JPS62165521A - Lubrication device for engine - Google Patents

Abstract

PURPOSE:To reduce an emitting sound from the oil pan, by furnishing expansion chambers linking to the suction passage through linking passages with a bore smaller than the effective flow section area of the suction side passage, on the way of the suction passage in a trochoidal pump. CONSTITUTION:At a cylinder block 1, an oil pan 2 and a trochoidal pump 3 are furnished. At the suction port 3d of the pump 3, is furnished a suction side passage 9 consisting of a connecting member 6, a strainer pipe 7, and an oil strainer 8, while at the discharge port 3e, is furnished a discharge side passage A to lead the lubrication oil into the engine. In such a composition, at the inside of a flange 7a of the retainer pipe 7, are furnished plural expansion chambers 11 through plural linking passages 10 with a bore smaller than the effective flow section area of the suction side passage 9. Therefore, pulsation waves produced at the discharge port 3e can be decreased by a resonator consisting of the linking passages 10 and the expansion chambers 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine lubricating system, and more particularly to one in which lubricating oil is pumped into an engine using a trophite pump.

(Prior Art) Conventionally, lubricating oil in an oil pan has been supplied into an engine using a trophite pump, which is smaller in size and simpler in structure than a gear pump or the like of the same capacity, and produces less noise due to engagement. In an engine lubricating system using a trochoid pump, the discharge pressure fluctuates due to the drastic change in the discharge capacity of the trochoid pump, and the pulsation of the lubricating oil causes vibrations and noise in the parts provided with the discharge side passage Fζ, such as the oil filter. In order to solve this problem, an expansion chamber is provided in the middle of the discharge side passage of the trochoid pump, and the expansion chamber suppresses the pulsation of the lubricating oil. There are known things that cause damping (for example,
(See Publication No. 0-3926).

However, in the above-mentioned conventional pump, although it is possible to reduce the vibration noise caused by the pulsation of lubricating oil in the discharge side passage compared to the trochoid pump, it has not been possible to eliminate the new invention described below that occurs in the suction side passage. I can't.

The outlet and suction ports of the Trophit pump are opened and closed by the rotational movement of a single motor, but when both are in the open state, so-called overlap, the pulsating waves generated at the outlet are transmitted to the suction side passage. Other pulsating waves that flow back into the suction side passage (pulsating waves that occur when lubricating oil is sucked into the trochoid pump, pulsating waves that occur when the suction port is blocked, pulsating waves that occur at the discharge port) The pulsating waves that are generated and flowing back into the suction side passage are reversed at the open end of the suction side passage, overlap in the same phase with any of the pulsating waves that stay in the suction side passage, and in a specific rotation range of the engine. This causes a resonance phenomenon.

The invention is that the large pulsating waves generated by this resonance phenomenon are transmitted to the lubricating oil in the oil pan, and further move the inner wall of the oil pan to generate sound radiated from the outside of the oil pan. Further, if the pulsating wave and the resonant frequency of the oil pan match, this problem becomes even more pronounced.

In order to solve this opening/closing problem, it is possible to eliminate the overlap between the suction port and the discharge port, but in this case, when the viscosity of the lubricating oil is high, such as when the engine is cold,
At the beginning of discharge from the trochoid pump, a sufficient discharge area cannot be obtained and liquid pumping may occur, which may damage the pump, which is undesirable.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and provides an engine lubrication device that reduces the radiated sound emitted from the oil pan and has excellent durability and reliability. The purpose is to provide.

(Structure of the Invention) In order to achieve the above-mentioned object, the present invention provides a trochoid pump in the middle of the suction m1 passage located on the suction side.

An expansion chamber is provided which communicates with the suction side passage through a communication passage having a smaller diameter than the effective passage cross-sectional area of the suction side passage.

(Effects of the Invention) Since the present invention is configured as described above, even if the pulsating waves generated at the discharge port of the trochoid pump flow back into the suction side passage, the pulsating waves are transferred between the communication passage and the expansion chamber. By attenuating the resonance device, resonance with other pulsating waves existing in the suction side passage can be suppressed as much as possible, and radiation sound emitted from the oil pan can be reduced.

(Example) An example of the present invention will be described below based on the drawings. No. ＋
In Figure 1, an appropriate amount of lubricating oil is stored in an oil pan 2 installed at the bottom of a cylinder block 1. A trochoid pump 3 as an oil pump is fixed to the cylinder boot l, and a drive shaft 3 of the trochoid pump 3 is fixed to the cylinder boot l.
A timing belt 5 is wound around a timing pulley 4 fixed to a, and a timing pulley (not shown) attached to a crankshaft (not shown). Trochoid pump 3 is
The outer rotor 3b and the inner rotor 3c are assembled in an eccentric state casing, and the rotation of the crankshaft drives the inner rotor 3b and rotates the outer rotor 3c in the same direction, thereby reducing the gap formed by the inner and outer rotors. It is configured to perform a pumping action by causing a change in volume. In addition, the suction port 3d of the trochoid pump 3) is connected to the strainer pipe 7 and the oil strainer 8.
The suction side passage 9 consisting of is connected, while the discharge port 3e
is connected to a discharge side passage A that guides lubricating oil into the engine. Furthermore, the flange portion 7 of the oil strainer pipe 7
As shown in FIGS. 2 and 3, a plurality of expansion chambers 11 are provided inside the suction side passage 9 via a closed communication passage 10 having a smaller diameter than the effective passage cross-sectional area of the suction side passage 9. This communication path 1
0 and the expansion chamber 11 are formed by mechanical forming such as drilling or by casting. ``Of these, expansion room 1
1 has a recess 11a formed by the above-mentioned forming means.
A plug 12 covering the is fitted. That is, the expansion chamber 11 is formed by the above-described recess 11a and the plug 12. Note that 13 is a fixing bolt for fixing the flange portion 7a fixed to the oil strainer pipe 7 to the cylinder block 1.

Next, the operation of the above embodiment will be explained. The pulsating waves generated at the discharge port 3e of the trochoid pump 3 flow back into the suction side passage 9 through the suction port 3d during overlap when both the discharge port 3e and the suction port 3d are open. By attenuating the pulsating waves generated at the discharge port by the resonance device consisting of the passage 10 and the expansion chamber 11, resonance with other pulsating waves existing in the suction side passage 9 can be suppressed as much as possible. As a result, the radiated sound emitted from the oil pan is reduced. Further, by forming the communication passage 10 and the expansion chamber 11 in the flange portion 7a, the space within the oil pan 2 can be secured in the same way as in the conventional oil pan 2, so that a significant change in shape is not caused.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and a resonance device consisting of a communication passage and an expansion chamber may be provided at any part of the suction side passage 9.

[Brief explanation of drawings]

1, 2, and 3 show an embodiment of the present invention. FIG. 1 is an enlarged view of a simplified part of the engine, and FIG. 2 is an enlarged view of a simplified part of the engine. ■-■ Cross section, 3rd
The figure is a sectional view taken along the line ■-■ in FIG. 2・・・・・・・・・・・・Oil pan, 3...
・・・・・・・・・・・・ Trochoid pump, 9 (6
+7+8)......Suction side passage, 10......Communication passage +11...
・・・・・・・・・・・・Extension room. Patent applicant Mazda Motor Corporation Figure 1

Claims (1)

[Claims] (1) In a system in which lubricating oil in an oil pan is pumped into the engine by a trochoid pump, a part of the suction side passage located on the suction side of the trochoid pump is
A lubricating device for an engine, characterized in that an expansion chamber is provided that communicates with the suction side passage through a communication passage having a smaller diameter than the effective passage cross-sectional area of the suction side passage.