JP2005048722A - Lubrication structure of vertical engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the performance of a non-return valve and to secure the accurate travel of a valve body. <P>SOLUTION: In this lubrication structure of a vertical engine having a vertical crankshaft, a valve system chamber is communicated with a crank chamber through an air vent passage 80, and the non-return valve 100 permitting air flow only from the crank chamber to the valve system chamber is interposed in the air vent passage. Contact surfaces 12a, 31a between a cylinder part 12 communicated with the crank chamber and a cylinder head 31 are sealed with a gasket 32. The air vent passage pierces through the gasket. In the non-check valve, a valve storing part 101 is formed in the contact surface of the cylinder part, a valve seat 104 is formed at the bottom of the valve storing part, a stopper 106 is formed in the midway of the valve storing part, a lid 111 put in through an opening of the valve storing part is abutted on the stopper, and the valve body 121 is put in between the lid and the valve seat. A pressing part 135 having elasticity is provided in the periphery of the air vent passage provided in the gasket, whereby the lid is resiliently pressed to the stopper side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for improving a lubricating structure in which lubricating oil is forcibly supplied to a valve operating chamber of a so-called vertical engine of a type in which a crankshaft is oriented substantially vertically (vertically).

  In the vertical engine, a lubricating system in which lubricating oil is forcibly supplied from the oil pan to the valve operating chamber and the lubricating oil remaining in the valve operating chamber is returned to the oil pan is frequently used. The lubricating oil remaining in the valve operating chamber returns to the oil pan through an oil return path having a flow gradient. The remaining lubricating oil is preferably discharged as much as possible.

  However, the valve chamber of the vertical engine is at a relatively low position obliquely above the oil pan provided at the bottom of the crankcase. For this reason, it is not easy to set a large flow gradient in the oil return path.

In response to such a problem, in the vertical engine lubrication structure, it is possible to promote the discharge of the lubricating oil remaining in the valve chamber even if the flow gradient of the oil return path for returning the lubricant from the valve chamber to the oil pan is small. Such a technique is known (for example, see Patent Document 1).
JP 61-98909 A

An outline of a lubricating structure of a conventional vertical engine according to Patent Document 1 will be described with reference to FIG.
8 (a) and 8 (b) are schematic views of a conventional vertical engine lubrication structure, which is a reprint of the main part of FIGS. 1 and 2 of Patent Document 1. FIG. However, the sign has been changed.

As shown in FIG. 2A, the conventional vertical engine 200 has a lubricating structure in which a lubricating oil is supplied from an oil pan 202 provided at the bottom of the crankcase 201 via an oil supply path 204 by an oil supply pump 203. The lubricating oil remaining in the valve operating chamber 205 is returned to the oil pan 202 through the oil return passage 206, and further, the valve operating chamber 205 is vented into the crankcase 201 through the air passage 207. The communication was made possible.
The ventilation path 207 includes a check valve 210 that allows only ventilation from the crankcase 201 to the valve operating chamber 205.

  The check valve 210 includes a flat valve seat fixing plate 212 having a valve seat 211 in the center and a valve holder at a position away from the valve seat fixing plate 212 by a certain distance, as shown in FIG. 213 and a flat valve body 214 interposed between the valve seat 211 and the valve holder 213.

The valve seat 211 is composed of an annular projecting portion projecting on a surface facing the valve body 214. The valve holder 213 includes an annular protrusion 215 that protrudes from a surface facing the valve body 214. Reference numerals 216 and 217 denote communication holes.
The distance from the protruding surface of the valve seat 211 to the protrusion 215 is L21. This distance L21 defines the amount of movement (stroke) by which the valve body 214 moves.

  The pressure in the crankcase 201 varies according to the reciprocation of the piston 221. Only when the pressure in the crankcase 201 increases, the check valve 210 opens. Due to the pressure difference between the crankcase 201 and the valve operating chamber 205, it is possible to promote the discharge of the lubricating oil remaining in the valve operating chamber 205.

By the way, according to the reciprocating motion of the piston 221, the pressure in the crankcase 201 fluctuates frequently. The check valve 210 repeats opening and closing according to the pressure fluctuation. That is, the valve body 214 frequently and vigorously hits the valve seat 211 and the protrusion 215 of the valve holder 213.
Preventing deformation and misalignment of the valve seat fixing plate 212 and the valve holder 213 due to a frequently generated impact force and suppressing wear of the protrusions 215 ensure the performance of the check valve 210 and are durable. It is important to improve sex.

  Further, since the check valve 210 is formed by stacking a thin plate-shaped valve seat fixing plate 212 and a valve holder 213, the distance L21 from the protruding surface of the valve seat 211 to the protrusion 215 is accurately set. Is not easy. Increasing the accuracy of the distance L21 is important in securing an accurate amount of movement of the valve body 214. A complicated configuration to increase accuracy is not a good idea because it increases man-hours.

  It is an object of the present invention to provide a technique capable of ensuring the performance of a check valve and enhancing the durability with a simple configuration and ensuring an accurate movement amount of a valve body in the check valve. And

According to the first aspect of the present invention, a cylinder portion is provided on the side of a crankcase that houses a substantially vertical crankshaft, a cylinder head is overlapped and fixed on the side of the cylinder portion, and a gasket is interposed on the mating surface. A vertical engine with a valve chamber in the cylinder head, and an oil pan at the bottom of the crankcase. The lubricating oil accumulated in the oil pan is valved through an oil supply path by an oil supply pump. The lubricating oil remaining in the valve chamber is returned to the oil pan through the oil return passage, and the valve chamber is communicated with the crankcase through the vent passage so as to be ventilated. In the lubrication structure of the vertical engine, a check valve that allows only ventilation from the crankcase to the valve operating chamber is interposed on the road,
The ventilation path is a ventilation hole formed so as to communicate from the inside of the crankcase to the valve operating chamber through the cylinder part, the gasket and the cylinder head.
The non-return valve is a part formed in the cylinder part of the air passage, and forms a valve storage part in the part opened toward the mating surface, and forms a valve seat at the bottom of the valve storage part, A stopper is formed at a position that enters a certain distance from the opening, and a lid with a vent hole that is inserted from the opening side of the valve housing is placed at a position that contacts the stopper, and moves between the lid with a vent hole and the valve seat. It is a configuration with a valve body that opens and closes by
A pressing part having elasticity is provided around a ventilation path (venting hole) formed in the gasket, and the pressing part is configured to repel the lid with the vent hole toward the stopper.

In the invention according to claim 1, a valve housing portion is formed in a portion formed in the highly rigid cylinder portion of the ventilation path and facing the mating surface. Since the valve seat is formed on the bottom, even if the valve body frequently and vigorously hits the valve seat, the valve seat can be prevented from being deformed or displaced.
In addition, an elastic pressing part is provided around a ventilation path (venting hole) formed in the gasket for sealing the mating surfaces, and the pressing part is configured to repel the lid with the vent hole toward the stopper. Therefore, the impact force that the valve body hits the lid can be reduced by the elasticity of the pressing portion. For this reason, even if the valve body frequently and vigorously hits the lid, it is possible to prevent deformation and displacement of the lid and to suppress wear of the contact surface of the valve body on the lid. Therefore, with a simple configuration, the performance of the check valve can be ensured and the durability can be enhanced.

  Furthermore, a stopper is formed at a position that enters the valve housing part at a certain distance from the opening, a lid with a vent hole that is inserted from the opening side of the valve housing part is disposed at a position that contacts the stopper, and the mating surface is sealed. Since an elastic pressing part is provided around the air passage formed in the gasket and the lid is repelled toward the stopper by this pressing part, the lid is brought into contact with the stopper by the elasticity of the pressing part. It can be reliably and accurately arranged. For this reason, the accuracy of the distance from the valve seat to the lid can be increased only by increasing the accuracy of the distance from the valve seat to the stopper. As a result, an accurate movement amount (stroke) of the valve body can be ensured. Therefore, with a simple configuration, the performance of the check valve can be ensured and the durability can be enhanced.

  In this way, by maintaining the opening / closing performance of the check valve, it is possible to maintain an appropriate pressure difference between the crankcase and the valve operating chamber. As a result, the air permeability from the crankcase to the valve operating chamber can be maintained. Therefore, the discharge of the lubricating oil remaining in the valve chamber can be further promoted by the pressure difference between the crankcase and the valve chamber.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view (No. 1) of a vertical engine according to the present invention as seen from the side, and shows a cross section so that an oil supply path 60 and an oil return path 70 of a lubricating structure mainly appear.

  The engine 10 is an OHV type (overhead valve type) single-cylinder vertical engine in which a crankshaft 21 is housed in a crankcase 11 in a substantially vertical direction (vertically placed).

  The crankcase 11 is a box-shaped case in which the cylinder portion 12 is integrally formed and the lower portion is opened. The lower open end is closed by a detachable bottom plate 13, and a crankshaft 21 oriented substantially vertically in the internal space. The power take-out portion (PTO) 22 of the crankshaft 21 protrudes downward from the bottom plate 13 and the upper portion 23 of the crankshaft 21 protrudes upward from the upper plate 14 while being housed and rotatably supported.

  The crankshaft 21 has a piston 25 connected to a longitudinal center via a lateral connecting rod 24, and a starter gear 26 and a cooling fan 27 connected to an upper portion 23. The cylinder part 12 is a member having a cylinder in which the piston 25 reciprocates. The starter gear 26 is a member driven by a starter motor (not shown).

  Such an engine 10 includes a cylinder portion 12 beside the crankcase 11, a cylinder head 31 is overlapped on the side of the cylinder portion 12 and fixed with bolts, and a gasket 32 is interposed between the mating surfaces to seal the cylinder head 31. The cylinder head 31 is provided with a valve operating chamber 33, and the oil pan 51 is provided at the bottom of the crankcase 11. The oil pan 51 is a member that is formed integrally with the bottom plate 13 and stores the lubricating oil Oi.

  A space formed between the tip of the cylinder portion 12 and the cylinder head 31 is a combustion chamber 34. Further, the engine 10 bolts the head cover 35 to the tip of the cylinder head 31, so that a space surrounded by the cylinder head 31 and the head cover 35 becomes a valve operating chamber 33, and the valve operating mechanism 40 is arranged in the valve operating chamber 33. did.

The valve operating mechanism 40 includes an intake valve rocker arm 41 and an intake valve 42, an exhaust valve rocker arm 43 and an exhaust valve 44 as main components.
Further, the crankcase 11 houses a camshaft 46 that is parallel to the crankshaft 21. When the driven gear 47 of the camshaft 46 is driven by the drive gear 45 of the crankshaft 21, the two cams 48, 48 formed with the camshaft 46 are connected to the intake valve rocker arm 41 via a push rod (not shown). In addition, the exhaust valve rocker arm 43 can be driven. As a result, the intake valve 42 can be opened / closed by the intake valve rocker arm 41 and the exhaust valve 44 can be opened / closed by the exhaust valve rocker arm 43.

  The lubricating structure of the engine 10 is such that the lubricating oil Oi stored in the oil pan 51 is forcibly supplied to the periphery of the camshaft 46, the valve operating chamber 33, and the like through the oil supply path 60 by the oil supply pump 52. This is a forced lubrication system configuration in which excess lubricating oil remaining in 33 is returned to the oil pan 51 via the oil return path 70. The valve operating mechanism 40 can be lubricated by the lubricating oil supplied to the valve operating chamber 33.

More specifically, the oil pan 51 is provided with an oil supply pump 52 such as a trochoid pump. By connecting the input shaft 53 of the oil supply pump 52 to the camshaft 46, the oil supply pump 52 can be driven by the crankshaft 21 via the camshaft 46.
The oil supply pump 52 housed in the oil pan 51 sucks the lubricating oil Oi accumulated in the oil pan 51 and supplies it to the periphery of the camshaft 46 and the valve operating chamber 33 through the oil supply path 60. .

  The oil supply path 60 has a first oil supply path 61 formed in the oil pan 51 so as to be connected to a discharge port of the oil supply pump 52 and a first oil supply path 61 formed in the crankcase 11 so as to communicate with the first oil supply path 61. The second oil supply path 62 includes a second oil supply path 62 and a third oil supply path 63 formed in the cylinder head 31 so as to communicate with the valve operating chamber 33.

The oil return path 70 is formed in the lower part of the cylinder portion 12 so as to communicate with the first oil return path 71 formed in the lower part of the cylinder head 31 so as to communicate with the bottom of the valve operating chamber 33 and the first oil return path 71. The second oil return path 72 is formed, and the third oil return path 73 is formed in the oil pan 51 so as to communicate with the second oil return path 72.
The first and second oil return paths 71 and 72 have a slight flow gradient so that the lubricating oil flows toward the oil pan 51. The tip of the third oil return path 73 extends to a position lower than the oil level OL of the lubricating oil Oi stored in the oil pan 51.

FIG. 2 is a cross-sectional view of the vertical engine according to the present invention as viewed from the side (part 2). A part of the oil supply passage 60 is omitted and shown in imaginary lines, and a ventilation passage 80 having a lubricating structure is mainly used. As shown in FIG.
As shown in FIG. 2, in the lubrication structure of the engine 10, the valve chamber 33 is communicated with the inside of the crankcase 11 through the air passage 80 so as to be able to vent, and the check valve 100 is interposed in the air passage 80. It is characterized by that.

The ventilation path 80 is a ventilation hole formed so as to communicate from the inside of the crankcase 11 (that is, the crank chamber 15) to the valve operating chamber 33 through the cylinder portion 12, the gasket 32 and the cylinder head 31.
Specifically, the air passage 80 is formed in the gasket 32 so as to communicate with the first air passage 81 formed in the upper portion of the cylinder portion 12 so as to communicate with the crank chamber 15 and the first air passage 81. The air passage 82 includes a third air passage 83 formed in the cylinder head 31 so as to communicate with the second air passage 82 and the valve operating chamber 33.
The check valve 100 is a so-called one-way valve that allows only ventilation from the crankcase 11 to the valve operating chamber 33 and prevents ventilation in the opposite direction, and is also referred to as a check valve.

3 is a cross-sectional view taken along line 3-3 of FIG. However, only the side surface of the gasket 32 is shown.
The gasket 32 includes a central cylinder hole 91, four bolt insertion holes 92 around the cylinder hole 91 (... indicates a plurality, the same applies hereinafter), and an upper right of the cylinder hole 91. The oil supply passage hole 93, the lower right oil return passage hole 94 of the cylinder hole 91, and the upper left second air passage 82 of the cylinder hole 91 are arranged in the thickness direction of the gasket 32, that is, the front-back direction. It is made to penetrate.

  The cylinder hole 91 is a hole communicating with the cylinder of the cylinder portion 12 shown in FIG. The bolt insertion holes 92... Are holes through which bolts for fixing the cylinder portion 12 and the cylinder head 31 shown in FIG. The oil supply passage hole 93 is a communication hole communicating with the oil supply passage 60 shown in FIG. The oil return path hole 94 is a communication hole communicating with the oil return path 70 shown in FIG. As described above, the second air passage 82 is a communication hole communicating with the first and third air passages 81 and 83 shown in FIG.

  95 is a bead around the cylinder hole 91, 96 is a bead around the oil supply passage hole 93, 97 is a bead around the oil return passage hole 94, and 98 is a bead around the second air passage 82. It is. These beads 95 to 98 are provided on both the front and back surfaces of the gasket 32 in order to improve the sealing performance of the sealing portion (sealing portion).

  FIG. 4 is a cross-sectional view of the air passage and the check valve according to the present invention, corresponding to FIG. FIG. 5 is an exploded view of the check valve according to the present invention, corresponding to FIG. FIG. 6 is an exploded perspective view of the check valve according to the present invention.

  As shown in FIG. 4, the flange 12 a of the cylinder portion 12 is configured to be fixed to the flange 31 a of the cylinder head 31 with a bolt 37. As described above, the cylinder head 31 is overlaid on the cylinder portion 12, and the mating portion can be sealed by sandwiching the gasket 32 between the mating surfaces 12b and 31b, that is, the flange surfaces 12b and 31b.

  As shown in FIGS. 4 to 6, the check valve 100 is formed on the valve housing portion 101 formed on the mating portion of the cylinder portion 12 (portion on the mating surface 12 b side) and on the bottom portion 102 of the valve housing portion 101. The valve seat 104, a plurality of (for example, three or more) stoppers 106 formed on the side wall 105 of the valve storage portion 101, the lid 111 that closes the opening of the valve storage portion 101, the lid 111, and the valve seat 104 And a valve body 121 that opens and closes by moving between them. The valve body 121 is a flat flat disk having a constant thickness t1.

  The valve storage portion 101 is a portion 81 formed in the cylinder portion 12 in the ventilation passage 80 (that is, the first ventilation passage 81), and is formed in a bottomed cylindrical shape that is open to the mating surface 12b. This is a storage hole. As shown in FIG. 5, the hole diameter D <b> 1 of the valve storage portion 101 is larger than the diameter D <b> 2 of the first ventilation path 81.

  The bottom portion 102 of the valve storage portion 101 opens so as to communicate with the first air passage 81, and the edge of the opening is formed in an annular convex shape protruding toward the mating surface 12b, and the tip surface of this convex portion Is a flat seat surface 103, and the convex portion is the valve seat 104.

The plurality of stoppers 106 are convex portions formed in the valve storage portion 101 from the opening 101a on the side of the mating surface 12b, that is, at a position entering the fixed distance L1 from the mating surface 12b. All the stopper surfaces 107... Of each of the stoppers 106... Are at a position where they enter the fixed distance L1 from the mating surface 12b. This distance L1 (stopper entering distance L1) is slightly larger than the plate thickness t2 of the lid 111.
More specifically, as shown in FIG. 5, the plurality of stoppers 106 are convex portions that protrude from the side wall 105 toward the center CL of the valve storage portion 101 by a fixed protrusion amount X1, -An elongated member extending from the bottom 102 to the bottom 102.

The distance from the stopper surface 107 to the seat surface 103 of the valve seat 104 is L2. The stopper surface 107... And the seat surface 103 of the valve seat 104 are parallel to the mating surface 12b.

The plurality of stoppers 106 also serve as a guide member that guides the valve body 121 when the valve body 121 moves between the lid 111 and the valve seat 104. In addition, as shown in FIG. 6, the gap 108 between the adjacent stoppers 106 and 106 serves as a ventilation path that vents when the valve body 121 is opened. Hereinafter, the gap 108 is referred to as a first valve opening ventilation path 108.

The lid 111 is a flat disk having a constant thickness, and is a lid with a vent hole in which a vent hole 112 is opened at the center. Such a lid 111 is inserted from the side of the opening 101 a of the valve housing 101 and is disposed at a position where it hits the stopper 106.
Further, the lid 111 is formed with a plurality of (for example, three) valve body stoppers 113... Projecting toward the valve body 121 side. As shown in FIG. 5, the protrusion amounts of the valve body stoppers 113 are all X2. As shown in FIG. 6, the gap 114 between the adjacent valve body stoppers 113, 113 serves as a ventilation path that vents when the valve body 121 is opened. Hereinafter, the gap 114 is referred to as a second valve opening air passage 114.

  As shown in FIG. 4, when the lid 111 is in contact with the stopper surface 107 ..., the distance from the tip of the valve body stopper 113 ... to the seat surface 103 is L3, and the valve body stopper 113 ... The distance from the tip of the valve body 121 to the valve body 121 is L4. This distance L4 corresponds to the movement amount (stroke) of the valve body 121.

  Here, the “gasket 32” is a flat seal member used for sealing a stationary joint portion such as the mating surfaces 12b and 31b, and is also called a stationary seal. The gasket 32 of the present invention is a three-layer composite sealing member in which both front and back surfaces of a core material 131 are sandwiched (wrapped) between thin sheet metal skin materials 132 and 133, and is called a metal gasket. Yes. An example of the thin plate-like metal material is a stainless steel plate having a thickness of about 0.2 mm.

  In such a gasket 32, the diameter D3 of the second air passage 82 (vent hole) is made smaller than the outer diameter D4 of the lid 111, and an elastic pressing portion 135 is provided around the second air passage 82 having a small diameter. , And the pressing part 135 is configured to repel the lid 111 with a vent hole toward the stoppers 106.

  More specifically, the diameter D3 of the second air passage 82 penetrating the skin materials 132 and 133 is smaller than the outer diameter D4 of the lid 111 and slightly larger than the diameter D5 of the vent hole 112 of the lid 111. On the other hand, the core member 131 is formed with a vent hole 134 that is concentric with the second vent path 82. The diameter D6 of the air hole 134 is larger than the diameter D3 of the second air passage 82 and slightly smaller than the outer diameter D2 of the lid 111.

Of the front and back skin materials 132 and 133, at least the skin material 132 on the lid 111 side is formed by integrally forming the pressing portion 135. The pressing portion 135 is a convex portion that protrudes toward the lid 111 by a protruding amount X3, and is formed at the edge of the second air passage 82 and protrudes most, and a conical portion around the pressing end portion 136. It is the part which formed the elastic part 137 of a shape (taper view sectional shape) integrally. The pressing end portion 136 is a flat portion parallel to the skin material 132.
The protrusion amount X3 of the pressing portion 135 is set larger than the remaining dimension L5 (see FIG. 4) obtained by subtracting the plate thickness t2 of the lid 111 from the stopper insertion distance L1. For this reason, the pressing part 135 has elasticity by the dimension L5 and can press the lid 111.

Since the elastic portion 13 7 has a conical shape made of an extremely thin metal plate, when the pressing portion 135 is displaced in the thickness direction of the gasket 32, the pressing portion 135 is repelled in the thickness direction to restore the original position. It plays the role of a resilient member.
The outer diameter D <b> 7 of the pressing end 136 is about twice as large as the diameter D <b> 3 of the second air passage 82. The outer diameter D8 of the elastic portion 133 is about twice as large as the outer diameter D7 of the pressing end portion 136, and is slightly smaller than the diameter D6 of the vent hole 134 of the core member 131.

  Next, the operation of the check valve 100 configured as described above will be described with reference to FIGS. FIGS. 7A and 7B are operation diagrams of the check valve according to the present invention.

  In FIG. 2, when the piston 25 moves backward from the combustion chamber 34 side (when moved in the direction of arrow A1 in FIG. 2), the volume of the crank chamber 15 decreases, so that the air pressure increases. For this reason, the air pressure in the crank chamber 15 exceeds the air pressure in the valve operating chamber 33. Therefore, as shown in FIG. 7A, the air pressure in the first air passage 81 exceeds the air pressure in the third air passage 83. The valve element 121 moves away from the valve seat 104 by the air pressure of the first air passage 81 that has exceeded, and moves until it contacts the valve element stoppers 113. That is, the check valve 100 is opened.

  As a result, the air in the crank chamber 15 (see FIG. 2) flows from the first ventilation path 81 → the first valve opening ventilation path 108 → the second valve opening ventilation path 114 → the ventilation hole 112 → the second ventilation path 82 → third. It flows to the valve operating chamber 33 (see FIG. 2) through the passage of the air passage 83. The high-pressure air that has flowed into the valve operating chamber 33 pushes the lubricating oil remaining in the valve operating chamber 33 to the oil pan 51 through the oil return path 70. Thus, the discharge of the lubricating oil remaining in the valve operating chamber 33 can be promoted by the high-pressure air.

  Thereafter, in FIG. 2, when the piston 25 moves forward to the combustion chamber 34 side (when moved in the direction of arrow A2 in FIG. 2), the volume of the crank chamber 15 increases, so the air pressure decreases. For this reason, the air pressure in the crank chamber 15 is lower than the air pressure in the valve operating chamber 33. Therefore, as shown in FIG. 7B, the air pressure in the third air passage 83 exceeds the air pressure in the first air passage 81. The valve body 121 moves away from the valve body stopper 113... By the air pressure of the third air passage 83 that has exceeded, and moves until it contacts the valve seat 104. That is, the check valve 100 is closed. As a result, the high pressure state of the valve operating chamber 33 (see FIG. 2) is maintained.

  Thus, the pressure in the crankcase 11 (crank chamber 15) varies according to the reciprocation of the piston 25. Only when the pressure in the crankcase 11 increases, the check valve 100 opens. Due to the pressure difference between the crankcase 11 and the valve operating chamber 33, it is possible to promote the discharge of the lubricating oil remaining in the valve operating chamber 33.

  By the way, as shown in FIG. 4, the valve storage part 101 is formed in the part formed in the highly rigid cylinder part 12 of the ventilation path 80 and facing the mating surface 12b. Since the valve seat 104 is formed on the bottom portion 102 of the valve storage portion 101, even if the valve body 121 hits the valve seat 104 frequently and vigorously, deformation and displacement of the valve seat 104 can be prevented.

  In addition, since a pressing portion 135 having elasticity is provided around the second ventilation path 82 formed in the gasket 32 and the lid 111 is repelled toward the stopper 106 by the pressing portion 135, the lid 111 The impact force applied to the valve body 121 can be reduced by the elasticity of the pressing portion 135. For this reason, even if the valve element 121 hits the lid 111 frequently and vigorously, the deformation and displacement of the lid 111 can be prevented and the wear of the valve element contact surface (that is, the valve element stopper 113...) In the lid 111 can be prevented. Can be suppressed. Therefore, with a simple configuration, the performance of the check valve 100 can be ensured and the durability can be enhanced.

  Furthermore, a stopper 106... Is formed at a position that enters the valve housing 101 by a certain distance L1 from the opening 101a, and a lid 111 that is inserted from the opening 101a side of the valve housing 101 hits the stopper 106. Further, a pressing portion 135 having elasticity is provided around the second ventilation path 82, and the lid 111 is configured to be repelled toward the stopper 106 by the pressing portion 135. Due to the elasticity of the portion 135, the lid 111 can be reliably and accurately arranged at a position where it hits the stopper 106. Therefore, the accuracy of the distance L2 from the valve seat 104 to the lid 111 can be increased only by increasing the accuracy of the distance L2 from the valve seat 104 to the stopper 106. As a result, an accurate movement amount (stroke) of the valve body 121 can be ensured. Therefore, with a simple configuration, the performance of the check valve 100 can be ensured and the durability can be enhanced.

  Thus, by maintaining the opening / closing performance of the check valve 100, an appropriate pressure difference between the crankcase 11 and the valve operating chamber 33 can be maintained as shown in FIG. As a result, the air permeability from the crankcase 11 to the valve operating chamber 33 can be maintained. Therefore, the discharge of the lubricating oil remaining in the valve operating chamber 33 can be further promoted by the pressure difference between the crankcase 11 and the valve operating chamber 33.

In the embodiment, the vertical engine 10 is applied to the OHC type (overhead camshaft type) in the embodiment, but may be applied to the OHV type (overhead valve type).
In addition, the gasket 32 has a three-layer structure of the core member 131 and the skin members 132 and 133 on both sides thereof, but is not limited thereto. For example, the core member 131 and one of the front and back skin members 132 are provided. Or a single-layer structure including only the core member 131 may be used.

  The vertical engine 10 of the present invention is suitable for a working machine such as a snowplow.

It is sectional drawing (the 1) which looked at the vertical engine which concerns on this invention from the side. It is sectional drawing (the 2) which looked at the vertical engine which concerns on this invention from the side. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is sectional drawing of the ventilation path and check valve which concern on this invention. It is an exploded view of the check valve concerning the present invention. 1 is an exploded perspective view of a check valve according to the present invention. It is an action figure of a check valve concerning the present invention. It is a schematic diagram of the lubrication structure of the conventional vertical engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vertical engine, 11 ... Crankcase, 12 ... Cylinder part, 12b ... Matching surface, 15 ... In a crankcase (crank chamber), 21 ... Crankshaft, 31 ... Cylinder head, 32 ... Gasket, 33 ... Valve-operating chamber, DESCRIPTION OF SYMBOLS 51 ... Oil pan, 52 ... Oil supply pump, 60 ... Oil supply path, 70 ... Oil return path, 80 ... Ventilation path, 82 ... Gasket ventilation path (2nd ventilation path), 100 ... Check valve, 101 ... Valve Storage part, 101a ... Opening of valve storage part, 102 ... Bottom of valve storage part, 104 ... Valve seat, 106 ... Stopper, 111 ... Lid, 112 ... Vent, 121 ... Valve body, 135 ... Pressing part, Oi ... Lubrication Oil, L1... A certain distance from the opening of the valve housing (distance of stopper).

Claims (1)

A cylinder part is provided on the side of a crankcase that houses a substantially vertical crankshaft. The cylinder head is overlapped and fixed to the side of the cylinder part, and the mating surface is sealed with a gasket interposed therebetween. A vertical engine provided with the valve operating chamber, wherein an oil pan is provided at the bottom of the crankcase, and lubricating oil stored in the oil pan is supplied to the valve operating chamber via an oil supply path by an oil supply pump. The lubricating oil remaining in the valve chamber is returned to the oil pan through an oil return path, and the valve chamber is communicated with the inside of the crankcase through the vent path so that the valve chamber can be vented. In the lubricating structure of the vertical engine, which includes a check valve that allows only ventilation from the crankcase to the valve operating chamber,
The vent path is a vent hole formed so as to communicate from the inside of the crankcase to the valve operating chamber through the cylinder portion, the gasket and the cylinder head,
The check valve has a valve housing portion formed in a portion of the air passage that is formed in the cylinder portion and that opens to face the mating surface, and a valve seat is formed in a bottom portion of the valve housing portion. A stopper is formed at a position of the valve storage portion that is inserted from the opening by a certain distance, and a lid with a vent hole inserted from the opening side of the valve storage portion is disposed at a position that contacts the stopper, and the lid with the vent hole is provided. And a valve body that opens and closes by moving between the valve seat and the valve seat,
A vertical engine characterized in that a pressing portion having elasticity is provided around the ventilation path formed in the gasket, and the lid with the vent hole is repelled toward the stopper by the pressing portion. Lubrication structure.

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