Blow-by gas recirculation device

Abstract

To simplify the structure of a blow-by gas recirculation device.SOLUTION: The blow-by gas recirculation device includes a blow-by gas pipe connecting an engine and an intake pipe, a valve body capable of closing a blow-by gas flow path formed inside the blow-by gas pipe by coming into contact with an inner wall of the blow-by gas pipe, a conductive spring biasing the valve body in a direction away from the inner wall, a first terminal connected to one end of the spring, a second terminal connected to the other end of the spring, and a power supply device supplying power to the first terminal and the second terminal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a blow-by gas recirculation device. [Background technology]

[0002] Conventionally, there is a blow-by gas recirculation device that has a blow-by gas pipe that connects the crankcase and the intake pipe and allows the blow-by gas to flow in order to recirculate the blow-by gas from inside the crankcase to the intake pipe. Patent Document 1 discloses a blow-by gas recirculation device that has a blow-by gas heater that raises the temperature of the blow-by gas to prevent the moisture contained in the blow-by gas from freezing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-173437 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the blow-by gas recirculation device of Patent Document 1 requires a separate blow-by gas heater to increase the temperature of the blow-by gas, which causes a problem of making the configuration of the blow-by gas recirculation device complicated.

[0005] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to simplify the configuration of a blow-by gas recirculation device. [Means for solving the problem]

[0006] In order to solve the above problems, the blow-by gas recirculation device of the present invention comprises: a blow-by gas pipe connecting the engine and the intake pipe; a valve body that is capable of closing a blow-by gas flow path formed inside the blow-by gas pipe by coming into contact with an inner wall of the blow-by gas pipe; a conductive spring that biases the valve body in a direction away from the inner wall; a first terminal connected to one end of the spring; a second terminal connected to the other end of the spring; a power supply device that supplies power to the first terminal and the second terminal; Equipped with. [Effects of the Invention]

[0007] According to the present invention, it is possible to simplify the configuration of the blow-by gas recirculation device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an engine system according to this embodiment. [Figure 2] FIG. 2 is a schematic diagram of the valve unit according to this embodiment. [Figure 3] FIG. 3 is a partially enlarged view of the valve unit shown in FIG. [Figure 4] FIG. 4 is a block diagram showing an example of the configuration of the control device according to this embodiment. [Figure 5] FIG. 5 is a block diagram showing an example of the functional configuration of the control device according to this embodiment. [Figure 6] FIG. 6 is a partially enlarged view showing the valve unit according to this embodiment in a fully closed position. [Figure 7] FIG. 7 is a partially enlarged view showing the valve unit according to this embodiment in a fully open position. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for facilitating understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0010] Fig. 1 is a schematic diagram showing the configuration of an engine system 1 according to this embodiment. The engine system 1 is mounted on, for example, a vehicle V. As shown in Fig. 1, the engine system 1 includes an engine 100, an intake unit 200, an exhaust unit 300, and a blow-by gas recirculation device 400.

[0011] The engine 100 includes a cylinder block 102, a crankcase 104, a cylinder head 106, a head cover 108, and an oil pan 110. The crankcase 104 is formed integrally with the cylinder block 102. The cylinder head 106 is connected to the top of the cylinder block 102. The head cover 108 is connected to the top of the cylinder head 106. The cylinder head 106 is disposed between the cylinder block 102 and the head cover 108. The oil pan 110 is connected to the bottom of the crankcase 104.

[0012] A plurality of cylinder bores 112 are formed in the cylinder block 102, and a piston 114 is slidably supported in each of the cylinder bores 112 by a connecting rod 116. In the engine 100, the space surrounded by the cylinder bores 112, the cylinder head 106, and the crown surface of the piston 114 forms a combustion chamber 118.

[0013] In the engine 100, a space surrounded by the crankcase 104 and the oil pan 110 is formed as a crank chamber 120. A crankshaft 122 is rotatably supported within the crank chamber 120. The piston 114 is connected to the crankshaft 122 via a connecting rod 116.

[0014] An intake port 124 and an exhaust port 126 are provided in the cylinder head 106 so as to communicate with the combustion chamber 118. The tip of an intake valve 128 is located between the intake port 124 and the combustion chamber 118, and the tip of an exhaust valve 130 is located between the exhaust port 126 and the combustion chamber 118.

[0015] In the engine 100, a space surrounded by the cylinder head 106 and the head cover 108 is formed as a cam chamber 132. An intake camshaft 134 and an exhaust camshaft 136 are rotatably supported in the cam chamber 132.

[0016] A plurality of intake valve cams 134a are fixed to the intake camshaft 134. The intake valve cams 134a are in contact with the ends of the intake valves 128, and rotate with the rotation of the intake camshaft 134, thereby moving the intake valves 128 in the axial direction. As a result, the intake valves 128 open and close the space between the intake port 124 and the combustion chamber 118.

[0017] A plurality of exhaust valve cams 136a are fixed to the exhaust camshaft 136. The exhaust valve cams 136a are in contact with the ends of the exhaust valves 130, and rotate with the rotation of the exhaust camshaft 136, thereby moving the exhaust valves 130 in the axial direction. As a result, the exhaust valves 130 open and close the passage between the exhaust port 126 and the combustion chamber 118.

[0018] In addition, an injector and a spark plug (not shown) are provided in the cylinder head 106. Fuel injected from the injector into the combustion chamber 118 mixes with air supplied to the combustion chamber 118 via an intake port 124 to form an air-fuel mixture. The spark plug is then ignited at a predetermined timing, and the air-fuel mixture formed in the combustion chamber 118 is burned. This combustion causes the piston 114 to reciprocate, and this reciprocating motion is converted into the rotational motion of the crankshaft 122 via the connecting rod 116.

[0019] The intake unit 200 includes an intake pipe 202, an air cleaner 204, a compressor C of the turbocharger TC, an intercooler 206, and a throttle valve 208. The intake pipe 202 includes an intake manifold. The intake manifold is connected to the upstream side of the intake port 124. An intake flow path 210 is formed inside the intake pipe 202. The intake flow path 210 communicates with the intake port 124.

[0020] An air cleaner 204, a compressor C of the turbocharger TC, an intercooler 206, and a throttle valve 208 are provided in this order from upstream to downstream in the intake pipe 202. The intake air purified by the air cleaner 204 is introduced into the combustion chamber 118 through an intake flow path 210 and the intake port 124. The intake pipe 202 is mainly formed by an upstream intake pipe 202a located upstream of the compressor C and a downstream intake pipe 202b located downstream of the compressor C.

[0021] The exhaust unit 300 includes an exhaust pipe 302, a turbine T of the turbocharger TC, a catalyst 304, and a muffler 306. The exhaust pipe 302 includes an exhaust manifold. The exhaust manifold is connected to the downstream side of the exhaust port 126. An exhaust flow path 308 is formed inside the exhaust pipe 302. The exhaust flow path 308 communicates with the exhaust port 126.

[0022] A turbine T of a turbocharger TC, a catalyst 304, and a muffler 306 are provided in this order from upstream to downstream in the exhaust pipe 302. The exhaust gas generated in the combustion chamber 118 after combustion is purified by the catalyst 304 as it passes through an exhaust flow path 308, and is then discharged to the outside through the muffler 306.

[0023] The turbocharger TC includes a compressor C, a turbine T, and a rotor shaft SH. The compressor C is composed of a compressor housing CH, the internal space of which also functions as part of the intake air flow path 210, and a compressor impeller CI housed in the compressor housing CH.

[0024] The compressor impeller CI is connected to the turbine impeller TI via the rotor shaft SH and rotates integrally with the turbine impeller TI. The compressor impeller CI rotates using the rotational power of the turbine impeller TI, compressing the intake air.

[0025] The turbine T is composed of a turbine housing TH, the interior space of which also functions as part of the exhaust flow path 308, and a turbine impeller TI housed within the turbine housing TH. The turbine impeller TI is rotated by the exhaust gas discharged from the combustion chamber 118.

[0026] The blow-by gas recirculation device 400 includes an oil separator 410, a first piping section 420, a second piping section 430, and a third piping section 440.

[0027] The oil separator 410 is provided in the crankcase 104 and communicates with the crank chamber 120. The oil separator 410 separates oil mixed in from the blow-by gas that flows into the crank chamber 120 through the gap between the cylinder bore 112 and the piston 114. In this embodiment, the oil separator 410 includes a first oil separator 412 and a second oil separator 414.

[0028] The first piping section 420 includes a first blow-by gas pipe 422 and a first PCV valve 424. In this embodiment, the first blow-by gas pipe 422 is a pipe made of resin. The first blow-by gas pipe 422 connects the engine 100 and the intake pipe 202. Specifically, the first blow-by gas pipe 422 communicates between the first oil separator 412 and the intake port 124 in the downstream intake pipe 202b and the throttle valve 208. More specifically, the first blow-by gas pipe 422 communicates between the first oil separator 412 and the intake manifold of the intake pipe 202.

[0029] A first blow-by gas passage 422a is formed inside the first blow-by gas pipe 422. The first blow-by gas passage 422a connects the crank chamber 120 and the intake passage 210 via the first oil separator 412. The first blow-by gas passage 422a returns the blow-by gas to the intake passage 210. The first PCV valve 424 is provided in the first oil separator 412 and connected to the first blow-by gas pipe 422 to prevent backflow of intake air from the intake passage 210 to the first oil separator 412. The first PCV valve 424 returns the blow-by gas from the crank chamber 120 to the downstream intake pipe 202b between the intake port 124 and the throttle valve 208 when the internal pressure of the crank chamber 120 is higher than the internal pressure of the downstream intake pipe 202b between the intake port 124 and the throttle valve 208.

[0030] The second piping section 430 includes a second blow-by gas pipe (blow-by gas pipe) 432, a second PCV valve 434, and a valve unit 500. In this embodiment, the second blow-by gas pipe 432 is a pipe made of resin. The second blow-by gas pipe 432 connects the engine 100 and the intake pipe 202. Specifically, the second blow-by gas pipe 432 communicates between the second oil separator 414 and a portion of the upstream intake pipe 202a between the air cleaner 204 and the compressor C.

[0031] A second blow-by gas flow path (blow-by gas flow path) 432a is formed inside the second blow-by gas piping 432. The second blow-by gas flow path 432a connects the crank chamber 120 and the intake flow path 210 via the second oil separator 414. The second blow-by gas flow path 432a returns the blow-by gas to the intake flow path 210. The second PCV valve 434 is provided in the second oil separator 414 and connected to the second blow-by gas piping 432 to prevent backflow of intake air from the intake flow path 210 to the second oil separator 414. The second PCV valve 434 returns the blow-by gas from the crank chamber 120 to the upstream intake pipe 202a when the internal pressure of the crank chamber 120 is higher than the internal pressure of the upstream intake pipe 202a.

[0032] Fig. 2 is a schematic configuration diagram of the valve unit 500 according to this embodiment. As shown in Fig. 2, a second blow-by gas passage 432a is formed inside the second blow-by gas piping 432. The valve unit 500 is configured to be able to open and close the second blow-by gas passage 432a.

[0033] In this embodiment, a partition wall 436 is formed as a part of the inner wall of the second blow-by gas pipe 432. A through-hole 438 is formed in the partition wall 436. The partition wall 436 formed around the through-hole 438 partitions the second blow-by gas passage 432a into an upstream blow-by gas passage 432a1 on the crank chamber 120 side and a downstream blow-by gas passage 432a2 on the intake pipe 202 side. The through-hole 438 connects the upstream blow-by gas passage 432a1 and the downstream blow-by gas passage 432a2.

[0034] The valve unit 500 includes a valve element 510, a shaft 520, an actuator 530, a spring 540, a first terminal 550, a second terminal 560, a power supply device 570, a control device 600, a thermometer 700, and a pressure gauge 710. The valve element 510 is disposed inside the second blow-by gas piping 432.

[0035] FIG. 3 is a partially enlarged view of the valve unit 500 shown in FIG. 2. As shown in FIG. 3, the valve body 510 has a protrusion 512 and a guide portion 514. The protrusion 512 is provided closer to the partition wall 436 than the guide portion 514. The protrusion 512 is formed, for example, in a truncated cone shape. The guide portion 514 is formed, for example, in a cylindrical shape. The central axis of the protrusion 512 is the same as the central axis of the guide portion 514. Here, "same" means both being completely the same and being deviated from being completely the same within the range of tolerances such as processing accuracy and assembly error. The protrusion 512 is continuous with the guide portion 514 in the central axis direction C. The central axis of the protrusion 512 and the guide portion 514 is the central axis of the valve body 510.

[0036] The outer diameter of the guide portion 514 is larger than the outer diameter of the protrusion portion 512. The outer peripheral surface of the guide portion 514 is a sliding surface that can slide on the inner wall surface (inner surface) 432c of the second blow-by gas piping 432, and has the function of guiding the valve body 510 in the central axis direction C.

[0037] An abutting portion 512a is formed at the end of the protrusion 512 opposite to the guide portion 514. The abutting portion 512a is configured to be able to abut against a contacted portion 436a of the partition wall 436. The contacted portion 436a is formed at the upper end of the through-hole 438 on the downstream blow-by gas passage 432a2 side. When the abutting portion 512a of the protrusion 512 abuts against the contacted portion 436a of the partition wall 436, the through-hole 438 is blocked and the second blow-by gas passage 432a is brought into a closed state. When the abutting portion 512a of the protrusion 512 moves away from the contacted portion 436a of the partition wall 436, the through-hole 438 is opened and the second blow-by gas passage 432a is brought into an open state.

[0038] 2, the shaft 520 is, for example, a cylindrical rod member. One end of the shaft 520 is disposed inside the second blow-by gas piping 432, and the other end of the shaft 520 is disposed outside the second blow-by gas piping 432. One end of the shaft 520 is connected to the valve body 510, and the other end of the shaft 520 is connected to the actuator 530. The central axis of the shaft 520 is the same as the central axis of the valve body 510.

[0039] The actuator 530 drives the shaft 520 in the central axis direction C to move the valve element 510 between the fully closed position and the fully open position. Specifically, the actuator 530 applies a force to the shaft 520 to move the valve element 510 from the fully open position toward the fully closed position. When the force applied by the actuator 530 to the shaft 520 becomes greater than the biasing force of the spring 540, the valve element 510 moves from the fully open position toward the fully closed position. Furthermore, the spring 540 applies a biasing force to the valve element 510 to move the valve element 510 from the fully closed position toward the fully open position. When the biasing force of the spring 540 becomes greater than the force applied by the actuator 530 to the shaft 520, the valve element 510 moves from the fully closed position toward the fully open position. The actuator 530 is, for example, an electric actuator having a solenoid or a motor. However, the actuator 530 is not limited thereto, and may be a hydraulic actuator or a pneumatic actuator. The driving of the shaft 520 by the actuator 530 is controlled based on a control command sent from the control device 600 .

[0040] The spring 540 is provided around the protrusion 512 (see FIG. 3) of the valve body 510, and is provided between the guide portion 514 (see FIG. 3) of the valve body 510 and the partition wall 436. The spring 540 in this embodiment is a conductive spring, and is made of, for example, a conductive metal. The spring 540 has an urging force and presses the guide portion 514 of the valve body 510 in a direction away from the partition wall 436.

[0041] 3, the first terminal 550 is made of a conductive metal and includes a first split terminal 552 and a second split terminal 554. The first split terminal 552 is disposed to be embedded in the wall of the second blow-by gas pipe 432. The first split terminal 552 includes a first extending portion 552a and a second extending portion (extending portion) 552b.

[0042] One end of the first extending portion 552a is disposed on the outer wall surface 432b of the second blow-by gas pipe 432, and the other end is disposed on the inner wall surface 432c of the second blow-by gas pipe 432. The first extending portion 552a extends linearly from one end to the other end in a thickness direction D of the wall between the outer wall surface 432b and the inner wall surface 432c of the second blow-by gas pipe 432. The thickness direction D is, for example, a direction perpendicular to the central axis direction C.

[0043] The second extension portion 552b is disposed such that one and the other ends are exposed to an inner wall surface 432c of the second blow-by gas pipe 432. The inner wall surface 432c has, for example, a circular cross section perpendicular to the central axis direction C of the valve body 510. One end of the second extension portion 552b is disposed at a different position in the central axis direction C of the valve body 510 from the other end of the second extension portion 552b. The one end of the second extension portion 552b is positioned closer to the partition wall 436 than the other end of the second extension portion 552b. The one end of the second extension portion 552b is continuous with the other end of the first extension portion 552a. The second extension portion 552b has a cross section perpendicular to the central axis direction C that is arc-shaped and follows the shape of the inner wall surface 432c, and extends from one end to the other end in the central axis direction C of the valve body 510.

[0044] The second split terminal 554 is formed in an annular shape and is disposed between the guide portion 514 of the valve body 510 and the spring 540. Specifically, the second split terminal 554 is joined to the underside of the guide portion 514 around the protrusion 512 of the valve body 510. For example, the second split terminal 554 is joined to the guide portion 514 of the valve body 510 by welding or adhesive. However, this is not limited thereto, and the second split terminal 554 may be sandwiched between the guide portion 514 of the valve body 510 and the spring 540 without being joined to the guide portion 514. The second split terminal 554 is sandwiched between the guide portion 514 of the valve body 510 and one end of the spring 540. Therefore, the second split terminal 554 is configured to be movable integrally with the valve body 510. The second split terminal 554 includes an annular portion 554a and an abutting portion 554b. The annular portion 554a is disposed around the protrusion 512 of the valve body 510, with its upper surface abutting the guide portion 514 and its lower surface abutting the spring 540. The annular portion 554a abutting one end of the spring 540 functions as an electrode portion. The abutting portion 554b is continuous with a part of the outer periphery of the annular portion 554a. The abutting portion 554b extends from the annular portion 554a toward the partition wall 436. The abutting portion 554b has an arc-shaped cross section including the central axis direction C. The outer edge of the abutting portion 554b is located radially outward of the outer edge of the annular portion 554a. The outer edge of the abutting portion 554b is located at the same radial position as the outer edge of the guide portion 514 of the valve body 510. Therefore, the outer edge of the abutting portion 554b can slide along the inner wall surface 432c. The abutting portion 554b is arranged so as to be able to abut against the second extending portion 552b of the first split terminal 552. In the present embodiment, the abutting portion 554b can slidably abut against the second extending portion 552b within the movable range of the valve body 510. The abutting portion 554b is made of, for example, an elastically deformable material, and abuts against the second extending portion 552b in an elastically deformed state. A restoring force acts on the abutting portion 554b in a direction approaching the second extending portion 552b.

[0045] The second terminal 560 is made of a conductive metal and has a first extending portion 562a, a second extending portion 562b, a third extending portion 562c, and an annular portion 562d. The first extending portion 562a, the second extending portion 562b, and the third extending portion 562c are embedded in the wall of the second blow-by gas pipe 432. The annular portion 562d is embedded in the partition wall 436.

[0046] One end of the first extending portion 562a is disposed on the outer wall surface 432b of the second blow-by gas pipe 432, and the other end is disposed between the outer wall surface 432b and the inner wall surface 432c of the second blow-by gas pipe 432. The first extending portion 562a extends linearly from one end to the other along the thickness direction D. One end of the first extending portion 562a is disposed at a different position in the central axis direction C of the valve body 510 from one end of the first extending portion 552a. One end of the first extending portion 562a is positioned closer to the partition wall 436 than one end of the first extending portion 552a.

[0047] One end and the other end of the second extending portion 562b are disposed between the outer wall surface 432b and the inner wall surface 432c of the second blow-by gas pipe 432. One end of the second extending portion 562b is disposed at a different position in the central axis direction C of the valve body 510 from the other end of the second extending portion 562b. One end of the second extending portion 562b is positioned on a side farther away from the partition wall 436 than the other end of the second extending portion 562b. One end of the second extending portion 562b is continuous with the other end of the first extending portion 562a. The second extending portion 562b extends linearly from one end to the other end along the central axis direction C.

[0048] The third extending portion 562c has one end and the other end disposed between the outer wall surface 432b and the inner wall surface 432c of the second blow-by gas pipe 432. The third extending portion 562c extends linearly from one end to the other end along the thickness direction D. One end of the third extending portion 562c is continuous with the other end of the second extending portion 562b. The other end of the third extending portion 562c is continuous with the annular portion 562d. The third extending portion 562c is disposed closer to the inner wall surface 432c than the first extending portion 562a.

[0049] The annular portion 562d is formed in an annular shape, is embedded in the surface of the partition wall 436 on which the abutted portion 436a is formed, and is arranged around the abutted portion 436a. The annular portion 562d is continuous with the other end of the third extending portion 562c. The upper surface of the annular portion 562d is arranged so as to be able to abut against the spring 540. The annular portion 562d abutting against the other end of the spring 540 functions as an electrode portion. In this way, the annular portion 554a of the first terminal 550 is connected to one end of the spring 540, and the annular portion 562d of the second terminal 560 is connected to the other end of the spring 540.

[0050] 2, power supply device 570 supplies power to first terminal 550 and second terminal 560. The power supplied from power supply device 570 is controlled based on a control command transmitted from control device 600.

[0051] FIG. 4 is a block diagram showing an example of the configuration of the control device 600 according to this embodiment. The control device 600 controls the entire valve unit 500. As shown in FIG. 4, the control device 600 includes an I / F 610, a storage device 620, a system bus 630, one or more processors 640, and one or more memories 650. The I / F 610 is an interface for communicating with the thermometer 700, the pressure gauge 710, the power supply device 570, and the actuator 530. For example, the I / F 610 acquires data transmitted from the thermometer 700 and the pressure gauge 710. The I / F 610 also transmits control signals to the actuator 530 and the power supply device 570.

[0052] The storage device 620 is composed of RAM, flash memory, HDD, etc., and holds various information necessary for the processing of the processor 640 described below. The system bus 630 electrically connects the I / F 610, storage device 620, processor 640, and memory 650, and is a transmission path for transmitting data among them.

[0053] The processor 640 includes, for example, a CPU (Central Processing Unit). The memory 650 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM is a storage element that stores programs and calculation parameters used by the CPU. The RAM is a storage element that temporarily stores data such as variables and parameters used in processing executed by the CPU.

[0054] Fig. 5 is a block diagram showing an example of the functional configuration of the control device 600 according to this embodiment. For example, as shown in Fig. 5, the control device 600 includes a valve control unit 600a and a power control unit 600b.

[0055] The processor 640 cooperates with the programs contained in the memory 650 and executes the programs contained in the memory 650 to realize various processes including the processes described below that are performed by the valve control unit 600a and the power control unit 600b.

[0056] Valve control unit 600a controls actuator 530 based on the state of engine 100, controls valve element 510 between a fully open position and a fully closed position, and controls valve element 510 to an open state or a closed state. Power control unit 600b controls the power supplied from power supply device 570 based on information output from at least one of thermometer 700 and pressure gauge 710. The details of power control unit 600b will be described later.

[0057] Returning to FIG. 2 , the thermometer 700 measures the environmental temperature. For example, the thermometer 700 is provided in the vehicle V and measures the temperature of the air in the external environment of the vehicle V. However, without being limited to this, the thermometer 700 may measure the temperature of the air in the internal environment of the vehicle V. Furthermore, the thermometer 700 may be provided in the second blow-by gas piping 432 and measure the temperature of the gas in the internal environment of the second blow-by gas piping 432. The thermometer 700 transmits information indicating the measured temperature to the control device 600.

[0058] The pressure gauge 710 is provided in the second blow-by gas pipe 432 and measures the pressure inside the second blow-by gas pipe 432. Specifically, the pressure gauge 710 measures the pressure inside the upstream blow-by gas flow passage 432a1 of the second blow-by gas pipe 432. The pressure gauge 710 transmits information indicating the measured pressure to the control device 600.

[0059] Returning to FIG. 1 , the third piping section 440 includes a third blow-by gas pipe 442. The third blow-by gas pipe 442 connects the engine 100 and the intake pipe 202. Specifically, the third blow-by gas pipe 442 communicates between the cam chamber 132 and the portion of the downstream intake pipe 202b between the intercooler 206 and the throttle valve 208. A scavenging passage 442a is formed inside the third blow-by gas pipe 442. In addition, a vent hole 444 is formed in the cylinder block 102 and the cylinder head 106 of the engine 100. The vent hole 444 communicates between the crank chamber 120 and the cam chamber 132.

[0060] When the engine 100 is in a running state and the turbocharger TC is not substantially supercharging, a negative pressure is created downstream of the throttle valve 208 in the intake passage 210. At this time, intake air is supplied to the crank chamber 120 via the scavenging passage 442a, the cam chamber 132, and the air vent 444, and blow-by gas in the crank chamber 120 is returned to the intake passage 210 via the first oil separator 412 and the first blow-by gas passage 422a.

[0061] On the other hand, when the engine is running and the turbocharger TC is supercharging, the intake passage 210 upstream of the compressor C becomes negative pressure. At this time, intake air is supplied to the crank chamber 120 via the scavenging passage 442a, the cam chamber 132, and the vent hole 444, and blow-by gas in the crank chamber 120 is returned to the intake passage 210 via the second oil separator 414 and the second blow-by gas passage 432a.

[0062] Blow-by gas contains moisture such as condensed water. The blow-by gas containing condensed water is introduced into the intake pipe 202 through, for example, the second blow-by gas pipe 432. When the vehicle V travels in a cold climate, the blow-by gas is cooled, and the condensed water contained in the blow-by gas may freeze. If the condensed water freezes near the fully closed position of the valve element 510 of the valve unit 500, the frozen condensed water will cause the valve element 510 to stick, blocking the second blow-by gas pipe 432. If the second blow-by gas pipe 432 is blocked, the internal pressure of the crankcase 104 may rise excessively.

[0063] Therefore, the valve unit 500 of this embodiment includes a conductive spring 540 that functions as a heating device to melt the frozen condensed water, a first terminal 550, a second terminal 560, and a power supply device 570. When the power supply device 570 supplies power to the first terminal 550 and the second terminal 560, the conductive spring 540 generates heat due to its electrical resistance, melting the frozen condensed water around the valve body 510. Furthermore, by having some of the components that make up the valve unit 500 function as a heating device, the configuration can be simplified compared to, for example, a case in which a blow-by gas heater is provided separately from the valve unit 500. The spring 540 is configured to be able to generate heat enough to melt the frozen condensed water and is made of a resistor having electrical resistance.

[0064] Fig. 6 is a partially enlarged view showing the valve unit 500 according to this embodiment in a fully closed position. As shown in Fig. 6, when the valve element 510 is in the fully closed position, the contact portion 512a comes into contact with the contacted portion 436a of the partition wall 436. When the contact portion 512a comes into contact with the contacted portion 436a, the through-hole 438 is closed, and communication between the upstream blow-by gas flow path 432a1 and the downstream blow-by gas flow path 432a2 is restricted.

[0065] When the valve body 510 is in the fully closed position, the blow-by gas is cooled and the condensed water contained in the blow-by gas freezes, causing the valve body 510 to adhere to the partition wall 436 due to the frozen condensed water, thereby blocking the second blow-by gas piping 432.

[0066] Power control unit 600b receives information indicating the temperature measured by thermometer 700. Then, power control unit 600b determines whether the temperature measured by thermometer 700 is equal to or lower than a first threshold value. The first threshold value is, for example, 0°C. If the temperature measured by thermometer 700 is equal to or lower than the first threshold value, power control unit 600b starts supplying power from power supply device 570 to first terminal 550 and second terminal 560. At this time, as shown in FIG. 6 , first split terminal 552 is in contact with second split terminal 554.

[0067] Electric power supplied from power supply device 570 flows between first terminal 550 and second terminal 560 via conductive spring 540. When electric power flows through conductive spring 540, spring 540 generates heat, melting frozen condensed water around spring 540. Therefore, even if condensed water freezes and valve element 510 becomes stuck during a cold start of engine system 1 when the outside air temperature is below 0°C, for example, the heat generated by spring 540 can melt the frozen condensed water, thereby releasing the stuck valve element 510. As a result, blockage of through-hole 438 caused by valve element 510 or frozen condensed water can be released, and an excessive increase in the internal pressure of crankcase 104 can be suppressed.

[0068] In the present embodiment, power control unit 600b controls the start of power supply based on the temperature measured by thermometer 700. However, the present invention is not limited to this. Power control unit 600b may also control the start of power supply based on the temperature measured by thermometer 700 and the pressure measured by pressure gauge 710. Specifically, power control unit 600b starts the supply of power from power supply device 570 to first terminal 550 and second terminal 560 when the temperature measured by thermometer 700 is equal to or lower than a first threshold and the pressure measured by pressure gauge 710 is equal to or higher than a second threshold. Here, the second threshold is set to a pressure determined by experiment or the like that indicates that a normal pressure reduction in the crankcase pressure is not being achieved, which is greater than the normal pressure. As a result, for example, when the outside air temperature is below 0°C and condensed water from blow-by gas freezes and blocks through-hole 438, causing a high pressure in upstream blow-by gas flow passage 432a1, the frozen condensed water can be melted by the heat generated by spring 540. As a result, the blockage of through-hole 438 caused by frozen condensed water can be released, and the internal pressure of crankcase 104 can be prevented from rising excessively.

[0069] Fig. 7 is a partially enlarged view showing the valve unit 500 according to this embodiment in a fully open position. As shown in Fig. 7, when the valve element 510 is in the fully open position, the contact portion 512a is separated from the contacted portion 436a of the partition wall 436 in the central axis direction C. When the contact portion 512a is separated from the contacted portion 436a, the through-hole 438 is opened, allowing communication between the upstream blow-by gas passage 432a1 and the downstream blow-by gas passage 432a2.

[0070] Electric power control unit 600b receives information indicating the pressure measured by pressure gauge 710. Then, electric power control unit 600b determines whether the pressure measured by pressure gauge 710 is equal to or greater than a second threshold. The second threshold is set to a pressure determined by experiment or the like that is greater than the normal crankcase internal pressure and that indicates that normal pressure reduction is not occurring. If the pressure measured by pressure gauge 710 is equal to or greater than the second threshold, electric power control unit 600b maintains the supply of power from electric power supply device 570 to first terminal 550 and second terminal 560. If the pressure measured by pressure gauge 710 is less than the second threshold, electric power control unit 600b stops the supply of power from electric power supply device 570 to first terminal 550 and second terminal 560. At this time, first split terminal 552 is in contact with second split terminal 554, as shown in FIG. 7 .

[0071] 6 and 7, the first split terminal 552 of this embodiment can abut against the second split terminal 554 when the valve element 510 is in the fully closed position or the fully open position. Therefore, the first terminal 550, the spring 540, and the second terminal 560 can be electrically connected when the valve element 510 is in any position between the fully closed position or the fully open position. Therefore, even if the valve element 510 is stuck in any position between the fully closed position or the fully open position, the spring 540 can generate heat to melt the frozen condensed water. As a result, the blockage of the through-hole 438 by the valve element 510 or the frozen condensed water can be released, and an excessive increase in the internal pressure of the crankcase 104 can be suppressed.

[0072] Furthermore, when the pressure measured by pressure gauge 710 is less than the second threshold value, power control unit 600b determines that the frozen condensed water has melted and the blockage of through-hole 438 has been unblocked, and stops the supply of power from power supply device 570 to first terminal 550 and second terminal 560. This makes it possible to stop heat generation by spring 540 after the frozen condensed water has melted, and to reduce unnecessary power consumption.

[0073] As described above, the blow-by gas recirculation device 400 of this embodiment includes the valve body 510, the conductive spring 540, the first terminal 550, the second terminal 560, and the power supply device 570. The valve body 510 is configured to be able to close the second blow-by gas flow path 432a formed inside the second blow-by gas piping 432 by abutting against the partition wall 436, which is the inner wall of the second blow-by gas piping 432. The conductive spring 540 biases the valve body 510 in a direction away from the partition wall 436. The first terminal 550 is connected to one end of the spring 540. The second terminal 560 is connected to the other end of the spring 540. The power supply device 570 supplies power to the first terminal 550 and the second terminal 560. As a result, when power supply device 570 supplies power to first terminal 550 and second terminal 560, conductive spring 540 can be made to generate heat, and condensed water frozen around spring 540 can be melted. As a result, blockage of through-hole 438 caused by valve element 510 or frozen condensed water can be released, and an excessive increase in internal pressure of crankcase 104 can be suppressed. Furthermore, by making some of the components constituting valve unit 500 function as a heating device, the configuration can be simplified compared to, for example, a case in which a blow-by gas heater is provided separately from valve unit 500.

[0074] In the present embodiment, the first terminal 550 includes a first split terminal 552 provided in the second blow-by gas pipe 432, and a second split terminal 554 sandwiched between the valve body 510 and one end of the spring 540 and provided so as to be movable integrally with the valve body 510. The first split terminal 552 has a second extending portion 552b exposed to an inner wall surface 432c of the second blow-by gas pipe 432 and extending along the movement direction of the central axis C of the valve body 510. The second split terminal 554 has an abutting portion 554b that slidably abuts on the second extending portion 552b within the movable range of the valve body 510. This allows electrical conduction among the first terminal 550, the spring 540, and the second terminal 560 at any position of the valve body 510 between the fully closed position and the fully open position. Therefore, even if the valve element 510 is stuck at any position between the fully closed position and the fully open position due to frozen condensed water, the spring 540 can generate heat to melt the frozen condensed water.

[0075] Furthermore, in this embodiment, the control device 600 controls the power supplied by the power supply device 570 based on the temperature measured by the thermometer 700. This makes it possible to determine whether the second blow-by gas pipe 432 is clogged or not depending on the outside air temperature, and to unblock the second blow-by gas pipe 432. Specifically, even if the valve body 510 is stuck due to frozen condensed water during a cold start of the engine system 1 when the outside air temperature is 0°C or lower, the heat generated by the spring 540 can melt the frozen condensed water, thereby releasing the stuck valve body 510. As a result, the blockage of the second blow-by gas pipe 432 can be unblocked.

[0076] In this embodiment, the control device 600 controls the power supplied by the power supply device 570 based on the temperature measured by the thermometer 700 and the pressure measured by the pressure gauge 710. Specifically, the control device 600 starts the power supply by the power supply device 570 when the measured temperature is equal to or lower than a first threshold value and the measured pressure is equal to or higher than a second threshold value. This makes it possible to more accurately determine whether the second blow-by gas pipe 432 is clogged, for example, depending on the outside air temperature and the pressure in the second blow-by gas passage 432a, and to unblock the second blow-by gas pipe 432. Specifically, when the outside air temperature is equal to or lower than 0°C and the through-hole 438 is clogged due to frozen condensed water of the blow-by gas, causing a high pressure in the upstream blow-by gas passage 432a1, the heat generated by the spring 540 can melt the frozen condensed water, thereby releasing the stuck valve body 510. As a result, the blockage of the second blow-by gas pipe 432 can be unblocked.

[0077] While the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0078] In the above embodiment, an example has been described in which first split terminal 552 has second extension portion 552b. However, this is not limiting, and first split terminal 552 may have only first extension portion 552a without second extension portion 552b. In this case, abutting portion 554b of second split terminal 554 may be able to abut against first extension portion 552a when valve body 510 is in the vicinity of the fully closed position.

[0079] In the above embodiment, an example has been described in which the valve unit 500 is provided in the second blow-by gas pipe 432. However, the location of the valve unit 500 is not limited to this, and for example, the valve unit 500 may be provided in the first blow-by gas pipe 422, or may be provided in both the first blow-by gas pipe 422 and the second blow-by gas pipe 432. In other words, the valve unit 500 is provided in at least one of the first blow-by gas pipe 422 and the second blow-by gas pipe 432.

[0080] In the above embodiment, an example has been described in which the valve unit 500 includes the control device 600, the thermometer 700, and the pressure gauge 710. However, the present invention is not limited to this, and the valve unit 500 does not necessarily have to include the control device 600, the thermometer 700, and the pressure gauge 710. For example, the power supply device 570 may always supply power to the first terminal 550 and the second terminal 560 regardless of the ambient temperature or the pressure in the second blow-by gas passage 432a. [Explanation of symbols]

[0081] 400 Blow-by gas recirculation device 500 valve unit 510 Valve body 520 shaft 530 Actuator 540 Spring 550 1st terminal 552 1st split terminal 554 2nd split terminal 560 2nd terminal 570 Power supply equipment 600 control device 700 thermometer 710 Pressure Gauge

Claims

1. a blow-by gas pipe connecting the engine and the intake pipe; a valve body that is capable of closing a blow-by gas flow path formed inside the blow-by gas pipe by coming into contact with an inner wall of the blow-by gas pipe; a conductive spring that biases the valve body in a direction away from the inner wall; a first terminal connected to one end of the spring; a second terminal connected to the other end of the spring; a power supply device that supplies power to the first terminal and the second terminal; Equipped with Blow-by gas recirculation device.

2. The first terminal is a first split terminal provided in the blow-by gas pipe; a second divided terminal that is sandwiched between the valve body and one end of the spring and is provided so as to be movable integrally with the valve body, The first divided terminal is an extension portion that is exposed to an inner surface of the blow-by gas pipe and extends along the movement direction of the valve body, The second divided terminal is a contact portion that slidably contacts the extension portion within a movable range of the valve body; The blow-by gas recirculation device according to claim 1.

3. A thermometer and a control device that controls the power supply device; Equipped with the control device controls the power supplied by the power supply device based on the temperature measured by the thermometer.

3. The blow-by gas recirculation device according to claim 1 or 2.

4. a pressure gauge for measuring the pressure inside the blow-by gas piping; Equipped with the control device controls the power supplied by the power supply device based on the temperature measured by the thermometer and the pressure measured by the pressure gauge. The blow-by gas recirculation device according to claim 3.

5. The control device When the temperature is equal to or lower than a first threshold value and the pressure is equal to or higher than a second threshold value, the power supply device starts supplying the power.

5. The blow-by gas recirculation device according to claim 4.

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