in the valve hole. And an adjusting rod that is inserted movably in the axial direction and forms a bottom surface of the hydraulic chamber, and a capacity control unit that variably controls the axial position of the rod.

[0009]

According to the lubricating oil pump according to the first aspect of the present invention,
Since a plurality of communication holes communicating the hydraulic chamber and the introduction port or the discharge port are formed, the discharge is performed only a plurality of times per one rotation of the valve body, so that the maximum oil supply amount can be increased accordingly. Further, in the present invention, the rotation driving means for intermittently rotating the valve body by a predetermined angle is provided. By increasing the discharge interval, the minimum oil supply amount can be made extremely small, and as a result, the dynamic range can be expanded. .

According to the lubricating oil pump according to the second aspect of the present invention, since the casing has a plurality of discharge ports, lubricating oil is discharged from a plurality of locations per one rotation of the valve element. Therefore, by connecting each discharge port to the lubricating oil supply section of each cylinder,
Lubricating oil can be individually supplied to each cylinder, and the structure is extremely simple as compared with a conventional one equipped with a three-way solenoid valve.

According to the third aspect of the present invention, an adjusting rod is inserted into the valve hole, a hydraulic chamber is formed by the rod, the valve body and the inner surface of the valve hole, and the rod is moved forward and backward to change the volume of the hydraulic chamber. Therefore, by moving the rod forward and backward in accordance with the required oil amount of each cylinder, the optimum oil amount can be supplied to each cylinder.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 are views for explaining an oil pump of a two-stroke engine according to an embodiment (first embodiment) according to the first and third aspects of the present invention. FIG. 1 employs the oil pump of the embodiment. FIG. 2 is a sectional plan view of the oil pump, and FIG. 3 is a sectional front view of the oil pump.

In these figures, reference numeral 1 denotes a lubricating device for a two-stroke engine that supplies lubricating oil to the intake passage 8 downstream of the carburetor. The lubricating device 1 has an inlet 3 of an oil pump 2 connected to an oil tank 5 via an inlet hose 4, and a discharge port 6 connected to a downstream side of a carburetor of an intake passage 8 via a discharge hose 7. It is configured. Reference numeral 9 denotes a control device for controlling the rotation and displacement of the oil pump 2.

The oil pump 2 has a pump case 10
A valve mechanism 11 is accommodated and arranged inside the pump case 10, and a main step motor 12 for rotation control for rotating the valve mechanism 11 is mounted on the upper part of the pump case 10. The pump case 10
The sub-step motor 14 for driving the capacity control mechanism 13 is attached to the side wall of the motor.

The pump case 10 has a structure in which an upper end opening of a lower case 15 having a bottomed cylindrical shape is closed by a lid case 16. It is formed so as to form an angular interval. The main step motor 12 is fixed to the lid case 16, and a drive shaft 12 a of the motor 12 projects into the pump case 10.

The pump mechanism 11 includes the lower case 1
A valve case (corresponding to a casing of the present invention) 17 arranged and fixed in the valve 5, and a valve element rotatably and axially movably inserted into a valve hole 17 a formed in the axis of the valve case 17. 18 and a drive cap 19 for driving the valve element 18 to rotate.

The valve case 17 has a disk shape, and is formed such that an inlet hole 17b and a discharge hole 17b for connecting the inlet port 3 and the discharge port 6 to the valve hole 17a respectively form an angular interval of 90 degrees. I have. 17c is the above-mentioned introduction hole 1
7b and a communication hole that communicates with the inside of the pump case 10.
A cam 17d is formed on the upper surface of the valve case 17 in a ring shape.

A drive rod 20 is inserted and fixed to the upper end of the valve element 18 in a direction perpendicular to the axis. The drive rod 20 is in sliding contact with a cam 17d of the valve case 17.
The outwardly protruding end of the drive rod 20 is locked in a locking groove 19a formed in the drive cap 19,
Further, a discharge spring 21 for urging the drive rod 20 downward in the figure is interposed between the center recess 19b of the cap 19 and the drive rod 20. Further, the output shaft 12a of the main step motor 12 is inserted and fixed to the drive cap 19. Thereby, the valve element 18
It is rotationally driven by the step motor 12, and the cam 17d,
And driven in the axial direction by the discharge spring 21. Therefore, the stepping motor 12 is a rotary driving unit, and the cam 17d and the discharge spring 21 are an axial driving unit.

An adjusting rod 22, which constitutes a part of the capacity control mechanism 13, is inserted in the lower part of the valve hole 17a so as to be movable in the axial direction, and the upper end surface of the rod 22 and the inner surface of the valve hole 17a. , And a space surrounded by the lower end surface of the valve element 18 is a hydraulic chamber. In addition, the valve element 18 includes:
A communication hole including a vertical hole 18a communicating with the hydraulic chamber and horizontal holes 18b and 18c orthogonal to the vertical hole 18a is formed. The horizontal holes 18b and 18c communicate with the introduction hole 17b or the discharge hole 17c depending on the angular position of the valve element 18.

The displacement control mechanism 13 includes an adjusting rod 22, an eccentric cam 23 that changes the axial position of the rod 22 to change the volume of the hydraulic chamber, and urges the adjusting rod 22 downward in the figure. And a return spring 24 that performs the operation. The eccentric cam 23 is supported by a support shaft 25 inserted and fixed near the lower end of the lower case 15. The eccentric cam 23 is connected to the output shaft 14 of the sub-step motor 14.
a, which is fixed to a driving rod 26 which is driven to rotate by a.
The sub-step motor 14 and the displacement control mechanism 13 constitute a displacement control means. Reference numeral 27 denotes a cap for closing the lower opening of the capacity control mechanism 13.

Next, the operation and effect of this embodiment will be described. In the device 1 of the present embodiment, the main step motor 12 rotates 45 degrees at intervals with a time interval according to the engine operating state, whereby the valve element 18 is driven to rotate via the drive cap 19 and the drive rod 20.

When one of the lateral holes 18b and 18c of the valve element 18 comes to the illustrated suction stroke position, the drive rod 20
Is pushed up by the convex portion of the cam 17d, so that the valve body 18 rises to make the hydraulic chamber a negative pressure, and lubricating oil is sucked into the hydraulic chamber. When one of the lateral holes 18b, 18c comes to the illustrated discharge stroke position, the drive rod 20
Is located in the concave portion of the cam 17d, and the valve element 18 is
And the lubricating oil is discharged.

The sub-stepping motor 14 is rotated to an angular position corresponding to the required discharge amount per operation, whereby the eccentric cam 23 adjusts the vertical position of the adjusting rod 22. As a result, the volume of the hydraulic chamber is reduced. And the discharge amount per discharge is controlled to the required value.

In the pump 2 of the present embodiment, when the discharge amount is increased, the volume of the hydraulic chamber is increased by lowering the adjusting rod 22 or the rotational speed of the valve element 18 is increased. Of course, at the same time, if the volume is increased and the speed is increased, the discharge amount can be further increased. Although the above-mentioned volume expansion and speed increase are naturally limited, in the present embodiment, the lubricating oil is discharged twice during one rotation of the valve element 18, so that the maximum lubricating amount is also increased from this point. Can increase.

On the other hand, when the discharge amount is to be reduced, the adjusting rod 22 may be raised to reduce the volume of the hydraulic pressure generating chamber, or the rotational speed of the valve element 18 may be reduced. Is also good. In this case, since the main step motor 12 is employed in the present embodiment, the rotation speed can be freely reduced, and at this point, the amount of refueling can be minimized.

As described above, in this embodiment, the maximum lubricating oil supply amount can be greatly increased, and the minimum lubricating oil supply amount can be made very small, so that the so-called dynamic range can be expanded.

In the above embodiment, two horizontal holes 18b and 18c as communication holes are formed at an interval of 180 degrees. However, the number of the horizontal holes 18b and 18c is not limited to two. In this case, three discharges can be performed per one rotation of the valve element, and the dynamic range can be further expanded.

FIGS. 4 and 5 are views for explaining a lubricating apparatus according to an embodiment (second embodiment) according to the second and third aspects of the present invention. Or a corresponding part is shown. The second embodiment is an example in which the lubricating oil is discharged from two discharge ports per rotation of the valve element 18.

In this embodiment, the introduction hole 17 of the valve case 17 is provided.
b and a communication port 17 at a position facing
d 'is formed. The lubricating oil from the oil tank is introduced from the communication hole 17d into the communication hole 17d 'via the upper space of the pump case 10. The discharge holes 17c and the discharge ports 6b are located at positions facing the discharge holes 17c and 6b.
c 'and a discharge port 6'. On the other hand, the lateral hole forming the communication hole of the valve element 18 has only 18b.
Although not shown, the pump of this embodiment also includes a displacement control mechanism 13 and a sub-step motor 14.

The discharge port 6 is connected to a front cylinder intake passage 8 of, for example, a V-type horizontal engine by a discharge hose 7, and the discharge port 6 'is connected to a discharge hose 7'.
Is connected to the rear cylinder intake passage 8 '.

In the pump of the present embodiment, the lubricating oil sucked in the suction stroke is discharged from the discharge port 6 in the discharge stroke and supplied to the front cylinder intake passage 8 with the rotation of the valve element 18. On the other hand, the lubricating oil sucked in the suction stroke is discharged from the discharge port 6 'in the discharge stroke and supplied to the rear cylinder intake passage 8'.

Here, in the V-type engine, the required amount of lubricating oil may differ between the front cylinder and the rear cylinder. For example, since the rear cylinder is harder to hit by the cooling air than the front cylinder, the heat load is large, and therefore the required amount of lubricating oil of the rear cylinder may be larger than that of the front cylinder. The capacity control means operates. This is realized by the step motor 14 changing the angular position of the eccentric cam 23 so that the volume of the hydraulic chamber in the suction stroke is larger than the volume in the suction stroke.

In the second embodiment, the case where the number of discharge ports is two has been described. However, the number of discharge ports is not limited to two. For example, three discharge ports may be provided at intervals of 120 degrees. In this way, three cylinders can be refueled individually.

Further, in the above-described embodiment, the horizontal holes 18b and 18c as communication holes are formed in the valve body 18 itself, but this may be configured as shown in FIG. In the figure, the same reference numerals as those in FIG. 3 indicate the same or corresponding parts. The valve element of the present embodiment has a valve hole 1
7a, a valve stem 26 rotatably and axially immovable, a valve stem 27 rotatably and axially displaceable within the valve stem 26, and a valve stem 27 facing the valve stem 27. And a plug 29 inserted into the valve cylinder 26,
The space surrounded by these members 26, 27 and 29 is a hydraulic pressure generation chamber a. The communication hole 2 is formed in the valve cylinder 26.
6a are formed. 31 and 32 are valve cylinders 26,
A spring 26b for urging the valve rod 27 downward is an insertion hole for the drive shaft 20. Reference numerals 42b and 42a denote ejection position detecting springs and terminals.

In each of the above embodiments, the lubricating oil is supplied to the intake passage. However, the lubricating oil pump of the present invention can of course be applied to a case where the lubricating oil is directly supplied to the lubricated portion.

[0036]

According to the lubricating oil pump according to the first aspect of the present invention, since the communication holes are made plural and discharged plural times per rotation, the maximum supply amount of lubricating oil can be increased accordingly. Since the rotation driving means for intermittently rotating the valve body by a predetermined angle is provided, the minimum oil supply amount can be made extremely small by increasing the discharge interval, and as a result, the dynamic range can be expanded.

According to the lubricating oil pump according to the second aspect of the present invention, since the plurality of discharge ports are used to discharge the lubricating oil from a plurality of positions per rotation of the valve element, each discharge port is provided with the lubricating oil of each cylinder. By connecting to the supply section, lubricating oil can be individually supplied to each cylinder, and there is an effect that the structure can be extremely simplified as compared with a conventional one provided with a three-way solenoid valve or the like.

According to the third aspect of the present invention, a hydraulic chamber is formed by the adjusting rod inserted into the valve hole, the valve body, and the inner surface of the valve hole.
Since the hydraulic chamber volume is made variable by moving the adjusting rod forward and backward, by moving the rod forward and backward according to the required lubricating oil amount of each cylinder, there is an effect that an optimal amount of lubricating oil can be supplied to each cylinder.

[0039]

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a lubricating device including an oil pump according to a first embodiment of the present invention.

FIG. 2 is a sectional plan view of the oil pump according to the first embodiment.

FIG. 3 is a sectional side view of the oil pump according to the first embodiment.

FIG. 4 is a sectional plan view of an oil pump according to a second embodiment of the present invention.

FIG. 5 is an overall configuration diagram of a lubricating device including the oil pump according to the second embodiment.

FIG. 6 is a cross-sectional side view for explaining a modified example of the valve body.

[Explanation of symbols]

3 Inlet port 6, 6 'Discharge port 12 Main step motor (rotation drive means) 13, 14 Capacity control mechanism, sub-step motor (capacity control means) 17 Valve case (casing) 17a Valve hole 17d, 21 Cam, discharge spring ( Axial drive means) 18 Valve element 18b, 18c Side hole (communication hole) 22 Adjustment rod 26, 27 Valve cylinder, valve stem (valve element)

Claims (3)

(57) [Claims] 1. A casing having a valve hole communicating with a lubricating oil introduction port and a discharge port, a valve element rotatably and axially inserted into the valve hole, and an axial direction of the valve element. A hydraulic chamber that generates hydraulic pressure by movement, a plurality of communication holes that communicate the hydraulic chamber with the introduction port or the discharge port depending on the angular position of the valve body, and intermittently rotationally drive the valve body by a predetermined angle. A lubricating pump for a two-stroke engine, comprising: a rotary drive means; and an axial drive means for moving the valve body in an axial direction. 2. A casing having a valve hole communicating with a lubricating oil introduction port and a plurality of discharge ports, a valve body rotatably and axially inserted into the valve hole, A hydraulic chamber that generates hydraulic pressure by axial movement, a communication hole that communicates the hydraulic chamber with the introduction port or any of the discharge ports depending on the angular position of the valve body, and intermittently intermittently moves the valve body by a predetermined angle. A lubricating pump for a two-stroke engine, comprising: a rotary drive unit that rotates and an axial drive unit that moves the valve body in an axial direction. 3. An adjusting rod according to claim 1, wherein the adjusting rod is inserted into the valve hole so as to be axially movable so as to face the valve body, and forms a bottom surface of the hydraulic chamber. A lubrication pump for a two-stroke engine, comprising: a displacement control means for variably controlling a directional position.