JPH04134618U - Blow-by gas reduction device - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] To ensure that blow-by gas is returned to the intake manifold under operating conditions of high rotation and high load, or at low negative pressure and high load, thereby preventing contamination of the air cleaner and carburetor. Also, clogging does not occur, and at extremely low temperatures, blow-by gas is prevented from flowing back into the air cleaner, moisture in the blow-by gas does not freeze at the inlet, and air is supplied smoothly. [Structure] An air passage 18A is provided to communicate between the air cleaner and the cylinder head cover, a return passage 24A is provided to communicate between the cover and the intake system, and a branch passage 26A is provided midway through the air passage to communicate with the intake system. A solenoid valve 28A is provided to connect and disconnect the air passage on the head cover side and the branch passage, and an engine load state detection unit 30A is provided, and a detection signal connects the air passage on the cylinder head cover side and the branch passage to prevent backflow of blow-by gas. In order to prevent this, a control section 32A is provided that controls opening and closing of the solenoid valve.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to blow-by gas reduction equipment, especially for engine cylinder blocks. The blow-by gas generated in the crank chamber of the engine is returned to the intake system through the reduction passage. The present invention relates to a blow-by gas reduction device.

0002

[Conventional technology]

Blow-by gas from the intake air in the engine's combustion chamber overflows into the crank chamber and is reduced to It flows into a separation chamber in the cylinder head cover through a passage, and in this separation chamber the oil is The air is separated, and the separated blow-by gas is sent to the intake of the engine via the reduction passage. It flows into the air system.

0003 The blow-by gas reduction device is disclosed in Japanese Utility Model Application Publication No. 55-35350. There are things to do. The blow-by gas reduction device disclosed in this publication is A return passage that returns fuel gas leaking from the engine combustion chamber into the internal space of the engine to the engine intake system. and an atmosphere introduction passageway that communicates the air cleaner and the crankcase internal space. A valve is installed in the middle of this air introduction passage, and the valve is activated when the engine starts and stops. This opens and closes the air introduction passage.

0004 Further, there is one disclosed in Japanese Utility Model Application Publication No. 56-35545. Open to this bulletin The blow-by gas recirculation device shown connects the intake passage upstream of the throttle valve and the locker room or crank. An atmospheric passage communicating between the rocker chamber or crank chamber and the intake path downstream of the throttle valve is provided. A recirculation passage is provided which communicates with the atmosphere via a control valve, and is branched from the atmospheric passage. An auxiliary passageway communicating downstream of the throttle valve via an auxiliary control valve is provided in the throttle valve.

[0005]

[Problem that the idea aims to solve]

By the way, in the conventional blow-by gas reduction device, as shown in FIG. The engine 2 is attached to the cylinder block 4, cylinder head 6, and cylinder head cover 8. The intake system of the engine 2 includes an air cleaner element 1 from the upstream side. 0, an air cleaner 12, a carburetor 14, and an intake manifold 16 are arranged in this order. ing.

[0006] Additionally, an air passage 18 that communicates between the cylinder head cover 8 and the air cleaner 12 is provided. is provided in the middle of this air passage 18 through a PCV (metering) valve 20. A return passage 24 is provided which communicates with an intake passage 22 within the manifold 16.

[0007] Then, the blow-by gas in the cylinder head cover 8 is transferred to the air passage 18 and The air is returned to the intake passage in the intake manifold 16 by the return passage 24 .

[0008] Furthermore, to explain the flow rate characteristics of the PCV valve, as shown in FIG. During high load, which is the operating condition where the negative pressure inside the air manifold is small, in other words, when the slot When the torque is fully opened, the PCV flow rate Qa, which is the suction amount of the PCV valve, increases. It is.

[0009] However, as shown in Figure 7, in the high load/high rotation range, the flow rate is higher than the PCV flow rate. Low-by gas emissions will be large.

0010 As a result, as is clear from the shaded area in Figure 7, the blow-by gas air cleaner The amount of backflow to the air tank becomes large, and the air cleaner and carburetor become contaminated. There is a risk that the vaporizer may become clogged, and the service life of the air cleaner or vaporizer will be shortened. However, it is disadvantageous in that it is disadvantageous in practice and economically.

[0011] Also, if the intake air temperature is below 0℃ or the blow-by gas inlet of the air cleaner If blow-by gas flows back into the air cleaner when the nearby temperature is extremely low, below 0℃. , the moisture in the blow-by gas freezes at the blow-by gas inlet and the air cleaner The air supply from the tank will be stopped, and the blow-by gas circulation function will deteriorate. There is the inconvenience of doing so.

0012 Furthermore, the blow-by gas reduction device is equipped with a cylinder head cover as shown in Figure 8. 8 has a two-system structure in which the air passage 18 and the reduction passage 24 are connected to each other independently. A PCV valve 20 is interposed in the middle of the return passage 24.

[0013] However, in the high load/high rotation range, blow-by gas emissions are higher than the PCV flow rate. If the blow-by gas becomes large, not only will the blow-by gas be recirculated from the reduction passage 24 to the intake system. , the air will flow backwards from the air passage 18, causing the same inconvenience as the one-system structure described above. This is what causes the combination.

[0014]

[Means to solve the problem]

Therefore, in order to eliminate the above-mentioned inconvenience, this idea was developed to A blow-by gas reduction device that recirculates the blow-by gas generated in the intake system to the intake system. In the air vent connecting the air cleaner and the engine cylinder head cover. A return passage is provided to connect the cylinder head cover and the intake system. A branch passage that connects to the intake system is provided in the middle of the air passage, and this branch part A solenoid valve is installed on the cylinder head cover side to connect and disconnect the air passage and the branch passage. A detection section is provided to detect the high load state of the engine, and the detection signal from this detection section is When entering a high load condition, the air passage on the cylinder head cover side and the branch communication The solenoid valve is connected to the air cleaner to prevent blow-by gas from flowing back into the air cleaner. It is characterized by being provided with a control section that controls opening and closing. Also, the engine cylinder blower A blow-by gas reduction device that recirculates the blow-by gas generated in the intake system to the intake system. In the air vent connecting the air cleaner and the engine cylinder head cover. A return passage is provided to connect the cylinder head cover and the intake system. A branch passage that connects to the intake system is provided in the middle of the air passage, and this branch part A switching valve is installed to disconnect the air passage on the cylinder head cover side from the branch passage. When the engine is under high load, connect the air passage and branch passage on the cylinder head cover side. The switching valve opens and closes to prevent blow-by gas from flowing back into the air cleaner. The invention is characterized in that it is provided with an actuator that causes

[0015]

[Effect]

With the above-mentioned design, the detection signal from the detection section can be input to detect high load conditions. When this occurs, the control section controls the opening and closing of the solenoid valve, and the cylinder head cover side Connect the air passage and branch passage to prevent blow-by gas from flowing back into the air cleaner. are doing.

[0016] Also, when the engine is under high load, the actuator opens and closes the switching valve. , connect the air passage on the cylinder head cover side and the branch passage to the air cleaner. Prevents backflow of blow-by gas.

[0017]

【Example】

Embodiments of this invention will be described in detail below based on the drawings.

[0018] FIG. 1 shows a first embodiment of this invention. In Figure 1, An intake manifold 16A is connected to the engine, and an air cleaner (not shown) and an air cleaner are connected to each other. An air passage 18A is provided to communicate with the cylinder head cover of the engine. A reduction passage 24A is provided to communicate between the head cover and the intake system, and the air ventilation A branch passage 26A communicating with the intake system is provided in the middle of the passage 18A.

[0019] To be more specific, in order to make the blow-by gas reduction device into a single system structure, the air passage 18A A reduction passage 24A is provided midway through the intake manifold 16A, and this reduction passage is connected to the intake manifold 16A. A PCV valve 20A is interposed in the middle of the path 24A.

[0020] In addition, it is located closer to the air cleaner than the connection part of the return passage 24A to the air passage 18A. The branch passage 26A is provided in a branched manner. At this time, the air passage 18A A first air passage 18A-1 on the upstream side and a second air passage 18A- on the downstream side of the branch part. It is divided into 2.

[0021] Then, the first air passage, which is the air passage 18A on the cylinder head cover side, is provided at the branching part. A solenoid valve 28A is provided to disconnect and disconnect the passage 18A-1 and the branch passage 26A. A detection section 30A is provided to detect a high load state of the engine, and a detection signal from this detection section 30A is provided. When the number is input and the load becomes high, the air passage 18A on the cylinder head cover side The barrel second air passage 18A-2 and the branch passage 26A are connected to supply air to the air cleaner. - A control section 32A that controls opening and closing of the solenoid valve 28A to prevent backflow of bygas. The configuration is such that

[0022] In other words, the solenoid valve 28A is connected to the control section 32A, and the throttle opening is controlled. For example, if the opening switch to detect or the vacuum switch to detect intake pipe negative pressure is opened, The detection unit 30A consisting of a power switch and the ignition coil 34A are connected. Let's go.

[0023] Then, as described in Table 1 below, the solenoid valve 28A is activated by the control section 32A. Control.

[0024] ────────────── Table 1 ────────────────

[0025] That is, when the engine speed Ne becomes equal to or higher than the set value, the detection unit 30A When the throttle opening θ of the The controller 32A operates the solenoid valve 28A to open the second air passage. 18A-2 and the branch passage 26A are controlled to communicate with each other.

[0026] Next, the effect will be explained.

[0027] The engine speed is less than the set value and the throttle from the detection unit 30A is detected. In the case of operating conditions other than the high rotation/high load range where the opening degree is also less than the set value, the above control Since there is no control signal from the section 32A, the solenoid valve 28A maintains the OFF state, and the first and second solenoid valves 28A remain OFF. The two air passages 18A-1 and 18A-2 are in communication with each other.

[0028] In addition, when the engine speed exceeds the set value, the throttle from the detection unit 30A is detected. In the case of operating conditions in the high rotation and high load range where the torque opening is greater than the set value, the control unit The control signal from 32A turns on the solenoid valve 28A, and the second air passage 18A- 2 and the branch passage 26A, and the blower that flows backward from inside the cylinder head cover. The intake gas is returned to the intake manifold 16A through the branch passage 26A.

[0029] This ensures that there is no blow-by gas that flows backwards during operating conditions in the high rotation and high load range. In fact, it can be returned to the intake manifold to eliminate blow-by gas under all operating conditions. Circulation countermeasures are well implemented and the air cleaner and carburetor are not contaminated by blow-by gas. There is no risk of damage, and the air cleaner or carburetor will not be clogged. The service life of vaporizers and vaporizers can be extended, which is advantageous both practically and economically. .

[0030] It also prevents blow-by gas from flowing back into the air cleaner even at extremely low temperatures. By preventing moisture in the blow-by gas from entering the blow-by gas inlet. There is no risk of freezing and the air can be smoothly supplied from the air cleaner. be.

[0031] FIG. 2 shows a second embodiment of the invention. In this second embodiment, the above The parts that perform the same functions as those in the first embodiment will be described with the same reference numerals.

[0032] The feature of this second embodiment is that the air cleaner 12B and the engine series An air passage 18B is provided to communicate with the cylinder head cover 8B. -8B and the intake system are provided with a return passage 24B in the middle of the air passage 18B. A branch passage 26B communicating with the intake system is provided in a branched manner, and a series is installed at this branch part. Switching to disconnect or disconnect communication between air passage 18B and branch passage 26B on the head cover side A valve 40B is provided, and air passage 1 on the cylinder head cover side is installed when the engine is under high load. 8B and the branch passage 26B to allow blow-by gas to flow back to the air cleaner 12B. An actuator 42B is provided to open and close the switching valve 40B to prevent It is in.

[0033] That is, the switching valve 40B is provided at the location where the solenoid valve in the first embodiment is provided. It is.

[0034] Also, the valve shaft 44B of the switching valve 40B is connected to the diaphragm 46 of the actuator 42B. B, and insert the switching valve 40B into the diaphragm chamber 48B of the actuator 42B. The operation shuts off the first and second air passages 18B-1 and 18B-2, and the second air passage A predetermined biasing force is set to bias 18B-2 and branch passage 26B to communicate with each other. In addition to providing a spring 50B, the diaphragm chamber 48B and the downstream side of the carburetor 14B A negative pressure passage 52B is provided which communicates with the intake manifold 16B located on the side.

[0035] Then, the operations described in Table 2 below are performed.

[0036] ────────────── Table 2 ────────────────

[0037] In other words, when the negative pressure is high and the load is low, the intake pipe negative pressure flows through the negative pressure passage 52B. acts on the diaphragm chamber 48B through the switch, resisting the biasing force of the spring 50B. Operate the valve 40B to communicate the first and second air passages 18B-1 and 18B-2. .

[0038] At this time, it was found that the amount of blow-by gas discharged did not increase compared to the PCV flow rate. (See Figure 7), the blow-by gas is transferred to the PCV valve 20B via the reduction passage 24B. The air is then refluxed into the intake manifold 16B.

[0039] In addition, when the negative pressure is low and the load is high, the actuator 42B's diamond The biasing force of the spring 50B in the flam chamber 48B is relatively larger than the negative pressure in the intake pipe. Then, the switching valve 40B shuts off the first and second air passages 18B-1 and 18B-2. As a result, the second air passage 18B-2 and the branch passage 26B are communicated with each other.

[0040] Then, the blow-by gas passes through the branch passage 26B from the second air passage 18B-2. The air then flows back into the intake manifold 16B.

[0041] This ensures that blow-by gas that flows backwards at low negative pressures and high loads is ensured. In fact, it can be returned to the intake manifold to eliminate blow-by gas under all operating conditions. The countermeasures against reflux were successfully implemented, and the blow-by gas was prevented as in the first embodiment. Therefore, there is no risk of contamination of the air cleaner or vaporizer. The service life of air cleaners and vaporizers can be extended without clogging the container. , which is practically and economically advantageous.

[0042] It also prevents blow-by gas from flowing back into the air cleaner even at extremely low temperatures. By preventing moisture in the blow-by gas from entering the blow-by gas inlet. There is no risk of freezing and the air can be smoothly supplied from the air cleaner. be.

[0043] Note that this invention is not limited to the above-mentioned first and second embodiments, and can be applied in various ways. Modifications are possible.

[0044] For example, in the first embodiment of this invention, there is a reduction passage 2 in the middle of the air passage 18A. 4A, and from the connection part between this reduction passage 24A and air passage 18A. Also, a solenoid valve 28A was installed in the middle of the air passage 18A on the air cleaner side, as shown in Figure 3. As shown, the cylinder head cover is closer to the connection part between the return passage 24C and the air passage 18C. A solenoid valve 28C is provided in the middle of the - side air passage 18C, and this solenoid valve 28C , the structure is designed to connect and disconnect the second air passages 18C-1 and 18C-2 and the branch passage 26C. It can also be done.

[0045] Then, the opening/closing operation of the solenoid valve 28C will cause the blow to the PCV valve 20C side. - It is possible to prevent the inflow of blow-by gas and prevent the back flow of blow-by gas.

[0046] In addition, in the first and second embodiments of this invention, the air passage and the reduction passage are partially Although the single system structure is shared, as shown in FIG. 4, the air passage 18D and the return passage 24 In a two-system structure where D and D are independent, a PCV valve is installed in the middle of the return passage 24D. For example, a switching valve 40D is provided in the middle of the air passage 18D, and a switching valve 40D is provided in the middle of the air passage 18D. The branch passage 26D from the exchange valve 40D is connected to the return passage downstream of the PCV valve 20D. It can also be provided by contacting 24D.

[0047] At low negative pressure and high load, the spring inside the actuator (not shown) The switching valve 40D is operated by the urging force of Gas can be reliably circulated to the intake system.

[0048]

[Effect of the idea]

As explained in detail above, according to this invention, the air cleaner and engine cylinder An air passage is provided to connect the cylinder head cover and the intake system. A return passage is provided to connect the At the same time, the air passage on the cylinder head cover side and the branch passage are connected at the branch part. A solenoid valve is installed to connect and disconnect, and a detection unit is installed to detect high engine load conditions. When the detection signal from the detection part is input and a high load condition occurs, the cylinder head cover side Connects the air passage and branch passage to prevent backflow of blow-by gas to the air cleaner. A control unit is installed to control the opening and closing of the solenoid valve, so the operating conditions in the high rotation and high load range can be controlled. Blow-by gas that flows back during There is no risk that the air cleaner or vaporizer will be contaminated by low-by gas, and the air It does not cause clogging of the cleaner or vaporizer, and is advantageous from a practical and economic point of view. Also, Prevents blow-by gas from flowing back into the air cleaner even at extremely low temperatures. As a result, the moisture in the blow-by gas freezes at the blow-by gas inlet. This allows air to be smoothly supplied from the air cleaner without any concerns.

[0049] Additionally, an air passage connects the air cleaner and the engine cylinder head cover. A return passage is provided to connect the cylinder head cover and the intake system, and an air passage is provided. A branch passage connecting to the intake system is provided along the way, and a cylinder is installed at the branch point. A switching valve is installed to connect and disconnect the air passage on the head cover side and the branch passage. Connect the air passage on the cylinder head cover side and the branch passage to prevent air leakage during high loads. Actuator that opens and closes the switching valve to prevent blow-by gas from flowing back into the liner. Blow-by gas that flows backwards at low negative pressure and high load when the negative pressure is small. can be reliably returned to the intake manifold, allowing the air to be cleaned by blow-by gas. There is no risk of contamination of the air cleaner or vaporizer, and there is no risk of the air cleaner or vaporizer becoming clogged. It is practically and economically advantageous. Furthermore, even at extremely low temperatures, the -Blow-by gas is prevented from flowing back into the air cleaner. There is no risk of moisture in the gas freezing at the blow-by gas inlet, and the air cleaner Air can be smoothly supplied from the

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a blow-by gas reduction apparatus showing a first embodiment of this invention.

FIG. 2 is a schematic diagram of a blow-by gas reduction device showing a second embodiment of the invention.

FIG. 3 is a schematic sectional view of a blow-by gas reduction device showing a first aspect of another embodiment of the invention.

FIG. 4 is a schematic diagram of a two-system structure of a blow-by gas reduction device showing a second aspect of another embodiment of the invention.

FIG. 5 is an explanatory diagram of a blow-by gas reduction device showing a conventional technique of this invention.

FIG. 6 is a diagram showing the relationship between PCV flow rate and negative pressure.

FIG. 7 is a diagram showing the relationship between blow-by gas emissions and engine rotation speed.

FIG. 8 is a schematic diagram of a two-system structure of the blow-by gas reduction device.

[Explanation of symbols]

16A intake manifold 18A Air passage 18A-1 First air passage 18A-2 Second air passage 20A PCV valve 24A Reduction passage 26A branch passage 28A solenoid valve 30A detection part 32A control section 34A ignition coil

[Table 1]

[Table 2]

Claims (2)

[Scope of utility model registration request] Claim 1: In a blowby gas return device that recirculates blowby gas generated in a cylinder block of an engine to an intake system, an air passage is provided to connect an air cleaner and a cylinder head cover of the engine, and the cylinder head cover and the intake system are connected. providing a return passageway for connecting the air passageway, and providing a branch passageway communicating with the intake system in the middle of the air passageway, and providing a solenoid valve at this branching point for disconnecting and disconnecting communication between the air passageway on the cylinder head cover side and the branch passageway;
A detection part is provided to detect the high load state of the engine, and when the detection signal from this detection part is input and the engine is in a high load state, the air passage on the cylinder head cover side and the branch passage are connected and blow-by gas is sent to the air cleaner. A blow-by gas reducing device characterized in that a control section is provided for controlling opening and closing of the electromagnetic valve to prevent backflow of the gas. [Claim 2] In a blowby gas return device that recirculates blowby gas generated in a cylinder block of an engine to an intake system, an air passage is provided to connect an air cleaner and a cylinder head cover of the engine, and the cylinder head cover and the intake system are connected. providing a return passage for connecting the air passage to the air passage; a branch passage communicating with the intake system is provided in the middle of the air passage; and a switching valve is provided at the branch portion to disconnect and disconnect communication between the air passage on the cylinder head cover side and the branch passage;
A blow-by gas return device characterized by being provided with an actuator that opens and closes the switching valve to connect the air passage on the cylinder head cover side and the branch passage to prevent blow-by gas from flowing back into the air cleaner when the engine is under high load.