JP2016035237A - PCV valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PCV valve which enables improvement of the sealability when the valve is closed to prevent back flow.SOLUTION: A PCV valve 10 includes: a case 12; a valve body 14; and a valve spring 16. A blow-by gas, which re-flows from a crank chamber of an internal combustion engine to an intake passage, flows in the case 12. The valve body 14 is provided in the case 12 so as to move in an axial direction and adjusts a flow rate of the blow-by gas. The valve spring 16 is formed by a coil spring which biases the valve body 14 in a valve closing direction. A valve seat part 23 having a blow-by gas inlet hole 25 is provided at the case 12. A flange part 32 which is seated on or separates from the valve seat part 23 is provided at the valve body 14. A valve seat surface, in which an inner diameter increases toward the flange part 32 side, is formed at the valve seat part 23. A valve part surface having a shape, which makes line contact with the valve seat surface when the valve is closed, is formed at the flange part 32.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a PCV valve (positive crankcase ventilation valve) for adjusting the flow rate of blow-by gas recirculated from a crank chamber of an internal combustion engine to an intake passage.

  A conventional example of a PCV valve will be described. FIG. 10 is a sectional view showing a PCV valve. As shown in FIG. 10, the PCV valve 100 includes a case 102, a valve body 104, and a valve spring 106. A blow-by gas recirculated from a crank chamber of an internal combustion engine (not shown) to the intake passage flows through the gas passage 108 formed in the case 102. The valve body 104 is movably provided in the case 102 and adjusts the flow rate of blow-by gas. The valve spring 106 is a coil spring, and is interposed between the case 102 and the valve body 104. The valve spring 106 urges the valve body 104 in the valve closing direction (rightward in FIG. 10). The case 102 is provided with a valve seat 110 having a blow-by gas inlet 111. The valve body 104 is provided with a flange-shaped valve portion 113 that is seated on and separated from the valve seat portion 110. Such a PCV valve is described in Patent Document 1, for example.

JP 2009-293599 A

  The PCV valve 100 is closed when a backflow occurs due to a backfire or the like from a combustion chamber (not shown) of the internal combustion engine. At this time, the valve portion 113 of the valve body 104 needs to be seated on the valve seat portion 110 of the case 102 over the entire circumference. However, according to the conventional example, the contact surface between the valve portion 113 and the valve seat portion 110 is formed by a plane orthogonal to the axis. For this reason, when the valve body 104 is inclined with respect to the axis 102L of the case 102 (see the two-dot chain line 104 in FIG. 10), the valve portion 113 cannot be seated on the valve seat portion 110 by surface contact when the valve is closed. . That is, since the valve portion 113 comes into contact with the valve seat portion 110, the valve seat portion 110 and the valve portion 113 cannot be sealed over the entire circumference. For this reason, there existed a problem that the sealing performance at the time of valve closing fell and the backflow could not be prevented. When the PCV valve 100 is installed in a horizontal state, the valve body 104 often tilts so that the downstream end portion (left end portion in FIG. 10) of the valve body 104 is lowered downward due to its own weight.

  The problem to be solved by the present invention is to provide a PCV valve that improves the sealing performance when the valve is closed and can prevent backflow.

  According to a first aspect of the present invention, there is provided a case in which blow-by gas recirculated from a crank chamber of an internal combustion engine to an intake passage flows, a valve body provided in the case so as to be movable in an axial direction, and adjusting a flow rate of blow-by gas, A valve spring comprising a coil spring for urging the valve body in the valve closing direction, and the case is provided with a valve seat portion having a blow-by gas inlet, and the valve body is provided with respect to the valve seat portion. The valve seat is provided with a valve portion for seating and separating, and the valve seat portion is formed with a valve seat surface that gradually increases in inner diameter toward the valve portion side. A closing portion having a shape in line contact with the valve seat surface of the valve seat portion when the valve is closed is formed. According to this configuration, regardless of whether or not the axis of the valve body is aligned with the axis of the case, the closing portion of the valve portion may be seated on the valve seat surface of the valve seat portion by line contact when the valve is closed. it can. For this reason, the space between the valve seat portion and the valve portion can be sealed over the entire circumference. Therefore, the sealing performance when the valve is closed can be improved, and backflow can be prevented.

  According to a second invention, in the first invention, the valve seat surface of the valve seat portion is formed in a tapered shape having an inner diameter gradually increasing toward the valve portion side, and the closing portion of the valve portion is formed of the valve The valve portion surface has a tapered shape that gradually decreases the outer diameter toward the seat portion side, and the taper angle of the valve seat surface is larger than the taper angle of the valve portion surface. According to this configuration, when the valve is closed, the valve portion surface of the valve portion can be seated on the valve seat surface of the valve seat portion by line contact.

  In a third aspect based on the first aspect, the closing portion of the valve portion comprises an annular convex portion that makes line contact with the valve seat surface of the valve seat portion. According to this configuration, when the valve is closed, the annular convex portion of the valve portion can be seated on the valve seat surface of the valve seat portion by line contact.

  According to a fourth aspect of the present invention, there is provided a case in which blow-by gas recirculated from the crank chamber of the internal combustion engine to the intake passage flows, a valve body provided in the case so as to be movable in the axial direction and adjusting the flow rate of the blow-by gas, A valve spring comprising a coil spring for urging the valve body in the valve closing direction, and the case is provided with a valve seat portion having a blow-by gas inlet, and the valve body is provided with respect to the valve seat portion. The valve portion is provided with a valve portion to be seated and separated, and the valve portion is formed with a valve portion surface having an inner diameter gradually increasing toward the valve seat portion side. Is formed with an annular convex portion in which the valve portion surface makes line contact. According to this configuration, when the valve is closed, the valve portion surface of the valve portion can be seated on the annular convex portion of the valve seat portion by line contact.

  According to a fifth aspect of the present invention, there is provided a case in which blow-by gas recirculated from the crank chamber of the internal combustion engine to the intake passage flows, a valve body provided in the case so as to be movable in the axial direction and adjusting the flow rate of the blow-by gas, A valve spring comprising a coil spring for urging the valve body in the valve closing direction, and the case is provided with a valve seat portion having a blow-by gas inlet, and the valve body is provided with respect to the valve seat portion. The valve seat is provided with a valve portion that is seated and separated, and the valve seat portion is formed with a valve seat surface that gradually decreases in outer diameter toward the valve portion side. Is formed with a concave portion having an annular mouth edge with which the valve seat surface comes into line contact. According to this configuration, when the valve is closed, the annular mouth edge portion of the valve portion can be seated on the valve seat surface of the valve seat portion by line contact.

  In a sixth aspect of the present invention based on any one of the first to sixth aspects, the valve body has a wall portion that blocks ventilation in a valve main body portion formed in a hollow cylindrical shape. According to this structure, a valve body can be reduced in weight compared with a solid valve body.

  According to a seventh invention, in any one of the first to seventh inventions, the valve portion of the valve body is formed in a flange shape that also serves as a spring receiver of the valve spring. According to this structure, the structure of a valve body can be simplified compared with the case where a valve part and a spring receiver are provided in a valve body separately.

It is sectional drawing which shows the PCV valve | bulb concerning Embodiment 1. FIG. It is the II-II sectional view taken on the line of FIG. It is sectional drawing which shows the valve closing state of the cutoff valve structure part. It is sectional drawing which shows the valve opening state of a cutoff valve structure part. It is sectional drawing which shows a valve closing state when the valve body of a cutoff valve structure part inclines. It is sectional drawing which shows the cutoff valve structure part concerning Embodiment 2. FIG. It is sectional drawing which shows the cutoff valve structure part concerning Embodiment 3. FIG. It is sectional drawing which shows the cutoff valve structure part concerning Embodiment 4. FIG. It is sectional drawing which shows the cutoff valve structure part concerning Embodiment 5. FIG. It is sectional drawing which shows the PCV valve | bulb concerning a prior art example.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1] Embodiment 1 will be described. 1 is a sectional view showing a PCV valve, and FIG. 2 is a sectional view taken along the line II-II in FIG. As shown in FIG. 1, the PCV valve 10 includes a case 12, a valve body 14, and a valve spring 16. The case 12 is made of, for example, resin and is formed in a hollow cylindrical shape. The hollow portion of the case 12 is a gas passage 18 that extends in the axial direction (left-right direction in FIG. 1). The case 12 is installed in a horizontal state with respect to, for example, a cylinder head cover (not shown) of the internal combustion engine. In addition, blow-by gas recirculated from the crank chamber of the internal combustion engine (not shown) to the intake passage flows through the gas passage 18. In FIG. 1, the right side corresponds to the upstream side of the gas passage 18, and the left side corresponds to the downstream side of the gas passage 18.

  The case 12 is configured by joining a pair of case halves 12a and 12b divided in two in the axial direction. An annular plate-like measuring plate 20 is concentrically sandwiched between the case halves 12a and 12b. The circular hollow hole of the measuring plate 20 is a measuring hole 21. A valve seat portion 23 is formed at the upstream end portion of the case half body 12a on the upstream side (right side in FIG. 1). The valve seat portion 23 is formed in an annularly and concentrically projecting radially inward direction at the upstream end portion of the case half 12a. A circular hollow hole in the valve seat portion 23 is an inlet hole 25 of the gas passage 18. In addition, an outlet hole 27 of the gas passage 18 is formed at the distal end of the case half 12b on the downstream side (left side in FIG. 1). The inlet hole 25 corresponds to “inlet” and “valve hole” in this specification. The outlet hole 27 corresponds to an “exit” in this specification.

  The valve body 14 is provided in the gas passage 18 in the case 12 so as to be movable in the axial direction (left-right direction in FIG. 1). The valve body 14 is made of, for example, resin, and includes a valve main body portion 30, an end wall portion 31, and a flange portion 32. The valve body 30 is formed in a hollow cylindrical shape. The end wall portion 31 closes the open end surface on the downstream side (front end side) of the valve main body portion 30. The flange portion 32 is formed so as to project radially and outwardly in an annular shape and concentrically at an upstream end (base end side) end portion of the valve main body portion 30. The outer peripheral surface of the flange part 32 is slidably contactable with the inner peripheral surface of the upstream case half 12a (see FIG. 2). An appropriate number (three are shown in FIG. 2) of string-like notches 33 that allow the passage of blow-by gas is formed on the outer peripheral portion of the flange portion 32. The end wall portion 31 corresponds to a “wall portion that blocks ventilation” in the present specification. The flange portion 32 corresponds to a “valve portion” in the present specification.

  The downstream half of the valve main body 30 is formed in a tapered shape. A tapered measuring surface 35 is formed on the outer peripheral surface of the half portion on the downstream side of the valve main body 30. The valve main body 30 is inserted into the measuring hole 21 from the upstream side. A measuring portion 37 is constituted by the inner peripheral surface of the measuring hole 21 and the measuring surface 35 of the valve body 14. As the valve body 14 moves upstream, that is, retracts, the effective opening area of the metering portion 37, that is, the passage cross-sectional area is increased. Conversely, the passage cross-sectional area of the measuring portion 37 is reduced as the valve element 14 moves downstream, that is, advances.

  The valve spring 16 is interposed between the case 12 and the valve body 14. Specifically, the valve spring 16 is a coil spring, and is interposed between the flange portion 32 and the measuring plate 20 in a state of being fitted to the valve main body portion 30 of the valve body 14. The valve spring 16 urges the valve body 14 in the valve closing direction (rightward in FIG. 1), that is, toward the upstream side. The measuring plate 20 and the flange portion 32 also serve as a spring receiver for the valve spring 16. A cushion spring 39 made of a coil spring is disposed in the downstream case half 12b. The cushion spring 39 elastically restricts excessive movement of the valve body 14 to the downstream side.

  When the PCV valve 10 is closed, the valve body 14 is moved to the last retracted position, and the flange portion 32 of the valve body 14 is seated on the valve seat portion 23 of the case 12 so that the inlet hole 25 of the gas passage 18 is opened. Cut off. The valve seat portion 23 and the flange portion 32 constitute a “shut-off valve component” referred to in this specification. The shut-off valve component will be described. 3 is a cross-sectional view showing the closed state of the shut-off valve component, FIG. 4 is a cross-sectional view showing the valve-open state, and FIG. 5 is a cross-sectional view showing the valve-closed state when the valve body is also tilted.

  As shown in FIG. 4, the flange portion 32 is formed in a folded shape with respect to the valve body portion 30. Thereby, the flange part 32 is formed with a tapered valve part surface 41 that gradually decreases in outer diameter toward the valve seat part 23 side. The valve portion surface 41 is formed with a predetermined taper angle α with respect to the axis 14L of the valve body 14. The valve seat portion 23 is formed with a tapered valve seat surface 43 that gradually increases in inner diameter toward the flange portion 32 side. The valve seat surface 43 is formed with a predetermined taper angle β with respect to the axis of the case 12. The taper angle β is larger than the taper angle α. The valve surface 41 corresponds to a “closing portion” in the present specification.

  As shown in FIG. 3, when the axis 14L of the valve body 14 is aligned with the axis 12L of the case 12, the valve seat surface 43 of the valve seat portion 23 and the valve portion surface 41 of the flange portion 32 are closed. Line contact with each other at the time of valve. Further, as shown in FIG. 5, even when the axis 14 </ b> L of the valve body 14 is inclined with respect to the axis 12 </ b> L of the case 12, the valve seat surface 43 of the valve seat portion 23 and the valve portion surface 41 of the flange portion 32. Are in line contact with each other when the valve is closed. That is, the valve seat surface 43 of the valve seat portion 23 and the valve portion surface 41 of the flange portion 32 have a shape that makes line contact with each other when the valve is closed.

  According to the PCV valve 10, the valve body 14 moves to a position where the biasing force of the valve spring 16 acting on the valve body 14, the pressure of the crank chamber (not shown) of the internal combustion engine, and the intake negative pressure are balanced. The flow rate of blow-by gas is adjusted by the movement of the valve body 14. Further, when a backflow occurs due to a backfire or the like from a combustion chamber (not shown) of the internal combustion engine, the PCV valve 10 is closed. That is, the flange portion 32 of the valve body 14 is seated on the valve seat portion 23 of the case 12.

  The valve seat portion 23 is formed with a valve seat surface 43 having an inner diameter that gradually increases toward the flange portion 32. The flange portion 32 is in line contact with the valve seat surface 43 of the valve seat portion 23 when the valve is closed. The valve part surface 41 of the shape to be formed is formed. Therefore, regardless of whether or not the axis of the valve body is aligned with the axis of the case, the valve surface 41 of the flange 32 is seated on the valve seat surface 43 of the valve seat by line contact when the valve is closed. (See FIGS. 3 and 5). For this reason, the space between the valve seat portion 23 and the flange portion 32 can be sealed over the entire circumference. Therefore, the sealing performance when the valve is closed can be improved, and backflow can be prevented.

  Further, the valve seat surface 43 of the valve seat portion 23 is formed in a tapered shape with an inner diameter gradually increasing toward the flange portion 32 side, and the valve portion surface 41 of the flange portion 32 is outwardly facing toward the valve seat portion 43 side. A taper shape with a gradually decreasing diameter is formed, and the taper angle β of the valve seat surface 43 is larger than the taper angle α of the valve portion surface 41 (see FIG. 4). Therefore, when the valve is closed, the valve portion surface 41 of the flange portion 32 can be seated on the valve seat surface 43 of the valve seat portion 23 by line contact.

  Moreover, the valve body 14 has the end wall part 31 in the valve main-body part 30 formed in the hollow cylindrical shape (refer FIG. 1). Therefore, the weight of the valve body 14 can be reduced as compared with a solid valve body.

  Moreover, the flange part 32 of the valve body 14 is formed in the flange shape which serves as the spring receiver of the valve spring 16 (refer FIG. 1). Therefore, the configuration of the valve body 14 can be simplified as compared with the case where the flange portion 32 and the spring receiver are individually provided on the valve body 14.

[Embodiment 2] Embodiment 2 will be described. This embodiment is a modification of the first embodiment. FIG. 6 is a cross-sectional view showing the shut-off valve component. As shown in FIG. 6, in this embodiment, a flange portion 49 orthogonal to the axis 14 </ b> L of the valve body 14 is formed instead of the flange portion 32 in the first embodiment (see FIG. 4). An annular convex portion 50 is formed on the flange portion 32. The annular convex portion 50 is formed in a semicircular cross section, and can come into line contact with the valve seat surface 43 of the valve seat portion 23. Therefore, when the valve is closed, the annular convex portion 50 of the flange portion 49 can be seated on the valve seat surface 43 of the valve seat portion 23 by line contact. The annular protrusion 50 corresponds to a “closing portion” in this specification.

[Embodiment 3] Embodiment 3 will be described. This embodiment is a modification of the second embodiment. FIG. 7 is a cross-sectional view showing the shut-off valve component. As shown in FIG. 7, a valve seat surface 52 having a concave arcuate cross section is formed in the valve seat portion 23 in place of the valve seat surface 43 in the second embodiment (see FIG. 6). Therefore, when the valve is closed, the annular convex portion 50 of the flange portion 49 can be seated on the valve seat surface 52 of the valve seat portion 23 by line contact.

[Embodiment 4] Embodiment 4 will be described. This embodiment is a modification of the second embodiment. FIG. 8 is a cross-sectional view showing the shut-off valve component. As shown in FIG. 8, in the present embodiment, a flange portion 54 in which the annular convex portion 50 is omitted is formed instead of the flange portion 49 in the second embodiment (see FIG. 6). The flange portion 54 is formed with a tapered valve portion surface 55 that gradually increases its inner diameter toward the valve seat portion 23 side. Further, an annular convex portion 57 is formed on the valve seat portion 23 in place of the valve seat surface 43 (see FIG. 6). The annular convex portion 57 is formed in a semicircular cross section, and the valve portion surface 55 can be brought into line contact. Therefore, when the valve is closed, the valve portion surface 55 of the flange portion 54 can be seated on the annular convex portion 57 of the valve seat portion 23 by line contact.

[Embodiment 5] Embodiment 5 will be described. This embodiment is a modification of the second embodiment. FIG. 9 is a cross-sectional view showing the shut-off valve component. As shown in FIG. 9, the valve seat portion 23 is formed with a valve seat surface 59 that gradually decreases in outer diameter toward the flange portion side, instead of the valve seat surface 43 in the second embodiment (see FIG. 6). ing. Moreover, it replaces with the flange part 49 (refer FIG. 6), and the flange part 61 in which the cyclic | annular convex part 50 was abbreviate | omitted is formed. The flange portion 61 is formed with a recess 62 having an annular mouth edge 62a. The annular mouth edge 62a can be brought into line contact with the valve seat surface 59. The recess 62 is a hollow portion of the valve main body 30. The annular mouth edge 62a is formed in a circular arc shape in cross section. Therefore, when the valve is closed, the annular mouth edge 62a of the flange portion 61 can be seated on the valve seat surface 59 of the valve seat portion 23 by line contact.

[Other Embodiments] The present invention is not limited to the embodiments and can be modified without departing from the gist of the present invention. For example, the installation mode of the case 12 with respect to the internal combustion engine may be changed as appropriate. For example, the case 12 may be installed in a vertical shape or in an inclined shape with respect to the horizontal direction and / or the vertical direction. Further, the case 12 may have an integral structure. Further, the measurement hole 21 may be formed in the case 12 itself. Further, the valve seat portion may be formed by attaching a member having the valve seat portion to the case 12. Further, the valve body 14 may be formed in a solid shape. Further, the case 12 and / or the valve body 14 is not limited to resin, but may be made of metal. Further, the wall portion (end wall portion 31) of the valve body 14 may be disposed at an arbitrary position in the axial direction of the valve main body portion 30. For example, the wall portion of the valve body 14 may be an end wall portion that closes the opening end face on the downstream side of the valve main body portion 30, or may be a partition wall that partitions the hollow portion in the valve main body portion 30 in the axial direction.

DESCRIPTION OF SYMBOLS 10 ... PCV valve 12 ... Case 14 ... Valve body 16 ... Valve spring 23 ... Valve seat part 25 ... Inlet hole (inlet, valve hole)
30 ... Valve body 31 ... End wall (wall that blocks ventilation in the valve body)
32 ... Flange (valve)
41 ... Valve part surface (closing part)
43 ... Valve seat surface 45 ... Inlet hole (inlet, valve hole)
45a ... Annular mouth part 49 ... Flange part (valve part)
50 ... Annular convex part (closing part)
52 ... Valve seat surface 54 ... Flange (valve)
55 ... Valve portion surface 57 ... Annular convex portion 59 ... Valve seat surface 61 ... Flange portion (valve portion)
62 ... recessed portion 62a ... annular mouth edge

Claims (7)

A case where blow-by gas recirculated from the crank chamber of the internal combustion engine to the intake passage flows;
A valve body provided in the case so as to be movable in the axial direction and adjusting a flow rate of blow-by gas;
A valve spring comprising a coil spring that urges the valve body in the valve closing direction,
The case is provided with a valve seat having a blow-by gas inlet,
The valve body is provided with a valve portion that is seated and separated from the valve seat portion, and is a PCV valve,
The valve seat portion is formed with a valve seat surface that gradually increases the inner diameter toward the valve portion side,
The valve portion is formed with a closing portion having a shape in line contact with the valve seat surface of the valve seat portion when the valve is closed. The PCV valve according to claim 1,
The valve seat surface of the valve seat portion is formed in a tapered shape that gradually increases the inner diameter toward the valve portion side,
The closing part of the valve part consists of a tapered valve part surface that gradually decreases the outer diameter toward the valve seat part side,
A taper angle of the valve seat surface is larger than a taper angle of the valve portion surface. PCV valve. The PCV valve according to claim 1,
The closing part of the valve part is a PCV valve comprising an annular convex part in line contact with the valve seat surface of the valve seat part. A case where blow-by gas recirculated from the crank chamber of the internal combustion engine to the intake passage flows;
A valve body provided in the case so as to be movable in the axial direction and adjusting a flow rate of blow-by gas;
A valve spring comprising a coil spring that urges the valve body in the valve closing direction,
The case is provided with a valve seat having a blow-by gas inlet,
The valve body is provided with a valve portion that is seated and separated from the valve seat portion, and is a PCV valve,
The valve portion is formed with a valve portion surface that gradually increases the inner diameter toward the valve seat portion side,
The valve seat part is formed with an annular convex part in which the valve part surface makes line contact. PCV valve. A case where blow-by gas recirculated from the crank chamber of the internal combustion engine to the intake passage flows;
A valve body provided in the case so as to be movable in the axial direction and adjusting a flow rate of blow-by gas;
A valve spring comprising a coil spring that urges the valve body in the valve closing direction,
The case is provided with a valve seat having a blow-by gas inlet,
The valve body is provided with a valve portion that is seated and separated from the valve seat portion, and is a PCV valve,
The valve seat portion is formed with a valve seat surface that gradually decreases the outer diameter toward the valve portion side,
The valve portion is formed with a recess having an annular lip portion in line contact with the valve seat surface. The PCV valve according to any one of claims 1 to 5,
The said valve body is a PCV valve which has a wall part which interrupts | blocks ventilation | gas_flowing in the valve main-body part formed in the hollow cylinder shape. The PCV valve according to any one of claims 1 to 6,
The valve portion of the valve body is a PCV valve formed in a flange shape that also serves as a spring receiver for the valve spring.

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