JP2850130B2 - Lubricating device for two-cycle engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lubricating device for supplying lubricating oil to a two-stroke engine.

(Prior Art) A two-stroke engine is generally provided with a lubricating device for lubricating a sliding contact portion between a syringe hole and a piston, and this device generally includes an oil pump interlocked with a crankshaft. The oil pump supplies lubricating oil to the engine according to the number of revolutions of the engine.

Further, in the above configuration, the supply amount of the lubricating oil needs to be increased when the engine is in the high load region even at the same rotational speed, and conversely, when the engine is in the low load region, the supply amount is small. Is known to be sufficient. That is, the discharge amount of the oil pump per one revolution of the engine is increased in a high load region, and is decreased in a low load region.
Since the discharge amount per one revolution of the engine corresponds to the stroke of the oil pump, the oil pump is linked to the operating means of the carburetor, and the stroke of the oil pump is increased or decreased in accordance with the throttle opening of the carburetor. Some devices are provided with adjusting means (for example, see Japanese Patent Application Laid-Open No. 57-143117).
Reference).

By the way, in this device, the stroke of the oil pump is constant at a constant throttle opening, so that the discharge amount of the oil pump increases linearly in proportion to the engine speed, and increases as the throttle opening increases. Incline increases. The supply amount of the lubricating oil at the time of maximum rotation is the maximum at each throttle opening. However, if the supply amount is optimally set at this point, there is a disadvantage that the supply becomes excessive in the low speed range.

As a countermeasure, a cam that rotates together is fixed to a reciprocating plunger, the cam is provided with a cam surface having irregularities on the circumference, and is provided so as to intersect the cam surface at a right angle and has a diameter of two stages, large and small. The operating pin protrudes into the cam surface and engages with the cam, causing the plunger to stroke and, at a certain rotational speed during the transition from the high-speed region to the low-speed region, the electromagnet causes the large-diameter to small-diameter pin to engage with the cam surface. In order to reduce the discharge amount of the oil pump per one revolution of the engine, it has been proposed to reduce the stroke of the oil pump (see, for example, JP-A-63-55313).

(Problems to be Solved by the Invention) However, in the above configuration, the stroke of the oil pump changes in two stages at a certain rotation speed. On the high side near the number, the lubricating oil becomes excessive, and on the low side, the lubricating oil becomes too small. In this device, it is structurally difficult to make the diameter of the operating pin several steps to reduce the stepwise change.

Further, in a small displacement engine, when the throttle opening is small in a low speed range, the supply amount of the lubricating oil per one revolution of the engine is extremely small, so that the stroke of the oil pump is also small. However, it is impossible to avoid minute leakage of the lubricating oil from the pump chamber in terms of machining accuracy, so that it becomes difficult to accurately adjust the discharge amount when the stroke of the pump is reduced.

Furthermore, since the operating pin projects perpendicularly from the outer peripheral side of the cam to the cam surface, the tip of the pin may collide with the outer periphery of the cam, causing loss or wear, and an electromagnet for operating the pin is provided at right angles to the plunger shaft. Therefore, there is a problem that the electromagnet protrudes to the side and hinders downsizing of the device.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and in a case where a regulating means for regulating the supply of lubricating oil to the engine is provided, the engine has a small displacement in a low speed range. At one time, in order to prevent unnecessary supply of lubricating oil to the engine, and to arrange a combination of an oil pump and a regulating means for this purpose around the engine in a narrow space, The purpose is to make it easy.

In addition, when sufficient lubricating oil supply to the engine in a high-speed, high-load range is ensured, and lubricating oil supply in a low-speed range is not excessive, it is desirable that the lubricating oil be supplied at each engine speed. It is an object of the present invention to be able to supply a quantity of lubricating oil with higher accuracy.

(Constitution of the Invention) The feature of the present invention that achieves the above object is as follows.
The oil pump 3 has a casing 5 and a rotating shaft 7 having a bottomed plunger hole 11 and supported in the casing so as to be rotatable around its axis. A plunger 13 inserted into the plunger hole so as to be slidable, a pump chamber 14 formed by being surrounded by an inner bottom surface of the plunger hole and a fitting end of the plunger, and an axial direction of the rotation shaft. A cam surface 21, which is formed on one end surface and alternately has a convex surface 22 and a concave surface 23 in its circumferential direction, a cam shaft 24 attached to the casing or plunger, and the cam surface and cam shaft attached to the casing side A spring 25 for urging the rotation shaft to engage with the rotation shaft so that the rotation shaft rotates in proportion to the number of revolutions of the engine 1. The cam engagement during rotation of the rotation shaft causes the rotation shaft and the plunger to rotate. And The pump chamber moves relatively in the axial direction, and the pump chamber alternately expands and contracts, the lubricating oil in the pump chamber discharges toward the engine, and the oil pump per one rotation of the engine in a predetermined rotation range of the engine. In a lubricating device for a two-stroke engine provided with a regulating means 37 for regulating a discharge amount, 1) a cylinder in which the regulating means is arranged at one end of a casing coaxially with the rotating shaft and excitation and demagnetization are alternately repeated; A magnet-like electromagnet 38, wherein the excitation force of the electromagnet causes the attraction force to act in the opposite direction against the urging force of the spring, thereby moving the rotary shaft or plunger in the axial direction to release the cam engagement. (2) A control circuit 43 for controlling the cycle of excitation and demagnetization and the ratio of excitation time to demagnetization time is connected to the electromagnet so that the discharge amount of the oil pump can be adjusted in a continuous curve.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show a first embodiment.

In FIG. 1, reference numeral 1 denotes a two-stroke engine mounted on a motorcycle. This engine 1 has an intake passage 1a and a carburetor 1b. An oil tank 2 is provided with an oil pump 3 for supplying lubricating oil in the oil tank 2 to the engine 1 through an intake passage 1a.

The oil pump 3 has a casing 5, and the casing 5 has a left-right direction (a direction toward the drawing,
A hole 6 having a circular cross section is formed.
A rotary shaft 7 that rotates around the axis of the hole 6 is fitted into the hole 6. The rotating shaft 7 is linked to the pump driving shaft 8 of the engine 1 via a worm gear 9 so that the rotating shaft 7 rotates in proportion to the rotation speed of the engine 1.

A plunger hole 11 is formed on the axis of the rotary shaft 7. A left end of the plunger hole 11 is closed by a stopper 12, and a plunger 13 is slidably fitted in the right end side in the axial direction, and is surrounded by the stopper 12 and the left end of the plunger 13 in the plunger hole 11. Is a pump chamber 14.

The casing 5 is provided with holes 6 outside the casing 5.
An oil supply hole 16 communicating with the inside of the oil supply hole is formed, and the oil tank 2 is connected to the oil supply hole 16. Also,
The rotary shaft 7 is formed with an oil hole 17 for communicating the pump chamber 14 to the outside of the rotary shaft 7.
Is formed with an oil discharge hole 18 for communicating the inside of the hole 6 to the outside of the casing 5. Also, this oil discharge hole 18
Is provided with a one-way valve 19 that allows the flow of the lubricating oil only from the hole 6 side to the outside of the casing 5, and the outlet side of the one-way valve 19 is connected to the intake passage 1 a of the engine 1. .

When the rotary shaft 7 rotates about its axis, the oil hole 17 intermittently matches the oil supply hole 16 and the oil discharge hole 18, and the oil hole 17 is in contact with the oil supply hole 16. Discharge hole
When one of the holes 18 coincides with the other, the other hole is closed on the outer peripheral surface of the rotating shaft 7.

A cam surface 21 is formed on the right end surface of the rotating shaft 7, and the cam surface 21 has convex surfaces 22 and concave surfaces 23 alternately in the circumferential direction. On the other hand, the plunger 13 is provided with a cam shaft 24 which is engaged with the cam surface 21 in the radial direction.
A spring 25 urges the plunger 13 to the left such that 24 joins the cam surface 21.

The rotation of the pump drive shaft 8 causes the worm gear 9 to rotate.
When the rotary shaft 7 is rotated via the rotary shaft 7, when the oil hole 17 matches the oil supply hole 16, the cam shaft 24 is pushed by the convex surface 22 and the plunger 13 moves rightward.
Therefore, at this time, the pump chamber 14 is enlarged, and the lubricating oil in the oil tank 2 is sucked into the pump chamber 14 through the oil supply holes 16 and the oil holes 17. Further, when the rotary shaft 7 rotates and the oil hole 17 coincides with the oil discharge hole 18 as shown, the cam shaft 24 corresponds to the concave surface 23 and the plunger 13
To move to the left. And
At this time, the pump chamber 14 is reduced,
Lubricating oil in the oil hole 17, oil discharge hole 18, and one-way valve
It is discharged through 19 and supplied to the engine 1.

Hereinafter, as described above, the oil hole 17
Are intermittently coincident with the oil supply hole 16 and the oil discharge hole 18 sequentially, and at the same time, the plunger 13 repeats reciprocating movement to the left and right, so that the lubricating oil is supplied to the engine 1 quantitatively. Becomes

In the oil pump 3 having the above configuration, an adjusting means 27 for increasing or decreasing the discharge amount of the oil pump 3 in accordance with the throttle opening of the carburetor 1b is provided.

The adjusting means 27 will be described.
At the right end of 13, a disk 28 is screwed. on the other hand,
A pulley 29 is rotatably fitted on the right end of the casing 5 coaxially with the plunger 13.
Urged to the right. A cam surface 32 is formed in the boss portion of the pulley 29 in a spiral shape in the circumferential direction, and a stopper 33 which engages with the cam so that the cam surface 32 is in sliding contact with the cam surface 32 is screwed to the casing 5. .

When the pulley 29 is rotated around its axis, the cam surface 32 which rotates together with the pulley 29 is cam-engaged with the stopper 33 so that the pulley 29 moves in the left-right axial direction.

The right end surface of the boss of the pulley 29 is the stopper surface.
The left surface of the disk 28 corresponds to the stopper surface 34. If the pulley 29 is moved rightward by the rotation of the pulley 29, that is, if the disc 28 is brought into contact with the stopper surface 34 while the plunger 13 is moving leftward by the spring 25, the plunger 13 , The stroke of the reciprocating motion of the oil pump 3 is shortened, so that the discharge amount of the oil pump 3 is suppressed.

An operating wire 36 is connected to the pulley 29, and the wire 36 is operatively connected to operating means (not shown) for adjusting the throttle opening of the carburetor 1b. When the throttle opening is increased, the pulley 29 rotates, and the cam surface against the stopper 33 at this time is rotated.
The pulley 29 moves to the left due to the engagement of the cam 32 and the disk 28
The stopper surface 34 is separated from the contact. That is,
At this time, the stroke of the plunger 13 becomes longer, and the discharge amount of the oil pump 3 increases.

On the other hand, when the throttle opening is reduced, the pulley 29 is moved rightward by the rotation of the pulley 29 opposite to the above, so that the stopper surface 34 approaches the disk 28. That is, at this time, the stroke of the plunger 13 is shortened, and the discharge amount of the oil pump 3 is reduced.

The adjusting means 27 is not essential to the present invention, and may not be provided.

In the oil pump 3 having the above-described structure, when the engine 1 is in the low-speed range, a regulating means 37 is provided to regulate the operation of the oil pump 3 to reduce the discharge amount.

The control means 37 will be described.
Is a magnetic material, and an electromagnet 38
The electromagnet 38 is screwed to the casing 5 by bolts 39. The electromagnet 38 includes an iron core 41 and a coil 42, and the coil 42 is connected to a control circuit 43.

The control circuit 43 inputs the number of revolutions of the engine 1 and stops the energization of the coil 42 to demagnetize the iron core 41 in the high-speed rotation range.
To excite the iron core 41, and the disk 28 is magnetically attached to the iron core 41. That is, at this time, the cam shaft 24 is
The plunger 13 does not operate even if the rotary shaft 7 rotates to the right away from the engine 1. In this case, the lubricating oil is not supplied to the engine 1.

Further, in the above case, the electromagnet 38 operates at its demagnetization time (TOF
F) and the excitation time (TON) are controlled by the control circuit 43 so as to be alternately repeated in short cycles. The number of cycles per unit time and the ratio (R) of the two times are controlled by the control circuit 43 to a desired value. Can be adjusted.

Here, assuming that the discharge amount when the oil pump 3 is continuously operated is V0, the discharge amount V of the oil pump 3 controlled as described above is expressed by the following equation.

And if, for example, R = TOFF: TON = 1: 9, Becomes

Therefore, when the required supply amount of the lubricating oil at the maximum number of revolutions is secured and the engine 1 becomes slow, the amount of the lubricating oil supplied to the engine 1 is set to an appropriate one-tenth that of the conventional case. The amount can be reduced.

FIG. 2 is a graph showing the above-mentioned operation, and the phantom line indicates a conventional example in which the discharge amount of the oil pump 3 at a certain throttle opening is linearly proportional to the rotation speed of the engine 1, A broken line indicates a desired discharge amount according to the rotation speed of the engine 1. When the oil pump 3 is operated as in the above example, the plunger 13 operates normally in the high-speed range (H) as shown by the solid line, and the discharge amount of the oil pump 3 matches the desired discharge amount. However, in the low speed range (L), the operation of the plunger 13 is regulated by the regulating means 37, and the discharge amount is reduced so as to approach a desired discharge amount. It is done so as not to be excessive.

This means that the low-speed range (L) is divided into three stages of first, second, and third low-speed ranges (L1.L2, L3) sequentially from the side near the high-speed range (H).
The ratio at each stage is, for example, R1 = 1: 2, R2 = 1:
4. This is a case where the control circuit 43 is configured to increase sequentially as R3 = 1: 9. By doing so, the discharge amount of the oil pump 3 is made as close as possible to the desired non-straight discharge amount. Since the rotation ranges L1 to L3 are set by the control circuit, it is naturally possible to extend the rotation range to a high-speed range, and further divide each rotation range further to increase the number thereof. Can be adjusted in a continuous curve with small steps.

In the case of the above configuration, even if a failure occurs in the electric system with respect to the regulating means 37, the oil pump 3 operates continuously, so that the reliability of the supply of the lubricating oil to the engine 1 is maintained.

Although the above description is based on the illustrated example, instead of controlling the oil pump 3 by the adjusting means 27 linked to the throttle opening, the electromagnet 38 is controlled by the rotation speed of the engine 1 and the throttle opening of the carburetor 1b. The control circuit 43 may be configured so that the ratio (R) between the demagnetization time and the excitation time is controlled in a map or in an analog manner by calculation.

Each of the following drawings shows another embodiment in which the adjusting means 27 is removed. Since the basic configurations and operations of the engine 1, the oil tank 2, the oil pump 3, and the control circuit 43 in these embodiments are the same, common components are denoted by reference numerals, and description thereof is omitted, and different configurations are provided. Will be described.

(Second Embodiment) FIGS. 3 to 10 show a second embodiment.

3 to 5, at the right end of the rotating shaft 7, a plunger hole 11 having a bottom is formed on the axis thereof, and a plunger 13 is fitted into the plunger hole 11, and the plunger 13 is inserted into the plunger hole 11. The space closed by the pump room
It is 14. Further, first and second oil absorption holes 51 and 52 are formed, one end of which opens into the pump chamber 14 and the other end of which opens on the outer peripheral surface of the rotary shaft 7. Is formed. Further, a pressure oil hole 53 is formed adjacent to the right side of the above 51, and one end of the pressure oil hole 53 is also formed in the pump chamber 14.
And the other end is opened on the outer peripheral surface of the rotating shaft 7.

On the other hand, an oil supply hole 54 is formed in the casing 5,
One end of the oil supply hole 54 is connected to the oil tank 2, and the other end communicates with a gap in the tooth portion of the worm gear 9. An oil supply groove 55 is formed on the inner peripheral surface of the hole 6 along the axial direction of the hole 6, and one end of the oil supply groove 55 extends to the gap between the teeth of the worm gear 9. .

Further, the casing 5 has first and second oil discharge holes 56 and 5 for communicating the inside of the hole 6 to the outside of the casing 5.
7 are formed at radially symmetric positions of the hole 6 and are formed at positions deviated from the oil supply groove 55 by about 90 ° in the circumferential direction of the hole 6.

A cam surface 21 is formed on the left end surface of the rotary shaft 7, and a cam shaft 24 that is cam-engaged with the cam surface 21 is attached to the casing 5. A spring 25 is provided to urge the rotating shaft 7 to the left so that the cam surface 21 is joined to the cam shaft 24, and to urge the plunger 13 to the right.
Is pressed against the inner surface of the cover body 59 in which the right end of the hole 6 is closed, and further movement to the right is prevented.

The rotation of the pump drive shaft 8 causes the worm gear 9 to rotate.
In the case where the rotary shaft 7 is rotated via the shaft (shown by an arrow R in FIG. 5), as shown in FIGS. The concave surface 23 is engaged with the shaft 24, and the rotating shaft 7 is pushed by the spring 25 and moves to the left. Therefore, at this time, the pump chamber 14 is enlarged, and the oil supply holes 54,
The lubricating oil in the oil tank 2 is sucked through the oil supply groove 55 and the first oil suction hole 51. At this time, as shown in FIGS. 3 to 5, the pressure oil hole 53 also matches the oil supply groove 55. Therefore, the pump chamber 14 is lubricated even through the pressure oil hole 53. Oil is inhaled.

As shown in FIG. 6 and FIG. 7, when the rotating shaft 7 further rotates by about 90 ° from the above state, the first oil absorbing hole 51 and the second oil absorbing hole 51
The oil absorption hole 52 is closed by the inner peripheral surface of the hole 6, while the pressure oil hole 53 opens toward the first oil discharge hole 56. In this case, the convex surface 22 is engaged with the cam shaft 24,
The rotation shaft 7 moves rightward against the spring 25.

Therefore, at this time, the pump chamber 14 is reduced, and the lubricating oil in the pump chamber 14 is discharged through the pressure oil hole 53 and the first oil discharge hole 56, and is supplied to the engine 1.

As shown in FIG. 8, when the rotating shaft 7 is further rotated by about 90 ° from the above state, the second oil absorbing hole 52 matches the oil supply groove 55, and at this time, the concave surface 23 engages with the cam shaft 24. Therefore, the pump chamber 14 is enlarged again, and the lubricating oil of the oil tank 2 is sucked into the pump chamber 14 through the oil supply hole 54, the oil supply groove 55, and the second oil suction hole 52. .

Further, as shown in FIG. 9, when the rotating shaft 7 rotates about 90 ° from the above state, the first oil absorbing hole 51 and the second oil absorbing hole 52 are closed by the inner peripheral surface of the hole 6 while the pressure oil hole is closed. 53 opens toward the second oil discharge hole 57, in which case the cam shaft 24 has a convex surface.
22 are to be engaged. Therefore, the pump chamber 14
Therefore, the lubricating oil in the pump chamber 14 is discharged through the pressure oil hole 53 and the second oil discharge hole 57, and is supplied to the engine 1.

Thereafter, when the rotating shaft 7 further rotates, the state returns to the state shown in FIG. 3 to FIG. 5, and thereafter, the above-described operation is repeated, and the lubricating oil is supplied to the engine 1.

In the above case, if the engine 1 is a two-cylinder engine, the first oil discharge hole 56 is connected to one of the syringes, and the second oil discharge hole 56
57 may be linked to the other syringe.

Regulation means 37 provided in oil pump 3 having the above configuration
Is a disk 60 magnetically attached to the electromagnet 38 and this disk
And a push rod 61 protruding from 60 toward the center of the left end of the rotating shaft 7. The restricting means 37 is housed inside the casing 5 through an opening 58 on the left side of the casing 5 with the disc 60 and the push rod 61 incorporated in the electromagnet 38, and the opening 58 is closed by a cover plate 62.

In FIG. 10, the electromagnet 38 is excited by the control circuit 43 in the low-speed rotation range of the engine 1. Then, the disk 60 magnetically attaches to the electromagnet 38 and moves rightward, and the push rod 61 accompanying the disk 60 pushes the rotating shaft 7 rightward against the spring 25, and the cam surface 21 is moved to the camshaft 24. It is designed to be pulled away from. In this case, even if the rotating shaft 7 rotates, the pump chamber 14 does not expand or contract, that is, the lubricating oil is not supplied to the engine 1.

(Third Embodiment) FIGS. 11 to 18 show a third embodiment.

Since the basic configuration of the oil pump 3 in this embodiment is the same as that of the second embodiment, the common components are denoted by the reference numerals, and description thereof will be omitted, and different configurations will be described.

11 to 13, a plunger hole 11 is formed on the axis of the rotating shaft 7, and the right end of the plunger hole 11 is closed by a stopper 12. A plunger 13 is fitted on the left end side of the plunger hole 11, and a plug is inserted in the plunger hole 11.
The space surrounded by 12 and the right end of plunger 13 is pump chamber 14
It has become. An oil-absorbing hole 63 having one end opened in the pump chamber 14 and the other end opened in the outer peripheral surface of the rotary shaft 7 is formed. In addition, first and second oil supply grooves 64 and 65 are formed on the inner peripheral surface of the hole 6 along the axial direction of the hole 6, and these are formed at radially symmetric positions of the hole 6. Each of these ends communicates with the oil supply hole 54 through a gap between the teeth of the worm gear 9.

A cam surface 21 is formed on the right end surface of the rotating shaft 7,
The camshaft 24 that engages with the cam 21 is attached to the cover body 59. A spring 25 is provided to urge the rotating shaft 7 to the right so that the cam surface 21 is joined to the cam shaft 24, while urging the plunger 13 to the left. The left end of the plunger 13 is To prevent further movement to the left. Note that a metal pad 66 of high hardness and wear resistance is embedded in a portion where the left end of the plunger 13 is pressed against the iron core 41.

When the rotation shaft 7 rotates, the eleventh
As shown in FIG. 13 to FIG. 13, the oil absorption hole 63 is formed in the first oil supply groove 64.
, The concave surface 23 is engaged with the cam shaft 24, and the rotary shaft 7 is pushed by the spring 25 and moves rightward. Therefore, at this time, the pump chamber 14 is enlarged,
The lubricating oil in the oil tank 2 is sucked into the pump chamber 14 through the oil supply hole 54, the first oil supply groove 64, and the oil suction hole 63.

As shown in FIGS. 14 and 15, when the rotating shaft 7 further rotates by about 90 ° from the above state, the oil absorbing hole 63 becomes the first state.
It opens toward the oil discharge hole 56. At this time, the convex surface 22 is engaged with the cam shaft 24, and the rotating shaft 7 moves leftward against the spring 25.

Therefore, at this time, the pump chamber 14 is reduced, and the lubricating oil in the pump chamber 14 is discharged through the oil suction hole 63 and the first oil discharge hole 56, and is supplied to the engine 1.

As shown in FIG. 16, when the rotating shaft 7 further rotates by about 90 ° from the above state, the oil suction hole 63 matches the second oil supply groove 65, and at this time, the concave surface 23 engages with the cam shaft 24. Therefore, the pump chamber 14 is enlarged again, and the lubricating oil of the oil tank 2 is sucked into the pump chamber 14 through the oil supply hole 54, the second oil supply groove 65, and the oil suction hole 63. .

Further, as shown in FIG. 17, when the rotating shaft 7 rotates about 90 ° from the above state, the oil suction hole 63 opens toward the second oil discharge hole 57, and at this time, the camshaft 24 Are adapted to engage. For this reason, the pump chamber 14 is reduced, so that the lubricating oil in the pump chamber 14 is discharged through the oil suction hole 63 and the second oil discharge hole 57, and is supplied to the engine 1.

Hereinafter, the rotation of the rotating shaft 7 further returns to the state shown in FIG. 11 to FIG. 13, and thereafter, the above-described operation is repeated, and the lubricating oil is supplied to the engine 1.

In FIG. 18, a regulating means 37 provided in the oil pump 3 having the above-described structure is the electromagnet 38 itself,
When this electromagnet 38 is excited by 43, this electromagnet 38
The rotation shaft 7 is magnetically attached to 38 and moves leftward, whereby the cam surface 21 is separated from the cam shaft 24. In this case, even if the rotating shaft 7 rotates, the pump chamber 14 does not expand or contract, that is, the engine 1 is not supplied with lubricating oil.

The regulating means 37 is provided at the left opening 58 of the casing 5.
In this case, the restricting means 37 closes the opening 58. That is, the restricting means 37 also has a function as the cover plate 62 in the second embodiment. The left end side of the regulating means 37 is exposed to the outside, and an insertion portion 67 of an electric path to the electromagnet 38 is provided here.

According to the configuration of the above embodiment, the following points are excellent as compared with the second embodiment. That is, in the second embodiment, the regulating means 37
Is inserted into the casing 5 and closed by the cover plate 62, so that it is difficult to seal the insertion portion 67 of the electric path for supplying electric power to the electromagnet 38. On the other hand, the regulating means 37 of the third embodiment is difficult. Is partially exposed to the outside, so that it is not necessary to consider the sealing property of the insertion portion 67 of the electric circuit, and there is an advantage that the configuration is simplified accordingly.

(Effect of the Invention) According to the present invention, the oil pump is provided with a casing,
A rotating shaft that has a bottomed plunger hole and is supported in the casing so as to be rotatable around its axis, and the plunger hole is relatively slidable in the axial direction with the rotating shaft. A plunger to be fitted, a pump chamber formed by being surrounded by an inner bottom surface of the plunger hole and a fitting end of the plunger, and a convex surface and a concave surface formed on one end surface in the axial direction of the rotating shaft and having a circumferential direction. A cam surface having alternating
A camshaft attached to the casing or the plunger; and a spring attached to the casing side for urging the cam surface and the camshaft to engage with the cam, wherein the rotating shaft is proportional to the engine speed. The rotating shaft and the plunger are relatively moved in the axial direction by the cam engagement at the time of rotation of the rotating shaft, so that the pump chamber alternately expands and contracts, and the pump chamber is closed. In a lubricating device for a two-stroke engine, wherein lubricating oil is discharged toward an engine, and a restricting means for restricting a discharge amount of an oil pump per one revolution of the engine at a predetermined rotational speed of the engine is provided. A cylindrical electromagnet arranged coaxially at one end of the casing and energized and demagnetized alternately and repeatedly, and the energization of the electromagnet opposes the attraction force against the urging force of the spring. Direction, and move the rotary shaft or plunger in the axial direction to disengage the cam, and connect a control circuit to the electromagnet to control the cycle of excitation and demagnetization and the ratio of excitation time to demagnetization time to the electromagnet. Since the discharge amount can be adjusted in a continuous curve, the following effects are obtained.

The discharge amount of the oil pump does not change to a large step at a certain rotation speed, and the supply amount of the lubricating oil does not become excessively small or small before and after this rotation speed.

In general, in a small displacement engine, when the throttle opening is small in a low speed range, the supply amount of the lubricating oil is extremely small, and accordingly, the stroke of the oil pump becomes small, so that it becomes difficult to adjust the discharge amount. According to the present invention, the operation of the pump is intermittently stopped to adjust the discharge amount, so that even a small amount close to 0 can supply the lubricating oil stably. By setting the amount to 0, unnecessary supply of lubricating oil can also be prevented.

Further, since the cam shaft comes into contact with the cam surface from the front of the cam surface, the cam shaft does not break or wear even if the contact and the separation are repeated by the electromagnet.

In addition, since the electromagnet is provided coaxially with the rotating shaft at one end of the casing, the electromagnet is compact without protruding to the side, and a mechanism that mechanically changes the stroke of the oil pump in conjunction with the throttle opening in the past. The oil pump can be removed and the operation can be controlled by a control circuit so that the electromagnet performs the operation, so that the configuration of the oil pump can be simplified.

Furthermore, even if a failure occurs in the electric system of the regulating means and the electromagnet is no longer excited, the spring continues to engage the cam shaft and the cam surface, so that the pump continues its stroke, and the safety against the supply of lubricating oil is maintained. Can be secured.

[Brief description of the drawings]

1 and 2 show a first embodiment, FIG. 1 is a longitudinal sectional view, FIG. 2 is a graph showing various control results, and FIGS. FIG. 3 is a plan view, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG. 5 is a sectional view taken along line VV of FIG. , FIG. 6 is a view corresponding to FIG. 3 and FIG. 3 is an explanatory view of the operation, FIGS. 7 to 9 are partial views of FIG. 5 and are action explanatory views, and FIG. 10 is a view corresponding to FIG. FIGS. 11 to 18 show a third embodiment, FIG. 11 is a plan view, and FIG.
12 is a sectional view taken along the line XII-XII of FIG. 11, and FIG.
FIG. 11 is a sectional view taken along the line XIII-XIII of FIG. 11, FIG. 14 is a view corresponding to FIG. 11, and FIG. 15 is an explanatory view of the operation, and FIG. 15 to FIG. 17 are partial explanatory views of FIG. FIG. 18 is a diagram corresponding to FIG. DESCRIPTION OF SYMBOLS 1 ... Engine, 3 ... Oil pump, 5 ... Casing, 7 ... Rotary shaft, 11 ... Plunger hole, 13 ... Plunger, 14 ... Pump chamber, 21 ... Cam surface, 22 ... Convex surface, twenty three
…… Concave surface, 24… Cam shaft, 25… Spring, 38… Electromagnet,
43 Control circuit.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-55313 (JP, A) JP-A-61-46409 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F01M 1/16 F01M 3/00

Claims (1)

(57) [Claims] An oil pump having a plunger hole having a bottom and a rotating shaft supported in the casing so as to be rotatable around the axis thereof; A plunger fitted into the plunger hole so as to be able to slide freely, a pump chamber formed by an inner bottom surface of the plunger hole, and a fitting end of the plunger; A cam surface formed on an end surface and having a convex surface and a concave surface alternately in the circumferential direction, a cam shaft attached to the casing or the plunger,
A spring attached to the casing and biasing the cam surface and the camshaft to engage with each other, so that the rotating shaft rotates in proportion to the engine speed;
Due to the cam engagement at the time of rotation of the rotating shaft, the rotating shaft and the plunger relatively move in the axial direction, and the pump chamber alternately expands and contracts, and the lubricating oil in the pump chamber is directed to the engine. A two-cycle engine lubricating apparatus provided with a regulating means for regulating the discharge amount of the oil pump per one revolution of the engine at a predetermined number of revolutions of the engine. 1) The regulating means is coaxial with the rotating shaft. A cylindrical electromagnet disposed at one end of the casing in such a manner that excitation and demagnetization are alternately repeated, and the energization of the electromagnet causes the attraction force to act in the opposite direction against the urging force of the spring. Alternatively, the plunger is moved in the axial direction to release the cam engagement. 2) A control circuit for controlling the cycle of excitation and demagnetization and the ratio of the excitation time to the demagnetization time is connected to the electromagnet, Pump discharge amount continuous curve adjustable and lubricating device of a two-stroke engine.