JP2007138732A - Relief valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relief valve which fulfills reliable defoaming function by adapting to an increase in discharged oil volume from an outlet and an increase in discharge pressure while avoiding an increase in the size of the skirt shape. <P>SOLUTION: This relief valve comprises a cylindrical valve housing fitted to an engine body continuously with a relief valve and having an outlet at the axial intermediate portion, a valve element slidably fitted to the valve housing by communicating a relief passage with the outlet when the hydraulic pressure in the relief passage is increased to a predetermined one or above, and a skirt having an upper end above the outlet and fixed to the valve housing to guide the oil discharged from the outlet to the lower side. An annular recessed part 54 is formed in the intermediate outer periphery of the valve housing 44 on the underside of the outlet 43. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cylindrical valve housing that is attached to an engine body so as to extend up and down through a relief passage provided in the engine body through a discharge port of an oil pump, and is provided with a discharge port at an axially intermediate portion. A valve body slidably fitted to the valve housing so that the relief passage communicates with the discharge port when the hydraulic pressure of the relief passage becomes equal to or higher than a predetermined hydraulic pressure, and surrounds the valve housing In addition, the present invention relates to a relief valve that is formed in an umbrella shape and has an upper end that is fixed to the valve housing above the discharge port so that oil discharged from the discharge port is guided downward.

Such a relief valve is known from, for example, Patent Document 1 and the like, and bubbles are generated when oil discharged from the discharge port of the valve housing is returned to the oil storage chamber formed in the lower part of the engine body. In order to prevent this, the valve housing is covered with an umbrella-like skirt below the outlet.
JP 2001-207818 A

  By the way, in order to achieve a reliable defoaming function in response to an increase in the amount of oil discharged from the discharge port of the relief valve and an increase in the discharge pressure, the flow passage area between the valve housing and the skirt should be increased. It is not easy to change the inclination angle and size of the skirt because of the requirement for downsizing the internal combustion engine.

  The present invention has been made in view of such circumstances, and avoids an increase in the size of the skirt shape, while also ensuring defoaming in response to an increase in the amount of oil discharged from the discharge port and an increase in the discharge pressure. It is an object of the present invention to provide a relief valve that can perform its function.

  In order to achieve the above-mentioned object, the invention according to claim 1 is attached to the engine body so as to extend up and down continuously to the relief passage provided in the engine body through the discharge port of the oil pump, and in the axial intermediate portion. A cylindrical valve housing provided with a discharge port, and a slidable fit in the valve housing so that the relief channel communicates with the discharge port when the hydraulic pressure of the relief channel exceeds a predetermined hydraulic pressure. The valve body is formed in an umbrella shape so as to surround the valve housing, and an upper end portion is fixed to the valve housing above the discharge port so as to guide oil discharged from the discharge port downward. A relief valve having a skirt is characterized in that an annular recess is formed in the outer periphery of the intermediate portion of the valve housing below the discharge port. .

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the lower end of the skirt is arranged at a position corresponding to an intermediate portion of the annular recess.

  Furthermore, in the invention of claim 3, in addition to the structure of the invention of claim 1 or 2, the upper end portion of the valve housing forming the inlet is liquid-tightly fitted into the relief passage, and the valve housing The receiving part which receives a lower end is provided in the said engine main body, It is characterized by the above-mentioned.

  According to the first aspect of the present invention, the annular recess is formed on the outer periphery of the intermediate portion of the valve housing, so that the flow passage area between the valve housing and the skirt is increased by avoiding the enlargement of the skirt shape. A reliable defoaming function can be exhibited in response to an increase in the amount of oil discharged from the tank and an increase in the discharge pressure. Moreover, the annular recess is formed on the outer periphery of the intermediate portion of the valve housing below the discharge port, and the high pressure on the relief passage side does not act on the valve housing below the discharge port. The strength of the valve housing is not impaired by the formation of, and can contribute to weight reduction of the relief valve.

  According to the second aspect of the present invention, the oil discharged between the valve housing and the skirt can be discharged so as to be spread radially by being guided by the lower end of the annular recess, and the defoaming effect can be enhanced. .

  Further, according to the invention described in claim 3, the valve housing is pushed downward by the hydraulic pressure of the relief passage. However, since the annular recess is formed in the intermediate portion of the valve housing, the valve housing is provided in the engine body. The seating area of the lower end of the valve housing at the receiving portion can be set relatively large while increasing the flow path area between the valve housing and the skirt, and a large load acts on the lower end of the valve housing. Avoiding this, the valve housing can be securely attached to the engine body.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 3 show an embodiment of the present invention, FIG. 1 is a side view of an internal combustion engine, FIG. 2 is an enlarged vertical side view of the main part of FIG. 1, and FIG. 3 is a line 3-3 in FIG. It is sectional drawing.

  First, in FIG. 1, an engine main body 5 having a cylinder axis inclined upward is mounted on a body frame of a motorcycle. The engine main body 5 includes a cylinder barrel 6 and a lower portion of the cylinder barrel 6. A cylinder block 8 integrally having an upper case 7 connected to the lower case 9, a lower case 9 coupled to the lower portion of the cylinder block 8 so as to form a crankcase 10 in cooperation with the upper case 7, and a lower portion of the lower case 9, The upper case 7 and the lower case include an oil pan 11 coupled to the lower part of the crankcase 10, a cylinder head 12 coupled to the upper part of the cylinder block 8, and a head cover 13 coupled to the upper part of the cylinder head 12. 9, the coupling surface 14 is inclined forward and downward when mounted on a motorcycle. It is sea urchin set.

  A crankshaft 15 having an axis along the width direction of the motorcycle is rotatably supported between the upper case 7 and the lower case 9 constituting the crankcase 10, and the crankshaft 15 is attached to the upper case 7. The rotational power from the starter motor 16 to be attached is input via the starter gear transmission mechanism 17.

  The output of the crankshaft 15 is shifted by a transmission 18 and transmitted to a rear wheel as a drive wheel. The transmission 18 has an axis parallel to the crankshaft 15 and has an upper case 7 and a lower case. Between the main shaft 19 rotatably supported between the main shaft 19 and the counter shaft 20 having an axis parallel to the main shaft 19 and rotatably supported by the lower case 9. A gear train of gears is provided.

  A start clutch 21 interposed between the crankshaft 15 and the main shaft 19 is attached to one end of the main shaft 19, and the start clutch 21 is in a connected state in response to a rider's speed change operation. The power from the crankshaft 15 is transmitted to the main shaft 19.

  A valve operating mechanism 24 including an intake side camshaft 22 and an exhaust side camshaft 23 is accommodated between the cylinder head 12 and the head cover 13, and the intake side camshaft 22 and the exhaust gas that are rotatably supported by the cylinder head 12. The rotational power of the crankshaft 15 is reduced to ½ and transmitted to the side camshaft 23 by the timing transmission means 26 including the timing chain 25.

  Referring also to FIG. 2, an oil pump 28 having a rotation axis parallel to the crankshaft 15 is attached to the lower case 9 of the crankcase 10, and a drive sprocket fixed to the main shaft 19 of the transmission 18. An endless chain 32 is wound around 30 and a driven sprocket 31 fixed to the rotating shaft 29 of the oil pump 28.

  Oil stored in an oil storage chamber 33 formed in the oil pan 11 is pumped up by an oil pump 28 via an oil strainer 34. Further, the lower case 9 is provided with a discharge path 35 extending in parallel with the coupling surface 14 of the upper case 7 and the lower case 9 so as to communicate with the discharge port 36 of the oil pump 28, and the oil from the oil pump 28 is discharged from the lower case 9. It is discharged into the passage 35. In addition, a relief passage 37 is provided in the lower case 9 so as to branch at a right angle from the discharge passage 35 so as to communicate with the upper end portion of the discharge passage 35. The relief passage 37 is connected to the relief passage 37. By the action, the oil pressure in the discharge passage 35 is kept constant.

  By the way, the oil is supplied from the main gallery 40 provided in the lower case 9 of the crankcase 10 to the lubricated portions of the engine body 5 such as between the crank journal wall 39 ... and the crankshaft 15 provided in the crankcase 10. The main gallery 40 is connected to the discharge passage 35 via an oil filter 41 and an oil cooler 42.

  That is, the oil discharged from the oil pump 28 is regulated by the relief valve 38, purified by the oil filter 41, and then cooled by the oil cooler 42 and guided to the main gallery 40 as shown by the arrows in FIG. become.

  Referring also to FIG. 3, the relief valve 38 is constructed according to the present invention, and is attached between the lower case 9 and the oil pan 11 of the engine body 5 so as to extend up and down continuously with the relief passage 37. And a cylindrical valve housing 44 provided with a discharge port 43 at an intermediate portion in the axial direction, and the relief passage 37 communicated with the discharge port 43 when the hydraulic pressure of the relief passage 37 exceeds a predetermined hydraulic pressure. The valve body 45 is slidably fitted to the valve housing 44, and the upper portion is formed in a portion surrounding the discharge port 43 to form an umbrella and guide the oil discharged from the discharge port 43 downward. Has a skirt 46 fixed to the valve housing 44 above the outlets 43.

  The relief passage 37 is provided in the lower case 9 so that the lower end thereof opens to the oil storage chamber 33 side and is provided in the lower case 9, and the upper end portion of the valve housing 44 forming the inflow port 47 is formed at the inflow port 47. Is connected to the lower end of the relief passage 37 in a fluid-tight manner. That is, an O-ring 48 is attached to the outer periphery of the valve housing 44 at the fitting portion to the relief passage 37.

  On the other hand, the oil pan 11 in the engine body 5 is provided with a receiving portion 49 for receiving the lower end of the valve housing 44, and the receiving portion 49 is formed in a cylindrical shape so as to extend vertically. Thus, the coupling surface 14 of the upper case 7 and the lower case 9 is inclined forward and downward, and the valve housing 44 is coaxially connected to the relief passage 37 branched at right angles from the discharge passage 35 extending parallel to the coupling surface 14. Therefore, the upper end surface of the receiving portion 49 is formed to be inclined so as to abut on the lower end of the valve housing 44 at a right angle. In addition, a notch 50 is provided in a part along the circumferential direction of the receiving portion 49.

  When the upper end of the valve housing 44 is connected to the lower case 9 in a fluid-tight manner so that the upper end portion of the valve housing 44 is coaxially connected to the relief passage 37, the discharge port 43. A valve body 45, which is provided in the middle in the axial direction and is slidably fitted to the valve housing 44 so as to switch between communication and blocking between the inlet 47 and the outlet 43, has a closed upper end. It is formed in a bottom cylindrical shape.

  In addition, a stopper pin 50 having an axis along the one diameter line is inserted into the valve housing 44 above the discharge port 43... The valve body 45 at the upper limit position blocks between the inflow port 47 and the discharge port 43.

  A disc-shaped retainer 52 is inserted into the lower portion of the valve housing 44 so that the downward movement is restricted by a retaining ring 51 mounted on the inner surface of the lower end of the valve housing 44. The retainer 52 and the valve A valve spring 53 that biases the valve body 45 upward is contracted between the bodies 45. Thus, the valve opening direction force that presses the valve body 45 downward by the hydraulic pressure of the inlet 47 leading to the relief passage 37 causes the valve body 53 to urge the valve body 45 upward by the valve spring 53. When this force is exceeded, the valve body 45 moves downward so that the inlet 47 communicates with the outlets 43. That is, the hydraulic pressures of the relief passage 37 and the discharge passage 35 are maintained constant by the action of the relief valve 38.

  The skirt 46 is formed in order from the upper end thereof, a small diameter cylindrical portion 46a press-fitted into the valve housing 44, and a small diameter end connected coaxially to the lower end of the small diameter cylindrical portion 46a and having a larger diameter as it goes downward. The tapered portion 46b and the large-diameter cylindrical portion 46c coaxially connected to the lower end, which is the large-diameter end of the tapered portion 46b, are integrally formed. The small-diameter cylindrical portion 46a is integrated with the valve housing 44 of the stopper pin 50. In order to prevent disengagement from the stopper pin 50, the stopper pin 50 is fixed to the valve housing 44 by press-fitting or the like so as to cover both ends of the stopper pin 50. Thus, the valve housing 44 is surrounded by the tapered portion 46 b and the large diameter cylindrical portion 46 c of the skirt 46, and the tapered portion 46 b and the large diameter cylindrical portion 46 c form an umbrella shape surrounding the valve housing 44.

  In addition, an annular recess 54 is formed in the outer periphery of the intermediate portion of the valve housing 44 below the discharge port 43. The lower end of the skirt 46, that is, the lower end of the large-diameter cylindrical portion 46 c is formed in the intermediate portion of the annular recess 54. It is arranged at the corresponding position.

  Next, the operation of this embodiment will be described. When oil discharged from the discharge ports 43 provided in the valve housing 44 of the relief valve 38 is returned into the oil storage chamber 33 in the oil pan 11, bubbles are generated. In order to prevent the occurrence, the upper end portion of the skirt 46 formed in an umbrella shape so as to surround the discharge ports 43 is fixed to the valve housing 44 above the discharge ports 43. An annular recess 54 is formed on the outer periphery of the intermediate portion of the valve housing 44 below 43. Therefore, it is possible to avoid an increase in the shape of the skirt 46 and increase the flow passage area between the discharge ports 43 and the skirts 46, and increase and discharge the amount of oil discharged from the discharge ports 43. A reliable defoaming function can be exhibited in response to higher pressures. Moreover, the annular recess 54 is formed on the outer periphery of the intermediate portion of the valve housing 44 below the discharge port 43... And the high pressure on the relief passage 37 side acts on the valve housing 44 below the discharge port 43. Therefore, the formation of the annular recess 54 does not impair the strength of the valve housing 44, and can contribute to the weight reduction of the relief valve 38.

  Further, since the lower end of the skirt 46 is disposed at a position corresponding to the intermediate portion of the annular recess 54, the discharged oil flowing between the valve housing 44 and the skirt 46 is guided by the lower end of the annular recess 54 and discharged so as to spread radially. The defoaming effect can be enhanced.

  Further, the upper end portion of the valve housing 44 that forms the inlet 47 is liquid-tightly fitted into the relief passage 37, and a receiving portion 49 that receives the lower end of the valve housing 44 is provided in the oil pan 11. Although it is pressed against the receiving portion 49 side by the hydraulic pressure of the relief passage 37, the annular recess 54 is formed in the intermediate portion of the valve housing 44, so that the seating area of the lower end of the valve housing 44 at the receiving portion 49 can be reduced by the valve. The flow path area between the housing 44 and the skirt 46 can be set to be relatively large while avoiding a large load from concentrating on the lower end of the valve housing 44 to ensure that the valve housing 44 is securely attached to the engine body 5. Can be installed on.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

It is a side view of an internal combustion engine. It is a principal part expansion vertical side view of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2.

Explanation of symbols

5 ... Engine body 28 ... Oil pump 36 ... Discharge port 37 ... Relief passage 38 ... Relief valve 43 ... Discharge port 44 ... Valve housing 45 ... Valve body 46 ..Skirt 47 ... inlet 49 ... receiving part 54 ... annular recess

Claims (3)

  The oil pump (28) is attached to the engine main body (5) so as to extend vertically through the relief passage (37) provided in the engine main body (5) through the discharge port (36) and at an axially intermediate portion. A cylindrical valve housing (44) provided with a discharge port (43) and the relief passage (37) to the discharge port (43) in response to the hydraulic pressure of the relief passage (37) becoming a predetermined hydraulic pressure or higher. A valve body (45) that is slidably fitted to the valve housing (44) so as to communicate with the valve housing (44), is formed in an umbrella shape so as to surround the valve housing (44), and from the discharge port (43). In the relief valve, the upper end of the relief valve has a skirt (46) fixed to the valve housing (44) above the discharge port (43) so as to guide the discharged oil downward. Relief valve, characterized in that the annular recess (54) is formed in the intermediate portion outer periphery of the valve housing even below the outlet (43) (44).   The relief valve according to claim 1, wherein a lower end of the skirt (46) is arranged at a position corresponding to an intermediate portion of the annular recess (54).   An upper end portion of the valve housing (44) forming the inflow port (47) is fluid-tightly fitted into the relief passage (37), and a receiving portion (49) for receiving the lower end of the valve housing (44) is the engine. Relief valve according to claim 1 or 2, characterized in that it is provided in the body (5).

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