Air saving device

Abstract

The utility model relates to a gas saving device. Water is effectively prevented from entering a shell of a motor from the periphery of a shaft of the motor for moving a valve element for opening and closing a bypass passage of a throttle device. The utility model relates to a throttle device (1). A throttle device (1) is provided with: a main body member (2, 50, 60) in which are formed a main passage (7) having a throttle valve (14) and a bypass passage (70) bypassing the throttle valve; a valve body (110) that opens and closes the bypass passage; an actuator (108) that moves the valve body by means of a shaft (127); and a housing (112) that is disposed in a housing section (58) formed in the main body member and houses the actuator. A through hole (125) which is formed in the housing and through which the shaft passes; and a pressure fluctuation suppressing mechanism (200, 68, 210) which suppresses the pressure fluctuation in the housing part.

Description

Technical Field

[0001] The present technology relates to an air-saving device. Background Art

[0002] Vehicles such as ships, motorcycles, and bicycles with prime movers equipped with engines are usually equipped with a throttle device for controlling the amount of air intake to the engine. In addition to a main passage (hole) equipped with a throttle valve, the throttle device is sometimes provided with a bypass passage for idling that bypasses the throttle valve. In the bypass passage, a valve for controlling the idling speed is usually provided.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-167201

[0004] Patent Document 2: Japanese Patent Application Publication No. 2020-060269 Utility Model Content

[0005] Problems to be solved by utility models

[0006] When the valve core that opens and closes the bypass passage is moved by a motor, the area around the shaft protruding from the motor housing may not be completely sealed. In this case, air containing moisture may enter and cause rust on motor parts such as the winding. In particular, when the engine stops, the heat of the engine and the heat of the motor stop, so negative pressure is generated inside the housing, air is easily sucked in, and moisture is easily condensed inside the housing. In addition, in the case of a throttle device installed on a ship, the possibility of air with high humidity and salt concentration entering is very high, and the problem of rust becomes serious.

[0007] Various methods have been proposed for sealing around the shaft protruding from the motor housing. For example, Japanese Patent Publication No. 2022-167201 discloses that in order to prevent moisture from invading the coil housing, a bellows-shaped cover is always used to cover the area around the shaft protruding from the coil housing. However, if a pressure change occurs inside the housing, the bellows will deform to a large extent and there is a high possibility of cracking, so a sufficient sealing function cannot be expected. Assuming that even if the sealing function can be maintained, in order to obtain a larger driving force to overcome the pressure change, a powerful motor is required, which increases the cost.

[0008] Japanese Patent Application No. 2020-060269 discloses that a sealing member is arranged around a shaft protruding from a coil housing to a flow path, and when the solenoid valve is opened, the valve core is seated on the sealing member. However, when this structure is applied to a stepping motor, there is a high possibility of step loss before the valve core reaches the fully open position, and therefore, a sufficient sealing function cannot be expected.

[0009] Therefore, it is desirable to solve at least one of the above problems and effectively suppress the intrusion of moisture from the periphery of the shaft of the motor of the damper device into the housing.

[0010] Solutions for solving problems

[0011] One technical solution is a throttle device, wherein the throttle device comprises: a main component, which forms a main passage with a throttle valve and a bypass passage bypassing the throttle valve; a valve core, which opens and closes the bypass passage; an actuator, which moves the valve core with the aid of an axis; a housing, which is arranged in a housing formed in the main component and accommodates the actuator; a through hole formed in the housing and for the shaft to pass through; and a pressure change suppression mechanism, which suppresses pressure changes in the housing.

[0012] According to an embodiment of the present invention, the pressure fluctuation suppression mechanism includes a diaphragm disposed facing the bypass passage.

[0013] According to the technical solution, the main component includes a first main component forming the main passage and a second main component forming the accommodating portion, the bypass passage is formed between the first main component and the second main component, the diaphragm is arranged in the thinned portion of the second main component facing the bypass passage, and the pressure change suppression mechanism includes a connecting hole connecting the thinned portion and the accommodating portion.

[0014] According to the technical solution, a sealing component is provided around the through hole, and the sealing component contacts the valve core or the housing to seal the through hole when the valve core moves in the opening direction. The actuator has a stepping motor, and a stop component is provided between the valve core and the housing. The stop component specifies the fully open position of the valve core by abutting against the valve core or the housing. When the valve core moves in the opening direction, before the stop component abuts against the valve core or the housing, the sealing component contacts the valve core or the housing to seal the through hole.

[0015] Another technical solution is a throttle device, wherein the throttle device comprises: a main body member, which forms a main passage with a throttle valve and a bypass passage bypassing the throttle valve; a valve core, which opens and closes the bypass passage; a stepping motor, which moves the valve core by means of a shaft; a housing, which is arranged in a housing formed in the main body member and accommodates the stepping motor; and a through hole, which is formed in the housing and allows the shaft to pass through. The throttle device also comprises: a sealing member, which is arranged around the through hole, and when the valve core moves in the opening direction, the sealing member contacts the valve core or the housing to seal the through hole; and a stopper member, which is arranged between the valve core and the housing, and the stopper member specifies the fully open position of the valve core by contacting the valve core or the housing, and when the valve core moves in the opening direction, before the stopper member contacts the valve core or the housing, the sealing member contacts the valve core or the housing to seal the through hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of a throttle device according to one embodiment, using a plane cut through the center line of the main passage (hole) and the center line of the throttle shaft.

[0017] Figure 2 The throttle device is cut by a plane passing through the center line of the main passage (hole) and perpendicular to the center line of the throttle shaft. Figure 1 Cross-sectional view viewed from the bottom side.

[0018] Figure 3 This is a three-dimensional diagram in which the IDU main body is decomposed from the air-saving main body of the air-saving device.

[0019] Figure 4 is from Figure 1 Observe the top view of the solar term body from the upper side.

[0020] Figure 5 This is a perspective view of the bottom side of the IDU main body.

[0021] Figure 6 It is a cross-sectional view of the throttle device cut along a plane passing through the center line of the ISC valve and along the bypass passage.

[0022] Figure 7 This is a three-dimensional diagram of the stepper motor and valve core of the ISC valve.

[0023] Figure 8 This is a diagram schematically showing an external pressure change suppression device as another embodiment.

[0024] Fig. 9 The figure schematically shows the ISC valve when the valve body is in the closed position.

[0025] Fig.10 This is a diagram schematically showing the ISC valve when the valve element moves in the opening direction and contacts the lip seal.

[0026] Fig.11 This is a diagram schematically showing the ISC valve when the valve element contacts the stopper member and reaches the fully open position.

[0027] Fig.12 It is a figure which shows the lip seal attached to the valve body as another embodiment.

[0028] Fig.13 This is a diagram showing an O-ring attached to a motor case as still another embodiment.

[0029] Fig.14 This is a diagram showing an O-ring attached to a valve body as still another embodiment.

[0030] Fig.15 This is a diagram showing an elastic bellows attached to a motor case as still another embodiment.

[0031] Description of Reference Numerals

[0032] 1. Throttle device; 2. Throttle body; 6. Hole forming portion; 7. Main passage (hole); 9. Throttle shaft; 12, 13. Elastic sealing member; 14. Throttle valve; 26. IDU joint portion; 26a. Matching surface; 28. Inlet hole; 30. Outlet hole; 33. Valve seat; 37. Passage groove; 42. Through hole; 50. IDU body; 50a. Matching surface; 51. ISC valve; 58. Accommodating portion; 60. IDU cover; 68. Thinning portion; 70. Bypass passage; 72. Motor fitting portion; 75. Flange portion; 108, stepper motor; 110, valve core; 112, motor housing; 125, through hole; 127, shaft; 129, screw portion; 133, sealing surface; 136, nut; 138, spring; 180, gasket; 200, diaphragm; 202, peripheral frame; 210, connecting hole; 220, space; 230, container; 232, bellows; 234, connecting pipe; 300, 304, lip seal; 302, stop member; 306, 308, O-ring; 310, bellows. DETAILED DESCRIPTION

[0033] Hereinafter, various embodiments of the present technology will be described with reference to the drawings.

[0034] Vessels (outboard and inboard), motorcycles, bicycles with prime movers and other vehicles and transport machinery equipped with engines usually have an intake pipe connected to the engine and a control system for controlling the amount of air intake to the engine. Figure 1 The air-throttling device 1 is shown. Figure 1 , Figure 3The up-down direction of FIG. 1 is drawn so as to coincide with the up-down direction of the air throttle device 1 mounted on a ship as one embodiment.

[0035] [Throttle body and throttle valve]

[0036] like Figure 1 As shown, the throttle device 1 has a throttle body 2 made of metal (e.g., aluminum alloy), and the throttle body 2 has a hole forming portion 6 that forms a substantially cylindrical through-going main passage 7 (hole). The upstream side of the main passage 7 is connected to the atmosphere, and an air cleaner can be provided. The downstream side of the main passage 7 is connected to the engine via an intake pipe such as an intake manifold. The air sucked from the atmosphere passes through the main passage 7 of the throttle device 1 and is taken into the engine.

[0037] like Figure 1 , Figure 2 As shown in FIG. 1 , a butterfly-shaped disc-shaped throttle valve 14 is arranged inside the main passage 7, which is supported by the throttle shaft 9 and opens and closes the main passage 7. The throttle valve 14 is fixed to the throttle shaft 9 by a screw 15 or the like. The throttle shaft 9 is rotatably held on the throttle body 2 and crosses the main passage 7 in the radial direction. The throttle valve 14 is rotated in the closed position ( Figure 2 The throttle shaft 9 is rotated between the position shown in the figure and the open position (not shown) to control the intake amount through the main passage 7. The throttle shaft 9 passes through the shaft through holes 10, 11 formed in the throttle body 2 on both sides of the throttle valve 14, and is held rotatably by bearings 19, 20. Each shaft through hole 10, 11 is sealed by an elastic sealing member 12, 13 such as a lip seal arranged between the throttle shaft 9 and the wall surface of each shaft through hole 10, 11.

[0038] [Throttle lever]

[0039] like Figure 1 As shown, one end of the throttle shaft 9 protrudes from the throttle body 2, and a throttle lever 17 is coupled to the protruding portion. The throttle lever 17 is connected to the throttle handle operated by the driver via a transmission member such as a cable. A return spring 18 composed of a torsion coil spring is installed between the throttle lever 17 and the throttle body 2. The return spring 18 applies force to the throttle valve 14 in the closing direction by means of the throttle lever 17. The throttle lever 17 is fixed to a stopper 21 (see FIG. 2 ) on the outside of the throttle body 2. Figure 3 ) limits rotation in the closing direction.

[0040] [Intake device unit]

[0041] like Figure 1As shown, the throttle device 1 has an intake device unit (IDU) 3 installed on the throttle body 2. For the IDU 3, valves, various sensors and other devices required for intake control (hereinafter referred to as "intake devices") are assembled into a resin IDU body 50 to form a module. The IDU body 50 has a connector insertion portion 97, and an external connector is inserted into the connector insertion portion 97. The external connector is used to electrically connect the intake device to an external electronic control unit (ECU). The ECU receives output signals from various detection devices such as sensors and switches, and sends control signals to actuators such as motors.

[0042] like Figure 3 As shown, the throttle body 2 has a flange-shaped IDU coupling portion 26, and the IDU coupling portion 26 has a mating surface 26a for coupling to the IDU3. The mating surface 26a is formed, for example, in a direction orthogonal to the throttle shaft 9 (i.e., the rotation axis of the throttle valve 14). The IDU body 50 has a mating surface 50a that is coupled to the mating surface 26a of the IDU coupling portion 26 of the throttle body 2. In order to enable the disassembly and assembly of the IDU3, for example, a plurality of protrusions 44 are formed on the periphery of the IDU coupling portion 26 of the throttle body 2, and correspondingly, a protrusion 62 is also formed on the periphery of the IDU body 50. The fastening bolts (not shown) passing through the through holes 62a of each protrusion 62 of the IDU body 50 are screwed into the threaded holes 44a of the corresponding protrusions 44 of the throttle body 2, thereby coupling the IDU body 50 to the throttle body 2.

[0043] The air intake device is assembled from the side opposite to the throttle body 2 into the receiving portion 58 recessed from the opposite side of the mating surface 50a. The IDU body 50 is combined with an IDU cover 60 (see Figure 1 , Figure 6 ), so that the receiving portion 58 of the IDU body 50 equipped with the air intake device is closed. By selecting an appropriate bonding method, or configuring an elastic sealing member between the IDU body 50 and the IDU cover 60 as needed, the internal space of the IDU 3 is sealed relative to the outside.

[0044] [Bypass Path]

[0045] like Figure 6 As shown in FIG. 1 , the bypass passage 70 that bypasses the throttle valve 14 is formed by combining the IDU body 50 with the throttle body 2. The bypass passage 70 branches from the main passage 7 on the upstream side of the throttle valve 14 and merges with the main passage 7 again on the downstream side of the throttle valve 14. Specifically, the IDU joint portion 26 of the throttle body 2 is formed with a passage groove 37 that is deeply recessed from the mating surface 26a (see also FIG. 1 ). Figure 3The inlet hole 28 and the outlet hole 30 are respectively opened from the passage groove 37 through the hole forming portion 6 to the wall surface of the main passage 7. As a result, a part of the intake air flowing in the main passage 7 can flow from the inlet hole 28 through the bypass passage 70 and out of the outlet hole 30 to the main passage 7 (see also Figure 1 , Figure 2 ).

[0046] [ISC valve]

[0047] like Figure 6 As shown, the throttle device 1 is provided with an idle speed control (ISC) valve 51 for adjusting the intake air amount passing through the bypass passage 70. The ISC valve 51 is mainly controlled by the ECU when the engine is idling. The ISC valve 51 is installed in the housing portion 58 of the IDU body 50. The ISC valve 51 has a fully closed position ( Figure 6 The valve core 110 opens and closes the bypass passage 70 by linearly moving between a full open position (dashed line) and a full open position (solid line), and an actuator that moves the valve core 110 by means of a shaft 127. The actuator can be, for example, a stepping motor 108, but as another embodiment, it can also be a motor other than a stepping motor such as a DC motor or a brushless motor. The throttle body 2 has a valve seat 33 for the valve core 110 to sit on the bottom of the passage groove 37 (the inflow portion of the outlet hole 30). The valve core 110 has a sealing surface 133 of a pointed and tapered shape opposite to the valve seat 33.

[0048] The stepper motor 108 has a motor housing 112. Although not shown in the figure, the motor housing 112 has a stator having a winding and a rotor having a magnet. The stator has a coil frame made of resin for holding the winding. The coil frame is integrally provided with a terminal support portion 120 protruding from an opening provided on the side of the motor housing 112. The terminal 117 (see FIG. 1 ) is held by the terminal support portion 120 by insert molding. Figure 7 The terminal 117 of the stepping motor 108 is in electrical contact with a terminal plate connected to the terminal of the connector insertion portion 97. The shaft 127 is rotatably supported by the motor housing 112 via a bearing (not shown), and the rotor is coupled to the shaft 127.

[0049] The stepping motor 108 is connected to the motor fitting portion 72 (see also Figure 3 An O-ring 63 (see also FIG. 1 ) is disposed between the motor housing 112 and the wall surface of the motor fitting portion 72. Figure 7 ). As a result, the internal space of the IDU 3 is sealed relative to the bypass passage 70.

[0050] [Threaded connection between the screw part and the nut]

[0051] like Figure 6As shown in FIG. 1 , the shaft 127 protrudes outward from the through hole 125 of the motor housing 112, and a screw portion 129 is formed at the protruding portion. A nut 136 having a threaded hole is pressed into the recessed hole 254 of the valve core 110. The screw portion 129 of the shaft 127 is threadedly engaged with the nut 136. For the valve core 110, a groove 134a (see FIG. 1 ) extending in the axial direction of the ISC valve 51 is used. Figure 7 ) and the linear protrusion 76 enable the valve core 110 to slide relative to the IDU body 50 and stop rotating. Specifically, a linear protrusion 76 is formed on the inner peripheral surface of the motor fitting portion 72, and a groove 134a is formed on the outer peripheral surface of the flange portion 134 of the valve core 110 corresponding thereto. As a result, when the stepper motor 108 rotates, the valve core 110 moves axially by means of the threaded engagement of the shaft 127 and the nut 136. When the valve core 110 moves forward, the outlet hole 30 is closed, and when it moves backward, the outlet hole 30 is opened.

[0052] As another embodiment not shown, the actuator of the ISC valve 51 may be an actuator that moves the valve element 110 by advancing and retreating the shaft 127 itself. For example, an actuator other than a motor such as a motor or an electromagnetic solenoid having a screw and a nut inside a housing may be used.

[0053] [spring]

[0054] like Figure 6 As shown, the motor fitting portion 72 has a cylindrical protrusion 74 protruding from the mating surface 50a into the passage groove 37 of the throttle body 2. A circular enlarged portion 32 (see FIG. 3 ) for accommodating the protrusion 74 of the motor fitting portion 72 is formed at the end of the passage groove 37 of the throttle body 2. Figure 3 ). An inwardly protruding flange portion 75 is formed at the end of the cylindrical protruding portion 74. The valve core 110 protrudes into the passage groove 37 through the opening formed by the inwardly protruding flange portion 75. A spring 138 composed of a coil spring is installed between the flange portion 134 of the valve core 110 and the inwardly protruding flange portion 75 at the bottom of the motor fitting portion 72. One end of the spring 138 is fitted into an annular recess 134b formed in an annular shape in the flange portion 134 of the valve core 110.

[0055] [Throttle position sensor]

[0056] like Figure 1As shown, a throttle position sensor for detecting the direction (angle) of the throttle valve 14 can also be provided in the throttle device 1. The throttle position sensor is mounted on the accommodating portion 58 of the IDU body 50. The throttle position sensor is configured, for example, to include a sensor rotor 143 fixed to the end of the throttle shaft 9, and the position of the brush of the sensor rotor 143 is electrically detected by a resistor plate arranged on the surface of the wiring substrate 55. A through portion 64 for accommodating the end of the throttle shaft 9 is formed in the IDU body 50. In this way, the internal space of the IDU is connected to the throttle body 2, but as described above, it is sealed relative to the main passage 7 by a sealing member 12 arranged around the throttle shaft 9.

[0057] [Pressure sensor]

[0058] A pressure sensor (not shown) for measuring the pressure of the intake air flowing in the main passage 7 may be provided in the throttle device 1. The pressure sensor is disposed in the housing portion 58 of the IDU body 50, for example, mounted on the wiring substrate 55. Figure 5 As shown, a through portion 78 penetrating to the mating surface 50a is formed on the bottom surface of the accommodating portion 58 of the IDU body 50, and the main body of the pressure sensor is arranged in the through portion 78. A sealing member (not shown) is arranged between the main body of the pressure sensor and the through portion 78. Figure 1 As shown, the throttle body 2 is formed with a communication hole 38 that passes through the hole forming portion 6 from the mating surface 26a and opens on the wall surface (on the downstream side of the throttle valve 14) of the main passage 7. The communication hole 38 is formed via a communication passage 40 (also refer to Figure 3 , Figure 5 ) and communicates with the through-portion 78. In this way, the detection portion of the pressure sensor is arranged in a space communicated with the main passage 7 of the throttle body 2, but since a sealing member is arranged around the main body of the pressure sensor, the internal space of the IDU 3 is not communicated with the main passage 7.

[0059] [Temperature sensor]

[0060] A temperature sensor (not shown) for detecting the temperature of the intake air flowing through the main passage 7 may also be provided in the throttle device 1. The temperature sensor is mounted in the housing portion 58 of the IDU body 50. Figure 5 As shown in FIG. 1 , the IDU body 50 is formed with a closed top end tube 81 protruding from the mating surface 50a, and a detection portion of the temperature sensor is inserted into the tube 81. Figure 2 , Figure 3As shown in FIG. 1 , a through hole 42 for the temperature sensor is formed in the throttle body 2, which penetrates the hole forming portion 6 from the mating surface 26a and opens on the wall surface of the main passage 7 (on the upstream side of the throttle valve 14), and the cylinder 81 of the IDU body 50 is fitted into the through hole 42. In this way, the detection part of the temperature sensor is located at a position closer to the inside than the wall surface of the main passage 7, but since the top end of the cylinder 81 is closed, the internal space of the IDU 3 is not connected to the main passage 7.

[0061] [Gasket]

[0062] like Figure 6 As shown, the mating surface 26a of the throttle body 2 and the mating surface 50a of the IDU body 50 can be sealed by one or more elastic sealing members such as a gasket 180 that are formed in the shape of a hole or a recessed portion that opens on these mating surfaces. The gasket 180 can be installed in the fitting groove 90 (see Figure 5 When the IDU body 50 and the throttle body 2 are combined using such a gasket 180, the holes and recesses opened on the mating surface 50a of the IDU body 50 and the mating surface 26a of the throttle body 2 are sealed relative to the outside of the throttle device 1 or relative to other holes and recesses.

[0063] [Pressure change suppression mechanism]

[0064] When the housing 58 of the IDU body 50 is sealed by various sealing members, the pressure inside the motor housing 112 and inside the housing 58 connected thereto tends to change, especially due to the temperature difference caused by the heat generation and heat dissipation of the stepper motor 108 of the ISC valve 51. In particular, when negative pressure is generated inside the motor housing 112 and air containing moisture is sucked in, there is a possibility that the parts of the stepper motor 108 will rust. Therefore, a mechanism that suppresses such pressure changes can be provided in the throttle device 1. In order to suppress the pressure change, for example, a structure that allows the volume change of the inside of the IDU 3 or the space connected thereto can be provided.

[0065] [Diaphragm and communication hole]

[0066] like Figure 6 As shown in FIG. 1 , as an embodiment, the diaphragm 200 can be arranged so as to face the bypass passage 70. The diaphragm 200 is a film having elasticity and can be formed of an elastic material (elastomer). For example, the diaphragm 200 can be arranged in the thinned portion 68 (see also FIG. 1 ) formed so as to be recessed from the mating surface 50a of the IDU body 50. Figure 5). The thinning portion 68 is usually provided for the purpose of reducing material costs, for example, and is formed in the IDU body 50 in an area corresponding to a portion of the passage groove 37 of the throttle body 2 (a portion other than the circular enlarged portion 32). The diaphragm 200 can be installed, for example, by fixing the outer peripheral frame 202 to the wall surface of the thinning portion 68. A connecting hole 210 (or a larger connecting space) is formed in the IDU body 50, which passes from the accommodating portion 58 to the thinning portion 68. Thus, the smaller space 220 formed by the thinning portion 68 and the diaphragm 200 is connected to the accommodating portion 58.

[0067] As another embodiment not shown in the figure, the diaphragm can also be arranged in a manner facing the main passage 7. In this case, the diaphragm can also be installed by fixing its peripheral portion to the surrounding structure by using an appropriate method such as bonding or welding. In addition, a connecting hole penetrating the IDU body 50 and the throttle body 2 is appropriately provided. In short, it is sufficient to partially divide the space communicating with the main passage 7 and the bypass passage 70 and the space communicating with the accommodating portion 58 by using a diaphragm.

[0068] As another embodiment not shown in the figure, a diaphragm may be arranged in such a manner as to divide the housing portion 58 closed by the IDU cover 60, and the space in the divided two spaces where the motor housing 112 is not arranged may be communicated with the outside (atmosphere) by a connecting hole. As another embodiment not shown in the figure, a part of the IDU body 50 or the IDU cover 60 forming the housing portion 58 may be formed by a diaphragm. In the case of this last embodiment, a connecting hole is not required.

[0069] [External pressure change suppression device]

[0070] like Figure 8 As shown in the figure, as another embodiment, a container 230 with a variable volume and communicating with the storage portion 58 of the IDU body 50 can be provided outside the IDU body 50. As such a container, a container having a telescopic structure such as a bellows 232 is exemplified. Such a container with a variable volume can be connected to the hole penetrating the IDU body 50 by using a connecting pipe 234, or can be connected by being provided as a container directly covering the hole penetrating the IDU body 50.

[0071] [Stopper and elastic sealing member]

[0072] like Figures 9 to 11As shown, an elastic sealing member is arranged around the through hole 125 of the motor housing 112 through which the shaft 127 passes, and contacts the valve core 110 to seal the through hole 125 when the valve core 110 moves in the opening direction (upward in the figure). The elastic sealing member is, for example, annular or cylindrical. The elastic sealing member can be, for example, a lip seal 300 formed of an elastic material (elastomer). A stop member 302 is provided between the valve core 110 and the motor housing 112, and specifies the fully open position of the valve core 110 by abutting against the valve core 110. When the valve core 110 moves in the opening direction, before the stop member 302 abuts against the valve core 110, the lip seal 300 contacts the valve core 110 to seal the periphery of the through hole 125 ( Fig.10 The stopper member 302 has rigidity, while the lip seal 300 has low rigidity in terms of material or structure. The stopper member 302 may be annular, or may be a plurality of stopper members in the form of dots or arcs discretely arranged around the through hole 125. Fig.12 As shown, as another embodiment, a lip seal 304 can also be installed on the valve element 110.

[0073] like Figure 13 to Figure 15 As another embodiment, the elastic sealing member can be, for example, an O-ring 306, 308 formed of an elastic material, a bellows (elastic bellows) 310 formed of an elastic material, etc. In this case, the elastic sealing member can be Fig.13 The O-ring 306 can be installed on the motor housing 112 as well as Fig.14 The stopper member is mounted on the valve core 110 like an O-ring 308. Although not shown, the stopper member may be formed on the valve core 110 instead of the motor housing 112.

[0074] The lip seal 300 does not perform any sealing when the valve core 110 is in the closed position, and the sealing function is performed only after the valve core 110 moves in the opening direction and contacts the lip seal 300. However, when the engine is stopped, the valve core 110 is kept in the fully open position. Therefore, even if the heat of the stepper motor 108 is dissipated and the motor housing 112 becomes negative pressure, the periphery of the through hole 125 is sealed, and air containing moisture is not sucked into the motor housing 112. Assuming that the periphery of the shaft is always covered with a bellows regardless of the position of the valve core 110, if the pressure in the sealed housing fluctuates, a load is applied to the bellows through the gap around the through hole 125, and cracks are likely to occur. Assuming that the bellows does not crack, in order to overcome the pressure change and move the valve core 110, the stepper motor 108 needs to be relatively strong, and the cost becomes high. However, in the case of providing the diaphragm 200 as described above, the stopper member 302 can be omitted, but the method of providing the stopper member 302 is more effective. Conversely, when the stopper member 302 is provided, the diaphragm 200 can be omitted, but the embodiment in which the diaphragm 200 is also provided is more effective.

[0075] By rotating the stepper motor 108 in the opening direction while the valve core 110 is in contact with the stopper member 302, the stepper motor 108 is caused to lose step, so that the ISC valve 51 can be initialized based on the fully open position of the valve core 110. Assuming that there is no stopper member 302 and only an elastic sealing member such as a rubber sheet is used to support the fully open position, the following problems will occur. First, in the case where the elastic material of the elastic sealing member is relatively hard (large elastic modulus), sometimes even if the stepper motor 108 loses step, the elastic sealing member hardly follows and cannot play a sealing function. In order to move the valve core 110 to the fully open position without losing to the elastic sealing member, for example, the stepper motor 108 needs to be relatively strong, which increases the cost. Conversely, in the case where the elastic material of the elastic sealing member is relatively soft, when the engine stops, when the valve core stays in the fully open position for a long time, the elastic sealing member remains in a state of being deformed to a large extent, resulting in material fatigue and loss of restoring force. On the other hand, as in the above-mentioned embodiment, the fully open position is defined by the stopper member 302, so that even if the elastic sealing member is set as the lip seal 300 and is sufficiently soft, the lip seal 300 is not compressed to the limit, and thus fatigue does not occur. In addition, when the ISC valve 51 is initialized at the fully open position, even if the valve element 110 slightly returns to the closing direction due to a step loss, the lip seal 300 will follow and will not lose the sealing function.

[0076] Various embodiments have been described above, but the present technology is not limited to these embodiments, and a person skilled in the art can make various changes, improvements, additions, and omissions.

Claims

1. A gas-saving device, characterized in that: The air-saving device has: a main body member formed with a main passage having a throttle valve and a bypass passage bypassing the throttle valve; A valve core, which opens and closes the bypass passage; an actuator that moves the valve core via a shaft; a housing, which is disposed in a receiving portion formed in the main body member and receives the actuator; a through hole formed in the housing for the shaft to pass through; and A pressure fluctuation suppression mechanism suppresses pressure fluctuations in the housing portion.

2. The air-saving device according to claim 1, characterized in that: The pressure fluctuation suppression mechanism includes a diaphragm disposed facing the bypass passage.

3. The air-saving device according to claim 2, characterized in that: The main body member includes a first main body member forming the main passage and a second main body member forming the accommodation portion, the bypass passage is formed between the first main body member and the second main body member, and the diaphragm is arranged at a thinned portion of the second main body member facing the bypass passage. The pressure fluctuation suppression mechanism includes a communication hole that connects the thinned portion and the accommodation portion.

4. The air-saving device according to claim 1, characterized in that: A sealing member is provided around the through hole, and when the valve element moves in the opening direction, the sealing member contacts the valve element or the housing to seal the through hole. The actuator includes a stepping motor. A stopper member is provided between the valve body and the housing, and the stopper member defines a fully open position of the valve body by abutting against the valve body or the housing. When the valve element moves in the opening direction, the sealing member comes into contact with the valve element or the housing to seal the through hole before the stopper member comes into contact with the valve element or the housing.

5. A gas-saving device, characterized in that: The air-saving device has: a main body member formed with a main passage having a throttle valve and a bypass passage bypassing the throttle valve; A valve core, which opens and closes the bypass passage; a stepper motor, which moves the valve core via a shaft; A housing, which is disposed in a receiving portion formed in the main body component and receives the stepping motor; a through hole formed in the housing for the shaft to pass through; a sealing member provided around the through hole, the sealing member coming into contact with the valve element or the housing to seal the through hole when the valve element moves in the opening direction; and a stopper member disposed between the valve core and the housing, the stopper member defining a fully open position of the valve core by abutting against the valve core or the housing, When the valve element moves in the opening direction, the sealing member comes into contact with the valve element or the housing to seal the through hole before the stopper member comes into contact with the valve element or the housing.

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