JPH0696971B2 - Oil pump controller for 2-cycle engine - Google Patents

Description

Description: [Field of Industrial Application] The present invention relates to an oil pump control device used in a separate oil supply type two-cycle engine.

[Prior Art] In a separate refueling type two-cycle engine, lubricating oil is supplied to each part of the engine by a plunger type oil pump driven by a crankshaft, and the oil discharge amount per one revolution of the engine is the above-mentioned plunger. Is determined by the stroke amount.

By the way, in the conventional oil pump, the plunger is linked to the throttle, and the stroke amount of this plunger is changed according to the throttle opening. Therefore, the amount of oil corresponding to the engine load is supplied to each part of the engine through the oil pump, and the oil discharge amount of this oil pump is linear with the engine speed at each throttle opening. It is proportional.

[Problems to be Solved by the Invention] However, if the oil discharge amount per engine revolution is controlled according to the throttle opening, as shown by the broken line in FIG. 9, the throttle opening (engine load) should be constant. For example, the amount of oil discharged per engine revolution remains substantially constant even if the engine speed changes. For this reason, when the engine is operating at a high engine speed despite the small throttle opening, such as when the engine is braked with the throttle closed, the amount of oil actually supplied by the engine is not supplied. The amount of oil used tends to be insufficient.

For this reason, in the past, in order to compensate for the lack of oil in the medium / high speed range, the amount of oil supplied to the engine had to be set mainly in accordance with the required oil amount in the high speed range. .

Therefore, in the low rotation speed region, the amount of oil supplied to the engine becomes excessive, the amount of oil consumption and exhaust smoke generally increase, and there is room for improvement in terms of lubrication reliability.

The present invention has been made based on such a situation, and the amount of oil supplied to the engine can be optimally adjusted based on two control elements of the throttle opening and the engine speed, and the reliability of lubrication can be improved. And the amount of oil consumption and exhaust smoke can be reduced, and
Despite controlling the oil supply with two control elements,
The existing oil pump can be continuously used without any design changes, and the actuator and the lever of the adjusting means can be linked with each other with an extremely simple structure, which is advantageous in terms of cost reduction and few failures. Become 2
An object is to provide an oil pump control device for a cycle engine.

[Means for Solving the Problems] In order to achieve the above object, an oil pump control device for a two-cycle engine according to the present invention includes an oil pump having a plunger reciprocated by power transmission from the engine, and a throttle opening. Has a lever that is rotated according to
Adjusting means for changing the stroke amount of the plunger according to the turning angle of the lever to increase / decrease the oil discharge amount per engine revolution, and when the engine speed reaches a preset value. A direction for further increasing the stroke amount of the plunger, which is determined by the throttle opening, by linking the actuated actuator and the actuator and the lever of the adjusting means when the engine speed reaches a preset value. And linking means for operating the adjusting means.

The linking means has one end immovably fixed in the vicinity of the actuator and the other end inserted into the outer tube connected to the lever, and the outer tube inserted into the outer tube to operate the actuator. A flexible operating wire having an inner tube which is pulled in conjunction with the other end and which is pulled in conjunction with the throttle operation is provided. The operating wire has a curved portion curved in an arc shape. However, the bending portion is located between the lever of the adjusting means and the actuator.

[Operation] According to this configuration, the stroke amount of the plunger is determined according to the throttle opening degree in an operating range in which the engine speed does not reach a preset value. Then, when the engine speed exceeds the set value and reaches the operating range where the actuator operates, the actuator and the adjusting means are linked through the linking means, and the linking means is determined by the throttle opening. The adjusting means is operated in such a direction as to further increase the stroke amount of the plunger being held. For this reason, the stroke amount of the plunger is determined to be a size obtained by further adding the operation amount of the actuator to the throttle opening, and the stroke amount of the plunger increases accordingly.

Therefore, in the operating range in which the actuator is operated, the stroke amount of the plunger increases regardless of the throttle opening, so increase the oil discharge amount so that the required oil amount in the high rotation range can be satisfied. It is not necessary to set, and it is possible to prevent excessive lubrication in the low / medium speed range.

Further, in the above configuration, when the actuator is operated, the inner wire of the operation wire is pulled,
The curved portion of the outer tube is moved along the pulling direction of the inner wire, and by this movement, the lever connected to one end of the outer tube is rotated in a direction to increase the stroke of the plunger. Therefore, even though the stroke amount of the plunger is adjusted by the two control elements of the engine speed and the throttle opening, the two control elements are operated by the existing variable discharge amount type. Only the lever provided on the oil pump is used. Therefore, no change in structure is required on the oil pump side, and the existing oil pump can be continuously used as it is.

Moreover, since the above-mentioned linking means only has to bridge the operation wire consisting of the outer tube and the inner wire in a circular arc between the lever and the actuator, it can be easily assembled on the engine side. At the same time, the linking means uses the movement of the bending portion of the operation wire to rotate the lever, so that a complicated mechanical structure is not required at all, and the structure of the entire apparatus can be simplified accordingly. it can.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings applied to a motorcycle.

FIG. 1 shows a front part of a motorcycle, and reference numeral 1 is a frame. A steering head pipe 2 that pivotally supports a front fork 3 is provided at the front end of the frame 1. The steering head pipe 2 is connected with a main pipe 4 extending obliquely rearward and downward and a down tube 5 extending downward. In the space surrounded by the main pipe 4 and the down tube 5,
A separate refueling type two-cycle engine 6 is mounted.

In the cylinder block 17 of the engine 6, a pair of cylinders 7 are arranged in parallel. On the inner surface of each cylinder 7,
As shown in FIG. 2, an intake port 9 opened and closed by a piston 8, an exhaust port 10, and a scavenging port 11 are opened. The exhaust port 10 is connected to the exhaust passage 12 in the cylinder block 17. An exhaust valve 13 for advancing and retracting to the upper edge of the opening of the exhaust port 10 to change the exhaust timing is attached to the upper surface of the exhaust passage 12 facing the exhaust port 10.

The exhaust valve 13 has a substantially hourglass shape, and a cutout portion 14 matching the opening shape on the upper edge side of the opening of the exhaust port 10 is provided on a part of the outer peripheral surface of the exhaust valve 13.
A shaft portion 15 is provided at both ends of the exhaust valve 13 along the axial direction, and the shaft portion 15 is axially supported by a cylinder block 17 via a bearing 16. As shown in FIG. 4, the exhaust valves 13 of each cylinder 7 are coaxially connected to each other via a joint 13a.
Is rotated by a servo motor 19 as an actuator.

That is, the shaft portion 15 of the one exhaust valve 13 is led out to the outside of the cylinder block 17. A pulley 18 is bolted to the lead-out end of the shaft portion 15.
A wire 21 is wound between and and a pulley 20 driven by a servo motor 19. The servomotor 19 is rotated by a predetermined angle in the forward and reverse directions according to the rotation speed of the engine 6, and in the case of this embodiment, the rotation speed (rpm) of the engine 6 is changed to CDI as shown in FIG. The control unit 23 outputs a drive signal to the servo motor 19 when detected from the ignition pulse of the unit 22 and when the pulse signal exceeds a predetermined level, for example, when the engine speed of the engine 6 exceeds 5000 (rpm). There is.

In this case, when the engine 6 does not reach 5000 rpm, the outer surface of the exhaust valve 13 is
It has advanced to the upper edge of the opening of 10, and the opening height of the exhaust port 10 is lowered accordingly, and the exhaust timing is delayed.
When the rotation speed of the engine 6 exceeds 5000 (rpm), the servo motor 19 rotates the exhaust valve 13 through the pulleys 18, 20 and the wire 21 in the clockwise direction in FIG. The outer peripheral surface of the valve 13 retreats from the exhaust port 10, and the cutout portion 14 of the exhaust valve 13 coincides with the upper edge of the opening of the exhaust port 10. Therefore, the opening height of the exhaust port 10 becomes high and the exhaust timing becomes early.

On the other hand, the crankcase 24 of the engine 6 is provided with an oil pump 25 that supplies lubricating oil to the lubricated portion of the engine 6 such as the crankshaft. Details of the oil pump 25 are shown in FIGS. 5 and 6.

That is, reference numeral 26 in the drawing is a pump case, and a guide hole 27 is formed in the pump case 26. Guide hole
Plunger 28 is fitted in 27 so as to be rotatable about its axis and reciprocally movable in its axis. This plunger
28 includes a large-diameter shaft portion 29 and a small-diameter shaft portion 30. Large diameter shaft
A worm wheel 31 is formed on the outer peripheral surface of 29, and the worm wheel 31 meshes with a worm 32 that is rotationally driven by a crankshaft. Therefore, the plunger 28 is interlocked with the crankshaft via the worm wheel 31 and the worm 32, and is rotationally driven by the power transmission from the crankshaft.

At the boundary between the large-diameter shaft portion 29 and the small-diameter shaft portion 30, a groove 33 is formed which is continuous in the circumferential direction. The groove 33 is provided in the guide hole
It is opposed to the stepped portion 34 on the inner surface of the, and an annular first pump chamber 35 is formed between the stepped portion 34 and the stepped portion 34. Inside the small-diameter shaft portion 30, a cylinder hole 36 extending in the axial direction is formed. A rod 37 is slidably inserted in the cylinder hole 36 in the axial direction.
A second pump chamber 38 is formed between the end of 36. On the outer peripheral surface of the small-diameter shaft portion 30, a suction switching port 40 that communicates with the first pump chamber 35 through a communication hole 39 that extends in the radial direction of the plunger 28, a discharge switching port 41, and a suction that communicates with the second pump chamber 38. Switching port 42 and discharging switching port 43 are opened.
Both of these switching ports 40 and 41 and 42 and 43 are provided at positions facing each other in the radial direction of the small diameter shaft portion 30.

As shown in FIG. 6, the inner surface of the guide hole 27 has a plunger.
With the rotation of 28, a pair of suction ports 44 facing each other and opening the suction switching ports 40, 42 are opened to face each other. These suction ports 44 are connected to a suction passage 46 in the pump case 26. Further, on the inner surface of the guide hole 27, four discharge ports 45, which are instantaneously opposed to the discharge switching ports 41 and 43, are provided at positions orthogonal to the suction port 44 so as to face each other. Has been done. These discharge ports 45 are connected to the lubricated parts of the engine 6 through four discharge passages 47 in the pump case 26.

In the pump case 26, a rotary shaft 48 extending in a direction orthogonal to the plunger 28 is housed so as to be rotatable around its axis. The peripheral surface of the rotating shaft 48 faces one end surface of the plunger 28, and the one end surface of the plunger 28 has a cylindrical cam 49.
Are formed coaxially. On the end surface of the cylindrical cam 49, a cam surface 50 having valleys and peaks alternately is continuously formed in the circumferential direction, and the cam surface 50 is pressed against the circumferential surface of the rotating shaft 48 by the urging force of the spring 51. Has been. In the center of one end surface of the plunger 28, a protrusion 52 having a height higher than the maximum lift amount of the cylindrical cam 49 is formed. On the peripheral surface of the rotary shaft 48 facing the protrusion 52, a recess 53 continuous in the circumferential direction is formed. The bottom surface of the concave portion 53 is eccentric with respect to the rotary shaft 48, and forms a cam surface 54 that comes into contact with and separates from the protrusion 52 according to the rotation of the rotary shaft 48. Recess
53 and the protrusion 52 of the plunger 28 constitute an adjusting means for changing the stroke amount of the plunger 28.

Therefore, when the rotary shaft 48 is rotated to the fully closed position, the protrusion 52 comes closest to the cam surface 54, the stroke of the plunger 28 is limited, and the rotary shaft 48 is opened from the fully closed position. When rotated in the direction, the cam surface 54 and the protrusion 52 are separated from each other,
The stroke of the plunger 28 is designed to increase.

The tip of the rotary shaft 48 is led out of the pump case 26. A lever 55 for rotating the rotating shaft 48 in the axial direction according to the opening degree of the throttle 56 and the number of rotations of the engine 6 is attached to the lead-out portion of the rotating shaft 48.

The operation system of the rotary shaft 48 will be described with reference to FIGS. 4 and 8. Reference numeral 57 in the drawings is a flexible operation wire forming a linking means. This operating wire 57
It is composed of an outer tube 58 and an inner wire 59 slidably inserted into the outer tube 58. Wire holders 60 and 61 are caulked to both ends of the outer tube 58 of the operation wire 57. One wire holder 60 is fixed near the pulley 20 of the servomotor 19, and the other wire holder 61 is rotatably connected to a lever 55 of a rotary shaft 48 via a pin 62. Further, one end of the inner wire 59 is locked to the pulley 20 and the other end is linked to the throttle 56. Further, such an operation wire 57 has a curved portion 57a that is curved in an arc shape, and this curved portion 57a has a pulley 20a.
It is located between the lever and the lever 55.

Therefore, when the throttle 56 is opened, the inner wire 59 of the operation wire 57 is pulled in the direction of arrow A in FIG. 4, so that the portion from the curved portion 57a of the operation wire 57 to the other wire holder 61 as shown in FIG. Moves in the pulling direction of the inner wire 59 and rotates the lever 55 from the fully closed position in the opening direction by a predetermined angle. Also, the engine 6 speed is 5000
(Rpm) above and the pulley 2
When 0 is rotated in the direction of the arrow B that opens the exhaust valve 13, only the inner wire 59 is pulled in the opposite direction this time, so the portion from the bending portion 57a of the operation wire 57 to the other wire holder 61 is the same as above. Move the inner wire 59 in the pulling direction.

Therefore, the wire holder 61 is pushed out, and the lever 55 is rotated in the opening direction by a predetermined angle as in the case where the throttle 56 is opened.

Next, the operation of the above configuration will be described.

When the plunger 28 is rotated by the power transmission from the crankshaft with the start of the engine 6, the cam surface of the cylindrical cam 49 is
50 makes sliding contact with the peripheral surface of the rotating shaft 48, and the plunger 28 makes the cam surface 50
Reciprocates according to the shape of. Plunger 28 is a spring
When it is slid to the right side in FIG. 5 by the urging force of 51, the internal volumes of the first pump chamber 35 and the second pump chamber 38 are expanded, and at the same time, the suction switching ports 40 and 42 coincide with the suction port 44. To do. Therefore, the plunger 28 enters the suction stroke, and the lubricating oil is sucked into the pump chambers 35, 38 through the suction port 44.

Next, when the plunger 28 is slid to the left side in FIG. 5 according to the shape of the cam surface 50, the internal volumes of the first pump chamber 35 and the second pump chamber 38 are reduced this time, and the sucked lubricating oil At the same time that is pressurized, the discharge switching ports 41 and 43 coincide with the one discharge port 45. Therefore, the lubricating oil pressurized in the pump chambers 35, 38 is discharged to each lubricated portion of the engine 6 through the discharge port 45 and the discharge passage 47 continuous with the discharge port 45.

Note that, in such a lubricating oil discharge operation, the discharge port 45 is opened at a position facing each other on the inner surface of the guide hole 27, that is, with a phase difference of 180 ° in the rotational direction of the plunger 28. Therefore, it is performed twice during one rotation of the plunger 28.

By the way, since the amount of lubricating oil discharged per one revolution of the engine 6 (crankshaft) is determined by the stroke amount of the plunger 28, the opening of the throttle 56 is small and the number of revolutions of the engine 6 is 5000 ( When the operating state is in the low rotation speed range such that the inner wire 59 is not pulled in both directions A and B, the amount of movement of the bending portion 57a of the operating wire 57 is also small. . Therefore, the rotation shaft 48 is rotated to the fully closed position, and when the rotation shaft 48 is at the fully closed position, the cam surface 54 of the recess 53 and the protrusion 52 of the plunger 28 are closest to each other. There is a positional relationship.

Therefore, the projection 52 contacts the recess 53 before the valley of the cam surface 50 of the cylindrical cam 49 slides on the rotating shaft 48 as the plunger 28 rotates. Due to this contact, the plunger 28 can no longer make a stroke, and the lift amount of the cylindrical cam 49 is apparently reduced.

Therefore, the stroke of the plunger 28 is shortened, and the amount of lubricating oil discharged is also reduced.

In such an operating state, the throttle 56 is fully opened, that is, as shown in FIG.
When set to 1/1, the rotating shaft 48 is rotated in the opening direction by a predetermined angle from the fully closed position via the operation wire 57 and the lever 55, and the bottom surface of the concave portion 53 of the rotating shaft 48 extends from the protrusion 52 of the plunger 28. Separate. As a result, the sliding range of the cam surface 50 with respect to the rotating shaft 48 becomes longer, so that the stroke of the plunger 28 increases and the amount of oil discharged per revolution of the engine 6 increases, as shown in FIG.

When the throttle 56 is opened, the engine 6 speed is increased to 50
When it reaches the medium / high rotation range exceeding 00 (rpm), the servo motor 19 operates and the pulley 20 rotates. For this reason, the exhaust valve 13 begins to open, and the exhaust timing becomes earlier. In addition, the inner wire 59 of the operation wire 57 is attached to the pulley 20.
Since the inner wire 59 is connected to the pulley 20
The portion from the curved portion 57a of the operation wire 57 to the other wire holder 61 is wound up on the inner wire 59a.
Move in the pulling direction. Therefore, the lever 55 is further rotated in the opening direction, so that the cam surface 50 with respect to the rotation shaft 48 is rotated.
The sliding range of is longer.

Therefore, the stroke of the plunger 28 also becomes longer, and as shown in FIG.
At the time of reaching (rpm), the discharge amount of the lubricating oil rapidly increases.

On the other hand, when the engine 6 is in the high rotation speed range exceeding 5000 (rpm) and the engine brake is operated with the throttle 56 fully closed, for example, if the engine 6 rotation speed is 5000 (rpm) or more. The exhaust valve 13 is held in the open position retracted from the upper edge of the opening of the exhaust port 10. Therefore, the lever 55 of the rotary shaft 48 is kept rotated in the opening direction by the operation wire 57, so that the rotation speed of the engine 6 is in the high rotation range even if the engine load is reduced. As long as it exists, the discharge amount of the lubricating oil can be maintained as it is.

According to such an embodiment of the present invention, when the number of revolutions of the engine 6 exceeds 5000 (rpm), the rotating shaft 48 that is opened by the operation wire 57 by an angle corresponding to the throttle opening is further increased. Since it is rotated in the opening direction and the rotation amount of the pulley 20 is added to the rotation shaft 48, the stroke of the plunger 28 becomes large irrespective of the throttle opening (engine load). The oil discharge amount of increases.

For this reason, it is not necessary to set a large amount of oil discharge over the entire rotation range of the engine 6 so that the required oil amount in the high rotation range can be satisfied, unlike in the conventional case. It is possible to prevent excessive oil supply in the low / medium rotation range while sufficiently securing the oil discharge amount of.

Therefore, the reliability of lubrication is improved, and the amount of oil consumption and exhaust smoke can be reduced.

In addition, the stroke of the plunger 28 of the oil pump 25
Since it is controlled by both the engine speed and the opening of the throttle 56, the amount of lubricating oil discharged can be automatically adjusted to the required amount according to all operating conditions of the engine 6, and the lubrication reliability can be improved. There is an advantage that the property is remarkably improved.

Moreover, according to the above configuration, the stroke of the plunger 28 is adjusted to increase or decrease by the two control elements of the engine speed and the throttle opening, but the common rotation is operated by these two control elements. Since only the shaft 48 is used, there is no need to change the basic structure of the oil pump 25, and the structure of the oil pump 25 does not become complicated.

In addition, it can be applied as it is to a conventional variable discharge type oil pump in which only the throttle opening is used as a control element of the plunger 28, and there is an advantage that it is excellent in versatility.

Further, in the above configuration, the operation wire 57 including the outer tube 58 and the inner wire 59 is attached to the oil pump 25.
Since it suffices that the lever 55 and the pulley 20 of the servomotor 19 are curved in an arc shape, the operating wire 57 can be easily attached to the engine 6 side. Further, since the operation wire 57 rotates the lever 55 by the movement of the curved portion 57a curved in an arc shape, no complicated mechanical structure part is required at all, and the lever 55 and the pulley 20 are interlocked. The structure can be greatly simplified.

Therefore, when the lever 55 and the pulley 20 are interlocked with each other, there is an advantage that a troublesome adjustment work becomes unnecessary, and the breakdown is reduced due to the simplification of the structure, which is advantageous in terms of cost.

In the above embodiment, the rotary shaft of the oil pump is operated by the power transmission from the servo motor that drives the exhaust valve, but the present invention is not limited to this, and for example, to operate the rotary shaft. Alternatively, the rotation shaft may be operated by providing a dedicated motor and controlling the motor according to the rotation speed of the engine.

[Effects of the Invention] According to the present invention described in detail above, it is not necessary to set a large amount of oil discharge over the entire engine rotation range, and a sufficient amount of oil discharge can be secured in a high engine speed range. At the same time, it is possible to prevent excessive refueling in the low / medium rotation range. Therefore, the reliability of lubrication is improved, and the amount of oil consumption and exhaust smoke can be reduced.

Moreover, even though the stroke of the plunger is increased or decreased by the two control elements of the engine speed and the throttle opening, only the common lever is operated by these two control elements. There is no need to change the basic structure of, and the existing variable discharge type oil pump can be used continuously.

Further, in the case of the above configuration, since the operation wire formed of the outer tube and the inner wire may be hung around the lever and the actuator in a curved arc shape,
This operation wire can be easily attached to the engine side. At the same time, since the linking means rotates the lever by the movement of the bending portion of the operation wire, no complicated mechanical structure is required, and the interlocking structure of the actuator and the lever can be extremely simplified. . Therefore, when the actuator and the lever are interlocked with each other, troublesome adjustment work becomes unnecessary, and a stable oil supply with few malfunctions is possible.
There is an advantage that it is convenient in terms of cost.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a side view of the front of a motorcycle, FIG. 2 is a sectional view of a two-cycle engine, and FIG. 3 shows an exhaust valve control system. Block diagram, FIG. 4 is a configuration diagram showing a control system of an oil pump and an exhaust valve, FIG. 5 is a sectional view taken along line VV in FIG. 4, and FIG. 6 is VI- in FIG. FIG. 7 is a sectional view taken along line VI, FIG. 7 is a sectional view taken along line VII-VII in FIG. 4, FIG. 8 is an explanatory view of the operation of the oil pump lever, and FIG. It is a characteristic view which shows the relationship of the oil discharge amount with respect to a stroke. 6 …… 2-cycle engine, 19 …… actuator (servo motor), 25 …… oil pump, 28 …… plunger, 48,52,53 …… adjusting means (rotating shaft, protrusion, recess), 55 …… Lever, 56 ... Throttle, 57 ... Coupling means (operation wire), 57a ... Bending part, 58 ... Outer tube, 59 ... Inner wire.

Claims (1)

[Claims] 1. An oil pump having a plunger reciprocated by power transmission from an engine, and a lever rotated in accordance with a throttle opening, and the stroke amount of the plunger is set to a rotation angle of the lever. By adjusting the amount of oil discharged per engine revolution by increasing or decreasing, the actuator that is activated when the engine revolution speed reaches a preset value, and the engine revolution speed is preset. When the above value is reached, the actuator and the lever of the adjusting means are linked to operate the adjusting means in a direction to further increase the stroke amount of the plunger determined by the throttle opening. The linking means has one end immovably fixed in the vicinity of the actuator and the other end fixed to the actuator. Flexibility having an outer tube connected to the bar and an inner tube that is inserted into the outer tube and has one end pulled in conjunction with the operation of the actuator and the other end pulled in conjunction with throttle operation This operation wire has a bending portion that is curved in an arc shape,
The oil pump control device for a two-cycle engine, wherein the curved portion is located between the lever of the adjusting means and the actuator.