JPH0587229U - Variable intake system for multi-cylinder engine - Google Patents

Abstract

(57) [Summary] [Object] To provide a variable intake device that facilitates adjustment of the initial position of the movable member of each cylinder and prevents variation in the movement of the movable member between the cylinders. A variable intake device in a multi-cylinder engine in which the intake characteristic of each intake pipe 41 changes. Support part 4 of each intake pipe 41
1a includes a drive shaft 50 that is rotatably supported, and a swing arm 52 that is provided in each intake pipe and swings by the rotation of the drive shaft to drive the funnel. The connecting portion with the shaft 50 is a tapered fitting portion where the tapered portions 52a and 510b are fitted by tightening the fastening nuts N1 and N2, and the spring 57 that biases each swing arm 52 toward the minimum pipe length position is provided. It is provided. By tightening the fastening nuts N1 and N2, the swing center of each swing arm is automatically aligned with the axis of the drive shaft while each funnel is held at the initial position on the minimum pipe length position side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a variable intake system in a multi-cylinder engine for an automobile, which can change the intake efficiency by changing the length of each intake pipe according to the engine speed.

[0002]

[Prior Art]

 Conventionally, as a variable intake device in such a multi-cylinder engine, for example, an intake pipe tip portion (funnel) detachably provided in the intake pipe main body of each cylinder and each funnel that is rocked by rotation of a motor are used. It is equipped with a link mechanism that displaces between the position connected to the intake pipe body (the position where the intake pipe becomes longer) and the position separated from this body (the position where the intake pipe becomes shorter). It is known that it can be switched to two stages (Japanese Utility Model Publication No. 3-87825).

In addition, as a variable intake device in a multi-cylinder engine, a funnel is slidably fitted to each intake pipe body, and each funnel is connected by a link mechanism that is driven in association with rotation of a motor. It is known that the length of each intake pipe is changed by displacing the intake pipe main body in the axial direction.

[0004]

[Problems to be solved by the device]

 Generally, in such a variable intake system in a conventional multi-cylinder engine, the funnels (movable tubes) of the cylinders must be driven in synchronization so that the movement of the funnels of the cylinders does not vary. It is necessary to adjust the funnel of each cylinder so that it takes the same initial position (minimum or maximum pipe length position) when the variable intake device is installed in the engine.

It is desired that the initial position of the funnel of each cylinder can be easily adjusted and the movement of the funnel does not vary among the cylinders.

The present invention has been made in view of such conventional circumstances, and facilitates adjustment of the initial position of the movable member of each cylinder, and the movement of the movable member varies among the cylinders. It is an object of the present invention to provide a variable intake system for a multi-cylinder engine that prevents the occurrence of such a problem.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention has a variable intake mechanism for changing the intake efficiency in the intake pipe of each cylinder, and the drive force of the actuator is transmitted through the transmission mechanism so that each variable In a variable intake system in a multi-cylinder engine configured so that the movable member of the intake mechanism is driven to change the intake characteristic of each intake pipe, the entire multi-cylinder is driven by the shaft to which the driving force is transmitted through the transmission mechanism. Drive shafts, which are integrated so as to extend over the entire length of the intake pipes and are rotatably supported by the support portions of the intake pipes, and the intake pipes, which are provided on the intake pipes and which are swung by the rotation of the drive shafts. A swinging member that drives the movable member, and a connecting portion between each swinging member and the drive shaft is a taper fitting portion in which the taper portions are fitted by tightening a fastening nut. Move the member to the minimum or maximum movable position side In which the biasing member to energize are provided (claim 1).

[0008] Preferably, two rocking members are arranged on both sides of each intake pipe of the intake pipe of each cylinder, and the two rocking members of each intake pipe are screws opposite to each other. It is fastened by the fastening nut (claim 2).

[0009] Preferably, the drive shaft is supported by a support portion of each of the intake pipes via a bearing (claim 3).

[0010]

[Action]

 In the variable intake device according to claim 1, since the swinging member of each suction pipe is biased by the biasing member to be held at the minimum or maximum movable position side before the fastening nut is tightened, each suction pipe is held. If the movable nuts are automatically adjusted to the initial position and the fastening nuts are tightened in this state, the rocking members and the drive shaft will not be able to contact each other at their tapered portions while the movable members are held at the initial positions. Since they are fitted and connected, the swing center of each swing member is automatically aligned with the axis of the drive shaft.

In the variable intake system according to claim 2, since the two rocking members of each intake pipe are fastened by the fastening nuts which are mutually opposite threads, the two fastening nuts of each intake pipe are in the same direction. The two tightening nuts become double nuts. Further, in the variable intake system according to the third aspect, since the drive shaft is supported by the support portion of each intake pipe via the bearing, the movable pipe of each cylinder is smoothly driven.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

In the description of each embodiment, the same parts are designated by the same reference numerals, and the duplicated description will be omitted.

FIG. 1 is a sectional view showing a V-type 8-cylinder engine E in which a variable intake system 1 according to a first embodiment of the present invention is used.

As shown in FIGS. 2 and 5, between the banks 2 and 3 of the V-type 8-cylinder engine E, the same number (4) of intake pipes 41 to 44, 45 to 45 as the cylinders of the banks 2 and 3 are provided. An intake system 4 is arranged in which two intake pipe rows 4a and 4b in which 48 are arranged in a row are opposed to each other. Each of the intake pipes 41 to 48 is connected to a main body 41A to 48A and an inlet side pipe which is fastened to the main body by mounting holes 41C to 48C (see FIGS. 1 and 5) with bolts (not shown). 41B to 48B.

As shown in FIGS. 2, 3 and 6, the variable intake device 1 includes a variable pipe length mechanism (variable intake mechanism) 5, which is provided in each of the intake pipe rows 4a and 4b for changing the intake efficiency. 6 and the two actuators 7 and 70 arranged between the intake pipe rows 4a and 4b, and the rotation of the output shafts (hereinafter referred to as motor output shafts) 7a and 70a of the actuators 7 and 70, respectively. Transmission mechanisms 8 and 80 for transmitting the pipe length varying mechanisms 5 and 6 by transmitting to the drive shafts 50 and 60 of 5 and 6, respectively.

Each of the actuators 7 and 70 includes a motor 71 and a casing 72 fixed to the motor 7, as shown in FIGS. 2, 3, and 6. The casing 72 is fixed to the mounting portion 9a integral with the cylinder block 9 with bolts 9b.

As shown in FIGS. 2, 3 and 6, each of the transmission mechanisms 8 and 80 includes an output gear 811 integrated with the motor output shafts 7 a and 70 a, and a reduction gear 812 meshing with the gear 811. The output shafts 813a and 813b are integrated with the reduction gear 812, and the link mechanisms 820 and 830 that transmit the rotation of the output shafts 813a and 813b to the drive shafts 50 and 60. As shown in FIG. 6, each output shaft 813a, 813b is rotatably supported by a casing 72 by a bearing 72a.

As shown in FIGS. 3 and 6, the link mechanism 820 is integrally formed with the output shaft 813a, and has an output shaft side lever 821 that rotates together with the output shaft 813a and one end of the output shaft side lever 821. A connecting rod 823 rotatably connected to the free end of the lever 821 with a bolt 822, one end rotatably connected to the other end of the connecting rod 823 with a bolt 824, and the other end to the drive shaft 50. It is composed of a fixed drive shaft side lever 825.

On the other hand, as shown in FIGS. 3 and 6, the link mechanism 830 is integrally formed with the output shaft 813b and has an output shaft side lever 831 which rotates together with the output shaft 813b and one end of which is output. A connecting rod 833 rotatably connected to the free end of the shaft side lever 831 by a bolt 832, one end rotatably connected to the other end of the connecting rod 833 by a bolt 834, and the other end of the drive shaft 60. And a drive shaft side lever 835 fixed to.

The other ends of the drive shaft side levers 825 and 835 are joint parts 825a and 835a (see FIGS. 5 and 6).

The transmission mechanisms 8 and 80 having such a configuration output the motor output so that the variable tube length mechanisms 5 and 6 are driven in the same direction and in the same amount in association with the rotation of the motor output shafts 7a and 70a. The rotation of the shafts 7a and 70a is transmitted to the drive shafts 50 and 60. As shown in FIGS. 1, 3 and 5, each of the pipe length varying mechanisms 5, 6 has a minimum pipe length position (position shown in FIG. 3) at the inner circumference of the inlet side end of each intake pipe 41-44, 45-48. , The minimum movable position) and the maximum pipe length position (the maximum movable position at the position shown in FIG. 1), and the funnels (movable members) 51 and 61 slidably fitted in the axial direction, and the intake pipes 41 to 44, respectively. The drive shafts 50 and 60 rotatably supported by the support portions 41a to 44a and 45a to 48a formed on the inlet side pipe portions 41B to 44B and 45B to 48B of the 45 to 48, and the drive shafts 50 and 60, respectively. Of the intake pipes 41 to 44, 45 to 48, and drives the funnels 51 and 61 of the intake pipes 41 to 44, 45 to 48.

The drive shafts 50 and 60 are integrated so as to extend over the entire intake pipe rows 4a and 4b (see FIG. 5). That is, the drive shaft 50 has four drive shaft portions 510, 520, 530, 540 supported by the respective support portions 41 a, 42 a, 43 a, 44 a, and the drive shaft portions 510 and 520 are joints 53. Thus, the drive shaft portions 520 and 530 are integrally connected by the joint portion 825 a of the drive shaft side lever 825 of the link mechanism 820, and the drive shaft portions 530 and 540 are integrally connected by the joint 54. Then, in this connected state, the shaft centers of the drive shaft portions 510 to 540 are aligned.

On the other hand, the drive shaft 60 has four drive shaft portions 610, 620, 630, 640 supported by the respective support portions 45a, 46a, 47a, 48a, and the drive shaft portions 610 and 620 are The drive shaft portions 620 and 630 are integrally connected by the joint 63 by the joint portion 835a of the drive shaft side lever 835 of the link mechanism 830, and the drive shaft portions 630 and 640 are integrally connected by the joint 64. Then, in this connected state, the axes of the drive shaft portions 610 to 640 are aligned.

The joints 825a and 835a of the drive shaft side levers 825 and 835 of the link mechanisms 820 and 830 are located substantially at the center of the drive shafts 50 and 60 (see FIGS. 5 and 5). 6), whereby the rotation of each motor output shaft 7a, 70a is input to the substantially central portion of each drive shaft 50, 60 via each link mechanism 820, 830.

As shown in FIGS. 1 and 5, two swing arms 52 and 62 are arranged in each of the intake pipes 41 to 48 on both sides of each intake pipe. The drive shaft portion 510 of the drive shaft 50 includes large-diameter shaft portions 510a and 510a rotatably supported in the support holes 41b and 41b of the support portion 41a of the intake pipe 41 via bearings 55 and 55, respectively. Tapered portions 510b and 510b on the outside of each large diameter shaft portion 510a, and a right screw 510c and a left screw 510d on the outer side of each tapered portion 510b are formed. On the other hand, as shown in FIGS. 1 and 3, the swing arms 52 arranged on both sides of the suction pipe 41 are fixed to the taper portions 52a fitted to the respective taper portions 510b and the funnel 51 on both sides. A long hole 52b into which the engagement pin 56 is slidably fitted, an opening 52c for inserting the engagement pin 56 into the long hole 52b, and the engagement pin 56 does not come off from the long hole 52b during swinging. The stopper portion 52d is formed. Further, between the both side walls of the support portion 41a and each swing arm 52, each swing arm 52 with the fastening nuts N1 and N2 loosened is provided with the minimum pipe length position (initial pipe length position) shown in FIG. A spring (biasing member) 57 for biasing and holding is interposed.

The support portions 42 a to 48 a of the intake pipes 42 to 48 also have the same structure as the support portion 41 a of the intake pipe 41. Further, each of the drive shaft portions 520 to 540 and 610 to 640 also has a structure similar to that of the drive shaft portion 510. Further, the swing arm 62 also has a structure similar to that of the swing arm 52, that is, a taper portion (not shown), an elongated hole 62b, an opening 62c, and a stopper portion 62d.

In this way, the connecting portion between each swing arm 52 and each drive shaft portion 510 to 540 is connected to the taper fitting portions 52a and 510b by tightening the tightening nuts N1 and N2. There is. Similarly, the connecting portion between each swing arm 62 and each drive shaft portion 610 to 640 is a taper fitting portion into which taper portions (not shown) are fitted by tightening the fastening nuts N1 and N2.

Next, a procedure for assembling the pipe length varying mechanisms 5 and 6 to the intake pipe rows 4a and 4b will be described.

First, before the inlet side pipe portions 41B to 44B of the intake pipes 41 to 44 are fastened to the main body portions 41A to 44A at the mounting holes 41C to 44C with bolts, the inlet side pipe portions 41B to As shown in FIGS. 5 and 6, the pipe length varying mechanism 5 is assembled to 44B, and after this assembly, the inlet side pipe parts 41B to 44B are fastened to the main body parts 41A to 44A with bolts. Similarly, before the inlet side pipe portions 45B to 45B of the intake pipes 45 to 48 are fastened to the main body portions 45A to 48B with bolts, the pipe lengths of the inlet side pipe portions 45B to 48B are variable as shown in FIG. The mechanism 6 is assembled, and after this assembly, the inlet side tube portions 45B to 48B are fastened to the main body portions 45A to 48A with bolts.

Specifically, first, as shown in FIGS. 1 and 5, one drive shaft portion 510 is inserted into the support hole 41b of the support portion 41a of the inlet side pipe portion 41B of the suction pipe 41, and the left and right Of the funnel 51 in which the tapered portions 52a of the swing arm 52 are fitted in the tapered portions 510b of the drive shaft portion 510 and the long holes 52b of the swing arms 52 are fitted in the inlet side pipe portion 41B. The engagement pin 56 is engaged, and the fastening nuts N1 and N2 are loosely fastened to the right screw 510c and the left screw 510d of the drive shaft 510, respectively. In this way, the drive shaft portion 510, the left and right swing arms 52, and the funnel 51 are attached to the inlet side pipe portion 41B of the intake pipe 41.

As for the other intake pipes 42 to 44, similarly to the intake pipe 41, the drive shaft parts 520 to 540, the left and right swing arms 52, and the funnels 51 are attached to the respective inlet side pipe parts 42B to 44B.

After such assembly, the drive shafts 510 and 520 are connected by the joint 53, the drive shafts 520 and 530 are connected by the joint 825a of the drive shaft side lever 825 of the link mechanism 820, and , The drive shafts 530 and 540 are connected by a joint 54. As a result, the drive shaft 50 is integrated.

The inlet side pipe portions 41B to 44B connected through the drive shaft 50 integrated in this way are fastened to the main body portions 41A to 44A at the mounting holes 41C to 44C with bolts. ..

After this fastening, all the left and right fastening nuts N1 and N2 of the intake pipes 41 to 44 are loosened. As a result, the left and right swing arms 52 of the intake pipes 41 to 44 are urged and held at the minimum pipe length position (initial position) shown in FIG. The funnel 51 is automatically adjusted to the initial position shown in FIG.

Next, the fastening nuts N1 and N2 of the drive shafts 510 to 540 are tightened in the same direction on the right screw 510c and the left screw 510d, respectively. As a result, with the swing arm 52 of each intake pipe 41 to 44 held at the minimum pipe length position, the taper portion 52a of each swing arm 52 and the taper portion 510b of each drive shaft portion 510 to 540 (drive shaft portion Each of the swing arms 52 and each of the drive shaft portions 510 to 540 are integrally connected by a taper fitting portion into which the taper portions of 520 to 540 are omitted. In this connected state, since the respective swing arms 52 and the respective drive shaft portions 510 to 540 are coupled by connecting the tapered portions 52a and 510b thereof, the swing center of each swing arm 52 is different from each other. The axes of the drive shafts 510 to 540 are automatically aligned.

In this way, the assembling of the pipe length varying mechanism 5 to the intake pipes 41 to 44 is completed.

Further, with respect to the intake pipes 45 to 48, the pipe length varying mechanism 6 is assembled in the same procedure as in the case of the intake pipes 41 to 44 described above.

Next, the operation of the first embodiment having the above configuration will be described.

Now, when the engine speed decreases when the funnels 51, 61 of the intake pipes 41-44, 45-48 are at the minimum pipe length position shown in FIG. 3, for example, the motors of the actuators 7, 70 are reduced. The output shafts 7a and 70a rotate in mutually opposite directions. For example, the motor output shaft 7a rotates normally and the motor output shaft 70a rotates reversely. The respective rotations are transmitted to the output shafts 813a and 813b via the output gears 811 and the reduction gears 812 in the actuators 7 and 70, respectively, and the output shaft 813a rotates counterclockwise in FIG. Rotate in each direction.

When the output shaft 813a rotates counterclockwise in FIG. 3, the output shaft side lever 821 of the link mechanism 820 rotates together with the output shaft 813a in the counterclockwise direction from the position shown in FIG. Is transmitted to the drive shaft side lever 825 via the connecting rod 823, and the lever 825 rotates clockwise from the position of FIG. This rotation causes the drive shaft 50 to rotate clockwise from the position shown in FIG. 3, so that the left and right swing arms 52 of the intake pipes 41 to 44 swing clockwise from the position shown in FIG. The pin 56 is pushed upward from the position of FIG. 3, whereby the funnel 51 of each intake pipe 41 to 44 is displaced upward from the minimum pipe length position (initial position) of FIG. 3 and the pipe length of each intake pipe 41 to 44 is increased. It will be longer (see Figure 4).

On the other hand, when the output shaft 813b rotates clockwise in FIG. 3, the output shaft side lever 831 of the link mechanism 830 rotates together with the output shaft 813b in the clockwise direction from the position shown in FIG. The motion is transmitted to the drive shaft side lever 835 through the connecting rod 833, and the lever 835 rotates counterclockwise from the position of FIG. This rotation causes the drive shaft 60 to rotate counterclockwise in FIG. 3, so that the left and right swing arms 62 of the intake pipes 45 to 48 swing counterclockwise from the position in FIG. The dowel pin 56 is pushed upward from the position in FIG. 3, whereby the funnel 61 of each intake pipe 45 to 48 is displaced upward from the minimum pipe length position in FIG. Pipe length increases (see Figure 4).

Contrary to the above, when the funnels 51 and 61 of the intake pipes 41 to 44, 45 to 48 are at the maximum pipe length position shown in FIG. 4, for example, when the engine speed increases, the motor output shaft is increased. 7a rotates in the reverse direction, and the motor output shaft 70a rotates in the normal direction. These rotations are transmitted to the output shafts 813a and 813b via the output gears 811 and the reduction gears 812 in the actuators 7 and 70, respectively, and the output shaft 813a is clockwise and the output shaft 813b is the same. Rotate counterclockwise respectively.

When the output shaft 813a rotates clockwise in FIG. 4, the output shaft side lever 821 of the link mechanism 820 rotates clockwise from the position in FIG. 4, and this rotation causes the connecting rod 823 to move. It is transmitted to the drive shaft side lever 825 via this, and this lever 825 rotates counterclockwise from the position of FIG. This rotation causes the drive shaft 50 to rotate counterclockwise, so that the left and right swing arms 52 of the intake pipes 41 to 44 swing counterclockwise from the position shown in FIG. Pushing downward from the position of FIG. 4, the funnel 51 of each suction pipe 41-44 is displaced downward from the maximum pipe length position of FIG. 4, and the pipe length of each suction pipe 41-44 is shortened (see FIG. 3). ..

On the other hand, when the output shaft 813b rotates counterclockwise in FIG. 4, the output shaft side lever 831 of the link mechanism 830 rotates counterclockwise from the position in FIG. 4, and this rotation is connected. It is transmitted to the drive shaft side lever 835 via the rod 833, and the lever 835 rotates clockwise from the position in FIG. This rotation causes the drive shaft 60 to rotate in the time direction in the figure, so that the left and right swing arms 61 of the intake pipes 45 to 48 swing in the time direction in FIG. Is pushed downward from the position shown in the same figure, whereby the funnel 51 of each cylinder is displaced downward from the maximum pipe length position in FIG. 4 by the same amount as the funnel 51, and the pipe length of each intake pipe 45 to 48 is shortened (see FIG. 3). See).

According to the first embodiment described above, the inlet-side tube portions 41B to 44B and 45B to 48B connected via the integrated drive shafts 50 and 60 are connected to the main body portions 41A to 44A and 45A, respectively. Up to 45A at the mounting holes 41C to 44C and 45C to 48C with bolts, and then loosen all the left and right fastening nuts N1 and N2 of the intake pipes 41 to 44, 45 to 48, respectively. Since the left and right swing arms 52, 62 of ~ 44, 45-48 are urged and held at the minimum pipe length position (initial position) shown in FIG. 3 by the urging force of the spring 57, the intake pipes 41-44, 45-45. The 48 funnels 51, 61 are automatically adjusted to the initial position shown in FIG. Therefore, it becomes easy to adjust the funnels 51, 61 of the intake pipes (cylinders) 41-44, 45-48 to the initial positions, and the funnels are connected between the intake pipes (cylinders) 41-44, 45-48. It is possible to prevent variations in the movements of 51 and 61.

The drive shafts 510 to 540 and 610 to 640 are provided with right and left screws 510c and 510d, which are reverse screws to which the left and right nuts N1 and N2 are fastened (as described above, the drive shafts 520 to 520). 540 and 610 to 640 have the same structure as the drive shaft portion 510 shown in FIG. 1, and the left and right nuts N1 and N2 of each drive shaft portion are respectively provided with the right screw 510c and By tightening the left screw 510d in the same direction, the swinging arms 52, 62 of the intake pipes 41-44, 45-48 are held at the minimum pipe length position, and the taper portion of each swinging arm 52, 62 is held. 52a (as described above, the swing arm 62 has the same structure as the swing arm 52 shown in FIG. 1) and the taper portion 510b (drive shaft portion) of each drive shaft 510-540, 610-640. 520-540, 61 The taper portions 0 to 640 are not shown in the drawing), and the swinging arms 52 and 62 and the drive shaft portions 510 to 540 and 610 to 640 are integrally formed by a taper fitting portion. Therefore, the center of swing of each swing arm 52, 62 is automatically aligned with the axis of each drive shaft 510-540, 610-640. Therefore, the work of assembling the variable pipe length mechanisms 5, 6 to each intake pipe can be easily performed.

Further, according to the first embodiment, the large-diameter shaft portion 510a of each of the drive shaft portions 510 to 540 and 610 to 640 has the support portions 41a to 44a and 45a of the intake pipes 41 to 44, 45 to 48. 48a of support holes 41b, 41b (as described above, the support portions 42a-44a, 45a-48a have the same structure as the support portion 41a shown in FIG. 1) through the bearings 55, respectively. Since it is rotatably supported, the funnels 51 and 61 of the intake pipes can move smoothly without reluctance.

Further, as shown in FIG. 3, the swinging arms 52 and 62 are provided with elongated holes 52b and 62b into which the engaging pins 56 of the funnels 51 and 61 are slidably fitted, and the engaging pins. Openings 52c and 62c for inserting 56 into the long holes 52b and 62b, and stopper portions 52d and 62d for preventing the engagement pin 56 from coming off from the long holes 52b and 62b when swinging are formed. Therefore, each swing arm 52, 62 can be easily engaged with each engagement pin 56, and each engagement pin 56 can be removed from each long hole 52b, 62b when each funnel 51, 61 is driven. To be prevented.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In the second embodiment, the connecting rods 823 and 833 of the link mechanisms 820 and 830 in the first embodiment are connected to the intake pipes 41 to 44, 45 to 48 by the pipe length changeable mechanism 5. In the state where the assembly of No. 6 is completed, the adjustment unit 823a for adjusting the variation in the displacement amount of each funnel 51, 61 between the left and right intake pipe rows 4a, 4b, that is, between the left and right banks 2, 3. 823b, 833a, 833b are provided, and the other structure is the same as that of the first embodiment.

Although the two actuators 7 and 70 are used in each of the above embodiments, the present invention is not limited to this, and one actuator is provided between the intake pipe rows 4a and 4b. Alternatively, the rotation of the actuator output shaft may be transmitted to the drive shafts 50 and 60 of the variable tube length mechanisms 5 and 6 via a transmission mechanism to drive the funnels 51 and 61.

In each of the above embodiments, the variable pipe length mechanisms 5 and 6 are used as the movable intake mechanism. However, the intake pipe of each cylinder is composed of two intake pipes as the variable intake mechanism. A mechanism for opening and closing one of the intake pipes may be used.

As described in detail above, according to the variable intake system for a multi-cylinder engine according to the present invention (Claim 1), the intake pipe of each cylinder has a variable intake mechanism for changing the intake efficiency, A variable intake system for a multi-cylinder engine configured such that the driving force of an actuator is transmitted via a transmission member to drive the movable member of each variable intake mechanism to change the intake member of each intake pipe. A drive shaft which is integrated so as to extend over the entire multi-cylinder and is rotatably supported by a support portion of each intake pipe, and a shaft to which the drive force is transmitted via a transmission mechanism; And a swing member that swings by the rotation of the drive shaft to drive each movable member, and a connecting portion between each swing member and the drive shaft is tapered by tightening a fastening nut. Tables that fit together With a structure that is provided with a biasing member that serves as a power fitting portion and that biases each of the swinging members toward the minimum or maximum pipe length position, the swinging member of each cylinder is in a state before tightening the fastening nut. Is urged by the urging member and held at the minimum or maximum movable position side, the movable member of each intake pipe is automatically adjusted to the initial position, and if the fastening nut is tightened in this state, While the movable member is held at the initial position, the rocking members and the drive shaft are connected by fitting their tapered portions, so that the rocking center of each rocking member is relative to the axis of the drive shaft. Aligned automatically. Therefore, it is possible to easily adjust the initial position of the movable member of each cylinder, and it is possible to prevent the movement of the movable member from varying among the cylinders.

Further, according to the variable intake system for a multi-cylinder engine according to the present invention (claim 2), the rocking members are arranged in two intake pipes of each cylinder on both sides of each intake pipe. With the configuration in which the two swinging members of each intake pipe are fastened by the fastening nuts having mutually opposite screws, the two swinging members of each cylinder are fastened by the fastening nuts having mutually opposite screws. Therefore, the two fastening nuts of each intake pipe are tightened in the same direction, and the two fastening nuts become a double nut. Therefore, the pipe length varying mechanism can be easily attached to each cylinder, and the loosening of each fastening nut can be prevented.

Further, according to the variable intake system for a multi-cylinder engine according to the present invention (Claim 3), the drive shaft is supported by bearings of the intake pipes via bearings. The movable member of each cylinder is smoothly driven without reluctance. Therefore, in a multi-cylinder engine having many cylinders, it is possible to ensure smooth movement of the movable member of each cylinder.

[Brief description of drawings]

FIG. 1 is a view showing a main part of a variable intake device according to a first embodiment of the present invention, which is an enlarged view of a part of FIG. 5 and a part of which is shown in cross section.

FIG. 2 is a schematic configuration diagram showing a V-type engine using the variable intake system according to the first embodiment of the present invention.

FIG. 3 is a partially enlarged view of the variable intake device shown in FIG. 2, showing a state in which the funnels of each intake pipe are at the minimum pipe length position.

FIG. 4 is an enlarged view similar to FIG. 3, showing a state in which the funnel of each cylinder is at the maximum pipe length position.

FIG. 5 is a plan view of an intake system showing a state in which a funnel of each cylinder is removed.

FIG. 6 is a diagram showing a structure in which two actuators and a drive shaft of one intake pipe array are connected by a link mechanism.

FIG. 7 is a view showing a variable intake device according to a second embodiment of the present invention, and is a view showing a state in which the funnels of the intake pipes are at the minimum pipe length position as in FIG.

FIG. 8 is a view similar to FIG. 7, showing a state in which the funnel of each intake pipe is at the maximum pipe length position.

FIG. 9 is a view showing a variable intake device according to a second embodiment of the present invention, which is similar to FIG.

[Explanation of symbols]

 1 Variable Intake Device 5, 6 Pipe Length Variable Mechanism (Variable Intake Mechanism) 7, 70 Actuator 8, 80 Transmission Mechanism 41-48 Intake Pipe 41a-48a Intake Pipe Support 50, 60 Drive Shaft 51, 61 Funnel (Movable Member) 52, 62 rocking arm (rocking member) 52a taper part of rocking arm 510b taper part of drive shaft 510c left screw 510d right screw N1, N2 fastening nut

Claims (3)

[Scope of utility model registration request] 1. A variable intake mechanism for changing intake efficiency is provided in an intake pipe of each cylinder, and a movable member of each variable intake mechanism is driven by transmitting a driving force of an actuator through a transmission mechanism. In a variable intake system in a multi-cylinder engine configured to change the intake characteristic of each intake pipe, the drive force is transmitted through a transmission mechanism and is integrated so as to extend over the entire multi-cylinder. A drive shaft rotatably supported by a support portion of each intake pipe, and a swing member provided on each intake pipe and swinging by the rotation of the drive shaft to drive each movable member. The connecting portion between each rocking member and the drive shaft is a taper fitting portion in which the taper portions are fitted by tightening a fastening nut, and each rocking member is biased toward the minimum or maximum movable position. Is provided with a biasing member A variable intake system for a multi-cylinder engine, characterized in that 2. The fastening nut, wherein two rocking members are arranged on both sides of each intake pipe in the intake pipe of each cylinder, and the two rocking members of each intake pipe are reverse screws to each other. Device according to claim 1, characterized in that it is fastened by means of: 3. The device according to claim 1, wherein the drive shaft is supported by a support portion of each of the intake pipes via a bearing.