JPH0663444B2 - Engine lubricator - 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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine lubricating device, and more particularly, to a device for pumping lubricating oil into an engine by a trochoid pump.

(Prior Art) Conventionally, there has been a trochoid pump that supplies lubricating oil in an oil pan into an engine with a smaller shape and a simpler structure than a gear pump of the same capacity and with a small meshing noise. In an engine lubrication system using this trochoid pump, the discharge capacity of the trochoid pump changes drastically, so the discharge pressure fluctuates, and the pulsation of the lubricating oil causes vibration noise on the members provided in the discharge side passage such as the oil filter. There is a problem of shortening the service life of the trochoid pump, and as a solution to this problem, an expansion chamber is provided in the middle of the discharge side passage for the trochoid pump, and the pulsation of lubricating oil is caused by the expansion chamber. Attenuators are known (for example, Jitsukō Sho 60-39).
(See Japanese Patent Publication No. 29).

However, in the above-mentioned conventional one, although it is possible to reduce vibration noise due to pulsation of lubricating oil in the discharge side passage with respect to the trochoid pump, it is not possible to solve the new problem described below that occurs in the suction side passage. .

The discharge port and suction port of the trochoid pump are opened and closed by the rotating motion of a single rotor, respectively, but at the time of so-called overlapping when both are open, the pulsating wave generated at the discharge port is Other pulsating waves existing in the suction side passage (pulsating waves generated when the circulating oil is sucked into the trochoid pump, pulsating waves generated when the suction port is closed, and pulsating waves generated at the discharge port and the suction side The pulsating wave that has flowed back into the passage is inverted at the open end of the suction-side passage and overlaps with any one of the pulsating waves that stay in the suction-side passage),
Resonance phenomenon occurs in a specific rotation region of the engine. A large pulsating wave generated by this resonance phenomenon is transmitted to the lubricating oil in the oil pan, and further the inner wall of the oil pan is vibrated to generate a radiated sound outside the oil pan. Further, when the pulsating wave and the resonance frequency of the oil pan match, this problem becomes more serious.

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

(Object of the Invention) The present invention has been made in view of the above-described conventional problems, and provides a lubricating device for an engine, which is capable of reducing radiation noise emitted from an oil pan and which is excellent in durability and reliability. The purpose is to do.

(Structure of the Invention) In order to achieve the above object, the present invention communicates with a trochoid pump through a communication passage having a diameter smaller than an effective passage sectional area of the suction passage, in the middle of the suction passage located on the suction side. It has an expansion chamber.

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

(Example) Hereinafter, the Example of this invention is described based on drawing. First
In the figure, an appropriate amount of lubricating oil is stored in an oil pan 2 attached to the lower portion of a cylinder block 1. A trochoid pump 3 as an oil pump is fixed to the cylinder block 1, and a timing pulley 4 fixed to a drive shaft 3a of the trochoid pump 3 is attached to a crankshaft (not shown). The timing belt 5 is wound around (not shown). That is, in the trochoid pump 3, the outer rotor 3b and the inner rotor 3c are eccentrically incorporated in the casing, and the inner rotor is rotated by the rotation of the crankshaft.
3b is driven and the outer rotor 3c is rotated in the same direction,
It is configured to perform a pumping action by causing a volume change in a gap formed by the inner and outer rotors. Also,
A suction side passage 9 composed of a connecting portion 6, a strainer pipe 7, and an oil strainer 8 is connected to the suction inlet 3d of the trochoid pump 3, while a discharge side passage A for guiding lubricating oil into the engine is connected to the discharge outlet 3e. It is connected. Further, as shown in FIGS. 2 and 3, a plurality of expansion chambers 11 are formed in the flange portion 7a of the oil strainer pipe 7 via a plurality of communication passages 10 having a diameter smaller than the effective passage sectional area of the suction side passage 9. It is provided inside. The communication passage 10 and the expansion chamber 11 are formed by mechanical molding such as drilling or casting. Of these, a plug 12 is fitted to the upper part of the expansion chamber 11 to cover the recess 11a formed by the above-mentioned forming means. That is,
The expansion chamber 11 is formed by the recess 11a and the flag 12 described above. Reference numeral 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 described. The pulsating wave generated at the discharge port 3e of the trochoid pump 3 flows back to the suction side passage 9 through the suction port 3d at the time of overlap in which both the discharge port 3e and the suction port 3d are open. The resonance device including the communication passage 10 and the expansion chamber 11 attenuates the pulsating wave generated at the discharge port, thereby suppressing resonance with other pulsating waves existing in the suction side passage 9 as much as possible. As a result, the radiation 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 in the oil pan 2 can be secured as in the conventional case, so that the shape is not significantly changed.

Note that the present invention is not limited to the above-described embodiment, and any portion of the suction side passage 9 may be provided with a resonance device including a communication passage and an expansion chamber.

[Brief description of drawings]

1, 2 and 3 show an embodiment of the present invention. FIG. 1 is an enlarged view of a partial main part of a simplified engine, and FIG. 2 is a view in FIG. II-II sectional view, third
The drawing is a sectional view taken along line III-III in FIG. 2 ... Oil pan, 3 ... Trochoid pump, 9 (6,7,8)
…… Suction side passage, 10 …… Communication passage, 11 …… Expansion chamber.

Claims (1)

[Claims] 1. A pump for pumping lubricating oil in an oil pan into an engine by means of a trochoid pump, wherein an effective passage cutoff of the suction side passage is provided in the middle of the suction side passage located on the suction side with respect to the trochoid pump. An engine lubrication device comprising an expansion chamber communicating with a communication passage having a diameter smaller than the area.