JPS6231620Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flow path control device for a helical intake port of an internal combustion engine, and particularly relates to a seal structure for a bypass valve device provided in a bypass passage of a helical intake port. It is.

[Prior Art] In order to improve the combustion characteristics of an internal combustion engine, and thereby improve fuel efficiency and output performance, a helical intake port is sometimes used as an intake port. The helical intake port improves combustion performance by generating swirl in the combustion chamber in the engine's low-speed, low-load range. However, in the high-speed, high-load range, the swirling flow creates resistance and reduces charging efficiency, so a bypass passage is required. By arranging them in parallel, it is possible to prevent the filling efficiency from decreasing. In this case, an on-off valve is provided in the bypass passage, and the bypass passage is opened and closed according to the operating conditions of the engine. (For example, as prior applications, there are Japanese Patent Application No. 56-51149 and Japanese Patent Application No. 56-120634.) [Problems to be solved by the invention] The on-off valve has its valve body inserted into the bypass passage, The shaft passes through the cylinder head and protrudes above the cylinder head, and the protrusion is connected to the opening/closing actuator via a link mechanism.
It is opened and closed by an actuator. However, since the upper part of the cylinder head where the opening/closing valve shaft and guide protrude are lubricating oil reservoirs, care must be taken to prevent oil from leaking into the intake system through the opening/closing valve penetration and causing an abnormal increase in oil consumption. , cylinder head penetrations of on-off valves must be well sealed. In particular, if the sealing material that performs the sealing function of the penetration part is exposed to tools such as socket trenches when assembling the bypass valve, or if an excessive load is applied during engine operation, the sealing material may tilt and lose its sealing function. Alternatively, the sealing material must be sufficiently protected so as not to damage the sealing material and destroy its sealing properties.

The purpose of this invention is to ensure the sealing performance of the oil seal of the bypass valve and to prevent oil leakage.

[Means for solving the problem] In order to achieve this object, a flow path control device for a helical intake port according to the present invention rotates using a bypass valve that opens and closes a bypass passage of a helical intake port as a guide. In a flow path control device for a helical intake port in which the guide is mounted on the cylinder head within the cylinder head cover, a rubber material and the rubber material are covered between the shaft of the bypass valve and the guide. An oil seal consisting of a metal ring is provided, and the lower end of the metal ring is abutted against the upper end surface of the guide, and an oil seal is provided between the upper part of the position regulating ring attached to the shaft of the bypass valve and the oil seal. It consists of a helical intake port flow path control device characterized by providing a gap D larger than the maximum clearance d between the bypass valve and the guide in the axial direction.

[Function] Due to the configuration in which the metal ring of this oil seal butts against the upper wall surface of the guide, the oil seal will not tilt even if a tool such as a socket trench hits it during assembly, and the seal function will not deteriorate due to tilting. does not occur. In addition, due to the gap D above the ring (E-ring), even if the bypass valve moves a small amount in the axial direction, the E-ring will not hit the oil seal and cause the oil seal to be unreasonably deformed, and the sealing function due to deformation will not be affected. No degradation and therefore no damage occurs. Therefore, the sealing performance of the oil is maintained soundly.

[Embodiments] Hereinafter, preferred embodiments of the helical intake port flow path control device of the present invention will be described with reference to the drawings.

1 to 3 show the entire system of a flow path control device for a helical intake port.
In the figure, 1 is the cylinder block, 2 is the piston, and 3 is the cylinder block.
is the cylinder head, 4 is the combustion chamber, 5 is the intake valve, 6
is a helical intake port. The helical intake port 6 consists of an inlet passage part 6a extending almost straight and a spiral part 6b downstream of the inlet passage part 6a.
a and the terminal end of the spiral portion 6b are connected by a bypass passage 7. The bypass passage 7 is provided with a bypass valve 8 that opens and closes the bypass passage 7. The bypass valve 8 is connected via a linkage 9 to a diaphragm device 10 as an actuator. A negative pressure chamber 12 defined by a diaphragm 11 in the diaphragm device 10 is switchably connected via a negative pressure control device 13 to an intake manifold 14 or to the atmosphere. This switching is performed by the negative pressure chamber 1 formed in the negative pressure control device 13.
5 is communicated with the negative pressure ports 17 and 18 of the bench lily portion of the compound type vaporizer 16, and the diaphragm 19 and valve body 20 are operated to open and close the atmospheric port 21. The opening and closing direction of the bypass valve 8 of the diaphragm device 10 by the negative pressure control device 13 is such that the bypass passage 7 is closed when the engine is in a low speed and low load range, and the bypass passage 7 is closed when the engine is in a high speed and high load range. It is set in the direction of opening.

4 and 5 show the bypass valve 8 and its surrounding structure in detail. As shown in the figure, the bypass valve 8 has an integral structure of a valve body 8a and a shaft portion 8b. The valve 8 has its shaft portion 8
It is rotatably supported by the guide 22 at b. Then, the guide 22 is located at its lower part (spigot part) 23.
It is fitted into the hole (spigot hole) 24 of the cylinder head 3, and the male threaded part 25 in the center is inserted into the cylinder head 3.
The cylinder head 3 is attached to the cylinder head 3 by being screwed into the female threaded portion 26 of the cylinder head 3. The upper part of the guide 22 protrudes above the cylinder head 3, and a hexagonal nut part 27 is integrally formed in this part, and a tool such as a socket trench is engaged with this part to attach the guide 22 to the cylinder head 3. It is now possible to tighten it. The guide 22 has a cylindrical part 28 whose diameter is reduced above the hexagonal nut part 27, and this cylindrical part 28 has an outer diameter which is further reduced in diameter at a position spaced downward from the upper end surface 29. An annular groove 30 is formed. On the other hand, the upper end surface 29 of the guide 22 is attached to the shaft portion 8b of the valve 8.
An annular groove 31 is provided at a position corresponding to , and an E-ring 32 is fitted into this groove 31. This E-ring 32 and a large-diameter disc-shaped valve body mounting portion 33 at the lower end of the shaft sandwich the upper and lower ends of the guide 22 with a slight clearance d. One end of a plate-shaped arm 34 extending in a direction perpendicular to the shaft portion 8b is attached to the upper end of the shaft portion 8b to prevent free rotation, and a ball joint 35 is attached to the other end of the arm 34. It is mounted so that it can rotate around its axis. By connecting this ball joint 35 to the diaphragm device 10 via the link device 9, the movement of the diaphragm device 10 is transmitted to the bypass valve 8.

An oil seal 36 is provided between the bypass valve 8 and the guide 22. The oil seal 36 has a rubber material 39 having a constricted upper part 37 and a protruding part 38 toward the inner periphery at the lower end, and a metal ring 40 is integrally provided on the outer periphery of the rubber material 39 from the center downward. There is. The lower end of the metal ring 40 extends slightly below the lower end of the rubber member 39. Upper part 3 of rubber material 39
A Teflon film 41 is baked on the inner periphery of the upper part 37, and an annular spring 42 is fitted on the outer periphery of the upper part 37 to increase the binding force.

The oil seal 36 is fitted on the outer periphery of the upper end of the shaft portion 8 b of the bypass valve 8 and on the upper part of the guide 22 . is pressed against the upper end surface of. Further, the protrusion 3 protrudes toward the inner circumferential side of the lower end of the rubber material 39.
8 enters and engages with the annular groove 30 at the upper end of the guide 22. As a result, the oil seal 36
The oil seal 36 does not float upward from the guide 22, and the lower end of the oil seal 36 is firmly attached to the guide 22.

Further, the oil seal 36 is
With its lower end abutting the guide 22, insert the stepped portion so that a gap D is formed between the E-ring 32 attached to the valve shaft portion 8b and the oil seal inner peripheral stepped portion 43. The height between the metal ring 43 and the lower end of the metal ring 40 is determined. This gap D is set to be larger than the maximum clearance d between the lower end surface of the guide 22 and the upper surface of the valve body mounting portion 33. That is, although the valve 8 can move by a maximum distance d in the axial direction, a gap D is formed that is large enough not to interfere with the oil seal 36 even if the E ring 32 moves together with the valve 8.

An upper portion 37 of the oil seal 36 is slidably pressed against the outer periphery of the shaft portion 8b of the bypass valve 8. In this case, the annular spring 42 has increased pressure. The sliding surface of the oil seal 36 with the valve shaft portion 8b is a Teflon film 41. Note that 44 is a shield that covers and protects the oil seal 36 from above. Further, oil accumulates above the cylinder head 3.

Next, the operation of the above device will be explained. First, when the engine is running at low speed and under low load, the negative pressure in the vent lily is small and the negative pressure control device 13 closes the atmospheric port 21, and the high negative pressure of the intake manifold 14 is introduced into the negative pressure chamber 12 of the diaphragm device 10. Link device 9
is pulled, the bypass valve 8 is rotated to the closing side, the bypass passage 7 is closed, and the intake air is allowed to flow only into the helical intake port 6 to generate a strong swirling flow, and the swirl in the combustion chamber 4 causes combustion. Improve your sexuality. Also, when the engine is at high speed and under high load, the negative pressure control device 13 opens the atmospheric port 21, opens the negative pressure chamber 12 of the diaphragm device 10 to the atmosphere, pushes the link device 9, and pushes the bypass valve 8 to the open side. to open the bypass passage 7 and open the bypass passage 7.
This also allows intake air to flow through the engine to increase charging efficiency and prevent a drop in output.

In this way, the bypass valve 8 is connected to the linkage device 9
, the bypass valve 8 rotates within the guide 22 and also tries to move in the axial direction. In this case, even if the bypass valve 8 moves in the axial direction and the E-ring 32 attached to the shaft portion 8b moves in the vertical direction, a gap D larger than the maximum clearance d is left above the E-ring 32. Therefore, the E-ring 32 will not press the oil seal 36, and the oil seal 36 will not be deformed and its sealing function will not be inhibited or damaged. That is, the oil seal 36 is prevented from causing the above-mentioned problems throughout the engine operation.

In addition, even when the engine is not running and the valve is installed, the sealing function of the oil seal 36 may be obstructed by a tool such as a socket trench hitting the metal ring 40 of the oil seal 36 when tightening the guide 22 and causing the oil seal 36 to tilt. However, since a single diaphragm device and link drive four bypass valves (four cylinders) at the same time, the binding force of the oil seal cannot be increased in order to obtain smooth operation, and therefore a slight inclination is required. However, oil leakage occurs)
In the present invention, the lower end of the oil seal 36 is connected to the guide 22.
Even if the socket trench hits the oil seal 36, it will not tilt, and the sealing performance will not be impaired during assembly.

[Effect of the invention] As described above, when using the helical intake port flow path control device of the invention, the metal ring of the oil seal is brought into contact with the upper wall surface of the guide, so that
Even if a tool such as a socket trench hits the oil seal, the oil seal will not tilt, and since a gap D larger than d is provided above the ring, even if the bypass valve moves upward, the oil seal and E-ring will not tilt. Since there is no interference, the sealing performance of the oil seal can be ensured, and the effect of preventing oil leakage and suppressing an increase in oil consumption can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the helical intake port flow path control device of the present invention near the bypass valve, Fig. 2 is a schematic plan view showing only the intake port in Fig. 1, and Fig. 3 is the main part of the present invention. A system diagram of the actuator side of the invented helical intake port flow path control device, Fig. 4 is a sectional view of the bypass valve and its immediate vicinity, Fig. 5 is a front view of the bypass valve of Fig. 4,
It is. 3... Cylinder head, 6... Helical intake port, 7... Bypass passage, 8... Bypass valve, 8a... Valve body, 8b... Shaft portion, 22... Guide, 32... Ring (for example, E ring), 3
6...Oil seal, 38...Protrusion, 40...
Metal ring, 43...Oil seal inner peripheral step, D...
Gap between the top of the ring and the inner step of the oil seal, d
...Maximum clearance between the lower end of the guide and the upper surface of the valve body mounting part.

Claims (1)

[Claim for Utility Model Registration] A bypass valve 8 for opening and closing the bypass passage 7 of the helical intake port 6 is rotatably supported on a guide 22, and the guide 22 is mounted on the cylinder head 3 within the cylinder head cover. In a flow path control device for a helical intake port, an oil seal 36 consisting of a rubber material 39 and a metal ring 40 covering the rubber material is provided between the shaft portion 8b of the bypass valve 8 and the guide 22, and the metal ring The lower end of the guide 22 is in contact with the upper end of the guide 22, and the bypass valve 8 and the guide in the axial direction are arranged between the upper part of the position regulating ring 32 attached to the shaft part 8b of the bypass valve and the oil seal 36. 2
A flow path control device for a helical intake port, characterized in that a gap D larger than a maximum clearance d between the two is provided.