JPH10205317A - Oil pump for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil pump for an internal combustion engine, capable of smoothly discharging lubricating oil in restarting the internal combustion engine. SOLUTION: A driving side pump gear (rotor) 4 is rotatably housed in a pump housing 1, and a suction chamber and a discharge chamber 7 are formed in the pump housing 1. A driving shaft 10 connected to the driving side pump gear 4 through bearing holes 8A, 8B formed in the pump housing 1 and for rotating and driving the driving side pump gear 4 is provided. Orifice holes 25A, 25B capable of releasing the inside of the discharge chamber 1 to the atmosphere are provided among the driving shaft 10 and the bearing holes 8A, 8B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil pump for an internal combustion engine which is preferably applied to a lubricating device for an internal combustion engine.

[0002]

2. Description of the Related Art This type of oil pump applied to a lubricating device of an internal combustion engine discharges lubricating oil to a discharge passage and guides the lubricating oil to a lubricating portion of the internal combustion engine through an oil filter provided in the discharge passage. It is like that. Generally, the oil filter is provided with a check valve so that the lubricating oil in the oil filter does not flow backward to the oil pump. A similar configuration is described in JP-A-1-280610, JP-A-63-151316, and the like.

[0003]

By the way, in the prior art, when the operation of the internal combustion engine is stopped, the lubricating oil in the discharge passage upstream of the oil filter and in the oil pump returns to the oil pan. , Replace with air. For this reason, when the internal combustion engine is restarted, the oil pump first discharges air and then discharges the lubricating oil to the discharge chamber and the discharge passage in the initial state of operation.

[0004] In this case, especially when the internal combustion engine is restarted in a state where the ambient temperature is low (at a low temperature start), the operating medium of the oil pump becomes air, thereby deteriorating the operating efficiency of the oil pump. The viscosity of the lubricating oil in the oil filter is high. For this reason, it takes time for the air in the oil pump and the discharge passage to be discharged, for the oil pump to discharge the lubricating oil, and for the lubricating oil to be supplied to the lubricating portion of the internal combustion engine.

The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to provide an oil pump for an internal combustion engine capable of rapidly discharging lubricating oil when the internal combustion engine is restarted. I do.

[0006]

SUMMARY OF THE INVENTION In view of the above, the invention according to claim 1 has a rotor rotatably housed in a pump housing and forming a suction chamber and a discharge chamber in the pump housing, and a rotor formed in the pump housing. A drive shaft that is connected to the rotor through the bearing hole and drives the rotor to rotate, and an orifice hole formed between the drive shaft and the bearing hole and capable of opening the discharge chamber to the atmosphere. Configuration.

According to a second aspect of the present invention, in the configuration of the first aspect, the orifice hole is a groove formed on the inner peripheral surface of the bearing hole.

According to a third aspect of the present invention, in the configuration of the first aspect, the orifice communicates with a discharge chamber via a sliding gap between the pump housing and a rotor. .

Here, the orifice hole is formed with a predetermined opening area.

In the oil pump having such a configuration, when the operation of the internal combustion engine is stopped, the lubricating oil in the oil pump returns to the oil pan and is replaced with air, but when the internal combustion engine is restarted, the oil pump is driven. As a result, the air in the oil pump is quickly discharged from the orifice hole.

By discharging the air from the oil pump, the oil pump can immediately start discharging the lubricating oil. As a result, the lubricating oil is promptly supplied to the lubricating portion of the internal combustion engine.

After the air in the oil pump has been discharged, the lubricating oil discharged from the orifice hole advantageously lubricates between the drive shaft and the bearing hole.

Therefore, an oil pump for an internal combustion engine that can quickly discharge lubricating oil when the internal combustion engine is restarted is obtained.

Further, since the oil pump can immediately start the discharge of the lubricating oil, when forming a lubricating device for an internal combustion engine using the oil pump, the suction passage is provided to advance the timing of starting the discharge of the lubricating oil. It is not necessary to dispose the oil pump near the oil pan in order to reduce the length as much as possible, so that the degree of freedom of the arrangement of the oil pump can be increased.

According to the second aspect of the present invention, the orifice hole can be easily formed.

According to the third aspect of the present invention, the air in the pump is easily discharged from the orifice hole through the sliding gap, but is discharged from the orifice hole through the sliding gap. Since the amount of lubricating oil is extremely small, the sliding gap is generally lubricated by a small amount of lubricating oil flowing from the discharge chamber to the suction chamber, which degrades the performance of the special oil pump. I will not let you.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a front view of an oil pump for an internal combustion engine showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG. 4 is CC of FIG.
It is a line sectional view.

In FIG. 1, reference numeral 1 denotes a pump housing. The pump housing 1 includes a housing member 2 having a recess 2a formed therein, and a cover member 3 for covering the opening of the recess 2a of the housing member 2.

In the pump housing 1, specifically in the recess 2a of the pump housing 1, a driving pump gear (rotor) 4 and a driven pump gear (rotor) 5 meshing with the driving pump gear 4 are rotatable. (See FIG. 2). The drive side pump gear 4 and the driven side pump gear 5 form a suction chamber 6 and a discharge chamber 7 in the concave portion 2a of the pump housing 1 (see FIG. 3).

A bearing hole 8 is provided in the pump housing 1.
A, 8B, 9A and 9B are formed. That is, bearing holes 8A and 9A are formed in the housing member 2,
Bearing holes 8B and 9B are formed in the cover member 3, respectively.

A drive shaft 10 is connected to the drive pump gear 4 through the bearing holes 8A and 8B. The drive shaft 10 has both ends on the bearing holes 8A and 8B. The pump 4 can be driven to rotate.

A driven shaft 11 rotatably supports the driven pump gear 5. The driven shaft 11 has a bearing hole 9A,
9B fixed or bearing.

A driven gear 12 is connected and fixed to an end 10a of a drive shaft 10 protruding from the pump housing 1. Reference numeral 13 denotes the driven gear 12 at the end 1 of the drive shaft 10.
It is a fixing nut for fixing to 0a.

Reference numeral 14 denotes a drive gear for driving the driven gear 12 to rotate. The drive gear 14 meshes with the driven gear 12, and is driven to rotate by an internal combustion engine (not shown), thereby driving the driven gear 12 to rotate. Thus, the drive shaft 10 is driven to rotate, and the oil pump is driven.

Reference numeral 15 denotes a relief valve.
Is a depression 1 formed in the cover member 3 facing the discharge chamber 7.
6, a through hole 17 having one end communicating with the depression 16 and the other end being open, and a communication hole 18 which is provided with a communication hole 18 communicating the through hole 17 with the suction chamber 6. I have.

That is, the relief valve 15 is connected to the recirculation passage 1.
9, the relief valve 15 biases the cup-shaped valve 20 by a check spring 22 supported by a plug 21 that seals the open end of the through-hole 17. In the normal state (illustrated), the communication hole 18 is closed by the body, and the excess pressure in the discharge chamber 7 is
The relief operation of the relief valve 15 is avoided. The body of the cup-shaped valve 20 has a communication hole 1.
8 and a radial through-hole 24 opening at the bottom of the circumferential groove 23 are formed.
The cylindrical interior of the cup-shaped valve 20 is always in communication with the suction chamber 6 through the communication hole 18.

Reference numerals 25A and 25B denote orifice holes formed between the drive shaft 10 and the bearing holes 8A and 8B. The orifice holes 25A and 25B are formed in the inner peripheral surfaces of the bearing holes 8A and 8B in this embodiment. It is formed by the formed linear groove (see FIG. 4).

The orifice holes 25A, 25B
Communicates with the discharge chamber 7 via sliding gaps 26A and 26B between the drive-side pump gear 4 and the pump housing 1. That is, the orifice hole 25A communicates with the discharge chamber 7 through a sliding gap 26A between the drive gear pump 4 and the cover member 3, and the orifice hole 25B communicates with the drive pump gear 4 and the housing member 3. Are communicated with the discharge chamber 7 through a sliding gap 26B between the two.

Reference numeral 27 denotes a suction passage which communicates the suction chamber 6 with an oil pan (not shown). Also, 2
Reference numeral 8 denotes a discharge passage. The discharge passage 28 guides the lubricating oil discharged into the discharge chamber 7 to a lubricating portion of the internal combustion engine (not shown). An oil filter (not shown) is provided in the middle of the discharge passage 28.

In such a configuration, when the drive gear 14 is rotated by an internal combustion engine (not shown), the driven gear 12 meshing with the drive gear 14 is driven to rotate, whereby the oil pump is driven. That is, the driving gear 1
4, the drive shaft 10 to which the driven gear 12 is connected is driven to rotate, and the drive pump gear 4 and the driven pump gear 5
Is driven to rotate.

By driving the oil pump, lubricating oil in an oil pan (not shown) is sucked into the suction chamber 6 through the suction passage 27 and discharged into the discharge chamber 7. The lubricating oil discharged into the discharge chamber 7 is supplied from a discharge passage 28 to a lubricating portion of the internal combustion engine via an oil filter (not shown), and is used for lubricating a sliding portion.

When the oil pump is discharging lubricating oil, a small amount of lubricating oil among the lubricating oil in the pump passes through the sliding gaps 26A and 26B from the discharge chamber 7 to the suction chamber 6.
, And the sliding gaps 26A and 26B can be lubricated.

Further, the excess pressure of the lubricating oil discharged into the discharge chamber 7 is avoided by the relief operation of the relief valve 15. That is, the cup-shaped valve 2 of the relief valve 15
0 moves against the spring force of the check spring 22,
By opening the communication hole 18, surplus oil escapes to the suction chamber 6 and the suction passage 27 via the recirculation passage 19, thereby avoiding pressure excess.

When the operation of the internal combustion engine (not shown) is stopped and the driving of the oil pump is stopped, the oil pump in the oil pump including the lubricating oil in the discharge passage 28 upstream of the oil filter (not shown) is provided. The lubricating oil returns to the oil pan (not shown) and is replaced with air.

When the internal combustion engine (not shown) is restarted from this state, the oil pump is driven, that is, the driving pump gear 4 and the driven pump gear 5 are driven to rotate, so that the oil pump is driven. The air inside the orifices 25A, 25A,
Quickly discharged from 5B.

By discharging the air from the oil pump, the oil pump can immediately start discharging the lubricating oil. As a result, the lubricating oil is promptly supplied to the lubricating portion of the internal combustion engine via an oil filter (not shown).

After the air in the oil pump is discharged, the lubricating oil discharged from the orifice holes 25A and 25B lubricates between the drive shaft 10 and the bearing holes 8A and 8B advantageously.

Therefore, an oil pump for an internal combustion engine that can quickly discharge lubricating oil when the internal combustion engine is restarted is obtained.

Further, since the oil pump can start discharging the lubricating oil promptly, when a lubricating device for an internal combustion engine is constructed with the oil pump, the suction passage 27 is used to advance the timing of starting the discharging of the lubricating oil. It is not necessary to dispose the oil pump near the oil pan (not shown) in order to reduce the length of the oil pump as much as possible, and the degree of freedom in the arrangement of the oil pump can be increased.

Since the orifice holes 25A, 25B are formed by grooves formed on the inner peripheral surfaces of the bearing holes 8A, 8B, the orifice holes 25A, 25B can be easily formed.

Since the orifice holes 25A and 25B communicate with the discharge chamber 7 through sliding gaps 26A and 26B between the pump housing 1 and the driving pump gear 4,
Although the air in the pump is easily discharged from the orifice holes 25A and 25B through the sliding gaps 26A and 26B, the amount of the lubricating oil discharged from the orifice holes 25A and 25B through the sliding gaps 26A and 26B. Since the sliding gaps 26A and 26B are generally lubricated by a small amount of lubricating oil flowing from the discharge chamber 7 to the suction chamber 6, the performance of the special oil pump is generally improved. It does not lower.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment, and can be changed without departing from the gist of the invention.
For example, the oil pump is not limited to a gear pump, and various pumps can be adopted.

In addition, the orifice hole may be formed into a groove on the outer peripheral surface of the drive shaft, and the groove may be formed in a suitable shape such as a spiral groove. Provide a bush between the bearing hole and the drive shaft,
It is also possible to use a groove formed between the butting surfaces of the bush.

[0045]

As described above in detail, according to the present invention, an oil pump for an internal combustion engine capable of rapidly discharging lubricating oil when the internal combustion engine is restarted is obtained.

Further, when configuring a lubricating device for an internal combustion engine with the oil pump, it is not necessary to dispose the oil pump near the oil pan, and the degree of freedom in the arrangement of the oil pump can be increased.

[Brief description of the drawings]

FIG. 1 is a front view of an oil pump for an internal combustion engine showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 pump housing 4 drive side pump gear (rotor) 6 suction chamber 7 discharge chamber 8A, 8B bearing hole 10 drive shaft 25A, 25B orifice hole 26A, 26B sliding gap

Claims (3)

[Claims] 1. A rotor rotatably housed in a pump housing, forming a suction chamber and a discharge chamber in the pump housing, and being connected to the rotor through a bearing hole formed in the pump housing. An oil pump for an internal combustion engine, comprising: a drive shaft that rotationally drives a rotor; and an orifice hole formed between the drive shaft and the bearing hole and capable of opening the discharge chamber to the atmosphere. 2. The device according to claim 1, wherein the orifice hole is a groove formed on an inner peripheral surface of the bearing hole.
An oil pump for an internal combustion engine as described in the above. 3. The oil pump according to claim 1, wherein the orifice hole communicates with a discharge chamber through a sliding gap between the pump housing and a rotor.