JP2017053314A - Intake gas negative pressure generating device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake gas negative pressure generating device capable of attaining more compact in size and high performance formation while employing means for performing a direct restriction of turning position of a valve body 3 as means for restricting turning motion of a throttle valve 4.SOLUTION: This invention enables a basic configuration to be applied to its small-sized compact*high accuracy characteristics by providing only one button [button]-like stopper 21 for restricting only a full-closed position of a valve body 3 as a stopper mechanism 20 and by setting a protrusion and arranging position of the stopper 21 at a location where only extremity end portion 32 of the valve body 3 is received and it is positioned at a downstream side of the valve body 3 while keeping the minimum number of stoppers and protrusion volume. Further, it is possible to attain a positive abutment between the valve body 3 and the stopper 21 by forming a receiving surface 22a receiving the down-stream side end surface 3b of the valve body 3 at a salient curved surface 23 at the stopper 21 even if a convenient and simple design*manufacturing method is applied and it is also possible to attain more an effect of high accuracy formation for restriction against turning position of the valve body 3.SELECTED DRAWING: Figure 3

Description

  The present invention is incorporated in an intake device of an internal combustion engine (hereinafter referred to as an engine), and generates intake negative pressure on the downstream side (engine intake side) by opening and closing a valve that controls the amount of intake air. It relates to a generator.

[Conventional technology]
The intake negative pressure generator is used to control the intake air amount by opening and closing a valve (throttle valve) disposed in the intake system passage of the engine, and is also referred to as a “throttle device”. As this type of device, devices having various configurations have been put to practical use. A typical example of such a device is a throttle device as described in Patent Document 1.

  Such a throttle device has a throttle valve (specifically, a butterfly plate valve) that opens and closes an air flow path in a throttle housing (hereinafter also referred to as a valve housing) that forms part of an intake pipe. ) And the throttle valve is rotated according to the operating state of the engine to control the amount of intake air to the engine. And, in order to uniquely determine the opening degree of the throttle valve (the flow passage area of the air flow path) to the fully open state or the fully closed state, a restricting means for restricting the rotational position of the valve body of the throttle valve (hereinafter referred to as the throttle valve opening) , Also referred to as a stopper mechanism).

By the way, until now, this restricting means uses the rotational position of the valve body of the throttle valve (hereinafter simply abbreviated as a valve body) as the rotational position of the rotation shaft of the throttle valve (hereinafter simply abbreviated as the shaft). From the standpoint of indirectly regulating the shaft, in order to uniquely determine the rotational position of the shaft inside the drive device side that rotates the shaft, for example, in the speed reducer or spring device (opener mechanism including a return spring) It was customary to incorporate a stopper mechanism.
However, in recent years, in response to various demands such as improvement of matching accuracy between the throttle valve side and the drive device side, downsizing of the drive device side, etc. with the downsizing and high performance of the throttle device, the indirect regulation means described above Instead, a direct restricting means in which a stopper mechanism for directly restricting the rotational position of the valve body is disposed on the inner wall of the air flow path of the throttle housing is employed, and a stopper having a specific structure as disclosed in Patent Document 1 above. Mechanisms are also useful.

[Problems of the prior art]
However, since the direct regulating means has a basic configuration in which the stopper portion protrudes (projects) from the inner wall surface of the throttle housing into the air flow path, the stopper portion itself has a resistance that reduces the effective flow path area to some extent. The most difficult point is that the members are configured, and this is a barrier to further miniaturization and higher performance of the entire throttle device.
In Patent Document 1, specific stopper mechanisms as direct restricting means are introduced in various forms. However, in these specific structures, all of the apparatus is further reduced in size and performance. However, it is still inadequate for further improvement, and further improvement is desired.

Therefore, the present inventor has conducted a number of experiments and researches in order to search for the improvement measures, and this time, it has come to ascertain that the following study issues are inherent in the direct regulation means. It was.
(1) Which rotation position should be regulated with respect to the throttle valve?
-When directly restricting the rotation position of the throttle valve at the valve body, which rotation position should be preferentially controlled (the number of stopper parts protruding in the air passage and the size of the stopper parts themselves <projection volume) Is there any way to minimize>?)?
(2) How should the positional relationship between the valve body and stopper mechanism be selected?
-There are upstream and downstream valve bodies. Further, the valve body is a plate type butterfly type that rotates around the shaft. What kind of positional relationship to restrict such a valve body is most effective.
・ Can you pursue more of what the stopper mechanism should be?
-It is desirable that the stopper mechanism is originally "a small mechanism that can regulate the rotational position of the valve body with high precision". As a measure to meet such demands, the stopper mechanism itself may be further examined in terms of structure.

JP 2004-293451 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to achieve further miniaturization and higher performance while adopting means for directly regulating the rotational position of the valve body. It is an object of the present invention to provide an intake negative pressure generator that can be used as an engine, and in particular, an intake negative pressure generator for an engine suitable as a throttle device.

[Means of Claim 1]
The invention according to claim 1 (intake negative pressure generator for an engine) has an air flow path having one end connected to the air intake side, which is upstream, and the other end connected to the intake side of the engine, which is downstream. The valve housing has a plate-shaped valve body that is accommodated in the air flow path, and the valve body opens and closes while rotating about an axis orthogonal to the air flow path. And a stopper mechanism that directly regulates the rotational position of the valve by the rotational position of the valve body, and the valve closes the air flow path so that the valve is positioned downstream of the air flow path. The basic configuration is to generate intake negative pressure.

The device according to the present invention includes, as the stopper mechanism described above, a single button (button) type stopper protruding from the inner wall surface forming the air flow path of the valve housing into the air flow path. It has two feature points.

(1) This stopper has a button (button) shape in which the shape of the stopper itself is a locally protruding form.
(2) This stopper restricts only the fully closed position of the valve body.
(3) The protruding position of the stopper is a region where the length from the rotation fulcrum orthogonal to the axis on the rotation trajectory of the valve body is the longest (a place where only the tip portion of the valve body is received), and The point is set to be located downstream of the valve body.
(4) The stopper is provided with a receiving surface having a convex curved surface at the receiving portion facing the downstream end surface of the valve body, and the downstream end surface of the valve body abuts on the convex curved surface of the receiving portion. The point that regulates the fully closed position of the disc.

According to the said structure, there exist the following effects for every feature point.
First, by the feature points (1) and (2), it is possible to efficiently achieve the restriction of the rotational position of the valve with the minimum number of stoppers as one stopper and the minimum stopper protrusion volume in which the protrusion form is a button. Can do.

  In addition, the feature point (3) absorbs dimensional tolerances and manufacturing errors of the valve body and stopper to improve the accuracy of the fully closed position of the valve body and reduce the return spring load to reduce the size of the spring device. It can be done at the same time.

  Further, the feature point (4) allows the valve body and the stopper to be brought into contact with each other accurately even if a simple design / manufacturing method is adopted, and further improves the accuracy of the fully closed position of the valve body. Can be encouraged.

  Therefore, in the present invention, an intake negative pressure generator for an engine suitable as a throttle device that can achieve further downsizing and high performance while directly adopting a restricting means as a means for restricting the rotational position of the valve. Can be provided.

As a typical application example of the device of the present invention, it is provided for explanation of the overall configuration of the throttle device, and is a schematic cross-sectional view of the device (Example 1). FIG. 1 is a schematic longitudinal sectional view of the air flow path portion in the throttle housing (II-II sectional view in FIG. 1) for both the explanation of the main part of the throttle device and the explanation of the first embodiment of the device of the present invention. (Example 1). 2A and 2B are schematic longitudinal sectional views of an air flow path portion in a throttle housing (Example 1). FIGS. 2A and 2B are views similar to FIG. 2, in which FIG. 3A is a view as viewed in FIG. 3B, and FIG. Example 1). As another embodiment of the device of the present invention, a modified example of the contact relationship between the throttle valve and the stopper mechanism will be described, and (a) and (b) are enlarged longitudinal sectional views of main parts showing different contact relationships. (C) is a B view of the contact relationship shown in (b) (Example 2). FIG. 9 is a view for explaining a modified example of a stopper mechanism as another embodiment of the device of the present invention, in which (a) is an enlarged longitudinal sectional view of a main part, and (b) is a C view in (a) (Example 3) ). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic enlarged view showing a relationship between a throttle valve and a stopper mechanism (prior art) for explaining the problem of the device of the present invention.

  Hereinafter, the best mode for carrying out the present invention will be described in detail according to embodiments shown in the drawings. In the drawings, the same reference numerals in the drawings indicate the same or equivalent parts, and redundant description is omitted in principle.

[Example 1]
In this embodiment, as a typical application example of the device of the present invention, a throttle device mounted on an automobile engine is particularly illustrated. In the following description, first, the overall configuration of the throttle device and the positioning of the restricting means (stopper mechanism) are outlined, and then the basic structure of the stopper mechanism that constitutes the restricting means and the characteristic functions of each embodiment are sequentially described. .

[Basic configuration of throttle device]
First, a basic configuration (overall configuration) of the throttle device will be outlined based on FIGS. 1 and 2.

The throttle device 100 includes a throttle housing 1, a throttle valve 4 having a shaft 2 and a valve body 3, a DC motor 5, a speed reducer 6, and a spring device 7 as main components.

The throttle housing 1 forms a valve housing, is made of a molded product made of a well-known heat-resistant material such as aluminum alloy or synthetic resin, and has an air flow path 10 and a recess 11.
The air channel 10 is formed as a circular channel having a circular cross section that penetrates the throttle housing 1 in the axial direction, and one end 10a is connected to an upstream side air intake side (for example, an air cleaner C), and the other end 10b is connected to the intake side (for example, intake manifold M) of the engine which is the downstream side. The air flow path 10 houses a throttle valve 4 for opening and closing the air flow path 10.
The recess 11 is provided in the throttle housing 1 so that the side surface is open, and houses functional parts such as the DC motor 5, the reduction gear 6, and the spring device 7. The recess 11 is fitted with a synthetic resin cover 12 that closes the opening end and embeds wiring and the like for electrically connecting the functional component and the external device.

The throttle valve 4 is configured by appropriately attaching and fixing a shaft 2 that forms a rotating shaft and a valve body 3 that opens and closes the air flow path 10 by fixing means such as screws.
The shaft 2 is disposed so as to be orthogonal to the throttle housing 1 across the air flow path 10 and is rotatably supported.
The valve body 3 has a disk shape that matches the cross-sectional shape of the air flow path 10.
Therefore, the throttle valve 4 as a whole is disposed so as to be orthogonal to the throttle housing 1 across the air flow path 10, and the valve body 3 rotates around the axis of the shaft 2. It is a so-called butterfly valve that moves.
Thus, by opening and closing the air flow path 10 by the throttle valve 4, the flow area of the air flow path 10 is changed (the intake negative pressure generated downstream of the throttle valve 4 is changed), and the air flow from the air cleaner A is changed. The intake air amount (intake air amount) sucked into the intake manifold M of the engine via the path 10 is adjusted (controlled).

The direct current motor 5 serves as a drive source for turning the throttle valve 4 and controls the throttle valve 4 with a predetermined speed via a speed reduction device 6 and a spring device 7 based on a command signal from an engine control means (not shown). Drive to the pivot position.
The spring device 7 is represented by an opener mechanism, and includes a return spring 8 that returns the rotational position of the throttle valve 4 to the initial position.

Thus, the throttle device 100 configured as described above operates as follows.
First, when the engine is not operating or in an idling state, the throttle valve 4 (valve element 3) is brought into the initial position state indicated by the solid line in FIG. 2 by the action of the return spring 8 included in the spring device 7. Yes, the air flow path 10 is closed.
The rotational position of the throttle valve 4 (the initial position of the solid line) is the minimum area that can secure the minimum intake air amount QMIN (including QMIN = 0) as the intake air amount to the engine with the effective flow passage area of the air passage 10 as the intake air amount. It corresponds to the position to perform and is the “fully closed position”. On the other hand, the throttle valve 4 indicated by a two-dot chain line in FIG. 2 is a rotation position at which the effective flow path area of the air flow path 10 is set to the maximum area that can secure the maximum intake air amount QMAX as the intake air amount to the engine. Is the “fully open position”.
When the engine enters an operating state, the DC motor 5 is started based on a command signal from an engine control means (not shown). The direct current motor 5 rotates the throttle valve 4 via the speed reducer 6 and the spring device 7 within the rotation trajectory range (shown by the broken line arrow) from the “fully closed position” to the “fully open position”. Thus, since the throttle valve 4 determines the opening degree (effective flow path area) of the air flow path 10 each time, the required intake air amount corresponding to the operating state is supplied to the engine.

[Positioning of restriction means (stopper mechanism)]
By the way, in order to uniquely determine the minimum intake amount QMIN and the maximum intake amount QMAX to the engine, the regulation for defining the “fully closed position” and the “fully opened position” as the rotational position of the throttle valve 4 is described. Requires means.
In this restricting means, instead of the indirect restricting means in which the stopper mechanism is incorporated in the conventional speed reduction device 6 or the spring device 7, a stopper mechanism is provided in the air flow path 10 of the throttle housing 1, thereby providing a valve body. The direct regulating means of directly regulating the rotational position 3 has come to be adopted.

[Background of Example 1]
However, since the direct restricting means has a basic configuration in which the stopper mechanism 20 protrudes from the inner wall surface 13 of the throttle housing 1 into the air flow path 10 as shown in FIG. It is a common problem for those skilled in the art how to cover the above-mentioned drawbacks.

The present inventor has examined the above problems from the following viewpoints and has considered a solution for each item to be examined, and will be described in detail with reference to FIGS.

Examination item 1 …… “Which position should be preferentially regulated with respect to the throttle valve 4 in the stopper mechanism 20”? In the throttle device 100, the throttle valve 4 that determines the minimum intake amount QMIN to the engine The fully closed position (solid line position) is more important than the fully open position (two-dot chain line position) that determines the maximum intake air amount QMAX. This is due to the fact that the minimum intake amount QMIN required by the engine is set delicately, but depends on the fact that the throttle valve 4 is a butterfly type. That is, in the case of the butterfly type, in the vicinity of the fully closed position of the valve body 3, the effective flow area of the air flow path 10 is greatly changed by slightly shifting the rotational position of the valve body 3, and the minimum intake amount QMIN is reduced. Since the fluctuation range becomes large, highly accurate position regulation is required for the fully closed position.
Therefore, it is expected that the direct regulating means can contribute to minimizing the number of stoppers of the stopper mechanism 20 and minimizing the stopper protruding volume by constructing as the stopper mechanism 20 that regulates only the fully closed position of the throttle valve 4. .

Examination item 2 ...... “Which stopper mechanism 20 should be arranged on the upstream side or the downstream side with respect to the throttle valve 4”? When examining only which end face of the upstream end face 3a or the downstream end face 3b should be received? As described above, when restricting only the fully closed position of the throttle valve 4, as described above, It is advantageous to receive the downstream end face 3b.
As shown in FIG. 2, the throttle valve 4 is generated upstream of the throttle valve 4 when the valve body 3 is displaced to the solid line position by the return spring 8 of the spring device 7, that is, in the fully closed position. A load due to the differential pressure P between the intake pressure and the intake pressure generated on the downstream side is applied to the upstream end surface 3a of the valve body 3 in the valve closing direction as indicated by an arrow.
Therefore, by effectively using this differential pressure P as the restoring force of the throttle valve 4, the throttle valve 4 can be firmly pressed against the stopper mechanism 20 with a small return spring load. Therefore, it can be expected that the return spring 8 (spring device 7) contributes to downsizing.

-Examination item 3 ...... "Whether the stopper mechanism 20 should be arranged to receive the throttle valve 4 at its downstream end face 3b even if it is received at the downstream end face 3b"-the downstream end face of the throttle valve 4 Even if it is advantageous to receive at 3b as described above, a further advantage is an examination from the viewpoint of “which part of the downstream end surface 3b should be received?”. According to such examination results, it is more effective to receive the valve body 3 at a position (tip portion) farthest from the shaft 2.
That is, as apparent from FIG. 3A, in the butterfly valve body 3, even if the root portion 31 close to the shaft 2 and the distal end portion 32 have the same rotation angle θ, they are substantially There is a peculiar relationship in which the length of the circular trajectory, that is, the arc length X required for the rotation is larger in the latter than in the former.
Therefore, if the butterfly type characteristic is effectively utilized and the rotational position of the valve body 3 is directly restricted by the tip portion 32 far from the shaft 2, the valve body is equivalent to the difference in the arc length X. 3 and the stopper mechanism 20 can be relaxed. This means that the dimensional tolerance of the valve body 3 and the stopper mechanism 20 and the range in which manufacturing errors can be absorbed can be expanded, and the fully closed position accuracy with respect to the throttle valve 4 can be improved.

Thus, to summarize the examination results in the examination items 2 and 3 described above, the protruding position of the stopper mechanism 20 is the downstream side of the valve body 3 and the position where only the tip portion 32 of the valve body 3 is received. It is determined that it is optimal to set to.

-Consideration item 4 ...... About the “appropriate shape of the stopper mechanism 20 itself” —The stopper mechanism 20 itself is essentially a “small and highly precise mechanism that can regulate the rotational position”, but “miniaturization” From the standpoint of how the receiving area of the throttle valve 4 can be reduced, “high accuracy” is arranged from the standpoint of how accurate positioning can be performed, and in consideration of manufacturing aspects, it is multifaceted. After examination, the following insights were obtained.

(1) First, if the receiving area of the throttle valve 4 is increased, for example, “the contact area with the valve body 3 can be increased, and the rotational position of the throttle valve 4 can be regulated with high accuracy”. Traditional ideas are not always realistic.
That is, it was possible to confirm the following event that the positioning accuracy is impaired when the receiving area, that is, the stopper mechanism 20 is increased.
According to the inventor's verification, the butterfly valve body 3 is inclined even in the fully closed position, and the receiving surface of the stopper mechanism 20 is also provided in an arc shape along the inner peripheral surface of the air flow path 10. In addition, it is considerably difficult to bring the inclined surface and the arc surface into contact with each other even if the dimensional tolerance is set strict, and if the manufacturing error is taken into consideration, the valve body 3 and the stopper mechanism 20 are more difficult. It turned out that it can contact only in a specific local location.
(2) Secondly, as shown in FIG. 7, the stopper side end surface 3 </ b> A of the valve body 3 collides with the edge portion 20 </ b> A of the stopper mechanism 20 to cause damage to both in relation to the above contact problem. And the like, and the rotation position restriction function and the flow rate control function are hindered.
In particular, as described above, since the contact position between the valve body 3 and the stopper mechanism 20 is not uniquely determined, the damaged portion cannot be predicted pinpoint, and cannot be reflected in the design / manufacturing aspect. This is a fatal problem against "high accuracy".
(3) Therefore, considering these various points comprehensively, the shape and structure of the stopper mechanism 20 itself that truly contributes to “miniaturization” and “higher accuracy” are desired.

[Features of Example 1]
In the present embodiment, the solution for each examination item described above is incorporated as a feature point as follows.
Hereinafter, characteristic points in the throttle device 100 of the present embodiment will be sequentially described with reference to FIGS.

(1) Feature point for study item 1 (first feature point)
As shown in FIG. 3 and FIG. 4A, the stopper mechanism 20 that directly constitutes the restricting means includes a button (button) type stopper 21 as the only stopper that restricts only the fully closed position of the throttle valve 4. .
It is noted that the only stopper 21 has a button (button) shape in which the shape of the stopper itself is a local protruding form (a form having a small protruding volume). That is, the “button shape” is not a belt-like shape extending in the circumferential direction but extending in the circumferential direction although it protrudes from the inner wall surface 13 forming the air passage 10 of the throttle housing 1 into the air flow path 10. A general term for a form that bulges locally with a short length and a small protruding volume. In this embodiment, as an example, rectangular buttons (buttons) having substantially the same circumferential length S and axial length J are selected as shown in FIG.
And this stopper 21 protrudes in the downstream of the throttle valve 4 in the air flow path 10, and by directly receiving the fully closed end face (downstream end face 3b) of the valve body 3, only the fully closed position of the throttle valve 4 is obtained. Is regulated.

According to the above configuration, the stopper portion protruding into the air flow path 10 is the only button-type stopper 21 having a small protruding volume, so that the rotational position of the throttle valve 4 is restricted to a minimum of one stopper 21. The number of stoppers and the minimum stopper protrusion volume whose protrusion form is a button shape can be efficiently achieved.
Therefore, the stopper mechanism 20 as the direct regulating means can be constructed with a basic structure that can suppress the influence of the flow path resistance on the air flow path 10 to the maximum extent.

(2) Feature points for study items 2 and 3 (second feature points)

(2-1) As described above in the first feature point (1), the only stopper 21 is projected on the downstream side of the throttle valve 4 so as to directly receive the downstream end face 3b of the valve body 3. I have to.
According to the above configuration, as shown in FIG. 2, the differential pressure P applied to the upstream end face 3a of the valve body 3 is effectively utilized as the restoring force of the throttle valve 4, and the throttle valve 4 is operated with a small return spring load. The stopper 21 can be pressed firmly. For this reason, it is possible to reduce the size of the return spring 8, and thus the spring device 7.

(2-2) The protruding position of the stopper 21 is set to a location that receives only the tip portion 32 of the valve body 3 with respect to the valve body 3.
Specifically, as shown in FIG. 3 (b), when the length from the rotation fulcrum O of the line orthogonal to the axis (shaft 2) on the rotation trajectory (indicated by the broken line arrow) of the valve element 3 is referred to as L. The “region” in which the length L is the longest is set as the location. Here, the “region” is not limited to the pin point at which the L length becomes the maximum value, but is a generic name of the portion as close to the tip as possible.
According to the above configuration, the fully closed position accuracy with respect to the throttle valve 4 can be improved by effectively utilizing the characteristics of the butterfly valve.
That is, as shown in FIG. 3A, in the butterfly type valve element 3, even if the rotation angle θ is the same, the fundamental portion 31 close to the shaft 2 and the far end portion 32 are substantially different. The rotational trajectory length, that is, the arc length X required for the rotation has a unique relationship in which the latter is larger than the former. By effectively utilizing this characteristic, the rotational position of the valve body 3 is directly restricted by the tip portion 32 far from the shaft 2, so that the valve body 3 and the stopper mechanism 20 are equivalent to the difference in the arc length X. It is possible to relax the accuracy of the contact position. This means that the dimensional tolerance of the valve body 3 and the stopper mechanism 20 and the range in which manufacturing errors can be absorbed can be expanded, and the fully closed position accuracy with respect to the throttle valve 4 can be improved.

(3) Feature point for Study Item 4 (Third feature point)
The only button-type stopper 21 has a receiving portion 22 for receiving the downstream side of the valve body 3, and this receiving portion 22 is downstream of the valve body 3 as shown in FIGS. 3 (a) and 3 (b). A receiving surface 22a that faces the side end surface 3b and directly contacts the end surface 3b has a convex curved surface 23. The stopper 21 has a receiving surface 22a where the receiving portion 22 forms an upstream end surface and a counter receiving surface 22b which forms a downstream end surface, and the counter receiving surface 22b also has a convex curved surface 23 similar to the receiving surface 22a. Presents.
The throttle valve 4 is regulated in its fully closed position by the downstream end surface 3b of the valve body 3 coming into contact with the receiving surface 22a (convex curved surface 23) of the receiving portion 22.

According to the above configuration, when the throttle valve 4 is in the fully closed position, the valve body 3 and the stopper 21 can be brought into contact with each other accurately without causing damage.
That is, the valve body 3 has a conventional structure, and the downstream end surface 3b is a flat surface, so that an inclined surface is formed at the fully closed position. On the other hand, the stopper 21 is shaped like a button having a short circumferential length S as shown in FIG. 4A even when the receiving portion 22 extends in the circumferential direction. Presents.
Even if the protruding position of the stopper 21 varies due to the combination described above and a relative positional shift occurs between the valve body 3 and the stopper 21, as shown in FIGS. 3A and 3B, the downstream side of the valve body 3. The side end surface 3b can be smoothly seated against the receiving surface 22a (convex curved surface 23) of the stopper 21. For this reason, the situation where the valve body 3 hits the edge part of the stopper 21 and causes damage to both does not occur.
Further, since the relative displacement between the valve body 3 and the stopper 21 is caused by dimensional tolerances and manufacturing errors, tolerances and errors on the design surface and manufacturing surface can be reduced.
Therefore, even if a simple design / manufacturing method is adopted, the valve body 3 and the stopper 21 can be brought into contact with each other accurately without causing damage, and the valve body in the fully closed position according to the above feature points can be brought into contact. The high precision effect can be further promoted.

In the first embodiment described above, as the second feature point, the protruding position of the stopper 21 is set to a location (area) where only the tip portion 32 of the valve body 3 is received with respect to the valve body 3. However, the relationship between the stopper 21 and the valve body 3 is as shown in FIG. 4 (b), where the angle formed by the tangent to the convex curved surface 23 of the stopper 21 and the downstream end face 3b of the valve body 3 is referred to as Y. It is important that Y satisfies positive (Y> 0), and the limit of the receiving position at the distal end portion 32 of the valve body 3 is slightly inside the outer peripheral edge (shaft 2, axis side) at the distal end portion 32. It is preferable.
Thereby, it can prevent that the edge part (outer periphery) of the front-end | tip part 32 of the valve body 3 hits against the receiving surface 22a of the stopper 21, and is damaged.

[Example 2]
Next, as another embodiment of the device of the present invention, Example 2 will be described based on FIG. 5 with a focus on differences from Example 1 described above.

  The second embodiment corresponds to a modification of the third feature point with respect to the examination item 4 described above. The only button-type stopper 21 has a convex curved surface 23 formed on the receiving surface 22a of the receiving portion 22. The shape is selected as a specific shape. The first example is a case formed on an arcuate surface (R surface) 23A as shown in FIG. 5 (a), and the second example is a case formed on a spherical surface 23B as shown in FIGS. 5 (b) and 5 (c). It is.

According to the above configuration, the valve body 3 and the stopper 21 can be brought into contact with each other more accurately, and the fully closed position of the throttle valve 4 can be regulated with higher accuracy.
When formed on the arcuate surface (R surface) 23A shown in FIG. 5A, the downstream end surface 3b of the valve element 3 is always one of the arcuate surfaces 23A even if the protruding position of the stopper 21 varies. The valve body 3 can be brought into contact with the stopper 21 with certainty in line contact with the surface.
5B and 5C, the downstream end surface 3b of the valve body 3 and the spherical surface 23B are brought into point contact with each other. Even if the position of the valve body 3 is shifted in the orthogonal direction, the downstream end surface 3b of the valve body 3 is always brought into point contact with one of the surfaces of the spherical surface 23B, so that the valve body 3 is surely applied to the stopper 21. Can be touched.
In the case of the spherical surface 23B, the upstream end face exhibits a kind of smooth streamline from the upstream side to the downstream side as shown in FIG. 5C, so that the turbulence in the air flow path 10 is reduced. And pressure loss can be reduced.

[Example 3]
Next, as another embodiment of the apparatus of the present invention, Example 3 will be described with reference to FIGS. 6A and 6B, focusing on the differences from Examples 1 and 2 described above.

Specific protrusion methods for the button-type stopper 21 can be broadly classified into “rear assembly method” and “integral formation method”. Can be projected by the method.
Incidentally, the former “rear assembly method” is a method in which the button-type stopper 21 is manufactured as an independent component different from the throttle housing 1 and is fixed to the inner wall surface 13 of the throttle housing 1 (broken line in FIG. 2). Reference). In this case, the shape of the button-type stopper 21 can be selected relatively freely, and the manufacturing method of the throttle housing 1 itself may be the same as before, which is advantageous when there are many variations as the throttle device 100.
The latter “integrated formation method” is a method in which the button-type stopper 21 is integrally formed on the inner wall surface 13 of the throttle housing 1, that is, the button-type stopper 21 is formed when the throttle housing 1 is manufactured by die casting or injection molding. (See FIG. 3). In this case, since the button-type stopper 21 can be manufactured at the same time when the throttle housing 1 is manufactured, it is particularly useful when there are few variations as the throttle device 100.

In the above-described first and second embodiments, an embodiment that basically employs the latter “integrated formation method” is illustrated.
However, when a protrusion is integrally formed in the air flow path 10 of the throttle housing 1, if there is a vertex in the protrusion, the structure of the mold must be split with the vertex as a boundary. There is a possibility that burrs are easily generated in the split mold portion, and the burrs cause turbulence in the air flow path 10 and may cause pressure loss.

The third embodiment shows an optimal example in the case where the latter “integrated formation method” is adopted as a method for projecting the button-type stopper 21.
The button-type stopper 21 is integrally formed on the inner wall 13 of the throttle housing 1 and is provided along the air flow path 3 as shown in FIG. And the top surface which faces the air flow path 10 is exhibiting the smooth flat surface 24 with respect to the axial direction of the air flow path 10, as shown in FIG.6 (b).

According to the third embodiment, the button-type stopper 21 has a flat surface 24 whose top surface facing the air flow path 10 is smooth with respect to the axial direction of the air flow path 10. The plane 24 can be removed. That is, as shown in FIG. 6B, it is possible to divide the boundary line between the receiving surface 22a (or the receiving surface 22b) and the flat surface 24 in the left-right direction as shown in FIG. Therefore, it is possible to suppress the occurrence of burrs that may cause turbulent flow in the air flow path 10 and cause pressure loss.
The flat surface 24 is not limited to a horizontal plane with respect to the axial direction of the air flow path 10, and may be an inclined surface that is inclined in only one direction with respect to the axial direction of the air flow path 10.

[Modification]
As mentioned above, although Example 1-3 of this invention was demonstrated in detail, these are only illustrations and a various change is possible in the range which does not deviate from the summary of this invention.
(1) In the first embodiment, the button-type stopper 21 is not limited to the rectangular shape illustrated in FIG. 4A, but is an inverted triangle in which the circumferential length S gradually decreases toward the downstream side. Various shapes can be employed, such as forming a shape or forming the upstream end surface into a convex curved surface.
(2) In the first to third embodiments, the stopper 21 has a symmetrical shape in which the downstream end surface (receipt surface 22b) side forms the same convex curved surface 23 as the receiving surface 22a side, but the downstream end surface (receipt) Of course, the surface 22b) does not necessarily have to be the convex curved surface 23.

(3) In the above embodiment, the present invention is applied to an electronic throttle device in which the valve 4 is driven by the motor 5. However, the present invention is not limited to this, and the valve 4 is not limited to the drive system of the valve 4. The present invention can be widely applied to all types that accommodate the butterfly valve 4.

  DESCRIPTION OF SYMBOLS 1 ... Throttle housing (valve housing), 2 ... Shaft (rotating shaft, axis), 3 ... Valve body, 3a ... Upstream side end surface, 3b ... Downstream side end surface, 4 ... Throttle valve (butterfly type valve), 10 ... Air Flow path, 10a ... one end, 10b ... other end, 20 ... stopper mechanism, 21 ... button (button) type stopper, 22 ... receiving portion, 22a ... receiving surface, 23 ... convex curved surface, 23A ... arc surface (R surface), 23B ... spherical surface, 31 ... root part of the valve body 3, 32 ... tip part (region) of the valve body 3, C ... air cleaner (air intake side), M ... intake manifold (suction side), L ... line.

Claims (7)

A valve having an air flow path (10) having one end (10a) connected to the upstream side air intake side (A) and the other end (10b) connected to the downstream side intake side (M) of the internal combustion engine. A housing (1);
A plate-like valve body (3) accommodated in the air flow path, and the valve body rotates about an axis (2) transversely orthogonal to the air flow path, A butterfly valve (4) for opening and closing the flow path;
A stopper mechanism (20) for directly restricting the rotational position of the valve by the rotational position of the valve body;
An intake negative pressure generator for an internal combustion engine that generates an intake negative pressure downstream of the air flow path by closing the air flow path,
The stopper mechanism protrudes like a button from the inner wall surface (13) forming the air flow path of the valve housing, and is the only button-type stopper (21 that restricts only the fully closed position of the valve body in the valve. )
The protruding position of the stopper is a region (32) having the longest length (L) from the rotation fulcrum (O) perpendicular to the axis on the rotation trajectory of the valve element, and the valve element. Located downstream of the
The stopper has a receiving portion (22) in which the receiving surface (22a) facing the downstream end surface (3b) of the valve body has a convex curved surface (23, 23A, 23B),
The intake negative pressure generating device for an internal combustion engine, wherein the valve has the fully closed position defined by a downstream end surface of the valve body coming into contact with a convex curved surface of the receiving portion. The intake negative pressure generator for an internal combustion engine according to claim 1,
The intake negative pressure generator for an internal combustion engine, wherein the stopper has a convex arc surface (23A). The intake negative pressure generator for an internal combustion engine according to claim 1,
The intake negative pressure generator for an internal combustion engine, wherein the convex curved surface of the stopper has a spherical surface (23B). The intake negative pressure generator for an internal combustion engine according to any one of claims 1 to 3,
For the internal combustion engine, the receiving portion of the stopper defines the fully closed position by abutting the convex curved surface with the downstream end surface located on the axial line side with respect to the valve. Negative pressure generator. The intake negative pressure generator for an internal combustion engine according to any one of claims 1 to 4,
The negative pressure generator for an internal combustion engine, wherein the button-type stopper is an independent component different from the valve housing, and is fixedly attached to an inner wall surface of the valve housing. The intake negative pressure generator for an internal combustion engine according to any one of claims 1 to 4,
The negative pressure generator for an internal combustion engine, wherein the button-type stopper is formed integrally with the valve housing. The intake negative pressure generator for an internal combustion engine according to claim 6,
The negative pressure generator for an internal combustion engine, wherein the button-type stopper has a flat surface (24) whose top surface facing the air flow path is smooth with respect to the axial direction of the air flow path.