JP2736630B2 - Air funnel for intake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an air funnel connected to an intake port of a carburetor or the like.

[0002]

2. Description of the Related Art As is well known, a carburetor is a device that feeds fuel into an engine (cylinder) in the form of a mist. An air funnel is connected to an intake port, that is, an opening on the upstream side. An air funnel is generally a cylindrical component similar to a funnel, and has a function of efficiently sending air that has passed through an air cleaner to a carburetor.

The air funnel has the effect of increasing the output during low-speed rotation of the engine as the length of the pipe increases, and increasing the output during high-speed rotation as the length of the pipe increases, due to the pulsation of intake air and the like. Therefore, conventionally, in order to improve the output characteristics of the engine at low speed and at high speed, an air funnel whose length can be changed has been developed. JP-A-5-272
The device described in Japanese Patent Publication No. 340 also has a variable length of the air funnel tube from the same viewpoint.

FIG. 5 is a sectional view showing the structure of an air funnel 1 'and the like described in that publication. Movable intake pipe (outer pipe) outside of intake pipe (inner pipe) 3 'connected to carburetor 20'
4 'is slidably inserted and its outer tube 4' is driven and
The cable 12 'and pulley 11' connected to the control means (not shown), and the structure of sliding in the longitudinal direction by the action of the swing arm 6 'rotating with the pulley 11' are adopted. In other words, the intake pipe is nested like a telescope so that its length can be changed.

[0005]

The conventional nested air funnel as shown in FIG. 5 is not optimal in the following points. That is, a) Since the outer tube needs to be slidably inserted into the outer side of the inner tube with a small gap, the inner side (sliding portion) must be a true cylindrical surface with a constant diameter. A trumpet-shaped conical surface that is optimal in terms of intake efficiency cannot be obtained. In addition, since considerable mechanical processing accuracy is required for the slide part, etc., it cannot be said that manufacturing is always easy,
It is naturally disadvantageous in terms of cost.

(B) In the case of the two-stage structure as shown in FIG. 5, the total length of the intake pipe including the outer pipe is at most twice as long as the case of only the inner pipe. That is, the ratio of the length of the air funnel tube to the length at the longest time relative to the shortest time is limited to 2 or less, and the output characteristics of the engine cannot be improved very little. If the length is to be changed by a factor of two or more to make the degree of improvement noticeable, three or more inner and outer tubes must be slidably connected. In addition to increasing the manufacturing disadvantage described above, the outer diameter of the air funnel is increased, which may lead to inconvenience in mounting space when a plurality of air funnels are provided together with the vaporizer.

(C) When the outer pipe is extended beyond the inner pipe, it is inevitable that a step is formed at the joint between the two pipes as shown in FIG. It is not so good for air filling efficiency. The inner pipe or the like needs a certain thickness or more (for example, about 1 mm or more) in order to smoothly perform machining, so that a step corresponding to the thickness is formed in the air funnel in any state within the length change range. It is created inside.

[0008] The object of the present invention is to provide
An object of the present invention is to provide an air funnel which is easy to manufacture, has a large length change range, and has no step on the inner surface, and has a good intake efficiency.

[0009]

According to the first aspect of the present invention, there is provided an air intake funnel, wherein a plurality of ribbon-shaped (band-shaped) elastic thin plates are wound around a plurality of times to form a cylinder whose length can be changed. It was a tube. In addition, in order to smoothly change the length while keeping the leakage of intake air in this pipe small, in a state where it is used as a pipe, it was wound up by 1/100 mm between each thin plate adjacent inside and outside.
It is preferable that a gap of a table (0.01 to 0.1 mm) is formed.

The air funnel configured as described above has the following features in operation. 1) A cylinder formed by winding a ribbon-shaped (strip-shaped) thin plate having a smooth surface with elasticity a plurality of times can be freely changed in length without special machining. That is,
The length is changed by moving the center end and the outer end of the cylinder toward or away from each other (that is, in a direction parallel to the axis of the cylinder, or while adding a circumferential displacement).
It can be realized only by relative movement. Therefore, the air funnel is easy to manufacture and the cost is low.

2) If the tube is connected to the vaporizer so that the outer end can move away from the vaporizer,
A trumpet-shaped conical surface whose inner diameter becomes smaller as it is closer to the vaporizer is formed. Therefore, the intake efficiency for the carburetor is high.

3) Depending on the width and the number of windings of the elastic thin plate, the ratio of the longest length to the shortest length can be considerably increased. Therefore, it is possible to significantly improve the output characteristics of the engine.

4) Since the thin plate has elasticity,
After changing the length of the cylinder, it exhibits a self-restoring effect, and the length of the tube returns smoothly. That is, there is no need to provide a separate spring for restoring the length or smoothing the movement, and the structure can be simplified accordingly.

5) The elastic thin plate whose thickness has been previously set is wound around a cylinder, and the thin plate is not machined after being formed into a cylinder. Is not required, so that the sheet can be quite thin. When a thin thing is rolled up, the level difference between adjacent parts becomes smaller and the inner surface of the cylinder becomes closer to a smooth surface, so that the flow of intake air does not disturb and the air cleaner is filled with air. It is efficient. Further, when the plate is thin, the outer diameter of the air funnel can be reduced, and there is an advantage that it can be easily mounted on a motorcycle or the like.

According to a second aspect of the present invention, the intake air funnel has a thickness of 0.05 to 0.5 m.
m, spring steel having a width of 5 to 30 mm as the above elastic thin plate,
This is wound 5 to 50 times to form the above cylinder. These numerical values are only a desirable range for exhibiting the desired effect. For example, when the number of windings is 5 times or less (2 times or more) or 50 times or more, the above and the following effects are completely absent. Not that.

The air funnel according to the second aspect has the following effects in addition to the above-mentioned 1) to 5). 6) Since spring steel is used as the elastic thin plate, it is easy for the cylinder to have self-restoring properties based on its elasticity, and even if a very thin one is used, it gives the cylinder the necessary rigidity, strength, and durability. be able to.

7) The thickness of the spring steel is 0.05 to 0.5
mm, there is no inconvenience that the cylinder does not have the required rigidity due to being too thin.On the other hand, because it is too thick, there is a step on the inner surface of the pipe, which disturbs the intake air flow, and it is necessary to change the length There is no inconvenience such as excessive force. In addition, since there is a standard product (commercially available product) for a spring steel having such a thickness, it is advantageous in terms of manufacturing cost.

8) An elastic thin plate having a width of 5 to 30 mm
Since it is wound only 0 times to form a cylinder, it has a length that can be actually used as an air intake funnel for automobiles and motorcycles, etc., and constitutes a practical tube that can change its length at a desired magnification. can do. That is, it is possible to configure an air funnel whose length can be changed at a large magnification (that is, a wide range) such that the shortest length of the tube is 30 mm or less and the longest length is 3 to 4 times or more of the shortest length. It is. In addition, if the number of windings (number of windings) is as described above, the outer diameter of the air funnel does not become too large. If the number of windings is appropriately selected from the above range in accordance with the width of the thin plate within the above range, a sufficient overlap margin between the inner and outer adjacent thin plates even when the cylinder is extended long (the portion where the adjacent thin plates overlap) Since the width measured in the width direction of the thin plate, that is, the dimension measured in the axial direction of the cylinder) can be secured, it is easy to prevent the leakage of the intake air.

According to a third aspect of the present invention, there is provided an intake air funnel according to the first or second aspect, wherein: a) an annular member for connecting an end of the elastic thin plate on the center side of the cylinder to a carburetor. On the other hand, the outer end of the cylinder of the elastic thin plate has a pin on the outer peripheral surface and an annular member on the upstream side having a guide hole in a direction parallel to the axis of the cylinder (open end). B) a guide rod extending parallel to the axis of the cylinder is fixed to the former annular member and passed through the guide hole of the latter annular member, and c) the number of revolutions (that is, rotational speed) of the engine is reduced. A swing arm whose angle is changed via a reflecting control means is engaged with a pin of the latter annular member.

In this air funnel, the length of a cylinder serving as an intake pipe is changed as follows. The control means of the above c) changes the angle of the swing arm and moves the pin with which it is engaged. Since the control means reflects the number of rotations of the engine, the angle of the swing arm and the amount of movement of the pin also correspond to the number of rotations. With the movement of the pin, the upstream annular member shown in a) moves in the longitudinal direction of the cylinder. The pin is attached to the upstream annular member as in a), and the annular member is guided by the guide rod in b) in a direction parallel to the axis of the cylinder. Is moved, the annular member moves parallel to the axis of the cylinder, that is, in the longitudinal direction of the cylinder. The movement of the annular member on the upstream side changes the length of the cylinder, that is, the intake pipe. As described in a) above, the upstream annular member is fixed to the outer end of the elastic thin plate, and the center end of the cylinder of the elastic thin plate is fixed to another annular member and connected to the vaporizer. When the annular member on the upstream side moves parallel to the axis of the cylinder, the cylinder made of the elastic thin plate changes its length while forming a trumpet-shaped conical surface on the upstream side of the vaporizer. From the above,
Since the length of the intake pipe changes according to the engine speed, this air funnel can improve the output characteristics of the engine to increase the output during high-speed rotation and low-speed rotation. .

In the case of this air funnel, since the upstream annular member connected to the elastic thin plate moves along the guide rod of b), the length of the cylinder can be changed smoothly, , The entire shape and the like are maintained without being distorted. However, because the elastic thin plate cannot be displaced in the circumferential direction due to the guide rod, the cylinder can be smoothly changed in length without causing tight tightening. It is necessary to take a sufficient number of turns and provide an appropriate gap between the wound inner and outer thin plates.

[0022]

1 to 4 show an embodiment of the present invention. 1 is a longitudinal sectional view showing the air funnel 1 together with the carburetor 20 (a sectional view taken along the line II in FIG. 2). FIG. 2 is an overall view showing the air funnel 1 and the carburetor 20 as viewed from the front. (B) is a side view showing the drive mechanism of the air funnel 1 (viewed in the directions of arrows aa and bb in FIG. 2), and FIG. 4 is a view showing a case where the air funnel 1 is used. 4 is an output curve of the engine.

This embodiment shown in the drawings relates to an intake air funnel provided in a motorcycle (not shown) for racing equipped with a four-cylinder engine (not shown). As shown in FIG. 2, one air funnel 1 is connected to each upstream opening of a carburetor 20 (a so-called VM type), and four sets thereof are assembled together and an air cleaner (shown in FIG. 2). Box 25 that leads to
The whole is covered by. It goes without saying that the opening on the downstream side of the carburetor 20 (the left end portion in FIG. 1) is connected to the engine via another pipe (not shown).

The respective air funnels 1 connected to the upstream side of the carburetor 20 are constructed as follows.

First, as shown in FIG. 1 (in the figure, the upper half shows the longest state of the air funnel 1 and the lower half shows the shortest state), it becomes the intake pipe of the air funnel 1. In the part, a cylinder formed by winding a thin steel strip 2 is incorporated. As the steel strip 2, stainless steel spring steel (JIS-G431) which is rich in elasticity and excellent in strength and durability is used.
"Stainless steel strip for springs" SUS304-C specified in 3
SP) was used. The steel strip 2 has a smooth surface, the dimensions are 0.1 mm in thickness and 9.1 mm in width, and the innermost portion (the center side of the cylinder) has a diameter of about 45 mm and is wound 20 times in a circle. . The steel strip 2 was wound so as to have a gap of about 0.03 mm between adjacent portions inside and outside, so that the outermost diameter was about 50 mm. The innermost end of the steel strip 2 is bonded to an annular flange member 3 having a connection surface with the carburetor 20 with an adhesive (for example, an epoxy-based adhesive; not shown), and the outermost end is formed. Is formed on an annular open end member 4 having a smooth curved surface extending outward.
Again, they are joined with an adhesive (same as above; not shown).
Therefore, if the flange member 3 is connected to the carburetor 20 and the open end member 4 is moved in the axial direction of the cylinder, the cylinder is lengthened as shown in the upper half of the figure, or the cylinder is formed as shown in the lower half of the figure. Can be shortened. Since the steel strip 2 is deformed within the range of elasticity and the cylinder expands and contracts, the surface of the steel strip 2 is smooth, and an appropriate gap exists between adjacent portions inside and outside the steel strip 2 as described above. Expansion and contraction can be performed smoothly.

The shortest overall length L ₁ of the air funnel ₁ is 2
0 mm, the overall length L ₂ at the time of maximum and 65 mm, was set large magnification between them three or more, does not adversely inconvenience leaks air from the side surface of the cylinder in either state. At the shortest time when the almost entire width of the steel strip 2 overlaps the inner and outer adjacent parts (the steel strip 2 is wound in this way in a natural state), and also at the longest time, between the parts of the steel strip 2. This is because a sufficient overlapping margin is secured (see the enlarged portion in FIG. 1). That is, since the steel strip 2 is sufficiently wound as 20 times, even if the cylinder is lengthened by (65−20) mm = 45 mm, the sliding amount per one turn of the steel strip 2 is small.
45/20 ≒ 2.3 mm, so that an overlap of (9.1-2.3) mm = 6.8 mm is secured between the parts even at the longest. And over this width,
Since there is only a small gap as described above, it is difficult for the intake air to leak across the gap.

The force for changing the length of the cylinder directly acts only on both ends of the steel strip 2 via the flange member 3 and the open end member 4, but the force is applied to the entire cylinder. , The entire cylinder expands and contracts almost uniformly, including the middle part sandwiched between the members 3 and 4. The force of the length change is applied to the entire cylinder because the steel strip 2 is a spring steel having a high elasticity and is easy to transmit the force. In addition, as described above, the surface of the steel strip 2 is smooth and the inner and outer This is because forces and displacements are smoothly transmitted due to the presence of an appropriate gap between adjacent portions.

In addition, a ring 3a having a smooth curved surface extending outward is attached to the back surface of the flange member 3 (the side not connected to the vaporizer 20). This ring 3
Since the curved surface of a is substantially parallel to the curved surface inside the open end member 4, the cylinder is in the shortest state as shown in the lower half of FIG. When the (left end) touches this curved surface, the inner surface of the cylinder made of steel strip 2
Smooth curved surface following the inner surface of the open end member 4 (however, steel strip 2
There is a step depending on the thickness of the air), which makes the inflow of intake air smooth.

In the air funnel 1, a drive mechanism for changing the length of the above-mentioned pipe (cylinder) made of a steel strip 2 or the like is configured as shown in FIG.

That is, first, as shown in FIG. 3A, the flange member 3 is attached to the carburetor 20, and the guide rod 5 is fixed on the flange member 3 in parallel with the axis of the cylinder. The guide rod 5 is passed through the guide hole 4b of the open end member 4 connected to the side. Guide rod 5
As shown in FIG. 2, there are two air funnels 1 per unit, and their tip portions (portions protruding from the opening end member 4) are connected by a plate 5a (FIG. 3A, not shown in FIG. 2). In order to prevent it from falling down. Guide rod 5
Since the open end member 4 is guided by this, the cylinder can change its length in the axial length direction smoothly and straight without losing its shape.

Then, on the outer peripheral surface of the open end member 4, FIG.
The swing arm 6 whose angle can be freely changed about the support shaft 10 is engaged with the pin 4a attached as shown in FIG. Pin 4a
As shown in FIG. 2, since two adjacent open end members 4 are connected to each other, four air funnels 1 are provided while two swing arms 6 are provided. As shown in FIG. 3A, a bifurcated slightly long claw 6a is formed at the tip of the swing arm 6, and the pin 4a is engaged therebetween.
The open end member 4 can be moved linearly along the guide rod 5 despite the rocking motion of the. In addition, regarding the support shaft 10, each carburetor 20 is formed by the shaft 8 and the bolt 7a on which the four carburetors 20 are assembled.
The bracket 7 is fixed to the bracket 7, and the front ends of the four brackets 7 are penetrated in series, and the support shaft 10 is rotatably provided. Each swing arm 6 is fixed on the support shaft 10 so as to rotate integrally with the support shaft 10.

The rotation (swing) of the swing arm 6 is performed together with the support shaft 10.
2 (b), the pulley 11 is fixed on the support shaft 10 (near the center as shown in FIG. 2), and the pulley 11 is connected to the operation motor 15 via the control cable 12 as shown in FIG.
Connected to The motor 15 is an engine (not shown)
The drive pulley 16 is rotated by an angle corresponding to the engine speed in response to a signal from a control means (not shown) for outputting an output according to the engine speed. Motor 1
The drive direction of the pulley 16 and the arm 6 shown in FIG. 3A by using the cylinder 5 is such that the cylinder made of the steel strip 2 is lengthened when the engine speed is low, and when the engine speed is high as described later. Is the direction to shorten.

With the above configuration, FIGS.
The air funnel 1 of FIG. 3 functions as follows according to the change in the engine speed. While the rotation speed is low, the motor 15 (FIG. 2) receives the output signal from the control means (not shown) and moves the swing arm 6 of FIG. ). Arm 6 is steel strip 2
Since it is engaged with the pin 4a of the open end member 4 coupled with the steel strip 2, the cylinder is lengthened against the elasticity of the steel strip 2 to maintain the natural state, and that state is maintained. When the engine speed increases, the motor 15 (FIG. 2) rotates the arm 6 to the left in the figure, and shortens the cylinder of the steel strip 2 according to the output of the control means. The arm 6 is engaged with the cylinder only through one point of the pin 4a. However, the cylinder is short because the steel strip 2 forming the cylinder has a self-restoring force to return to a natural state. Transition to the state smoothly. As described above, the ratio between the length _{L 1} of the length _{L 2} and the shortest time during the longest air funnel 1 65:20 i.e. 3.25: 1
It is. From the viewpoint of preventing the engine from causing a breathtaking phenomenon, the control means is set so as to shorten the length of the air funnel 1 quickly during acceleration.

When the length of the air funnel 1 is changed in a wide range as described above in accordance with the number of revolutions, the output of the engine is drawn high at each of the low speed and the high speed. The point is, for example, the longest time (length L ₂ ) of the air funnel 1
The output characteristics of the engine at the shortest time (length L ₁ ) can be explained with reference to FIG. As shown,
When the air funnel 1 is extended to the longest (L ₂ ), the engine is of a low speed type and exhibits a maximum output at a relatively low speed, while when the air funnel 1 is contracted to the shortest (L ₁ ), the engine is of a high speed type.
Demonstrates high output in the high rotation range. This air funnel 1
In this case, since the range in which the length changes is wide, there is a great difference between the two characteristics. According to the air funnel 1 of the embodiment, the two characteristics that are distinguished in this way and the intermediate characteristics between the two can be appropriately selected according to the rotational speed, so that a high output can be provided to the engine over a wide rotation range. It can be demonstrated.

Although an embodiment has been described above, the present invention is not limited to this embodiment. For example, the present invention can be implemented as follows.

A) As means for driving the swing arm 6 (FIG. 3A) and the like, a motor (reference numeral 15 in FIG. 2) is used.
It is also possible to use another actuator instead of. That is, a hydraulic motor, a pneumatic motor, a solenoid, a mechanical governor, or the like can be used. It is not indispensable that the length of the air funnel can be continuously changed as in the above embodiment, and an on / off type actuator for switching between the longest and shortest states may be used.

(B) Instead of the steel strip 2 (FIG. 1), the cylinder may be formed by using an elastic thin plate made of another material such as a non-ferrous metal strip or a ribbon sheet made of plastic or the like. This is because, in principle, any material can be used as long as it can change the required length, exhibit a restoring force, and have durability and the like.

(C) There is no reason to limit the shortest state of the cylinder formed of the elastic thin plate to the natural state. It may be the longest in the natural state or an intermediate state between the longest and the shortest in the natural state.

D) In the above embodiment, the elastic thin plate (steel strip 2)
While the width of the cylinder is kept constant (9.1 mm), a ring 3a is attached to the back surface of the flange member 3 so that a smooth curved surface can be formed on the inner surface of the cylinder at the shortest time, but this is not essential. For example, even if the ring 3a or the like is not attached and the width of the elastic thin plate is changed depending on the portion to form the same curved surface at the shortest time, the effect of smoothing the inflow of the intake air can be obtained.

E) Both ends of the elastic thin plate and the annular member (flange member 3 and open end member 4) are connected not only by an adhesive but also by various means such as welding, pinning, or caulking. It can be carried out.

F) Although the air funnel connected to the carburetor has been described above, it may be connected to a fuel injection device or the like.

(G) The elastic thin plate forming the cylinder may be practically used if at least two sheets overlap each other.

[0043]

The intake air funnel of the first aspect has the following effects.

1) Since a cylinder having a variable length, which is an intake pipe, can be formed without performing special machining, it is easy to manufacture and advantageous in cost.

2) Since a trumpet-shaped conical surface whose inner diameter becomes smaller as it is closer to the vaporizer can be formed on the inner surface of the tube, the intake efficiency for the vaporizer is high.

3) Since the magnification of the maximum length to the minimum length can be considerably increased, the output characteristics of the engine are significantly improved.

4) Based on the elasticity of the thin plate, the pipe moves smoothly and restores its length without a separate spring or the like, so that the structure of the air funnel 1 is simplified.

5) Since the elastic thin plate needs to be quite thin, a surface having a small step and close to a smooth surface can be formed on the inner surface of the tube, and the air cleaner can be efficiently filled with air. Further, since the plate is thin, the outer diameter as an air funnel is small, and it is easy to mount it on a motorcycle or the like.

The air funnel of claim 2 has the following effects in addition to the above. 6) Since the elastic thin plate is made of spring steel, the self-restoring property of the cylinder is strong. In addition, although it is a thin plate, it has the rigidity and durability required for an air funnel, so that it is preferable for use.

7) Regarding spring steel, there is no inconvenience that the cylinder is not provided with rigidity because it is too thin, or that the intake air is disturbed due to a step on the inner surface of the pipe because it is too thick. In addition, standard products (commercial products) can be used, which is advantageous in manufacturing.

8) It is possible to construct a desirable air funnel having a length that can be actually used as an air intake funnel for an automobile, a motorcycle, or the like, and that can change its length at a large magnification. In this air funnel 1, there is no inconvenience that the outer diameter becomes too large, and leakage of intake air can be easily prevented.

In the case of the intake air funnel according to the third aspect, 9) since the upstream annular member connected to the elastic thin plate moves along the guide rod, the length of the cylinder can be smoothly changed. In addition, the entire shape and the like are maintained without being damaged even by long-term use.

10) Since the length is automatically changed according to the number of revolutions, the output of the engine at low speeds and high speeds can be appropriately improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an air funnel 1 according to an embodiment of the present invention together with a carburetor 20, and is a II sectional view in FIG.

FIG. 2 Air funnel 1 and carburetor 2 assembled together
FIG. 2 is an overall view showing a state where 0 and the like are viewed from the front.

FIG. 3 is a side view showing a driving mechanism of the air funnel 1,
3 (a) and 3 (b) are a view taken along arrows aa and bb in FIG. 2, respectively.

FIG. 4 is an output curve of an engine using the air funnel 1;

FIG. 5 is a longitudinal sectional view showing a conventional air funnel.

[Explanation of symbols]

 Reference Signs List 1 air funnel 2 steel strip (elastic thin plate) 3 flange member (annular member) 4 open end member (annular member) 4a pin 4b guide hole 5 guide rod 6 swing arm 20 carburetor

Claims (3)

(57) [Claims] 1. An intake air funnel, wherein a ribbon having a variable length is formed by winding a ribbon-shaped elastic thin plate a plurality of times, and this is used as an intake pipe. 2. The thickness is 0.05 to 0.5 mm and the width is 5 to 5.
30 mm spring steel is used as the above-mentioned elastic thin plate.
2. The intake air funnel according to claim 1, wherein the cylinder is formed by being wound only zero times. 3. An end of the elastic thin plate on the center side of the cylinder is connected to an annular member for connection to a carburetor.
The outer end of the cylinder of the elastic thin plate has a pin on the outer peripheral surface and is coupled to an upstream annular member provided with a guide hole in a direction parallel to the axis of the cylinder, and extends parallel to the axis of the cylinder. The guide arm is fixed to the former annular member and passed through the guide hole of the latter annular member, and the swing arm whose angle is changed through control means for reflecting the number of revolutions of the engine is connected to the pin of the latter annular member. The intake air funnel according to claim 1, wherein the air funnel is engaged with the intake air funnel.