JP4152303B2 - Rotary valve - Google Patents

Description

  The present invention relates to a rotary valve arranged between fluid flow paths and capable of adjusting the flow rate and shutting off the flow of fluid flowing in the fluid flow path, and particularly used as a leading air control valve for a stratified scavenging two-cycle engine. It is related with the rotary valve which can do.

  Conventionally, butterfly-type throttle valves and rotary valves have been used as valve bodies that are arranged between fluid flow paths and adjust the flow rate and shut off the flow rate of fluid flowing in the fluid flow path. In particular, a leading air control device using a butterfly-type throttle valve as a leading air control valve of a stratified scavenging two-cycle engine (see, for example, Patent Document 1) and a two-cycle engine carburetor using a rotary throttle valve ( For example, Patent Document 2) has been proposed by the present applicant.

  The leading air control device described in Patent Document 1 has a configuration as shown in FIG. That is, the carburetor 60 having the throttle valve 61 is attached to the first intake passage 62 connected to the intake port 57 opened to the cylinder 50 via the insulator 67, and the intake side of the carburetor 60 is connected to the air cleaner 63. Connected. A second intake passage 64 connected to the first intake passage 62 and a leading air passage 65 parallel to the second intake passage 64 are provided in the insulator 67. One end of the leading air passage 65 is connected to the air cleaner 63, and the other end is connected to a scavenging port 58 that opens to the cylinder 50 via a connecting pipe 68. A butterfly type air control valve 66 for controlling the air flow rate is provided in the leading air passage 65, and is interlocked with the throttle valve 61 provided in the second intake passage 64.

  As shown in FIG. 7, the air-fuel mixture is compressed in the cylinder chamber A at the top dead center position of the piston 51. In this state, when the air-fuel mixture is ignited by the spark plug 52, the air-fuel mixture explodes and pushes down the piston 51 downward. At this time, the scavenging port 58 and the scavenging passage 59 are filled with leading air purified by the air cleaner 63, and the crank chamber 53 is mixed with fuel and air purified by the air cleaner 63 by the carburetor 60. The air / fuel mixture is full.

  When the piston 51 descends, the intake port 57 is first closed, and the air-fuel mixture that has filled the crank chamber 53 is compressed. Next, as the piston 51 descends, the exhaust port 54 opens, and the combustion gas passes through the exhaust passage 55 and is discharged to the outside through the muffler 56. Subsequently, the scavenging port 58 is opened, and the leading air filled in the scavenging port 58 and the scavenging passage 59 flows into the cylinder chamber A due to the pressure of the compressed air-fuel mixture in the crank chamber 53, and the remaining combustion gas is removed. The gas is discharged from the exhaust port 54.

  Thereafter, the air-fuel mixture in the crank chamber 53 flows into the cylinder chamber A. At this time, since the piston 51 is raised and the exhaust port 54 is closed, the air-fuel mixture is prevented from being discharged to the outside. The amount of hydrocarbon HC contained in the gas is reduced, and the waste of fuel can be reduced.

  The amount of the air-fuel mixture that passes through the vaporizer 60 is controlled by the throttle valve 61, and the amount of the leading air that passes through the air passage 65 can be controlled by the air control valve 66. Since the throttle valve 61 and the air control valve 66 are interlocked with each other, the balance between the amount of air-fuel mixture and the amount of leading air can always be maintained, and combustion control in an optimum state can be performed.

  Thus, in the invention described in Patent Document 1, since the air control valve 66 is provided in the air passage 65 for leading air in the insulator 67, the air control is performed without taking up a space in a limited space. The valve 66 can be provided, the overall length L of the entire engine shown in FIG. 1 can be shortened, and a light and compact layered scavenging two-cycle engine can be obtained.

  In addition, since an air control valve as a component part conventionally provided between the air purifier and the vaporizer is not required, the number of parts is small, and the vaporizer can be used as it is, so the cost can be reduced. There is an effect that can be done.

  Next, the carburetor for a two-cycle engine described in Patent Document 2 has a configuration as shown in FIG. That is, the air passage 83 is connected to a portion of the scavenging passage 82 that communicates between the scavenging port 81 and the crank chamber 87 of the two-cycle engine, close to the scavenging port 81 side. The air passage 83 is provided with a check valve 84 that allows air to flow toward the scavenging passage 82.

  An air control valve 71 that controls the amount of air supplied from the air cleaner 72 to the air passage 83 is provided, and a rotary throttle valve 73 is provided as the air control valve 71. In addition, an air / fuel mixture is supplied from the air purifier 72 to the crank chamber 87 through the carburetor 70 and the check valve 86. In order to open and close the throttle valve 73 of the air control valve 71 in conjunction with the opening and closing operation of the throttle valve 74 in the carburetor 70, an operation lever 88 for driving the throttle valve 74 and a lever (not shown) for operating the throttle valve 73 are provided. They are connected by a connecting rod 75 so that their mutual distance can be adjusted.

  The two-cycle engine carburetor described in Patent Document 2 also exhibits the same operation as the leading air control device described in Patent Document 1. When the air-fuel mixture compressed at the upper part of the piston 77 is ignited by the spark plug 78, the piston 77 moves down by the explosion energy of the air-fuel mixture. By the downward movement of the piston 77, the combustion gas is discharged from the discharge port 79 to the outside air through the exhaust muffler 80, and then the scavenging port 81 is opened, and the scavenging port is opened by the pressure of the air-fuel mixture in the compressed crank chamber 87. The leading air filled in 81 and the scavenging passage 82 flows into the cylinder chamber B, and the remaining combustion gas is discharged from the exhaust port 79.

  Next, the air-fuel mixture in the crank chamber 87 flows into the cylinder chamber B through the scavenging passage 82 and the scavenging port 81. The air that flows into the cylinder chamber B from the scavenging port 81 and the air mixture that flows into the cylinder chamber B from the crank chamber 87 via the scavenging passage 82 and the scavenging port 81 are not mixed and the leading air flows first. Then, the air-fuel mixture flows in.

  Next, when the piston 77 moves up from the bottom dead center and reaches the vicinity of the top dead center, the crank chamber 87 is in a negative pressure state, the check valve 86 of the intake port 85 is opened, and is generated by the carburetor 70. The air-fuel mixture is sucked into the crank chamber 87 from the intake port 85.

  Further, the check valve 84 is opened by the negative pressure in the crank chamber 87, and air is sucked into the crank chamber 87 from the air purifier 72 through the air control valve 71, the air passage 83, the check valve 84, and the scavenging passage 82. . Thus, when the piston 77 almost reaches the top dead center, the crank chamber 87 is filled with the air-fuel mixture, and the scavenging passage 82 and the scavenging port 81 are filled with only air.

  In the invention described in Patent Document 2, the adjustment hole of the operation lever 88 or the adjustment hole of the lever (not shown) of the air control valve 71 is selected, and the throttle valve 74 of the carburetor 70 and the throttle valve 73 of the air control valve 71 are selected. Can be engaged with each other. Thereby, it is comprised so that the optimal opening degree of the throttle valve 73 in the air control valve 71 with respect to the opening degree of the throttle valve 74 can be obtained.

For this reason, only the air that has flown into the cylinder chamber B earlier in the scavenging stroke can flow out to the exhaust port 79 together with the combustion gas, and the air-fuel mixture that flows into the cylinder chamber B after the leading air enters the cylinder chamber B. Since it can be made to stay, scavenging efficiency can be made high. As a result, the amount of unburned components (HC) contained in the exhaust gas can be reduced, and fuel can be used effectively without waste, so that the output of the two-cycle engine can be increased. ing.
JP 2000-328945 A JP-A-9-268918

  In the invention described in Patent Document 1, since the butterfly throttle valve and the throttle valve shaft are used in the leading air control device, it is necessary to use a screw or the like to connect the throttle valve and the throttle valve shaft. Met. For this reason, if the length of the air passage on the intake side or cylinder side from the valve installation position is long, it will be difficult for the tool to enter and assembly work etc. will be difficult, so the valve placement position will be a position where the tool can be assembled. It will be limited. Further, since it is necessary to support the throttle valve shaft at both ends, the machining position accuracy of both holes for supporting the throttle valve shaft is required.

  In the invention described in Patent Document 2, the rotary throttle valve 5 is used for the air control valve C. However, in order to provide the rotary throttle valve 5 with a sealing property, the valve outer peripheral surface and the body inner peripheral surface are provided. It is required to make the interval between and the minimum. In order to form a minimum fixed interval, it is necessary to form the outer peripheral surface of the valve and the inner diameter surface of the body by high-precision processing.

  In the present invention, as the rotary valve, it is possible to use a rotary valve that is intentionally provided with a gap without minimizing the distance between the outer peripheral surface of the valve and the inner diameter of the body. The purpose is to provide a rotary valve.

The objects of the present invention can be achieved by the inventions described in claims 1 to 4 .
That is, in the present invention, as described in claim 1, in the rotary valve configured as the leading air control valve of the stratified scavenging two-cycle engine, the rotary valve has a valve and a body, A gap is formed between the valve outer peripheral surface, and sealing means for sealing the gap is disposed between the body inner diameter portion and the valve outer peripheral surface,
The sealing means has a lip portion that is elastically supported, and is provided on the outer peripheral surface of the valve or the inner diameter portion of the body, and the inner diameter portion of the body that contacts the lip portion by high-pressure air acting on the rotary valve. A rotary valve characterized in that the lip portion is pressed and urged toward the outer peripheral surface of the valve is the main feature.

Further, in the present invention as described in claim 2, wherein the rotary valve has no mainly characterized by comprising provided on the insulator that is connected to the intake port of the stratified scavenging two-cycle engine.

  Furthermore, in the present invention, as described in claim 3, the main feature is that the lip portion is in contact with the outer peripheral surface of the valve.

  Furthermore, in the present invention, as described in claim 4, the main feature is that the lip portion is in contact with the body inner diameter portion.

  In the present invention, in the rotary valve in which a gap is formed between the body inner diameter portion and the valve outer peripheral surface, the sealing means for sealing between at least one fluid flow path connected to the rotary valve and the gap is provided as the body inner diameter. It is characterized in that it is arranged between the part and the outer peripheral surface of the valve.

  As a result, the rotary valve that is intentionally formed with a gap between the outer peripheral surface of the valve and the inner diameter surface of the body that is intentionally large enough to prevent malfunction due to thermal deformation, assembly deformation, or biting of dust. Can be used. In addition, the sealing means disposed between the body inner diameter portion and the valve outer peripheral surface can surely seal the gap between the valve outer peripheral surface and the body inner diameter surface and the fluid flow path provided with the rotary valve.

  For this reason, a rotary valve capable of reducing the cost can be easily used as a throttle valve without requiring special processing or assembly like a butterfly throttle valve or a conventional rotary valve. In addition, since the rotary valve can be easily manufactured without requiring high processing accuracy in processing the valve outer peripheral surface and the body inner surface, the manufacturing cost of the rotary valve can be reduced. In addition, the gap between the outer peripheral surface of the valve and the inner diameter surface of the body can prevent malfunction due to thermal deformation, deformation due to assembly, or biting of dust or the like.

  Also, unlike the butterfly throttle valve, the throttle valve and the throttle valve shaft are not configured separately, and if a plurality of valve passage holes are formed in the valve of the rotary valve, control of the plurality of valve passage holes can be achieved. Control with one component is possible. In addition, it is possible to control the flow rate as large as the number of valve through holes with a single rotary valve, and it is possible to provide a rotary valve that is simple in structure and compact.

  As the sealing means, the contact portion shape of the seal is formed in a lip shape, and the support portion of the lip portion formed in the lip shape has elasticity, thereby absorbing variations in individual parts and improving the sealing performance. be able to. By bringing the contact surface of the lip portion into contact with the outer peripheral surface of the valve or the inner surface of the body, the sealing means disposed between the inner diameter of the body and the outer peripheral surface of the valve, A gap between the gaps can be sealed.

  Further, an elastic biasing means as a support portion may be provided at one end portion of the seal body in the sealing means, and the lip portion at the other end portion of the seal body may be in contact with the valve outer peripheral surface or the body inner diameter surface. In this configuration, the sealing performance with respect to the outer peripheral surface of the valve or the inner diameter surface of the body can be improved by using the biasing force of the elastic biasing means.

  By making the contact surface in contact with the valve outer peripheral surface of the lip portion or the inner diameter surface of the body into the corner portion of the lip portion, it is possible to provide a sealing means by line contact, and the operating resistance of the valve can be reduced.

  The non-contact surface side of the body inner diameter portion or the valve outer peripheral surface in the lip portion is arranged toward the high pressure fluid side of the fluid conduit, so that the contact portion of the lip portion is caused by the high pressure side fluid. It is pressed in the contact direction of the inner diameter surface, and the sealing performance of the sealing means can be improved. In addition, when the low pressure fluid side of the fluid line connected to the rotary valve becomes negative pressure, the contact portion of the lip portion is sucked to the valve outer peripheral surface or the body inner surface, thereby improving the sealing performance of the sealing means. Will be able to.

  By using the rotary valve of the present invention as a leading air control valve of a stratified scavenging two-cycle engine, it can be used as a low-cost throttle valve. In addition, the flow of the leading air can be reliably blocked so that the leading air does not leak into the cylinder of the stratified scavenging two-cycle engine at the time of starting or idling. This prevents the leading air from being introduced into the cylinder of the stratified scavenging two-cycle engine during start-up or idling, and the start-up air becomes difficult due to the introduction of the leading air during start-up, or the engine idling speed It is possible to prevent it from becoming difficult to adjust.

  In addition, the rotary valve of the present invention can be freely arranged in the air passage by providing the rotary valve of the present invention as a leading air control valve of the stratified scavenging two-cycle engine in the insulator connected to the intake port of the stratified scavenging two-cycle engine, The space can also be reduced.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The rotary valve of the present invention will be described below using an example in which the rotary valve is provided in the flow path of the leading air of the stratified scavenging two-cycle engine. The rotary valve of the present invention is the leading air of the stratified scavenging two-cycle engine. It is not limited to being provided in the flow path, but can be used as a fluid control valve disposed between the fluid flow paths.

  And the fluid which can be controlled with the rotary valve of this invention can control the flow volume etc. of the fluid called liquid and gas other than air. For this reason, this invention is not limited to the Example demonstrated below, A various change is possible.

  FIG. 1 is a front sectional view of a stratified scavenging two-cycle engine having a rotary valve 35 which is a leading air switching valve according to an embodiment of the present invention. 2-6 has shown the elements on larger scale in the arrangement | positioning site | part of the rotary valve concerning this invention. 2 and 3 show the operating state of the rotary valve according to the first embodiment of the present invention. FIG. 2 shows a state where the rotary valve is closed, and FIG. 3 shows a state where the rotary valve is opened. Is shown.

  FIG. 4 shows a state where the rotary valve according to the second embodiment of the present invention is closed, and FIG. 5 shows a state where the rotary valve according to the third embodiment of the present invention is closed. FIG. 6 shows a state in which the rotary valve according to the fourth embodiment of the present invention is closed.

  As shown in FIG. 1, in the stratified scavenging two-cycle engine 1, a piston 3 is slidably fitted to a cylinder 2 attached to an upper portion of a crankcase 6. One end of a crank 9 rotatably supported in the crank chamber 7 is connected to the crankshaft 8 rotatably attached to the crankcase 6 and the piston 3 is connected via a connecting rod 4. Yes. A spark plug 5 is attached to the top of the cylinder 2.

  An exhaust port 10 opened on the inner wall surface of the cylinder 2 is connected to a muffler 12 via an exhaust passage 11. A scavenging port 16 is opened slightly below the exhaust port 10 on the inner wall surface of the cylinder 2. The scavenging port 16 communicates with the crank chamber 7 through the scavenging flow path 18. Further, the scavenging port 16 communicates with the first leading air flow path 14 communicated with the rotary valve 35 via a piston groove 17 provided on the outer peripheral portion of the piston 3.

  An intake port 15 that opens to the crank chamber 7 is formed in the lower portion of the inner wall surface of the cylinder 2, and the intake port 15 is connected to a second intake passage 31 that communicates with the carburetor 20 via the first intake passage 13. Communicate.

  The first intake passage 13 and the first leading air passage 14 are respectively connected to a second intake passage 31 and a second leading air passage 32 formed in an insulator 30 for heat insulation. The insulator 30 is provided with a rotary valve 35 and a third leading air flow path 33 connected to the rotary valve 35.

  The second intake passage 31 formed in the insulator 30 is connected to the carburetor 20, and the carburetor 20 is connected to a fuel tank and an air cleaner 25 (not shown). Further, the third leading air flow path 33 formed in the insulator 30 is also connected to the air cleaner 25.

  The carburetor 20 is provided with a butterfly-type throttle valve 21 and can control the flow rate of the air-fuel mixture. The butterfly-type throttle valve 21 and the rotary valve 35 are configured such that their throttle amounts are controlled in conjunction by interlocking means such as a link device (not shown).

  Next, the operation of the stratified scavenging two-cycle engine 1 will be described. When the air-fuel mixture compressed in the cylinder chamber C is ignited by the spark plug 5 at the top dead center position of the piston 3 shown in FIG. 1, the air-fuel mixture explodes and pushes the piston 3 downward.

  At this time, the scavenging port 16 and the scavenging flow path 18 are filled with the leading air purified by the air cleaner 25. In the carburetor 20, the crank chamber 7 is filled with an air-fuel mixture in which fuel and air purified by the air cleaner 25 are mixed.

  When the piston 3 descends, the intake port 15 is first closed, and the air-fuel mixture in the crank chamber 7 is compressed. As the piston 3 descends, the exhaust port 10 opens next, and the combustion gas passes through the exhaust passage 11 and is discharged to the outside through the muffler 12. Subsequently, the scavenging port 16 is opened, and the leading air flows into the cylinder chamber C from the scavenging port 16 due to the compressed air-fuel mixture pressure in the crank chamber 7, and the combustion gas remaining in the cylinder chamber C is discharged from the exhaust port 10. Discharge.

  Following the inflow of the leading air into the cylinder chamber C, the air-fuel mixture in the crank chamber 7 flows into the cylinder chamber C, but when the air-fuel mixture flows into the cylinder chamber C, the piston 3 rises and closes the exhaust port 10. It is in the state. Thus, the air-fuel mixture is prevented from being discharged to the outside as it is, the amount of hydrocarbon HC contained in the exhaust gas can be reduced, and fuel waste is also reduced.

  The amount of the air-fuel mixture passing through the vaporizer 20 is controlled by the throttle valve 21, and the amount of the leading air is controlled by the rotary valve 35. Since the throttle amounts of the throttle valve 21 and the rotary valve 35 are controlled in conjunction with each other, the balance between the air-fuel mixture amount and the leading air amount can always be maintained, and combustion can be performed in an optimum state.

  As shown in FIG. 2, the rotary valve 35 includes a valve 36, a body 37, and sealing means 40. A valve passage hole 38 is formed in the valve 36, and a plurality of valve passage holes 38 are formed at predetermined intervals in the axial direction of the valve 36 as necessary. The sealing means 40 has a seal body 43 and a lip portion 41 supported by a support portion 42 formed at one end of the seal body 43.

  The sealing means 40 is composed of a rubber body or the like, and the lip portion 41 is in contact with the outer peripheral surface of the valve 36 by the elastic force of the support portion 42. The seal body 43 is mounted in the inner peripheral surface of the second leading air flow path, and the end opposite to the side where the support portion 42 is formed is the outer peripheral side end of the first leading air flow path 14 formed in the cylinder 2. It is in contact with the vicinity of the part.

  In FIG. 2, the second leading air passage 32 and the third leading air passage 33 constitute a fluid passage in which a rotary valve is disposed in the middle, and the valve 36 and the sealing means 40 constitute a third leading portion. The communication between the air flow path 33 and the second leading air flow path 32 is blocked, and the rotary valve 35 is closed.

  The leading air purified by the air cleaner 25 is blocked into the piston groove 17 and the scavenging flow path 18 by blocking the communication between the third leading air flow path 33 and the second leading air flow path 32 by the valve 36 and the sealing means 40. Supply is cut off. As a result, it is possible to prevent the leading air from being introduced into the cylinder 2 when the stratified scavenging two-cycle engine 1 is started or idling.

  The lip portion 41 of the sealing means 40 is reliably in contact with the outer peripheral surface of the valve 36 by the elastic force of the support portion 42. If the rotary valve 35 is closed when the stratified scavenging two-cycle engine 1 is started or idling, the suction of the crank chamber 7 causes negative pressure on the second leading air passage 32 side, and the inside of the third leading air passage 33 The pressure of the leading air is higher than the pressure of the leading air in the second leading air flow path 32.

  For this reason, the leading air in the third leading air flow path 33 passes through the gap 39 formed between the outer peripheral surface of the valve 36 and the inner surface of the body 37, that is, the non-contact surface side of the lip portion 41, that is, the lip portion 41. Will press the back side that is not in contact with the outer peripheral surface of the valve 36. Further, the negative pressure on the second leading air flow path 32 side attracts the surface side of the lip portion 41 that is in contact with the outer peripheral surface of the valve 36 and strongly presses the lip portion 41 against the outer peripheral surface of the valve 36. Become.

  As a result, the sealing effect by the sealing means 40 is improved, and the leading air can be reliably blocked by the rotary valve 35. Moreover, since the lip portion 41 is elastically supported by the support portion 42 that supports the lip portion 41, the leading air can be blocked more efficiently by the rotary valve 35.

  In the above description, the pressing action on the non-contact surface side of the lip portion 41 by the high pressure leading air in the third leading air passage 33 and the outer periphery of the valve 36 of the lip portion 41 by the negative pressure in the second leading air passage 32. The case where two actions, ie, the pressing action on the contact portion of the lip portion 41 by sucking the surface side in contact with the surface, is described. However, the effect of improving the sealing performance with respect to the lip portion 41 does not act only when the above-described two operations act simultaneously, and the sealing performance with respect to the lip portion 41 even when one action acts on the lip portion 41. The effect | action which improves can be show | played.

  FIG. 3 shows a state in which the rotation of the valve 36 is controlled by an external operation, and the third leading air flow path 33 and the second leading air flow path 32 are in communication with each other by a valve through hole 38 formed in the valve 41, that is, a rotary valve. 35 shows an open state. When the valve 36 rotates, the support portion 42 that elastically supports the lip portion 41 is elastically deformed, and the rotational resistance of the valve 36 can be reduced.

  Further, the lip portion 41 has a corner portion or the like so that the contact portion between the lip portion 41 and the outer peripheral surface of the valve 36 can be brought into contact in a substantially line contact state. The rotational resistance due to contact with the portion 41 can also be reduced.

  FIG. 4 shows a second embodiment according to the present invention. Other than the configuration of the sealing means, other configurations have the same configuration as the first embodiment. For this reason, the description of the member is abbreviate | omitted by using the same member code | symbol as the member code | symbol used in 1st Example.

  As shown in FIG. 4, in the second embodiment, a modification of the support portion is shown, and an elastic piece 44 is formed at one end portion of the seal body 43, and functions as a support portion. The seal body 43 is slidably inserted into the inner diameter surface of the second leading air flow path 32. When the insulator 30 is attached to the cylinder 2 as shown in FIG. 1, the seal body 43 slides to the right in FIG. 4 due to the elasticity of the elastic piece 44, and the lip 41 at the other end of the seal body 43 is connected to the valve 36. Contact the outer peripheral surface.

  At this time, the elastic piece 44 as a support portion also has a function of sealing the outer peripheral portion of the first leading air flow path 14 formed in the cylinder 2, and the outer peripheral surface of the valve 36 and the body from the third leading air flow path 33. The space between the flow path passing through the gap formed between the 37 inner diameter surfaces and the second leading air flow path 32 can be reliably sealed.

  When the valve 36 is rotated by external control, the seal main body 43 slides in a direction in which the elastic piece 44 is bent, and the rotational resistance of the valve 36 by the sealing means 40 can be reduced. 4 shows an example in which the lip portion directly supported by the support portion as in the first embodiment is not formed on the sealing means 40 that contacts the outer peripheral surface of the valve 36, but the valve of the seal main body 43 is shown. A lip portion elastically supported by a support portion as shown in the first embodiment may be formed at an end portion that contacts the 36 outer peripheral surface.

  When the lip portion directly designated by the support portion is formed at the end portion of the seal body 43 that contacts the outer peripheral surface of the valve 36, the valve 36 is caused by a synergistic effect due to elastic deformation of the lip portion and the elastic piece 44 when the valve 36 rotates. Rotational resistance can be reduced. Further, in the case where the lip portion directly supported by the support portion is formed or not formed, the contact between the sealing means 40 and the valve 36 of the second embodiment can be a surface contact state. It is desirable to keep in contact.

  Further, in the case where the lip portion directly supported by the support portion is formed or not formed, in the sealing means 40 of the second embodiment, the lip portion 41 is not contacted by the high pressure leading air in the third leading air flow path 33. The pressing action acting on the surface side and the suction action on the lip portion 41 by sucking the surface side in contact with the outer peripheral surface of the valve 36 of the lip portion 41 due to the negative pressure in the second leading air flow path 32 are: Similar to the first embodiment, the second embodiment can also be achieved.

  Further, the lip portion has a corner or the like so that the contact portion between the outer peripheral surface of the valve 36 of the seal body 43 and the outer peripheral surface of the valve 36 can be brought into contact with each other in a substantially line contact state. You can also. At this time, the rotational resistance due to the contact between the lip portion and the valve 36 during the rotation of the rotary valve 35 can be further reduced.

  FIG. 5 shows a third embodiment according to the present invention. Except for the configuration in which the sealing means is arranged on the outer peripheral portion of the valve 36, the other configurations have the same configurations as the first embodiment. For this reason, the description of the member is abbreviate | omitted by using the same member code | symbol as the member code | symbol used in 1st Example.

  As shown in FIG. 5, in the third embodiment, the sealing means 40 is formed on the outer peripheral surface of the valve 36. When the valve passage hole 38 is in the position shown in FIG. 5 and the second leading air passage 32 and the third leading air passage 33 are not in communication with each other, the sealing means 40 and the third leading air passage 33 A seal body 43 and a lip portion 41 are formed in a configuration in which the gap 39 is sealed.

  Also in the sealing means 40 of the third embodiment, the pressing action acting on the non-contact surface side of the lip portion 41 by the high pressure leading air in the third leading air flow path 33 and the negative pressure in the second leading air flow path 32. The suction action to the lip portion 41 by sucking the surface side of the lip portion 41 that is in contact with the inner surface of the body 37 can be achieved in the third embodiment as well as in the first embodiment. it can.

  The seal body 43 is also rotated by the rotation of the valve 36, and the lip portion 41 is rotated while being in contact with the inner diameter surface of the body 37. Since the lip portion 41 is elastically supported by the support portion 42, the rotational resistance from the lip portion 41 can be reduced when the valve 36 rotates.

  Further, the lip portion 41 has a corner portion or the like so that the contact portion between the lip portion 41 and the inner surface of the body 37 can be brought into a substantially line contact state. The rotational resistance due to contact between the portion 41 and the inner surface of the body 37 can also be reduced.

  FIG. 6 shows a fourth embodiment according to the present invention. Except for the configuration in which the sealing means is mounted in the third leading air flow path 33 and the lip portion 41 is formed inward, the other configurations are as follows. A configuration similar to that of the first embodiment is provided. For this reason, the description of the member is abbreviate | omitted by using the same member code | symbol as the member code | symbol used in 1st Example.

  As shown in FIG. 6, in the fourth embodiment, the sealing means 40 is mounted in the third leading air flow path 33 which is a connection flow path with the air cleaner 25 shown in FIG. Contrary to the case of the third embodiment, it is formed inward. For this reason, the non-contact surface side of the lip portion 41 can be pressed from the third leading air passage 33 by the leading air having a pressure higher than that of the leading air in the second leading air passage 32, and the lip portion 41 and the valve The sealing property with the outer peripheral surface of 36 can be improved.

  In addition, when the stratified scavenging two-cycle engine 1 is started, the second leading air flow path 32 becomes negative pressure during idling, so that the surface side of the lip portion 41 that is in contact with the outer peripheral surface of the valve 36 is sucked. Thus, the pressing force of the lip 41 to the outer surface of the valve 36 can be increased, and the sealing performance of the sealing means 40 can be improved.

  When the valve 36 rotates, the rotational resistance of the valve 36 caused by the contact with the lip portion 41 can be reduced by the elastic force of the support portion 42. Further, the lip portion 41 has a corner portion or the like so that the contact portion between the lip portion 41 and the outer peripheral surface of the valve 36 can be brought into contact in a substantially line contact state. The rotational resistance due to contact between the portion 41 and the outer peripheral surface of the valve 36 can also be reduced.

  In the fourth embodiment, an elastic piece may be formed on the side of the air cleaner 25 of the seal body 43 as in the second embodiment. Furthermore, the structure of the sealing means of the first embodiment to the third embodiment may be added to the structure of the sealing means of the fourth embodiment.

  The present invention relates to a rotary valve that can be arranged in a fluid flow path. However, the technical idea of the present invention can be applied to an apparatus that can use a rotary valve.

It is a schematic front sectional view showing an overall view of the present invention. (Example) It is a schematic sectional drawing which shows the closed state of a rotary valve. Example 1 It is a schematic sectional drawing which shows the open / close state of a rotary valve. Example 1 It is a schematic sectional drawing which shows the closed state of a rotary valve. (Example 2) It is a schematic sectional drawing which shows the closed state of a rotary valve. (Example 3) It is a schematic sectional drawing which shows the closed state of a rotary valve. Example 4 It is a schematic front sectional drawing which shows the general view of a prior art example. (Conventional example 1) It is a schematic front sectional view showing an overall view of another conventional example. (Conventional example 2)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Layered scavenging two-cycle engine 2 Cylinder 3 Piston 5 Spark plug 6 Crankcase 7 Crank chamber 8 Crankshaft 10 Exhaust port 13 First intake passage 14 First leading air passage 15 Intake port 16 Scavenging port 17 Piston groove 18 Scavenging airflow Path 20 Vaporizer 21 Throttle valve 30 Insulator 32 Second leading air flow path 33 Third leading air flow path 35 Rotary valve 36 Valve 37 Body 38 Valve passage hole 39 Clearance 40 Sealing means 41 Lip part 42 Support part 43 Seal body 44 Elasticity Piece 50 Cylinder 51 Piston 53 Crank chamber 54 Exhaust port 57 Intake port 58 Scavenging port 59 Scavenging passage 60 Vaporizer 61 Throttle valve 65 Leading air passage 66 Air control valve 67 Insulator 70 Vaporizer 71 Air control valve 73 Throttle valve 74 Throttle valve 76 Cylinder 77 Piston 7 Exhaust port 81 scavenging ports 82 transfer passages 83 the air passage 84 check valve 85 intake port 86 check valve 87 crankcase A~C cylinder chamber

Claims (4)

In a rotary valve configured as a leading air control valve for a stratified scavenging two-cycle engine,
The rotary valve has a valve and a body;
A gap is formed between the inner diameter of the body and the outer peripheral surface of the valve,
Seal means for sealing the gap is disposed between the body inner diameter portion and the valve outer peripheral surface,
The sealing means has a lip portion that is elastically supported, and is provided on the outer peripheral surface of the valve or the inner diameter portion of the body,
The rotary valve according to claim 1, wherein the lip portion is pressed and urged toward the body inner diameter portion or the valve outer peripheral surface with which the lip portion contacts by high pressure air acting on the rotary valve. The rotary valve according to claim 1 , wherein the rotary valve is provided in an insulator connected to an intake port of the stratified scavenging two-cycle engine. Wherein the lip portion is, claim 1 or 2 rotary valve, wherein the contact with the valve outer circumferential surface. Wherein the lip portion is, claim 1 or 2 rotary valve, wherein the contact with the body bore.

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