JPH0528337Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an improvement of an engine intake device that utilizes the dynamic effect of intake air to increase charging efficiency.

(Prior Art) There is a method disclosed in Japanese Patent Application Laid-Open No. 115818/1983 to improve the charging efficiency by utilizing the dynamic effect of intake air, especially resonance supercharging. That is, the inside of the surge tank is divided into two intake expansion chambers, a first and a second intake expansion chamber, by a partition wall, and one cylinder group whose ignition order is not consecutive to each other is placed in the first intake expansion chamber, and the cylinder group whose ignition order is not consecutive to each other is divided into two intake expansion chambers. The other cylinder groups are communicated with the second intake expansion chamber. In order to obtain resonance supercharging over a wide operating range of the engine, that is, to adjust the tuning conditions of the intake system for resonance supercharging in response to changes in engine operating conditions, a surge tank was installed inside the surge tank. Communication between the two intake expansion chambers through the on-off valve,
It is designed to be blocked. More specifically, for example, in a low engine speed range, the on-off valve is closed (cut off), and both intake expansion chambers are connected to each other through a long path such as a confluence section formed in the common intake pipe upstream of the surge tank. In other words, the on-off valve is used to switch the equivalent communication path length between the two intake expansion chambers so that they communicate with each other through an extremely short path by opening (communication) the on-off valve. It's like this.

(Problem to be solved by the invention) By the way, since the on-off valve disposed inside the surge tank is opened and closed by an actuator installed outside the surge tank, one end of its rotating shaft is It will be located within the surge tank, and the other end will extend outside the surge tank for connection to the actuator.

Further, the on-off valve, that is, its rotation shaft is held in a valve housing that is formed integrally with the surge tank or separately, and it is necessary to restrict axial displacement of this valve housing. To regulate this axial displacement, a locking member that is fitted to the rotating shaft from the radial direction, such as a snap spring (also called a C-ring), is commonly used from the viewpoint of ease of installation. It is conceivable to do so. That is, a first locking member is fitted from the radial direction onto one end of the rotation shaft located inside the surge tank, and the first locking member locks the rotation shaft in the axial direction toward the outside of the surge tank. While regulating the displacement, by fitting the second locking member from the radial direction to the other end of the rotating shaft extending outside the surge tank, the axial displacement of the rotating shaft toward the inside of the surge tank is prevented. It is conceivable to regulate it.

However, although the locking member that is fitted from the radial direction is easy to install, it is relatively easy to come off, so the first locking member located inside the surge tank comes off and enters the engine cylinder together with the intake air. It is also possible that they may be sucked in, and the problem is how to prevent such a situation.

Therefore, an object of the present invention is to utilize a locking member fitted from the radial direction of the rotating shaft to restrict the axial displacement of the rotating shaft of the on-off valve located in the surge tank. An object of the present invention is to provide an intake device for an engine that can reliably prevent a locking member located in a surge tank from coming off a rotation axis when the surge tank is operated.

(Means and effects for solving the problems) In order to achieve the above-mentioned object, the present invention has the following configuration. That is, the inside of the surge tank is divided by a partition wall into a first intake expansion chamber connected to one cylinder group whose firing order is not consecutive to each other and a second intake expansion chamber connected to another cylinder group whose firing order is not consecutive to each other. , an engine intake system in which an on-off valve is disposed in the surge tank for communicating and cutting off the two intake expansion chambers and switching the equivalent communication path length, the on-off valve being held in a valve housing; A rotating shaft of the valve has one end located within the surge tank and the other end extending outside the surge tank, and the rotating shaft is fitted in the one end from a radial direction. The first locking member and the second locking member fitted in the other end from the radial direction restrict axial displacement with respect to the valve housing, and the valve housing has the first locking member. The first locking member is configured to include a cylindrical envelope portion that circumferentially surrounds the member and restricts the first locking member from coming off radially outward.

With such a configuration, the first and second
The displacement of the rotating shaft in the axial direction can be controlled very easily by using both of the locking members, and the first locking member located inside the surge tank can be controlled by the envelope provided in the valve housing. It can reliably prevent it from coming off the rotation axis.

In addition, when attaching the first locking member to the rotation shaft, before installing the second locking member, one end side to which the first locking member is attached protrudes outward to a greater extent than the envelope portion of the valve housing. After installing the first locking member, the second locking member can be installed by displacing the rotation shaft toward the other end. .

(Example) An example of the present invention will be described below based on the attached drawings.

In Figures 1 and 2, the engine 1, which is an OHC type V-6 cylinder, has two banks 2 on the left and right.
A, 2B, and the left bank 2A has odd-numbered cylinders 3, No. 1, No. 3, and No. 5, sequentially from one end side in the engine output shaft direction (lower end side in Figure 1) to the other end side.
Similarly, bank 2B on the right side has 2
Even-numbered cylinders 3B, such as No. 3, No. 4, and No. 6, are configured. And these six cylinders 3A, 3B
For example, the firing order is 1st, 2nd, 3rd, 6th, etc.
5 and 4, and the odd-numbered cylinders 3A of bank 2 on the left constitute one cylinder group whose ignition order is not consecutive to each other, and the even-numbered cylinders 3B of bank 3 on the right mutually ignite. They constitute another cylinder group that is not consecutive in order.

A surge tank 4 is disposed above the V-bank central space X formed between the left and right banks 2A and 2B. This surge tank 4 extends in the front-rear direction, that is, in the direction of the engine output shaft, and has a partition wall 5 inside that extends in the direction of the engine output shaft.
As a result, a first intake expansion chamber 6A and a second intake expansion chamber 6B are defined. Three intake/exhaust ports 7A or 7B are formed in each of the left and right side walls of the surge tank 4, and the intake/exhaust ports 7A opening into the first intake expansion chamber 6A are connected to each other via independent intake pipes 8A. , is connected to the intake port 9A of the cylinder 3A in the left bank 2A. Also,
Intake exhaust port 7B that opens into the second intake expansion chamber 6B
are respectively connected to the intake port 9B of the cylinder 3B in the right bank 2B via an independent intake pipe 8B. In this way, the intake expansion chambers 6A, 6B
are said to be for bank 2A or 2B on the far side, respectively, but for this reason independent intake pipe 8
A and 8B are designed to be as long as possible so that they extend away from the left and right side walls of the surge tank 4 and then are folded back approximately 180 degrees so as to pass below the surge tank 4 and connect to the intake port 9A or 9B. is formed, so that so-called inertial supercharging is obtained.

Further, on the rear wall of the surge tank 4, there is one first intake inlet 10A that opens into the first intake expansion chamber 6A.
is formed, and one second intake inlet 10B that opens into the second intake expansion chamber 6B is formed. Then, the downstream portion of one common intake pipe 11 is branched into two branch pipes 11A and 11B, a first branch pipe 11A and a second branch pipe 11B.
A, and the second branch pipe 11B is connected to the second intake inlet 11B. As a result, the intake air from the common intake pipe 11 is branched from the branching part (merging part) Y to the branching pipes 11A and 11B, so that the intake air is divided and introduced into both the intake expansion chambers 6A and 6B. Each cylinder 3A in the left bank 2A is supplied from the first intake expansion chamber 6A, and each cylinder 3A in the right bank 2B is supplied from the second intake expansion chamber 6B.
B is supplied.

In addition, 12A and 12B in Fig. 1 are exhaust ports,
In FIG. 2, 13A and 13B are fuel injection valves.

A communication pipe 21 is disposed within the surge tank 4 in close proximity to its front wall. This communication pipe 21 passes through the partition wall 5 that defines both the intake expansion chambers 6A and 6B, and communicates the two intake expansion chambers 6A and 6B over a short distance. It is opened and closed by an on-off valve 22 disposed within the first intake expansion chamber 6A.

With the above configuration, when the on-off valve 22 is closed, both the intake expansion chambers 6A and 6B communicate with each other at the branch part Y of the common intake pipe 11, that is, both the branch pipes 1
1A and 11B through a long path, and the synchronization condition for resonance supercharging is satisfied in the low engine speed range. In addition, the on-off valve 22
When opened, both intake expansion chambers 6A and 6B are communicated with each other by a short path via the communication pipe 21, and the synchronization condition for resonance supercharging is satisfied in the high engine speed range (because of resonance supercharging, both intake expansion chambers 6A and 6B are Intake expansion chambers 6A and 6
The length of the communication path communicating with B, that is, the equivalent communication path length depends on the shorter communication path).

As shown in FIG. 3, the on-off valve 22 is supported by a valve housing 23 so as to be rotatable but not displaceable in the axial direction. The valve housing 23 is assembled to the surge tank 4 through a narrow mounting hole 24 formed in the front wall of the surge tank 4 so that the on-off valve 22 is located at one end opening of the communication pipe 21. In this assembled state, the flange portion 23a integrally formed on the valve housing 23 is fixed to the surge tank 4 with bolts or the like (not shown).

One side of the valve housing 23 contacts one end surface of the communication pipe 21 during assembly, and has a communication port 25 that is connected to the communication pipe 21 in this state. An on-off valve 22 is provided in this communication port 25.
is located, and a rotation shaft 26 of this on-off valve 22 is held by a valve housing 23. This rotating shaft 26 has one end 26a connected to the surge tank 4.
The other end 26b extends outside the surge tank 4, and a link 27 for connecting an actuator (not shown) is attached to the other end 26b. There is.

A locking member 28 or 29 is attached to one end 26a and the other end 26b of the rotating shaft 26, respectively, which are fitted from the radial direction of the rotating shaft 26. That is, taking the first locking member 28 attached to the one end 26a as an example, as shown in FIG. Small diameter portion 26e with large diameter portions 26c and 26d
is formed, and when the first locking member 28 is pushed into the small diameter portion 26e from this radial direction while expanding its notch 28a using its elasticity, the diameter will eventually contract again and the cutout portion 28a will expand. It will be completely mated. In such an attached state, the first locking member 28 projects slightly outward in the radial direction of the rotation shaft 26, so that this projecting portion touches the valve housing 23.
By coming into contact with this, the rotation shaft 26 is prevented from being displaced more than a predetermined amount toward the other end 26b with respect to the valve housing 23. Of course, the second locking member 29 is also attached in the same manner as the first locking member 28, and the second locking member 29 allows the rotation shaft 26 to be
is restricted from displacing more than a predetermined amount toward the one end 26a side with respect to the valve housing 23. With both of these locking members 28 and 29, the rotation shaft 26 is
It is rotatably held relative to the valve housing 23 in a state where displacement in the axial direction is restricted. In addition, 31 in FIG. 3 is a washer.

Here, the valve housing 23 has a
As shown in the figure, a cylindrical covering portion 23b that surrounds the first locking member 28 in its entire circumferential direction is integrally molded. The inner diameter of this covering portion 23b is slightly larger than the outer diameter of the first locking member 28 attached to the rotating shaft 26, but both 28 and 2
3b (inner surface) is set to be significantly smaller than the depth l1 of the mounting groove 30 of the first locking member 28. As a result, the first locking member 28
Even if subjected to vibration etc., the covering portion 23b prevents the rotating shaft 26 from being displaced radially outward beyond a predetermined value, that is, it is reliably prevented from coming off from the rotating shaft 26. .

The rotation shaft 26 to which the above-mentioned locking members 28 and 29 are attached may be assembled to the valve housing 23 in the following manner. That is, with the valve housing 23 removed from the surge tank 4,
The rotation shaft 26 is inserted into the shaft hole 23c of the valve housing 23, and one end portion 26a thereof is made to protrude more than the envelope portion 23b. In this state, the first locking member 28 is attached to one end 26a of the rotating shaft 26 without being obstructed by the cover 23b, and then the first locking member 28
8 is located within the envelope portion 23b.
is axially displaced toward the other end 26b, and the second locking member 29 is attached to the other end 26b. Then, after mounting the on-off valve 22 to the rotating shaft 26 (its mounting screw is indicated by reference numeral 32 in FIG. 3), the valve housing 23 may be assembled into the surge tank 4.

Although the embodiments have been described above, the valve housing 23 may be formed integrally with the surge tank 4, and the valve housing 23 may be formed integrally with the surge tank 4, and there may be a communication connection between the two intake expansion chambers 6A and 6B in the partition wall 5 without using the communication pipe 21 separately. The mouth may be opened directly. Of course, the valve housing 23 can be easily formed integrally with the envelope 23b from a suitable material such as plastic or metal.

(Effects of the invention) As is clear from the above, the invention has the following effects:
Since the axial positioning of the opening/closing valve rotation shaft with respect to the valve housing is performed using locking members fitted to the rotation shaft from the radial direction, this axial positioning can be easily performed. can.

In addition, the locking member located inside the surge tank is reliably prevented from falling off by the covering part provided on the valve housing, so the locking member located inside the surge tank can be prevented from falling off. You can definitely avoid situations such as being loaded and being sucked into the engine. Of course, since the covering portion need only have a shape that surrounds the locking member in its circumferential direction, the structure for preventing the locking member from falling off becomes extremely simple.

[Brief explanation 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 perpendicular to the engine output shaft. FIG. 3 is a sectional view taken along the line of FIG. 1. FIG. 4 is a view of the valve housing as viewed from the side of its envelope. FIG. 5 is an exploded view showing in detail the attachment portion of the locking member to the rotation shaft. 1...Engine, 2A, 2B...Bank, 3A
... Cylinder (first cylinder group), 3B... Cylinder (other cylinder group), 4... Surge tank, 5... Bulkhead, 6A
...First intake expansion chamber, 6B...Second intake expansion chamber,
21...Communication pipe, 22...Opening/closing valve, 23...
Valve housing, 23b...enveloping part, 23c...shaft hole, 25...communication port, 26...rotation shaft, 26a...
...One end, 26b...Other end, 28...First locking member, 28a...Notch, 29...Second locking member, 30...Mounting groove.

Claims (1)

[Scope of Claim for Utility Model Registration] Inside the surge tank, a first intake expansion chamber is connected to one cylinder group whose ignition order is not consecutive to each other, and a second intake expansion chamber is connected to another cylinder group whose ignition order is not consecutive to each other. An intake system for an engine, wherein an on-off valve is provided in the surge tank for communicating and cutting off the two intake expansion chambers to switch an equivalent communication path length, the valve housing comprising: a valve housing; A rotating shaft of the on-off valve held in the opening/closing valve has one end located within the surge tank and the other end extending outside the surge tank, and the rotating shaft has a diameter at the one end. A first locking member fitted from the radial direction and a second locking member fitted from the radial direction at the other end restrict axial displacement with respect to the valve housing, and the valve housing includes: , a cylindrical envelope portion that circumferentially surrounds the first locking member and restricts the first locking member from coming off radially outward. Intake device.