JP2016180411A - valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compatibly improve the wear resistance of a sliding part and increase the flow amount of blow-by gas.SOLUTION: A PCV valve 40 has a valve element 46 stored in a case 42 having an inflow port 43 and an outflow port 44 in a reciprocative manner. A measurement part 56 is formed by the inner wall of the case 42. The valve element 46 has a base end side portion whose diameter is made larger than that of a front end side portion by a tapered part 62. With a change in the position of the tapered part 62 in the reciprocating direction of the valve element 46, blow-by gas flowing from the inflow port 43 to the outflow port 44 is measured. On the valve element 46, a plurality of ribbed guide parts 70 are formed which are protruded radially from the tapered part 62 while extending in the axial direction to come in slide contact with the measurement part 56 of the case 42. The guide parts 70 are each formed so that the width on the front end side of the valve element 46 is smaller than the width on the base end side thereof.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a PCV (Positive Crankcase Ventilation) valve used in a blow-by gas reduction device for an internal combustion engine (engine) in a vehicle such as an automobile.

A conventional example of a PCV valve will be described. 14 is a cross-sectional view showing the PCV valve, and FIG. 15 is a cross-sectional view taken along line XV-XV in FIG. 16 is a cross-sectional view showing a state in which the width of the guide portion of the PCV valve of FIG. 14 is widened, and FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG.
As shown in FIG. 14, the PCV valve 140 includes a hollow cylindrical case 142 having an inflow port 143 and an outflow port 144, and a valve body 146 that is accommodated in the case 142 so as to reciprocate. The inflow port 143 communicates with the inside of the cylinder head cover of the engine (internal combustion engine). Further, the outlet 144 is communicated with a passage portion on the downstream side of the throttle valve in the intake passage of the engine. Inside the case 142, between the inflow port 143 and the outflow port 144, a circular measuring section 156 having a predetermined inner diameter and axial length is formed by the inner wall of the case 142.

  The valve body 146 includes a columnar base shaft portion 160 and a tapered portion 162 that tapers from the base shaft portion 160 toward the distal end portion. The diameter of the tapered portion 162 is larger at the base end side (base shaft portion 160 side) than the tip end portion. Further, the tapered portion 162 of the valve body 146 is inserted into the measuring portion 156 from the inlet 143 side toward the outlet 144 side. In addition, a spring 166 that biases the valve body 146 toward the inflow port 143 is provided between the case 142 and the valve body 146 inside the case 142.

  In the PCV valve 140, when negative pressure generated in the intake passage of the engine is introduced into the case 142 through the outlet 144, the valve body 146 flows against the urging force of the spring 166 by the action of the negative pressure. Displacement to the outlet 144 side. Then, when the position of the tapered portion 162 in the reciprocating direction of the valve body 146 in the measuring portion 156 of the case 142 changes, the gap between the measuring portion 156 and the tapered portion 162, that is, the opening portion is passed. The blow-by gas flowing from the inflow port 143 to the outflow port 144 is measured (metered). 14 and 16, the valve body 146 is shown in an operating state corresponding to the WOT region of the engine.

Further, the tapered portion 162 of the valve body 146 has four rib-shaped ribs that project radially from the tapered portion 162 and extend in the axial direction and are slidably contactable with the measuring portion 156 of the case 142. A guide portion 170 is formed (see FIG. 15). A width 170W of the guide portion 170 of the valve body 146 (a dimension in a direction crossing the protruding direction of the guide portion 170) 170W is constant over the entire length. Therefore, when the valve body 146 is reciprocated, the guide body 170 is slidably brought into contact with the measuring portion 156 of the case 142, whereby the valve body 146 is guided in the axial direction.
Further, a PCV valve including a valve body having a plurality of rib-shaped guide portions that can be brought into sliding contact with the measuring portion of the case is described in Patent Document 1, for example.

JP 2007-182939 A

According to the conventional example, the width 170W of the guide portion 170 of the valve body 146 is constant over the entire length. For this reason, the performance contrary to the improvement of the wear resistance of the sliding portion by the measuring portion 156 and the guide portion 170 and the increase in the flow rate of the blow-by gas flowing through the opening between the measuring portion 156 and the valve body 146. It was difficult to achieve both. 14 and 15 show a case where the width 170W of the guide portion 170 is set small. 16 and 17 show a case where the width 170W of the guide portion 170 is set large. Comparing the two, when the width 170W of the guide portion 170 is set small (see FIGS. 14 and 15), the flow passage cross-sectional area of the opening between the measuring portion 156 and the tapered portion 162 is wide. While the gas flow rate can be increased, the contact area of the guide portion 170 with respect to the measuring portion 156 is reduced, so that the wear resistance of the sliding portion is inevitably lowered. Further, when the width 170W of the guide portion 170 is set large (see FIGS. 16 and 17), the contact area of the guide portion 170 with the measuring portion 156 is widened, so that the wear resistance of the sliding portion can be improved. On the other hand, since the flow passage cross-sectional area of the opening between the metering portion 156 and the valve body 146 is reduced, the flow rate of the blow-by gas must be reduced. Therefore, there is a problem that it is impossible to achieve both improvement in wear resistance of the sliding portion and increase in the flow rate of blow-by gas. In Patent Document 1, there is a problem similar to that of the conventional example. In the WOT (Wide Open Throttle) region of the engine, there is a demand to increase the flow rate of blow-by gas.
The problem to be solved by the present invention is to achieve both improvement in wear resistance of the sliding portion and increase in the flow rate of blow-by gas.

The above problem is solved by the first invention.
In the first invention, a valve body is accommodated in a case having an inflow port and an outflow port so as to be able to reciprocate, and a measuring portion having a circular cross section is formed by the inner wall of the case. The diameter of the proximal end portion is larger than the distal end portion by the formed tapered portion, and the distal end side portion of the valve body is inserted into the measuring portion of the case to change the position of the tapered portion in the reciprocating direction. Is a PCV valve that measures the blow-by gas flowing from the inlet to the outlet through the gap between the measuring portion and the tapered portion, and is projected radially from the tapered portion to the valve body and in the axial direction And a plurality of rib-shaped guide portions that are slidably contactable with the measuring portion of the case, and the guide portions have a width on the distal end side smaller than a width on the proximal end side of the valve body. It is formed as follows.

  According to this configuration, the valve body is formed with a plurality of rib-shaped guide portions that protrude radially from the tapered portion, extend in the axial direction, and are capable of sliding contact with the measuring portion of the case. In the reciprocating motion of the valve body, the valve body is guided in the axial direction by the plurality of guide portions slidingly contacting the measuring portion of the case. Thereby, the deflection of the valve body in the radial direction is prevented, and the operation stability of the valve body is improved. By the way, the guide part is formed so that the width on the distal end side is smaller than the width on the proximal end side of the valve body. For this reason, when the guide portion on the base end side of the valve body corresponds to the measuring portion of the case, the sliding portion by the measuring portion and the guide portion is increased by increasing the width of the guide portion on the base end side of the valve body. The wear resistance can be improved. Also, when the guide part on the tip side of the valve body corresponds to the metering part of the case, it is required to increase the flow rate of blow-by gas, so by reducing the width of the guide part on the tip side of the valve body The flow rate of blow-by gas can be increased. Therefore, it is possible to achieve both improvement in wear resistance of the sliding portion and increase in the flow rate of blow-by gas.

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. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. It is sectional drawing which shows the PCV valve | bulb in the engine idle region. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. It is a side view which shows a valve body. It is a block diagram which shows a blow-by gas reduction apparatus. It is a side view which shows the valve body concerning Embodiment 2. FIG. It is a side view which shows the valve body concerning Embodiment 3. FIG. It is a side view which shows the valve body concerning Embodiment 4. It is a side view which shows the valve body concerning Embodiment 5. FIG. It is a side view which shows the valve body concerning Embodiment 6. FIG. It is a side view which shows the valve body concerning Embodiment 7. FIG. It is sectional drawing which shows the PCV valve | bulb concerning a prior art example. It is XV-XV arrow directional cross-sectional view of FIG. It is sectional drawing which shows the state which widened the width | variety of the guide part of the PCV valve | bulb of FIG. FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 16.

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

[Embodiment 1]
Embodiment 1 will be described. For convenience of explanation, the PCV valve will be explained after explaining an example of the blow-by gas reducing device. FIG. 7 is a block diagram showing a blow-by gas reduction device.
As shown in FIG. 7, the blow-by gas reduction device 10 causes blow-by gas leaked from the combustion chamber (not shown) of the engine body 13 of the engine 12 which is an internal combustion engine into the crankcase 15 of the cylinder block 14 into the intake manifold 20. It is a system which is made to burn again in the combustion chamber by being introduced into.

  The engine body 13 includes the cylinder block 14, an oil pan 16 fastened to the lower surface side of the crankcase 15, a cylinder head 17 fastened to the upper surface side of the cylinder block 14, and an upper surface side of the cylinder head 17. The cylinder head cover 18 is fastened. The engine body 13 obtains driving force through a process such as intake, compression, explosion, and exhaust. Further, blow-by gas is generated in the engine main body 13, that is, in the crankcase 15 and in the cylinder head cover 18 communicating with the crankcase 15 as combustion occurs in the combustion chamber (not shown) of the engine main body 13. . Further, the inside of the cylinder head cover 18 and the inside of the crankcase 15 into which blow-by gas flows corresponds to “inside of the engine body” in this specification.

  The cylinder head cover 18 is provided with a fresh air inlet 18a and a blow-by gas outlet 18b. One end (downstream end) of the fresh air introduction passage 30 communicates with the fresh air introduction port 18a. One end (upstream end) of the blowby gas passage 36 is communicated with the blowby gas outlet 18b. The fresh air inlet 18 a and / or the blow-by gas outlet 18 b can be provided in the crankcase 15 instead of the cylinder head cover 18.

  One end (downstream end) of the intake manifold 20 is communicated with the cylinder head 17. The intake manifold 20 includes a surge tank 21. An air cleaner 25 communicates with the other end (upstream end) of the intake manifold 20 via a throttle body 24 and an intake pipe 23. The throttle body 24 includes a throttle valve 24a. The throttle valve 24a is connected to, for example, an accelerator pedal (not shown), and is opened and closed according to the depression amount (operation amount) of the pedal. The air cleaner 25 introduces air so-called fresh air, and has a built-in filter element 26 for filtering the fresh air. The air cleaner 25, the intake pipe 23, the throttle body 24, and the intake manifold 20 form a series of intake passages 27 for introducing fresh air, that is, intake air into the combustion chamber of the engine body 13. In the intake passage 27, a passage portion upstream of the throttle valve 24a is referred to as an upstream intake passage portion 27a, and a passage portion downstream of the throttle valve 24a is referred to as a downstream intake passage portion 27b.

  A fresh air inlet 29 is formed in the intake pipe 23. The fresh air inlet 29 communicates with the other end (upstream end) of the fresh air introduction passage 30. The fresh air introduction passage 30 is provided with a backflow prevention valve 32. The backflow prevention valve 32 allows the flow of so-called fresh air (see arrow Y1 in FIG. 7) from the intake passage portion 27a on the upstream side into the crankcase 15, and the flow in the reverse direction, that is, the backflow. (See arrow Y3 in FIG. 7). The surge tank 21 has a blow-by gas inlet 34 formed therein. The blow-by gas introduction port 34 communicates with the other end (downstream end) of the blow-by gas passage 36. The backflow prevention valve 32 is provided as necessary, and can be omitted.

  Next, the operation of the blowby gas reduction device 10 will be described. When the engine 12 is light and medium load, the throttle valve 24a is almost fully closed. For this reason, a negative pressure (a negative pressure that increases toward the vacuum side) greater than that of the upstream intake passage portion 27a is generated in the intake passage portion 27b downstream of the intake passage 27. Accordingly, the blow-by gas in the engine body 13 is introduced into the intake passage portion 27b on the downstream side through the blow-by gas passage 36 (see arrow Y2 in FIG. 7). At this time, the flow rate of blow-by gas flowing through the blow-by gas passage 36 is controlled by a PCV valve 40 (described later).

  Further, as the blow-by gas is introduced into the intake passage portion 27b on the downstream side from the engine body 13 through the blow-by gas passage 36, the backflow prevention valve 32 is opened. As a result, fresh air in the intake passage portion 27a upstream of the intake passage 27 is introduced into the engine body 13 through the fresh air introduction passage 30 (see arrow Y1 in FIG. 7). The fresh air introduced into the engine body 13 is introduced into the intake passage portion 27b on the downstream side through the blow-by gas passage 36 together with the blow-by gas (see arrow Y2 in FIG. 7). As described above, the inside of the engine body 13 is scavenged.

  Further, when the engine 12 is at a high load, the opening degree of the throttle valve 24a becomes large. Therefore, the pressure in the intake passage portion 27b on the downstream side of the intake passage 27 approaches the atmospheric pressure. Therefore, the blow-by gas in the engine main body 13 becomes difficult to be introduced into the intake passage portion 27b on the downstream side, and the pressure in the engine main body 13 also approaches atmospheric pressure. For this reason, the flow rate of fresh air introduced into the engine body 13 from the upstream intake passage portion 27a through the fresh air introduction passage 30 is also reduced. Further, by closing the backflow prevention valve 32, the backflow of blowby gas from the engine body 13 to the fresh air introduction passage 30 (see arrow Y3 in FIG. 7) is prevented.

  The blow-by gas passage 36 is provided with a PCV valve 40 for controlling the flow rate of blow-by gas. The PCV valve 40 controls, or measures, the flow rate of the blow-by gas in accordance with the differential pressure between the upstream pressure and the downstream pressure of the blow-by gas, that is, the intake negative pressure (also referred to as “boost pressure”). Thereby, blow-by gas having a flow rate corresponding to the amount of blow-by gas generated in the engine 12 can be caused to flow to the intake passage portion 27b on the downstream side.

  Next, the PCV valve 40 will be described. 1 is a sectional view showing a PCV valve, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. 1, and FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4, and FIG. 6 is a side view showing the valve body. For convenience of explanation, the left side of FIG. 1 will be described as the front side (front end side), and the right side will be described as the rear side (base end side).

  As shown in FIG. 1, the PCV valve 40 includes a hollow cylindrical case 42 having an inflow port 43 and an outflow port 44, and a valve body 46 that is accommodated in the case 42 so as to reciprocate. A hollow portion in the case 42 is a gas passage 48 extending in the axial direction (left-right direction in FIG. 1). A rear end portion (right end portion in FIG. 1) of the case 42 is connected to a passage portion on the upstream side of the blow-by gas passage 36 (see FIG. 7). Further, the front end portion (left end portion in FIG. 1) of the case 42 is connected to a passage portion on the downstream side of the blow-by gas passage 36. Further, the rear end portion of the case 42 may be connected to the blow-by gas outlet 18b of the cylinder head cover 18 (see FIG. 7).

  The case 42 is configured by joining a pair of front and rear case halves 42a and 42b that are divided into two in the axial direction (front-rear direction). Both case halves 42a, 42b are made of resin, for example. A sheet portion 50 that protrudes radially inward in a flange shape is formed concentrically at the center of the front case half 42a. A stepped surface 50 a is formed on the rear side surface of the sheet portion 50. A hollow cylindrical upstream wall surface 52 is formed in the rear case half 42b, that is, on the gas inflow side (right side in FIG. 1) of the gas passage 48. A hollow cylindrical downstream wall surface 54 is formed in front of the seat portion 50 of the front case half 42a, that is, on the gas outflow side (left side in FIG. 1).

  Inside the case 42, between the inflow port 43 and the outflow port 44, a cross-sectional circular hole shape having a predetermined inner diameter and axial length, that is, a hollow cylindrical measuring portion 56 is formed. The measuring portion 56 is formed by the sheet portion 50 that is an inner wall of the case 42. Further, a flange wall portion 58 is formed concentrically at the rear end portion of the rear case half 42b so as to protrude in a flange shape radially inward from the upstream side wall surface 52 of the case. The inlet 43 is formed by a circular hollow hole in the flange wall 58.

  The valve body 46 includes a columnar base shaft portion 60 and a tapered portion 62 that tapers from the base shaft portion 60 toward the tip portion. A flange portion 64 that protrudes radially outward is formed concentrically at the rear end (right end in FIG. 1) of the base shaft portion 60. Further, the tapered portion 62 has a diameter larger at the base end side (base shaft portion 60 side) than at the tip end side portion. Further, the base end side portion of the tapered portion 62 is formed in a columnar shape that is continuous with the base shaft portion 60 with the same outer diameter. Further, the tapered portion 62 is configured by, for example, a combination of a plurality of taper portions whose base end side portion is larger in diameter than the tip end portion and a plurality of straight portions having a constant outer diameter in the axial direction. Yes. The number of steps of the tapered portion, the taper angle, the number of steps of the straight portion, the length, and the like can be changed as appropriate.

  The tapered portion 62 of the valve body 46 is inserted into the measuring portion 56 of the case 42 from the inlet 43 side toward the outlet 44 side. Therefore, as the valve body 46 moves backward (moves to the right in FIG. 1), the clearance in the measuring portion 56, that is, the flow path cross-sectional area of the opening is increased. Conversely, as the valve body 46 moves forward (moves leftward in FIG. 1), the flow path cross-sectional area of the opening (gap) between the measuring portion 56 and the tapered portion 62 is reduced. The tapered portion 62 of the valve body 46 corresponds to the inside of the measuring portion 56 of the case 42 in the operating range R (see FIG. 6) between the last retracted position and the most advanced position of the valve body 46. Further, in the operating range R, the tip side portion of the valve body 46 is a range Ra corresponding to the WOT region of the engine 12. In the operating range R, the proximal end portion of the valve body 46 is a range Rc corresponding to the idle region of the engine 12. Further, in the operating range R, the range between the WOT range and the idle range is a range Rb corresponding to the partial range of the engine 12. Moreover, in FIG. 1, the valve body 46 is shown by the operating state corresponding to the WOT area | region of an engine. Moreover, in FIG. 4, the valve body 46 is shown by the operating state corresponding to the engine id region.

  As shown in FIG. 1, a spring 66 made of a compression coil spring is provided between the case 42 and the valve body 46 inside the case 42. The spring 66 is fitted to the shaft-like portion of the valve body 46. The spring 66 is interposed between the facing surfaces of the seat portion 50 of the case 42 and the flange portion 64 of the valve body 46. The spring 66 always urges the valve body 46 toward the inlet 43 side.

  In the PCV valve 40, since the negative pressure is not generated in the intake passage 27 while the engine 12 (see FIG. 7) is stopped, the valve body 46 is biased by the elasticity of the spring 66, so that the flange portion 64 becomes the flange wall. It will be in the state which approached the part 58 (refer the dashed-two dotted line 64 in FIG. 1). On the other hand, when the engine 12 is started, the negative pressure of the intake passage 27 is introduced into the inside of the case 42, that is, the gas passage 48 through the outlet 44, so that the valve body 46 is biased by the spring 66 by the action of the negative pressure. Against the outlet 44 side.

  Further, when the engine 12 is at a low load, the opening degree of the throttle valve 24a of the throttle body 24 (see FIG. 7) is reduced, and the negative pressure generated in the intake passage 27 is increased. For this reason, the valve body 46 is displaced to the outflow port 44 side by the negative pressure. Thereby, the range Rc (see FIG. 6) corresponding to the idle region of the engine 12 (see FIG. 7) corresponds to the measuring unit 56 of the case 42 (see FIG. 4). At this time, the flow passage cross-sectional area of the opening formed between the metering portion 56 and the tapered portion 62 becomes small, and the flow rate of the blow-by gas flowing through the PCV valve 40 becomes a small flow rate (see FIG. 5).

  Further, when the engine 12 is at a medium load, the opening degree of the throttle valve 24a of the throttle body 24 (see FIG. 7) increases, and the negative pressure generated in the intake passage 27 decreases. For this reason, the valve body 46 is displaced toward the inlet 43 by the biasing force of the spring 66. Thereby, a range Rb (see FIG. 6) corresponding to the partial area of the tapered portion 62 of the valve body 46 corresponds to the measuring portion 56 of the case 42. Therefore, as the valve body 46 is displaced, the flow passage cross-sectional area of the opening formed between the tapered portion 62 and the metering portion 56 of the valve body 46 gradually increases, and the blow-by gas flowing through the PCV valve 40 is increased. The flow rate increases in comparison with low load.

  Further, when the engine 12 is at a high load, the opening degree of the throttle valve 24a of the throttle body 24 (see FIG. 7) is further increased, and the negative pressure generated in the intake passage 27 is further reduced. For this reason, the valve body 46 is displaced toward the inlet 43 by the biasing force of the spring 66. Thereby, the range Ra (see FIG. 6) corresponding to the WOT region of the engine 12 (see FIG. 7) corresponds to the measuring unit 56 of the case 42 (see FIG. 1). For this reason, the flow path cross-sectional area of the opening formed between the tapered portion 62 of the valve body 46 and the metering portion 56 further increases, and the flow rate of the blow-by gas flowing through the PCV valve 40 is compared with that at the middle load. (See FIG. 2). In the WOT (Wide Open Throttle) region of the engine 12, there is a demand to increase the flow rate of blow-by gas.

  In this manner, the tapered portion 62 of the valve body 46 is inserted into the measuring portion 56 of the case 42, and the position of the tapered portion 62 in the reciprocating direction of the valve body 46 in the measuring portion 56 changes, whereby the measuring portion. The flow rate of blow-by gas flowing through the opening between 56 and the tapered portion 62 is measured (metered).

  Also, the tapered portion 62 of the valve body 46 has four rib-shaped ribs that project radially from the tapered portion 62 and extend in the axial direction and are slidable into contact with the measuring portion 56 of the case 42. A guide portion 70 is formed (see FIGS. 1 and 2). The base end side of the guide portion 70 extends to the flange portion 64 through the outer peripheral surface of the base shaft portion 60. The guide portion 70 has a wide portion 71 corresponding to the proximal end side of the tapered portion 62, a narrow portion 72 corresponding to the distal end side of the tapered portion 62, and a wide portion at the narrow portion side end portion of the wide portion 71. It has a gradually changing portion 71 a that gently connects the portion 71 and the narrow portion 72. The wide portion 71 is formed with a constant width 71W in the axial direction of the valve body 46 (see FIG. 5). The narrow portion 72 is formed with a constant width 72W in the axial direction of the valve body 46 (see FIG. 2). For example, the width 71W of the wide portion 71 is set to about 2.5 times the width 72W of the narrow portion 72. The ratio of the width 71W of the wide portion 71 and the width 72W of the narrow portion 72 can be changed as appropriate.

  As shown in FIG. 6, the wide portion 71 (including the gradually changing portion 71a) of the valve body 46 includes a range Rb corresponding to the partial region of the engine 12 (see FIG. 7) and a range Rc corresponding to the idle region (see FIG. 6). 6) (a length corresponding to the axial direction of the valve body 46). Further, a portion that extends from the wide portion 71 to the flange portion 64 through the outer peripheral surface of the base shaft portion 60 is referred to as an extension portion 73. The extension part 73 is formed with the same width 71 W as the wide part 71. Further, the narrow portion 72 is formed with a length exceeding a length corresponding to a range Ra (see FIG. 6) corresponding to the WOT region of the engine 12 (see FIG. 7) by a predetermined amount. Moreover, the four guide parts 70 are arrange | positioned at equal intervals in the circumferential direction of the valve body 46 (refer FIG.2 and FIG.5).

  The flange portion 64 of the valve body 46 is formed in a disc shape (see FIG. 3). On the outer peripheral surface of the flange portion 64, for example, four sliding surfaces 64a and four notch surfaces 64b are alternately formed in the circumferential direction. Each sliding surface 64a is capable of sliding contact with the passage wall surface 52 on the upstream side. For this reason, the sliding surface side end portion of the flange portion 64 corresponds to the four auxiliary guide portions 65. Further, the four auxiliary guide portions 65 are arranged at equal intervals in the circumferential direction of the valve body 46. Moreover, the opening part between the channel | path wall surface 52 and the flange part 64 of an upstream is a flow path through which blow-by gas flows.

  According to the PCV valve 40 described above (see FIG. 1), when the valve body 46 is reciprocated, the four guide portions 70 (specifically, the outer sides corresponding to the radial direction of the valve body 46) are measured with respect to the measuring portion 56 of the case 42. The valve body 46 is guided in the axial direction by the sliding contact of the auxiliary guide portion 65 (specifically, the sliding surface 64a) with the passage wall surface 52 on the upstream side of the case 42. The Thereby, the deflection of the valve body 46 in the radial direction can be prevented, and the operational stability of the valve body 46 can be improved.

  By the way, the guide part 70 of the valve body 46 is formed so that the width 72W on the distal end side is smaller than the width 71W on the proximal end side of the valve body 46 (see FIG. 6). For this reason, when the guide portion 70 on the proximal end side of the valve body 46 corresponds to the measuring portion 56 of the case 42, the width of the guide portion 70 on the proximal end side of the valve body 46, that is, the width 71W of the wide portion 71 is increased. Thereby, the abrasion resistance of the sliding part by the measurement part 56 and the guide part 70 can be improved (see FIGS. 4 and 5). Thus, when the guide portion 70 on the base end side of the valve body 46 corresponds to the measuring portion 56 of the case 42, that is, the wide portion in the range Rc (see FIG. 6) corresponding to the idle region of the engine 12 (see FIG. 7). When 71 corresponds to the metering portion 56 of the case 42, there is no need to increase the flow rate of the blow-by gas flowing through the opening between the metering portion 56 and the tapered portion 62, so that there is almost no problem.

Further, when the guide portion 70 on the distal end side of the valve body 46 corresponds to the measuring portion 56 of the case 42, that is, the narrow portion 72 in the range Ra (see FIG. 6) corresponding to the WOT region of the engine 12 (see FIG. 7). Corresponds to the metering portion 56 of the case 42, it is required to increase the flow rate of the blow-by gas. Therefore, by reducing the width 72W of the narrow portion 72 of the guide portion 70 on the distal end side of the valve body 46. The flow rate of blow-by gas can be increased (see FIGS. 1 and 2).
Therefore, it is possible to achieve both improvement in wear resistance of the sliding portion and increase in the flow rate of blow-by gas.

[Embodiment 2]
Embodiment 2 will be described. Since the embodiment after this embodiment changes the guide part 70 of the valve body 46 of the said Embodiment 1, the changed part is demonstrated and the overlapping description is abbreviate | omitted. FIG. 8 is a side view showing the valve body.
As shown in FIG. 8, in the present embodiment, among the guide portions 70 (see FIG. 6) of the valve body 46 of the first embodiment, the wide portion (reference numeral 74 is attached) of the engine 12 (see FIG. 7). It is formed with a length corresponding to the range Rc (see FIG. 6) corresponding to the idle region. Further, the narrow portion (reference numeral 75) is equivalent to a range Ra (see FIG. 6) corresponding to the WOT region of the engine 12 (see FIG. 7) and a range Rb (see FIG. 6) corresponding to the partial region. The length exceeds the predetermined amount. In FIG. 8, reference numeral 74 a denotes a gradually changing portion that gently connects the wide portion 74 and the narrow portion 75 at the end of the wide portion 74 on the narrow portion side.

[Embodiment 3]
A third embodiment will be described. In this embodiment, the guide portion 70 of the valve body 46 of the second embodiment is changed. FIG. 9 is a side view showing the valve body.
As shown in FIG. 9, in this embodiment, among the guide portions 70 (see FIG. 8) of the valve body 46 of the second embodiment, the wide portion (indicated by reference numeral 77) is that of the engine 12 (see FIG. 7). It is formed with a length corresponding to the range Rc (see FIG. 6) corresponding to the idle region. Further, the narrow portion (reference numeral 78) is formed with a length that exceeds a length corresponding to the range Ra (see FIG. 6) corresponding to the WOT region of the engine 12 (see FIG. 7) by a predetermined amount. . Further, the gradual change portion (reference numeral 79) is formed with a length corresponding to a range Rb (see FIG. 6) corresponding to the partial region of the engine 12 (see FIG. 7). Note that the gradual change portion 79 includes an end portion on the narrow portion side of the wide portion 77 (see the gradual change portion 74a in FIG. 8).

[Embodiment 4]
A fourth embodiment will be described. In the present embodiment, the guide portion 70 of the valve body 46 of the third embodiment is changed. FIG. 10 is a side view showing the valve body.
As shown in FIG. 10, this embodiment replaces the narrow portion 78 in the guide portion 70 (see FIG. 9) of the valve body 46 of the third embodiment, on the tip side continuous with the gradual change portion 79. A gradually changing portion 81 is formed.

[Embodiment 5]
Embodiment 5 will be described. In this embodiment, the guide portion 70 of the valve body 46 of the fourth embodiment is changed. FIG. 11 is a side view showing the valve body.
As shown in FIG. 11, in the present embodiment, in the guide portion 70 (see FIG. 10) of the valve body 46 of the fourth embodiment, instead of the wide portion 77, the base end side continuous to the gradually changing portion 79 is provided. A gradual change portion 83 is formed. Further, instead of the extension portion 73, an extended gradual change portion 84 continuous with the gradual change portion 83 on the proximal end side is formed.

[Embodiment 6]
Embodiment 6 will be described. In the present embodiment, the guide portion 70 of the valve body 46 of the first embodiment is changed. FIG. 12 is a side view showing the valve body.
As shown in FIG. 12, this embodiment omits the gradual change portion 71a in the guide portion 70 (see FIG. 6) of the valve body 46 of the first embodiment, and replaces the wide portion 71 and the narrow portion 72 with each other. It is connected in a stepped shape.

[Embodiment 7]
A seventh embodiment will be described. In the present embodiment, the guide portion 70 of the valve body 46 of the first embodiment is changed. FIG. 13 is a side view showing the valve body.
As shown in FIG. 13, the present embodiment is a portion of the wide portion 71 of the guide portion 70 (see FIG. 6) of the valve body 46 of the first embodiment (see FIG. 10) that does not correspond to the measuring portion 56, that is, the base shaft The extension part 73 on the part 60 is cut out.

  The present invention is not limited to the above-described embodiment, and modifications can be made without departing from the gist of the present invention. For example, the technical elements described in the above embodiments exhibit technical usefulness alone or in various combinations. The number of guide portions 70 is not limited to four and can be increased or decreased as appropriate. Further, the number of auxiliary guide portions 65 is not limited to four, and can be increased or decreased as appropriate. Further, the number of guide portions 70 and the number of auxiliary guide portions 65 may be different. The auxiliary guide portion 65 may be omitted. Further, the case 42 and / or the valve body 46 is not limited to resin and may be made of metal.

10 ... Blow-by gas reduction device 12 ... Engine (internal combustion engine)
40 ... PCV valve 42 ... case 43 ... inlet 44 ... outlet 46 ... valve element 56 ... metering part 62 ... tapered part 70 ... guide part 71 ... wide part 71a ... gradual change part 72 ... narrow part 74 ... wide part 74a ... Gradual change part 75 ... Narrow part 77 ... Wide part 78 ... Narrow part 79 ... Gradual change part 81 ... Gradual change part 83 ... Gradual change part

The present invention relates to a valve such as a PCV (Positive Crankcase Ventilation) valve used for a blow-by gas reduction device of an internal combustion engine (engine) in a vehicle such as an automobile.

According to the conventional example, the width 170W of the guide portion 170 of the valve body 146 is constant over the entire length. For this reason, the performance contrary to the improvement of the wear resistance of the sliding portion by the measuring portion 156 and the guide portion 170 and the increase in the flow rate of the blow-by gas flowing through the opening between the measuring portion 156 and the valve body 146. It was difficult to achieve both. 14 and 15 show a case where the width 170W of the guide portion 170 is set small. 16 and 17 show a case where the width 170W of the guide portion 170 is set large. Comparing the two, when the width 170W of the guide portion 170 is set small (see FIGS. 14 and 15), the flow passage cross-sectional area of the opening between the measuring portion 156 and the tapered portion 162 is wide. While the gas flow rate can be increased, the contact area of the guide portion 170 with respect to the measuring portion 156 is reduced, so that the wear resistance of the sliding portion is inevitably lowered. Further, when the width 170W of the guide portion 170 is set large (see FIGS. 16 and 17), the contact area of the guide portion 170 with the measuring portion 156 is widened, so that the wear resistance of the sliding portion can be improved. On the other hand, since the flow passage cross-sectional area of the opening between the metering portion 156 and the valve body 146 is reduced, the flow rate of the blow-by gas must be reduced. Therefore, there is a problem that it is impossible to achieve both improvement in wear resistance of the sliding portion and increase in the flow rate of blow-by gas. In Patent Document 1, there is a problem similar to that of the conventional example. In the WOT (Wide Open Throttle) region of the engine, there is a demand to increase the flow rate of blow-by gas.
The problem to be solved by the present invention is to achieve both improvement in wear resistance of the sliding portion and increase in the flow rate of gas .

Claims (1)

A valve body is accommodated in a case having an inlet and an outlet so as to be capable of reciprocating,
A measuring section having a circular cross section is formed by the inner wall of the case,
The valve body has a proximal end portion whose diameter is expanded more than a distal end portion by a tapered portion formed on the outer periphery of the valve body,
By inserting the tip side portion of the valve body into the measuring portion of the case and changing the position of the tapered portion in the reciprocating direction, the gap between the measuring portion and the tapered portion is passed. A PCV valve for metering blow-by gas flowing from the inlet to the outlet,
The valve body is formed with a plurality of rib-shaped guide portions protruding radially from the tapered portion and extending in the axial direction and capable of sliding contact with the measuring portion of the case,
The PCV valve, wherein the guide portion is formed to have a width on a distal end side smaller than a width on a proximal end side of the valve body.

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