Fluid control device

Abstract

The invention provides a fluid control device capable of suppressing the variation of the inter-shaft distance along with the rotation of a valve gear as much as possible. The fluid control device is provided with a valve gear (6) which is fixed on a shaft (4) for supporting a butterfly valve (5). An end portion of the shaft (4) is fixed to a shaft mounting hole (17) of a connecting member (16) of the valve gear (6) through an umbrella-shaped fixing portion (18). The area center of a region (A) of the shaft mounting hole (17) overlapping the umbrella-shaped fixing part (18) is positioned on a reference straight line (S) passing through the rotation center of the shaft (4), and in a fully closed state, the umbrella-shaped fixing part (18) is inserted into the umbrella-shaped fixing part (18). The magnitude of an angle ([theta] 2) formed in the closing direction by the reference straight line (S) with respect to a gear straight line (GL) passing through the center of rotation of a drive gear (8) for driving the valve gear (6) and the center of rotation of the shaft (4) is equal to or less than a movable angle ([theta] 1).

Description

Technical Field

[0001] The present invention relates to a fluid control device having a valve core that can rotate within a fluid passage of a body. Background Technology

[0002] In the prior art, in fluid control devices having a plate-shaped valve core that can rotate within the fluid passage of the main body, the valve core opens and closes the fluid passage by rotating a shaft that holds the valve core. The rotation of the shaft is achieved by using an electric motor to rotate a valve gear fixed to one end of the shaft (for example, see Patent Document 1).

[0003] In the fluid control device of Patent Document 1, the shaft is fixed to the valve gear by inserting the end of the shaft into the shaft mounting hole of the connecting component that is fixed to the valve gear, allowing it to protrude slightly, and then riveting the end from the protruding side. During this riveting process, the deformation of the end caused by the riveting process fills multiple recesses that are radially outwardly recessed in the shaft mounting hole, and covers the protruding side of the end of the shaft mounting hole in an umbrella shape.

[0004] In addition, when forming a gear on the outer periphery of the connecting component, when inserting the end of the locating pin into the shaft mounting hole of the connecting component in the forming mold, in order to make the connecting component inserted relative to the locating pin in a uniform and predetermined rotational direction angle, several of the multiple recesses in the shaft mounting hole have a different shape from the other recesses.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-100598 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, according to the device in Patent Document 1, some of the recesses in the shaft mounting hole have different shapes from the other recesses. Therefore, when the shaft is inserted into the shaft mounting hole with a clearance fit and the end of the shaft is riveted, the central axis of the valve gear is displaced relative to the central axis of the shaft, resulting in eccentricity.

[0010] The misalignment of the central shaft causes a change in the center-to-center distance between the valve gear and the drive gear that drives it, i.e., the inter-shaft distance (gear spacing). This change in inter-shaft distance varies depending on the rotation angle of the valve gear. Consequently, the gear meshing rate deteriorates, potentially leading to a reduction in gear wear life.

[0011] The object of the present invention is to, in view of the above-mentioned problems of the prior art, suppress as much as possible the variation of the inter-shaft distance with the rotation of the valve gear in the fluid control device.

[0012] Methods for solving problems

[0013] The fluid control device of the present invention comprises: a main body having a fluid passage; a plate-shaped valve core supported by the main body via a shaft for rotatability, for opening and closing the fluid passage; and a valve gear fixed to one end of the shaft and rotated by an electric actuator.

[0014] The valve gear is configured such that it can rotate within a range of less than 90° of movable angle between the fully open and fully closed states of the valve core by meshing with a drive gear driven by the electric actuator. The valve gear is provided with a connecting component having a shaft mounting hole through which one end of the shaft passes.

[0015] One end of the shaft passing through the shaft mounting hole is fixed to the shaft mounting hole by an umbrella-shaped fixing part formed by plastic deformation toward the radially outward side of the shaft.

[0016] When viewed along the axis, the center of the area of ​​the shaft mounting hole overlapping with the umbrella-shaped fixing part lies on a reference line passing through the rotation center of the axis. Furthermore, when viewed along the axis, in the fully closed state of the valve core, the angle formed by the reference line with respect to the gear line connecting the rotation center of the drive gear and the rotation center of the shaft is less than the movable angle of the valve core in the direction of closing the valve core.

[0017] According to the present invention, the center of the area of ​​the shaft mounting hole overlapping with the umbrella-shaped fixing part is located on a reference line passing through the rotation center of the shaft, and in the fully closed state of the valve core, the angle between the reference line and the gear line is less than the movable angle of the valve core in the direction of closing the valve core, so as to suppress the change of the shaft distance with the rotation of the valve gear as much as possible. Attached Figure Description

[0018] Figure 1 This is a front view showing the main parts of the intake control device according to an embodiment of the present invention, viewed by removing the gearbox housing along the axial direction.

[0019] Figure 2 It means Figure 1 The structure near the top end of the shaft in the intake control device Figure 3 Sectional view along line II-II.

[0020] Figure 3This indicates that the view is taken from the top side along the axis. Figure 2 A diagram showing the situation near the top of the axis.

[0021] Figure 4 This is a diagram showing the connecting components of an existing intake control device.

[0022] Figure 5 It represents the amount of change in the inter-axis distance relative to Figure 1 A graph showing the changes in the opening degree of the intake control device.

[0023] Figure 6 It means to Figure 5 A chart showing the rate of change of the inter-axis distance obtained by differentiating the original chart.

[0024] Figure 7 It means that it is able to Figure 1 A diagram showing a modified example of a connecting component used in a fluid control device.

[0025] Figure 8 It means that it is able to Figure 1 Figures show other variations of connecting components used in fluid control devices. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. Figure 1 The figure shows the main parts of an electronically controlled intake control device according to one embodiment of the fluid control device of the present invention. As shown in the figure, the intake control device 1 includes: a main body 3 having an intake passage 2 forming a fluid passage; and a butterfly valve 5 having a plate-shaped valve core, which is rotatably supported by the main body 3 via a shaft 4 to open and close the intake passage 2.

[0027] A valve gear 6, which rotates using an electric actuator, is fixed to one end of shaft 4. Here, an electric motor 7 is used as the electric actuator. The valve gear 6 is configured such that, by meshing with a drive gear 8 driven by the electric motor 7, it can rotate within a range of movable angle θ1 of less than 90° corresponding to the fully open and fully closed states of the butterfly valve 5. Figure 1 In the middle, the butterfly valve 5 is represented by a dashed line, where the valve gear 6 abuts against the fully closed stop 9 on the main body 3 and is in a fully closed state.

[0028] The electric motor 7 drives the drive gear 8 via a pinion 10 located on the output shaft of the electric motor 7 and meshing with the drive gear 8. The drive gear 8 includes a large gear 11 that meshes with the pinion 10 and a pinion 12 fixed coaxially relative to the large gear 11. The valve gear 6 meshes with the pinion 12 of the drive gear 8. The gear mechanism including the valve gear 6, the drive gear 8, and the pinion 10 is housed in the gearbox GC. Figure 1 The image shows the state after the gearbox GC casing has been removed.

[0029] The valve gear 6 is forced in the direction of closing the intake passage 2 of the butterfly valve 5 (closing direction) by the return spring 13 located between it and the main body 3. In addition, the valve gear 6 is forced in the direction of opening the butterfly valve 5 (opening direction) by the default spring 14 within the angle range corresponding to the closed position and the specified default position of the butterfly valve 5, wherein the default spring 14 is disposed inside the return spring 13 and between the return spring 13 and the main body 3.

[0030] The valve gear 6 is rotated by the electric motor 7 in a manner that overcomes the forces of the return spring 13 and the default spring 14, thereby bringing the butterfly valve 5 to the required opening degree. If the electric motor 7 is unable to operate due to a malfunction, the default spring 14 functions as a default mechanism 15, keeping the butterfly valve 5 in its default position. The opening degree of the butterfly valve 5 in its default position, i.e., the default angle, is an intermediate opening angle within the range of the movable angle θ1.

[0031] A connecting component 16 is provided on the valve gear 6 for fixing the valve gear 6 to one end of the shaft 4. A shaft mounting hole 17 is provided on the connecting component 16 for passing through and fixing the one end.

[0032] Figure 2 The structure near the top of shaft 4 is shown. (As shown) Figure 2 As shown, one end of the shaft 4 passing through the shaft mounting hole 17 is fixed to the shaft mounting hole 17 along the length direction of the shaft 4 by an umbrella-shaped fixing part 18 formed by plastic deformation toward the radially outward side of the shaft 4. The umbrella-shaped fixing part 18 is composed of a portion located further outward than the diameter of one end of the shaft 4. The umbrella-shaped fixing part 18 can be formed by rotational riveting. At this time, the material at the top end of the shaft 4 undergoes plastic deformation and flows in the direction of the arrow in the figure, thereby forming the umbrella-shaped fixing part 18.

[0033] Figure 3 This indicates the view near the top of axis 4 as seen from the top side along the direction it extends. For example... Figure 3 As shown, the peripheral wall 19 of the shaft mounting hole 17 is formed in a spline shape that alternately bends along the outer periphery 20 of the umbrella-shaped fixing part 18 to the outer and inner sides of the outer periphery 20.

[0034] The spline shape is approximately tangent to each vertex of a regular octagon centered at the rotation center P1 of axis 4, with respect to a circle having the same diameter as one end of axis 4. Between each tangent position, eight recesses are formed that curve radially outward. These eight recesses consist of three reference recesses 21a of the same shape and five additional standard recesses 21b of the same shape. The radially outer depth of the reference recesses 21a is greater than that of the standard recesses 21b.

[0035] The three reference recesses 21a serve as references for arranging the connecting component 16 in a suitable position relative to the top of the locating pin within the mold. The deepest parts of two of the three reference recesses 21a are located on the gear line GL passing through the rotation center P2 of the drive gear 8 and the rotation center P1 of the shaft 4 (see reference). Figure 1 On. In addition, in this embodiment, the deepest part of another reference recess 21a is located on the reference line S described later, but it is not limited to this shape.

[0036] When the umbrella-shaped fixing part 18 is formed, the material at the top end of the shaft 4 undergoes plastic deformation through rotational riveting and flows into the reference recess 21a and the standard recess 21b, thereby fixing the connecting part 16 to the top end of the shaft 4 in a prescribed posture.

[0037] The reference straight line S is a straight line passing through the rotation center P1 of shaft 4 and through the area center (geometric center) C of region A (shaded area), where region A is the area where shaft mounting hole 17 overlaps with umbrella-shaped fixing part 18. Additionally, in the fully closed state of butterfly valve 5 closing intake passage 2 ( Figure 1 , Figure 3 In the state shown, the reference straight line S forms an angle θ2, which is less than the aforementioned movable angle θ1, relative to the gear straight line GL in the direction where the butterfly valve 5 is closed.

[0038] The fact that the reference line S passes through the area center (geometric center) C means that, during the formation of the umbrella-shaped fixing part 18, a greater amount of the plastically deformed material of the shaft 4 flows from the rotation center P1 towards the area center C in the direction D1. This implies that when the material of the shaft 4 undergoes plastic deformation radially outward due to rotational riveting and flows into the reference recesses 21a and standard recesses 21b, the resistance encountered is greater at the recesses 21b than at the reference recesses 21a.

[0039] That is, the forces F1, F5, and F8 exerted by the material portion of the shaft 4 that pushes against the reference recess 21a are smaller than the forces F2 to F4, F6, and F7 exerted against the standard recess 21b. Therefore, when forming the umbrella-shaped fixing part 18, the material of the shaft 4 applies a resultant force F of forces F1 to F8 to the connecting member 16, pushing the connecting member 16 in the direction opposite to direction D1. That is, this force F is generated because the force F8 exerted on the reference recess 21a located on the reference straight line S is smaller.

[0040] Therefore, when the umbrella-shaped fixing part 18 is formed, the connecting part 16 loosens in the direction of force F due to the material of the shaft 4. That is, the connecting part 16 is fixed to the shaft 4 by slightly shifting from its correct position, which is aligned with the rotation center P1 of the shaft 4, in the direction of force F along the reference line S due to the presence of force F.

[0041] When the intake control device 1 with this structure is in operation, the connecting component 16, together with the valve gear 6, can use the electric motor 7 to form an angle θ2 from the reference line S and the gear line GL within the range of movable angle θ1. Figure 3 When fully closed, it rotates in the opening direction (clockwise relative to the drawing). During this period, the connecting component 16 loosens (displaces) in the direction of force F, therefore, as... Figure 3 As shown, the center position of valve gear 6 is slightly shifted from the center position Pc when fully closed to the center position Po when fully open.

[0042] During this period, such as Figure 3 As shown, the angle θ2 formed by the reference straight line S in the closing direction relative to the gear straight line GL when fully closed is an angle less than or equal to the movable angle θ1. Therefore, the variation Δx of the component of the loosening amount of the connecting part 16 in the direction of the loosening direction along the gear straight line GL becomes the maximum value Δx1 when the reference straight line S coincides with the gear straight line GL, and becomes the minimum value when the center position of the valve gear 6 is at the center position Pc when fully closed or the center position Po when fully open.

[0043] In particular, when the reference straight line S is fully closed and the angle θ2 formed with respect to the gear straight line GL is half the movable angle θ1, the looseness (variation Δx) along the gear straight line GL at the center position Pc and the center position Po is consistent, and the maximum value of the variation Δx, Δx1, is the smallest.

[0044] In contrast, in such Figure 4 In the case of the connecting component 16P in the existing example shown, the reference straight line S where the area center C of the region A overlapping with the umbrella-shaped fixing part 18 of the shaft mounting hole 17 is located is at an angle θ2 relative to the gear straight line GL in the closing direction when the butterfly valve 5 is fully closed. This angle is greater than or equal to the movable angle θ1.

[0045] Therefore, the center position of the valve gear 6 undergoes a large displacement in the direction along the gear straight line GL between the center position Pc when fully closed and the center position Po when fully open. Consequently, the maximum value of the variation Δx of the component of the looseness of the connecting part 16P along the gear straight line GL becomes a much larger maximum value Δx2 than the maximum value Δx1 in this embodiment.

[0046] Figure 5 This is a graph showing the variation of the inter-shaft distance relative to the opening degree in this embodiment and the prior art. The horizontal axis of the graph is the opening degree, which is zero when fully closed, and the vertical axis is the variation of the inter-shaft distance Δx (mm), which is zero when fully closed. The larger the variation Δx, the closer the valve gear is to the drive gear.

[0047] In this embodiment, graph curve C1 represents the case where the angle θ2 formed by the reference line S relative to the gear line GL in the closing direction when fully closed is approximately 0.5 times the movable angle θ1. In the conventional example, graph curve C2 represents the case where the angle θ2 formed by the reference line S relative to the gear line GL in the closing direction when fully closed is approximately 1.5 times the movable angle θ1.

[0048] according to Figure 5 As can be seen from the graphs, the maximum value Δx1 of the inter-axis distance variation Δx in the present embodiment, as shown by graph curve C1, is much smaller than the maximum value Δx2 of the inter-axis distance variation Δx in the conventional example, as shown by graph curve C2.

[0049] Figure 6 It means to Figure 5 This is a graph showing the rate of change of the inter-axis distance obtained by differentiating the graph. The vertical axis represents the rate of change of the inter-axis distance Fr (mm / deg) corresponding to the opening on the horizontal axis. Graph curve C3 represents the rate of change in the case of this embodiment. Graph curve C4 represents the rate of change in the case of the conventional example.

[0050] according to Figure 6 As can be seen, in the present embodiment shown in graph C3, the rate of change of the inter-axis distance Fr is larger when fully closed and fully open, but quite small at the intermediate opening where it is used most frequently. In contrast, in the conventional example shown in graph C4, the rate of change of the inter-axis distance Fr is greater than that in the fully open region from fully closed to fully open in the present embodiment.

[0051] As described above, according to this embodiment, the valve is configured such that, in the fully closed state of the butterfly valve 5, the angle θ formed by the reference line S with respect to the gear line GL is an angle less than or equal to the movable angle θ1 in the direction in which the butterfly valve 5 is closed. Therefore, compared to conventional methods, it is more effective in suppressing variations in the inter-axial distance between the valve gear 6 and the drive gear 8 caused by the rotation of the valve gear 6. This, in turn, improves the wear life of each gear.

[0052] Furthermore, in the fully closed state, by making the angle θ2 formed by the reference straight line S relative to the gear straight line GL in the closing direction approximately half of the movable angle θ1, the maximum value Δx1 of the variation in the distance between shafts Δx can be minimized.

[0053] Figure 7 This illustrates a variation of the connecting component. In the shaft mounting hole 17b of this connecting component 16b, the shape of the reference recess 21c is similar to... Figure 3 The reference recess 21c differs from the arc-shaped reference recess 21b. The reference recess 21c has an isosceles triangular shape, with a apex that is partially rounded on the radially outer side. Regarding other aspects, it has the same... Figure 3 The connecting component 16 has the same structure.

[0054] In this case, with Figure 3 Similar to the case of the connecting component 16, the center C of the area A of the shaft mounting hole 17b overlapping with the umbrella-shaped fixing part 18 is located on the reference line S. Therefore, when forming the umbrella-shaped fixing part 18, the direction in which the connecting component 16b is loosened by the shaft 4 is along the reference line S away from the reference recess 21c located on the reference line S. Therefore, in this case, it is also possible to achieve the same effect as... Figure 3 The same effect is achieved with component 16 as in the case of the connection.

[0055] Figure 8 This illustrates another variation of the connecting component. The connecting component 16c has the following shape: centered on the rotation center P1 of shaft 4, it... Figure 7 The shape of the shaft mounting hole 17c of the connecting component 16b is rotated 180° to its original shape. Regarding other aspects, it has the same... Figure 7 The connecting component 16b has the same structure.

[0056] In this case, one of the three reference recesses 21d is located on the reference line S, therefore, with Figure 7 Similar to the case of the connecting component 16b, the area center C of the region A overlapping with the umbrella-shaped fixing part 18 of the shaft mounting hole 17 is located on the reference line S. The area center C is located at the rotation center P1 relative to the shaft 4. Figure 4 The opposite side of the situation.

[0057] Therefore, in this case, the connecting component 16c also loosens along the reference line S relative to the rotation center P1 in a direction opposite to the area center C, but the direction of the force F from the shaft 4 is opposite to... Figure 7 The connecting component 16 is in the opposite direction, therefore, towards the opposite direction. Figure 7 The connection component 16b is loose in the opposite direction.

[0058] However, in this case, the variation Δx of the looseness of the connecting component 16 along the gear straight line GL becomes the maximum value Dx3 when the reference straight line S coincides with the gear straight line GL, and the variation Δx becomes the minimum when the center position of the valve gear 6 is at the center position Pc when fully closed or the center position Po when fully open.

[0059] exist Figure 5 and Figure 6 In the figure, curves C5 and C6 represent the change in inter-axis distance Δx and the rate of change Fr, respectively. According to curves C5 and C6, in this case... Figure 8 In the case of the connecting component 16c, it can also function in relation to the variation amount Δx and the variation rate Fr. Figure 3 The same effect is achieved with component 16 as in the case of the connection.

[0060] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the fully closed state of the butterfly valve 5, the angle θ2 formed by the reference straight line S relative to the gear straight line GL in the direction of closing the butterfly valve 5 can also be an intermediate opening angle smaller than the movable angle θ1, that is, the default angle mentioned above.

[0061] Therefore, it is possible to improve the accuracy of the gear spacing (shaft-to-shaft distance) near the most stringent intermediate opening angle, which is related to gear wear. This, in turn, can suppress gear wear near the intermediate opening angle.

[0062] Symbol Explanation

[0063] 1: Intake control device; 2: Intake passage; 3: Throttle valve; 4: Shaft; 5: Butterfly valve; 6: Valve gear; 7: Electric motor; 8: Drive gear; 9: Fully closed stop; 10: Pinion; 11: Large gear; 12: Pinion; 13: Return spring; 14: Default spring; 16, 16b, 16c: Connecting parts; 17: Shaft mounting hole; 18: Umbrella-shaped fixing part; 19: Peripheral wall; 20: Outer periphery; 21a, 21c, 21d: Reference recess; 21b: Standard recess; A: Area; C: Area center; C1~C6: Curve; GL: Gear straight line; P1, P2: Rotation center; Pc, Po: Center position; S: Reference straight line.

Claims

1. A fluid control device, comprising: The main body, which has fluid pathways; A plate-shaped valve core, rotatable and supported by the body via a shaft, opens and closes the fluid passage; and, A valve gear, fixed to one end of the shaft, is rotated by an electric actuator. The fluid control device is characterized in that... The valve gear is configured such that, by meshing with a drive gear driven by the electric actuator, it can rotate within a movable angle range of less than 90° between the fully open and fully closed states of the valve core. The valve gear is provided with a connecting component having a shaft mounting hole through which one end of the shaft passes. One end of the shaft passing through the shaft mounting hole is fixed to the shaft mounting hole by an umbrella-shaped fixing part formed by plastic deformation toward the radially outward side of the shaft. When viewed along the axis, the center of the area of ​​the region where the shaft mounting hole overlaps with the umbrella-shaped fixing part lies on a reference straight line passing through the rotation center of the shaft. When viewed along the axis, in the fully closed state of the valve core, the angle between the reference line and the gear line connecting the rotation center of the drive gear and the rotation center of the shaft is less than the movable angle in the direction of closing the valve core.

2. The fluid control device according to claim 1, characterized in that, Equipped with a default mechanism, when the driving force from the electric actuator is removed, the default mechanism maintains the valve opening at the middle opening angle within the range of movable angles. In the fully closed state, the angle between the reference straight line and the gear straight line is approximately the intermediate opening angle.

3. The fluid control device according to claim 1, characterized in that, In the fully closed state, the angle between the reference line and the gear line is approximately half of the movable angle.

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