valve device

Abstract

A valve device that increases or decreases a flow rate of EGR gas, the valve device comprising: a housing (12) containing: a first upstream passage (121) into which the EGR gas cooled by an EGR cooler (80) flows, a second upstream passage (122) into which the EGR gas flows, bypassing the EGR cooler, a connection point (124) connected to both a downstream side of the gas flow of the first upstream passage and a downstream side of the gas flow of the second upstream passage, and a downstream passage (123) connected to the first upstream passage and the second upstream passage via the connection point; a bypass valve body (20) provided in the second upstream passage and opening and closing the second upstream passage; an EGR valve body (14) provided in the downstream passage and rotating about an EGR valve axis (CLa) to open and close the downstream passage; a motor (24) which drives the EGR valve body in rotation; and an actuating section (28) which links the bypass valve body with a rotary operation of the EGR valve body, wherein the motor and the bypass valve body are arranged such that they are opposite each other, the connection point being inserted between the motor and the bypass valve body, the bypass valve body rotates about a bypass valve axis (CLb) to open and close the second upstream passage, the actuating section includes a cam (29) which rotates with the EGR valve body and has a cam track (291), and an output rotary section (30) which rotates with the bypass valve body and has a cam follower (302), and the output rotary portion rotates in an intermeshing manner upon rotational operation of the cam while causing the cam follower to follow the cam track, wherein the cam includes a cam through hole (29a) penetrating in an axial direction (Da) of the EGR valve axis, and the cam includes a cam projection (292) protruding from a peripheral edge (29b) of the cam through hole in the axial direction of the EGR valve axis and extending along the peripheral edge of the cam through hole.

Description

Cross-reference to similar application

[0001] This application is based on Japanese Patent Application No. 2021-128440, filed on August 4, 2021, the disclosure of which is incorporated herein by reference. Technical area

[0002] The present disclosure relates to a valve device that increases or decreases the flow rate of EGR gas. background

[0003] JP 2015-59560 A describes an EGR device. The EGR device of JP 2015-59560 A includes an EGR passage, an EGR cooler provided in the EGR passage, and an EGR bypass passage that bypasses the EGR cooler. The EGR device also includes a switching valve provided in the EGR bypass passage and opening and closing the EGR bypass passage, and an EGR valve provided in the EGR passage on the downstream side of the EGR cooler and further on the downstream side of a junction that connects the EGR bypass passage.

[0004] Since the switching valve and the EGR valve are controlled by a control device, the switching valve and the EGR valve each contain an actuator. The actuator of the switching valve is thus located close to the EGR bypass passage, for example.

[0005] Further relevant prior art is disclosed in US 2016 / 0 138 533 A1 and DE 10 2011 007 303 A1.

[0006] US 2016 / 0 138 533 A1 discloses a valve, in particular an engine control valve, equipped with a metering slide and a diverting slide. The valve has at least three channels (2, 9, 11), a metering slide (12) pivotable in a first channel (2), a diverting slide (10) capable of blocking a second (9) or third (11) channel, and an actuating device (15) for actuating the slides (10, 12). The actuating device (15) comprises an actuating wheel (16) for pivoting at least one of the slides (10, 12) and has at least a first configuration in which the metering slide (12) is in a reference position in which the diverting slide (10) does not close the second (9) or third (11) channel.The actuating device (15) is designed such that the rotation of the actuating wheel (16) in the first configuration causes a substantial pivoting of the deflection flap and a slight pivoting of the metering flap and subsequently a pivoting of the metering flap without pivoting the deflection flap.

[0007] DE 10 2011 007 303 A1 discloses a low-pressure circuit exhaust gas recirculation system having a cam groove of a linkage mechanism provided with a valve position holding cam groove, an intake throttle cam groove, and a lock-releasing cam groove for reversely rotating a low-pressure circuit EGR adjusting valve 4 from a fully closed position θ0 so that the intake throttle valve 5 is rotated. Thus, when the low-pressure circuit EGR adjusting valve is near a fully closed position θ0, a lock of the intake throttle valve can be released. That is, when the lock is released, an increase in the opening degree of the low-pressure circuit EGR adjusting valve is limited, so that influences on EGR control can be limited. Summary

[0008] In the EGR device of JP 2015-59560 A, the EGR gas flowing through an EGR bypass passage bypasses an EGR cooler and thus has a high temperature. An actuator of a switching valve provided in the EGR bypass passage is easily affected by heat from the high-temperature EGR gas flowing through the EGR bypass passage. Therefore, the actuator of the switching valve may be thermally damaged, and a failure of the switching valve may occur. The above was determined as a result of detailed studies by the inventors.

[0009] In view of the foregoing difficulties, it is an object of the present disclosure to provide a valve device capable of reducing thermal damage due to high-temperature EGR gas that has bypassed an EGR cooler.

[0010] This object is achieved by a valve device that increases or decreases a flow rate of EGR gas according to claims 1 or 2. Further advantageous embodiments are the subject of the subsequent claims.

[0011] According to one aspect of the present disclosure, a valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, an EGR valve body, a motor, and an actuator portion. The housing includes a first upstream passage into which EGR gas cooled by an EGR cooler flows, a second upstream passage into which EGR gas bypassing the EGR cooler flows, a junction connected to both a downstream side of the gas flow of the first upstream passage and a downstream side of the gas flow of the second upstream passage, and a downstream passage connected to the first upstream passage and the second upstream passage via the junction.The bypass valve body is provided in the second upstream passage and opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage and rotates about an EGR valve axis to open and close the downstream passage. The motor drives the EGR valve body to rotate. The actuator section links the bypass valve body to rotate the EGR valve body. The motor and the bypass valve body are arranged to oppose each other, with the junction between the motor and the bypass valve body being interposed.

[0012] In the valve device, the motor that drives the bypass valve body is arranged away from the second upstream passage. Thus, compared with a case where the engine is arranged adjacent to the second upstream passage, for example, the engine is less likely to be affected by the heat of the high-temperature EGR gas flowing through the second upstream passage. Thus, thermal damage due to the high-temperature EGR gas bypassing the EGR cooler can be reduced. In addition, both the EGR valve body and the bypass valve body can be driven by the engine, and thus it is possible to prevent an increase in the size of the valve device and reduce the cost of the valve device. Short description of the drawings

[0013] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings. Fig. 1 is a diagram schematically illustrating a schematic configuration of an internal combustion engine system including a valve device in a first embodiment; Fig. 2 is a diagram illustrating the valve device of the first embodiment and a partial cross-sectional view of a housing of the valve device, the section being taken along a line perpendicular to an EGR valve axis; Fig. 3 is a diagram of the valve device of the first embodiment as viewed from a side of a first upstream passage, and a partial cross-sectional view of the housing of the valve device, the section being taken along a line III-III in Fig. 2 is carried out; Fig. 4 is a partial cross-sectional view showing an adjusting section and a part of the housing of Fig. 2 are omitted; Fig. 5 a diagram showing an EGR cooler, a bypass passage and the valve device starting from Fig. 1, and which illustrates the valve device in a schematic cross-section; Fig. 6 is a cross-sectional view of a housing in a valve device, the section being taken along a line perpendicular to an EGR valve axis, in a second embodiment, Fig. 2 corresponds; Fig. 7 is a cross-sectional view of a housing in a valve device, the section being taken along a line perpendicular to the EGR valve axis, in a third embodiment, Fig. 2 corresponds; Fig. 8 is a perspective view illustrating an adjusting portion and its periphery in a detachable manner in a fourth embodiment; Fig. 9 is a perspective view illustrating an adjusting section and its periphery in a detachable manner in a fifth embodiment, and Fig. 8 corresponds; Fig. 10 is a cross-sectional view of a valve device schematically illustrating a cross section of Fig. 4 corresponds, in a sixth embodiment, and is a diagram illustrating a state in which an EGR valve body rotates to one side in a circumferential direction of the EGR valve from a fully open state of a downstream passage; Fig. 11 is a cross-sectional view schematically illustrating a cross section of Fig. 10, in a first comparative example; Fig. 12 is a diagram illustrating an EGR cooler, a bypass passage and a valve device in a detachable manner, illustrating the valve device in a schematic cross section, in a seventh embodiment, and Fig. 5 corresponds; Fig. 13 is a cross-sectional view of a valve device schematically illustrating a state in which an EGR valve body rotates to one side in the circumferential direction of the EGR valve from a fully open state of a downstream passage in an eighth embodiment, and Fig. 10 corresponds; Fig. 14 is a cross-sectional view schematically illustrating a cross section of Fig. 13, in a second comparative example; Fig. 15 is a diagram schematically illustrating an EGR cooler, a bypass passage, and a valve device in a detachable manner to describe other embodiments, and Fig. 5 corresponds; Detailed description

[0014] Each embodiment will be described below with reference to the drawings. In each of the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings. First embodiment

[0015] As in Fig. As illustrated in Figure 1, a valve device 10 in the present embodiment forms part of an internal combustion engine system 70 provided for driving the vehicle. The internal combustion engine system 70 generates driving power for traveling by igniting hydrogen as fuel and combusting the hydrogen. The internal combustion engine system 70 includes the valve device 10 and further includes an engine 71, an intake passage 72, an exhaust passage 73, an EGR passage 74, a bypass passage 75, a turbocharger 76, an intercooler 77, a throttle valve 78, an intake manifold 79, an EGR cooler 80, and a control device 85.

[0016] The engine 71 is a power source for driving the vehicle. The engine 71 includes an injector 711 and a spark plug 712 for combusting hydrogen, which is a fuel. The intake passage 72 is connected to the intake side of the engine 71 via the intake manifold 79, and the exhaust passage 73 is connected to the exhaust side of the engine 71.

[0017] In the internal combustion engine system 70, fresh air, which is external air, is sucked in from the upstream end of the intake passage 72, as indicated by an arrow Ai, and the fresh air is taken into a combustion chamber of the engine 71 via the intake manifold 79 from the intake passage 72. The fuel (more precisely, hydrogen) stored in a fuel tank 82 is decompressed by a decompression valve 83 and then supplied to the injector 711 of the engine 71.

[0018] The engine 71 ignites and combusts an air-fuel mixture obtained by mixing the fuel injected from the injector 711 and the intake air taken from the intake passage 72 through the spark plug 712 into the combustion chamber, thereby generating the driving force for driving. The exhaust gas, after combustion, passes through the exhaust passage 73 and is discharged from the downstream end of the exhaust passage 73 to the outside of the vehicle, as indicated by an arrow Ao. Fig. 1, gas flows in passages 72, 73, 74 and 75 are indicated by bold arrows.

[0019] In the intake passage 72, a compressor 761 of the turbocharger 76, the intercooler 77, and the throttle valve 78 are arranged in an upstream order. A turbine 762 of the turbocharger 76 is arranged in the exhaust passage 73.

[0020] In the turbocharger 76, an impeller of the compressor 761 and an impeller of the turbine 762 are directly connected to each other, and these impellers rotate integrally. As a result, the turbocharger 76 utilizes an exhaust flow in the exhaust passage 73 to promote the intake of air from the outside to the intake passage 72.

[0021] The intercooler 77 cools the air passing through the intercooler 77. The throttle valve 78 increases or decreases the opening degree of the intake passage 72, thereby increasing or decreasing the flow rate of the air flowing through the intake passage 72.

[0022] The EGR passage 74 is a gas passage for allowing a portion of the exhaust gas discharged from the engine 71 to flow as EGR gas to the intake side of the engine 71. The upstream end of the EGR passage 74 is connected to a downstream side of the gas flow of the engine 71 and an upstream side of the gas flow of the turbine 762 in the exhaust passage 73. The downstream end of the EGR passage 74 is connected to a downstream side of the gas flow of the throttle valve 78 and an upstream side of the gas flow of the intake manifold 79 in the intake passage 72. As a result, the EGR gas flows from the EGR passage 74 into the intake passage 72 and is sucked into the engine 71 through the intake manifold 79 together with the fresh air flowing through the intake passage 72.

[0023] The EGR cooler 80 is disposed in the EGR passage 74. The EGR cooler 80 is, for example, a heat exchanger and cools the EGR gas flowing through the EGR passage 74 by heat exchange between a cooling fluid and the EGR gas.

[0024] The bypass passage 75 is a gas passage for allowing the EGR gas to flow while bypassing or being bypassed by the EGR cooler 80. Thus, the upstream end of the bypass passage 75 is connected to an upstream side of the gas flow of the EGR cooler 80 in the EGR passage 74. The downstream end of the bypass passage 75 is connected to a downstream side of the gas flow of the EGR cooler 80 in the EGR passage 74.

[0025] In the present embodiment, the temperature of the EGR gas is controlled to be equal to or greater than the dew point on the downstream side of the gas flow of a connecting portion of the EGR passage 74 to which the downstream end of the bypass passage 75 is connected, so that the bypass passage 75 allows the EGR gas to flow while bypassing the EGR cooler 80. As a result, generation of condensed water on the downstream side of the gas flow of the connecting portion is suppressed. Specifically, for example, EGR gas containing approximately 2.4 times as much water vapor as a current diesel engine flows into the EGR passage 74 from the exhaust passage 73 because the engine 71 of the present embodiment is a hydrogen engine. Therefore, it is important to suppress generation of condensed water.

[0026] The control device 85 includes a microcomputer including a CPU, a ROM, a RAM, and the like (not shown in detail), and executes a computer program stored in a semiconductor memory such as a ROM or a RAM, which is a non-transitory tangible recording medium. The control device 85 functions as an engine control device that executes various controls related to the engine 71 and performs operation control of, for example, the engine 71, the throttle valve 78, the valve device 10, and the like.

[0027] The valve device 10 increases or decreases the flow rate of the EGR gas flowing through the bypass passage 75, and also increases or decreases the flow rate (i.e., the EGR flow rate) of the EGR gas flowing from the EGR passage 74 to the intake passage 72. Thus, the valve device 10 is provided at a passage connecting portion where the EGR passage 74 and the bypass passage 75 are connected on the downstream side of the gas flow of the EGR cooler 80.

[0028] As in the Fig. 2 and Fig. 3, the valve device 10 includes a housing 12, an EGR valve body 14, an EGR valve shaft 15, an EGR valve biasing portion 16, a bypass valve body 20, a bypass valve shaft 21, a bypass valve biasing portion 22, a motor 24, a speed reduction device 26, and an actuating portion 28. In Fig. 2, the housing 12 is illustrated in a cross-section taken along a line II-II in Fig. 3 is carried out.

[0029] As in the Fig. As illustrated in Figures 1 to 3, the housing 12 forms an outer shell of the valve device 10 and is a non-rotating member that does not rotate. A first upstream passage 121, a second upstream passage 122, a downstream passage 123, and a junction 124 through which EGR gas flows are formed within the housing 12. That is, the housing 12 is a passage forming portion, with the plurality of passages 121, 122, and 123 formed therein.

[0030] The first upstream passage 121, the junction 124, and the downstream passage 123 are connected in series from the upstream side of the gas flow in the order of the first upstream passage 121, the junction 124, and the downstream passage 123 along a direction D1 of the first passage, forming a linearly extending passage. That is, the direction of the first upstream passage 121 and the direction of the downstream passage 123 are the same, and both are the direction D1 of the first passage. The first upstream passage 121 is connected in series to the downstream passage 123 via the junction 124.

[0031] The first upstream passage 121, the junction 124, and the downstream passage 123 form a part of the EGR passage 74 on the downstream side of the gas flow of the EGR cooler 80. Thus, the EGR gas cooled by the EGR cooler 80 flows into the first upstream passage 121. A passage including the first upstream passage 121, the junction 124, and the downstream passage 123 has, for example, a circular shape in a cross section perpendicular to the direction D1 of the first passage.

[0032] The second upstream passage 122 includes a downstream end of the bypass passage 75 and forms a part of the bypass passage 75. The EGR gas that has bypassed the EGR cooler 80 thus flows into the second upstream passage 122.

[0033] The second upstream passage 122 is also a passage extending linearly along a direction D2 of the second passage. The direction D2 of the second passage is a direction intersecting the direction D1 of the first passage, strictly speaking, a direction perpendicular to the direction D1 of the first passage. That is, the direction of the second upstream passage 122 is the direction D2 of the second passage, and the second upstream passage 122 is arranged in a direction intersecting the first upstream passage 121 and the downstream passage 123.

[0034] The second upstream passage 122 has, for example, a circular shape in a cross-section perpendicular to the direction D2 of the second passage. The second upstream passage 122 has a smaller diameter than the first upstream passage 121 and the downstream passage 123.

[0035] As in the Fig. 2 to 4, the downstream passage 123 is connected to the downstream side of the gas flow of the first upstream passage 121 and the second upstream passage 122 via the connection point 124. That is, the connection point 124 is connected to each of the downstream side of the gas flow of the first upstream passage 121, the downstream side of the gas flow of the second upstream passage 122, and the upstream side of the gas flow of the downstream passage 123. In short, the connection point 124 is a space at which the first upstream passage 121 and the second upstream passage 122 join together among the passages formed in the housing 12.Thus, the EGR gas flowing out of the first upstream passage 121 and the EGR gas flowing out of the second upstream passage 122 combine and flow into the downstream passage 123.

[0036] As in Fig. As illustrated in Figure 4, the connection point 124 is formed, for example, as a space in which a space B1 obtained by virtually expanding the first upstream passage 121 along the direction of the first upstream passage 121 and a space B2 obtained by virtually expanding the second upstream passage 122 along the direction of the second upstream passage 122 overlap each other. The direction of the first upstream passage 121 is the direction D1 of the first passage, and the direction of the second upstream passage 122 is the direction D2 of the second passage. Fig. 4 and the Fig. 5, Fig. 12 and Fig. 15, which will be described later, the connection point 124 is marked with a dotted area.

[0037] As in the Fig. As illustrated in FIGS. 2 to 4, the EGR valve body 14 is disposed in the downstream passage 123 and rotates around an EGR valve axis CLa. The EGR valve body 14 rotates around the EGR valve axis CLa to open and close the downstream passage 123. In other words, the EGR valve body 14 rotates around the EGR valve axis CLa to increase or decrease the opening degree of the downstream passage 123. The EGR valve axis CLa is an axis along a valve shaft direction Da that is perpendicular to the first passage direction D1 and the second passage direction D2. The EGR valve axis CLa is located at the midpoint of the width of the downstream passage 123 in the second passage direction D2.

[0038] Specifically, the EGR valve body 14 is a throttle valve body, and is formed, for example, in a circular shape that conforms to the cross-sectional shape of the downstream passage 123 and in a plate shape along the valve shaft direction Da. In other words, the plate shape along the valve shaft direction Da is a plate shape with a thickness in a direction perpendicular to the EGR valve axis CLa.

[0039] The EGR valve shaft 15 is a rotating shaft rotatably supported by the housing 12. The EGR valve body 14 is fixed to the EGR valve shaft 15 by bolts or the like, and the EGR valve shaft 15 and the EGR valve body 14 rotate integrally around the EGR valve axis CLa. The EGR valve shaft 15 extends to both sides in the valve shaft direction Da from a fixed position of the EGR valve body 14 and is rotatably supported by the housing 12 on both sides of the EGR valve body 14 in the valve shaft direction Da.

[0040] The EGR valve biasing portion 16 functions as a return spring that biases the EGR valve body 14 and includes, for example, one or a plurality of torsion coil springs. The EGR valve biasing portion 16 is housed in the casing 12. The EGR valve biasing portion 16 constantly biases the EGR valve body 14 to one side in a circumferential direction Dac of the EGR valve axis CLa. The EGR valve biasing portion 16 thus constantly biases the EGR valve body 14 via the EGR valve shaft 15, so that the EGR valve body 14 returns to a predetermined reference rotational position. For example, when the EGR valve body 14 is at the reference rotational position, the EGR valve body 14 or the EGR valve shaft 15 is pressed against a stopper (not shown) which acts against the biasing force of the EGR valve biasing portion 16 in the circumferential direction Dac of the EGR valve axis CLa.Therefore, the EGR valve body 14 is returned to the reference rotational position of the EGR valve body 14 by the biasing force of the EGR valve biasing portion 16 when the motor 24 is not energized and not driven.

[0041] The reference rotational position of the EGR valve body 14 in the present embodiment is a rotational position at which the EGR valve body 14 fully opens the downstream passage 123, more specifically, a rotational position of the EGR valve body 14 shown in Fig. 2. That is, when the EGR valve body 14 is at the reference rotational position, the downstream passage 123 is fully opened. In the description of the present embodiment, the circumferential direction Dac of the EGR valve axis CLa is also referred to as "EGR valve circumferential direction Dac."

[0042] The fully open state of the downstream passage 123 means that the opening degree of the downstream passage 123 is 100%, that is, the opening degree of the downstream passage 123 is set to the maximum opening degree within the movable range of the EGR valve body 14. The fully closed state of the downstream passage 123 means that the opening degree of the downstream passage 123 is 0%, and in the fully closed state of the downstream passage 123, the flow of the EGR gas in the downstream passage 123 is blocked except for the leakage of the EGR gas. The fully open and fully closed states of the second upstream passage 122 are similar to the fully open and fully closed states of the downstream passage 123.

[0043] For example, in the present embodiment, the EGR valve body 14 does not rotate to one side in the circumferential direction Dac of the EGR valve from the reference rotational position of the EGR valve body 14, but is rotatable within a range of 90 degrees or less in the circumferential direction Dac of the EGR valve from the reference rotational position to the other side. As indicated by an arrow Ra, the opening degree of the downstream passage 123 decreases as the EGR valve body 14 rotates to the other side in the circumferential direction Dac of the EGR valve from the reference rotational position.

[0044] The bypass valve body 20 is arranged in the second upstream passage 122 and rotates about a bypass valve axis CLb, which is parallel to the EGR valve axis CLa. The bypass valve body 20 rotates about the bypass valve axis CLb to open and close the second upstream passage 122. In other words, the bypass valve body 20 rotates about the bypass valve axis CLb to increase or decrease the opening degree of the second upstream passage 122. The bypass valve axis CLb is located at the center of the width of the second upstream passage 122 in the direction D1 of the first passage. In the present embodiment, the valve shaft direction Da is the axial direction of the EGR valve axis CLa and is also the axial direction of the bypass valve axis CLb because the EGR valve axis CLa and the bypass valve axis CLb are parallel to each other.

[0045] More specifically, the bypass valve body 20 is a throttle valve body. For example, when the EGR valve body 14 is at the reference rotational position, the bypass valve body 20 fully opens the second upstream passage 122. Subsequently, when the EGR valve body 14 rotates to the other side in the circumferential direction Dac of the EGR valve from the reference rotational position, the bypass valve body 20 correspondingly rotates to one side in the circumferential direction Dbc of the bypass valve axis CLb, as indicated by an arrow Rb. The opening degree of the second upstream passage 122 decreases as the bypass valve body 20 rotates in the circumferential direction Dbc of the bypass valve axis CLb from the rotational position in Fig. 2, at which the second upstream passage 122 is fully open, turns to one side.

[0046] When the EGR valve body 14 is returned to the reference rotational position by the biasing force of the EGR valve biasing portion 16 when the engine 24 is not driven, at the same time, the bypass valve body 20 is returned to the rotational position at which the second upstream passage 122 is fully opened. Specifically, the rotational position at which the bypass valve body 20 fully opens the second upstream passage 122 is the rotational position of the bypass valve body 20 shown in Fig. 2. In the description of the present embodiment, the circumferential direction Dbc of the bypass valve axis CLb is also referred to as "circumferential direction Dbc of the bypass valve."

[0047] As in the Fig. 2 to 4, the bypass valve shaft 21 is a rotating shaft rotatably supported by the housing 12. The bypass valve body 20 is fixed to the bypass valve shaft 21 by screws or the like, and the bypass valve shaft 21 and the bypass valve body 20 rotate integrally around the bypass valve axis CLb. The bypass valve shaft 21 extends to both sides in the valve shaft direction Da from a fixed position of the bypass valve body 20 and is rotatably supported by the housing 12 on both sides of the bypass valve body 20 in the valve shaft direction Da.

[0048] The bypass valve biasing portion 22 includes, for example, a torsion coil spring or the like. The bypass valve biasing portion 22 is disposed outside the housing 12 and supported by the housing 12. The bypass valve biasing portion 22 constantly biases the bypass valve body 20 via the bypass valve shaft 21, causing the bypass valve body 20 to rotate to one side in the circumferential direction Dbc of the bypass valve.

[0049] The motor 24 is a drive source that rotates the EGR valve body 14 and the bypass valve body 20. The motor 24 is housed in the housing 12 and includes a motor body 241 fixed to the housing 12, a motor shaft 242 that rotates about a motor axis CLm, which is a rotation center of the motor 24, and a motor rotation sensor (not shown) that detects the rotation angle of the motor shaft 242. The motor axis CLm is parallel to the EGR valve axis CLa.

[0050] The motor 24 rotates the motor shaft 242 based on a signal from the control device 85 in Fig. 1, and outputs a signal to the control device 85 indicating the rotation angle of the motor shaft 242 detected by the motor rotation sensor. The rotation angle and direction of the motor shaft 242 are thus controlled by the control device 85. For example, when the EGR valve body 14 and the bypass valve body 20 are rotationally operated against the biasing force of the EGR valve biasing portion 16, the motor 24 generates a torque that overcomes the biasing force.

[0051] The motor 24 can also hold the rotation angle of the motor shaft 242 as it is energized, and when the motor 24 is not energized, the rotation angle of the motor shaft 242 is not held and the motor shaft 242 can rotate freely.

[0052] The motor shaft 242 is connected to the EGR valve shaft 15 via the speed reduction device 26 so as to be able to transmit power. The speed reduction device 26 includes a plurality of gears that are always meshed with each other, decelerates or decelerates the rotation of the motor shaft 242, and transmits the rotation to the EGR valve shaft 15. The speed reduction device 26 also includes a housing that forms part of the outer shell of the valve device 10, and the gears included in the speed reduction device 26 are housed in the housing.

[0053] The EGR valve shaft 15 is connected to the actuator portion 28 so as to be able to transmit power on one side in the valve shaft direction Da of the position of the EGR valve shaft 15 fixed to the EGR valve body 14, and is connected to the speed reduction device 26 so as to be able to transmit power on the other side in the valve shaft direction Da of the fixed position of the EGR valve body 14. The actuator portion 28 then connects the EGR valve shaft 15 and the bypass valve shaft 21 so as to be able to transmit power. Therefore, the rotational driving force of the motor 24 is transmitted to the motor shaft 242, the speed reducing device 26, the EGR valve shaft 15, the actuating portion 28 and the bypass valve shaft 21 in this order.

[0054] As in the Fig. 2 and Fig. As illustrated in Figure 5, the motor 24 and the bypass valve body 20 are arranged to oppose each other, with the joint 124 provided therebetween. The motor axis CLm is arranged side by side with the EGR valve axis CLa in the second passage direction D2, which is a direction perpendicular to the direction of the downstream passage 123 (i.e., the first passage direction D1). Fig. 5 and the Fig. 12 and Fig. 15, which will be described later, white arrows indicate the flow of the EGR gas.

[0055] As in the Fig. 2 and Fig. 3, the actuating portion 28 is an actuating mechanism that links the bypass valve body 20 to the rotational operation of the EGR valve body 14. Specifically, the actuating portion 28 of the present embodiment is configured as a cam-link mechanism and includes a cam 29 and an output rotary portion 30 driven by the rotation of the cam 29.

[0056] The cam 29 has a flat plate shape with a thickness in the valve shaft direction Da and is fixed to the EGR valve shaft 15. The cam 29 thus rotates integrally with the EGR valve body 14 and the EGR valve shaft 15 around the EGR valve axis CLa. The cam 29 has a cam track 291 formed on a peripheral edge of the cam 29. The cam track 291 is also referred to as a "profile of a cam 29." The cam 29 includes, for example, a cam through hole 29a penetrating in the valve shaft direction Da, which is the axial direction of the EGR valve axis CLa, as a section of the cam 29.

[0057] The output rotary portion 30 includes a lever 301 formed in a flat plate shape and having a thickness in the valve shaft direction Da, and a roller 302 as a cam follower rotatably supported by the lever 301. The roller 302 rotates relative to the lever 301 about an axis parallel to the bypass valve axis CLb, and the axis of the roller 302 is arranged to be radially shifted with respect to the bypass valve axis CLb.

[0058] The lever 301 is fixed to the bypass valve shaft 21. The lever 301 thus rotates integrally with the bypass valve body 20 and the bypass valve shaft 21 about the bypass valve axis CLb.

[0059] The bypass valve biasing portion 22 biases the bypass valve body 20, which is fixed to the bypass valve shaft 21, as described above, and also biases the lever 301, which is fixed to the bypass valve shaft 21. That is, the bypass valve biasing portion 22 constantly biases the lever 301 via the bypass valve shaft 21, so that the lever 301 rotates to one side in the circumferential direction Dbc of the bypass valve (see Fig. 4). As a result, the output rotary portion 30 rotates in an interlocking manner with the rotational operation of the cam 29, while causing the roller 302 to follow the cam track 291 because the roller 302 of the output rotary portion 30 is constantly pressed against the cam track 291.

[0060] In the valve device 10 configured as described above, as shown in the Fig. As illustrated in Figures 2 to 4, when the motor 24 is energized to rotate the motor shaft 242, the rotation of the motor shaft 242 is transmitted to the EGR valve shaft 15 via the speed reduction device 26, and the EGR valve shaft 15 rotates. Thus, the EGR valve body 14 and the cam 29 rotate integrally with the EGR valve shaft 15 about the EGR valve axis CLa.

[0061] The opening degree of the downstream passage 123 is changed by the rotation of the EGR valve body 14. When the cam 29 rotates, the lever 301 of the output rotary portion 30 rotates in an interlocking manner with the rotational operation of the cam 29, while causing the roller 302 to follow the cam track 291. The bypass valve body 20 and the bypass valve shaft 21 thus rotate integrally with the lever 301 about the bypass valve axis CLb. The opening degree of the second upstream passage 122 is changed by the rotation of the bypass valve body 20.

[0062] As illustrated above, according to the present embodiment, the motor 24 and the bypass valve body 20 are arranged to oppose each other with the joint 124 sandwiched therebetween, as shown in FIGS. Fig. 2 and Fig. 5. As a result, the motor 24, which rotates the EGR valve body 14 and the bypass valve body 20, is located away from the second upstream passage 122. For example, compared with a case where the motor 24 is located adjacent to the second upstream passage 122, the motor is less likely to be affected by the heat of the high-temperature EGR gas flowing through the second upstream passage 122. Thus, thermal damage due to the high-temperature EGR gas bypassing the EGR cooler 80 can be reduced.

[0063] In the valve device 10 of the present embodiment, since both the EGR valve body 14 and the bypass valve body 20 can be driven by one motor 24, it is possible to prevent an increase in the size of the valve device 10 and reduce the cost of the valve device 10.

[0064] The EGR gas that has bypassed the EGR cooler 80 is mixed with the EGR gas that has passed through the EGR cooler 80 at the junction 124 in the housing 12. On the downstream side of the gas flow of the junction 124, it is possible to prevent the generation of condensate by raising the temperature of the EGR gas to the dew point limit.

[0065] Since the EGR valve body 14 is provided in the downstream passage 123 and the bypass valve body 20 is provided in the second upstream passage 122, the flow rate of the EGR gas passing through the EGR cooler 80 can be adjusted without providing a valve body in the first upstream passage 121. Compared with a case where the valve body is provided in the first upstream passage 121, malfunction of the valve device 10 due to solidification of the condensate can be easily avoided even if condensate is generated. (1) According to the present embodiment, the motor axis CLm is parallel to the EGR valve axis CLa and is arranged side by side with the EGR valve axis CLa in a direction perpendicular to the direction of the downstream passage 123 (i.e., the direction D2 of the second passage). Thus, the EGR valve body 14 and the motor 24 that rotates the EGR valve body 14 can be arranged adjacent to each other at the shortest distance. As a result, for example, the volume required to provide the motor 24 can be reduced. (2) According to the present embodiment, the actuating portion 28 includes the cam 29 which rotates together with the EGR valve body 14 and includes the cam track 291, and the driven rotating portion 30 which rotates together with the bypass valve body 20 and includes the roller 302, as shown in FIGS. Fig. 2 and Fig. 3. The output rotary portion 30 rotates in an interlocking manner with the rotational operation of the cam 29 while causing the roller 302 to follow the cam track 291.

[0066] It is thus easy to link the EGR valve body 14 to the bypass valve body 20 depending on the shape of the cam track 291, so that the rotational amount of the EGR valve body 14 and the rotational amount of the bypass valve body 20, for example, have a non-linear relationship. In short, it is possible to flexibly adjust the passage-opening degree characteristic, that is, the relationship between the opening degree of the second upstream passage 122 and the opening degree of the downstream passage 123. Second embodiment

[0067] Next, a second embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described. In addition, the same or equivalent parts as those in the above-described embodiment will be omitted or simplified. The same applies to the description of embodiments described later.

[0068] As in Fig. As illustrated in Fig. 6, the present embodiment differs from the first embodiment in the structure of the adjusting portion 28. That is, the adjusting portion 28 of the present embodiment is configured not as a cam-link mechanism, but as a lever-link mechanism.

[0069] More specifically, the adjusting section 28 of the present embodiment does not include the cam 29 and the output rotary section 30 (see Fig. 2), but includes a first arm 31, a second arm 32 and a connecting lever 33.

[0070] The first arm 31 is fixed to the EGR valve shaft 15. The first arm 31 thus rotates integrally with the EGR valve body 14 and the EGR valve shaft 15 about the EGR valve axis CLa. The second arm 32 is fixed to the bypass valve shaft 21. The second arm 32 thus rotates integrally with the bypass valve body 20 and the bypass valve shaft 21 about the bypass valve axis CLb.

[0071] The connecting lever 33 connects the EGR valve body 14 and the bypass valve body 20. The connecting lever 33 thus includes one end portion 331 rotatably connected to the first arm 31 and the other end portion 332 rotatably connected to the second arm 32. One end portion 331 of the connecting lever 33 is arranged eccentrically from the EGR valve axis CLa, and the other end portion 332 of the connecting lever 33 is arranged eccentrically from the bypass valve axis CLb.

[0072] With such a configuration, the actuating portion 28 of the present embodiment links the bypass valve body 20 to the rotational operation of the EGR valve body 14 via the link lever 33. For example, when the EGR valve body 14 rotates in the EGR valve circumferential direction Dac from the reference rotational position to the other side as indicated by an arrow Rc, the bypass valve body 20 rotates in the bypass valve circumferential direction Dbc from a rotational position at which the second upstream passage 122 is fully opened to the other side as indicated by an arrow Rd.

[0073] (1) As described above, the adjusting section 28 according to the present embodiment links the bypass valve body 20 to the rotational operation of the EGR valve body 14 via the connecting lever 33, and thus, the length of the connecting lever 33 can be determined based on the distance between the EGR valve axis CLa and the bypass valve axis CLb. As a result, it is possible to flexibly adjust the distance between the EGR valve axis CLa and the bypass valve axis CLb.

[0074] The present embodiment is similar to the first embodiment except for the above description. In the present embodiment, the same effects as those of the first embodiment can be achieved with the same configuration as that of the first embodiment. Third embodiment

[0075] Next, a third embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described.

[0076] As in Fig. As illustrated in Fig. 7, the present embodiment differs from the first embodiment in the structure of the adjusting portion 28. That is, the adjusting portion 28 of the present embodiment is configured not as a cam-link mechanism, but as a gear-link mechanism.

[0077] More specifically, the adjusting section 28 of the present embodiment does not include the cam 29 and the output rotary section 30 (see Fig. 2), but includes a drive gear 35 and a driven gear 36.

[0078] The drive gear 35 is fixed to the EGR valve shaft 15. The drive gear 35 thus rotates integrally with the EGR valve body 14 and the EGR valve shaft 15 about the EGR valve axis CLa. The driven gear 36 is fixed to the bypass valve shaft 21. The driven gear 36 thus rotates integrally with the bypass valve body 20 and the bypass valve shaft 21 about the bypass valve axis CLb. Furthermore, the drive gear 35 and the driven gear 36 are always in mesh with each other.

[0079] With such a configuration, the actuating portion 28 of the present embodiment links the bypass valve body 20 to the rotational operation of the EGR valve body 14 via the drive gear 35 and the driven gear 36. For example, when the EGR valve body 14 rotates in the EGR valve circumferential direction Dac from the reference rotational position to the other side as indicated by an arrow Re, the bypass valve body 20 rotates in the bypass valve circumferential direction Dbc from a rotational position at which the second upstream passage 122 is fully opened to the other side as indicated by an arrow Rf.

[0080] (1) As described above, the adjusting portion 28 according to the present embodiment includes the drive gear 35 that rotates together with the EGR valve body 14, and the driven gear 36 that rotates together with the bypass valve body 20 and meshes with the drive gear 35. Since the torque fluctuation of the motor 24 that rotates the EGR valve body 14 and the bypass valve body 20 is small, good controllability is achieved at the time of the rotating operation of the EGR valve body 14 and the bypass valve body 20.

[0081] The present embodiment is similar to the first embodiment except for the above description. In the present embodiment, the same effects as those of the first embodiment can be achieved with the same configuration as that of the first embodiment. Fourth embodiment

[0082] Next, a fourth embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described.

[0083] As in Fig. 8, the cam 29 in the present embodiment includes a cam projection 292. The cam projection 292 projects to one side in the valve shaft direction Da from a peripheral edge 29b of the cam through hole 29a (see Fig. 3). The cam protrusion 292 extends along the peripheral edge 29b of the cam through hole 29a. The cam protrusion 292 is provided, for example, over the entire circumference of the cam through hole 29a and is formed in a tubular shape extending in the valve shaft direction Da.

[0084] (1) The cam 29 includes the cam protrusion 292 as described above, and thus, it is possible to increase the surface area of ​​a portion that comes into contact with air when the valve is operated. As a result, it is possible to enhance the cooling effect of dissipating the heat of the valve device 10 to the outside.

[0085] For example, when the cam 29 rotates together with the EGR valve shaft 15 as indicated by an arrow Rg, an air flow A1 is generated relative to the cam lobe 292, and the air flow A1 strikes the cam lobe 292, so that heat dissipation from the cam 29 is promoted.

[0086] The present embodiment is similar to the first embodiment except for the above description. In the present embodiment, the same effects as those of the first embodiment can be achieved with the same configuration as that of the first embodiment. Fifth embodiment

[0087] Next, a fifth embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described.

[0088] As in Fig. 9, the cam 29 in the present embodiment includes a plurality of cam protrusions 293, and the lever 301 of the driven rotary portion 30 includes a plurality of driven protrusions 303. The cam protrusions 293 are provided on a side surface 29c of the cam 29, which is on one side in the valve shaft direction Da (see Fig. 3) and protrude to one side in the valve shaft direction Da from one side surface 29c. The cam protrusions 293 are arranged at intervals parallel to each other and extend along one side surface 29c of the cam 29.

[0089] The output protrusions 303 are provided on a side surface 301a of the lever 301 formed on one side in the valve shaft direction Da, and protrude to one side in the valve shaft direction Da from the one side surface 301a. The output protrusions 303 are arranged at intervals parallel to each other and extend along the one side surface 301a of the lever 301. The one side surface 29c of the cam 29 corresponds to a surface of a cam in the present disclosure, and the one side surface 301a of the lever 301 corresponds to a surface of an output rotary portion in the present disclosure.

[0090] (1) The cam protrusions 293 and the driven protrusions 303 are provided as described above, and thus it is possible to increase the surface area of ​​a portion that comes into contact with air when the valve is operated. As a result, it is possible to enhance the cooling effect of dissipating the heat of the valve device 10 to the outside.

[0091] For example, when the cam 29 rotates together with the EGR valve shaft 15, as indicated by an arrow Rh, an air flow A2 is generated relative to the cam protrusions 293, and the air flow A2 impinges on the cam protrusions 293, so that heat dissipation from the cam 29 is promoted. The same applies in a case where the lever 301 rotates, and heat dissipation from the lever 301 is promoted.

[0092] The present embodiment is similar to the first embodiment except for the above description. In the present embodiment, the same effects as those of the first embodiment can be achieved with the same configuration as that of the first embodiment. Sixth embodiment

[0093] Next, a sixth embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described.

[0094] As in Fig. As illustrated in FIG. 10, the EGR valve body 14 includes a one-side end 141 provided in a lateral direction of the EGR valve body on one side, which is a direction perpendicular to the EGR valve axis CLa and along the EGR valve body 14 having a flat plate shape, and an other-side end 142 provided in the lateral direction of the EGR valve body on the other side. In this respect, the present embodiment is similar to the first embodiment.

[0095] An expanded space B2 is assumed. The expanded space B2 is obtained by virtually expanding the second upstream passage 122 along the direction of the second upstream passage 122. In this case, in a state in which the EGR valve body 14 fully opens the downstream passage 123, the end 141 on one side of the EGR valve body 14 is located on the upstream side of the gas flow of a side edge B2a of the expanded space B2 on the downstream passage 123 side. The state in which the EGR valve body 14 fully opens the downstream passage 123 is a state in which the EGR valve body 14 is at the reference rotational position. In this respect, too, the present embodiment is similar to the first embodiment. In Fig. 10, a part of the EGR valve body 14 at the reference rotational position is indicated by a dash-two-dash line L1.

[0096] However, in the present embodiment, the rotation direction when the EGR valve body 14 rotates in a direction to close the downstream passage 123 is indicated by an arrow Ri, and the rotation direction when the EGR valve body 14 rotates in a direction to open the downstream passage 123 is opposite to the arrow Ri. In this respect, the present embodiment is different from the first embodiment.

[0097] More specifically, in the present embodiment, the motor 24 always rotates the EGR valve body 14 as indicated by the arrow Ri when the EGR valve body 14 rotates in the direction to close the downstream passage 123 from a state in which the EGR valve body 14 fully opens the downstream passage 123. That is, in a case where the end 141 on a side shown in Fig. 10 is located on the upstream side of the gas flow of the side edge B2a, when the EGR valve body 14 rotates in the direction to close the downstream passage 123, the motor 24 always rotates the EGR valve body 14 in a direction in which the end 141 on one side is moved away from the second upstream passage 122.

[0098] On the other hand, the engine 24 always rotates the EGR valve body 14 in the direction opposite to the arrow Ri when the EGR valve body 14 rotates in the direction toward the fully open state of the downstream passage 123 to open the downstream passage 123. That is, in a case where the end 141 on a side located in Fig. 10 is located on the upstream side of the gas flow of the side edge B2a, when the EGR valve body 14 rotates in the direction to open the downstream passage 123, the motor 24 always rotates the EGR valve body 14 in a direction in which the end 141 on one side approaches the second upstream passage 122.

[0099] In other words, the motor 24 rotates the EGR valve body 14 to one side in the circumferential direction Dac of the EGR valve from the reference rotational position in the direction to close the downstream passage 123. When the EGR valve body 14 rotates from the reference rotational position in the direction to close the downstream passage 123, the motor 24 does not rotate the EGR valve body 14 to the other side in the circumferential direction Dac of the EGR valve from the reference rotational position.

[0100] In the present embodiment, as the EGR valve body 14 rotates to one side in the circumferential direction Dac of the EGR valve from the fully open state of the downstream passage 123, the opening degree of the downstream passage 123 decreases while the end 141 on one side is moved away from the second upstream passage 122. The motor 24 then rotates the EGR valve body 14 within a rotation range R1 from a fully closed rotation position at which the EGR valve body completely closes the downstream passage 123 to a rotation position at which the EGR valve body 14 rotates 90 degrees to the other side in the circumferential direction Dac of the EGR valve.

[0101] Since the EGR valve body 14 is rotationally driven as described above, the EGR gas cooled by the EGR cooler 80 and flowing as indicated by an arrow E1 does not directly impact the EGR valve body 14. That is, the EGR gas cooled and flowing as indicated by the arrow E1 mixes with the EGR gas bypassing the EGR cooler 80 and flowing as indicated by an arrow E2, so that its temperature rises, and then impacts the EGR valve body 14 as indicated by an arrow E3. The EGR valve body 14 is thus hardly cooled.

[0102] As a result, it is possible to suppress the generation of condensate due to EGR gas having high temperature and high humidity hitting the EGR valve body 14. Since the EGR valve axis CLa is arranged close to the junction 124 to reduce the interval between the EGR valve body 14 and the bypass valve body 20 while suppressing the generation of condensate, the valve device 10 can be downsized.

[0103] A first comparative example is used here, which is Fig. 11 is illustrated to explain the reason why the generation of condensate is suppressed in the present embodiment. In a valve device 90 of the first comparative example, the EGR valve body 14 rotates in a direction opposite to the direction in the present embodiment from the fully open state of the downstream passage 123, as shown in Fig. 11 is illustrated.

[0104] More specifically, in the first comparative example, when the EGR valve body 14 rotates in the direction to close the downstream passage 123 from a state in which the EGR valve body 14 fully opens the downstream passage 123, the engine 24 always rotates the EGR valve body 14 as indicated by an arrow Rj. That is, in a case where the end 141 on a side shown in Fig. 11 is located on the upstream side of the gas flow of the side edge B2a, when the EGR valve body 14 rotates in the direction to close the downstream passage 123, the motor 24 always rotates the EGR valve body 14 in a direction in which the end 141 on one side approaches the second upstream passage 122.

[0105] On the other hand, the engine 24 of the first comparative example always rotates the EGR valve body 14 in the direction opposite to the arrow Rj when the EGR valve body 14 rotates in the direction toward the fully open state of the downstream passage 123 to open the downstream passage 123. That is, in a case where the end 141 on a side located in Fig. 11, is located on the upstream side of the gas flow of the side edge B2a, when the EGR valve body 14 rotates in the direction to open the downstream passage 123, the motor 24 always rotates the EGR valve body 14 in a direction in which the end 141 on one side is moved away from the second upstream passage 122. The first comparative example is similar to the present embodiment except for these points.

[0106] In the first comparative example, the EGR valve body 14 is likely to be in a position that prevents the EGR gas cooled by the EGR cooler 80 and flowing as indicated by an arrow E4 from being mixed with the EGR gas bypassing the EGR cooler 80 and flowing as indicated by an arrow E5, as shown in Fig. 11. The EGR gas cooled by the EGR cooler 80 and flowing as indicated by the arrow E4 often directly impacts the EGR valve body 14, and thus the EGR valve body 14 is easily cooled. As a result, condensate Wc is likely to be generated due to the high-temperature and high-humidity EGR gas impacting the EGR valve body 14 being cooled.

[0107] On the other hand, in the present embodiment, as described above, the EGR valve body 14 is less likely to be cooled compared with the first comparative example, and thus it is possible to suppress generation of condensate due to the EGR gas having high temperature and high humidity hitting the EGR valve body 14.

[0108] Since the direction in which the EGR valve body 14 is rotationally operated is limited in the present embodiment as described above, various configurations of the valve device 10 are also changed in accordance with this limitation. For example, the EGR valve biasing portion 16 (see Fig. 3) In the present embodiment, the EGR valve body 14 is constantly displaced not to one side but to the other in the circumferential direction Dac of the EGR valve axis CLa. In addition, the shape of the cam 29 of the actuating portion 28 is not similar to that of the first embodiment, and the cam 29 is formed in accordance with a direction in which the EGR valve body 14 is rotationally operated.

[0109] In the present embodiment, the first upstream passage 121 corresponds to one passage of the present disclosure, and the second upstream passage 122 corresponds to the other passage of the present disclosure.

[0110] The present embodiment is similar to the first embodiment except for the above description. In the present embodiment, the same effects as those of the first embodiment can be achieved with the same configuration as that of the first embodiment.

[0111] Although the present embodiment is a modification based on the first embodiment, the present embodiment may be combined with any of the second to fifth embodiments described above. Seventh embodiment

[0112] Next, a seventh embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described.

[0113] As in Fig. 12, the present embodiment differs from the first embodiment in the arrangement of the first upstream passage 121, the second upstream passage 122 and the bypass valve body 20.

[0114] Specifically, in the present embodiment, the second upstream passage 122, the junction 124, and the downstream passage 123 are connected in series from the upstream side of the gas flow in the order of the second upstream passage 122, the junction 124, and the downstream passage 123 along the direction D1 of the first passage, forming a linearly extending passage. That is, the direction of the second upstream passage 122 and the direction of the downstream passage 123 are the same, and both are the direction D1 of the first passage. The second upstream passage 122 is connected in series to the downstream passage 123 via the junction 124.

[0115] The first upstream passage 121 extends linearly along the direction D2 of the second passage. That is, the direction of the first upstream passage 121 is the direction D2 of the second passage, and the first upstream passage 121 is arranged in a direction intersecting the second upstream passage 122 and the downstream passage 123. The first upstream passage 121 is connected to the downstream passage 123 via the junction 124. Moreover, the direction D2 of the second passage in the present embodiment is a direction intersecting the direction D1 of the first passage, strictly speaking, a direction perpendicular to the direction D1 of the first passage, as in the first embodiment.

[0116] The bypass valve body 20 of the present embodiment is disposed in the second upstream passage 122 and rotates around the bypass valve axis CLb, which is parallel to the EGR valve axis CLa, as in the first embodiment. The bypass valve axis CLb, which is the rotation center of the bypass valve body 20, is arranged side by side with the EGR valve axis CLa, which is the rotation center of the EGR valve body 14, in the first passage direction D1. The bypass valve shaft 21 is also arranged side by side with the EGR valve shaft 15 in the first passage direction D1.

[0117] The EGR valve body 14 of the present embodiment is arranged away from the joint 124 without entering the joint 124.

[0118] Since the present embodiment differs from the first embodiment in terms of the relative positional relationship between the EGR valve axis CLa and the bypass valve axis CLb, as described above, various configurations of the valve device 10 are also changed in accordance with this difference. For example, the shape of the cam 29 (see Fig. 2) the adjusting portion 28 is not that of the first embodiment, and the cam 29 is formed in accordance with the relative positional relationship between the EGR valve axis CLa and the bypass valve axis CLb.

[0119] The present embodiment is similar to the first embodiment except for the above description. In the present embodiment, the same effects as those of the first embodiment can be achieved with the same configuration as that of the first embodiment.

[0120] Although the present embodiment is a modification based on the first embodiment, the present embodiment may be combined with any of the second to fifth embodiments described above. Eighth embodiment

[0121] Next, an eighth embodiment will be described. In this embodiment, differences from the seventh embodiment will be mainly described.

[0122] As in Fig. As illustrated in Figure 13, the present embodiment is an embodiment obtained by combining the seventh embodiment with the sixth embodiment. Specifically, the EGR valve body 14 of the present embodiment includes the end 141 on one side and the end 142 on the other side, as in the sixth embodiment. In this respect, the present embodiment is similar to the seventh embodiment.

[0123] An expanded space B3 is assumed. The expanded space B3 is obtained by virtually expanding the first upstream passage 121 along the direction of the first upstream passage 121 (that is, the direction D2 of the second passage). In this case, in a state where the EGR valve body 14 fully opens the downstream passage 123, the end 141 on one side of the EGR valve body 14 is located on the upstream side of the gas flow of a side edge B3a of the expanded space B3 on the downstream passage 123 side. In this respect, the present embodiment differs from the seventh embodiment. The state in which the EGR valve body 14 fully opens the downstream passage 123 is a state in which the EGR valve body 14 is at the reference rotational position, as in the seventh embodiment. In addition, in Fig. 13 similar to Fig. 10, a part of the EGR valve body 14 at the reference rotational position is indicated by the dash-two-dash line L1.

[0124] In the present embodiment, the rotation direction when the EGR valve body 14 rotates in a direction to close the downstream passage 123 is indicated by the arrow Ri, and the rotation direction when the EGR valve body 14 rotates in a direction to open the downstream passage 123 is opposite to the arrow Ri.

[0125] More specifically, in the present embodiment, the motor 24 always rotates the EGR valve body 14 as indicated by the arrow Ri when the EGR valve body 14 rotates in the direction to close the downstream passage 123 from a state in which the EGR valve body 14 fully opens the downstream passage 123. That is, in a case where the end 141 on a side shown in Fig. 13 is located on the upstream side of the gas flow of the side edge B3a, when the EGR valve body 14 rotates in the direction to close the downstream passage 123, the motor 24 always rotates the EGR valve body 14 in a direction in which the end 141 on one side is moved away from the first upstream passage 121.

[0126] On the other hand, the engine 24 always rotates the EGR valve body 14 in the direction opposite to the arrow Ri when the EGR valve body 14 rotates in the direction toward the fully open state of the downstream passage 123 to open the downstream passage 123. That is, in a case where the end 141 on a side located in Fig. 13 is located on the upstream side of the gas flow of the side edge B3a, when the EGR valve body 14 rotates in the direction to open the downstream passage 123, the motor 24 always rotates the EGR valve body 14 in a direction in which the end 141 on one side approaches the first upstream passage 121.

[0127] In other words, the motor 24 rotates the EGR valve body 14 to one side in the circumferential direction Dac of the EGR valve from the reference rotational position in the direction to close the downstream passage 123. When the EGR valve body 14 rotates from the reference rotational position in the direction to close the downstream passage 123, the motor 24 does not rotate the EGR valve body 14 to the other side in the circumferential direction Dac of the EGR valve from the reference rotational position.

[0128] In the present embodiment, as the EGR valve body 14 rotates to one side in the circumferential direction Dac of the EGR valve from the fully open state of the downstream passage 123, the opening degree of the downstream passage 123 decreases while the end 141 on one side is moved away from the first upstream passage 121. The motor 24 then rotates the EGR valve body 14 within a rotation range R1 from a fully closed rotation position at which the EGR valve body completely closes the downstream passage 123 to a rotation position at which the EGR valve body 14 rotates 90 degrees to the other side in the circumferential direction Dac of the EGR valve.

[0129] Since the EGR valve body 14 is operated in a rotating manner as described above, the EGR gas cooled by the EGR cooler 80 (see Fig. 12) and thus, as indicated by an arrow E6, does not flow directly onto the EGR valve body 14. That is, the EGR gas that is cooled and flows as indicated by an arrow E6 is mixed with the EGR gas that bypasses the EGR cooler 80 and flows as indicated by an arrow E7, so that its temperature rises, and then hits the EGR valve body 14, as indicated by an arrow E8. The EGR valve body 14 is thus hardly cooled.

[0130] Furthermore, in the present embodiment, it is possible to suppress the generation of condensate due to EGR gas with high temperature and high humidity hitting the EGR valve body 14, as in the sixth embodiment. Since the EGR valve axis CLa is arranged close to the junction 124 to reduce the interval between the EGR valve body 14 and the bypass valve body 20 while suppressing the generation of condensate, the valve device 10 can be downsized.

[0131] A second comparative example is used here, which is Fig. 14 is illustrated to explain the reason why the generation of condensate is suppressed in the present embodiment. In a valve device 92 of the second comparative example, the EGR valve body 14 rotates in a direction opposite to the direction in the present embodiment from the fully open state of the downstream passage 123, as shown in Fig. 14 is illustrated.

[0132] More specifically, in the second comparative example, when the EGR valve body 14 rotates in the direction to close the downstream passage 123 from a state in which the EGR valve body 14 fully opens the downstream passage 123, as in the first comparative example in Fig. 11.

[0133] On the other hand, the motor 24 of the second comparative example always rotates the EGR valve body 14 in the direction opposite to the arrow Rj, as in the first comparative example in Fig. 11, when the EGR valve body 14 rotates toward the fully open state of the downstream passage 123 to open the downstream passage 123. The second comparative example is similar to the present embodiment except for these points.

[0134] In the second comparative example, the EGR valve body 14 is likely to be in a position that prevents the EGR gas cooled by the EGR cooler 80 and flowing as indicated by an arrow E9 from being mixed with the EGR gas bypassing the EGR cooler 80 and flowing as indicated by an arrow E10, as shown in Fig. 14. Furthermore, in the second comparative example, the EGR gas cooled by the EGR cooler 80 and flowing as indicated by the arrow E9 often directly impacts the EGR valve body 14, and thus the EGR valve body 14 is easily cooled, as in the first comparative example. As a result, condensate Wc is likely to be generated due to the high-temperature and high-humidity EGR gas impacting the EGR valve body 14 being cooled.

[0135] On the other hand, in the present embodiment, as described above, the EGR valve body 14 is less likely to be cooled compared with the second comparative example, and thus it is possible to suppress generation of condensate due to the EGR gas having high temperature and high humidity hitting the EGR valve body 14.

[0136] Since the direction in which the EGR valve body 14 is rotationally operated is limited in the present embodiment as described above, various configurations of the valve device 10 are also changed in accordance with this limitation. For example, the EGR valve biasing portion 16 (see Fig. 3) In the present embodiment, the EGR valve body 14 is constantly advanced in the circumferential direction Dac of the EGR valve axis CLa not to one side but to the other. In addition, the shape of the cam 29 of the actuating portion 28 is not similar to that of the seventh embodiment, and the cam 29 is formed in accordance with a direction in which the EGR valve body 14 is rotationally driven.

[0137] In the present embodiment, the first upstream passage 121 corresponds to the other passage of the present disclosure, and the second upstream passage 122 corresponds to the one passage of the present disclosure.

[0138] The present embodiment is similar to the seventh embodiment except for the above description. In the present embodiment, the same effects as those of the seventh embodiment can be achieved by using the same configuration as that of the seventh embodiment. Other embodiments (1) In each of the above-described embodiments, the fuel used in the internal combustion engine system 70 is Fig. 1, hydrogen, but this is an example. For example, the internal combustion engine system 70 may use fossil fuel such as gasoline as fuel to generate power. (2) In the third embodiment described above, the driven gear 36 is directly engaged with the drive gear 35 as shown in Fig. 7, but this is an example. For example, an intermediate gear may be additionally provided between the drive gear 35 and the driven gear 36, and the driven gear 36 may be indirectly engaged with the drive gear 35 via the intermediate gear. (3) In the first embodiment described above, the motor axis CLm is arranged side by side with the EGR valve axis CLa in the direction D2 of the second passage as shown in Fig. 5, but the arrangement of the motor 24 is not limited thereto. It is only necessary that the motor 24 and the bypass valve body 20 are arranged such that they are opposite to each other with the connecting point 124 interposed therebetween, and as shown, for example, in Fig. 15, the motor 24 may be arranged at a position indicated by a dash-two-dash line M1. Alternatively, the motor 24 may be arranged at a position indicated by a dash-two-dash line M2. (4) In the seventh embodiment described above, the motor 24 is arranged on the side of the downstream passage 123 opposite to the side on which the first upstream passage 121 is provided in the direction D2 of the second passage, as shown in Fig. 12, but this is an example. The motor 24 may, for example, be arranged at a position indicated by a dash-two-dash line M3 in Fig. 12. That is, the motor 24 may be disposed on the side of the downstream passage 123 on which the first upstream passage 121 is provided in the direction D2 of the second passage. Even with this arrangement of the motor 24, the motor 24 and the bypass valve body 20 are arranged to oppose each other with the joint 124 sandwiched therebetween. (5) In the first embodiment described above, the cam track 291 includes a part of the peripheral edge of the cam 29, but it may also include, for example, a groove or an elongated hole provided in the cam 29 instead of the peripheral edge of the cam 29, as shown in Fig. 2 is illustrated. (6) The present disclosure is not limited to the above-described embodiments, and various modifications may be made. In addition, the above-described embodiments are not independent of each other, but may be appropriately combined unless the combination is obviously impossible.

[0139] Additionally, in each of the above embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in a case where it is expressly stated that the elements are essential and a case where the elements are obviously essential in principle. When a numerical value such as the number, numerical value, amount, range, or the like of the constituent elements of the embodiment is set forth, the numerical value in each of the above embodiments is not limited to a specific number unless otherwise specified as essential or obviously limited to the specific number.In each of the above embodiments, the material, shape, positional relationship, and the like are not limited when referring to the material, shape, positional relationship, and the like of the constituent elements and the like, unless otherwise specified or fundamentally limited to specific materials, shapes, positional relationships, and the like.

Claims

[1] A valve device that increases or decreases a flow rate of EGR gas, the valve device comprising: a housing (12) containing: a first upstream passage (121) into which the EGR gas cooled by an EGR cooler (80) flows, a second upstream passage (122) into which the EGR gas flows, bypassing the EGR cooler, a connection point (124) connected to both a downstream side of the gas flow of the first upstream passage and a downstream side of the gas flow of the second upstream passage, and a downstream passage (123) connected to the first upstream passage and the second upstream passage via the connection point; a bypass valve body (20) provided in the second upstream passage and opening and closing the second upstream passage; an EGR valve body (14) provided in the downstream passage and rotating about an EGR valve axis (CLa) to open and close the downstream passage; a motor (24) which drives the EGR valve body in rotation; and an actuating section (28) which links the bypass valve body with a rotary operation of the EGR valve body, wherein the motor and the bypass valve body are arranged such that they are opposite each other, the connection point being inserted between the motor and the bypass valve body, the bypass valve body rotates about a bypass valve axis (CLb) to open and close the second upstream passage, the actuating section includes a cam (29) which rotates with the EGR valve body and has a cam track (291), and an output rotary section (30) which rotates with the bypass valve body and has a cam follower (302), and the output rotary portion rotates in an intermeshing manner upon rotational operation of the cam while causing the cam follower to follow the cam track, wherein the cam includes a cam through hole (29a) penetrating in an axial direction (Da) of the EGR valve axis, and the cam includes a cam projection (292) protruding from a peripheral edge (29b) of the cam through hole in the axial direction of the EGR valve axis and extending along the peripheral edge of the cam through hole. [2] A valve device that increases or decreases a flow rate of EGR gas, the valve device comprising: a housing (12) containing: a first upstream passage (121) into which the EGR gas cooled by an EGR cooler (80) flows, a second upstream passage (122) into which the EGR gas flows, bypassing the EGR cooler, a connection point (124) connected to both a downstream side of the gas flow of the first upstream passage and a downstream side of the gas flow of the second upstream passage, and a downstream passage (123) connected to the first upstream passage and the second upstream passage via the connection point; a bypass valve body (20) provided in the second upstream passage and opening and closing the second upstream passage; an EGR valve body (14) provided in the downstream passage and rotating about an EGR valve axis (CLa) to open and close the downstream passage; a motor (24) which drives the EGR valve body in rotation; and an actuating section (28) which links the bypass valve body with a rotary operation of the EGR valve body, wherein the motor and the bypass valve body are arranged such that they are opposite each other, the connection point being inserted between the motor and the bypass valve body, the bypass valve body rotates about a bypass valve axis (CLb) to open and close the second upstream passage, the actuating section has a cam (29) which rotates with the EGR valve body and a cam track (291) and an output rotary portion (30) which rotates with the bypass valve body and has a cam follower (302), and the output rotary portion rotates in an intermeshing manner upon rotational operation of the cam while causing the cam follower to follow the cam track, wherein the cam includes a cam projection (293) provided on a surface (29c) of the cam and protruding in an axial direction (Da) of the EGR valve axis, and the output rotary portion includes an output projection (303) provided on a surface (301a) of the output rotary portion and protruding in an axial direction (Da) of the bypass valve axis. [3] Valve device according to claim 1 or 2, wherein a center of rotation (CLm) of the engine is parallel to the EGR valve axis, and the rotation center of the engine and the EGR valve axis are aligned in a direction (D2) perpendicular to a direction (D1) of the downstream passage. [4] Valve device according to one of claims 1 to 3, wherein one of the first upstream passage and the second upstream passage is connected in series with the downstream passage in a same direction as a direction (D1) of the downstream passage via the connection point, another of the first upstream passage and the second upstream passage is connected to the downstream passage via the connection point in a direction (D2) intersecting the direction of the downstream passage, and is defined as another passage, the EGR valve body has one end (141) on one side in a direction perpendicular to the EGR valve axis and in a direction toward which the EGR valve body extends, the end on one side is located upstream in a state in which the EGR valve body fully opens the downstream passage with respect to a side edge (B2a, B3a) which is an edge of an expanded space (B2, B3) and is an edge located closest to the downstream passage, the expanded space is obtained by virtually expanding the other passage toward a direction of the other passage, and the engine rotates the EGR valve body in a direction in which the end on one side is moved away from the other passage in a case where the end on one side is upstream with respect to the side edge when the EGR valve body rotates in one direction to close the downstream passage.

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