JPS6093106A - Oil pump for separate oil supply type engine - Google Patents

Abstract

PURPOSE:To permit a proper amount of oil to be supplied, improve reliability and reduce oil consumption by changing the slide range of a pivotable member interlocked with the load and rotational frequency of an engine to a plunger cam surface according to the pivotal angle for controlling a stroke. CONSTITUTION:When the opening of a throttle is small and the rotational frequency of an engine is in the low region, a pivotable shaft 48 is pivoted to the fully closed position so that a cam surface 54 approaches a projection 52 the most closely. And before each portion of the cam surface 50 slidably contacts the pivotable shaft 48, the projection 52 contacts a recess 53 to reduce the lift of a cylindrical cam 49 apparently, shorten the stroke of a plunger 28 and reduce the discharge of oil. Also, when the throttle is fully opened as a load is increased, the pivotal shaft 48 is pivoted to the opening direction, the projection 52 is spaced from the recess 53 and the region of the pivotal shaft 48 contacting the cam surface 50 is lengthened so that the stroke of the plunger 28 is elongated and the discharge of oil is increased. Thus, the discharge of oil can be controlled to be a required amount corresponding to the running condition and improve the reliability of lubrication.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to, for example, an oil pump for a two-stroke engine with separate oil supply.

[Technical background of the invention and its problems]

Generally, in this type of two-stroke engine, lubricating oil is forcibly supplied to each part of the engine by a plunger-type oil pump driven by power transmission from the crankshaft, and the amount of oil supplied by this oil pump is determined by the stroke of the plunger. Determined by quantity.

Incidentally, there is conventionally known an oil pump in which the stroke amount of the plunger is adjusted and controlled according to the throttle opening to supply an amount of oil commensurate with the load of the engine.

However, according to this structure, the drive source of the oil pump itself is the engine, so if the load knob throttle opening is constant as shown by the broken line in Figure 9, the oil supply to the engine speed is The amount remains approximately constant, and there is a tendency for the oil amount to be insufficient, especially in the high rotation range.

For this reason, conventionally, in order to compensate for the lack of oil in the medium and high speed range, the oil supply amount had to be set in accordance with the required oil amount in the high speed range. If the supply amount was too large, overall oil consumption and exhaust smoke would increase, and there was still room for improvement in terms of reliability.

[Purpose of the invention]

The present invention was made based on these circumstances, and
The purpose of the present invention is to provide an oil pump for a separate oil supply type engine that can supply an appropriate amount of oil commensurate with the load and rotational speed of the engine, improve lubrication reliability, and reduce oil consumption. do.

[Summary of the invention]

That is, in order to achieve the above-mentioned object, the present invention has a rotating member that is rotated by a predetermined angle in conjunction with the load and rotational speed of the engine slidably contact the cam surface of the plunger, and the rotating member and the plunger are in sliding contact with each other. A contact portion is provided at a portion facing the cylindrical cam to change the range of sliding contact along the circumferential direction of the rotary member with respect to the cam surface by being moved toward and away from the rotary member according to the rotation angle of the rotary member. It is characterized in that the stroke of the plunger is adjusted and controlled by apparently increasing the lift amount of the cam surface.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a motorcycle.

In Fig. 1, 1 is a frame, and a front fork 3 is pivotally supported on a steering head pipe 2 at the front end of the frame. It is equipped with a 2F cycle engine 6. As shown in FIG. 2, an intake port 9, an exhaust port 10, a scavenging port 11, etc., which are opened and closed by a piston 8, are provided on the inner surface of the cylinder 7 of this engine 6. An exhaust pulp 13 is mounted on the upper surface of the exhaust passage 12 connected to the exhaust port 10 so as to be able to move forward and backward toward the upper edge of the opening of the exhaust port 10 to change the exhaust timing. Since this exhaust valve 13 is already known, a detailed explanation thereof will be omitted, but a notch that matches the opening shape of the upper edge of the opening of the exhaust port 10 is formed in a part of the outer circumferential surface that is roughly shaped like a drum. It has a section 14 whose ends 15,15 are journalled in a cylinder block 17 via bearings 16. One shaft portion 15 is led out to one side of the cylinder block 17, and a wire 21 is wound between a pulley 18 bolted to this lead-out end and a pulley 20 on the servo motor 19 side. This servo motor 19 is rotated in forward and reverse directions according to the rotation speed of the engine 6, and in the case of this embodiment, the servo motor 19 is
The engine speed (rpm) is 60 CD as shown in the figure.
It is detected from the ignition pulse of the I unit 22, and if this pulse signal exceeds a predetermined level, for example, the rotation speed ("-" C50
When the speed reaches 00 (rpm) or more, the control unit 23 gives a drive signal to the nervo motor 19. Therefore, the rotation speed of the engine 6 is 5000
(rpm), the outer circumferential surface of the exhaust pulp 13 extends to the upper edge of the opening of the exhaust port 10. When the rotation speed exceeds 5000 (rpm) from this state, the servo motor 19 moves the pulleys 1B and 20. Since the exhaust pulp 13 is rotated by a predetermined angle via the wire 21, the outer circumferential surface on the opposite side to the notch 14 retreats from the upper edge of the opening of the exhaust port 10, thereby advancing the exhaust timing.

An oil pump 25 is attached to the crankcase 24 side of the engine 6 to supply lubricating oil to each lubricating part such as the crankshaft. Details of this oil pump 25 are shown in FIGS. 5 and 6. ``In other words, 26 is the pump case, and a plunger 28 is fitted into a guide hole 27 formed in the pump case 26 so as to be rotatable around the axis and reciprocated in the axial direction. The plunger 28 is divided into a large-diameter shaft portion 29 and a small-diameter shaft portion 30 at the middle portion along the axial direction, and a worm gear 31 on the outer peripheral surface of the large-diameter shaft portion 29 receives power from the crankshaft. By meshing the worm wheel 32 which is rotationally driven by transmission, the worm wheel 32 is rotated in conjunction with the crankshaft.'' At the boundary between the two shaft portions 29 and 30, there is a circumferential groove. A continuous groove 33 is formed, and this groove 33 faces a step 34 on the inner surface of the recording guide hole 27 and forms an annular first pump chamber 35 between the groove 33 and the step 34 on the inner surface of the guide hole 27. . Further, a rod 37 is fitted into the cylinder hole 36 formed in the small diameter shaft portion 3o so as to be slidable in the axial direction, and there is a gap between the tip surface of the rod 37 and the bottom surface of the cylinder hole 36. Two pump chambers 38 are formed. The outer peripheral surface of the small diameter shaft portion 30 is provided with a suction switching port 40, a discharge switching port 41, and a second pump chamber 3, which are connected to the first pump chamber 35 through a communication hole 39 along the radial direction.
8, a suction switching port 42 and a discharge switching port 43 are opened.
3 are located on both sides of the small diameter shaft portion 30 in the radial direction.

In addition, a pair of suction ports 44.44 are opened in the inner surface of the guide hole 27 so as to face each other, and these suction ports 44.44 are opposed to each other and are aligned with the suction switching port 40.42 as the plunger 28 rotates. 44. At a position orthogonal to 44, there are four discharge ports 4 that momentarily oppose the discharge switching ports 41 and 43.
5... are set up in pairs, facing each other. The suction ports 44, 44 are connected to the suction passage 46, and the discharge ports 45 are connected to each lubricating part of the engine 6 via four discharge passages 47.

On the other hand, a rotation shaft 48 as a rotation member is rotatably accommodated in the pump case 26 along a direction perpendicular to the plunger 28 . The circumferential surface of the rotation shaft 480 is the plunger 2
A cylindrical cam 49 is coaxially formed on one end surface of the plunger 28, facing one end surface of the plunger 28. The cylindrical cam 49 has a cam surface 50 continuous in the circumferential direction on its end surface and having valleys and peaks alternately. Elastic sliding contact with the surface. At the center of one end surface of the pusher 28, there is a protrusion 5 that exceeds the maximum lift amount of the cylindrical cam 49.
2 is formed, and four portions 53 continuous in the circumferential direction are formed on the circumferential surface of the rotating shaft 48 facing the protrusion 52. The bottom surface of the four parts 53 is located eccentrically with respect to the rotating shaft 48, and forms a cam surface 54 that approaches and separates from the protrusion 52 according to the rotation of the rotating shaft 48, and these recesses 53 and the protrusion 52 constitute a contact portion that changes the stroke of the plunger 28. The tip of the rotation shaft 48 is led out of the pump case 26, and a lever 55 is fixed to this lead-out portion.

This lever 55 is rotated by a predetermined angle depending on the opening degree of the throttle 56 and the rotational speed of the engine 6. To further explain this operating system, reference numeral 57 is a flexible operating wire, which is constructed by inserting an inner wire 59 into a jacket tube 58. Wire holders 60 and '61 are fastened to both ends of the operating wire 57, and one of the wire holders 6o is fixed near the pulley 2°, and the other wire holder 61 is fixed through a pin 62. It is rotatably connected to the lever 55. The operating wire 57 is curved into an arc between the pulley 20 and the lever 55, and one end of the five inner wires is locked to the pulley 20, and the other end of the inner wire 59 is attached to the wire holder 61. It is extended as it is and is interlocked with the throttle 56. Therefore, when the throttle 56 is opened, the inner wire 59 is pulled in the direction of the arrow in FIG. When the pulley 2θ is rotated by a predetermined angle in the opening direction from the fully open position, and the pulley 2θ is rotated in the direction of arrow B to open the exhaust pulp 13, only the inner wire 59 is pulled in the opposite direction, so that the outer sheath tube 58 is bent. The portion similarly moves in the pulling direction of the inner wire 59, so that the wire holder 61 is pushed out and the lever 55 is rotated in the same direction as above.

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

When the plunger 28 is rotated with the start of the engine 6, the cam surface 50 of the cylindrical cam 49 comes into sliding contact with the circumferential surface of the rotating shaft 48, so the plunger 28 reciprocates according to the shape of the cam surface 50. . In this case, when the plunger 28 is pushed out to the right in FIG. .42 is aligned with the suction port 44 + 44, and lubricating oil is sucked from the suction port 44.44. When the plunger 28 is pushed to the left side in FIG. 5 based on the shape of the cam surface 50 due to the rotation of the plunger 28, the internal volumes of the first pump chamber 35 and the second pump chamber 38 are reduced. At the same time, the discharge switching port 41.43 comes into contact with one of the discharge ports 45.45, and the pressurized lubricating oil flows through the discharge port 45.45 and the discharge passage 47.4 connected thereto.
7 and is supplied to each lubricating part of the engine 6. In addition, such a discharge operation is performed when the discharge ports 45 and 45 face each other,
In other words, since they are provided with a phase difference of 180°, the rotation is performed twice during one rotation of the plunger 28.

Therefore, the amount of lubricating oil discharged from the plunger 28 is
Since it is determined by the reciprocating stroke amount of Being manipulated. In this state, the cam surface 54 of the recess 53 and the protrusion 52 are in the closest positional relationship, so that as the plunger 28 rotates, the trough of the cam surface 50 of the cylindrical cam 49 moves toward the rotation shaft 48.
The protrusion 52 and the recess 53 come into contact before sliding into contact with each other.

Therefore, the apparent lift amount of the main cylindrical cam 49 is reduced, so that the stroke of the plunger 28 is shortened and the amount of lubricating oil discharged is also reduced. In such a low rotation range, when the throttle 56 is fully opened or the throttle opening is set to 171 as the load on the engine 6 increases, the rotating shaft 4 is
8 is rotated in the opening direction, and the protrusion 52 and the recess 53 are separated from the above position. Therefore, the sliding range of the rotating shaft 48 with respect to the cam surface 50 becomes longer, so as shown in FIG. 9, the stroke of the plunger 28 increases and the amount of lubricating oil discharged also increases. During operation, when the engine 60 rotation speed exceeds 5000 (rpm) and reaches a medium-high speed rotation range, the pulley 20 is rotated by the servo motor 19, so the exhaust pulp 13 begins to open, and the exhaust timing is accelerated. Furthermore, since the operation wire 57 is deformed by the rotation of the pulley 20 and the lever 55 is rotated in the direction of opening, the sliding range of the rotation shaft 48 with respect to the cam surface 50 becomes longer.
The stroke also increases, and as is clear from FIG. 9, the amount of lubricating oil discharged increases rapidly at 5000 (rpm).

Furthermore, even if the engine 6 is in a high rotational speed range and the throttle 56 is tightened to 9, for example, and the operating state shifts to low load and high rotational speed, the rotational speed will be 5000 (
rpm), the rotating shaft 48 continues to be rotated in the opening direction via the operating wire 57 and the lever 55 that are interlocked with the pulley 20 for driving the exhaust valve 13, so the amount of lubricating oil discharged is reduced accordingly. Can be many.

According to such an oil pump 25, the plunger 28
The stroke of
Since the adjustment control is performed according to the rotational speed of the engine 6, when the rotational speed of the engine 6 is in a high rotational speed range, the discharge amount of lubricating oil can be increased along with the opening degree of the throttle 56. For this reason, the discharge amount of lubricating oil is
The required amount can be appropriately adjusted and controlled according to the operating conditions of the engine 6, and the reliability of lubrication is significantly improved.

L=”4- also eliminates the need to set the oil discharge amount to a large amount according to the required amount in the high speed range in order to compensate for the lack of oil in the medium and high speed range as in the past, υ, therefore, the low speed The amount of oil discharged in the area can be reduced to an amount commensurate with the rotation, making it possible to reduce oil consumption and exhaust smoke.

1. In the above-mentioned embodiment, the rotating shaft was opened and closed by power transmission from the exhaust pulp drive pulley, but for example, a dedicated motor for operating the rotating shaft may be provided, and this motor may be operated according to the engine speed. The rotation shaft may be opened and opened by controlling the rotation shaft.

Further, the engine according to the present invention is not limited to a two-stroke engine, but may be a rotary engine.

〔Effect of the invention〕

According to the present invention described in detail above, it is possible to adjust and control the oil discharge amount to the required oil amount corresponding to the operating conditions of the engine.Therefore, the reliability of lubrication is improved, and the entire rotation range of the engine is improved. (Since it is no longer necessary to set the oil discharge amount to a large value, it is possible to reduce the amount of oil consumed.

[Brief explanation of the drawing]

The drawings illustrate one embodiment of the present invention.1. Figure 1 is a side view of the front rotor of a motorcycle, Figure 2 is a sectional view of the engine,
Figure 3 is a block diagram showing the control system of the exhaust valve, Figure 4
The figure is a block diagram showing the control system of the oil pump and exhaust valve, Figure 5 is a sectional view taken along line V-V in Figure 4, Figure 6 is a sectional view taken along line VI-IT in Figure 5, and Figure 6 is a sectional view taken along line VI-IT in Figure 5. 7 is a cross-sectional view taken along the line ■-■ in FIG. 4, FIG. 8 is an explanatory diagram of the operation, and FIG. 9 is a characteristic diagram. 6...Engine, 26...Pump case, 28...
・Plunger, 48...Rotating member (rotating shaft), 49・
...Cylindrical cam, 50...Cam surface, 52.53...Contact part (protrusion, four parts) 0 Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Supplement to the procedure 1M (7n 51Bj, '-,' Month 10 11 Kazuo Wakasugi, Commissioner of the Japan Patent Office, 1, Indication of the case, Japanese Patent Application No. 58-200500, 2, Name of the invention, Molecule i Oil pump for refueling type engine, 3, Amendment. Relationship with the case filed by the person who filed the patent application Patent applicant (AO7) Yamaha Motor Co., Ltd. 4, Agent 6 Specification subject to amendment, drawing 7, content of amendment (1) Line 3 of Liang 7-2-J in the specification (2. It says "Worm gear 31". Correct it as "Worm wheel 31.") 12) In the fifth line of page 7 of the specification, "Worm wheel 32" should be corrected as "Worm 32." (31 Add the leader line number 14 to box 4 of the drawing attached to the application as if it were not placed in the attached drawing. (4) Add the leader line number 14 in box 5 of the same drawing to figure 4 of the attached drawing. (51) The code 4o in box 6 of the same drawing has been corrected to 43, as it was not placed in the attached drawing, and the code 43 in Fig. 6 has also been corrected, as it was not placed in the attached drawing. Correct the code to 40. (6) Correct box 9 in the same drawing as shown in the attached sheet. 2-

Claims (1)

[Claims] A plunger that is rotationally driven by power transmission from the engine is rotatably housed in the pump case, and
A cylindrical cam is provided at one end of this plunger, and by rotating this plunger, the plunger is reciprocated in the axial direction with a predetermined stroke according to the shape of the cam surface of the cylindrical cam, and the stroke amount of this plunger is In an oil pump that discharges a corresponding amount of oil, a rotary member is provided in the pump case to be reciprocated by a predetermined angle in conjunction with the load and rotational speed of the engine, and this rotary member is connected to the cam of the plunger. In addition to making sliding contact with the cam surface, the mutually opposing portions of the rotating member and the plunger are moved toward and away from each other according to the rotation angle of the rotating member to form a sliding contact range along the circumferential direction of the rotating member with respect to the cam surface. An oil pump with two separate lubrication systems characterized by having a contact part that changes the oil.