JPH0559244B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in an oil pump device for an engine.

(Prior art) Generally, as an oil pump device for supplying lubricating oil to an engine, for example,
As seen in No. 24245, an oil pump is installed near the front end of the crankshaft, and an external gear is directly attached to this crankshaft to drive it. However, with this structure, the crankshaft becomes longer by an amount corresponding to the width to which the oil pump is attached, which becomes an obstacle when attempting to shorten the overall length of the engine.

In addition, an oil pump is installed inside the oil pan,
A system in which this oil pump is driven by a crankshaft via a chain or the like has also been adopted, but this system has a problem in that the degree of freedom in the shape of the oil pan is reduced.

On the other hand, an engine oil pump employs a mechanism in which the pressure of oil supplied to each lubricating part is maintained constant using a regulator valve. The oil relieved by this regulator valve must be returned to the low pressure side of the oil pan, etc., and a relief passage for this must be formed separately from the oil suction passage and the supply passage, and the passage structure Also, the seal structure is complicated, which is disadvantageous against oil leakage.

(Object of the Invention) In view of the above-mentioned circumstances, the present invention aims to shorten the overall length of the engine and increase the degree of freedom in the shape of the oil pan.
It is an object of the present invention to provide an oil pump device for an engine in which the relief passage of a regulator valve is simply configured when the oil pump is mounted on the outer wall of a cylinder block of the engine.

(Structure of the Invention) The oil pump device of the present invention has an oil suction port of an oil suction passage connected to an oil pan on the outer wall of a side surface extending along the crankshaft of a cylinder block of an engine, and an oil supply passage of an oil supply passage connected to each lubricating part. At the same time, the oil pump is attached to the outer wall of the cylinder block with a mounting surface parallel to the drive shaft, and the drive shaft is disposed parallel to the crankshaft, and the oil intake port of the cylinder block and the oil supply port are opened. The oil port is connected to the suction port and the discharge port that open on the mounting surface of the oil pump, and a relief passage is provided in the pump housing to internally connect the discharge port and the suction port of the oil pump. It is characterized by being equipped with a regulator valve.

(Effects of the Invention) According to the present invention, the overall length of the engine can be shortened by attaching the oil pump to the outer wall of the side surface of the cylinder block extending along the crankshaft with a mounting surface parallel to the drive shaft. and
The degree of freedom in the shape of the oil pan can be increased, and the layout of the entire engine can be made more compact.

Furthermore, a relief passage that internally connects the discharge port and suction port of the oil pump is formed in the pump housing that rotatably supports the drive shaft.
By installing a regulator valve in this relief passage, there is no need to form a relief passage to the oil pan in the cylinder block, and the number of connection passages at the connection part between the cylinder block and the oil pump can be reduced. The configuration and sealing structure can be simplified, which is advantageous in preventing oil leakage, and the drive shaft support part in the pump housing can be effectively used as a relief passage forming part, making it possible to reduce the size of large oil pumps. This has the unique effect of allowing the oil pump to be attached to the outer wall of the side surface of the cylinder block without causing any problems.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic front view of the engine, FIG. 2 is a side view of the main parts of the engine partially shown in cross section, and FIG. 3 is a cross-sectional front view taken in a direction perpendicular to the crankshaft.
FIG. 4 is a plan view of the main part of the cylinder block, partially shown in section.

In the engine 1, a cylinder head 3 is fastened onto a cylinder block 2, an oil pan 4 is mounted on the lower part of the cylinder block 2, and a head cover 5 is mounted on the cylinder head 3, respectively. A piston 6 is fitted into the cylinder bore 2a of the cylinder block 2, and the piston 6 is connected to the crankshaft 8 by a connecting rod 7 (see FIG. 3).

One end of the crankshaft 8 is connected to the cylinder block 2.
A crank pulley 11 is integrally fixed to the crankshaft 8 and is engaged with a timing belt 10 for driving a camshaft 9 of a valve mechanism. The timing belt 10 is engaged with a cam pulley 12 fixed to the camshaft 9 and two idler pulleys 13, 13 to drive the camshaft 9, and a part of the timing belt 10 is engaged with the intermediate pulley 15 of the intermediate shaft 14. and this intermediate shaft 14 is driven at the same time.

Further, a pair of balancer shafts 17 and 18 are disposed on the left and right sides of the cylinder block 2. These left and right balancer shafts 17, 18 are equipped with eccentrically formed balance weights 17a, 18a, and are housed in balancer cases 19, 19 that are integrally formed on the outer wall 2b of the cylinder block 2 (see Fig. 3). ). The front end portions of the balancer shafts 17, 18 protrude toward the front side of the cylinder block 2, and chain sprockets 20, 21 are provided at these portions, respectively. On the other hand, the intermediate shaft 14 is attached to the inner side of the intermediate pulley 15, that is, the cylinder block 2.
An intermediate sprocket 22 is provided on the side. From the intermediate sprocket 22 of the intermediate shaft 14 to the sprockets 2 of the left and right balancer shafts 17 and 18.
A timing chain 24 is engaged with the idler sprocket 23 and the idler sprocket 23.

This timing chain 24 is the left balancer shaft 1
The outer side engages with the sprocket 20 of the right balancer shaft 18, and the inner side engages with the sprocket 21 of the right balancer shaft 18, so that the left and right balancer shafts 1
7 and 18 are configured to rotate in opposite directions. The balancer shafts 17 and 18 are driven to rotate at twice the speed of the crankshaft 8, and as shown in FIG. 3, when the piston 6 is at the top dead center or bottom dead center, the balance weight 17a and 18a are provided eccentrically below the cylinder block 2 side.

Furthermore, the crank pulley 1 of the crankshaft 8
1 is formed with a belt pulley 29 to which a transmission belt 28 that drives auxiliary devices such as an alternator 26 and a water pump 27 is engaged.

On the other hand, the crankshaft 8 of the cylinder block 2
A variable displacement oil pump 30, such as a trochoid type or a gear type, is mounted on the outer wall 2b of the side surface extending along the mounting surface parallel to the drive shaft 32 of the pump housing 31 that rotatably supports the drive shaft 32. This oil pump 30
is connected to the intermediate shaft 14 and rotationally driven by the crankshaft 8. That is, the oil pump 30 is disposed at the rear of the intermediate shaft 14, and the journal portion 14a provided at the rear of the intermediate sprocket 22 of the intermediate shaft 14 is rotatably supported by the pump housing 31 of the oil pump 30. The drive shaft 3 of the oil pump 30 is attached to the rear end of the oil pump 14a.
2 are connected to each other, and oil is pumped by the rotation of a rotor 33 provided on this drive shaft 32.

The oil path including the oil pump 30 is as follows:
An oil suction passage 36 connected to a strainer 35 in the oil pan 4 is formed in the cylinder block 2, and this oil suction passage 36 opens to an oil suction port 36a formed in the outer wall 2b of the cylinder block 2. Also,
An oil feed passage 37 connected to the valve mechanism, crankshaft 8, and other lubricating parts is also formed in the cylinder block 2, and this oil feed passage 37 is an oil feed port formed in the outer wall 2b on the same side of the cylinder block 2. 37a
It is open to Oil suction port 36 of the oil suction passage 36
A suction port 30a that opens on the mounting surface of the oil pump 30 communicates with a, and a discharge port 30b that opens on the mounting surface of the oil pump 30 via the rotor 33 communicates with the oil feed port 37a of the oil feed passage 37. There is.

The oil suction passage 36 starts from an oil suction port 36a, that is, from a position higher than the suction port 30a of the oil pump 30.
A step is formed in the middle to supply oil to the oil pump 30, so that the working chamber of the rotor 33 is filled with oil even when the engine is stopped. Further, a discharge port 30b of the oil pump 30 is formed to extend upward from the rotor 33 and communicates with a feed passage 37, and this oil feed passage 37 communicates with an oil filter 38 and then passes through the main gear rally 39. It is connected to each lubricating part.

Further, inside the pump housing 31 of the oil pump 30, from the discharge port 30b to the suction port 30a.
A relief passage 40 communicating with is formed, and a regulator valve 41 is interposed in the middle of the relief passage 40. In this regulator valve 41, a spring 41b is compressed at the back of a plunger 41a that receives discharge pressure, and when the discharge pressure exceeds a set pressure due to the biasing force of this spring 41b, the plunger 41a operates to open the relief passage 40. The pump housing 31 is provided so that a part of the discharged oil is relieved to the suction port 30a within the pump housing 31.

On the other hand, in the front part of the oil pump 30,
The alternator 26 is attached, and cooling air from a cooling fan 26a built into the alternator 26 is blown out from the air hole 26b to cool the oil passing through the oil pump 30 and the oil filter 38 to lower its temperature. (See Figure 2).

According to the above configuration, the crankshaft 8 rotates as the engine 1 operates, and its driving force is transmitted via the timing belt 10 to the intermediate shaft 14 for driving the balancer shafts 17 and 18. Due to the rotation, the rotor 33 of the oil pump 30 rotates, and the oil in the oil pan 4 of the cylinder block 2 is sucked from the suction port 30a through the strainer 35 and the oil suction passage 36, and is pressurized to the discharge port 30.
The oil is supplied to each part from b through an oil feed passage 37 in the cylinder block 2, an oil filter 38, and a main gear rally 39. The discharge pressure is kept constant by the operation of a regulator valve 41 provided integrally with the oil pump 30.

At this time, the oil pump 30 is assembled into a unit and mounted on the outer wall 2b on the side of the cylinder block 2, and is driven by the camshaft 9, balancer shaft 17,
Since it uses a power transmission mechanism for 18 drives,
The crankshaft 8 can be driven without extending the length of the crankshaft 8, and the overall length of the engine can be shortened. Furthermore, since the oil pump 30 is not disposed within the oil pan 4, the degree of freedom in the shape and layout of the oil pan 4 is increased.

In addition, a regulator valve 41 for keeping the discharge pressure of the oil pump 30 constant is integrated into the pump housing 31, and the relief passage 40 is connected to the drive shaft so as to return the relief to the suction port 30a for the rotor 33. 32 is formed inside the pump housing 31 that supports the cylinder block 2.
There is no need to form a relief passage to the oil pan 4 on the outer wall 2b of the oil pan 4, and only two passage openings, one on the suction side and the other on the discharge side, can be formed, and the oil pump 30 can be installed without increasing the size. It is.

Furthermore, in the above embodiment, the drive shaft 32 of the oil pump 30 connected to the intermediate shaft 14 is
The drive shaft 32 is supported in a cantilever manner at one location of the journal portion 14a, and is provided so that the drive shaft 32 is extended rearward and connected to the rotor 33. Therefore, the alternator 2 is mounted on the outer wall 2b of the cylinder block 2.
In addition to 6, various engine accessories are arranged on the front side of the cylinder block 2 to be driven by the crankshaft 8. is made longer and the distance from the front end of the cylinder block 2 is increased to avoid interference with the auxiliary equipment. This length is appropriately set in relation to the opening positions of the oil absorption passage 36 and the oil supply passage 37.

In the above embodiment, the oil pump 30 is driven by the intermediate shaft 14 engaged with the timing belt 10, but there is also a mechanism in which the power of the crankshaft 8 is transmitted by a power transmission member. The design can be changed as appropriate so that it can be driven using the following.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of an engine equipped with an oil pump device according to an embodiment of the present invention, Fig. 2 is a side view of main parts of the engine partially shown in section, and Fig. 3 is a direction perpendicular to the crankshaft. FIG. 4 is a plan view of the main part of the cylinder block shown partially in section. 1...Engine, 2...Cylinder block, 2
b...Outer wall, 4...Oil pan, 8...Crankshaft, 14...Intermediate shaft, 10...Timing belt, 17, 18...Balancer shaft, 24...Timing chain, 30...Oil pump, 30a …
...Suction port, 30b...Discharge port, 31...Pump housing, 32...Drive shaft, 33...Rotor, 3
5...Strainer, 36...Oil absorption passage, 37...
Oil feed passage, 36a...Oil suction port, 37a...Oil feed port, 38...Oil filter, 41...Regulator valve.

Claims (1)

[Claims] 1. The oil suction port of the oil suction passage connected to the oil pan and the oil feed port of the oil feed passage connected to each lubricating part are opened on the outer wall of the side surface extending along the crankshaft of the cylinder block of the engine, and the oil pump The oil pump is attached to the outer wall of the cylinder block with a mounting surface parallel to the drive shaft, the drive shaft is arranged parallel to the crankshaft, and the oil suction port and oil supply port of the cylinder block open to the mounting surface of the oil pump. A relief passage is provided in the pump housing, which is connected to the outlet and the outlet, respectively, and internally connects the outlet and the inlet of the oil pump.
An oil pump device for an engine, characterized in that a regulator valve is interposed in the relief passage.