JP6152695B2 - Valve mechanism of internal combustion engine - Google Patents

Description

  The present invention includes a retaining member that engages with an end portion of a valve shaft, and a spring receiving member that is biased by a valve spring, and the spring receiving member and the valve are configured to move together via the retaining member. The present invention relates to a valve mechanism of an internal combustion engine.

  The engine is provided with an intake valve and an exhaust valve (hereinafter collectively referred to as a valve), and these valves are moved by a valve mechanism to control intake and exhaust efficiently. As shown in FIG. 8, the valve operating mechanism 1 </ b> X includes a cotter (a retaining member) 3 that engages with an end portion of the shaft of the valve 2, a spring seat (a spring receiving member) 5 that is biased by a valve spring 4, and The valve 2 and the spring seat 5 are configured to move together via the cotter 3.

  When one end of the valve 2 is pushed by a cam or actuator (not shown), the valve 2 is lowered, and intake and exhaust are performed. Then, when the operation of the cam or actuator is lost, the spring seat 5 is pushed by the urging force of the valve spring 4 to return the valve 2 to its original position.

  While the above operation is repeated while the engine is in operation, there may be a so-called surging phenomenon in which the operation of the valve spring 4 cannot catch up with the operation of the valve 2 due to the high speed rotation of the engine.

  As shown in FIG. 8A, when the surging phenomenon occurs, the speed at which the spring seat 5 biased by the valve spring 4 moves upward is slower than the speed at which the valve 2 moves upward, resulting in a cotter. 3 and the spring seat 5 are disengaged, and the spring seat 5 is positioned below the cotter 3. At this time, when a normal split type cotter is used as the cotter 3, the engagement between the cotter 3 and the end of the shaft of the valve 2 is disengaged as shown in FIG. It will fall off from the end of the shaft of the valve 2.

  Thus, since the fitting of the cotter 3 and the spring seat 5 is separated and the cotter 3 is further separated from the valve 2, the valve 2 is dropped into the combustion chamber of the cylinder, and in the worst case, the piston can be destroyed. There is sex.

  Several devices for solving the above problems have been proposed. One of them is a truncated cone-like structure that presses the cotter inward and the spring seat outward, between the cotter and the spring seat. There is an apparatus provided with a coil spring (see, for example, Patent Document 1).

  This apparatus prevents the cotter and the spring sheet from separating by the winding plate spring pressing the cotter inward and the spring seat outward. In addition, even if the spring seat is displaced slightly downward, within the range where the lower edge of the coil spring is in pressure contact with the cylindrical surface of the spring seat, if the surging phenomenon stops, it will return to normal and the cotter and spring seat will be separated. Is prevented.

  However, in consideration of the nature of the coil spring, the coil spring always presses the spring seat outward. Therefore, for example, when the coil spring is in a state as shown in FIG. The pressure from the sheet 5 is applied. In such a state, the winding spring may be deformed or damaged. Then, the winding plate spring and the spring seat are separated from each other, or the cotter and the winding plate spring are separated from each other, so that the cotter is dropped and the valve is dropped into the combustion chamber of the cylinder.

  Further, in the above-described apparatus, the spring seat is located below the cotter and the cotter and the spring seat are separated as shown in FIG. In this case, it is possible to prevent the cotter from falling off from the end of the valve shaft by the coil spring, but the valve cannot perform the opening / closing movement, and thus cannot perform its original role.

Japanese Utility Model Publication No. 51-101410

  The present invention has been made in view of the above-described problems, and the problem is that a pressing force can be applied to the retaining member so that the retaining member does not fall off the end of the shaft of the valve, and the operation of the valve It is another object of the present invention to provide a valve operating mechanism for an internal combustion engine that can prevent a retaining member from separating from a spring receiving member even if a surging phenomenon occurs in which the operation of the valve spring cannot catch up.

In order to solve the above problems, a valve operating mechanism for an internal combustion engine according to the present invention includes a retaining member that engages with an end of a shaft of a valve, and a spring receiving member that is urged by a valve spring. In the valve operating mechanism of the internal combustion engine configured so that the valve moves integrally through the retaining member, the central portion has a fitting hole, and the central portion warps convexly upward. a spring having a fitting hole in the center, provided with a disc spring whose central portion is warped in a convex upward, the disc spring, the inner circumferential surface of the fitting hole of the retaining member fitted with the outer peripheral surface, the outer peripheral surface of the disc spring is the inner peripheral surface and the fitting of the spring receiving member, the deformation of the warp of the disc spring, the inner circumferential surface of the fitting hole
Presses the inner circumferential surface outward of the outer peripheral surface of the retaining pressing to Rutotomoni the disc springs inwardly the outer peripheral surface of the member is the spring receiving member, further, the said stop member and said valve of said disc spring warpage characterized by being movable in a vertical direction with respect to the spring receiving member to the extent that deformation.

  The term “within a predetermined range” as used herein means that the elastic force of the disc spring is within the range where the effect is exerted. The range in which the elastic force of the disc spring exerts an effect is a range from a state where the disc spring is warped to a state where the disc spring is flattened, and within that range, the retaining member is pressed inward, and the spring The receiving member is pressed outward. Therefore, the valve integrated with the disc spring by the retaining member is in a movable state between a position when the disc spring is warped and a position where the disc spring is flattened.

  According to this configuration, by providing the disc spring between the spring receiving member and the retaining member, the engagement between the retaining member and the shaft step portion of the valve is maintained within the range where the elastic force of the disc spring exerts an effect. The separation between the retaining member and the disc spring and the separation between the retaining member and the spring receiving member can be prevented.

  As a result, the engagement between the retaining member and the shaft end of the valve is disengaged, and the retaining member falls off from the shaft end of the valve, and the valve can be prevented from falling off.

  For example, normally, since the spring receiving member is urged from the valve spring, an upward force is applied to the disc spring, the disc spring is deformed so as to be flat, and the valve is opened and closed. However, if a surging phenomenon occurs in which the valve spring does not catch up with the opening and closing movement of the valve, even if the retaining member moves away from the spring receiving member, until the disc spring returns to the warped state, Since the retaining member and the disc spring are kept in a fitted state, even if the surging phenomenon occurs, separation between the retaining member and the spring receiving member can be prevented as long as it is within the above-described range.

  In addition, since the valve is movable within the above-described range, even if the spring receiving member deviates from the normal state or falls off, as long as the retaining member and the disc spring are fitted, the valve Can serve as This means that the fail-safe for the height of the disc spring warp works.

  In the valve mechanism of the internal combustion engine, if the disc spring is provided with a separation preventing member so that the spring receiving member and the disc spring are not separated, the separation preventing member causes the spring receiving member and the disc spring to be separated from each other. Separation can be prevented.

  For example, when the disc spring is fitted in a wedge shape with the spring receiving member, the disc spring is separated from the spring receiving member even if a surging phenomenon occurs by providing a tongue-shaped projection as a separation preventing member on the disc spring. Can be prevented.

  In addition, in the valve mechanism of the internal combustion engine, when the outer peripheral surface of the retaining member and the inner peripheral surface of the disc spring are configured as a separation preventing structure that fixes the retaining member and the disc spring so as not to be separated from each other, Since the outer peripheral surface of the retaining member and the inner peripheral surface of the disc spring are fixed, separation of the retaining member and the disc spring can be prevented.

  For example, the separation preventing structure may be a structure in which each of the outer peripheral surface of the retaining member and the inner peripheral surface of the disc spring is threaded and the retaining member and the disc spring are screwed together.

  According to the present invention, by providing a disc spring between the retaining member and the spring receiving member, the retaining member does not fall off from the end of the valve shaft within the range where the elastic force of the disc spring exerts an effect. A pressing force can be applied to the retaining member, and even if a surging phenomenon occurs where the valve spring cannot catch up with the valve operation, the valve and the retaining member are within the range where the elastic force of the disc spring is effective. Since it is configured to be movable within the range, it is possible to prevent the retaining member from being separated from the spring receiving member.

  In addition, even if the spring receiving member is displaced from the normal position or falls off, as long as the retaining member and the disc spring are fitted, the valve is within the range where the elastic force of the disc spring is effective. Since it is movable, the valve can be opened and closed accordingly.

It is sectional drawing which shows the valve operating mechanism of the internal combustion engine of 1st embodiment which concerns on this invention. It is sectional drawing which shows each component shown in FIG. 1, (a) shows a retaining member, (b) shows a disc spring, (c) shows a spring receiving member. It is sectional drawing which shows the restoring force of the disc spring shown in FIG. 1, (a) shows a mode that a disc spring deform | transforms flatly with the urging | biasing force of a valve spring, (b) is added to a cotter from the flat disc spring. Indicates pressing force. It is sectional drawing which shows operation | movement of the valve mechanism shown in FIG. 1, (a) shows a normal opening / closing movement, (b) shows the opening / closing movement when a surging phenomenon generate | occur | produces. It is sectional drawing which shows operation | movement in case the movement of the spring receiving member of the valve operating mechanism shown in FIG. It is sectional drawing which shows a part of valve operating mechanism of the internal combustion engine of 2nd embodiment which concerns on this invention, (a) shows when attaching a disc spring and a retaining member to a spring receiving member, (b) The case of normal opening and closing movement is shown. It is sectional drawing which shows the retaining member and disc spring of the valve mechanism of the internal combustion engine of 3rd embodiment which concern on this invention. It is sectional drawing which shows the valve mechanism of the internal combustion engine of a prior art, (a) shows the case where a surging phenomenon generate | occur | produces, (b) shows the case after a surging phenomenon generate | occur | produces.

  Hereinafter, a valve operating mechanism of an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings. In the embodiment, the valve mechanism is provided with a cam provided on a cam shaft driven by an engine (internal combustion engine) and a rocker arm that rotates by the action of the cam, and the rocker arm is one end of the valve. Although an example in which the opening / closing movement of the valve is performed by pushing will be described, the present invention is not limited to this.

  Further, the dimensions of the drawings are changed so that the configuration can be easily understood, and the ratios of the thicknesses, widths, lengths, and the like of the respective members and parts are not necessarily matched with those of the actually manufactured parts. In addition, the axial direction of the valve and the vertical direction in the figure is the x direction.

  First, a valve mechanism for an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the valve operating mechanism 1 includes a valve 2, a cotter (a retaining member) 3, a valve spring 4, and an upper spring seat (a spring receiving member; hereinafter referred to as a spring seat) 5. In addition to the configuration of a known valve operating mechanism, a disc spring 6 is provided which is fitted to the cotter 3 on the inner side and to the spring seat 5 on the outer side. The cotter 3 is moved inward by the elastic force of the disc spring 6. To maintain the engagement between the end of the shaft of the valve 2 and the cotter 3, and the warp of the disc spring 6 causes the valve 2 and the cotter 3 to be within a predetermined range with respect to the spring seat 5. It is configured to be movable.

  The valve 2 includes an intake valve that opens when air is supplied into the combustion chamber 7 of the cylinder, or an exhaust valve that opens when exhaust gas generated in the combustion chamber 7 is discharged from the combustion chamber 7. The valve 2 is formed in a cylindrical shape extending in the x direction, and a valve portion 2a that is in close contact with the valve seat 10 so as to close an opening of an intake or exhaust port 9 provided in the cylinder head 8. 8 includes a shaft portion 2 b inserted through the valve guide 11 fixed to 8, and an engagement portion 2 c provided at an end portion of the shaft portion 2 b and engaged with the cotter 3. An annular groove 2d having a substantially semicircular cross section is formed in the circumferential direction on the outer peripheral surface of the engaging portion 2c.

  The cotter 3 is composed of a pair of cotter division bodies 12 as shown in FIG. The cotter 3 includes a hollow cylinder having an inner peripheral surface 3a along the outer peripheral surface of the engaging portion 2c of the valve 2 and a tapered outer peripheral surface 3b that expands in the x direction when the cotter divided body 12 is combined. It is formed into a shape. The cotter 3 is formed with an annular protrusion 3c having a substantially semicircular cross section that engages with the annular groove 2d of the bulb 2 on the inner peripheral surface 3a.

  As shown in FIG. 1, the valve spring 4 is arranged to be biased between a spring seat 5 and a lower spring seat 13 fixed to the cylinder head 8.

  As shown in FIG. 2 (c), the spring seat 5 is provided with a fitting hole that expands in the x direction in the center and is provided with a tapered inner peripheral surface 5a.

  As shown in FIG. 2 (b), the disc spring 6 is formed by forming a circular plate having a conical shape having a fitting hole whose diameter is increased in the x direction at the center, and the cotter is formed by the fitting hole. 3 has a tapered inner peripheral surface 6a fitted to the tapered outer peripheral surface 3b, and is tapered so as to be fitted to the tapered inner peripheral surface 5a of the spring seat 5. The outer peripheral surface 6b is configured. In other words, it is different from a well-known technique of a disc spring in which a circular plate having a hole in the center is processed into a conical shape and has a disc shape with no bottom.

  A well-known disc spring has an inner diameter that expands when flattened. Therefore, when the disc spring is used as it is, the fitting with the cotter 3 is easily released. Therefore, the disc spring 6 of the present invention has a tapered inner peripheral surface 6 a that fits with the outer peripheral surface 3 b of the cotter 3, so that the fitting between the cotter 3 and the disc spring 6 does not come off. Has been devised.

  Further, the disc spring 6 is formed to warp in the x direction, and a restoring force (elastic force) is generated by the warping being deformed. And the cotter 3 is pressed inward by the restoring force, and the engagement between the valve 2 and the cotter 3 is maintained.

  Here, the restoring force will be described with reference to FIG. As shown in FIG. 3A, when the urging force F1 by the valve spring 4 is applied to the spring seat 5, the tapered inner peripheral surface 5a of the spring seat 5 and the tapered outer peripheral surface 6b of the disc spring 6 are fitted. In combination, an upward force F <b> 2 is applied from the spring seat 5 to the disc spring 6. Then, as shown in FIG. 3B, the disc spring 6 is deformed so as to be flat.

  A restoring force (elastic force) F3 is generated in the flat disc spring 6, and the tapered inner peripheral surface 6a of the disc spring 6 and the tapered outer peripheral surface 3b of the cotter 3 are fitted by the restoring force F3. Thus, a pressing force F4 is applied to the cotter 3. Thus, the valve 2, the cotter 3, the disc spring 6, and the spring seat 5 move together, and the pressing force F 4 by the restoring force F 3 of the disc spring 6 can be applied to the cotter 3. It is possible to prevent the engagement portion 2c from being disengaged.

  As described above, the pressing force F4 is applied from the disc spring 6 to the cotter 3 as long as the restoring force F3 of the disc spring 6 is within the effective range. This range refers to the deflection of the disc spring 6, that is, the deformation of the warpage of the disc spring 6. Hereinafter, the range in which the restoring force F 3 exerts an effect is referred to as a deflection Δd.

  That is, since the pressing force F4 is applied to the cotter 3 within the range of the deflection Δd, even when the cotter 3 moves relative to the spring seat 5 by the deflection Δd, the engagement between the valve 2 and the cotter 3 can be released. Absent. Therefore, even if the surging phenomenon occurs and the spring seat 5 is positioned below the cotter 3, if the position is within the deflection Δd, the pressing force F 4 due to the restoring force F 3 of the disc spring 6 is applied to the cotter 3. As a result, the engagement between the valve 2 and the cotter 3 can be prevented from being disengaged.

  This deflection Δd can be set in a predetermined range from the material and shape of the disc spring 6. If this deflection Δd is large, even if the cotter 3 and the spring seat 5 are largely separated when a surging phenomenon occurs, it is possible to apply a pressing force F4 due to the restoring force F3 of the disc spring 6 to the cotter 3.

  In addition, the disc spring 6 can be assembled with a tool similar to a current valve assembly tool without requiring special parts such as a shape memory alloy. Furthermore, the number of fixtures in the peripheral part of the cotter 3 is the minimum configuration in which the disc spring 6 is only added. Therefore, it can be easily assembled with a simple structure, and the manufacturing cost can be reduced.

  Next, the operation of the valve mechanism 1 of the internal combustion engine will be described with reference to FIGS. FIG. 4A shows a normal opening / closing movement, and FIG. 4B shows an opening / closing movement when a surging phenomenon occurs. FIG. 5 shows an opening / closing motion after the surging phenomenon occurs and the fitting between the spring seat 5 and the disc spring 6 is released.

As described above, the valve 2, the cotter 3, the disc spring 6, and the spring seat 5 are integrated by the urging force F <b> 1 from the valve spring 4. When pushed, as shown in FIG. 4A, an opening / closing movement is performed.

  On the other hand, as shown in FIG. 4B, a surging phenomenon occurs in which the operation of the valve spring 4 cannot catch up with the opening and closing movement of the valve 2 due to the high speed rotation of the engine, and the spring seat 5 is located below the cotter 3. If the position is within the range of the deflection Δd of the disc spring 6, the valve 2, the cotter 3, the disc spring 6, and the spring seat 5 can be opened and closed without being released. Can do.

  Further, as shown in FIG. 5, after the surging phenomenon occurs, the spring seat 5 is located far below the cotter 3 and the spring seat 5 and the disc spring 6 are disengaged, then the spring seat 5 and the disc When the spring 6 comes into contact again, when the tapered inner peripheral surface 5a of the spring seat 5 and the tapered outer peripheral surface 6b of the disc spring 6 do not match, the valve 2 is subjected to the deflection Δd of the disc spring 6. Can be used to open and close. That is, the valve mechanism 1 is a mechanism in which a fail safe for the deflection Δd works against an unexpected situation as shown in FIG.

  Next, a valve mechanism for an internal combustion engine according to a second embodiment of the present invention will be described with reference to FIG. In addition to the configuration of the first embodiment, the valve mechanism 20 includes a disc spring 6 so that the spring seat 5 and the disc spring 6 are not separated as shown in FIGS. 6 (a) and 6 (b). The tongue portion (separation preventing member) 21 is provided.

  The tongue portion 21 is provided at the bottom of the disc spring 6 and prevents the disc spring 6 from separating from the spring seat 5 when the disc spring 6 is warped. Is also configured to protrude outward. In addition, the tongue portion 21 is formed in a circular shape having a hole in the central portion so as to be disposed over the entire circumference of the disc spring 6.

  In addition, this tongue part 21 is not limited to said structure, For example, it forms in plate shape so that it may be partially arrange | positioned on the outer periphery of the disc spring 6, and is arrange | positioned radially from the center of the disc spring 6. FIG. It may be a thing.

  The disc spring 6 to which the tongue portion 21 is attached can be assembled to the spring seat 5 by contracting the disc spring 6 as shown in FIG.

  According to this configuration, during the normal opening and closing movement, as shown in FIG. 6B, when the disc spring 6 becomes flat, the tongue 21 comes into contact with the bottom of the spring seat 5, It is possible to prevent the disc spring 6 from moving away from the spring seat 5 in the x direction. In addition, since the taper-shaped inner peripheral surface 5a of the spring seat 5 and the taper-shaped outer peripheral surface 6b of the disc spring 6 are fitted, they do not leave in the reverse direction of the x direction.

  Further, when the surging phenomenon occurs, even if the disc spring 6 tries to move away from the spring seat 5 in the x direction, the tongue portion 21 is caught on the bottom of the spring seat 5, so that the disc spring 6 moves from the spring seat 5 in the x direction. It is possible to prevent separation.

  Next, a valve mechanism for an internal combustion engine according to a third embodiment of the present invention will be described with reference to FIG. In addition to the configuration of the first embodiment, the valve mechanism 30 is configured to fix the outer peripheral surface 3b of the cotter 3 and the inner peripheral surface 6a of the disc spring 6 so that the cotter 3 and the disc spring 6 are not separated from each other. The prevention structure 31 is configured.

The configuration for fixing the outer peripheral surface 3b of the cotter 3 and the inner peripheral surface 6a of the disc spring 6 is not particularly limited, but in this embodiment, the male screw portion 32 is provided on the outer peripheral surface 3b of the cotter 3 and the inner periphery of the disc spring 6 is provided. Each surface 6a is provided with a female thread portion 33, and the disc spring 6 is rotated during assembly so that the male screw portion 32 and the female screw portion 33 are screwed together, whereby the outer peripheral surface 3b of the cotter 3 and the inner peripheral surface 6a of the disc spring 6 are provided. Fixed.

  Note that a female screw portion may be provided on the outer peripheral surface 3 b of the cotter 3, and a male screw portion may be provided on the inner peripheral surface 6 a of the disc spring 6.

  According to this configuration, since the outer peripheral surface 3 b of the cotter 3 and the inner peripheral surface 6 a of the disc spring 6 are fixed, the cotter 3 is not separated from the disc spring 6. Thereby, since the engagement between the valve 2 and the cotter 3 is not released, it is possible to prevent the valve 2 from being dropped due to the cotter 3 being dropped.

  In addition, the configuration of the third embodiment is added to the configuration of the valve mechanism 20 of the second embodiment, and the engagement of the cotter 3 and the disc spring 6 and the fitting of the disc spring 6 and the spring seat 5 are performed. You may comprise so that each may be maintained.

  Moreover, it is good also as a structure which attaches to the cotter 3 the cyclic | annular or C-shaped ring which is a well-known technique, for example by Unexamined-Japanese-Patent No. 2012-31743. In addition, the present invention can be applied to a valve operating mechanism including a plurality of valve springs 4.

  In the valve mechanism of the internal combustion engine of the present invention, by providing a disc spring between the retaining member and the spring receiving member, the retaining member can be moved from the end of the valve shaft within the range in which the elastic force of the disc spring is effective. In order not to fall off, it is possible to apply a pressing force to the retaining member, and even if a surging phenomenon occurs where the valve spring does not catch up with the operation of the valve, within the range where the elastic force of the disc spring has an effect, Since the retaining member is configured to be movable within the range, it can be prevented that the retaining member is separated from the spring receiving member. Therefore, the retaining member is used particularly for a valve operating mechanism of an engine of a large vehicle such as a truck. be able to.

1, 20, 30, 1X Valve mechanism 2 of internal combustion engine Valve 3 Cotter (prevention member)
4 Valve spring 5 Spring seat (spring receiving member)
6 Disc spring 21 tongue (separation prevention member)
31 Separation prevention structure

Claims (3)

An internal combustion engine comprising a retaining member that engages with an end portion of a valve shaft, and a spring receiving member that is biased by a valve spring, the spring receiving member and the valve being configured to move together via the retaining member. In the valve mechanism of the engine,
It has a disc spring that has a fitting hole in the central part, and the central part warps upwards in the upward direction,
The disc spring, the inner circumferential surface fitted to the outer peripheral surface of the stop member of the fitting hole, the outer peripheral surface of the disc spring is fitted with the inner peripheral surface of the spring receiving member, warping of the disc spring the deformation, the outer peripheral surface of the inner peripheral surface the retaining pressing to Rutotomoni the disc springs inwardly the outer peripheral surface of the member of the fitting hole presses the inner peripheral surface of the spring receiving member outwardly, further , valve train for an internal combustion engine, characterized in that the said stop member and the valve to the extent that warping of the disc spring is deformed and movable in the vertical direction with respect to the spring receiving member.   The valve operating mechanism for an internal combustion engine according to claim 1, wherein the disc spring is provided with a separation preventing member so that the spring receiving member and the disc spring are not separated.   3. The internal combustion engine according to claim 1, wherein an outer peripheral surface of the retaining member and an inner peripheral surface of the disc spring are configured to prevent separation so that the retaining member and the disc spring are not separated from each other. Valve mechanism.

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