JPH063149Y2 - Mechanical supercharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of Invention] (Industrial field of application) The present invention relates to an air vent that is released from a regulating valve that operates when the supercharging pressure of an internal combustion engine by a supercharger reaches or exceeds a predetermined level. The present invention relates to a mechanical supercharger that prevents noise caused by outflow noise and discharge noise of the supercharger.

(Prior Art) Conventionally, a bypass passage is provided between a discharge side passage and a suction side passage of a supercharger via a regulating valve, and when the supercharging pressure to the supercharger reaches a predetermined value or more, the adjustment is performed. The valve is opened to allow air to directly escape from the discharge side passage to the suction side passage. In such a configuration, the discharge sound of the supercharger and the outflow sound from the adjusting valve leak to the outside from the air purifier and become noise.

In order to prevent this, for example, Japanese Patent Application Laid-Open No. 59-87227 proposes to connect the discharge side of the passage provided with the adjusting valve to a conventional silencer.

(Problems to be solved by the invention) However, the device disclosed in the above publication merely serves as a measure to prevent noise generated by simply guiding the sound generated in the supercharger and its peripheral circuits to the silencer. It does not attempt to eliminate the outflow noise or the discharge noise itself generated from the supercharger body, and does not serve as a fundamental noise countermeasure. In addition, the device requires a muffler and a long bypass passage to the device in addition to the adjusting valve, which causes a problem of high cost.

In view of the above points, the present invention directly reduces the discharge noise generated by the supercharger itself, and confines the noise generated inside the pipe in the circuit between the discharge side and the supercharger so that it does not leak outside. To provide a mechanical supercharger that

[Constitution of device]

(Means for Solving the Problems) Therefore, the present invention is directed to a supercharger body having a casing and a rotor forming an air chamber between the casing, a discharge side passage of the supercharger body, and the air chamber. A bypass passage connected to, a regulating valve that opens the bypass passage when the supercharging pressure in the discharge passage exceeds a set pressure, and a bypass passage between the regulating valve and the air chamber. The check valve is provided to prevent the flow of air from the air chamber to the bypass passage, and serves as a means for solving the problem.

(Operation) The main body of the mechanical supercharger is of a roots pump type as shown in FIG. 2, and two rotors having a cocoon-shaped cross section have a casing 1
By rotating at the same angular velocity in the opposite directions in
A volume of gas surrounded by the casing 1 and the rotor is sent from the suction side (air cleaner side) to the discharge side (surge tank side), and its operation is performed in the order shown in FIGS. 3 (a) to (c). .

By the way, in the mechanical supercharger having such a structure, the air (FIG. 3 (a)) enclosed in the casing 1 and the air chamber 2 is being sent to the discharge side of the supercharger (FIG. 3 (b)). (c)) When the discharge-side air flows back into the air chamber 2 due to the pressure difference, an abnormal noise is generated.

Since the present invention has the above-mentioned configuration, when the discharge side pressure (supercharging pressure) of the supercharger reaches a predetermined value, a part of the pressure is released from the adjusting valve and the air chamber in the casing is passed through the check valve. Send to. As a result, the air pressure contained in the air chamber rises, is balanced with the discharge side pressure, and does not cause backflow of air from the discharge side into the air chamber even during supercharging. Also, since the air escaped from the adjusting valve is sent to the supercharger body, the air outflow sound from the adjusting valve is contained and attenuated between the supercharger and the discharge side passage, and the outflow sound is prevented from leaking outside. Reduce.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a mechanical supercharger showing a typical embodiment of the present invention.

In the figure, reference numeral 1 denotes a casing of a supercharger main body. In the casing 1, a pair of rotors having a cocoon-shaped cross section rotate in opposite directions via gears by driving an internal combustion engine. Reference numeral 2 denotes an air chamber formed between the casing 1 and one of the rotors, which sends air from the suction side to the discharge side without changing its volume in the main body of the supercharger to the discharge side. Reference numeral 3 denotes an internal combustion engine. In the internal combustion engine 3, the discharge side passage of the supercharger is connected to a surge tank (not shown) as usual.

A regulating valve 4 that opens the valve when the supercharging pressure reaches a predetermined level and releases a part of the pressure is provided in the middle of the discharge side passage. Check valves 6, 6 are interposed and connected to a passage 5 communicating with an air chamber 2 formed between the casing 1 of the supercharger and each rotor.

In the above-described configuration, according to the present embodiment, the regulating valve 4 does not open until the supercharging pressure reaches the predetermined pressure, and therefore, the constant amount of air is continuously sent to the internal combustion engine side by the supercharger during that time.

Now, when the supercharging pressure exceeds a predetermined value, the adjusting valve 4 is opened, and a part of it is escaped through the passage 5 and fed into the air chamber 2 of the supercharger main body. As a result, the pressure in the air chamber 2 also increases, the pressure in the air chamber 2 and the discharge side pressure are balanced during supercharging, and there is no backflow of air from the discharge side to the air chamber as in the conventional case.

Here, when the check valve 6 is not interposed in the passage 5 communicating from the adjusting valve 4 to the air chamber 2 of the supercharger main body, the high pressure air on the discharge side of the supercharger is indicated by the arrow in FIG. As a result of flowing through the passage 5 to the intake side equal to the atmospheric pressure, not only the function of the regulating valve is lost but also the supercharging function is not exerted.

(Effect of the Invention) As described above in detail, according to the present invention, when the discharge side pressure of the mechanical supercharger exceeds a predetermined value, the adjustment valve is opened to allow a part of the pressure relief valve to escape. , The function as a relief valve on the discharge side is exerted, and the air escaped from the adjustment valve is sent to the air chamber of the main body of the turbocharger through the check valve. Backflow of air from the machine discharge side to the air chamber is avoided, and as a result, it is possible to eliminate noise generation from the supercharger itself.

Further, since the present invention has the simple structure as described above, it does not require any additional silencer or an extra pipe line leading to the silencer, which leads to low cost.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a mechanical supercharger of the present invention, and FIG.
The figure is a function explanation diagram when the check valve is removed in the same machine,
FIG. 3 is a principle diagram of noise generation of the mechanical supercharger itself. Description of main parts of the drawing 1 ... Casing 2 ... Air chamber 3 ... Internal combustion engine 4 ... Regulator valve 6 ... Check valve

Claims (1)

[Scope of utility model registration request] 1. A supercharger main body having a casing and a rotor forming an air chamber between the casing, a discharge side passage of the supercharger main body and a bypass passage connected to the air chamber, and the discharge side. A regulating valve that opens the bypass passage when the supercharging pressure in the passage exceeds a set pressure, and is arranged in the middle of the bypass passage between the regulating valve and the air chamber, from the air chamber to the bypass passage. A mechanical supercharger characterized by comprising a check valve for preventing the flow of air.