JPH0717783Y2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of an intake system of an engine which enhances charging efficiency by utilizing a dynamic effect of intake.

(Prior Art) In order to improve the charging efficiency by utilizing the dynamic effect of intake air, particularly resonance supercharging, there is one as shown in Japanese Patent Laid-Open No. 56-115818. That is, the inside of the surge tank is defined by the partition wall into two first and second intake expansion chambers, and one cylinder group whose ignition order is not continuous is located in the first intake expansion chamber and whose ignition order is not continuous. The other cylinder group is made to communicate with the second intake expansion chamber. Then, in order to obtain the resonance supercharging over a wide operating range of the engine, that is, in order to adjust the tuning condition of the intake system for the resonance supercharging in response to changes in the operating state of the engine, it is arranged in the surge tank. The on-off valve connects and disconnects the two intake expansion chambers. More specifically, for example, the on-off valve is closed (closed) in the low engine speed range, and both intake expansion chambers are connected via a long system path such as a confluence formed in the common intake pipe portion on the upstream side of the surge tank. On the other hand, in the high engine speed range, the on-off valve is opened (communicated) so that both intake expansion chambers communicate with each other through an extremely short system path. The passage length is switched.

(Problems to be Solved by the Invention) By the way, one of the problems in manufacturing is how to easily install the on-off valve in the surge tank. Above all, it is desired that the surge tank be made as an integrally molded product of plastic or light alloy, and even if the surge tank is disassembled, it is extremely troublesome to assemble a small opening / closing valve in a narrow surge tank. .

From this point of view, it is conceivable that the on-off valve is rotatably held in the valve housing to form one unit body together with the valve housing, and this unit body, that is, the valve housing, is incorporated into the surge tank from the outside of the surge tank in an insertable manner. . However, in the case where this unit type is incorporated from the outside, how to secure the seal between both intake expansion chambers due to mounting of the valve housing, and how to position the valve housing, that is, prevent rattling, especially in the surge tank, How to do it becomes a problem.

Therefore, the object of the present invention is to assume that the on-off valve is held in the valve housing, and the on-off valve is incorporated into the surge tank by mounting the valve housing from the outside of the surge tank. An object of the present invention is to provide an intake device for an engine capable of performing positioning of the valve housing and sealing between the intake expansion chambers when the valve housing is mounted.

(Means and Actions for Solving Problems) In order to achieve the above object, the present invention has the following configuration. That is, the inside of the surge tank is defined by the partition wall into a first intake expansion chamber connected to one cylinder group whose ignition order is not continuous and a second intake expansion chamber connected to another cylinder group whose ignition order is not continuous to each other. An intake device for an engine in which an opening / closing valve for connecting and disconnecting the two intake expansion chambers to switch the equivalent communication passage length is provided in the surge tank, A fitting recess is formed along the partition wall from the outside of the tank, into which a valve housing that rotatably holds the on-off valve is fitted, and the fitting recess has a conical shape with the same angle as the drill cutting edge. An inner inner surface and an inner surface that is continuous with the inner inner surface and has a cylindrical shape that is substantially the same as the drill diameter, and an inner end surface and an outer surface of the valve housing fitted in the fitting recess are Inner depth of the fitting recess And the inner end surface of the valve housing is seated on the inner rear surface of the fitting recess, and the thickness of the partition wall is such that the valve housing is fitted. The thickness of the valve housing is equal to or larger than the thickness of the valve housing.

With such a configuration, the on-off valve can be easily assembled in the surge tank simply by fitting the valve housing holding the valve housing to the fitting recess from the outside of the surge tank. The fitting recess formed in the surge tank can be extremely easily formed by drilling.

Further, the valve housing outer peripheral surface of the portion inserted into the fitting recess has a shape that matches the inner surface shape of the fitting recess formed by the drilling process.
The surge tank is securely held in the surge tank without rattling. That is, the outer surface of the valve housing and the inner surface of the fitting recess in the surge tank are both cylindrical in shape corresponding to the outer peripheral shape of the rotary drill during drilling, and are fitted to the inner end surface of the valve housing. Both the inner surface of the recess and the inner surface of the recess will have a conical shape with an apex angle corresponding to the cutting edge angle of the drill. Therefore, in combination with seating the inner end surface of the valve housing on the inner surface of the fitting recess. The rattling of the valve housing is surely prevented, and the seal leakage between the valve housing and the fitting recess (inner surface), that is, the seal leakage between the intake expansion chambers is also prevented. Even if a gap is created between the fitting portion of the valve housing and the fitting recess, the fitting recess is formed by drilling, while the inner end surface and the outer surface of the valve housing are
By having a shape that matches the shape of the inner back surface and the inner side surface of the fitting recess, the seal cross section between the fitting portions of the valve housing and the fitting recess is flat over the entire length in the fitting direction. Since the curved surface is used instead of the curved surface, the curved surface effectively suppresses the pressure wave (pulsation) having straight-line propagation properties (contact between the valve housing and the inner surface of the fitting recess via the curved surface). Sealing effect).

Moreover, as described above, the inner recess surface of the fitting recess and the inner end surface of the valve housing are conical so as to match each other, and the inner surface of the fitting recess and the outer surface of the valve housing match each other. Therefore, even when the valve housing is mounted on the valve housing, the valve housing may be tilted (rotated) about the axis of the fitting recess with respect to the normal state. , Make sure that the state of the surface contact between the inner back surface of the fitting recess and the inner end surface of the valve housing and the surface contact between the inner surface of the fitting recess and the outer surface of the valve housing are the same as in the normal state. be able to. For this reason,
Even if the valve housing is mounted with tilting (rotating) with respect to the normal state due to the play of the mounting bolts, etc., the valve housing and the fitting recess are not attached. A seal can be obtained between the fitting parts, and the sealability is always ensured without depending on the seal member.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1 and FIG. 2, an engine 1 which is an OHC type V-type 6 cylinder has two banks 2A and 2B on the left and right, and the left bank 2A has one end side in the engine output shaft direction (first From the lower end side in the figure) to the other end side, the odd numbered cylinders 3A, 1st, 3rd, and 5th are configured, and similarly, the 2nd is in the right bank 2B,
The even numbered cylinders 3B, numbered 4 and 6, are configured. The ignition order of these six cylinders 3A and 3B is, for example, 1
In the order of No. 2, No. 3, No. 6, No. 5, No. 5, and No. 4, the odd-numbered cylinders 3A of the left bank 2 constitute one cylinder group in which the ignition order is not continuous, and The even-numbered cylinders 3B of the bank 3 constitute another cylinder group whose ignition order is not continuous.

A surge tank 4 is disposed above the V bank central space X formed between the left and right banks 2A and 2B. The surge tank 4 extends in the front-rear direction, that is, the engine output axis direction, and the inside thereof is divided into a first intake expansion chamber 6A and a second intake expansion chamber 6B by a partition wall 5 extending in the engine output axis direction. ing. In this embodiment, a comparatively long communication passage 5a extending in the engine output shaft direction is formed in the partition wall 5, and the intake passages 6a are formed by the communication passage 5a.
And 6B are in constant communication. Such a long communication passage
5a is set to a length that satisfies the resonance effect synchronization condition in the low engine speed region.

Three intake / exhaust ports 7A or 7B are formed on each of the left and right side walls of the surge tank 4, and the first intake expansion chamber is formed.
The intake / exhaust port 7A opening to 6A is connected to the intake port 9A of the cylinder 3A in the left bank 2A via the independent intake pipe 8A. Further, the intake / exhaust ports 7B opening to the second intake expansion chamber 6B are connected to the intake port 9B of the cylinder 3B in the right bank 2B via the independent intake pipes 8B. As described above, the intake expansion chambers 6A and 6B are used for the banks 2A and 2B on the far side, respectively. Therefore, the independent intake pipes 8A and 8B are once provided from the left and right sidewalls of the surge tank 4, respectively. After extending away from each other, it is folded back approximately 180 ° and formed as long as possible so as to pass under the surge tank 4 and connect to the intake port 9A or 9B. is there.

Further, on the rear wall of the surge tank 4, one first intake air inlet 10A opening to the first intake expansion chamber 6A is formed and one second intake air inlet opening to the second intake expansion chamber 6B is formed.
10B is formed. Then, the downstream portion of one common intake pipe 11 is branched into two first and second branch pipes 11A and 11B, and the first branch pipe 11A is connected to the first intake inflow port 10A,
Further, the second branch pipe 11B is connected to the second intake air inlet 11B. As a result, the intake air from the common intake pipe 11 is branched into the branch pipes 11A and 11B from the branch portion (confluence portion) Y, is branched and introduced into both the intake expansion chambers 6A and 6B, and then, Each cylinder 3A in the left bank 2A from the first intake expansion chamber 6A
To the respective cylinders 3B in the right bank 2B from the second intake expansion chamber 6B. Such a branch pipe 11A and 1
A communication length between the intake expansion chambers 6A and 6B via 1B is longer than that of the communication passage 5a.

12A and 12B in FIG. 1 are exhaust ports, and 13A and 1B in FIG.
3B is a fuel injection valve.

The partition wall 5 in the surge tank 4 is provided with a communication port 21 (which also serves as a fitting recess described later) in the vicinity of the front wall thereof. The communication port 21 communicates with the intake expansion chambers 6A and 6B at a shorter distance than the communication passage 5a and is opened / closed by an opening / closing valve 22.

With the above configuration, if the on-off valve 22 is now closed,
Both intake expansion chambers 6A and 6B are communication passages formed in the partition wall 5.
The long path through 5a allows communication, and the resonance supercharging synchronization condition is satisfied in the low engine speed region. Further, when the on-off valve 22 is opened, the intake expansion chambers 6A and 6B are communicated with each other by a short path through the communication port 21, and the synchronization condition of resonance supercharging is satisfied in the high engine speed region (resonance supercharging Therefore, the length of the communication passage that connects the intake expansion chambers 6A and 6B, that is, the equivalent communication passage length depends on the shorter communication passage).

The on-off valve 22 is a valve housing, as shown in FIG.
It is supported by 23 so as to be rotatable and non-displaceable in the axial direction. The valve housing 23 is assembled to the surge tank 4 so that the opening / closing valve 22 is located at the communication port 21 through the mounting hole 24 formed in the front wall of the surge tank 4. A flange portion 23a integrally formed with the housing 23 is fixed to the surge tank 4 by a bolt (not shown) or the like.

The valve housing 23 is fitted into the fitting recess 25 formed in the partition wall 5 through the mounting hole 24, in other words, constitutes a part of the partition wall 5, and the fitting recess 25 has a radius of r
The mounting hole 24 is formed by drilling using a large-diameter drill. Therefore, the inner side surface 25a of the fitting recess 25 is formed into a cylindrical shape around the rotation axis O at the time of drilling, and the inner rear surface 25b has an apex angle θ corresponding to the cutting edge angle of the drill. Formed as a cone having On the other hand, the valve housing 23 also has the fitting recess.
It is shaped to match 25. That is, the outer surface 23b of the valve housing 23 along the machining axis O is formed in a cylindrical shape having a radius corresponding to the radius r of the drill with the axis O as the center (see FIG. 5).
Similarly, the inner end face (front end face in the fitting direction) 23 of the valve housing 23
The c is also formed as a cone having an apex angle θ corresponding to the edge angle of the drill (see FIGS. 3 and 7). In such a valve housing 23, the inner end surface 23c is seated on the inner rear surface 25b of the fitting recess 25 at the time of fitting into the fitting recess 25, and the communication port 21, that is, the communication opening at the fitting recess 25 portion. Has 26. The opening / closing valve 22 is located in the communication port 26, and the rotating shaft 27 of the opening / closing valve 22 is held by the valve housing 23. The rotation shaft 27 has its axis aligned with the machining axis O of the drill, and one end 27a thereof is located inside the surge tank 4, while the other end 27b is extended outside the surge tank 4. An unillustrated link 28 for connecting an actuator is attached to the other end portion 27b.

The rotating shaft 27 is a locking member that is fitted to the one end 27a and the other end 27b of the rotating shaft 27 in the radial direction of the rotating shaft 27.
29 or 30 is installed. That is, one end 27
The first locking member 29 mounted on the a side will be described as an example. As shown in FIG. 8, a circular mounting groove 31 is formed in the one end 27a, so that both sides in the axial direction have a large diameter portion 27c. , 2
A small-diameter portion 27e formed as 7d is formed, and when the first locking member 29 is elastically pushed into the small-diameter portion 27e while expanding the cutout portion 29a, the diameter is again reduced. Will be completely fitted to the small diameter portion 27e. In such an attached state, the first locking member 29 has the rotating shaft 27
Since the protruding portion abuts the valve housing 23, the rotating shaft 27 is displaced relative to the valve housing 23 toward the other end 26b by a predetermined amount or more. Regulated. Of course, the second locking member 30 is also attached in the same manner as the first locking member 29.
Thus, the rotation shaft 27 is restricted from being displaced toward the one end portion 27a side of the valve housing 23 by a predetermined amount or more. The pivot shaft 27 is rotatably held with respect to the valve housing 23 in a state in which the displacement in the axial direction is restricted by the locking members 29 and 30. The numeral 32 in FIG. 3 is a washer.

With the attachment of the first locking member 29, this first
Along with the locking member 29, the rotary shaft 27 (one end portion 27a of the rotary shaft 27) slightly projects from the front end surface 23c of the valve housing 23. This projecting portion is located in the storage recess 33 that opens to the inner back surface 25b of the fitting recess 25. Then, the storage recess 33
When the valve housing 23 is fitted into the fitting concave portion 25, the opening portion of the fitting concave portion 25 is closed by (the tip surface 23c of) the valve housing 23. Therefore, even if the first locking member 29 is disengaged from the rotating shaft 27, the first locking member 29 remains in the storage recess 33,
It is reliably prevented from falling into the intake expansion chamber 6A or 6B.

As described above, the inner surface of the storage recess 33 forms the covering portion 33a surrounding the first locking member 29. However, in the embodiment, the covering portion 33a causes the first locking member 29 to rotate. It is designed to prevent itself from being disengaged from the drive shaft 27. That is, as shown in FIG. 6, the inner diameter of the covering portion 33a is slightly larger than the outer diameter of the first locking member 29 attached to the rotating shaft 27. The interval l2 is set to be significantly smaller than the depth 1 of the mounting groove 31 of the first locking member 29. This prevents the first locking member 29 from being displaced outwardly in the radial direction of the rotating shaft 27 by a predetermined amount or more even if it is subjected to vibration or the like. Detachment is reliably prevented.

Here, the on-off valve 23 is assembled to the valve housing 23 in advance by using both locking members 29 and 30, and then the valve housing 23 is fitted into the fitting recess 25 of the surge tank 4 to cause the surge. It is attached to the tank 4. At the time of completion of this assembly, the portion of the valve housing 23 located inside the surge tank 4 has the inner surface 25 of the fitting recess 25 as described above.
b, it fits snugly on the inner back surface 25b) and the rattling is surely prevented. In addition, since the valve housing 23 and the fitting recess 25 (the inner surface thereof) are in surface contact curved like a cylindrical surface or a conical surface, their sealing action, that is, both intake expansion chambers 6A and 6B. The effect of sealing and is also good.

Although the embodiment has been described above, depending on the engine specifications, the communication passage 5a formed in the partition wall 5 may be used as a communication passage that connects the intake expansion chambers 6A and 6B for obtaining the resonance effect in the low engine speed region. It can be eliminated and configured as a communication path passing through both branch pipes 11A and 11B. Of course, the valve housing 23 can be easily molded by molding plastic or light metal.

(Effects of the Invention) As is apparent from the above description, the present invention holds the on-off valve for switching the equivalent communication passage length of both intake expansion chambers defined in the surge tank by holding this on-off valve. It can be easily assembled in the surge tank by a fitting or insertion method using the valve housing that is provided.

Further, the valve housing can be automatically held in the surge tank without rattling just by fitting it in the fitting recess, and a seal between the fitting portions of the valve housing and the fitting recess can be provided. It can be good.

In addition, even if the valve housing is attached with being tilted (rotated) with respect to the normal state due to the mounting of the valve housing, the state of the surface contact between the valve housing and the fitting concave portion is made normal. Since it can be the same as in the case of the state, a seal can be obtained between the fitting portions of the valve housing and the fitting recess, and the sealing performance is always secured without depending on the sealing member.

Furthermore, since the fitting recess into which the valve housing is fitted is the conical inner back surface and the cylindrical inner surface, the machined surface for drilling can be used as it is and the fitting recess can be easily formed. Thus, the above sealing performance can be obtained very easily.

[Brief description of drawings]

FIG. 1 is a simplified plan view showing an embodiment of the present invention. FIG. 2 is a front sectional view of FIG. 1 viewed from a direction orthogonal to the engine output shaft. FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a perspective view of the valve housing. FIG. 5 is a sectional view taken along line VV in FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a sectional view taken along the line VII-VII in FIG. FIG. 8 is an exploded view showing a mounting manner of the rotating shaft and the locking member. 1: Engine 2A, 2B: Bank 3A: Cylinder (one cylinder group) 3B: Cylinder (other cylinder group) 4: Surge tank 5: Bulkhead 5a: Communication passage 6A: 1st intake expansion chamber 6B: 2nd intake expansion Chamber 21: Communication port 22: Open / close valve 23: Valve housing 23b: Outer surface 23c: Inner end surface 24: Mounting hole 25: Fitting recess 25a: Inner side surface 25b: Inner back surface 26: Communication opening 27: Rotating shaft

Claims (1)

[Scope of utility model registration request] 1. A surge tank has a second partition connected by a partition wall to a first intake expansion chamber connected to one cylinder group having a non-continuous ignition sequence and to another cylinder group having a non-continuous ignition sequence to each other.
An intake system for an engine, which is defined as an intake expansion chamber, and in which an opening / closing valve for connecting and disconnecting the intake expansion chambers to switch the equivalent communication passage length is provided in the surge tank, Inside the surge tank, a fitting recess is formed along the partition wall from the outside of the surge tank, into which a valve housing that rotatably holds the on-off valve is fitted, and the fitting recess is a drill blade edge angle. And a conical inner surface having a conical shape with a conical shape, and a cylindrical inner surface that is continuous with the inner rear surface and has substantially the same diameter as the drill diameter. The inner end surface and the outer surface of the valve housing are shaped so as to match the shapes of the inner back surface and the inner side surface of the fitting recess, and the inner end surface of the valve housing is seated on the inner back surface of the fitting recess. The thickness of the partition wall fits the valve housing The intake device for an engine, wherein the thickness of the valve housing is equal to or larger than the thickness of the valve housing.