Leak preventing valve structure of variable induction system and assembly method thereof

Abstract

A leak prevention valve structure for a variable intake system and a method of assembling the same are disclosed, which are mounted on a variable intake system having N intake passages, and include a pivot shaft equipped with a valve flap that opens and closes the N intake passages, and a detachable valve flap that is detachably mounted on the pivot shaft, wherein the pivot shaft and each detachable valve flap are coupled by a spring to prevent leakage from each detachable valve flap. The leak prevention valve structure of a variable intake system according to the present invention is characterized in that one or more through holes are formed in the pivot shaft, a coupling groove is formed inside the body of the detachable valve flap, a spring passes through the through hole of the pivot shaft and is inserted into the coupling groove, thereby coupling the detachable valve flap to the pivot shaft, and the detachable valve flap receives an elastic force in a direction perpendicular to the axial direction of the pivot shaft by the spring.

Description

Technology Field

[0001] The present invention relates to a leak-prevention valve structure for a variable intake system and a method of assembling the same. More specifically, the invention relates to a structure and a method of assembling the same, which is mounted on a variable intake system having N intake passages, comprising a pivot shaft equipped with a valve flap that opens and closes the N intake passages, and a detachable valve flap detachably mounted on the pivot shaft, wherein the pivot shaft and each detachable valve flap are coupled by a spring to prevent leakage from each detachable valve flap. Background Technology

[0003] Engines that generate propulsion in automobiles or ships use the energy produced by burning a mixture of fuel and air in appropriate proportions within the combustion chamber formed between the cylinder block and the cylinder head cover as driving force.

[0005] Furthermore, engine performance is largely determined by volumetric efficiency, that is, how much air can be drawn into the combustion chamber. Generally, in the low and medium speed ranges, engines exhibit contrasting characteristics: longer ports with smaller diameters are advantageous for increasing volumetric efficiency, whereas in the high speed range, shorter ports with larger diameters lead to higher volumetric efficiency.

[0007] To optimize these engine characteristics and improve engine performance across the entire load range, a Variable Induction System (VIS) is used, which changes the flow path of the gas passing through the intake port to be longer in the low and medium speed ranges and shorter in the high speed range.

[0009] An engine intake device using a typical variable intake system consists of a manifold body with multiple ports, through which gas flow occurs, and the length of the flow path at each port is controlled by a valve. The valve is installed in the manifold body to pass through each port laterally and opens and closes the port by reciprocating around a valve axis. Since the gas flow path at the port becomes longer or shorter when the port is opened or closed, high volumetric efficiency can be maintained across the entire load range of the engine.

[0011] In order to improve engine performance using a variable intake system, air leakage must not occur by ensuring that the valve flap is in close contact with the port surface. As a representative prior art related to this, prior art document 1 (Korean Registered Patent 10-0747175) discloses a technology in which, as shown in FIG. 1, a rib made of silicone rubber is formed on the edge of the valve flap, and a recessed strip-shaped seat surface is provided so that the edge of the valve flap can be seated on an insert shell forming the inlet of the intake manifold.

[0012] In addition, the technology of prior art document 1 has a valve flap integrally formed on a pivot shaft, and since it is mounted on a port surface while being integrally formed with multiple valve flaps and the pivot shaft, it has good assembly and durability. However, if the number of valve flaps increases, twisting of the pivot shaft during valve operation cannot be avoided, and especially since it is made of plastic, there is a possibility of deformation due to high heat generated in the engine, and as a result, a phenomenon in which airtightness between the valve flap and the seat surface is not secured, that is, a lifting phenomenon may occur.

[0014] As another technology, prior art document 2 (Korean Registered Patent 10-1531331) is proposed to solve the problem of the prior art of assembling valve flaps assembled in a housing shell part together with a cage and bearings by inserting a long shaft, and discloses a plurality of bearings and a plurality of valve flaps integrally injection molded on a shaft.

[0015] That is, the invention discloses a technology comprising a shaft, a plurality of bearings and a plurality of valve flaps injection-molded on the shaft; and a plurality of cages assembled to a housing shell part together with the plurality of valve flaps while assembled to the plurality of bearings.

[0016] However, the technology of prior art document 2 also has the problem that when the number of valve flaps increases, the twisting phenomenon of the rotational shaft during valve operation cannot be avoided, and thus the phenomenon of not securing airtightness between the valve flap and the seat surface, i.e., the lifting phenomenon, cannot be resolved.

[0018] Meanwhile, although there are known technologies that improve airtightness between the valve flap and the inlet by utilizing the spring force of a spring positioned on one side of the valve shaft, these technologies can only be installed on a single valve flap provided in the intake port, and thus have the problem of being difficult to apply to configurations where multiple valve flaps are installed on a single pivot axis, as described in prior art document 1 or prior art document 2.

[0019] In other words, with the conventional technology of placing a spring between the pivot shaft and one side of the intake port to apply elastic force to a single valve flap, when multiple valve flaps are mounted on a single pivot shaft, spring force cannot be applied to each valve flap, and thus airtightness of each valve flap cannot be ensured.

[0020] In addition, to improve the airtightness of the valve flap, one might consider increasing the driving force applied to the valve pivot shaft, but if excessive driving force is applied, the risk of damage to the rubber sealing part at the edge of the valve flap increases, and when multiple valve flaps are mounted on the pivot shaft, each valve flap does not sit on the seat surface with the same pressure due to manufacturing tolerances, etc., resulting in a problem where airtightness is not achieved smoothly. Prior art literature

[0022] Korean Registered Patent 10-0747175 (Publication Date: Aug. 1, 2007) Korean Registered Patent 10-1531331 (Publication Date: June 25, 2015) Korean Registered Patent 10-1567698 (Publication Date: Nov. 23, 2015) The problem to be solved

[0023] In variable intake systems with N intake passages, valve structures in which multiple valve flaps are combined on a single pivot shaft to open and close the N intake passages are frequently used due to assembly convenience and a simple structure. However, in such conventional valve structures, twisting of the pivot shaft during valve actuation is unavoidable. Consequently, particularly in the case of valve flaps located far from the position where the driving force is transmitted, a phenomenon known as "lifting" may occur, in which airtightness between the valve seating surfaces of the intake passages is not ensured.

[0024] Accordingly, the present invention aims to provide a leak-prevention valve structure and a method of assembling the same, which improve engine performance by preventing air leakage that may occur at each valve flap in each intake passage and thereby promoting ideal operation of the variable intake system.

[0025] In addition, although the valve structure of the conventional variable intake system does not cause any problems with the operation of the variable intake system in the initial assembled state, there is a problem in that air leakage occurs as a gap develops between the valve flap and the valve seating surface of the intake passage due to causes such as thermal deformation over time.

[0026] However, conventional technology is not equipped with any configuration to compensate for this gap, so the amount of leakage gradually increases, causing the variable intake system to malfunction and engine performance to gradually deteriorate.

[0027] The present invention aims to overcome the problems of the prior art by proposing a leak-prevention valve structure for a variable intake system having a unique structure capable of responding to such aging changes, and by providing a method for assembling the same. means of solving the problem

[0029] According to one embodiment of the present invention as a means of solving the problem,

[0030] The present invention provides a leak prevention valve structure for a variable intake system having N intake passages, comprising a pivot shaft equipped with valve flaps that open and close the N intake passages, and at least one detachable valve flap among the N valve flaps that is detachably mounted on the pivot shaft, wherein one or more through holes are formed in the pivot shaft and a coupling groove is formed inside the body of the detachable valve flap, and a spring passes through the through hole of the pivot shaft and is inserted into the coupling groove so as to connect the detachable valve flap to the pivot shaft, and the detachable valve flap receives an elastic force in a direction perpendicular to the axial direction of the pivot shaft by the spring.

[0032] Here, among the N valve flaps, N-1 detachable valve flaps are detachably mounted on the pivot shaft, and N-1 through holes are formed in the pivot shaft, and a coupling groove is formed inside the body of the detachable valve flap, so that a spring passes through the through holes of the pivot shaft and is fitted into the coupling groove of the detachable valve flap and fixed, thereby the N-1 detachable valve flaps receive an elastic force in a direction perpendicular to the axial direction of the pivot shaft.

[0034] In addition, among the N valve flaps, one integral valve flap is fixed integrally to the pivot shaft so as not to be detachably attached, and a fixing surface for fixing the integral valve flap is formed on the pivot shaft at the position where the integral valve flap is fixed, so that the integral valve flap can be fixed.

[0036] According to another embodiment of the present invention, the leak-prevention valve structure of the variable intake system of the present invention comprises N detachable valve flaps detachably mounted on the pivot shaft, N through holes are formed in the pivot shaft, and a coupling groove is formed inside the body of the detachable valve flap, so that a spring passes through the through holes of the pivot shaft and is fitted into the coupling groove of the valve flap and fixed, thereby allowing the N detachable valve flaps to receive an elastic force in a direction perpendicular to the axial direction of the pivot shaft.

[0038] In addition, the through hole formed in the above-mentioned pivot shaft has a cross-sectional shape that is slit-shaped, and the coupling groove formed in the above-mentioned detachable valve flap has a cross-sectional shape that is slit-shaped, and

[0039] Preferably, the spring is a plate spring having a cross-sectional shape corresponding to the cross-sectional shape of the through hole and the coupling groove.

[0041] In addition, a plate spring is fitted into the coupling groove of the detachable valve flap by passing through the through hole of the above-mentioned pivot shaft, and a valve cover can be attached to the surface of the detachable valve flap where the plate spring is inserted.

[0043] In addition, the body of the detachable valve flap may have a pivot shaft insertion hole formed therein for fitting into the pivot shaft, and a raised portion formed therein that surrounds the inserted pivot shaft, and a recess formed at the lower center of the upper surface of the body for the entry of the plate spring and the coupling of the valve cover, and a coupling groove formed inside the upper center of the body along the longitudinal direction of the detachable valve flap, so that the plate spring may be fitted into the through hole of the pivot shaft and the coupling groove of the detachable valve flap through the recess.

[0045] In addition, a gap is formed between the inner surface of the coupling groove of the detachable valve flap and the outer surface of the plate spring, and the gap can be set differently for each detachable valve flap in each intake passage, and the entry angle of the through hole formed in the pivot shaft can be set differently for each detachable valve flap in each intake passage.

[0047] In addition, the detachable valve flap and the integrated valve flap may be composed of a rigid body and a flexible perimeter, wherein the rigid body is made of plastic material and the flexible perimeter may be made of rubber or an elastic plastic material.

[0049] In addition, the leak prevention valve structure of the variable intake system according to one embodiment of the present invention may have the position of the detachable valve flap when it is fully opened determined by limiting the movement of the detachable valve flap by a stopper formed protruding from the inner wall of each intake passage.

[0051] As another embodiment of the present invention, a method for assembling a leak-prevention valve structure of a variable intake system according to the present invention may be performed by including the steps of machining a pivot shaft having a plurality of through holes, inserting a detachable valve flap into the pivot shaft, and inserting a spring into the pivot shaft and the detachable valve flap.

[0053] In addition, following the step of machining the aforementioned pivot shaft, the method may further include the step of injecting an integral valve flap as a plastic insert onto the pivot shaft and the step of molding the periphery of the integral valve flap with a flexible material.

[0055] In addition, the step of attaching a valve cover may be further included after the step of inserting a spring into the above-mentioned pivot shaft and the above-mentioned detachable valve flap. Effects of the invention

[0057] According to the leak-prevention valve structure of the variable intake system according to the present invention, even in a valve structure in which multiple valve flaps are coupled to a single pivot shaft, airtightness is maintained between each valve flap and the valve seating surface of the intake passage, thereby preventing air leakage, stable operation of the variable intake system is possible, and engine performance can be maintained.

[0058] In particular, in the case of conventional technology, when a gap occurs between the valve flap and the valve seating surface of the intake passage due to aging, there is no configuration to compensate for or prevent this, making it impossible to address air leakage; however, according to the present invention, this problem is resolved or mitigated, allowing the vehicle's performance to always be maintained at the initial state upon release.

[0059] In addition, since the valve flap is configured to be detachable, it allows for a more proactive response to air leakage problems by replacing the spring as needed or adjusting the gap between the coupling hole formed inside the valve flap and the spring. Brief explanation of the drawing

[0061] FIG. 1 is a valve structure of a conventional variable intake system. FIG. 2 is a cross-sectional perspective view of a variable intake system equipped with a leak prevention valve structure according to one embodiment of the present invention. FIG. 3 is a perspective view showing a leak prevention valve structure of a variable intake system according to two embodiments of the present invention. FIG. 4 is a cross-sectional perspective view showing a leak prevention valve structure of a variable intake system according to one embodiment of the present invention. FIG. 5 is a perspective view and a front view showing a pivot axis according to one embodiment of the present invention. FIG. 6 is a perspective view showing the components of a detachable valve flap according to one embodiment of the present invention. FIG. 7 is a cross-sectional perspective view AA of the body of the detachable valve flap shown in FIG. 6 and a cross-sectional perspective view showing the combined state of the components. FIG. 8 is a plan view and a cross-sectional view of a leak-prevention valve structure of a variable intake system according to another embodiment of the present invention. FIG. 9 is a plan view and a cross-sectional view of a leak prevention valve structure of a variable intake system according to another embodiment of the present invention. FIG. 10 is a perspective view of the valve flap opening and closing states of a variable intake system equipped with a leak prevention valve structure of a variable intake system according to an embodiment of the present invention. FIG. 11 is an overall process diagram showing a method for assembling a leak-prevention valve structure of a variable intake system according to an embodiment of the present invention. FIG. 12 is a later process diagram showing a method for assembling a leak-prevention valve structure of a variable intake system according to an embodiment of the present invention. Specific details for implementing the invention

[0062] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0063] In describing the present invention, the terms used in the specification below are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0064] Furthermore, terms such as “comprising” or “having” in this specification are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0065] In describing the invention with reference to the attached drawings, identical components are assigned the same reference numerals, and redundant descriptions of identical components are omitted. Furthermore, in describing the invention, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of the invention, such detailed description is omitted.

[0066] FIG. 2 is a cross-sectional perspective view of a variable intake system equipped with a leak prevention valve structure according to one embodiment of the present invention, and FIG. 3 is a perspective view showing a leak prevention valve structure of a variable intake system according to two embodiments of the present invention.

[0067] Referring to FIG. 2, a leak-prevention valve structure (100) according to an embodiment of the present invention is mounted on an intake manifold (10) of a variable intake system having four intake passages (12, 13, 14, 15). Although the intake manifold (10) shown in FIG. 2 is shown to have four intake passages, depending on the engine, N intake passages may be formed, such as 6, 8, 10, 12, etc., and N valve flaps (110, 120, 130, 140) that open and close the N intake passages may be seated in each intake passage.

[0068] And the leak prevention valve structure (100) of the present invention is configured to include a pivot shaft (190) equipped with valve flaps that open and close N intake passages, and at least one detachable valve flap among the N valve flaps that is detachably mounted on the pivot shaft. The embodiment of FIG. 2 shows an embodiment in which valve flaps (120, 130, 140) that open and close the second intake passage (12), the third intake passage (13), and the fourth intake passage (14) are configured as detachable valve flaps, as shown in FIG. 3 (a).

[0069] Meanwhile, with four valve flaps installed, one end of the pivot shaft (190) can be fitted into a coupling hole formed on one side of the intake manifold (10). FIG. 2 shows that a coupling hole is formed on the side of the fourth intake passage (14) of the intake manifold (10), and the right end of the pivot shaft (190) is inserted and coupled with a bearing (19) installed in the coupling hole.

[0070] In addition, a coupling surface (195) is formed at the right end of the pivot shaft (190) to which a pivot arm (22) is coupled so as to drive the rotational movement of the pivot shaft, and the pivot arm (22) is fixed, and the pivot arm (22) is connected to a link bar (21) that transmits the linear movement of the actuator (20), so that the pivot shaft (190) and the valve flaps (110, 120, 130, 140) mounted on the pivot shaft are rotated by the driving force of the actuator (20).

[0072] Next, a more detailed configuration of the leak prevention valve structure (100) of the present invention will be examined in detail with reference to the cross-sectional perspective view showing the leak prevention valve structure of a variable intake system according to one embodiment of the present invention in FIG. 4, the perspective view and front view showing the pivot shaft according to one embodiment of the present invention in FIG. 5, the perspective view showing the components of a detachable valve flap according to one embodiment of the present invention in FIG. 6, and the cross-sectional perspective view AA of the body of a detachable valve flap according to one embodiment of the present invention and the cross-sectional perspective view showing the combined state of the components in FIG. 7.

[0074] Referring to FIGS. 4 to 7, one or more through holes (192, 193, 194) are formed in the pivot shaft (190), and a coupling groove (1415) is formed inside the body (141) of the detachable valve flap (140). A spring (145) passes through the through hole (194) of the pivot shaft (190) and is inserted into the coupling groove (1415), thereby connecting the detachable valve flap (140) to the pivot shaft (190), and the detachable valve flap (140) receives an elastic force in a direction perpendicular to the axial direction of the pivot shaft (190) by the spring (145).

[0075] For convenience, only the detachable valve flap (140) that opens and closes the fourth intake passage is shown in FIGS. 6 and 7, but the valve flap (120) that opens and closes the second intake passage and the valve flap (130) that opens and closes the third intake passage shown in FIGS. 2, FIGS. 3 (a) and FIGS. 4, and the first valve flap (110') that opens and closes the first intake passage shown in FIGS. 3 (b) may also be detachable valve flaps having the same structure as the fourth valve flap (140), and the configurations of these detachable valve flaps are assigned reference numerals according to the same rules as the components of the detachable valve flap (140) shown in FIGS. 6. That is, just as the body (141), spring (145), valve cover (149), coupling groove (1415), etc. of the valve flap (140) that opens and closes the fourth intake passage are assigned with the reference numerals listed in parentheses, the body (121), spring (125), valve cover (129), coupling groove (1215), etc. of the valve flap (120) that opens and closes the second intake passage are also assigned in the same manner as the reference numerals listed in parentheses and are used in the following description.

[0077] As an embodiment of the present invention, a leak prevention valve structure (100) includes three (N-1) detachable valve flaps (120, 130, 140) that are detachably mounted on the pivot shaft (190) among four (where N is a positive integer 4) valve flaps as shown in FIG. 3 (a), and as shown in FIG. 4, three (N-1) through holes (192, 193, 194) are formed in the pivot shaft, and a coupling groove (1215, 1315, 1415) is formed inside the body (121, 131, 141) of the detachable valve flap (120, 130, 140), so that the detachable valve flap (120, 130, 140) passes through the through holes (192, 193, 194) of the pivot shaft (129). It is shown that the springs (125, 135, 145) are fitted and fixed in the coupling grooves (1215, 1315, 1415) of the 140, so that the three (N-1) detachable valve flaps (120, 130, 140) each receive an elastic force in a direction perpendicular to the axial direction of the rotation axis.

[0079] And here, as an embodiment of the present invention, the leak prevention valve structure (100) includes one integral valve flap (110) that is fixed integrally to a pivot shaft so as not to be detachably attached among the four (N) valve flaps, and as shown in FIG. 5, a fixing surface (191) for fixing the integral valve flap (110) is formed on the pivot shaft (190) at the position where the integral valve flap (110) is fixed, so that the integral valve flap (110) can be fixed.

[0081] And as another embodiment of the present invention, a leak-prevention valve structure (100') includes four (where N is a positive integer 4) detachable valve flaps (110', 120, 130, 140) that are detachably mounted on the pivot shaft (190) as shown in FIG. 3 (b); N through holes are formed in the pivot shaft (190); and coupling grooves (1115, 1215, 1315, 1415) are formed inside the body (111', 121, 131, 141) of the detachable valve flaps (110', 120, 130, 140); and springs (115, 125, 135, 145) are fitted and fixed in the coupling grooves of the valve flaps by passing through the through holes of the pivot shaft, thereby the N detachable valves All flaps (110', 120, 130, 140) may be configured to receive elastic force in a direction perpendicular to the axial direction of the rotation axis.

[0083] In addition, as an embodiment of the present invention, the leak prevention valve structure (100) may have a through hole (192, 193, 194) formed in the pivot shaft that has a cross-sectional shape that is slit-shaped, a coupling groove (1215, 1315, 1415) formed in the detachable valve flap (120, 130, 140) that has a cross-sectional shape that is slit-shaped, and the spring (125, 135, 145) may be a plate spring having a cross-sectional shape corresponding to the cross-sectional shape of the through hole and the coupling groove.

[0085] In addition, a plate spring (125, 135, 145) is fitted into the coupling groove (1215, 1315, 1415) of the detachable valve flap (120, 130, 140) by passing through the through hole (192, 193, 194) of the above-mentioned pivot shaft (190), and a valve cover (129, 139, 149) can be attached to the surface of the detachable valve flap (120, 130, 140) into which the plate spring (125, 135, 145) is inserted.

[0087] In addition, as shown in FIGS. 6 and 7, a pivot shaft insertion hole (1213, 1313, 1413) is formed in the body (121, 131, 141) of the detachable valve flap (120, 130, 140) to be fitted onto the pivot shaft (190), and a raised portion (1214, 1314, 1414) shaped to surround the inserted pivot shaft (190) is formed, and a recess (1219, 1319, 1419) is formed in the central lower part of the upper surface of the body (121, 131, 141) for the entry of the leaf spring (125, 135, 145) and the coupling of the valve cover (129, 139, 149), and the body (121, 131, In the central upper part of 141), the coupling groove (1215, 1315, 1415) is formed along the longitudinal direction of the detachable valve flap (120, 130, 140), so that the plate spring (125, 135, 145) can be fitted and coupled to the through hole (192, 193, 194) of the pivot shaft and the coupling groove (1215, 1315, 1415) of the detachable valve flap through the concave part (1219, 1319, 1419).

[0089] In addition, a circumferential wing portion (1212, 1312, 1412) having a thickness thinner than the central body portion is formed around the body (121, 131, 141) of the above-detachable valve flap (120, 130, 140), and an injection joint hole (1217, 1317, 1417) is formed in the circumferential wing portion so that the flexible circumferential portion (122, 132, 142) described later can be firmly and tightly joined.

[0091] And as shown in FIG. 8, a gap is formed between the inner surface of the coupling groove of the detachable valve flap and the outer surface of the plate spring as needed, and the gap can be set differently for each detachable valve flap in each intake passage.

[0092] In addition, as shown in FIG. 9, the entry angle of the through hole formed in the pivot shaft can be set differently for each detachable valve flap in each intake passage as needed.

[0093] In the case of FIG. 8, the gap inside the rightmost detachable valve flap located near the pivot arm (22) to which the driving force of the actuator (20) is transmitted is made the largest, and the gap is formed to gradually narrow as it goes toward the left detachable valve flap far from the pivot arm (gap C > gap B > gap A), thereby actively preventing the lifting phenomenon of the valve flap due to twisting of the pivot shaft.

[0094] Likewise, in the case of FIG. 9, the angle of entry of the through hole of the pivot shaft to which the rightmost detachable valve flap, located near the pivot arm (22) to which the driving force of the actuator (20) is transmitted, is made largest, and the angle of entry of the through hole is formed to gradually become smaller as it goes toward the left detachable valve flap, which is far from the pivot arm (angle C > angle B > angle A), thereby more actively preventing the lifting phenomenon of the valve flap due to twisting of the pivot shaft.

[0095] In addition, as shown in Fig. 9, if the through hole entry angle and gap are used together as needed, the lifting phenomenon can be prevented over a wider range.

[0097] In addition, the detachable valve flap (120, 130, 140) according to the embodiment of the present invention described above may be composed of a rigid body part (121, 131, 141) and a flexible periphery part (122, 132, 142) as shown in FIG. 6, and the integrated valve flap (110) may also be composed of a rigid body part (111) and a flexible periphery part (112). Here, the rigid body part may be made of plastic material, and the flexible periphery part may be made of rubber or an elastic plastic material.

[0099] In addition, as shown in FIG. 10 (a), which shows the open state of the valve flap of a variable intake system equipped with a leak prevention valve structure of a variable intake system according to an embodiment of the present invention, and FIG. 10 (b), which shows the closed state, the leak prevention valve structure of a variable intake system according to an embodiment of the present invention restricts the movement of the detachable valve flaps (120, 130, 140) by means of a stopper (17) protruding from the inner wall of each intake passage, thereby allowing the position of the detachable valve flaps when they are fully opened to be specified.

[0101] Next, FIG. 11 is an overall process diagram showing a method for assembling a leak-prevention valve structure of a variable intake system according to an embodiment of the present invention, and FIG. 12 is a second process diagram showing a method for assembling a leak-prevention valve structure of a variable intake system according to an embodiment of the present invention.

[0103] Referring to FIG. 11 and FIG. 12, a method for assembling a leak-prevention valve structure of a variable intake system according to another embodiment of the present invention may include the steps of machining a pivot shaft having a plurality of through holes (s100), inserting a detachable valve flap into the pivot shaft (s400), and inserting a spring into the pivot shaft and the detachable valve flap (s500).

[0105] And following the step of machining the pivot shaft (s100), the method may further include the step of injecting an integral valve flap as a plastic insert onto the pivot shaft (s200) and the step of molding the circumference of the integral valve flap with a flexible material (s300).

[0107] Additionally, following the step (s500) of inserting a spring into the pivot shaft and the detachable valve flap, the method may further include the step (s600) of joining the valve cover.

[0109] The above detailed description of the present invention describes only specific embodiments thereof. However, it should be understood that the present invention is not limited to the specific forms mentioned in the detailed description, but rather should be understood to include all variations, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. Explanation of the symbols

[0111] 10: Intake manifold 11: First intake passage 12: Second intake passage 13: Third intake passage 14: 4th intake passage 17: Stopper 19: Bearing 20: Actuator 21: Linkbar 22: Hoedongam 100: Structure of the leak-proof valve in a variable intake system 110: Integrated valve flap 111: Integrated valve flap body or rigid body part 110', 120, 130, 140: Removable valve flap 111', 121, 131, 141: Detachable valve flap body or rigid body part 1211, 1311, 1411: Top surface of the detachable valve flap body 1212, 1312, 1412: Circumference wing portion 1213, 1313, 1413: Rotation shaft insertion hole 1214, 1314, 1414: Uplift 1215, 1315, 1415: Connecting groove 1217, 1317, 1417: Injection joint hole 1219, 1319, 1419: Concave part 112, 112', 122, 132, 142: Flexible perimeter 1421: Flexible perimeter body 1422: Circumference wing insertion groove 1423: Rotation shaft insertion hole 115', 125, 135, 145: Spring 119, 129, 139, 149: Valve cover 190: Rotation axis 191: Fixed surface 192, 193, 194: Penetrating hole 195: Joining surface

Claims

Claim 1 A leak prevention valve structure of a variable intake system, which is mounted on a variable intake system having N intake passages, comprising a pivot shaft equipped with valve flaps that open and close the N intake passages, and at least one detachable valve flap among the N valve flaps that is detachably mounted on the pivot shaft, wherein one or more through holes are formed in the pivot shaft, and a coupling groove is formed inside the body of the detachable valve flap, wherein a spring passes through the through hole of the pivot shaft and is inserted into the coupling groove so as to connect the detachable valve flap to the pivot shaft, and wherein the detachable valve flap receives an elastic force in a direction perpendicular to the axial direction of the pivot shaft by means of the spring. Claim 2 A leak prevention valve structure of a variable intake system according to claim 1, comprising N-1 detachable valve flaps among the N valve flaps that are detachably mounted on the pivot shaft, wherein N-1 through holes are formed in the pivot shaft and a coupling groove is formed inside the body of the detachable valve flap, and a spring is fitted and fixed in the coupling groove of the detachable valve flap by passing through the through holes of the pivot shaft, so that the N-1 detachable valve flaps receive an elastic force in a direction perpendicular to the axial direction of the pivot shaft. Claim 3 In paragraph 2, the leak prevention valve structure of a variable intake system is characterized by including one integral valve flap among the N valve flaps that is integrally fixed to a pivot shaft so as not to be detachably attached, and a fixing surface for fixing the integral valve flap is formed on the pivot shaft at the position where the integral valve flap is fixed, thereby fixing the integral valve flap. Claim 4 A leak prevention valve structure of a variable intake system according to claim 1, comprising N detachable valve flaps detachably mounted on the pivot shaft, wherein N through holes are formed in the pivot shaft and a coupling groove is formed inside the body of the detachable valve flap, and wherein a spring is fitted and fixed in the coupling groove of the valve flap by passing through the through holes of the pivot shaft, so that the N detachable valve flaps receive an elastic force in a direction perpendicular to the axial direction of the pivot shaft. Claim 5 A leak prevention valve structure of a variable intake system, characterized in that, in any one of claims 1 to 4, the through hole formed in the pivot shaft has a cross-sectional shape that is slit-shaped, the coupling groove formed in the detachable valve flap has a cross-sectional shape that is slit-shaped, and the spring is a plate spring having a cross-sectional shape corresponding to the cross-sectional shapes of the through hole and the coupling groove. Claim 6 In claim 5, the leak-prevention valve structure of a variable intake system is characterized in that a leaf spring is fitted into the coupling groove of the detachable valve flap by passing through the through hole of the pivot shaft, and a valve cover is attached to the surface of the detachable valve flap where the leaf spring is inserted. Claim 7 In claim 6, the body of the detachable valve flap has a pivot shaft insertion hole formed therein for fitting into the pivot shaft, and a raised portion formed therein that surrounds the inserted pivot shaft; a recess formed at the lower center of the upper surface of the body for the entry of the leaf spring and the coupling of the valve cover; and a coupling groove formed inside the upper center of the body along the longitudinal direction of the detachable valve flap, wherein the leaf spring is fitted into the through hole of the pivot shaft and the coupling groove of the detachable valve flap through the recess. Claim 8 In claim 7, a gap is formed between the inner surface of the coupling groove of the detachable valve flap and the outer surface of the plate spring, and the gap is set differently for each detachable valve flap in each intake passage, characterized in that the leak-prevention valve structure of a variable intake system Claim 9 In claim 7, the leakage prevention valve structure of a variable intake system is characterized by setting the entry angle of the through hole formed in the pivot shaft differently for each detachable valve flap in each intake passage. Claim 10 In claim 1, the leak-prevention valve structure of a variable intake system is characterized in that the detachable valve flap is composed of a rigid body portion and a flexible perimeter portion. Claim 11 In paragraph 3, the leakage prevention valve structure of a variable intake system is characterized in that the integrated valve flap is composed of a rigid body portion and a flexible perimeter portion. Claim 12 A leak-prevention valve structure of a variable intake system, characterized in that, in either claim 10 or 11, the rigid body portion is made of plastic material and the flexible perimeter portion is made of rubber or elastic plastic material. Claim 13 A leak prevention valve structure of a variable intake system according to claim 1 is characterized in that the movement of the detachable valve flap is restricted by a stopper protruding from the inner wall of each intake passage, thereby specifying the position when the detachable valve flap is fully open. Claim 14 A method for assembling a leak-prevention valve structure of a variable intake system described in claim 1, comprising the steps of: machining a pivot shaft having a plurality of through holes; inserting a detachable valve flap into the pivot shaft; and inserting a spring into the pivot shaft and the detachable valve flap. Claim 15 In claim 14, a method for assembling a leak-prevention valve structure of a variable intake system further comprising, after the step of machining the pivot shaft, the step of injecting an integral valve flap as a plastic insert onto the pivot shaft; and the step of molding the periphery of the integral valve flap with a flexible material. Claim 16 In claim 14, a method for assembling a leak-prevention valve structure of a variable intake system further comprising the step of joining a valve cover following the step of inserting a spring into the pivot shaft and the detachable valve flap.

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