Freeze prevention device

Abstract

The present invention provides an antifreeze device that prevents water vapor from freezing by raising the temperature of the blow-by gas. [Solution] The antifreeze device comprises a PCV passage that recirculates blow-by gas, mainly composed of unburned gas leaked into the engine, to the intake port, and a hot water pipe that circulates hot water, forming a double-pipe structure that covers at least a portion of the outer circumference of the PCV passage. The cylindrical part of the PCV passage covered by the hot water pipe is formed in a bellows shape, and the hot water pipe has an inlet for introducing hot water and an outlet for discharging hot water. Both the inlet and outlet are provided on the side wall of the hot water pipe facing upwards towards the vehicle, and the opening of the inlet is provided above the bellows-shaped protrusion.

Description

Technical Field

[0001] The present invention relates to an anti-freezing device that prevents water vapor contained in blow-by gas from freezing.

Background Art

[0002] In order to prevent unburned gas from flowing out into the atmosphere, an engine is provided with a blow-by gas reduction device. This blow-by gas reduction device refluxes blow-by gas into the combustion chamber through a PCV passage that connects the intake side of the engine and the cylinder head cover, and burns it again. Blow-by gas contains water vapor. When the vehicle travels in an extremely low temperature environment, there is a problem that the water vapor is cooled in the PCV passage and freezes near the confluence with the intake manifold. A technique for warming the PCV passage with warm water is known for such a problem (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Recently, HEVs (Hybrid Electric Vehicles) in which the operation of the engine is suppressed and the calorific value is smaller than that of conventional gasoline vehicles, and hydrogen engine vehicles that contain a large amount of moisture in blow-by gas due to the nature of chemical reactions are actively being developed. Therefore, there has been a demand for an anti-freezing device that more efficiently raises the temperature of blow-by gas to prevent freezing of water vapor.

[0005] The present invention has been made to solve such problems, and provides an anti-freezing device that raises the temperature of blow-by gas to prevent freezing of water vapor.

Means for Solving the Problems

[0006] A specific embodiment of the present invention provides an antifreeze device comprising a PCV passage for recirculating blow-by gas, mainly composed of unburned gas leaked into the engine, to the intake port, and a hot water pipe for circulating hot water, which forms a double-pipe structure covering at least a portion of the outer circumference of the PCV passage. The cylindrical part of the PCV passage covered by the hot water pipe is formed in a bellows shape, and the hot water pipe has an inlet for introducing hot water and an outlet for discharging hot water. Both the inlet and outlet are provided on the side wall of the hot water pipe facing upwards on the vehicle, and the opening of the inlet is provided above the bellows-shaped protrusion. [Effects of the Invention]

[0007] The present invention provides an antifreeze device that prevents water vapor from freezing by raising the temperature of the blow-by gas. [Brief explanation of the drawing]

[0008] [Figure 1] This is a simplified overall view of the antifreeze device according to this embodiment. [Figure 2] This is a partial cross-sectional view of the main part of the antifreeze device, showing the flow direction of blow-by gas. [Figure 3] This is a cross-sectional view taken at point AA in Figure 2. [Figure 4] This is a magnified view of section B in Figure 2. [Modes for carrying out the invention]

[0009] The present invention will be described below through embodiments, but the claims are not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential for solving the problem.

[0010] Figure 1 is a simplified overall view of the antifreeze device 100 according to this embodiment. The antifreeze device 100 mainly consists of the antifreeze device 100, a PCV passage pipe 110, a hot water pipe 120, and a fixing plate 130. The PCV passage pipe 110 is a metal pipe that forms part of the PCV passage that recirculates blow-by gas, mainly composed of unburned gases that have leaked into the engine, to the intake port. One end of the PCV passage pipe 110 is connected to, for example, the crankcase via a connecting hose, and the other end is connected to, for example, the intake manifold via a connecting hose.

[0011] The hot water pipe 120 is a metal pipe for circulating hot water and is arranged to form a double-pipe structure by covering a portion of the outer circumference of the PCV passage pipe 110. Specifically, as will be described later, the PCV passage pipe 110 is arranged to be inserted inside the hot water pipe 120. Both ends of the hot water pipe 120 are sealed so as to be attached to the outer circumference of the PCV passage pipe 110. Two branch pipes are connected to the side wall of the hot water pipe 120: a hot water inlet pipe 121 for introducing hot water into the hot water pipe 120 and a hot water outlet pipe 122 for discharging hot water from the hot water pipe 120. The hot water circulating in the hot water pipe 120 is the coolant used to cool the engine, which has been heated to a high temperature by the engine's waste heat, and circulates, for example, between the engine and the water jacket of the cylinder head.

[0012] The fixing plate 130 is a fixing member for fixing the anti-freezing device 100 to another structure. The anti-freezing device 100 is attached, for example, to the side wall of an engine via the fixing plate 130.

[0013] Figure 2 is a partial cross-sectional view of the main part of the antifreeze device 100, showing the flow direction of the blow-by gas. As described above, the PCV passage pipe 110 is arranged to penetrate the inside of the hot water pipe 120, and the blow-by gas flows from one end of the PCV passage pipe 110 to the other, as indicated by the black arrows. The portion of the PCV passage pipe 110 covered by the hot water pipe 120 is configured as a bellows-shaped bellows pipe 111. Having a bellows pipe 111 in contact with the hot water increases the area for heat exchange between the cooled blow-by gas and the hot water, allowing the blow-by gas to be heated more efficiently even if the length of the hot water pipe 120 covering the PCV passage pipe 110 is short.

[0014] Furthermore, as described above, a hot water inlet pipe 121 and a hot water outlet pipe 122 are connected to the hot water pipe 120. Specifically, as shown in the figure, the hot water inlet pipe 121 is connected to the hot water pipe 120 so as to communicate with a hot water inlet 120a, which is an opening provided in the side wall of the hot water pipe 120, and the hot water outlet pipe 122 is connected to the hot water pipe 120 so as to communicate with a hot water outlet 120b, which is also an opening provided in the side wall of the hot water pipe 120. As indicated by the white arrows, hot water is introduced into the hot water pipe 120 from the hot water inlet pipe 121 through the hot water inlet 120a, and discharged from the hot water pipe 120 through the hot water outlet 120b to the hot water outlet pipe 122.

[0015] The hot water inlet 120a and the hot water outlet 120b are arranged in a line along the flow direction of the blow-by gas on the side wall of the hot water pipe 120. This arrangement allows the hot water introduced from the hot water inlet 120a to create turbulence within the hot water pipe 120, reaching every corner without any hot water accumulating inside the pipe, and then being discharged from the hot water outlet 120b. In other words, the heat transfer performance to the corrugated pipe 111 can be improved.

[0016] In addition, when the freeze prevention device 100 is fixed to an engine or the like by the fixing plate 130, the hot water inlet 120a and the hot water outlet 120b are arranged so as to face upward of the vehicle. By being arranged in this way, the air contained in the hot water is efficiently discharged from the hot water pipe 120.

[0017] FIG. 3 is a cross-sectional view taken along the line A-A of FIG. 2. As shown in the drawing, the bellows tube 111 portion of the PCV passage pipe 110 covered by the hot water pipe 120 forms a double-pipe structure together with the hot water pipe 120. Since the hot water flowing inside the hot water pipe 120 contacts the entire outer peripheral portion of the bellows tube 111, it is easy to transfer the heat of the hot water to the blow-by gas flowing inside the bellows tube 111.

[0018] FIG. 4 is a partially enlarged view of the portion B in FIG. 2. As described above, the hot water inlet 120a is arranged on the side wall of the hot water pipe 120 so as to face upward of the vehicle. In the present embodiment, further, it is provided above the bellows-shaped convex portion so that the hot water introduced from the hot water inlet 120a collides near the apex of the bellows-shaped convex portion. More preferably, the center of the hot water inlet 120a is offset slightly to the side opposite to the side of the hot water outlet 120b rather than directly above the apex of the convex portion so that more hot water that has collided near the apex of the convex portion is guided to the side opposite to the side of the hot water outlet 120b. By adopting such an arrangement, it can be expected that more hot water will reach the entire inside of the hot water pipe 120.

[0019] Although the freeze prevention device 100 according to the present embodiment has been described above, the hot water pipe 120 may be configured to cover the entire PCV passage pipe 110. Further, the bellows shape of the bellows tube 111 may be a wave shape that increases the side area compared to a straight tube.

Explanation of Reference Numerals

[0020] 100... Freeze prevention device, 110... PCV passage pipe, 111... Bellows tube, 120... Hot water pipe, 120a... Hot water inlet, 120b... Hot water outlet, 121... Hot water introduction pipe, 122... Hot water discharge pipe, 130... Fixing plate

Claims

[Claim 1] A PCV passage that recirculates blow-by gas, mainly composed of unburned gases that have leaked into the engine, back to the intake port, A hot water pipe for circulating hot water is provided, which covers at least a portion of the outer perimeter of the aforementioned PCV passage and forms a double-pipe structure. Equipped with, The cylindrical tube of the PCV passage covered by the hot water pipe is formed in a bellows shape. The hot water pipe has an inlet for introducing the hot water and an outlet for discharging the hot water. The inlet and outlet are both provided on the side wall of the hot water pipe facing upwards on the vehicle. The opening of the inlet is an anti-freezing device provided above the bellows-shaped protrusion.

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