Valve device

Abstract

To provide a valve device capable of easily mounting a valve element and improving durability.SOLUTION: A first check valve 7 is a valve device for opening and closing a suction side communication path 20 of fluid, and includes a pump body having a partition wall 3a where the suction side communication path 20 and a projection 35 are formed, and a flexible material formed in a plate shape having an insertion hole. And the push nut 30 that is formed in a disk shape smaller than the valving element 7a portion, has a hole into which the projection portion 35 is inserted in a central portion, and is locked to the projection portion 35 locking the valving element 7a portion to prevent the valving element 7a portion from coming off from the projection portion 35, in which an outer peripheral end portion 45 of the push nut 30 in contact with the valving element 7a portion is formed in a curved surface shape. 7a.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a valve device that opens and closes a fluid passage. [Background technology]

[0002] 2. Description of the Related Art Various types of valve devices that open and close fluid passages are known, such as check valves used in engine fuel pumps and the like.

[0003] For example, the check valve of a fuel pump described in Patent Document 1 is provided at the opening of a communication passage that connects two chambers and through which fuel passes, and includes a valve element made of a circular plate-shaped flexible material such as a resin film. The valve element is supported at its center and is swingable at its outer periphery. The valve element is also structured to open and close multiple openings arranged concentrically around the support portion. A valve seat is provided around the opening, protruding toward the valve element. When the pressure on one of the two sides of the valve element opposite the communication passage becomes greater than the pressure on the communication passage side, the valve element and the valve seat come into contact to close the opening. On the other hand, when the pressure on the communication passage side of the valve element becomes greater than the pressure on the opposite side of the communication passage, the valve element and the valve seat separate to open the opening. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-78288 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, the valve element is supported by inserting and fixing a grommet into a hole in the pump body. Therefore, to prevent the grommet from slipping out of the hole in the pump body, it is necessary to provide a return portion at the tip of the grommet, for example. This makes it difficult to assemble the grommet to the pump body, and increases the number of assembly steps.

[0006] Alternatively, a protrusion may be provided on the pump body, the valve element may be supported on the protrusion, and the tip of the protrusion may be crimped to support the valve element on the pump body. However, this also has the problem of increasing the number of assembly steps required for crimping.

[0007] Furthermore, since the valve element moves frequently during opening and closing operations, it is necessary to ensure durability at the contact points of the support portion.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a valve device in which the valve body can be easily attached and which has improved durability. [Means for solving the problem]

[0009] In order to achieve the above object, the valve device of the present invention is a valve device that opens and closes a fluid passage, and comprises: a housing having a wall member in which the passage and a convex portion are formed; a valve element formed in a plate shape from a flexible material and having a first hole portion, into which the convex portion is inserted and supported by the convex portion to open and close the passage; and a push nut formed in a circular plate shape smaller than the valve element, having a second hole portion in the center into which the convex portion is inserted, and being engaged with the convex portion to prevent the valve element from coming off the convex portion, wherein the outer peripheral end of the push nut that comes into contact with the valve element is formed in a curved shape. [Effects of the Invention]

[0010] According to the valve device of the present invention, the valve body can be easily assembled to the housing by inserting the convex portion into the first hole portion of the valve body to support the valve body on the convex portion of the housing and engaging the push nut with the convex portion.

[0011] Furthermore, since the outer peripheral end of the push nut that comes into contact with the valve body is formed into a curved surface, even if the outer peripheral end of the push nut comes into contact with the valve body when the valve body is opened or closed, the valve body is less likely to be damaged, and the durability of the valve body, i.e., the durability of the valve device, can be improved. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an external view of a fuel pump employing a valve device according to the present invention; [Figure 2] 1 is a vertical cross-sectional view showing the structure of a fuel pump employing a valve device according to the present invention; [Figure 3] FIG. 2 is a vertical cross-sectional view showing a fuel intake state of the fuel pump according to the embodiment. [Figure 4] FIG. 2 is a vertical cross-sectional view showing a fuel discharge state of the fuel pump according to the embodiment. [Figure 5] FIG. 2 is a top view of a pump body equipped with a first check valve and a second check valve according to the present embodiment. [Figure 6] FIG. 2 is an assembly diagram of the first check valve of the present embodiment. [Figure 7] FIG. 2 is a perspective view showing the appearance of a push nut. [Figure 8] FIG. 4 is a vertical cross-sectional view showing the cross-sectional shape of the first check valve when the valve is closed. [Figure 9] FIG. 4 is a vertical cross-sectional view showing the cross-sectional shape of the first check valve when the valve is open. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] Fig. 1 is an external view of a fuel pump 1 employing a valve device of the present invention. Fig. 2 is a vertical cross-sectional view showing the structure of the fuel pump. Fig. 2 shows a cross section of the AA portion shown in Fig. 1.

[0015] As shown in FIGS. 1 and 2, a fuel pump 1 according to this embodiment is a diaphragm type fuel pump having a diaphragm 2, and supplies fuel from a fuel tank to a fuel supply system of an engine.

[0016] The fuel pump 1 includes a pump body 3, a bottom body 4, a cover 5, a diaphragm 2, a membrane 6, a first check valve 7, and a second check valve 8. The first check valve 7 and the second check valve 8 are check valves and correspond to the valve device of the present invention. The pump body 3, the bottom body 4, and the cover 5 correspond to the housing of the present invention.

[0017] The pump body 3, bottom body 4, and cover 5 are made of, for example, resin. The pump body 3 is formed in a generally cylindrical shape with an internal partition wall 3a (wall member) and both side surfaces open. The bottom body 4 is fixed to one side surface of the pump body 3 and seals that side surface. The cover 5 is fixed to the other side surface of the pump body 3 and seals that side surface.

[0018] The diaphragm 2 and the membrane 6 are formed into a thin, disk-like shape from, for example, NBR rubber. The diaphragm 2 is sandwiched between the pump body 3 and the bottom body 4. The membrane 6 is sandwiched between the pump body 3 and the cover 5.

[0019] A pump chamber 9 is formed between the diaphragm 2 and the partition wall 3a of the pump body 3. A pulse chamber 10 is formed between the diaphragm 2 and the bottom body 4. That is, the diaphragm 2 separates the pump chamber 9 from the pulse chamber 10. A pulse inlet 11 is formed in the bottom body 4 for introducing pressure into the pulse chamber 10, and pulsating pulse pressure of intake air or the like is introduced into the pulse chamber 10 from an intake manifold or crank chamber of the engine (not shown) via the pulse inlet 11.

[0020] A spring 28 is provided in the pulse chamber 10 to bias the diaphragm 2. The spring 28 biases the diaphragm 2 toward the pump chamber 9 with respect to the bottom body 4.

[0021] A fuel suction chamber 12 and a fuel discharge chamber 13 are formed between the membrane 6 and the partition wall 3a of the pump body 3. A suction-side damper chamber 14 facing the fuel suction chamber 12 across the membrane 6, and a discharge-side damper chamber 15 facing the fuel discharge chamber 13 across the membrane 6 are formed between the membrane 6 and the cover 5. In other words, the membrane 6 separates the fuel suction chamber 12 from the suction-side damper chamber 14, and also separates the fuel discharge chamber 13 from the discharge-side damper chamber 15.

[0022] The pump body 3 is provided with an intake port 16 communicating with the fuel intake chamber 12 and a discharge port 17 communicating with the fuel discharge chamber 13. The intake port 16 is connected to a fuel tank (not shown), and the discharge port 17 is connected to a fuel injection device of the engine or the like.

[0023] A suction-side communication passage 20 that connects the fuel suction chamber 12 and the pump chamber 9, and a discharge-side communication passage 21 that connects the pump chamber 9 and the fuel discharge chamber 13 are formed in the partition wall 3a of the pump body 3. The suction-side communication passage 20 and the discharge-side communication passage 21 correspond to the passages of the present invention.

[0024] The first check valve 7 is provided on the partition wall 3a of the pump body 3 and has the function of opening and closing the suction side communication passage 20. The first check valve 7 has the function of allowing fuel to pass only from the fuel suction chamber 12 to the pump chamber 9.

[0025] The second check valve 8 is provided on the partition wall 3a of the pump body 3 and has the function of opening and closing the discharge-side communication passage 21. The second check valve 8 has the function of allowing fuel to pass only from the pump chamber 9 to the fuel discharge chamber 13.

[0026] Fig. 3 is a vertical cross-sectional view showing a fuel intake state in the fuel pump 1. Fig. 4 is a vertical cross-sectional view showing a fuel discharge state in the fuel pump 1.

[0027] In fuel pump 1 configured as described above, when the engine is operating and pulse pressure is introduced into pulse chamber 10, creating a negative pressure inside pulse chamber 10, diaphragm 2 moves toward bottom body 4, or to the right in FIG. 3, against the bias of spring 28, as shown in FIG. 3. This creates a negative pressure in pump chamber 9, opening first check valve 7 and closing second check valve 8, allowing fuel to move from fuel suction chamber 12 to pump chamber 9.

[0028] When the pressure inside the pulse chamber 10 becomes positive, the diaphragm 2 moves away from the bottom body 4, that is, to the left in FIG. 4, as shown in FIG. 4. This causes the pump chamber 9 to become positive pressure, the first check valve 7 closes, and the second check valve 8 opens, allowing fuel to move from the pump chamber 9 to the fuel discharge chamber 13. Note that the diaphragm 2 is biased toward the pump chamber 9 by the spring 28, which encourages the movement of the diaphragm 2 when the pressure inside the pulse chamber 10 switches from negative to positive, thereby facilitating the movement of fuel from the pump chamber 9 to the fuel discharge chamber 13.

[0029] When a pulse pressure, which alternates between positive and negative pressure, is supplied from the engine into the pulse chamber 10, the diaphragm 2 shown in Figures 3 and 4 repeatedly moves, and fuel is drawn in through the intake port 16 and discharged through the discharge port 17.

[0030] The membrane 6 reduces sudden fluctuations in pressure in the fuel suction chamber 12 and the fuel discharge chamber 13. Therefore, fuel is discharged from the fuel discharge chamber 13 of the fuel pump 1 in a stable manner.

[0031] Next, the first check valve 7 will be described in detail with reference to FIGS.

[0032] FIG. 5 is a top view of the pump body 3 equipped with the first check valve 7 and the second check valve 8. FIG. 6 is an assembly diagram of the first check valve 7. FIG. 7 is a perspective view showing the shape of the push nut 30. FIG. 8 is a vertical cross-sectional view showing the cross-sectional shape of the first check valve 7 when the valve is closed. FIG. 9 is a vertical cross-sectional view showing the cross-sectional shape of the first check valve 7 when the valve is open. Note that FIG. 5 is a view of the first check valve 7 and the second check valve 8 provided in the pump body 3 as seen from the pump chamber 9 side. FIGS. 8 and 9 are cross-sectional views of the BB portion shown in FIG. 5. The arrows in FIG. 9 indicate the direction of fuel movement.

[0033] 5 and 6, the first check valve 7 provided in the partition wall 3a has a flexible, circular, thin plate-like valve element 7a. The valve element 7a is composed of a thin plate-like first valve element 31 made of NBR and a thin plate-like second valve element 32 made of PET, stacked together.

[0034] 5, 6, 8, and 9, the partition wall 3a has a cylindrical protrusion 35 that protrudes toward the pump chamber 9 to support the first valve body 31 and the second valve body 32. A plurality of suction side communication passages 20 are provided in the partition wall 3a, concentrically arranged at intervals in the circumferential direction around the protrusion 35. A valve seat 7b that protrudes in an annular shape and whose upper surface serves as a seat is provided on the wall surface of the partition wall 3a on the pump chamber 9 side, outside the suction side communication passages 20. The openings of all of the suction side communication passages 20 and the valve seat 7b are covered by the valve bodies 7a.

[0035] The first valve body 31 and the second valve body 32 are provided at their centers with circular insertion holes 37 into which the protrusions 35 are inserted. The protrusions 35 are inserted into the insertion holes 37 in the order of the first valve body 31 and the second valve body 32 from the partition wall 3a side, and then the push nut 30 is inserted and fixed to the protrusions 35, thereby sandwiching and supporting the first valve body 31 and the second valve body 32 between the partition wall 3a and the push nut 30.

[0036] The push nut 30 is made of, for example, SUS.

[0037] As shown in Figure 7, the push nut 30 has a hole 40 larger than the protrusion 35 in its disk-shaped center so that the protrusion 35 can be inserted therein, and three claws 43 extending from the inside of an annular outer periphery 41 toward the center. The claws 43 have a circumferential width of about several millimeters and are arranged at equal intervals around the outer periphery 41. The radially inner end faces of the claws 43 come into contact with the outer periphery of the protrusion 35 and are engaged with the protrusion 35.

[0038] The claws 43 of the push nut 30 are inclined at several degrees toward one side surface. The outer peripheral portion 41 of the push nut 30 has an outer peripheral edge 45 on the other side surface that is chamfered or bent in an arc shape all around. In other words, the corners of the outer peripheral edge on the other side surface of the push nut 30 are rounded in an arc shape.

[0039] As shown in FIG. 6, when the push nut 30 supports the first valve body 31 and the second valve body 32 with the protrusions 35 inserted therein, the push nut 30 is inserted into the protrusions 35 from the other side surface side.

[0040] As shown in Figures 8 and 9, the tip of the protrusion 35 is provided with a protrusion 35a that protrudes slightly radially outward. The protrusion 35a may be formed, for example, by having the tip of the protrusion 35 protrude radially outward in a portion of the circumference, or by having the outer diameter of the tip of the protrusion 35 slightly larger over the entire circumference. After the first valve body 31 and the second valve body 32 are attached to the protrusion 35, when the protrusion 35 is inserted into the hole 40 of the push nut 30, the claw 43 comes into contact with the tip of the protrusion 35 and bends toward one side. When the tip of the protrusion 35 passes the claw 43, the claw 43 returns to its original bending state and is engaged with the protrusion 35a of the protrusion 35. As a result, the push nut 30 presses and supports the first valve body 31 and the second valve body 32, preventing the valve body 7a (the first valve body 31 and the second valve body 32) from slipping out of the protrusion 35. When the protrusions 35a are configured to protrude radially outward in part of the circumferential direction of the convex portion 35, the circumferential width and spacing of the protrusions 35a may be set so that at least part of the claws 43 are engaged with the protrusions 35a. Even if the protrusions 35a are not present, if the claws 43 are configured to bite into the convex portions 35, the push nut 30 will be engaged with the convex portions 35 and the function of preventing the valve body 7a from coming off can be obtained, but the presence of the protrusions 35a makes it even more difficult for the push nut 30 to come off.

[0041] The second check valve 8 also has a protrusion 35 and a valve element 8a shaped similarly to the protrusion 35 and valve element 7a of the first check valve 7. Like the valve element 7a, the valve element 8a is supported by the protrusion 35 and prevented from coming off by a push nut 30. Like the suction side communication passage 20, a plurality of discharge side communication passages 21 are provided concentrically at intervals in the circumferential direction around the protrusion 35. However, the second check valve 8 differs in that the valve element 8a and valve seat are not provided on the pump chamber 9 side, but on the fuel discharge chamber 13 side opposite the pump chamber 9.

[0042] 8, in first check valve 7, when the pressure in pump chamber 9 is higher than that in fuel suction chamber 12, the outer periphery of valve element 7a abuts against valve seat 7b on partition wall 3a. As a result, valve element 7a closes the openings of all suction-side communication passages 20, preventing fuel from flowing from pump chamber 9 into fuel suction chamber 12.

[0043] 9, when the pressure in the fuel suction chamber 12 is higher than that in the pump chamber 9, the outer periphery of the valve element 7a bends toward the pump chamber 9. This causes the outer periphery of the valve element 7a to move away from the valve seat 7b. Therefore, the fuel in the fuel suction chamber 12 flows from the suction-side communication passage 20 through the gap between the valve element 7a and the valve seat 7b and into the pump chamber 9.

[0044] As described above, the first check valve 7 provided in the fuel pump 1 of this embodiment is a valve device that opens and closes the suction-side communication passage 20 provided in the partition wall 3a with the valve element 7a, and the partition wall 3a is provided with a convex portion 35 in a position near the suction-side communication passage 20. The first valve element 31 made of rubber and the second valve element 32 made of a PET material are engaged with the convex portion 35 as the valve element 7a, and the push nut 30 is further engaged with the convex portion 35 to prevent the valve element 7a from coming off.

[0045] In this way, by inserting the valve body 7a and the push nut 30 into the protrusion 35, the valve body 7a can be easily engaged with the protrusion 35, thereby reducing the number of steps required to assemble the first check valve 7.

[0046] Furthermore, the push nut 30 has a circular disk shape, but the outer peripheral edge that comes into contact with the valve element 7a is curved. When the valve element 7a opens, it bends toward the push nut 30 and comes into contact with the outer peripheral edge of the push nut 30. Therefore, by making the outer peripheral edge of the push nut 30 curved, the valve element 7a that comes into contact with it is protected, and the durability of the valve element 7a can be ensured.

[0047] The push nut 30 has an annular plate-shaped outer peripheral portion 41 having a hole 40 in the center that is larger than the protrusion 35, and claw portions 43 extending from the inner surface of the outer peripheral portion 41 toward the center, and the tips of the claw portions 43 come into contact with the outer peripheral surface of the protrusion 35 and are engaged with the protrusion 35, so that the push nut 30 can be configured with a simple and compact structure and can be easily engaged with the protrusion 35.

[0048] In particular, it becomes possible to form the push nut 30 from a thin plate, which reduces the length by which the protrusion 35 protrudes into the pump chamber 9. Therefore, it is not necessary to increase the width of the pump chamber 9 so as not to contact the diaphragm 2 disposed within the pump chamber 9, and the fuel pump 1 can be configured compactly.

[0049] The claw portion 43 extends from the inner surface of the outer peripheral portion 41 toward the center, slanting in the axial direction. By inserting the convex portion 35 into the hole 40 of the push nut 30 in a direction such that the claw portion 43 is slanted toward the protruding direction of the convex portion 35, the tip of the claw portion 43 comes into contact with the tip of the convex portion 35 and easily flexes and is inserted to lock the push nut 30, and the push nut 30 locked to the convex portion 35 is less likely to come loose.

[0050] The tip of the convex portion 35 is provided with a protruding portion 35a that protrudes radially outward, so that the claw portion 43 of the push nut 30 can be securely locked onto the neck portion of the protruding portion 35a.

[0051] Since the protrusion 35a protrudes radially outward around the entire circumference of the convex portion 35, the claw portion 43 of the push nut 30 can be engaged with the protrusion 35a regardless of the circumferential position of the push nut 30 relative to the convex portion 35.

[0052] The push nut 30 is provided with three claws 43 at equal intervals in the circumferential direction of the outer circumferential portion 41. This allows the claws 43 to adequately secure the function of preventing the push nut 30 from coming loose, while reducing the number of claws 43 and reducing the manufacturing cost of the push nut 30. The number of claws 43 may be any number other than three. While one claw 43 may be provided, multiple claws are preferable in terms of the locking ability of the push nut 30.

[0053] Although the description of the embodiment is now complete, aspects of the present invention are not limited to the above embodiment. For example, the above embodiment describes the configuration of the first check valve 7, but the second check valve 8 may also be configured to have the valve element 8a retained by the push nut 30.

[0054] Furthermore, in this embodiment, the present invention is applied to the first check valve 7 that controls the flow of fuel, but the present invention can also be applied to a check valve that controls the flow of fluids other than fuel.

[0055] The present invention may also be applied to check valves used in devices other than fuel pumps. In addition, the present invention may be widely applied to valve devices other than check valves, which have a structure in which a flexible valve element is tightly attached to a valve seat to close the valve. [Explanation of symbols]

[0056] 1 fuel pump 3 Pump body (housing) 3a Partition wall (wall member) 4 Bottom body (casing) 5 Cover (housing) 7. First check valve (valve device) 7a Valve body 8 Second check valve (valve device) 20 Intake side connecting passage (passage) 21 Discharge side connecting passage (passage) 30 Push Nut 35 Convex part 35a Protrusion 37 Insertion hole (first hole) 40 holes (second hole) 41 Outer periphery (main body) 43 Claw 45 Outer edge

Claims

1. A valve device for opening and closing a fluid passage, a housing having a wall member in which the passage and the protrusion are formed; a valve element formed of a flexible material in a plate shape having a first hole, the protrusion being inserted into the first hole and supported by the protrusion to open and close the passage; a push nut formed in a disk shape smaller than the valve body, having a second hole in the center into which the protrusion is inserted, and being engaged with the protrusion to prevent the valve body from slipping out of the protrusion, The outer peripheral end of the push nut that comes into contact with the valve body is formed into a curved surface. A valve device characterized by:

2. The push nut is a main body portion in the shape of an annular plate having the second hole portion larger than the protrusion portion at the center thereof; a claw portion extending from the inner surface of the main body portion toward the center thereof and inclining in the axial direction, The tip of the claw portion comes into contact with the outer circumferential surface of the protrusion and is engaged with the protrusion.

2. The valve device according to claim 1.

3. a protrusion protruding radially outward at a tip of the convex portion; The claw portion of the push nut is engaged with the protrusion.

3. The valve device according to claim 2.

4. The protruding portion protrudes radially outward around the entire circumference of the convex portion.

4. The valve device according to claim 3.

5. The claws are provided in a plurality at equal intervals in the circumferential direction of the main body.

3. The valve device according to claim 2.

6. The valve device is provided in a fuel pump, and the fluid is fuel.

2. The valve device according to claim 1.

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