JPS6321777Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fitting type connection mechanism, and in particular to a negative pressure diaphragm device that connects each rotary valve to simultaneously open the rotary valves provided for each helical intake port of an internal combustion engine. This invention relates to a fitting type connection mechanism provided between the two.

A helical intake port typically consists of a spiral formed around the intake valve and an inlet passageway tangentially connected to the spiral and extending generally straight. If you try to use such a helical intake port to generate a strong swirling flow in the combustion chamber of the engine during low-speed, low-load engine operation with a small amount of intake air, the shape of the intake port will have a large flow resistance. There is a problem in that the filling efficiency decreases when the engine is operated at high speed and under high load with a large amount of air. In order to solve this problem, a branch path is formed in the cylinder head that branches from the helical intake port inlet passage and connects to the spiral end of the helical intake port spiral section, and an actuator is installed in the branch path. The main helical intake port flow path control device is a helical intake port flow path control device that is equipped with a normally-closed on-off valve that is operated by the engine, and operates an actuator to open the on-off valve when the amount of engine intake air becomes larger than a predetermined amount. Already proposed by the applicant. In this helical type intake port, when the engine is operated at high speed and under high load with a large amount of engine intake air, part of the intake air sent into the helical type intake port inlet passage is sent into the helical type intake port spiral part through the branch passage. The flow resistance to the intake air flow is reduced and thus a high filling efficiency can be obtained. As mentioned above, in this helical intake port, an on-off valve is operated by an actuator, and this on-off valve is provided for each helical intake port of each cylinder and is controlled simultaneously by the actuator. . However, the connection mechanism between the actuator and each on-off valve in this helical intake port only shows the basic operating principle, and therefore, in order to put this connection mechanism into practical use, it is necessary to reduce assembly man-hours, ease of manufacturing, and ensure reliable operation. However, various problems remain in terms of manufacturing costs.

The object of the present invention is to provide a snap-on connection mechanism with a novel structure suitable for practical use.

below. The present invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, 1 is a cylinder block, 2 is a piston that reciprocates within cylinder block 1, 3 is a cylinder head fixed on cylinder block 1, and 4 is a link between piston 2 and cylinder head 3. 5 is an intake valve,
6 is a helical intake port formed in the cylinder head 3, 7 is an exhaust valve, and 8 is a cylinder head 3.
Exhaust ports formed therein are shown respectively. Although not shown in the figure, an ignition plug is disposed within the combustion chamber 4.

3 to 5 schematically show the shape of the helical intake port 6 of FIG. 2. This helical intake port 6 has a flow path axis a as shown in FIG.
It is composed of a slightly curved inlet passage part A and a spiral part B formed around the valve axis of the intake valve 5, and the inlet passage part A is tangentially connected to the spiral part B. As shown in FIGS. 3, 4, and 7, the side wall surface 9 of the inlet passage A near the spiral axis b
The upper side wall surface 9a is formed as an inclined surface facing downward, and the width of this inclined surface 9a becomes wider as it approaches the spiral portion B. As shown in the figure, the entire side wall surface 9 is formed into a downwardly oriented inclined surface 9a. The upper half of the side wall surface 9 is smoothly connected to the peripheral wall surface of a cylindrical projection 11 formed on the upper wall surface of the intake port around the intake valve guide 10 (FIG. 2).
The lower half of the spiral portion B is connected to the side wall surface 12 of the spiral portion B at the spiral end portion C of the spiral portion B.

On the other hand, as shown in FIGS. 1 to 5, a branch passage 14 having a substantially uniform cross section is formed in the cylinder head 3, branching from the inlet passage part A, and this branch passage 14 is connected to the spiral terminal part C. Connected. Branch road 14
An inlet opening 15 is formed on the side wall surface 9 in the vicinity of the inlet opening of the inlet passage section A, and an outlet opening 16 of the branch passage 14 is formed at the upper end of the side wall surface 12 at the spiral end C. Furthermore, an on-off valve insertion hole 17 is provided in the cylinder head 3 and extends through the branch passage 14.
are drilled, and rotary valves 18 constituting the on-off valves are inserted into the on-off valve insertion holes 17, respectively. The rotary valve 18 is disposed within the branch passage 14 and includes a thin plate-shaped valve body 19 as shown in FIG. 9, and a valve stem 20 integrally formed with the valve body 19. It is rotatably supported by a guide sleeve 21 fitted into the on-off valve insertion hole 17. The valve stem 20 projects upward from the top surface of the guide sleeve 21, and an arm 22 is fixed to the projecting end.

Referring to FIG. 10, the tip of the arm 22 fixed to the upper end of each rotary valve 18 is connected via a connecting rod 43 to a control rod 42 fixed to a diaphragm 41 of a negative pressure diaphragm device 40. The negative pressure diaphragm device 40 has a negative pressure chamber 44 isolated from the atmosphere by a diaphragm 41, and a compression spring 45 for pressing the diaphragm is inserted into the negative pressure chamber 44. An intake manifold 47 is attached to the cylinder head 3 and includes a compound type carburetor 46 consisting of a primary carburetor 46a and a secondary carburetor 46b. The negative pressure chamber 44 is connected on the one hand to a negative pressure conduit 48 and to the negative pressure port 4 of the negative pressure control device 70.
9, connected to the intake manifold 47 via a check valve 50 and a negative pressure conduit 51, and on the other hand connected to the atmosphere via an atmospheric port 52, an atmospheric pressure chamber 54 of an atmospheric release valve 53, an atmospheric passage 55 and an air filter 56; Ru. The atmosphere release valve 53 includes a diaphragm 57,
A negative pressure chamber 58 isolated from the atmospheric pressure chamber 54 by a diaphragm 57, and a valve body 59 fixed to the diaphragm 57 to control opening and closing of the atmospheric port 52.
and a compression spring 60 for pressing the diaphragm,
The negative pressure chamber 58 is connected to a negative pressure port 61 that opens to the bench lily portion of the primary side carburetor 46a and the secondary side carburetor 4.
It is connected via a negative pressure conduit 63 to a negative pressure port 62 that opens to the bench lily portion of 6b.

The vaporizer 46 is a commonly used vaporizer.
When the downstream throttle valve 64 opens a predetermined opening degree or more, the secondary throttle valve 65 opens, and if the primary throttle valve 64 fully opens, the secondary throttle valve 65 opens.
5 is also fully opened. The negative pressure applied within the negative pressure conduit 63 connected to both negative pressure ports 61 and 62 increases as the amount of intake air supplied into the engine cylinder increases. When the pressure becomes higher than a predetermined constant pressure, that is, when the engine is operated at high speed and high load, the diaphragm 57 of the atmosphere release valve 53 moves downward against the compression spring 60, and as a result, the valve body 59 closes to the atmosphere port 52. The valve is opened to expose the negative pressure chamber 44 of the negative pressure diaphragm device 40 to the atmosphere. At this time, the diaphragm 41 is moved away from the negative pressure chamber 44 by the spring force of the compression spring 45, and as a result, the rotary valve 18 is rotated and the branch passage 14 is fully opened. On the other hand, when the opening degree of the primary throttle valve 64 is small, the negative pressure conduit 6
Because the negative pressure applied inside 3 is small, the atmosphere release valve 53
The diaphragm 57 is moved upward by the spring force of the compression spring 60, and the valve body 59 closes the atmospheric port 52. Furthermore, in this way, the primary side throttle valve 64
When the opening degree of the intake manifold 47 is small, a large negative pressure is generated within the intake manifold 47. The check valve 50 opens when the negative pressure in the intake manifold 47 becomes greater than the negative pressure in the negative pressure chamber 44 of the negative pressure diaphragm device 40 , and the negative pressure in the intake manifold 47 becomes larger than the negative pressure in the negative pressure chamber 44 .
The negative pressure in the negative pressure chamber 44 is maintained at the maximum negative pressure generated in the intake manifold 47 as long as the atmospheric opening/closing valve 53 is closed. When negative pressure is applied in the negative pressure chamber 44, the diaphragm 41 moves toward the negative pressure chamber 44 against the pressure spring 45, and as a result, the rotary valve 18 is rotated and the branch passage 14 is closed. Therefore, when the engine is operating at low speed and low load, the branch passage 14 is closed by the rotary valve 18.

As mentioned above, the rotary valve 18 shuts off the branch passage 14 when the engine is operating at low speed and low load with a small amount of intake air. At this time, the air-fuel mixture sent into the inlet passage part A descends inside the swirl part B while swirling along the upper wall surface 13 of the swirl part B, and then flows into the combustion chamber 4 while swirling. A strong swirling flow is generated inside. On the other hand, when the engine is operated at high speed and under high load with a large amount of intake air, the rotary valve 18 opens, so that part of the air-fuel mixture sent into the inlet passage A flows into the volute part B via the branch passage 14 with low flow resistance. sent to. This air-fuel mixture flows into the swirl part B from the inlet passage part A and collides head-on with the air-mixture flow flowing along the upper wall surface 13 of the swirl part B.
As a result, the air mixture flowing along the upper wall surface 13 of the swirl portion is decelerated and the swirling flow is weakened.
In this manner, when the engine is operated at high speed and under high load, the rotary valve 18 opens, which not only increases the overall flow path area but also weakens the swirling flow, thereby ensuring high filling efficiency.

As shown in FIG. 10, the arm 22 of the rotary valve 18 of each cylinder is connected to a control rod 42 of a negative pressure diaphragm 40 via a connecting rod 43. The connecting rod 43 consists of a single rod integrally formed, and as shown in FIG. 11, a plurality of arm connecting portions 66 are provided on the connecting rod 43 corresponding to each arm 22. As shown in FIG. These arm connections have a similar structure and therefore one of these arm connections 66 will be described with reference to FIGS. 12-17.

Referring to FIG. 12, the connecting rod 43 has an enlarged portion 80 onto which a cylindrical clip 81 is fitted. On the other hand, a connecting member 82 is fixed to the tip of the arm 22.
2 has a substantially spherical head 83 and an inverted conical portion 84 extending downward from the bottom of the head 83. 13th
As shown in FIGS. 15 to 15, the clip 81 has a protrusion 84 projecting inward at the center of its head, and a dividing slit 85 extending in the longitudinal direction of the connecting rod 43 is formed at the lower end of the clip 81. be done.
The divided slit 85 has an enlarged circular opening 86 having a substantially circular shape in its center, and this enlarged circular opening 8
A pair of guide walls 87 and 88 extending downward and facing each other are formed on the outer wall surface of the clip 81 around the clip 81 . Each of these guide walls 87, 88 has a cylindrical shape, and skirt portions 89, 90 that expand outward are formed at the lower ends of each guide wall 87, 88. As can be seen from FIGS. 14 and 15, these skirt portions 89 and 90 have dividing slits 85.
The dividing slit 85 extends over almost the entire length on both sides of the dividing slit 85. Furthermore, as shown in FIGS. 14 and 16, each guide wall 87, 88 and the skirt portion 8
Circular holes 91 and 92 are provided at the boundaries with 9 and 90, respectively.
is formed.

FIG. 16 shows the state in which the head 83 of the connecting portion 82 of the arm 22 is fitted and fixed onto the enlarged portion 80 of the connecting rod 43 using the clip 81. As can be seen from FIG. 16, a substantially spherical groove 93 is formed in the enlarged portion 80 of the connecting rod 43, and the head 83 of the arm connecting portion 82 is fitted into this groove 93. Further, a concave groove 93 is provided in the connecting rod enlarged portion 80.
A through hole 94 is formed extending upward from the top of the
The protrusion 84 of the clip 81 engages with this through hole 94.

To attach the connecting rod 43 to the connecting part 82 of each arm 22, first fit the clip 81 into the enlarged part 80 of the connecting rod 43 as shown in FIG. through hole 9
4 with the protrusion 84 of the clip 81. Next, as shown in FIG. 17, the opening 9 of the clip 81 is
Insert the tip of the jig 95 into 1 and 92, and
While expanding the guide walls 87 and 88 outward in the direction of arrow A, insert the head 83 of the arm connecting portion 82 between the guide walls 87 and 88, and then insert the head 83 between the guide walls 87 and 88 as shown in FIG. The connecting rod fits into the concave groove 93 of the enlarged portion 80. When the head 83 is fitted into the groove 93, the guide walls 87, 8 are inserted as shown in FIG.
8 returns to its original position, thereby connecting the arm connecting portion 82 and the connecting rod 43.

As is clear from the above description, according to the present invention, the connecting rod can be easily attached to each arm connecting portion by using a jig. Therefore, there is an advantage that the number of man-hours required for assembling the connecting rod can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an internal combustion engine according to the present invention, Fig. 2 is a plan view of an internal combustion engine according to the present invention;
The figure is a cross-sectional view taken along the - line in Figure 1.
The figure is a perspective view showing the shape of a helical intake port.
Fig. 4 is a plan view of Fig. 3, Fig. 5 is a side sectional view taken along the branch road in Fig. 3, Fig. 6 is a sectional view taken along the - line in Fig. 4, and Fig. 7. is a sectional view taken along the - line in Fig. 4, Fig. 8 is a sectional view taken along the - line in Fig. 4, Fig. 9 is a perspective view of the rotary valve, and Fig. 10 is a sectional view of the flow path control device. Overall view, Figure 11 is a plan view of the connecting rod, Figure 12 is a perspective view of the connecting rod with the clip fitted and the arm connecting part, Figure 13 is a side view of the clip, and Figure 14 is the same as Figure 13. 15 is a bottom view of FIG. 14, FIG. 16 is a cross-sectional view showing the arm connecting portion connected to the connecting rod, and FIG. 17 is a cross-sectional view for explaining how to use the jig. be. 6... Helical intake port, 14... Branch path, 18... Rotary valve, 22... Arm, 40
... Negative pressure diaphragm device, 43 ... Connection rod, 81 ... Clip, 83 ... Head, 85 ...
Divided slit, 86...Enlarged circular opening, 87,8
8... Guide wall, 91, 92... Opening.

Claims (1)

[Scope of utility model registration request] A substantially spherical groove is formed on the outer wall surface of the drive shaft, a cylindrical clip is fitted onto the shaft so as to cover the groove, and the clip extends in the longitudinal direction of the shaft on the outer peripheral wall surface of the clip. A dividing slit is formed, and an enlarged circular opening aligned with the groove is formed in the center of the dividing slit, and a pair of guide walls protrudes outward on the outer wall surface of the clip around the enlarged circular opening and faces each other. The substantially spherical head of the driven member to be connected to the drive shaft is fitted into the groove through the enlarged circular opening while pushing the guide wall to the left and right. A fitting type connection mechanism with holes drilled into each of the holes into which a jig can be inserted to separate the guide walls.