JP6437864B2 - Intake flow control device - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention relates to an intake flow control device, in particular, a throttle body having an intake passage that forms part of an intake passage connected to a combustion chamber of an internal combustion engine, and is capable of opening and closing the intake passage rotatably supported by the throttle body. A throttle valve, a tumble valve disposed in an intake passage downstream of the throttle valve and rotatably supported by the throttle body, and a valve spring for urging the throttle valve and the tumble valve in a valve closing direction, respectively And a pair of intake passages that comprise a stopper portion that can hold the throttle valve and the tumble valve in their closed positions against the urging force of the valve springs, and the tumble valve divides the intake flow downstream of the stopper portion. The present invention relates to an intake flow control device capable of opening and closing one of the portions.

  Conventionally, in such an intake flow control device, a tumble lever that rotates integrally with a manually operated throttle valve and a tumble lever that rotates integrally with the tumble valve are tumbled in the same rotational direction with respect to the throttle lever. A device provided with an interlocking mechanism capable of interlockingly rotating the lever is known, for example, as described in Patent Document 1 below. In this conventional device, the strength of the tumble flow (longitudinal vortex flow) in the combustion chamber can be adjusted by opening and closing the one intake passage portion with a tumble valve interlocked with the throttle valve.

JP 2014-199035 A

  However, in the above-described conventional apparatus, the interlocking mechanism for interlocking the tumble valve with the throttle valve is constituted by a link mechanism including a plurality of links mechanically interlockingly connecting the two valves.

  Further, in this conventional device, particularly in the low opening range of the throttle valve, the tumble valve is closed to strengthen the tumble flow and stabilize the low load operation of the internal combustion engine, and after the throttle valve is opened to some extent, the tumble valve is opened. The valve is started to open. Therefore, it is necessary to specially incorporate a lost motion mechanism for holding the tumble valve in the closed state in the low opening range of the throttle valve in the interlocking mechanism composed of a combination of a plurality of links.

  Accordingly, there is a problem that the structure of the interlocking mechanism becomes complicated and large as a whole, resulting in an increase in cost and size of the apparatus, a decrease in assembly workability, and the like.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide the intake flow control device that can solve the above-described problems at once with a simple structure.

In order to achieve the above object, the present invention provides a throttle body having an intake passage that constitutes a part of an intake passage connected to a combustion chamber of an internal combustion engine, and an intake passage that is rotatably supported by the throttle body. Throttle valve, a tumble valve that is disposed in the intake passage downstream of the throttle valve and is rotatably supported by the throttle body, and a valve that urges each of the throttle valve and the tumble valve in the valve closing direction. A pair of springs and stoppers that can hold the throttle valve and the tumble valve in their closed positions against the urging force of the valve springs, and the tumble valve divides the intake air flow downstream of the pair of springs. An intake air flow control device capable of opening and closing one of the intake passage portions, a throttle lever that rotates integrally with a manually operated throttle valve, and an integral with a tumble valve An interlocking mechanism capable of interlockingly rotating the tumble lever in the same rotation direction with respect to the throttle lever is interposed between the rotating tumble lever, and the interlocking mechanism is a drive unit that rotates integrally with the throttle lever. And a follower that can move toward and away from the drive unit and rotate integrally with the tumble lever, and in a valve opening process in which the throttle valve rotates in the valve opening direction from its closed position, In the middle of rotation, the driving unit starts to contact the driven unit on one side of a virtual plane including the rotation axis of both valves, and the driven unit is pushed by the driving unit by the contact, so that the tumble valve is moved from the closed position. is intended to rotate to the open side, the tumble valve includes a valve shaft rotatably supported in the throttle body extending across the intake passage, rotates integrally therewith in its valve shaft A plate-shaped valve body to be coupled, and a notch that allows the intake air to flow on the opposite side of the valve body across the valve shaft when the tumble valve is in the closed position, Contact between the drive unit and the driven unit during the valve opening process between the butterfly valve body of the throttle valve and the valve shaft of the tumble valve when in the fully open position in the direction along the intake passage The first feature is that the starting point is located.

Furthermore, in addition to the first feature, the present invention provides a valve opening angle of the throttle valve in the process of opening the tumble valve in conjunction with the throttle valve due to mutual contact between the driving unit and the driven unit. the ratio of the time rate of change of the valve opening angle of the tumble valve with respect to time rate of change, than the valve opening initial tumble valve, that is subsequently tumble valve is formed larger such shape when further opened second It is characterized by.

The present invention, in addition to the first or second feature, the follower has the tumble lever which is fixed to the valve shaft of the tumble valve as an insert part, to be molded of a synthetic resin 3 It is characterized by.

Furthermore, the present invention provides the valve body of the tumble valve on the peripheral wall of the intake passage that functions as the stopper when the tumble valve rotates to the closed position in addition to the first or second feature. A fourth feature is that the outer peripheral edge of each of the two is held in a closed position.

  According to the first feature of the present invention, the interlocking mechanism for interlockingly rotating the tumble lever in the same rotational direction as the throttle lever can be contacted with and separated from the driving part that rotates integrally with the throttle lever. And a driven portion that rotates integrally with the tumble lever, and in the valve opening process in which the throttle valve rotates in the valve opening direction from its closed position, the drive portion is moved to the driven portion during the rotation. Since the tumble valve rotates from the closed position to the open side when the driven part is pushed by the drive part due to the contact, the tumble valve rotates from the closed position to the open side. The tumble valve can be accurately opened in conjunction with the opening operation of the throttle valve without mechanically interlocking and connecting with a complicated link mechanism. In addition, the tumble valve is interlocked with the throttle valve without using a complicated structure of the lost motion mechanism until the drive unit comes into contact with the driven unit during the opening of the throttle valve (that is, in the low opening range of the throttle valve). Therefore, the tumble flow in the combustion chamber can be strengthened and the low-load operation of the internal combustion engine can be stabilized while simplifying the structure and reducing the size of the interlocking mechanism. As a result, since the overall structure of the interlocking mechanism can be greatly simplified and reduced in size as a whole, it can greatly contribute to cost reduction, downsizing, and improvement in assembly workability of the apparatus.

In addition , contact between the butterfly valve body of the throttle valve and the valve shaft of the tumble valve in the direction along the intake passage begins to contact the drive unit and the driven unit during the throttle valve opening process. Since the point is located, an imaginary line connecting the rotation axis and the contact start point (that is, the arm of the moment that the follower receives from the drive unit) is seen on the projection plane orthogonal to the rotation axis of the tumble valve. It is arranged so as to tilt toward the drive unit side (throttle valve shaft side) with respect to the virtual plane. As a result, the effective length of the arm of the moment can be secured long enough to prevent the driven portion from extending long in the direction away from the virtual plane, so that the interlocking mechanism is prevented from becoming bulky in the same direction. It is possible to reduce the size of the interlocking mechanism, and to reduce the contact point load between the drive unit and the driven unit, thereby effectively suppressing the wear of the contact unit. In addition, since the throttle valve and the tumble valve are arranged close to each other in the direction along the intake passage when they are fully opened, the intake flow is effectively prevented from being disturbed between the two valves, and the intake resistance is reduced. It can contribute to the reduction of.

According to the second aspect of the present invention, the driving unit and the driven unit are configured to change with respect to the time change rate of the valve opening angle of the throttle valve in the process of opening the tumble valve in conjunction with the throttle valve due to mutual contact between them. Since the ratio of the time change rate of the opening angle of the tumble valve is formed so as to become larger when the tumble valve is further opened after the initial opening of the tumble valve, the opening process of the throttle valve When the drive unit starts to contact the driven unit, the rate of change in the opening angle of the tumble valve is relatively small, and the impact at the time of the contact can be reduced. Generation can be effectively suppressed. On the other hand, when the drive part moves away from the driven part and the tumble valve engages with the stopper part in the closing process of the throttle valve, the rate of change in the opening angle of the tumble valve becomes relatively small, and the engagement with the stopper part becomes difficult. The impact at the time of joining can be reduced, and thereby, wear damage and contact noise generation of the engaging portion can be effectively suppressed.

According to a third aspect of the present invention, the driven unit, a tumble lever which is fixed to the valve shaft of the tumble valve as an insert part, because they are molded by the synthetic resin, while accurately resin molding follower, Simultaneously with the molding, it can be combined with the tumble lever, contributing to cost savings and mass productivity improvement.

According to the fourth aspect of the present invention, when the tumble valve rotates to the closed position, the outer peripheral edge of the valve body of the tumble valve is held in the closed position by contacting the peripheral wall of the intake passage. Therefore, it is not necessary to provide a special valve closing stopper for the tumble valve outside the intake passage on the throttle body.In other words, the peripheral wall of the intake passage also serves as the valve closing stopper, reducing the number of parts and contributing to cost savings. can do.

The side view which shows one Embodiment of the intake flow control apparatus which concerns on this invention, and the internal combustion engine connected to this Plan sectional view (sectional view taken along line 2-2 in FIG. 1) and partially enlarged view of the intake air flow control device Longitudinal sectional view (sectional view taken along line 3-3 in FIG. 2), partial enlarged view and partial lateral sectional view of the intake air flow control device Partially cutaway side view of the intake flow control device for explaining the interlocking mode of the tumble valve / throttle valve

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  First, in FIG. 1, an intake air flow control device A for controlling an intake air flow to be introduced into an internal combustion engine E for a motorcycle includes a metal throttle body B and an intake air having a substantially circular cross section that passes through the throttle body B. The intake path 2 is formed in the cylinder head Ech of the internal combustion engine E, and the upstream end of the intake port 3 that opens to the combustion chamber 1 is directly or via the intake pipe 4. Connected. The downstream end of the intake port 3, that is, the intake valve port, is opened and closed by an intake valve Vi that opens and closes in conjunction with the rotation of a crankshaft (not shown). The intake pipe 4 or the cylinder head Ech is provided with a fuel injection device (not shown) that injects fuel to be mixed with intake air toward the intake port 3 or the combustion chamber 1. Thus, a series of passages extending over the intake passage 2 and the intake port 3 constitute an intake passage I that is continuous with the combustion chamber 1 of the internal combustion engine E. In FIG. 1, the throttle body B and the internal combustion engine E are drawn at different scales.

  Referring also to FIGS. 2 and 3, the intake flow control device A includes a throttle valve V1 that is pivotally supported by the throttle body B so as to open and close the intake passage 2, and more than the throttle valve V1. A tumble valve V2 as a flow control valve disposed in the intake passage 2 on the downstream side and rotatably supported by the throttle body B, and the throttle valve V1 and the tumble valve V2 are each elastically energized in the valve closing direction. First and second valve springs SP1 and SP2, and first and second stopper portions ST1 and ST2 that can hold the throttle valve V1 and the tumble valve V2 in their closed positions against the biasing force of the valve springs SP1 and SP2. ST2 is provided.

  The throttle valve V1 has a throttle valve shaft j1 extending so as to cross the intake passage 2 and a generally disc-shaped (strictly speaking elliptical) valve coupled to the throttle valve shaft j1 so as to rotate integrally therewith. A main body b1. The intermediate portion of the valve body b1 is inserted into a slit formed in the intermediate flat portion of the throttle valve shaft j1, and is detachably coupled to the intermediate flat portion of the throttle valve shaft j1 with a plurality of screws 31 penetrating the valve body b1. The Between the outer periphery of both ends of the throttle valve shaft j1 and the bearing hole of the throttle body B that supports the throttle valve shaft j1 rotatably, annular seal members SE1 and SE1 that seal the respective portions are interposed.

A metal throttle lever L1 is coupled to one end of the throttle valve shaft j1 facing the outside of the throttle body B so as to rotate integrally. The throttle lever L1 is integrally connected to the lever body 8 and a circular drum-shaped lever body 8 having a groove 8g on the outer periphery on which one end of each of the pair of throttle wires w1, w2 can be wound in two different directions. and a drive unit D extending tumble lever L 2 side to be described later Te. Between the throttle lever L1 and the throttle body B, the valve spring SP1 made of a torsion coil spring for biasing the throttle lever L1 in the valve closing direction is interposed.

  One terminal of each throttle wire w1, w2 is coupled to the lever body 8, and the other terminal is coupled to a throttle drum integral with an accelerator grip of a motorcycle (not shown). Therefore, the throttle valve V1 can be opened and closed through the throttle wires w1 and w2 by a manual rotation operation on the accelerator grip.

  Further, the lever body 8 has a locking projection 8s that regulates the valve closing position of the throttle valve V1 in an adjustable manner in cooperation with the first stopper portion ST1 with the adjusting screw 9 provided on the throttle body B. Is projected. That is, when the throttle valve V1 is closed to the valve closing position, the locking projection 8s engages with the adjustment screw 9 of the first stopper part ST1, so that the throttle valve V1 is made elastic by the valve spring SP1. In contrast, the minimum valve opening is maintained. Even at this minimum valve opening, the intake passage 2 is not completely closed, and the minimum intake amount required for low-load operation of the internal combustion engine E can be secured through the throttle valve V1.

  On the other hand, the tumble valve V2 opens and closes one of the pair of upper and lower intake passage portions 5 and 6 (the lower intake passage portion 6 in the illustrated example) that divides the intake flow downstream of the tumble valve V2. The pair of upper and lower intake passage portions 5 and 6 are partition plates 7 that vertically pass through the intake pipe 4 and the intake port 3, and each of the intake passages I on the downstream side of the tumble valve V2 is divided into upper and lower portions, respectively. It is defined in a circle.

  When the tumble valve V2 is in the predetermined closed position and closes the lower intake passage portion 6, the intake air flow that passes through the throttle valve V1 and flows through the intake passage 2 flows through the upper intake passage portion 5 by the tumble valve V2. It is controlled to go to the combustion chamber 1. Thereby, the flow velocity of the intake air flowing into the combustion chamber 1 can be increased, and the tumble flow T (vertical vortex flow) of the intake air generated in the combustion chamber 1 can be strengthened. Further, by dividing the intake passage I on the downstream side of the tumble valve V2 up and down, the intake flow is controlled to flow only through the upper intake passage portion 5 by the tumble valve V2 and heads toward the combustion chamber 1. Thereby, the tumble flow T of the intake air generated in the combustion chamber 1 can be further strengthened.

  On the other hand, when the tumble valve V2 is in the fully open position and the lower intake passage portion 6 is sufficiently opened, the intake air flow that passes through the throttle valve V1 and flows through the intake passage 2 is not hindered by the tumble valve V2. It also flows to the intake passage portion 6 and travels toward the combustion chamber 1. Thus, the strength of the tumble flow T can be adjusted by opening and closing the tumble valve V2.

  Next, a specific structure of the tumble valve V2 and a support structure to the throttle body B will be described.

  The tumble valve V2 is a metal tumble valve shaft j2 that extends across the intake passage I on the downstream side of the throttle valve V1, and a metal plate that is coupled to the tumble valve shaft j2 so as to rotate integrally therewith. Valve body b2. The valve body b2 is formed in a substantially semicircular shape (strictly speaking, a substantially semielliptical shape), and the base 20k of the valve body b2 corresponding to the position of the semicircular chord is a tumble valve shaft. It extends linearly along j2 and is in close proximity to the upstream edge of the partition plate 7. That is, the valve body b2 has a cutout portion K formed by cutting a substantially circular butterfly valve body half (that is, in a semicircular shape) at the outer end of the base portion 20k. Even when the tumble valve V2 is in the closed position and closes the lower intake passage portion 6, the notch K is located on the opposite side of the valve body b2 with the tumble valve shaft j2 interposed therebetween (that is, the upper intake passage portion 5). Allow distribution of intake air.

  The intermediate portion of the tumble valve shaft j2 is formed flatter than both end portions, and a slit for inserting the base portion 20k of the valve body b2 is provided in the flat intermediate portion. The base portion 20k is detachably coupled to the flat intermediate portion of the tumble valve shaft j2 with a plurality of screws 32 penetrating therethrough. The screw insertion hole formed in the base portion 20k and through which the screw 32 passes is a hole with a diameter slightly larger than the screw shaft portion of the screw 32. Therefore, the tumble valve shaft j2 is assembled to the throttle body B as described later. After that, when the valve body b2 is screwed to the tumble valve shaft j2, the arc-shaped outer peripheral edge portion 20c of the valve body b2 is brought into precise contact with the lower half of the peripheral wall of the intake passage 2 (ie, the second stopper portion ST2). To get.

  Further, one end portion of the tumble valve shaft j2 is rotatably supported by a first bearing portion Bb1 provided on one side portion of the throttle body B, and is attached to a strip-shaped metal tumble lever L2 outside the throttle body B. Combined together. Between the tumble lever L2 and the throttle body B, a valve spring SP2 composed of a torsion coil spring that biases the tumble lever L2 in the valve closing direction is interposed. The other end portion of the tumble valve shaft j2 is rotatably supported by a second bearing portion Bb2 provided on the opposite side of the throttle body B from the first bearing portion Bb1 across the intake passage I.

  Next, the structure of these bearing portions Bb1 and Bb2 will be described mainly with reference to FIG. The first bearing portion Bb1 is connected to a first bearing hole 11 that rotatably supports one end portion of the tumble valve shaft j2, and an end portion of the first bearing hole 11 on the tumble lever L2 side via a step portion s. A mounting hole 13 having a diameter larger than that of the first bearing hole 11 is formed. Between the first bearing hole 11 and the outer periphery of the one end portion of the tumble valve shaft j2, it is fitted into an annular seal groove provided in any one of them (the first bearing hole 11 in the illustrated example), and the space therebetween An annular seal member SE2 for sealing is interposed.

  A flange portion 14 projecting from the outer periphery of one end portion of the tumble valve shaft j2 is inserted into the mounting hole 13 so that one side surface (that is, the inner side surface) of the flange portion 14 faces the stepped portion s. The flange portion 14 is formed in a C-shape with an appropriate material different from the metal tumble valve shaft j2 in the illustrated example, for example, a synthetic resin, and the tumble valve shaft j2 is made of its elastic expanding deformation. It is fitted into the annular groove 15 on the outer periphery of the one end. The flange portion 14 may be formed of a pair of semicircular arc-shaped flange halves and fitted or fixed to the annular groove portion. Alternatively, the flange portion 14 may be attached to the outer periphery of one end portion of the tumble valve shaft j2. May be formed integrally.

  Further, a cylindrical shape for positioning the tumble valve shaft j2 in the axial direction with respect to the throttle body B and retaining it on the outer periphery of one end portion of the tumble valve shaft j2 on the other side surface (that is, the outer surface) of the flange portion 14 is provided. A collar C is disposed so as to surround the outer periphery of the one end. The collar C is press-fitted into the mounting hole 13 from the outside in the axial direction so that the flange portion 14 is sandwiched between the inner end Ci of the collar C and the stepped portion s. The outer end Co of the collar C is integrally provided with a stopper flange Cos that engages with the outer end surface 16 of the first bearing portion Bb1 where the mounting hole 13 opens. The stopper flange Cos and the outer end surface 16 By this engagement, the limit position for press-fitting the collar C into the mounting hole 13 is accurately defined.

Thus, in the set state in which the collar C is press-fitted into the mounting hole 13, the axial distance between the inner surface of the stopper flange Cos of the collar C (that is, the outer end surface 16 of the first bearing portion Bb1) and the stepped portion s is set. When s1, the axial width of the flange portion 14 is s2, and the axial distance between the inner end Ci of the collar C and the inner surface of the stopper flange Cos is s3,
s1> (s2 + s3)
The size of each part is set so as to satisfy this relationship.

  Accordingly, even after the collar C is press-fitted into the mounting hole 13, the flange portion 14 is axially positioned between the inner end Ci of the collar C and the stepped portion s in a predetermined play range corresponding to s1− (s2 + s3). Can move to. As a result, the flange portion 14, that is, the tumble valve shaft j2 can be slightly slid relative to the throttle body B in the axial direction by the amount of play.

  Further, a small-diameter shaft portion 19 having a flat portion for preventing rotation on the outer periphery is integrally formed at the tip end of one end portion of the tumble valve shaft j2. The small-diameter shaft portion 19 is fitted into a locking hole formed in the tumble lever L2 so as to have substantially the same cross-sectional shape as that, and the end surface of the small-diameter shaft portion 19 is hit with a caulking tool. The tumble lever L <b> 2 is caulked and fixed 40 to the small diameter shaft portion 19 by being plastically deformed radially outward. After the caulking and fixing 40, on the outer end surface of the collar C, the tumble lever L2 is viewed from the axially outward side of one end portion of the tumble valve shaft j2 (that is, viewed on the projection plane orthogonal to the tumble valve shaft j2). ) There are a plurality of portions 21 to 23 that do not overlap the tumble lever L2, and a press-fit load can be applied to the collar C through the portions 21 to 23 that do not overlap.

  In particular, in the present embodiment, before the tumble valve shaft j2 having the collar C and the flange portion 14 previously set on the outer periphery of the one end is assembled to the throttle body B, the tumble lever L2 is fixed to the one end of the tumble valve shaft j2. However, even after the caulking and fixing 40, the outer end surface of the collar C has a plurality of portions 21 to 23 that do not overlap with the tumble lever L2 as described above. The collar C can be press-fitted and fixed without difficulty in the mounting hole 13 without being obstructed by L2, and the assembly workability is good.

  In the illustrated example, the plurality of portions 21 to 23 that do not overlap the tumble lever L2 on the outer end surface of the collar C are triangular vertices 21p that surround the axis of the tumble valve shaft j2 when viewed from the projection plane orthogonal to the tumble valve shaft j2. Dispersed in at least three regions including ˜23p. For this reason, since it is possible to apply a press-fit load to the collar C through these portions 21 to 23 in a well-balanced manner, the collar C is attached to the mounting hole 13 in an appropriate press-fit posture that does not fall with respect to the axis of the tumble valve shaft j2. Can be press-fitted accurately.

  On the other hand, the second bearing portion Bb2 is composed of a second bearing hole 17 formed in a bag hole shape in the throttle body B so that one end is opened in the intake passage 2 and the other end is closed. The other end of the tumble valve shaft j2 is rotatably inserted into the bearing hole 17 from the intake passage I side. In the inserted state, a gap is formed between the bottom of the second bearing hole 17 and the other end surface of the tumble valve shaft j2.

Incidentally, the tumble valve V2 has the valve body b2 formed in a semicircular plate shape as described above, and when the tumble valve V2 rotates to a predetermined closed position, the valve body b2 is viewed from the tumble valve shaft j2. The minimum valve opening of the tumble valve V2 is defined by bringing only the arcuate outer peripheral edge 20c on one side into contact with the lower half of the peripheral wall of the intake passage 2 (that is, the second stopper portion ST2). Held in the closed position. Thus, the intake passage 2 peripheral wall of the throttle body B is, becomes to be combined in a closing stopper S T 2 for tumble valve V2, the closing stopper for tumble valve V2 in second outer air passage in the throttle body B Since there is no need to provide a special one, the number of parts can be reduced and the cost can be reduced. When the tumble valve V2 is in the closed position, the valve body b2 is disposed so as to be slightly inclined toward the intake upstream side with respect to a virtual plane orthogonal to the two intake passage axes.

  Further, a predetermined region that is continuous in the circumferential direction of the valve main body b2 across at least a virtual plane f ′ that is orthogonal to the tumble valve shaft j2 and passes through the center line of the intake passage I of the arcuate outer peripheral edge portion 20c of the valve main body b2. In the illustrated example (substantially the entire region of the arc-shaped outer peripheral edge portion 20c), the contact surface of the arc-shaped outer peripheral edge portion 20c with the lower half of the peripheral wall of the intake passage 2 (that is, the stopper portion ST2) has an arc-shaped cross section. Formed on the rounded surface r. Therefore, the valve body b2 is brought into contact with the circumferential wall of the intake passage only by the rounded surface r, so that the wear of the contact portion can be effectively suppressed, and the valve body b2 is galvanized by the circumferential wall of the intake passage. Therefore, it is possible to prevent the failure that becomes stuck and cannot be opened and effectively prevented. In addition, the arc-shaped outer peripheral edge portion 20c of the valve body b2 can strike the intake passage 2 circumferential wall in a well-balanced manner in a predetermined region that extends across the virtual plane f ′ in the circumferential direction of the valve body. The valve closing force received by the peripheral wall of the intake passage from the valve main body b2 is effectively present at the portion radially distant from the tumble valve shaft j2 axis (that is, the free end of the valve main body b2 and its peripheral portion). Since it can reduce, it is more effective for the abrasion suppression of the said contact part.

  Further, in the present embodiment, the valve body b2 of the tumble valve V2 is directed in a direction orthogonal to the plate surface thereof (particularly from one surface side facing the intake downstream side when the valve body b2 is closed to the other surface side facing the upstream side. It is formed by press punching with a pressing load in the direction. In this case, the rounded surface r is one surface side of the valve body b2 facing the downstream side of the intake air when the valve is closed during the punching process (that is, the side where the punch for punching first hits the plate-like workpiece in the stamping process). Thus, it is formed by a rounded surface called a so-called sagging surface that inevitably occurs in the entire peripheral portion of the valve body b2 including the arcuate outer peripheral edge portion 20c. As a result, a so-called sag surface inevitably generated at the outer peripheral edge of the valve body b2 on the one surface side of the valve body b2 during the press punching process can be used as it is as the R surface r. This eliminates the need for a special process for obtaining the cost, thereby reducing costs.

  Further, in the present embodiment, an interlocking mechanism M capable of mechanically rotating the tumble lever L2 in the same rotational direction with respect to the throttle lever L1 is interposed between the manually operated throttle lever L1 and the tumble lever L2. The

  The interlocking mechanism M includes a drive unit D that rotates integrally with the throttle lever L1, and a driven unit F that can contact and separate from the drive unit D and rotate integrally with the tumble lever L2. In the valve opening process in which the throttle valve V1 rotates in the valve opening direction from its closed position, the drive unit D moves the valves V1, V1 to the driven unit F as shown in FIG. The contact starts at a contact start point x on one side of the virtual plane f including the rotation axis of V2 (upward in FIGS. 1 and 4), and the driven portion F is pushed by the drive portion D by the contact, whereby the tumble valve V2 Rotates from the closed position to the open side. In particular, in the present embodiment, the drive portion D is constituted by a strip plate portion integrally connected to one side of the outer peripheral portion of the lever body 8 of the throttle lever L1, and the driven portion F has a diameter of the tumble valve shaft j2. It is composed of a synthetic resin or hard rubber molded portion integrally joined to the tip of the strip-shaped lever body 10 extending along the line. In addition, an anchor projection 10a for retaining is integrally formed at the tip of the lever main body 10.

In the present embodiment, the region Z between the butterfly valve body b1 of the throttle valve V1 and the valve shaft j2 of the tumble valve V2 when in the fully open position in the direction along the intake passage I (see FIG. 4B). ), The contact start point x between the driving part D and the driven part F in the process of opening the throttle valve V1 is located. In addition, the driving unit D and the driven unit F are tumbled with respect to the time change rate dα / dt of the valve opening angle α of the throttle valve V1 in the process of opening the tumble valve V2 in conjunction with the throttle valve V1 due to mutual contact therebetween. Ratio P of time change rate dβ / dt of valve opening angle β of valve V2, ie,
(Dβ / dt) / (dα / dt) has a shape that becomes larger when the tumble valve V2 is further opened after the initial opening of the tumble valve V2, that is, minimum at the initial opening of the tumble valve V2. The shape is set to be If this relationship is illustrated in FIG. 4 (B), when the tumble valve V2 is further opened after the ratio P1 of the initial opening of the tumble valve V2, that is, (dβ1 / dt) / (dα1 / dt). It is clear that the ratio P2, that is, (dβ2 / dt) / (dα2 / dt) is larger (that is, P2> P1).

  In setting the ratio P, in the present embodiment, as the valve opening angle β of the tumble valve V2 increases from the time when the drive unit D starts to contact the driven unit F in the process of opening the throttle valve V1, the throttle valve The drive part D and the driven part F are formed in such a shape that the time change rate dβ / dt of the valve opening angle β of the tumble valve V2 gradually becomes larger than the time change rate dα / dt of the valve opening angle α of V1. The As such a shape, in this embodiment, either one of the working surfaces of the driving unit D and the driven unit F facing each other so as to be able to come into contact with each other (the working surface of the driving unit D in the illustrated example) is both Inclination inclined toward the other side (the driven portion F in the illustrated example) of the virtual plane f including the rotation axis of the valves V1 and V2, and particularly toward the outer side opposite to the tumble valve body b2. And the other working surface (the working surface of the driven portion F in the illustrated example) is formed in an arc shape in a cross section viewed from a projection surface perpendicular to the rotation axis of the valves V1 and V2. Is done. In addition, the combination of the inclined surface and the arcuate surface, and the drive unit D and the driven unit F is set opposite to the illustrated example, that is, the action surface of the drive unit D is set to the arcuate surface and the action of the follower unit F is set. The surface may be formed as an inclined surface. The inclined surface is a flat surface in the illustrated example, but may be a gently curved surface.

  In the present embodiment, the driven portion F is molded with synthetic resin using the tumble lever L2 fixed to the valve shaft j2 of the tumble valve V2 as an insert part. Thereby, since the driven part F can be resin-molded with high accuracy and can be combined and integrated with the tumble lever L2 at the same time as the molding, cost saving and mass productivity can be improved.

  Next, the operation of this embodiment will be described. When the throttle valve V1 is in the closed position, the drive part D integrated with the throttle lever L1 is separated from the driven part F on the tumble valve V2 side as shown in FIGS. 1 and 4A. The valve V2 is held at a predetermined closed position where the arcuate outer peripheral edge 20c of the valve body b2 contacts the lower half of the peripheral wall of the intake passage 2 by the elastic force of the valve spring SP2. Therefore, in a low load operation state of the internal combustion engine E in which the throttle valve V1 is closed, for example, in an idling operation state, the intake flow that is throttled by the throttle valve V1 in the closed position and tries to pass through the intake passage 2 is generated by the tumble valve V2. Flow control is performed so that only the upper intake passage portion 5 flows, and the flow proceeds toward the combustion chamber 1. As a result, the flow velocity of the intake air flowing into the combustion chamber 1 can be increased, and the tumble flow T (vertical vortex flow) of the intake air generated in the combustion chamber 1 can be strengthened. Combustion of the air-fuel mixture in the chamber 1 can be stabilized.

Further, when the throttle valve V1 is gradually opened from this state, when the throttle valve V1 reaches a predetermined intermediate opening, the drive part D starts to contact the driven part F as shown in FIG. When the driven portion F is pushed by the driving portion D by the contact, the tumble valve V2 rotates from the closed position to the open side in conjunction with the throttle valve V1. Thus, from the middle of opening of the throttle valve V1, the tumble valve V2 is also opened, and the intake air flows through not only the upper intake passage portion 5 but also the lower intake passage portion 6, and finally. the throttle valve V1 and tumble valve V2 as shown in FIG. 4 (C) are both fully open position. Therefore, the intake air is efficiently guided to the combustion chamber 1 in the high opening range of the throttle valve V1, and the intake efficiency in the medium load or high load operation region of the internal combustion engine E is increased. In this case, even if the tumble flow T of the intake air generated in the combustion chamber 1 is weakened, a sufficient intake amount is secured in the combustion chamber 1 for medium load or high load operation, and the internal combustion engine E is output at medium output or It can be operated without any problems in high output.

Thus, according to the present embodiment, the throttle valve V1 can be opened even if the throttle lever L1 and the tumble lever L2 are not mechanically interlocked with a complicated link mechanism as in the conventional device. In conjunction with this, the tumble valve V2 can be accurately opened. Moreover (in other words a low opening range of the throttle valve V1) until the drive unit D in the middle opening of the throttle valve V1 is brought into contact with the driven unit F, without using a structure complicated lost motion mechanism, a tumble valve V 2 because that can be kept in closed position without interlocked with the throttle valve V 1, while achieving structural simplification and size reduction of the interlocking mechanism M, it is possible to enhance the intake tumble flow T in the combustion chamber 1. In this way, in the present embodiment, the overall structure of the interlocking mechanism M can be greatly simplified and reduced in size, so that the intake flow control device A can be reduced in cost, reduced in size, and improved in assembly workability.

Furthermore, in the present embodiment, the region between the butterfly valve body b1 of the throttle valve V1 and the valve shaft j2 of the tumble valve V2 when in the fully open position in the direction along the intake passage I (reference numeral in FIG. 4B). The drive unit D and the driven unit F are arranged so that the contact start point x between the drive unit D and the driven unit F in the process of opening the throttle valve V1 is located at Z). According to this arrangement, when viewed on a projection plane orthogonal to the rotation axis of the tumble valve V2 (ie, the valve axis j2 axis), an imaginary line (that is, the driven line) connecting the rotation axis and the contact start point x. the moment arm of part F receives from the driving unit D) becomes the arrangement being tilted relative to a virtual plane f containing the axis of rotation of the dual valve V1, V2 to the driving unit D side (i.e. the throttle valve shaft j 1 side).

  Accordingly, the effective length of the arm of the moment can be secured sufficiently long while suppressing the driven portion F from extending in a direction away from the virtual plane f, so that the interlocking mechanism M is bulky in the same direction. The size of the interlocking mechanism M can be reduced by avoiding it, and the contact point load between the drive part D and the driven part F can be reduced, and the wear of the contact part can be effectively suppressed. Moreover, since the throttle valve V1 and the tumble valve V2 are arranged close to each other in the direction along the intake passage I (intake passage 2) in the fully opened state, the intake flow is disturbed between the valves V1 and V2. Is effectively avoided and the intake air flows smoothly to reduce the intake resistance.

Furthermore, in the present embodiment, the driving portion D and the driven portion F change with time in the valve opening angle α of the throttle valve V1 in the process of opening the tumble valve V2 in conjunction with the throttle valve V1 by mutual contact between them. The ratio P of the time change rate dβ / dt of the valve opening angle β of the tumble valve V2 with respect to the rate dα / dt, that is, (dβ / dt) / (dα / dt) is set after the initial opening of the tumble valve V2. The tumble valve V2 is formed in a shape that becomes larger when the valve is further opened. For this reason, when the drive part D starts to contact the driven part F during the opening process of the throttle valve V1 as described above, the valve opening angle change rate dβ / dt of the tumble valve V2 is relatively small. The impact at the time of contact can be reduced, and wear damage and contact sound generation at the contact portion are effectively suppressed. Meanwhile, when the drive unit D in the closing process of the throttle valve V1 is tumble valve V2 away from the driven unit F is engaged with the intake passage 2 wall (i.e. the stopper portion S T 2), the opening angle of the tumble valve V2 Since the rate of change dβ / dt is relatively small, the impact at the time of engagement with the peripheral wall of the intake passage (ie, the stopper portion ST 2) is reduced, thereby causing wear damage and contact noise of the engagement portion. Generation is effectively suppressed.

  Further, in the present embodiment, the first bearing portion Bb1 on one side of the throttle body B that pivotally supports the tumble valve V2 has a first bearing hole 11 that supports one end portion of the tumble valve shaft j2 and a step portion s therebetween. And a flange portion 14 projecting from the outer periphery of one end portion of the tumble valve shaft j2 so that one side thereof faces the step portion s. The collar C that is inserted and surrounds the outer periphery of one end portion of the tumble valve shaft j2 on the other side surface of the flange portion 14 is inserted into the mounting hole 13 so that the flange portion 14 is sandwiched between the inner end Ci and the step portion s. A stopper flange Cos that is press-fitted and engages with the outer end surface 16 of the first bearing portion Bb1 is integrally projected at the outer end Co of the collar. For this reason, after inserting the flange portion 14 at the outer periphery of one end of the tumble valve shaft j2 into the mounting hole 13, the collar C is inserted into the mounting hole 13 so that the flange portion 14 is sandwiched between the stepped portion s and the collar inner end Ci. By simply press-fitting, the axial positioning of the one end portion of the tumble valve shaft j2 with respect to the first bearing portion Bb1 can be easily and accurately performed, so that special functional parts for fixing the collar (such as bolts and nuts) are specially provided. There is no need to provide it.

  On the other hand, the second bearing portion Bb2 disposed on the opposite side of the first bearing portion Bb1 across the intake passage 2 is composed of a second bearing hole 17 formed in the throttle body B in a bag hole shape, Since the other end portion of the tumble valve shaft j2 is inserted into the second bearing hole 17, the assembly of the other end portion of the tumble valve shaft j2 to the second bearing portion Bb2 is completed simultaneously with the insertion, and the second bearing hole 17 There is no need to cover the door with a lid. As a result, the bearing holding structure for one end and the other end of the tumble valve shaft j2 is simplified as a whole, and cost savings and assembly workability are improved.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various design change is possible in the range which does not deviate from the summary.

  For example, in the above-described embodiment, the intake valve flows through the gap between the throttle valve body b1 and the intake passage 2 when the throttle valve V1 is in the closed position. However, the intake valve bypasses the throttle valve V1. A bypass intake passage with an on-off valve that circulates the gas may be attached to the throttle body B so that the intake air is circulated through the bypass intake passage when the throttle valve V1 is in the closed position.

B ... Throttle body b1 ... Throttle valve butterfly valve body b2 ... Tumble valve body D ... Drive E ... Internal combustion engine F ... ··· Following portion f ··· Virtual plane I ··· Intake passage j2 ··· Tumble valve shaft K as valve shaft ··· Notch portion L1 ··· Throttle lever L2 ··· ... Tumble lever M ... Interlocking mechanism P ... Ratio SP1, SP2 ... Valve springs ST1, ST2 ... Stopper part V1 ... Throttle valve V2 ... Tumble valve x ··· Contact start point α ··· Throttle valve opening angle β ··· Tumble valve opening angle dα / dt · · Time variation rate of throttle valve opening angle dβ / dt ·・ Time change rate of valve opening angle of tumble valve 1 ... Combustion chamber 2 ... Intake passages 5, 6 ... On as a gas passage portion, a lower intake passage portion 20c · · · outer peripheral edge

Claims (4)

A throttle body (B) having an intake passage (2) constituting a part of an intake passage (I) connected to a combustion chamber (1) of the internal combustion engine (E), and a pivotally supported on the throttle body (B) The throttle valve (V1) that can open and close the intake passage (2) and the intake passage (2) downstream of the throttle valve (V1) are rotatably supported by the throttle body (B). The tumble valves (V2), the valve springs (SP1, SP2) that urge the throttle valves (V1) and the tumble valves (V2) in the closing direction, and the urging forces of the valve springs (SP1, SP2), respectively. The stopper part (ST1, ST2) which can hold | maintain a throttle valve (V1) and a tumble valve (V2) in each closed position is resisted, and a tumble valve (V2) carries an intake air flow downstream from it. A pair of intake passage parts to divide 5,6) a intake air flow control device can be opened and closed one (6) of,
Between the throttle lever (L1) rotating integrally with the manually operated throttle valve (V1) and the tumble lever (L2) rotating integrally with the tumble valve (V2), the throttle lever (L1) In the case where an interlocking mechanism (M) capable of interlockingly rotating the tumble lever (L2) in the same rotational direction is interposed,
The interlocking mechanism (M) is integrated with the tumble lever (L2) and the drive unit (D) that rotates integrally with the throttle lever (L1). In the valve opening process in which the throttle valve (V1) rotates in the valve opening direction from its closed position, the drive unit (D) is driven in the middle of the rotation. The part (F) starts to come into contact with one side of the virtual plane (f) including the rotation axis of both valves (V1, V2), and the driven part (F) is pushed by the drive part (D) by the contact. The tumble valve (V2) rotates from the closed position to the open side ,
The tumble valve (V2) extends across the intake passage (I) and is rotatably supported by the throttle body (B), and the valve shaft (j2) is integrated with the valve shaft (j2). When the plate-shaped valve body (b2) coupled to rotate and the tumble valve (V2) is in the closed position, the intake shaft is placed on the opposite side of the valve body (b2) across the valve shaft (j2). A butterfly valve element (b1) of the throttle valve (V1) and the tumble when the throttle valve (V1) is in a fully open position in a direction along the intake passage (I). A contact start point (x) between the drive unit (D) and the driven unit (F) in the valve opening process is located between the valve shaft (j2) of the valve (V2). Intake flow control device. The drive part (D) and the driven part (F) are opened in the process of opening the tumble valve (V2) in conjunction with the throttle valve (V1) by mutual contact between them. The ratio (P) of the time change rate (dβ / dt) of the valve opening angle (β) of the tumble valve (V2) to the time change rate (dα / dt) of the angle (α) is the valve opening of the tumble valve (V2). 2. The intake flow control device according to claim 1 , wherein the intake flow control device is formed in a shape that becomes larger when the tumble valve (V <b> 2) is further opened after the initial stage. The follower (F) is molded with synthetic resin using the tumble lever (L2) fixed to the valve shaft (j2) of the tumble valve (V2) as an insert part. The intake air flow control device according to 1 or 2 . When the tumble valve (V2) is rotated to the closed position, the tumble valve (V2) has a peripheral wall of the intake passage (2) that functions as the stopper portion (ST2). The intake flow control device according to claim 1 or 2 , wherein the peripheral portion (20c) is held in a closed position by contacting the peripheral portion (20c).

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