JP2007297999A - Vortex flow generating device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vortex flow generating device for an internal combustion engine capable of preventing damage even when abnormal pressure is applied from the internal combustion engine side, suppressing inclination of a gear and preventing abnormal wear of the gear. <P>SOLUTION: This vortex flow generating device for the internal combustion engine is provided with a coil spring 36 provided between a drive shaft 42 to which a variable intake throttle valve 4a is fixed and a drive device 2 for driving the drive shaft 42, energizing the variable intake throttle valve 4a to the closing direction and driving the variable intake throttle valve 4a to the full opening direction when abnormal pressure is generated. Since the shapes of winding start and winding end of the coil spring 36 are narrowed down in the inner diameter side, inclination of an input spur gear 34c (integrally molded member 34) engaged with the drive shaft 42 is suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vortex generator for an internal combustion engine that generates a vortex in intake air in the internal combustion engine.

  In order to improve the combustion efficiency by generating a swirl flow such as a swirl flow or a tumble flow of an air-fuel mixture in the combustion chamber, a vortex flow generator is disposed downstream of the throttle valve of the intake pipe. In such a vortex generator, a part of the intake passage is closed by a variable intake throttle valve to generate a vortex flow by forming a one-sided ventilation state, and the variable intake throttle valve that forms the one-sided ventilation state is controlled. The shaft and the valve body have a structure in which a rotational moment is easily generated around the control shaft.

On the other hand, in an internal combustion engine for automobiles, the adoption of lean burn combustion and EGR control is progressing for improving fuel efficiency, and combustion adaptation by proper use according to operating conditions is achieved. For this reason, for example, deterioration of combustion due to the operation timing of the variable intake throttle valve and EGR may occur, or abnormal combustion such as backfire may occur depending on operating conditions. For this reason, in a vortex generator having a variable intake throttle valve that is susceptible to rotational moment, a structure that is not damaged by abnormal pressure from the internal combustion engine side is desired.
In addition, when an impact load due to the abnormal pressure or a driving torque applied to open and close the variable intake throttle valve is applied, an eddy current generator that can generate eddy currents is desired.

  For this reason, in the vortex generator for an internal combustion engine of the prior art disclosed in Patent Document 1, a drive shaft of a variable intake throttle valve that can open and close a part of an intake air passage to the internal combustion engine, and this drive shaft By providing pressure relief means between the driving device and the driving device, even if an impact load is applied to the variable intake throttle valve from the internal combustion engine side, damage to the vortex generator can be prevented.

JP 2001-248449 A

  That is, in Patent Document 1, for the purpose of preventing device damage when backfire occurs, the input spur gear portion (drive device for driving the drive shaft) 31 and the drive shaft (drive shaft of the variable intake throttle valve) 42 in FIG. Is not fixed, and is structured to move integrally by a spring (pressure absorbing means) 36. As a result, depending on the positions of the engaging portions 32b and 33b to which the first plate 32, the second plate 33 and the spring 36 are attached, the clearance between the hole 34b of the integrally molded member 34 and the drive shaft 42, an arc-shaped input A phenomenon occurs in which the spur gear 34c is inclined with respect to the drive shaft 42. When the input spur gear 34c is tilted, there is a problem that the engagement ratio between the output spur gear 27 and the input spur gear 34c of the actuator is reduced, and abnormal gear wear occurs.

  The present invention has been made in view of the above problems, and its purpose is to prevent damage even when abnormal pressure such as backfire is applied from the internal combustion engine side, and to prevent abnormal wear of the gear, And it is providing the eddy current generator for internal combustion engines which can suppress a deformation | transformation of a gear and abrasion of a spring.

The present invention provides a vortex generator for an internal combustion engine as set forth in each of the claims as means for solving the problems.
The vortex generator for an internal combustion engine according to claim 1 is provided between the drive shaft 42 to which the variable intake throttle valve 4a is fixed and the drive device 2 that drives the drive shaft 42, and the variable intake throttle valve 4a. Is driven to close the inner diameter side of the coil spring 36, which is a biasing means for operating the variable intake throttle valve 4a in the fully open direction when abnormal pressure occurs. This suppresses the inclination of the input spur gear 34c engaged with the shaft 42, thereby preventing abnormal gear wear caused by the inclination of the input spur gear 34c. Further, even if abnormal pressure from the internal combustion engine is applied to the variable intake throttle valve 4a, damage to the vortex generator can be prevented.

The eddy current generating device according to claim 2 is configured to gradually narrow down the narrowed shape of the coil spring 36, whereby the input spur gear 34c can be urged in the radial direction over a relatively wide range. The inclination of the spur gear 34c can be suppressed, and the contact pressure between the coil spring 36 and the input spur gear 34c can be lowered, and the deformation of the gear and the wear on the coil spring can be suppressed.
In the eddy current generator according to claim 3, the winding start end 36a and the winding end end 36b of the coil spring 36 are located at the counter electrode across the central axis L of the coil spring 36. The force that suppresses the inclination of the spar gear 34c works most effectively.

  Hereinafter, an eddy current generator for an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating the concept of a vortex generator 1 according to the present invention as a part of an intake device for an internal combustion engine. The vortex generator 1 includes a drive device 2 having a speed reduction structure, a pressure absorbing means 3 that absorbs an impact load from the internal combustion engine side, and an intake pipe (hereinafter referred to as a variable intake throttle valve 4a that forms a one-sided ventilation state). (Referred to as a variable intake throttle valve portion) 4 and the like.

  The variable intake throttle valve section 4 includes a housing 41 that forms an intake air passage and introduces intake air to the internal combustion engine, and a rotatable variable intake throttle valve 4a that adjusts the opening area. The housing 41 is provided with an air passage 41a for introducing intake air and a partition wall 41d for dividing the intake air introduced halfway into air passages 41b and 41c. The opening area of the air passage 41b is adjusted by the variable intake throttle valve 4a.

  The variable intake throttle valve 4a includes a drive shaft 42 that is rotatably supported in the housing 41, and a valve body 43 that rotates together with the drive shaft 42 and regulates intake air flowing through the air passage 41b. ing. The drive shaft 42 is rotated by the drive device 2 having a speed reduction structure via the pressure absorbing means 3. FIG. 1 shows a state where the variable intake throttle valve 4a is fully opened. The shape of the valve body 43 is, for example, an elliptical shape with one side 43a being semicircular and the other side 43b having the drive shaft 42 as a long axis across the drive shaft 42. The valve body 43 has a structure that easily receives a rotational moment around the drive shaft 42.

  In the state where the vortex generator 1 is mounted on a vehicle, the upstream side of the intake air is airtightly coupled to the throttle valve 200, and the downstream side of the intake air is an internal combustion engine (engine) 300 having a combustion chamber (not shown). Airtight communication. The flow of the intake air is indicated by an arrow A and flows separately as indicated by arrows B and C. Further, the driving device 2 rotates the driving shaft 42 that rotates together with the valve body 43 by a driving current controlled by the computer 60 based on signals from the accelerator sensor 61, the rotation speed sensor 62, and the like. Thereby, the valve body 43 is rotated to the position indicated by the two-dot chain line in FIG. 1 to fully close the air passage 41b, thereby forming a biased air flow only by the arrow B, and suction in the one-sided ventilation state By sending air into the combustion chamber, a swirl flow or tumble flow of the air-fuel mixture is generated in the combustion chamber.

  FIG. 2 is a configuration diagram showing the driving device 2 in the vortex generator 1. The drive device 2 includes a drive motor M, a speed reduction mechanism unit 20, and a casing 21. The drive motor M is a motor capable of forward / reverse drive such as a DC motor. The casing 21 holds the drive motor M and the speed reduction mechanism 20 and is fixed to the variable intake throttle valve 4 by a fastening member.

The speed reduction mechanism unit 20 includes a speed reduction mechanism 20a that reduces the power from the drive motor M and an impact absorbing member 22 that is disposed between a plurality of gears that constitute the speed reduction mechanism 20a.
The reduction mechanism 20 a includes a worm gear 25 fixed to the output shaft of the drive motor M, a helical gear 26 that meshes with the worm gear 25, and an output spur gear 27 that is arranged coaxially with the helical gear 26. Between the helical gear 26 and the output spur gear 27, an impact absorbing member 22 that is rotatable together with the gears 26 and 27 is disposed. The helical gear 26 and the output spur gear 27 are rotatably supported by a shaft 28 disposed perpendicular to the worm gear 25 axis. One end of the shaft 28 is fixed to a housing 21 that forms a cylindrical inner peripheral wall that accommodates the speed reduction mechanism 20 a, and the other end 28 b is fixed to a sealing member 21 b that forms a part of the housing 21. The housing 21 and the sealing member 21b are formed of a resin material, and are integrally formed by, for example, ultrasonic welding.

The shock absorbing member 22 has a substantially cylindrical shape and is disposed at an end portion in contact with both the gears 26 and 27. The shock absorbing member 22 is integrally formed by sandwiching an elastic member made of a rubber material between two plates formed of, for example, a rolled steel plate.
The shock absorbing member 22 is disposed integrally with a helical gear 26 that meshes with a worm gear 25 fixed to the output shaft of the drive motor M. In the case where the torque transmission is impacted, for example, at the moment when the valve body 43 is fixed in the fully closed position, the impact load transmitted to the worm gear is caused by the torsional action of the elastic member of the shock absorbing member 22 being deformed. It is mitigated to prevent the worm gear from being tightened.

  Further, during the operation of the driving device 2, since the rotational torque of the motor M is deflecting the shock absorbing member 22 by the twisting action, the backlash of the gear can be reduced by the reaction force. For this reason, the self-locking effect of the worm gear 25 that functions when the driving device 2 is stopped and the fluttering of the valve body 43 of the variable intake throttle valve 4a can be prevented regardless of the operation or non-operation of the driving device 2.

  FIG. 3 is an exploded view of the pressure absorbing means 3. For example, when abnormal combustion such as backfire occurs, the variable intake throttle valve 4a from the engine side has an abnormality greater than the intake air pressure (for example, the maximum supercharging pressure in a supercharged engine) generated under normal engine operating conditions. Pressure may be applied as an impact load. In the shape of the valve body 43 of the variable intake throttle valve 4a of the present invention that is susceptible to a rotational moment, a part of the vortex generator 1 is damaged particularly when an abnormal pressure or the like is applied to the valve body 43. There is no need to generate eddy currents. The pressure absorbing means 3 of the present invention relieves an impact load applied to each member of the vortex generator 1 by an abnormal pressure generated by abnormal combustion or the like. As shown in FIG. 3, the pressure absorbing means 3 is a first input spur gear portion 31 provided on the drive shaft 42 of the variable intake throttle valve 4 a and a first shaft fixed to the drive shaft 42 and rotatable together with the drive shaft 42. By connecting the plate 32 with a coil spring 36 that is an urging means, when an abnormal pressure is generated, the coil spring 36 is bent against an impact load due to the abnormal pressure applied to the valve body 43, thereby allowing for input. The spur gear part 31 and the drive device 2 fitted can be separated. Thereby, the valve body 43 integral with the drive shaft 42 can be rotated from the fully closed state to the fully open side in accordance with the abnormal load received in the fully closed state, that is, the impact load of the abnormal pressure. For this reason, the abnormal load received in the fully closed state is mitigated by absorbing the abnormal pressure.

  The configuration of the pressure absorbing means 3 will be described in more detail. The first plate 32 comes into contact with a fitting hole for fixing to the drive shaft 42, a recess 32 b for engaging one end 36 a of the coil spring 36, and a cushion 35 accommodated in the input spur gear portion 31. And a protrusion 32c. The input spur gear portion 31 includes a second plate 33 that engages with one end 36b of the coil spring 36, a cushion 35 that is sandwiched between the second plate 33 and the protrusion 32c of the first plate 32 in the circumferential direction, And an integrally molded portion 34 having an input spur gear 34c sandwiched between both plates 32 and 33. The second plate 33 includes a hole 33 a that can slide and rotate with the drive shaft 42, a recess 33 b for engaging one end 36 b of the coil spring 36, and a protrusion 33 c that contacts the cushion 35. Yes. The cushion 35 is formed of, for example, a rubber material, has a substantially arc shape, and has a protrusion in the radial direction so as to engage with the guide portion 34d. The integrally formed member 34 can be engaged with the protrusion 33 c of the second plate 33, and can slide on the drive shaft 42 and a circumferential groove 34 a that can rotate the second plate 33 around the drive shaft 42 in the fully open direction. And the guide hole 34d for restricting the movement of the cushion 35 in the circumferential direction and the arc-shaped input spur gear 34c set in a range where the output spur gear 27 can be engaged with the hole 34b. ing. It should be noted that the shaft end 42 a of the drive shaft 42 is provided on the shaft end 42 a so that the first plate 32, the input spur gear portion 31, and the coil spring 36 can maintain an arrangement in which the first plate 32 can rotate with each other according to the deflection of the coil spring 36. An axial locking portion is provided through the washer 37 by, for example, caulking.

  Therefore, the coil spring 36 is bent against the abnormal pressure, and the drive device 2 fitted to the input spur gear portion 31 can be disconnected, and the valve body 43 is subjected to an abnormal pressure impact load from the engine side. It can be rotated from the fully closed state to the fully open side. In addition, even when the variable intake throttle valve 4a is fully open and fully closed and the drive device 2 and the drive shaft 42 can rotate together, the valve body 43 is subjected to engine vibration or intake air flow. The cushion 35 is provided so as not to damage the speed reduction mechanism 20 of the drive device 2. Furthermore, when abnormal pressure occurs, for example, when the fully closed state changes to the pressure absorbing state and the abnormal pressure is absorbed and then returns to the fully closed state again, even if an impact load is generated by the biasing force of the coil spring 36, Since the protrusion 32c of the first plate 32 fixed to the drive shaft 42 presses the protrusion 33c of the second plate 33 via the cushion 35, the cushion 35 can absorb the impact load due to the urging force.

  Next, the shape of the coil spring 36, which is a feature of the present embodiment, will be described. As shown in FIG. 5A, the coil spring 36 winds the outer periphery of a cylindrical integrally formed portion 34 formed integrally with the input spur gear 34c in a coil shape with a constant curvature from the start of winding to the end of winding. Thus, a predetermined gap g is formed between the inside of the coil spring 36 and the outer peripheral surface of the integral molding portion 34. Therefore, even if the phenomenon in which the input spur gear 34c (integral molding portion 34) is inclined with respect to the drive shaft 42 as described in the prior art occurs, the coil spring 36 has the coil spring 36 as shown in FIG. The force which suppresses the inclination of the integrally molded member 34 does not work. For this reason, conventionally, due to the inclination of the input spar gear 34c, the meshing rate of the output spar gear 27 and the input spar gear 34c decreases, and abnormal gear wear occurs.

  Therefore, in this embodiment, as shown in FIGS. 4A and 4B, the integrally formed member 34 (input spur gear 34c) is formed by narrowing the winding start and end of the coil spring 36 toward the inner diameter side. By biasing in the radial direction, the inclination of the integrally molded member 34 is suppressed. In this case, the coil spring 36 may be suddenly narrowed to the inner diameter side from the vicinity of the start of winding and the vicinity of the end of winding, or, as shown in FIG. The start and end of winding may be gradually narrowed to the inner diameter side so as to come into contact with the outer peripheral surface within a range of approximately 200 degrees. When it is gradually narrowed down, the gear (integral molded member) can be urged in the radial direction over a wide range (approximately 200 degrees), and the inclination of the gear can be suppressed more stably. Further, the contact pressure between the coil spring 36 and the integrally formed member 34 can be lowered, and the deformation of the gear and the wear of the coil spring can be suppressed. Further, if the winding start end 36a and the winding end end 36b of the coil spring 36 are positioned at the counter electrode across the central axis L of the coil spring 36, the urging force in the radial direction can be effectively applied.

The operation of the vortex generator 1 of the present invention having the above configuration will be described.
(1) A state in which no vortex is generated When the current is not supplied to the driving device 2, the valve element 43 in the fully opened state is held inclined with respect to the axial direction of the intake air passage 41a. Since the force of the intake air flow acts on the valve body 43, the valve body 43 can be prevented from fluttering due to engine vibration or intake air pulsation. For this reason, under operating conditions where it is not necessary to generate a vortex in the combustion chamber, the intake air can be supplied to the combustion chamber without disturbing the flow of the intake air flowing through the vortex generator 1. In addition, you may supply an electric current to the drive device 2, and may hold | maintain the valve body 43 in a full open state.

(2) State in which vortex flow is generated The air passage 41b is fully closed, and only one air passage 41c forms a one-sided ventilation state to generate vortex flow. The valve element 43 is rotated in the fully closed direction by the torque of the motor M. When the fully closed side is reached, the torque of the motor M presses the valve body 43 so as to contact the circumferential protrusion 41 s provided in the peripheral wall of the housing 41. At the moment of contact, an impact load is applied to the valve body 43 by the torque of the motor M. At this time, the shock absorbing member 22 incorporated in the speed reduction mechanism unit 20 absorbs and relaxes the shock load by the torsional action caused by the bending of the elastic member against the torque of the motor M. For this reason, since the transmission of shocking torque can be eased, it is possible to prevent the screw tightening state of the worm gear 25 built in the speed reduction mechanism unit 20 from occurring. Therefore, the eddy current generating device 1 can be operated without being damaged while the driving device 2 is screwed while the current is being supplied to the driving device 2.

  During the operation of the driving device 2, the torque of the motor M causes the shock absorbing member 22 to bend due to the twisting action, so that the backlash of the gear can be closed by the reaction force. For this reason, the self-locking effect of the worm gear 25 that functions when the driving device 2 is stopped and the fluttering of the valve body 43 of the variable intake throttle valve 4a can be prevented regardless of the operation or non-operation of the driving device 2.

(3) When abnormal pressure is generated When abnormal pressure is generated in the eddy current generator 1 due to abnormal combustion of the engine or the like, the pressure absorbing means 3 is activated, and the impact load due to the abnormal pressure received by the valve body 43 and the coil spring 36 The valve element 43 is rotated to the fully open side at a position in balance with the urging force. This prevents the variable intake throttle valve 4a from being damaged and prevents the screw mechanism of the speed reduction mechanism 20 from being tightened. Therefore, even after the occurrence of abnormal pressure, the operating characteristics before the occurrence do not change, and the original design aims. Can maintain eddy current generation.
In addition, the pressure absorption means 3 will push back the valve body 43 to the position before generation | occurrence | production by the coil spring 36, if the generation | occurrence | production state of abnormal pressure is eliminated. For this reason, the pressure absorbing means 3 is preferably provided with a cushion 35 in order to absorb the impact load generated by the urging force.

It is a figure explaining the concept of the eddy current generator of this invention. It is a block diagram which shows the drive device in the eddy current generator of embodiment of this invention. It is an exploded view of the pressure absorption means in the eddy current generator of embodiment of this invention. It is (a) top view and (b) side view which show the shape of the coil spring in the eddy current generator of embodiment of this invention. It is (a) top view and (b) side view which show the shape of the coil spring in the conventional eddy current generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eddy current generator 2 Drive apparatus 3 Pressure absorption means 4 Variable intake throttle valve part (intake pipe provided with variable intake throttle valve)
4a Variable intake throttle valve 20 Deceleration mechanism portion 22 Shock absorbing member 25 Worm gear 26 Helical gear 27 Output spur gear 31 Input spur gear portion 32 First plate 33 Second plate 34 Integrated molding member (integrated molding portion equipped with input spur gear)
34c Input spur gear 35 Cushion 36 Coil spring (biasing means)
36a Winding end (one end)
36b End of winding (one end)
41 Housing 41a Intake air introduction passage 42 Drive shaft 43 Valve element

Claims (3)

A housing (41) forming an intake air passage to the internal combustion engine;
A drive shaft (42) rotatably disposed in the housing (41);
A variable intake throttle valve (4a) fixed to the drive shaft (42) and capable of opening and closing a part (41b) of the intake air passage;
A drive device (2) having a speed reduction mechanism (20a) and driving the drive shaft (42) via the speed reduction mechanism;
Provided between the drive shaft (42) and the drive device (2) to urge the variable intake throttle valve (4a) in a closing direction. When an abnormal pressure occurs, the variable intake throttle valve is fully opened. Biasing means (36) for actuating
In an internal combustion engine eddy current generator comprising:
The biasing means is a coil spring (36), and the input spur gear engaged with the drive shaft (42) is formed by narrowing the winding start and end of the coil spring (36) toward the inner diameter side. An eddy current generator for an internal combustion engine, characterized by suppressing the inclination of (34c).   2. The vortex generator for an internal combustion engine according to claim 1, wherein the narrowed shape of the coil spring (36) is gradually narrowed.   A winding start end (36a) and a winding end end (36b) of the coil spring (36) are located at the counter electrode across the central axis (L) of the coil spring (36). Item 3. An eddy current generator for an internal combustion engine according to Item 1 or 2.

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