JPH0619765Y2 - Engine oil supply - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention changes the valve opening / closing timing and the lift amount according to the operating state, and stops the operation of the valve.
The present invention relates to an oil supply device for an engine equipped with a hydraulic plunger mechanism that changes the operating characteristics of a valve.

[Conventional technology]

Conventionally, in a vehicle engine, a low-speed rocker arm and a high-speed rocker arm, which are respectively driven by a low-speed cam and a high-speed cam designed to have a longer valve opening period than the low-speed cam, are arranged side by side. The low-speed rocker arm is connected to the intake or exhaust valve, and both rocker arms are separably connected by the hydraulic plunger mechanism. While opening and closing the valve, at the time of high engine speed, by connecting both rocker arms to the high speed cam to open and close the valve, the period of valve opening at high speed is made longer than at low speed and at high speed. It has been proposed to increase the intake air charge (see Japanese Utility Model Laid-Open No. 61-58605).

Here, in the engine as described above, an example of an oil supply device in which low-speed rocker arms and high-speed rocker arms are provided in parallel on the intake side rocker shaft and only one type of rocker arm is provided on the exhaust side rocker shaft It is shown in FIG. The oil sucked by the oil pump 3 via the strainer 2 arranged in the oil pan 1 is sent via the regulator 4 and the oil filter 5 to the main gallery 6 which is an oil supply passage in the cylinder block. Lubricating oil is supplied to the crank journal portions 7a to 7d and the oil passages in the exhaust side rocker shaft 8 by a plurality of branch passages branched from the main gallery 6, and to the oil passages in the intake side rocker shaft 9. Oil for lubrication and for driving the hydraulic plunger mechanism is supplied.

By the way, in the hydraulic plunger mechanism, normally, the low speed and high speed rocker arms are switched from the separated state to the connected state by hydraulic pressure, while the switching from the connected state to the separated state is performed by a return spring. However, in order to obtain good switching performance, the set load of the return spring is usually about 1.8 kg / cm ² . In this case, considering variations in the set load of the return spring, etc., the hydraulic pressure required at the inlet of the oil passage in the intake side rocker shaft 9 for smoothly operating the hydraulic plunger mechanism is about 2.2 kg / cm ^2. Become.

[Problems to be solved by the device]

However, since the oil pressure of the oil supplied from the oil pan 1 decreases as the oil temperature rises, as shown by the broken lines A and B in FIG. 8, when the oil temperature is high, the actual intake-side rocker shaft 9 inside Required oil pressure at the oil passage inlet Oil pressure E (= 2.
2 kg / cm ² ) and the smooth operation of the hydraulic plunger mechanism was hindered. in this case,
In order to secure the required hydraulic pressure E at the inlet of the oil passage in the intake side rocker shaft 9, the pump capacity of the oil pump 3 may be increased. However, if the pump capacity of the oil pump 3 is increased, the pump resistance will increase. Will increase, resulting in a new inconvenience that the fuel efficiency will deteriorate. In FIG. 8, broken line A indicates the inlet oil pressure of the oil passage in the intake side rocker shaft 9 when the set pressure of the regulator 4 is 4 kg / cm ² , and broken line B indicates that the set pressure of the regulator 4 is 5 kg / cm ² . Oil pressure at the inlet of the oil passage in the intake side rocker shaft 9 at the time
Hydraulic, line D in the main gallery 6 when the set pressure of the regulator 4 is 4 kg / cm ² illustrates the oil pressure in the main gallery 6 when set pressure of the regulator 4 is 5 kg / cm ^2.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to secure a hydraulic pressure necessary for operating the hydraulic plunger mechanism even at a high temperature, and to cause a quick operation. An object of the present invention is to provide an oil supply device for an engine that can obtain various operating characteristics.

[Means for Solving the Problems]

In order to achieve the above object, the engine oil supply device according to the present invention is an engine oil supply device including a hydraulic plunger mechanism that changes valve operation characteristics. The first oil supply device supplies oil to a crank journal portion. A supply passage and a hydraulic adjustment valve provided in the first oil supply passage for suppressing the oil pressure of the oil supplied to the crank journal portion to a first set pressure, and from the first oil supply passage upstream of the hydraulic adjustment valve. A second oil supply passage that branches off and supplies oil to the hydraulic plunger mechanism is provided. In the second oil supply passage, an accumulator that temporarily stores oil and a switching unit that opens and closes the second oil supply passage are sequentially provided. A bypass passage is provided that supplies oil by bypassing the switching means from the accumulator to the hydraulic plunger mechanism. If, on the closing of the second oil supply passage by the switching means, to the pressure of oil supplied to the hydraulic plunger mechanism through the bypass passage is kept under a low second set pressure than the working pressure of the hydraulic plunger mechanism,
A relief valve for opening the valve to relieve oil when the second set pressure is exceeded is provided.

[Action]

According to the above configuration, the oil having the pressure suppressed by the hydraulic pressure adjusting valve to the predetermined first set pressure is supplied to the crank journal portion through the first oil supply passage. As described above, the oil supply pressure to the crank journal portion is suppressed, so that the oil is preferentially supplied to the hydraulic plunger mechanism. As a result, in the hydraulic plunger mechanism, the hydraulic pressure required for its operation is It can be sufficiently secured even when the oil temperature is high.

On the other hand, the hydraulic plunger mechanism is supplied with oil at a pressure equal to or higher than the working pressure of the hydraulic plunger mechanism from the accumulator through the second oil passage by opening the switching means when the engine is operating at a high rotation speed, for example. By closing the switching means at the time of low rotation, the oil retained by the relief valve below the second set pressure at which the hydraulic plunger mechanism does not operate at this time is supplied from the accumulator to the hydraulic plunger mechanism through the bypass passage.

As described above, even when the engine speed is low, the oil is supplied to the hydraulic plunger mechanism at the second set pressure or less, so that it is necessary to increase the supplied oil pressure. Is not normal pressure but pressure increase from the pressure state near the second set pressure to the working pressure,
This will be completed in a short time. As a result, the switching operation of the hydraulic plunger mechanism occurs quickly. Moreover, since the oil supply required for the above switching is supplied via the accumulator, the decrease in hydraulic pressure due to the amount of oil supplied to the hydraulic plunger mechanism during this switching operation can be suppressed to a minimum. Further, the switching operation will occur more quickly and reliably.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

The present embodiment relates to an oil supply device in a single overhead camshaft type multi-cylinder engine in which each cylinder is provided with two intake valves and one exhaust valve. As shown in FIG. 1, a strainer 12 is arranged in an oil pan 11 of the engine, and an oil pump 13 attached to the engine sucks oil in the oil pan 11 via the strainer 12.

The oil sucked by the oil pump 13 is adjusted to a predetermined pressure by the regulator 14, and then sent to the main gallery 17 in the cylinder block via the first oil supply passage 16 having the oil filter 15. A plurality of branch passages 18a to 18e branch from the main gallery 17, and a plurality of crank journal portions 20a to 20d in the cylinder block and an oil passage in the exhaust side rocker shaft 21 in the cylinder head through the respective branch passages 18a to 18e. Is configured to be supplied with lubricating oil. A hydraulic pressure adjusting valve 22 is arranged in the first oil supply passage 16 on the downstream side of the oil filter 15.
The oil pressure adjusting valve 22 sets the oil pressure of the oil supplied to the main gallery 17 via the first oil supply passage 16, in other words, the crank journal portions 20a to 20d and the oil passage in the exhaust side rocker shaft 21, to a set pressure, Specifically, the first set pressure is set as low as possible within a range that does not hinder the lubrication of the above parts.

The second oil supply passage 23 branches from the upstream side of the hydraulic pressure adjustment valve 22 in the first oil supply passage 16, and the second oil supply passage 23 is provided with an oil passage 51 in the intake side rocker shaft 25, which will be described later, via the hydraulic circuit 24. It is configured to supply oil to.

As shown in FIG. 2, the hydraulic circuit 24 is provided in the upstream portion 23a of the second oil supply passage 23, and temporarily supplies the operating oil to be supplied to the hydraulic plunger mechanism 43 described later on the intake side rocker shaft 25. An accumulator 26 for accumulating is provided. A spring 27 is provided in the accumulator 26.
Thus, the piston 28 biased downward in the drawing is slidably fitted. The upstream portion 2 of the second oil supply passage 23
The solenoid valve 29 is provided between the 3a and the downstream portion 23b.
Is provided with a plunger (switching means) 29a, and when the plunger 29a is located at the projecting position, the plunger 29a allows the upstream portion 23a and the downstream portion 23a.
When the plunger 29a is in the retracted position while the second oil supply passage 23 is closed due to the disconnection of the second oil supply passage 23, the upstream portion 23a and the downstream portion 23b communicate with each other and the second oil The supply passage 23 is configured to be open.

The accumulator 26 and the downstream portion 23b of the second oil supply passage 23 are communicated with each other by a bypass passage 31 having a smaller passage diameter than the second oil supply passage 23. A return passage 30 is further connected between the upstream portion 23a and the downstream portion 23b in the vicinity of the position where the plunger 29a is disposed. The plunger 29a is located at the projecting position and the second oil supply passage 23 is closed. When in the state, the return passage 3
0 communicates with the downstream portion 23b, while the return passage 30 is disconnected from the second oil supply passage 23 when the plunger 29a is in the retracted position and the second oil supply passage 23 is in the open state. Is configured. In the return passage 30, the downstream portion 2 when the passage 30 communicates with the downstream portion 23b of the second oil supply passage 23.
When the hydraulic pressure in 3b is likely to exceed the second set pressure lower than the operating pressure of the hydraulic plunger mechanism 43 described later, the downstream portion 2
A relief valve 32 for returning the oil in 3b to the oil pan 11 via the return passage 30 is installed.

As shown in FIGS. 3 and 4, a cam shaft 33, an intake side rocker shaft 25 and an exhaust side rocker shaft 21 are supported in parallel with each other in the cylinder head, and the cam shaft 33 corresponds to each cylinder. Two intake side low speed cams 33a, 33a, one intake side high speed cam 33b and one exhaust side cam 33c are provided. The intake side high speed cam 33b has a longer opening period of an intake valve 38 described later than the intake side low speed cam 33a, and
It is designed to have a large lift amount.

On the intake side rocker shaft 25, two intake side low speed rocker arms 34, 34 corresponding to each cylinder and one intake side high speed rocker arm 35 located therebetween are swingably supported. ing. At one end of each intake side low speed rocker arm 34, an intake side low speed cam 33 is provided.
A roller follower 36 that comes into contact with a is rotatably attached, while a hydraulic lash adjuster 37 that adjusts valve lash is attached to the other end of each intake side low speed rocker arm 34.
7 is in contact with the upper end of the intake valve 38. Further, a roller follower 39 that is in contact with the intake side high speed cam 33b is attached to one end of each intake side high speed rocker arm 35. Further, one exhaust side rocker arm 4 is provided on the exhaust side rocker shaft 21 for each cylinder.
0 is swingably supported and each exhaust side rocker arm 40
While the roller follower 41 attached to one end of the roller abuts the exhaust side cam 33c, the exhaust side rocker arm 40
The other end of the exhaust valve 42 is in contact with the upper end of the exhaust valve 42 via a lash adjuster (not shown).

A hydraulic plunger mechanism 43 is provided between each intake side high speed rocker arm 35 and the adjacent intake side low speed rocker arms 34. That is, the intake side high speed rocker arm 35 is formed with two cylinder portions 44, 44, while the intake side low speed rocker arm 34.
Fitting holes 45 are formed at corresponding positions of No. 4.
A plunger 46 is movably fitted into each fitting hole 45 in each cylinder portion 44, and a receiver 47 with which the plunger 46 abuts is slidably inserted into each fitting hole 45. The receiver 47 is biased toward the plunger 46 by a spring 48 that is contracted between the receiver 47 and the bottom of the fitting hole 45. A hydraulic chamber 50 is provided in each cylinder portion 44,
In each hydraulic chamber 50, a downstream portion 2 of the second oil supply passage 23 is provided via an oil passage 51 in the intake side rocker shaft 25.
Oil is supplied and discharged from 3b.

When the entire plunger 46 is housed in the cylinder portion 44, the intake-side high-speed rocker arm 35 and the adjacent intake-side low-speed rocker arms 34, 34 are separated from each other, while the hydraulic chamber 50. When a part of the plunger 46 moves into the fitting hole 45 against the urging force of the spring 48 by supplying oil to the intake side high speed rocker arm 35 and the intake side low speed rocker arms 34 on both sides. 34 is integrally connected.

In the above configuration, the oil pump 13 is the oil pan 1
The oil sucked from No. 1 is supplied to the main gallery 17 via the first oil supply passage 16. Main gallery 17
The oil inside is supplied to the crank journal portions 20a to 20d and the oil passages inside the exhaust side rocker shaft 21 via the branch passages 18a to 18e, and is used for lubrication of each portion. In this case, the oil pressure in the main gallery 17 is adjusted by the oil pressure adjusting valve 22 provided in the first oil supply passage 16.
In other words, the hydraulic pressure in the oil passages in the crank journal portions 20a to 20d and the exhaust side rocker shaft 21 is suppressed to be lower than in the conventional case within a range that does not hinder lubrication of each portion.

Further, the oil pump 13 supplies oil for lubricating and for driving the hydraulic plunger mechanism 43 to the intake side rocker shaft 25 via the second oil supply passage 23. in this case,
When the engine speed is low, for example, 3500 rpm or less, the solenoid valve 29 of the hydraulic circuit 24 causes the plunger 29a to protrude, and the upstream portion 23a of the second oil supply passage 23 as shown by the solid line in FIG. And the downstream portion 23b are blocked, and the downstream portion 23b of the second oil supply passage 23 and the return passage 30 are communicated with each other.

As a result, oil is supplied to the downstream portion 23b of the second oil supply passage 23 only via the bypass passage 31.
In this state, when the hydraulic pressure in the downstream portion 23b of the second oil supply passage 23 is likely to be higher than the second set pressure, the relief valve 32 opens to cause the operating pressure of the hydraulic plunger mechanism 43 to rise. It is held at a lower pressure than. Therefore, the plungers 46 of the hydraulic plunger mechanism 43 are wholly housed in the cylinder portion 44 by the urging force of the springs 48, whereby the intake side high speed rocker arms 35 and the adjacent intake side low speed rocker arms 34 ,. 34 and 34 are separated from each other.

As a result, at low engine speed, the intake side high speed rocker arm 35 is driven individually by the intake side high speed cam 33b, while the intake side low speed rocker arm 34 is driven by the intake side low speed cam 33a. The swing of the intake side low-speed rocker arm 34 is transmitted to the valve 38,
Eventually, the intake valve 38 is opened and closed by the intake side low speed cam 33a.

On the other hand, when the engine speed is high, for example, when the engine speed exceeds 3500 rpm, the solenoid valve 29 retracts the plunger 29a as shown by the chain double-dashed line in FIG.
The upstream portion 23a and the downstream portion 23b of the oil supply passage 23 are communicated with each other, while the downstream portion 23 of the second oil supply passage 23 is connected.
b and the return passage 30 are cut off. As a result, the oil accumulated in the accumulator 26 is supplied to the downstream portion 23b through the upstream portion 23a of the second oil supply passage 23, and the oil is prevented from leaking to the return passage 30 side. The hydraulic pressure in the portion 23b rises.
Along with this, the oil flows into the cylinder portion 44 of the hydraulic plunger mechanism 43 through the oil passage 51, so that a part of the plunger 46 moves into the fitting hole 45 and the intake side high speed rocker arm 35 and the both sides. The adjacent intake-side low-speed rocker arms 34, 34 are connected. As a result, the intake-side high-speed rocker arm 35 and the intake-side low-speed rocker arm 34, 34 are integrally driven by the intake-side high-speed cam 33b, which has a larger lift than the intake-side low-speed cam 33a. 38 is opened and closed by the intake side high speed cam 33b. As a result, at the time of high rotation, the period for opening the intake valve 38 is made longer than at the time of low rotation, and
The lift amount of the intake valve 38 is made larger than that at the time of low rotation.

In the above configuration, since the hydraulic pressure in the main gallery 17 is suppressed to the minimum necessary pressure by the hydraulic pressure adjusting valve 22, the hydraulic pressure of the oil supplied to the hydraulic plunger mechanism 43 rises correspondingly, and accordingly, the hydraulic plunger mechanism 43's hydraulic pressure increases. The operation is reliable.

FIG. 5 shows the oil pressure at the inlet of the oil passage 51 in the intake side rocker shaft 25 when the oil pressure in the main gallery 17 is set to 3.0 kg / cm ² by the oil pressure adjusting valve 22 as shown by the straight line F. However, in FIG. 5, the broken line G indicates the inlet hydraulic pressure of the oil passage 51 in the intake side rocker shaft 25 when the set pressure of the regulator 14 is set to 4 kg / cm ² .
The polygonal line H is the inlet oil pressure of the oil passage 51 when the set pressure of the regulator 14 is set to 5 kg / cm ² . As is clear from the figure, the hydraulic pressure in the main gallery 17 is 3.0 kg / cm.
^When set to ² , the inlet oil pressure of the oil passage 51 becomes slightly lower than the required oil pressure when the oil temperature is high.

Next, as shown by the straight line J in FIG. 6, the hydraulic pressure in the main gallery 17 is set to 2.5 kg / cm ² by the hydraulic pressure adjusting valve 22, and the hydraulic pressure at the inlet of the oil passage 51 in the intake side rocker shaft 25 is set. Indicates. However, in FIG. 6, the broken line K indicates the inlet oil pressure of the oil passage 51 when the set pressure of the regulator 14 is set to 4 kg / cm ² , and the broken line H indicates when the set pressure of the regulator 14 is set to 5 kg / cm ² . Oil passage 5
No. 1 inlet hydraulic pressure. As is clear from the figure, when the hydraulic pressure of the main gallery 17 is set to 3.0 kg / cm ² , the inlet hydraulic pressure of the oil passage 51 becomes slightly lower than the required hydraulic pressure at high oil temperature.

Next, as shown by the straight line J in FIG. 6, the oil pressure of the main gallery 17 is set to 2.5 kg / cm ² by the oil pressure adjusting valve 22, and the oil passage 5 in the intake side rocker shaft 25 is set.
The hydraulic pressure at the inlet of No. 1 is shown. However, in FIG. 6, broken line K
Is the inlet oil pressure of the oil passage 51 when the set pressure of the regulator 14 is set to 4 kg / cm ² , and the broken line L is the regulator 1
Oil passage 51 when the set pressure of 4 is set to 5 kg / cm ²
Is the inlet hydraulic pressure. In this case, the required oil pressure of 2.2 kg / cm ² indicated by the straight line E can be secured as the inlet oil pressure of the oil passage 51 in the intake side rocker shaft 25 even when the oil temperature is high.
Therefore, the hydraulic pressure in the main gallery 17 is preferably set to about 2.5 kg / cm ² . If the hydraulic pressure in the main gallery 17 is about 2.5 kg / cm ² , sufficient lubricity can be obtained in the crank journal portions 20a to 20d and the exhaust side rocker shaft 21. In order to reduce the pump resistance at low oil temperature, the regulator 14
It is preferable that the set pressure of 1 is as low as possible.

Further, in the above-mentioned configuration, the hydraulic circuit 24 is provided with the bypass passage 31 that bypasses the portion where the plunger 29a of the solenoid valve 29 is provided and communicates the accumulator 26 with the downstream portion 23b of the second oil supply passage 23. Therefore, the upstream portion 23a and the downstream portion 2 of the second oil supply passage 23
3b is cut off, the oil is supplied for lubricating the intake side rocker shaft 25 even when the engine is running at low speed, and the intake side low speed rocker arm 34 intakes air as the engine speed increases. When switching to the high speed rocker arm 35 on the side, the bypass passage 3
1, the hydraulic pressure in the downstream portion 23b of the second oil supply passage 23 is equal to or lower than the operating pressure of the hydraulic plunger mechanism 43, but is maintained at a somewhat high pressure level near the second set pressure, so that switching can be performed quickly. It will be possible to do.

In the above-described embodiment, the period during which the intake valve 38 is opened and the lift amount are changed depending on whether the engine is running at high speed or low speed, but the intake valve 38 is run at high speed and low speed. It is also possible to change only one of the opening period and the lift amount. Further, in the above embodiment, two types of rocker arms 34 and 35 are provided only on the intake side, but rocker arms for low speed and high speed are also provided on the exhaust side as needed, and both are selectively used. It is also possible to do so. Further, it can be applied to a mechanism for stopping the operation of the valve according to the operating state.

[Effect of device]

As described above, the oil supply device for an engine according to the present invention includes the first oil supply passage for supplying oil to the crank journal portion and the hydraulic pressure of the oil provided in the first oil supply passage for supplying to the crank journal portion. And a second oil supply passage that branches from the first oil supply passage on the upstream side of the hydraulic adjustment valve and supplies oil to the hydraulic plunger mechanism.
An accumulator for temporarily accumulating oil and a switching means for opening and closing the second oil supply passage are sequentially provided in the second oil supply passage, and oil is supplied from the accumulator to the hydraulic plunger mechanism by bypassing the switching means. When the bypass passage and the second oil supply passage are closed by the switching means, the pressure of the oil supplied to the hydraulic plunger mechanism through the bypass passage is maintained at a second set pressure or lower which is lower than the operating pressure of the hydraulic plunger mechanism. Therefore, a relief valve for opening the valve to relieve oil when the second set pressure is exceeded is provided.

As a result, the hydraulic pressure of the oil supplied to the crank journal section is suppressed by the hydraulic pressure adjusting valve, and the oil is preferentially supplied to that amount, so that the hydraulic plunger mechanism does not need to be increased without increasing the pump capacity. A sufficient hydraulic pressure can be secured even when the oil temperature is high.

Also, during a switching operation that requires increasing the oil pressure supplied to the hydraulic plunger mechanism, a pressure increase from the pressure state near the second set pressure to the operating pressure is sufficient, and this is completed in a short time. The switching operation of the plunger mechanism occurs quickly. Moreover, since the oil supply required for the above switching is supplied via the accumulator, the decrease in hydraulic pressure due to the amount of oil supplied to the hydraulic plunger mechanism during this switching operation can be suppressed to a minimum. Further, there is an effect that a quick and reliable switching operation can be generated.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention, in which FIG. 1 is an explanatory diagram showing the overall configuration, FIG. 2 is a configuration diagram of a hydraulic circuit provided in a second oil supply passage, and FIG. FIG. 3 is a partial cross-sectional view of the cylinder head portion, FIG. 4 is a partial plan view of the cylinder head portion, and FIGS. 5 and 6 show the hydraulic pressure in the main gallery and the inlet hydraulic pressure in the oil passage in the intake side rocker shaft. FIG. 7 is an overall configuration diagram of the conventional example, and FIG. 8 is a graph showing the relationship between the hydraulic pressure in the main gallery and the inlet hydraulic pressure of the oil passage in the intake side rocker shaft in the conventional example. Reference numeral 16 is a first oil supply passage, 20a to 20d are crank journal portions, 22 is a hydraulic pressure adjusting valve, 23 is a second oil supply passage, 26 is an accumulator, 29a is a plunger (switching means) of a solenoid valve 29, and 31 is a bypass passage. 32 is a relief valve, and 43 is a hydraulic plunger mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Kouji Soto 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) References JP 59-68506 (JP, A) JP 57- 173513 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. An oil supply device for an engine comprising a hydraulic plunger mechanism for changing valve operating characteristics, wherein a first oil supply passage for supplying oil to a crank journal portion and a crank provided in the first oil supply passage are provided. An oil pressure adjusting valve that suppresses the oil pressure of the oil supplied to the journal portion to a first set pressure, and a second oil that branches from the first oil supply passage on the upstream side of this oil pressure adjusting valve and supplies the oil to the hydraulic plunger mechanism. A supply passage is provided, and an accumulator for temporarily accumulating oil and a switching means for opening and closing the second oil supply passage are sequentially provided in the second oil supply passage, and a switching means is connected from the accumulator to the hydraulic plunger mechanism. When the bypass passage for supplying the oil by bypass and the second oil supply passage by the switching means are closed, In order to maintain the pressure of the oil supplied to the hydraulic plunger mechanism through the pass passage at a second preset pressure that is lower than the operating pressure of the hydraulic plunger mechanism, the valve is opened and the oil is relieved when the second preset pressure is exceeded. An oil supply device for an engine, comprising: