JP4204055B2 - Throttle valve device - Google Patents

Description

  The present invention relates to a throttle valve device, and in particular, a torsion spring provided to urge the valve in a throttle closing direction also acts to press the throttle valve main body against the throttle body along the extension direction of the shaft portion thereof. The present invention relates to a throttle valve device set as described above.

  In order to adjust the output of the internal combustion engine by adjusting the amount of the air-fuel mixture sucked into the combustion chamber of the internal combustion engine, a throttle valve device is incorporated in the carburetor and the electronic fuel injection device. 2. Description of the Related Art A throttle valve device is known that includes not only a throttle valve body but also an electrical operation element such as a throttle sensor and an idle control valve (IACV). In Japanese Patent Laid-Open No. 9-303164, a housing for accommodating a throttle sensor, a pressure sensor and the like is formed separately from the throttle body and attached to the outer wall of the throttle body, and a case for accommodating another electrical operation element is provided in the throttle body. And a throttle valve device that is integrally molded.

Japanese Patent Application Laid-Open No. 4-66738 describes a system in which a printed wiring board constituting an ECU is arranged in a throttle body.
JP-A-9-303164 JP-A-4-66738

  The conventional throttle valve device has a torsion spring provided to twist the shaft portion of the throttle valve body in the throttle closing direction. The torsion spring acts to twist the throttle valve body and simultaneously urge the shaft portion in the extension direction in the throttle body. However, the torsion spring disposed concentrically around the shaft portion of the throttle valve body extends and is fixed to a position where its end portion is offset from the shaft portion. For this reason, the force of the torsion spring that urges the shaft portion in the extending direction also acts in the direction in which the shaft portion is inclined. As a result, air leakage may occur in a gap formed between the throttle valve body and the throttle body.

  An object of the present invention is to provide a throttle valve device having a structure capable of preventing the torsion spring from acting to incline the throttle valve body.

  In order to achieve the above object, the present invention is enlarged at one end of the shaft portion to transmit a butterfly valve portion, a shaft portion projecting from the butterfly valve portion on both sides, and an operating force for throttle adjustment from the outside. A throttle valve body for an internal combustion engine having a throttle valve body comprising a drum portion and a throttle body for housing the throttle valve body in a state where the shaft portion is rotatably supported. A cover that covers the drum portion from the side of the drum portion, and a compression coil type torsion spring that is interposed between the drum portion and the cover and biases the drum portion in the closing direction. The coil portion of the torsion spring is disposed concentrically with the throttle valve body, and the coil of the torsion spring There is a first feature in the cover and the drum portion at both ends bent in Le radially inward direction to a point which is respectively engaged with Mawari stop.

  In addition, the present invention has a second feature in that a slit is formed in the cover and the drum portion along the diameter of the drum portion in order to fit both end portions of the torsion spring.

  Further, the present invention comprises a butterfly valve portion, a shaft portion protruding from the butterfly valve portion on both sides, and a drum portion formed on one end of the shaft portion so as to transmit an operating force for throttle adjustment from the outside. In a throttle valve device for an internal combustion engine having a throttle valve main body and a throttle body that accommodates the throttle valve main body in a state in which the shaft portion is rotatably supported, the throttle valve device is formed concentrically with the shaft portion and is formed from the drum portion. An annular groove having a depth reaching the shaft portion adjacent to the drum portion; a slit formed along a diameter of the drum portion and the shaft portion at an inner portion of the annular groove; Spring holding portion having a groove which is disposed around the throttle and has a throttle closing direction opened and a throttle opening direction closed. A compression coil comprising: a coil portion; one end portion bent inward of the coil diameter of the coil portion; and the other end portion bent from the coil portion so as to protrude in a plurality of protruding directions outward from the coil diameter. A torsion spring of the type, one end of the torsion spring being inserted into the slit, the coil part being inserted into the annular groove, and the overhanging part of the other end being a throttle closing direction of the throttle valve body There is a third feature in that it is inserted into the groove of the spring holding portion in a state where a twist is applied.

  According to the present invention having the first characteristic, the torsion spring is supported by the cover and the drum portion at both ends bent to the inside of the coil diameter. Therefore, the force acting when the torsion spring is extended acts within the coil diameter of the torsion spring, and this force acts on the center of rotation of the throttle valve body to push the throttle valve body in the longitudinal direction. That is, the force that presses the throttle valve body against the throttle body does not deviate from the core, which eliminates the problem that the throttle valve body tilts and creates a gap with the throttle body.

  According to the second feature, the torsion spring bent inwardly of the coil diameter is fitted into the slit formed in the diameter direction of the drum portion, and the force of the torsion spring correctly acts on the rotation center of the throttle valve body. .

  According to the third feature, the torsion spring is supported by the drum portion at one end bent to the inside of the coil diameter, and is provided around the drum portion at the other end of the plurality of portions protruding from the coil. Supported by In any end, the repulsive force of the spring can be applied in the direction of the rotation center axis of the throttle valve body so as not to deviate from the rotation center of the throttle valve body.

  Furthermore, in the third feature, the spring holding portion is opened in the throttle closing direction, and the torsion spring is supported by the groove closed in the throttle opening direction. Therefore, the torsion spring is twisted in advance in the twisting direction. In the state where the repulsive force is stored, both ends of the protruding portion of the torsion spring are fitted into the groove from the open side and supported.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a sectional view of an essential part of an internal combustion engine including a throttle valve device according to an embodiment of the present invention. In the figure, an intake valve 3 is disposed in an intake port 2 formed in a cylinder head 1 of an internal combustion engine. An intake pipe 4 that introduces an air-fuel mixture into the intake port 2 includes a base 5 coupled to the cylinder head 1, a heat insulator 6 formed of a heat insulating material, an air cleaner case 7, and a throttle body 8. In a portion of the intake pipe 4 formed at the lower part of the air cleaner case 7, a fuel injection valve 9 is disposed with its injection hole directed into the intake pipe 4. The heat insulator 6 prevents the heat from the engine from being directly conducted to the air cleaner case 7 and the throttle body 8, and can form the air cleaner case 7 and the throttle body 8 from a resin material having relatively low heat resistance. To.

  The throttle body 8 is incorporated in the air cleaner case 7, and the intake port 81 projects into the air cleaner case 7. Air that has been purified by an air cleaner body (air filter) (not shown) is introduced into the intake pipe 4 from the expanded intake port 81 at the top of the throttle body 8 during the intake stroke of the internal combustion engine. A throttle valve body 10 is pivotally supported on the throttle body 8 so as to be swingable. The throttle valve body 10 includes a butterfly valve portion (hereinafter simply referred to as “valve portion”) 11 and a shaft portion 12 that supports the valve portion 11 on the throttle body 8.

  FIG. 1 is a sectional view of a throttle valve device, and FIG. 3 is a front view thereof. 1 and 3, the throttle valve body 10 assembled to the throttle body 8 includes a valve portion 11, a shaft portion 12, and a drum portion 13. The shaft portion 12 supports the valve portion 11 on the throttle body 8 at both ends. A throttle cable (not shown) for rotating the valve 8 to adjust the throttle opening is connected to the drum portion 13 from the outside. The valve part 11, the shaft part 12, and the drum part 13 are integrally molded with resin.

  The cross-sectional shape of the intake pipe 4 at the position where the valve portion 11 and at least the valve portion 11 are disposed is substantially square (see FIG. 3), and the valve portion 11 is formed in the throttle body 8 in the closed state of the throttle valve. It touches the surface of the step. This step is formed by shifting the axis of the intake pipe 4 between the upstream side and the downstream side of the valve portion 11 (see the cross-sectional shape of the throttle body 8 in FIG. 2).

  The throttle body 8 has a wall portion 16 protruding toward the drum portion 13 and a cylindrical sleeve 17 formed on the inner peripheral side of the wall portion 16. Further, the throttle body 8 has a wall portion 18 protruding to the opposite side of the drum portion 13 and a sleeve 19 formed on the inner peripheral side of the wall portion 18.

  The shaft portion 12 includes a shaft portion 14 positioned above the valve portion 11 and a shaft portion 15 positioned below the valve portion 11 in FIG. A bush 20 that is divided into two on the surface along the axis of the shaft portion 12 is provided on the outer periphery of the shaft portion 14, and the shaft portion 14 is inserted into the sleeve 17 of the throttle body 8 together with the bush 20. The diameter of the bush 20 that surrounds the shaft portion 14 is larger than the dimension of the valve portion 11 (the length of one side of a substantially square), and the diameter of the shaft portion 15 is set smaller than the dimension of the valve portion 11.

  The shaft portion 15 located below in FIG. 1 is inserted into the sleeve 19. The end portion of the shaft portion 15 protrudes from the sleeve 19. A washer 21 is passed through the protruding portion, and a stop ring 22 is further fitted. The washer 21 and the stop ring 22 fix the throttle valve body 10 so as not to come out of the throttle body 8.

  The valve part 11 is covered with an elastic part 23. The elastic part 23 functions as a seal member that covers the valve part 11 and maintains an airtight space between the shaft part 12 and the throttle body 8. The elastic portion 23 includes annular portions 24 and 25 extending from the valve portion 11 to the shaft portion 14 and the shaft portion 15, respectively. The peripheral edges of the annular portions 24 and 25 are formed in a corrugated shape so that the portion in contact with the throttle body 8 is easily bent and has good adhesion to the throttle body 8. The elastic part 23 is preferably formed from an elastic polymer. Elastic polymers are materials with excellent chemical resistance. The elastic portion 23 is added to the throttle valve body 10 that is resin-molded by molding. That is, the elastic part 23 is integrated with the throttle valve body 10 by double molding. In the double molding, the throttle valve body 10 is first formed by resin injection molding. A mold that secures a space for injecting the elastic polymer forming the elastic portion 23 is disposed around the throttle valve body 10 and the elastic polymer is injected into the mold. As a result, the elastic portion 23 is attached to the throttle valve body 10.

  The elastic portion 23 having a corrugated peripheral edge provides a good seal between the shaft portion 12 and the throttle body 8, and the valve portion 11 and the throttle body 8 when the valve portion 11 abuts against the step of the throttle body 8. The sealing property is also improved.

  4 is a top view of the throttle valve body 10 (viewed from the drum 13 side), FIG. 5 is a sectional view of the outer cover 28, and FIG. 6 is a side view of the torsion spring 27. 4, 5, and 6 are referred to in conjunction with FIG. 1. The torsion spring 27 is a compression coil spring, and both ends 271 and 272 are bent so as to be directed toward the inside of the coil diameter D of the spring, preferably the center of the coil diameter D, as shown in FIG. The torsion spring 27 is interposed between the drum portion 13 and the outer cover 28 that covers the cylindrical wall portion 16 of the throttle body 8. A concave portion 26 is formed on the upper side of the drum portion 13, that is, on the side far from the valve portion 11. The drum portion 13 is provided with a slit 131, and the end portion 271 of the torsion spring 27 is fitted into the slit 131 to stop the rotation. A groove 29 is formed along the outer periphery of the drum portion 13 of the throttle valve body 10, and a throttle cable (not shown) is attached by being guided by the groove 29.

  The other end of the coil of the torsion spring 27 is received by an external cover 28 serving as a spring holder that covers the top of the wall 16. The outer cover 28 is provided with a cylindrical portion 281 that guides the torsion spring 27 to prevent buckling, and the cylindrical portion 281 is provided with a slit 284. The end portion 272 of the torsion spring 27 is fitted into the slit 284 and the rotation is stopped.

  The torsion spring 27 is set so as to urge the valve portion 11 in the throttle fully closed direction. When the throttle cable (not shown) is pulled, the shaft portion 12 rotates in the direction opposite to the urging direction by the torsion spring 27. And the throttle is opened.

  An annular groove 31 for fitting an O (O) ring 30 as a seal member for dust seal is provided on the lower surface of the outer cover 28, and the outer cover 28 and the wall portion 16 covered on the wall portion 16 are provided. The upper end portion is sealed by the O-ring 30.

  FIG. 7 is a view showing an engaging portion of the outer cover and the throttle body. In the figure, two protrusions 32 are provided on the outer peripheral surface of the wall 16. On the other hand, the outer cover 28 is provided with a hook 33 that engages with the protrusion 32. The hook portion 33 has a bent shape including a hanging portion 331 and a horizontal portion 332 that extends from the hanging portion 331 and wraps around the lower side of the protruding portion 32.

  When the outer cover 28 is fixed to the wall portion 16, first, the outer cover 28 is put on the wall portion 16 from above at a position where the hook portion 33 does not interfere with the projection portion 32. The O-ring 30 is disposed in the annular groove 31 in advance. When the outer cover 28 is put on the wall portion 16, the outer cover 28 is turned in the extending direction R of the horizontal portion 332, and the horizontal portion 332 is engaged with the lower surface of the protruding portion 32. The operation for turning the outer cover 28 relative to the wall portion 16 is performed in a state where the O-ring 30 is compressed by pressing the outer cover 28 against the end surface of the wall portion 16. By such an operation, when the hook portion 33 is hooked on the projection portion 32 and the pressing force against the outer cover 28 is released, an elastic force is applied to restore the shape of the O-ring 30, and the outer cover 28, the wall portion 16, The hook 33 and the protrusion 32 are engaged with each other in a state where the sealing state is secured.

  A control unit 34 made of a resin material is attached to the wall 18. The control unit 34 includes a throttle sensor 35, a connecting shaft 36, a control board 37, and a block or housing incorporating an IACV mechanism (not shown). The control board 37 holds a circuit having at least a function for processing the detection output of the throttle sensor 35 and controlling the IACV mechanism (this circuit can be configured by a microcomputer). The housing of the control unit 34 includes a first portion 341 and a second portion 342. The first portion 341 supports a connecting shaft 36 that connects the shaft portion 12 of the throttle valve body 10 and the throttle sensor 35. The first portion 341 includes conduits 40 and 41 that connect idle ports 38 and 39 provided on the wall 18 to an IACV mechanism, that is, an automatic throttle valve mechanism. The second portion 342 is coupled to the first portion 341 by a plurality of set screws 42. The second portion 342 accommodates a throttle sensor 35 and a control board 37, and an IACV mechanism (not shown).

  A cap 43 is put on the second portion 342. The cap 43 is put on an annular portion 343 protruding from the second portion 342, and a claw 344 formed in a part of the annular portion 343 is engaged with and fixed to the hole 431 on the cap 43 side.

  The end portion of the wall portion 18 has a flange 181, and the first portion 341 has a plurality of claws 345 that are caught by the flange 181. The claw 345 has a shape along the end surface of the flange 181 and is hooked on the jaw 182 of the flange 181 to couple the control unit 34 to the throttle body 8. Since the housing of the control unit 34 and the throttle body 8 are formed of a resin material, when the control unit 34 is pressed against the flange 181, the claw 345 is expanded, and when the control unit 34 is further pressed, the tip of the claw 345 is pushed. The hook is caught on the jaw 182 of the flange 181 and is kept engaged by its elasticity.

  When the throttle valve body 10 is assembled to the throttle body 8, the throttle valve body 10 is inserted into the throttle body 8 from the shaft portion 15 side with respect to the sleeve 17. Then, after the shaft portion 15 is passed through the sleeve 19 and its end portion is protruded from the sleeve 19, the washer 21 and the stop ring 22 are fitted into the outer periphery of the end portion of the shaft portion 15. The throttle valve body 10 can be assembled to the throttle body 8 from one direction by making the diameter of the bush 20 larger than the dimension of the valve part 11 and the diameter of the shaft part 15 smaller than the dimension of the valve part 11. ing. However, the shaft portion 12 is not limited to this shape, and the diameter of the shaft portion 14 can be increased in the same manner as the bush 20 to eliminate the need for the split-type bush 20. Even in this case, the throttle valve body 10 can be assembled to the throttle body 8 from one side.

  In the throttle valve body 10, the peripheral portion of the elastic portion 21 is pressed against the throttle body 8 by the repulsive force of the torsion spring 27, and a reliable sealing performance is obtained. Further, if the stop ring 22 is fitted in the shaft portion 12 in a state where a thrust load is applied in a direction directed from the shaft portion 14 side to the shaft portion 15 side, higher sealing performance can be obtained.

  8 is an exploded perspective view of a throttle valve device according to a second embodiment of the present invention, FIG. 9 is a cross-sectional view of the throttle valve device according to the second embodiment, and FIG. 10 is a side view of the same. Indicates the same or equivalent part. 8 to 10, the throttle valve device includes a throttle body 8, a throttle valve main body 10 inserted into the throttle body 8, and the throttle valve main body 10 in the direction of arrow R <b> 1, that is, the throttle valve closing side. And a torsion spring 27 that urges the valve body 10 in the direction of arrow T, that is, the direction in which the throttle valve body 10 is pushed into the throttle body 8. The torsion spring 27 includes a coil portion 275 and an overhang portion 276 formed at one end of the coil portion 275 by bending. The other end of the coil portion 275 is formed with a locking portion 277 bent toward the center of the coil diameter.

  When disassembled, the torsion spring 27 freely expands as indicated by reference numeral 27a in FIG. 9, and when assembled, it is compressed to the state indicated by reference numeral 27 in FIG. That is, the coil portion 275 of the torsion spring 27 is pushed into the throttle valve body 10 and stored when the assembly is completed. The overhanging portion 276 of the torsion spring 27 protrudes from the throttle valve body 10, and both ends 276 a and 276 b are engaged with grooves 84 and 85 of stays 82 and 83 as spring holding portions provided in the throttle body 8. .

  An annular groove 121 extending from the drum portion 13 to the shaft portion 14 is formed in the throttle valve body 10, and the coil portion 275 of the torsion spring 27 is accommodated in the annular groove 121. The bent locking portion 277 of the coil portion 275 fits into a slit 122 formed so as to slit the drum portion 13 and the shaft portion 14 of the throttle valve body 10 in the diametrical direction.

  As shown in FIG. 10, a throttle cable 50 is hung on the drum portion 13. One end portion of the throttle cable 50 is fixed to the drum portion 13 with a pin 51 fitted into the pin hole 133 of the drum portion 13. The throttle cable 50 is hung on the outer periphery of the drum portion 13 along the groove 29 and is extended into the guide tube 52.

  When the torsion spring 27 is assembled to the throttle valve body 10, the coil portion 275 is compressed after the torsion spring 27 is fitted into the slit 122 with the engaging portion 277 at the end of the coil portion 275. If the overhanging portion 276 is pushed close to the same level as the grooves 84 and 85, the torsion spring 27 is twisted in the direction of the arrow R1 so that both ends 276a and 276b of the overhanging portion 276 have the grooves 84 and 85 of the stays 82 and 83. Rotate until it passes. At this position, the overhanging portion 276 is returned in the direction opposite to the arrow R1 and fitted into the grooves 84 and 85.

  According to the second embodiment, the torsion spring 27 has spring holding portions (stays) 82 and 83 that engage with both ends 276a and 276b of the projecting portion 276 integrally formed with the throttle body. There is no need to provide a spring catch. Further, one end of the torsion spring 27 is equally supported by the throttle body 8 at both ends of the projecting portion 276 and the other end is supported by the center of the shaft portion 12 of the throttle valve body 10. Uneven load with respect to the extending direction of the shaft portion 12 is not applied.

It is sectional drawing of the throttle valve apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the intake system containing the throttle valve apparatus which concerns on one Embodiment of this invention. It is a front view of a throttle valve device concerning one embodiment of the present invention. It is a top view of a throttle valve body. It is sectional drawing of the cover which accommodates a torsion spring. It is a side view of a torsion spring It is an external view which shows the engaging part of an external cover and a throttle body. It is a disassembled perspective view of the throttle valve apparatus which concerns on 2nd Embodiment of this invention. It is sectional drawing of the throttle valve apparatus which concerns on 2nd Embodiment. It is a side view of the throttle valve device concerning a 2nd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 2 ... Intake port, 4 ... Intake pipe, 7 ... Air cleaner case, 8 ... Throttle body, 10 ... Throttle valve body, 11 ... Valve part, 12 ... Shaft part, 13 ... Drum part, 16 ... Cylindrical shape Wall part 27 ... Torsion spring 28 ... Cover 82, 83 ... Stay (spring holding part)

Claims (3)

A throttle valve main body comprising a butterfly valve portion, a shaft portion projecting from the butterfly valve portion on both sides, and a drum portion enlarged at one end of the shaft portion to transmit an operating force for throttle adjustment from the outside; A throttle valve device for an internal combustion engine having a throttle body that accommodates the throttle valve body in a state in which the shaft portion is rotatably supported;
A cover that covers the throttle valve body and the throttle body from the drum portion side;
A compression coil type torsion spring interposed between the drum portion and the cover and biasing the drum portion in the closing direction of the butterfly valve portion;
The coil portion of the torsion spring is disposed concentrically with the throttle valve main body, and is engaged with the cover and the drum portion at both ends bent inward of the coil diameter of the torsion spring to prevent rotation. Throttle valve device characterized by   The throttle valve device according to claim 1, wherein a slit is formed in the cover and the drum portion along a diameter of the drum portion so as to fit both ends of the torsion spring. A throttle valve main body comprising a butterfly valve portion, a shaft portion projecting from the butterfly valve portion on both sides, and a drum portion enlarged at one end of the shaft portion to transmit an operating force for throttle adjustment from the outside; A throttle valve device for an internal combustion engine having a throttle body that accommodates the throttle valve body in a state in which the shaft portion is rotatably supported;
An annular groove formed concentrically with the shaft portion and having a depth extending from the drum portion to a shaft portion adjacent to the drum portion;
A slit formed along the diameter of the drum portion and the shaft portion in the inner portion of the annular groove;
In the throttle body, disposed around the drum portion, a spring holding portion having a groove in which the throttle closing direction is opened and the throttle opening direction is closed;
A compression coil type comprising a coil portion, one end portion bent inward of the coil diameter of the coil portion, and the other end portion bent so as to protrude from the coil portion in a plurality of protruding directions outward in the coil diameter. And a torsion spring
One end portion of the torsion spring is inserted into the slit, the coil portion is inserted into the annular groove, and the projecting portion of the other end portion is twisted in the throttle closing direction in the state where the throttle valve body is twisted. A throttle valve device which is inserted into a groove of a spring holding portion.

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