JP2010285875A - Intake control device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a production efficiency by retaining valve seat machining at the minimum necessary level by eliminating the execution of the valve seat machining in an area of an intake path corresponding to a midway between a first and second throttle valves. <P>SOLUTION: A throttle body 10 is divided into an upstream side body half 10a and a downstream side body half 10b, in a midway in an axial direction of an intake path 11. First and second annular valve seats 12, 13 separated from each other are respectively protruded on the intake path 11 of the upstream side body half 10a and downstream side body half 10b. A first throttle valve 20 opening/closing the intake path 11 of the upstream side body half 10a is pivotally supported to the upstream side body half 10a by collaborating with a first valve seat 12. A second throttle valve 21 opening/closing the intake path 11 of the downstream side body half 10b is pivotally supported to the downstream side body half 10b by collaborating with a second valve seat 13. The upstream side body half 10a and downstream side body half 10b are fastened to each other so as to be separated from each other by a fastening member 18. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a throttle body having an intake passage connected to an intake port of an engine, a butterfly type first throttle valve for opening and closing the intake passage, and a butterfly type for opening and closing the intake passage downstream from the first throttle valve. The present invention relates to an improvement in an intake control device for an engine which is pivotally supported by the second throttle valve.

  Such an intake control device for an engine is already known, as disclosed in Japanese Patent Application Laid-Open No. H10-228707.

JP 2008-286092 A

  Conventionally, in such an intake control device for an engine, a throttle body having an intake passage is integrally formed by die casting, and after the molding, the first and second throttle valves are respectively disposed on the inner peripheral surface of the intake passage. An annular valve seat that is seated when closed is precisely machined. Therefore, at the time of die-casting, a ridge portion is formed continuously over a wide area on the inner peripheral surface of the intake passage for the above-mentioned machining allowance for cutting, and the first and second portions are cut by cutting the ridge portion. The valve seat of the second throttle valve was processed at once.

  Since the valve seats of the first and second throttle valves thus formed are continuous, useless valve seat processing is performed at the intermediate portion of the first and second throttle valves in the intake passage. This has reduced the production efficiency of the throttle body.

  The present invention has been made in view of such circumstances, and it is not necessary to perform valve seat processing in the region of the intake passage that corresponds to the intermediate portion of the first and second throttle valves. The purpose of the present invention is to provide an intake control device for an engine that can contribute to the improvement of production efficiency while keeping it to the minimum necessary level.

  In order to achieve the above object, the present invention provides a throttle body having an intake passage connected to an intake port of an engine, a butterfly-type first throttle valve that opens and closes the intake passage, and a downstream side of the first throttle valve. In an engine intake control device that is pivotally supported by a butterfly-type second throttle valve that opens and closes the intake passage, the throttle body is divided into an upstream body half and a downstream body at an intermediate portion in the axial direction of the intake passage. Annular first and second valve seats, which are divided into halves and are spaced apart from each other, are formed on the intake passages of the upstream and downstream body halves. A first throttle valve for opening and closing the intake passage of the side body half is pivotally supported on the upstream body half, and a second throttle for opening and closing the intake passage of the downstream body half in cooperation with the second valve seat Valve said downstream Rotatably supported in the body halves, the first feature that it has signed to be separated from each other by the fastening member the upstream body halves and the downstream body halves.

  According to the present invention, in addition to the first feature, an operating means capable of opening and closing the first throttle valve is connected to the first throttle valve, and the first throttle valve is connected to the second throttle valve via an interlocking mechanism. The interlock mechanism is fixed to the valve shaft of the first throttle valve and is connected to the first throttle lever having a pressing pin at the tip and the valve shaft of the second throttle valve. A second feature is that it is constituted by a driven lever that opens and closes the second throttle valve when the valve is opened beyond a predetermined opening degree.

  Furthermore, in addition to the first or the second feature, the present invention allows the driven lever to be rotatably supported on the valve shaft of the second throttle valve, and the driven lever is used as a valve of the second throttle valve. The second throttle lever fixed to the shaft is connected via an interlocking timing adjustment mechanism, and the interlocking timing adjustment mechanism is configured such that when the first and second throttle valves are fully closed, the distance between the pressing pin and the driven lever is opposed to each other. It is a third feature that it is configured to be able to adjust.

  Furthermore, the present invention is characterized in that, in addition to any of the first to third features, an intake pipe joined to the engine is integrally formed on the downstream body half.

  Furthermore, in addition to the fourth feature, a fifth feature is that a fuel injection valve for injecting fuel toward the intake port of the engine is attached to the intake pipe.

  According to the first aspect of the present invention, the divided upstream and downstream body halves have an annularly raised first valve seat cooperating with the first throttle valve and a second throttle. Since the annularly raised second valve seats cooperating with the valve are molded apart from each other, the intermediate region of the first and second valve seats not involved in closing the first and second throttle valves is As with the outside of both valve seats, it can be a general surface that is one step backward from both valve seats. Therefore, when finishing the first and second valve seats after molding each body half, the first and second valves are not involved in closing the first and second throttle valves in the intake passage. The intermediate region of the seat can be a general surface that is one step backward from both valve seats, as is the case with the outside of both valve seats. 2 It can be set to the minimum necessary for closing the throttle valve, and it can reduce the production area of the first and second valve seats, reduce the processing time and prolong the life of the processing tool, as well as save materials. Efficiency can be improved and costs can be reduced.

  Further, since the upstream and downstream body halves are connected to each other by bolts, the first and second throttle valves can be easily maintained by disassembling them.

  According to the second feature of the present invention, the interlock start timing of the first and second throttle valves can be easily and accurately set simply by the contact timing of the pressing pin with the driven lever, and the upstream and downstream When the side body half is disassembled, the pressing pin and the driven lever are simply separated from each other, and no special disassembly work of the interlocking mechanism is required, thereby further improving the maintainability.

  According to the third feature of the present invention, when the first and second throttle valves 20 and 21 are fully closed by the interlocking timing adjustment mechanism, both the throttle valves are adjusted by adjusting the facing distance between the pressing pin and the driven lever. It is possible to easily adjust the interlock start time.

  According to the fourth feature of the present invention, the integration of the downstream body half and the intake pipe can reduce the number of parts and the number of assembly steps of the entire intake control device, thereby contributing to further cost reduction. . Further, since the length of the intake pipe can be shortened without interference from adjacent members, the length of the entire intake pipe including the throttle body can be shortened.

1 is a side view of an intake control device for a motorcycle engine according to a first embodiment of the present invention; The longitudinal side view of the same intake control device. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. The perspective view of the interlocking mechanism in FIG. FIG. 4 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention. The vertical side view of the 2nd Example.

  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, the description starts with the description of the first embodiment of the present invention shown in FIGS. 1 to 3, a joint flange 3 a of an intake short pipe 3 connected to an intake port 2 of the cylinder head 1 of the engine E is joined by a bolt 4. Together with this, a rubber connecting pipe 5 constituting an elbow-shaped intake pipe 6 is connected, and a throttle body 10 is connected to the connecting pipe 5. The throttle body 10 has an intake passage 11 that communicates with the intake port 2 via the intake pipe 6. A fuel injection valve 7 capable of injecting fuel toward the intake port 2 is attached to the intake short pipe 3.

  The throttle body 10 is divided into an upstream body half 10a and a downstream body half 10b at an intermediate portion in the axial direction of the intake passage 11, and the intake passage 11 of these upstream and downstream body halves 10a, 10b , The annular first and second valve seats 12 and 13 spaced apart from each other are raised. These upstream and downstream body halves 10a and 10b are individually formed by die casting, and the raised heights of the first and second valve seats 12 and 13 formed at the time of casting are finished. A teenager is expected. That is, after the individual casting of the upstream and downstream body halves 10a and 10b, the first and second valve seats 12 and 13 are each finished by cutting or the like. The closing accuracy of the throttle valves 20 and 21 can be increased.

  Further, when casting the upstream and downstream body halves 10a and 10b, first and second flanges 14 and 15 are respectively formed at the opposed end portions, and an annular end surface is formed on one end face of these flanges 14 and 15 respectively. A seal groove 16 is formed. After the casting, the first and second flanges 14 and 15 are fastened to each other by a plurality of bolts 18 with the O-ring 17 attached to the seal groove 16, and thus the upstream and downstream body halves 10a and 10b. Are integrally connected to each other.

  The upstream body half 10a has a valve shaft 20a (hereinafter referred to as a first valve shaft 20a) of a first throttle valve 20 that opens and closes the intake passage 11 of the upstream body half 10a in cooperation with the first valve seat 12. ) Is rotatably supported, and the downstream body half 10b cooperates with the second valve seat 13 to open and close the intake passage 11 of the downstream body half 10b. (Hereinafter referred to as the second valve shaft 21a) is rotatably supported. A bearing member 22 and a seal member 23 are attached to the bearing portions of the upstream and downstream body halves 10a and 10b with respect to the first and second valve shafts 20a and 21a as necessary.

  As shown in FIGS. 1-4, the 1st and 2nd valve shafts 20a and 21a are arrange | positioned in parallel. A drum-type first throttle lever 25 is fixed to one end of the first valve shaft 20a. The first return spring biases the first throttle lever 25 in the closing direction of the first throttle valve 20. 26 is connected. An operation wire 27 extending from a throttle grip (not shown) of the motorcycle is connected to the first throttle lever 25, and the first throttle valve 20 can be opened by pulling the operation wire 27. On the outer surface of the first throttle lever 25, a pressing pin 28 with a roller 28a is projected.

  On the other hand, a second throttle lever 29 is fixed to one end of the second valve shaft 21a. Further, a driven lever 31 adjacent to the second throttle lever 29 is rotatably supported at one end of the second valve shaft 21a. The driven lever 31 and the second throttle lever 29 are connected via an interlocking timing adjusting mechanism 34. Connected to each other. Thus, the driven lever 31 and the second throttle lever 29 can normally rotate together to open and close the second throttle valve 21.

  The back surface of the driven lever 31, that is, the surface opposite to the opening direction of the second throttle valve 21, is formed on the cam surface 31a. When the first and second throttle valves 20, 21 are fully closed, the cam surface 31a In addition, the pressing pins 28 are opposed to each other with a predetermined interval S therebetween. In the above, the first throttle lever 25, the pressing pin 28, the driven lever 31, and the second throttle lever 29 constitute an interlocking mechanism 33 that interlocks and connects the first and second valve shafts 20a and 21a.

  The interlocking timing adjusting mechanism 34 is formed on the driven lever 31 so as to be bent on one side thereof, and on the one side surface of the first protruding piece 36 formed on the second throttle lever 29. Between the first and second projecting pieces 36 and 37, the second projecting piece 37 formed on the second throttle lever 29 and opposed to the other side of the first projecting piece 36. A connecting spring 39 that is contracted and biases the first projecting piece 36 toward the third projecting piece 38, and is screwed to the third projecting piece 38, and cooperates with the connecting spring 39 to form the first projecting piece 36. It is comprised with the adjustment bolt 40 which can adjust the relative position of the 2 protrusion piece 37, and the load of the connection spring 39 is set larger than the set load of the said 2nd return spring 30. FIG.

  Thus, when the adjusting bolt 40 is advanced and retracted with respect to the first projecting piece 36 in the fully closed state of the first and second throttle valves 20 and 21, the first projecting piece 36, that is, the driven lever 31 is moved to the second throttle. The rotation of the valve 21 is adjusted, whereby the facing distance between the cam surface 31a of the driven lever 31 and the pressing pin 28 of the first throttle lever 25 can be adjusted to a predetermined distance. Therefore, when the first throttle lever 25 is opened to a predetermined opening, the pressing pin 28 comes into contact with the cam surface 31a of the driven lever 31 and the operation of the interlocking mechanism 33 is started. After the adjustment of the interlocking timing adjusting mechanism 34, the first to third projecting pieces 36 to 38 are connected via the connecting spring 39 and the adjusting bolt 40, whereby the driven lever 31 is fixed to the second valve shaft 21a. 2 When the pressing pin 28 presses the cam surface 31a, the driven lever 31 and the second throttle lever 29 are rotated together, and the second valve shaft 21a, that is, the second throttle valve 21 is moved. Will open. At that time, the opening characteristic of the second throttle valve 21 with respect to the first throttle valve 20 can be set by the shape of the cam surface 31a.

  A bypass joint 42 that opens to the intake passage 11 upstream of the second throttle valve 21 is attached to the downstream body half 10 b, and the bypass joint 42 is connected to the intake pipe in the vicinity of the fuel injection portion of the fuel injection valve 7. A bypass (not shown) for supplying air into 6 is connected. Thus, when the engine in which the second throttle valve 21 is fully closed is idling or operating at an extremely low speed, intake air measured by the first throttle valve 20 is supplied to the engine E through the bypass. Yes.

  Next, the operation of this embodiment will be described.

  The upstream body half 10a and the downstream body half 10b, which are divided from each other and constitute the throttle body 10, are individually cast, and the intake passage 11 of the upstream body half 10a has a first throttle valve 20 and An annularly raised first valve seat 12 cooperates, and an annularly raised second valve seat 13 cooperates with the second throttle valve 21 in the intake passage 11 of the downstream body half 10b. In this case, the valve seats 12 and 13 are spaced apart from each other. Since the first and second valve seats 12 and 13 are finished after casting, the first and second valve seats 12 and 13 are not involved in closing the first and second throttle valves 20 and 21 in the intake passage 11. The intermediate region of the valve seats 12 and 13 can be a general surface that is retracted by one step from the valve seats 12 and 13, similarly to the outside of the valve seats 12 and 13. As a result, the axial widths of the first and second valve seats 12 and 13 can be set to the minimum necessary for closing the first and second throttle valves 20 and 21, and the first and second The finishing area of the second valve seats 12 and 13 can be reduced, thereby shortening the machining time and extending the life of the machining tool, thereby improving the production efficiency and reducing the cost.

  Further, since the upstream and downstream body halves 10a and 10b are detachably coupled to each other by the bolt 18, the first and second throttle valves 20 and 21 are easily maintained by disassembling them. be able to. The first and second valve seats 12 and 13 can be finished before and after the upstream and downstream body halves 10a and 10b are joined.

  In addition, the interlock mechanism 33 between the first and second throttle valves 20 and 21 is fixed to the first valve shaft 20a and connected to the first throttle lever 25 having the pressing pin 28 at the tip and the second valve shaft 21a. When the first throttle valve 20 is opened to a predetermined opening or more, the first and second throttle valves are configured to be driven by the pressing pin 28 to open the second throttle valve 21. The interlocking start timing of the valves 20 and 21 can be set easily and accurately simply by the contact timing of the pressing pin 28 with respect to the driven lever 31, and at the time of disassembly of the upstream and downstream body halves 10a and 10b, Since the pin 28 and the driven lever 31 are simply separated from each other, a special disassembly operation of the interlocking mechanism 33 is unnecessary, and the maintainability is further improved.

  Further, the driven lever 31 is connected to a second throttle lever 29 fixed to the second valve shaft 21a via an interlocking timing adjustment mechanism 34, and the interlocking timing adjustment mechanism 34 allows the first and second throttle valves 20 to be driven. , 21 is adjusted so that the opposing distance S between the pressing pin 28 and the driven lever 31 is adjusted, so that the interlock start timing of the two throttle valves 20, 21 can be adjusted.

  Next, a second embodiment of the present invention shown in FIGS. 5 and 6 will be described.

  In the second embodiment, the downstream body half 10b and the elbow-shaped intake pipe 6 to which the fuel injection valve 7 is attached are integrally formed by casting. Accordingly, the intake pipe 6 is provided with a fuel injection valve 7 at its downstream end, and a joining flange 3a joined to the cylinder head 1 at its downstream end. Since the other configuration is the same as that of the previous embodiment, portions corresponding to those of the previous embodiment in FIG. 5 and FIG.

  According to the second embodiment, the integration of the downstream body half 10b and the intake pipe 6 can reduce the number of parts and the number of assembling steps of the entire intake control device, which can contribute to further reduction in cost. Further, the integration of the downstream body half 10b and the intake pipe 6 eliminates the need for the connection pipe 5 as in the previous embodiment, so that the length of the intake pipe 6 is at least equivalent to the length of the connection pipe 5. The length of the intake pipe 6 can be shortened without being interfered by adjacent members, whereby the length of the entire intake pipe including the throttle body 10 can be shortened.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the fuel injection valve 7 can be mounted on the downstream body half 10b.

E ... Engine 2 ... Intake port 6 ... Intake pipe 7 ... Fuel injection valve 10 ... Throttle body 10a ... Upstream body half 10b ··· Downstream side body half 11 ··· intake passage 12 ··· first valve seat 13 ··· second valve seat 18 ··· fastening member 20 ··· first throttle valve 21 ··· ... Second throttle valve 25 ... First throttle lever 27 ... Operating means (operating wire)
28 ... Push pin 29 ... Second throttle lever 31 ... Drive lever 33 ... Interlock mechanism 34 ... Interlock timing adjustment mechanism

Claims (5)

A throttle body (10) having an intake passage (11) connected to an intake port (2) of an engine is provided with a butterfly-type first throttle valve (20) for opening and closing the intake passage (11), and the first throttle valve ( 20) In an intake control device for an engine, which is pivotally supported by a butterfly-type second throttle valve (21) that opens and closes the intake passage (11) on the downstream side of the engine.
The throttle body (10) is divided into an upstream body half (10a) and a downstream body half (10b) at an axially intermediate portion of the intake passage (11), and these upstream and downstream body halves are divided. An annular first and second valve seats (12, 13) that are spaced apart from each other are formed on the intake passage (11) of (10a, 10b) so as to be raised, and in cooperation with the first valve seat (12), The first throttle valve (20) that opens and closes the intake passage (11) of the side body half (10a) is pivotally supported by the upstream body half (10a) and cooperates with the second valve seat (13). A second throttle valve (21) for opening and closing the intake passage (11) of the downstream body half (10b) is pivotally supported by the downstream body half (10b), and the upstream body half (10a) and Downstream body half (10b) can be separated from each other by fastening member (18) Characterized in that it entered into, intake control device for an engine. The intake control apparatus for an engine according to claim 1,
The first throttle valve (20) is connected to an operating means (27) capable of opening and closing the first throttle valve (20), and the first throttle valve (20) is connected to the second throttle valve (21) with an interlocking mechanism (33). The interlock mechanism (33) is fixed to the valve shaft (20a) of the first throttle valve (20), and has a first throttle lever (25) having a pressing pin (28) at the tip, The second throttle valve (21) is connected to the valve shaft (21a), and when the first throttle valve (20) opens more than a predetermined opening degree, the second pin is abutted and rotated by the pressing pin (28). 2. An engine intake control device comprising a driven lever (31) for opening a throttle valve (21). The intake control apparatus for an engine according to claim 1 or 2,
The driven lever (31) is rotatably supported on the valve shaft (21a) of the second throttle valve (21), and the driven lever (31) is mounted on the valve shaft (21) of the second throttle valve (21). 21a) is connected to a second throttle lever (29) fixedly attached via an interlocking timing adjustment mechanism (34), and the interlocking timing adjustment mechanism (34) is connected to the first and second throttle valves (20, 21). The engine intake control device is configured to be able to adjust the facing distance (S) between the pressing pin (28) and the driven lever (31) when fully closed. The intake control apparatus for an engine according to any one of claims 1 to 3,
An intake control device for an engine, wherein an intake pipe (6) joined to the engine (E) is integrally formed with the downstream body half (10b). The intake control apparatus for an engine according to claim 4,
An intake control device for an engine, wherein a fuel injection valve (7) for injecting fuel toward the intake port (2) of the engine (E) is attached to the intake pipe (6).

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