Valve device

Abstract

Provided is a valve device capable of preventing leakage of coolant.　A valve device 1 according to the present invention comprises: a housing 11 in which a coolant inlet 11a, a coolant outlet 11b, and an internal space 11c are formed; a valve body 12 that is accommodated in the internal space 11c and rotates around a rotation axis; a shaft 13 positioned on the rotation axis; a seal member 15 that is attached to the inlet 11a or the outlet 11b and is in sliding contact with the outer periphery of the valve body 12; and a drive device that rotationally drives the valve body 12. The valve body 12 includes an inner cylinder 12a, an outer cylinder 12b disposed on the outer periphery of the inner cylinder 12a, and a connection end part 12c connecting the inner cylinder 12a and the outer cylinder 12b. Moreover, a valve hole 12e capable of providing communication between a valve body space 12d and the inflow port 11a or the outflow port 11b is formed in the outer cylinder 12b, and a rib 12g having a height not reaching the outer periphery of the inner cylinder 12a is formed on the inner periphery of the outer cylinder 12b.

Description

Valve device

[0001] The present invention relates to a valve device.

[0002] 2. Description of the Related Art A cooling circuit for cooling an automobile engine uses a valve device for distributing coolant to various devices such as a radiator, an oil cooler, and an air conditioning heat exchanger.

[0003] For example, the valve device disclosed in Patent Document 1 includes a housing, a valve element rotatably accommodated in the housing, a shaft attached to the rotation axis of the valve element, a seal member in sliding contact with the outer periphery of the valve element, and a drive unit for rotating the valve element. The valve element has an inner cylinder attached to the outer periphery of the shaft, an outer cylinder disposed at a predetermined distance from the inner cylinder, and a connecting portion connecting the inner cylinder and the outer cylinder.

[0004] JP 2017-133622 A

[0005] The valve body is often made of synthetic resin and formed by injection molding. Although injection molding can easily produce a resin molded product, the shape of the resin molded product, variations in temperature and pressure within the mold, and the way the resin flows can cause deformation defects such as warping and sink marks in the resin molded product.

[0006] In conventional valve bodies, warping of the outer cylinder can be suppressed at the connection part, but sink marks can occur on the outer periphery of the part where the connection part connects to the outer cylinder. Depending on the location and extent of the sink marks, gaps can form between the outer cylinder and the seal member, which can cause coolant to leak.

[0007] The present invention has been made in view of the above-mentioned problems, and has an object to provide a valve device that can suppress leakage of coolant.

[0008] The valve device according to the present invention comprises a housing having an inlet and an outlet for a coolant and an internal space communicating with the inlet and the outlet, a valve element accommodated in the internal space and rotatable about a rotation axis for switching communication between the inlet and the outlet by rotation, a shaft positioned on the rotation axis, a seal member attached to the inlet or the outlet and in sliding contact with the outer periphery of the valve element, and a drive unit for rotating the valve element. The valve element has an inner tube, an outer tube disposed on the outer periphery of the inner tube, and a connecting end portion connecting one axial end of the inner tube and the outer tube, wherein an inner space is formed between the inner tube and the outer tube, a valve hole is formed in the outer tube for communicating the inner space with the inlet or the outlet, and a lattice-shaped portion is formed on the inner periphery of the outer tube so as not to reach the outer periphery of the inner tube.

[0009] According to the valve device of the present invention, a lattice-shaped portion is formed on the inner periphery of the outer cylinder, which prevents warping of the outer cylinder. Furthermore, the height of the lattice-shaped portion is set so that it does not reach the outer periphery of the inner cylinder, which prevents sink marks from forming on the outer periphery of the outer cylinder. This prevents gaps from forming between the valve body and the seal member due to molding defects, thereby preventing coolant leakage.

[0010] In the valve device according to the present invention, the grid-shaped portion may be formed of ribs or grooves, and the height of the ribs or the depth of the grooves may be 1 mm or less. This reliably prevents sink marks from forming on the outer periphery of the outer cylinder and prevents leakage of the coolant.

[0011] In the valve device according to the present invention, the lattice-shaped portion may extend to the periphery of the valve hole, thereby suppressing deformation of the periphery of the valve hole and efficiently suppressing leakage of the coolant.

[0012] According to the valve device of the present invention, leakage of the coolant can be suppressed.

[0013] Fig. 1 is a vertical cross-sectional view showing a valve device according to an embodiment, Fig. 2(a) is a front view of the valve body shown in Fig. 1, and Fig. 2(b) is a perspective view of the valve body shown in (a).

[0014] Hereinafter, an embodiment of a valve device according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to this embodiment. Furthermore, in the specification and drawings of the present application, elements that can be similarly described will be given the same reference numerals, and duplicated explanations may be omitted.

[0015] 1 is a vertical cross-sectional view showing a valve device according to one embodiment of the present invention. In this embodiment, for the sake of convenience, the upper and lower sides in FIG. 1 will be simply referred to as "upper" and "lower".

[0016] The valve device 1 of this embodiment is used in an automobile cooling circuit (coolant circulation system) that includes a cooling passage through which coolant flowing out of the engine (cylinder head side) returns to the engine (cylinder block side) via a radiator, and a bypass passage through which coolant flowing out of the engine returns to the engine via devices such as a heater and a battery without passing through the radiator. The valve device 1 of this embodiment discharges coolant supplied from the cylinder head side by pressurizing it with a water pump into the cooling passage or the bypass passage, and controls the flow rate.

[0017] As shown in FIG. 1, the valve device 1 of this embodiment includes a housing 11 having a cooling water inlet 11a, an outlet 11b, and an internal space 11c communicating with the inlet 11a and the outlet 11b, a valve element 12 accommodated in the internal space 11c of the housing 11 and rotatable about an axis (rotation axis) in the internal space 11c, a shaft 13 positioned on the rotation axis, an adapter 14 connected to the outlet 11b, a sealing member 15 attached to the inlet 11a or the outlet 11b and in sliding contact with the outer periphery of the valve element 12, a reducer 16, a case 17 with a bottom that forms a reducer accommodating space 17a on the upper side of the housing 11 for accommodating the reducer 16, and a lid 18 that covers the upper opening of the case 17 and closes the reducer accommodating space 17a. The valve device 1 controls the rotation of the valve element 12 in response to instructions from a control device (not shown) mounted on the vehicle, and opens and closes the passage of the cooling water from the inlet 11 a to the outlet 11 b, thereby appropriately discharging the cooling water supplied from the cylinder head side to the cooling passage or the bypass passage. The control device (not shown) may be provided within the valve device 1 as a control unit.

[0018] The structure of the valve device 1 of this embodiment will be described in more detail below. In this embodiment, the direction along the axis that is the center of rotation of the valve body 12 is referred to as the "axial direction," the direction perpendicular to the axis is referred to as the "radial direction," and the direction around the axis is referred to as the "circumferential direction."

[0019] In the valve device 1 of this embodiment, the housing 11 has an internal space 11c for accommodating the valve element 12. Furthermore, the upper part of the housing 11 and the lower part of the case 17 are provided with insertion cylindrical portions (11d, 17b) having a through hole formed therein for inserting the shaft 13. The lower opening of the housing 11 is closed, and a valve element support portion 19 having a bottomed cylindrical bearing portion 19a formed in the center thereof for supporting the lower end of the shaft 13 is attached and fixed to the housing 11.

[0020] The housing 11 is also provided with a coolant inlet 11a and outlet 11b. The inlet 11a and outlet 11b protrude outward from the outer periphery of the housing 11 and each communicate with an internal space 11c. An adapter 14 is attached to the outlet 11b. The adapter 14 communicates with the cooling path or a bypass path.

[0021] The reducer 16 housed in the reducer housing space 17a has a plurality of gears and reduces the rotation of the motor 20 before transmitting it to the valve element 12. The motor 20 operates in response to a command from a control device. In this embodiment, the reducer 16 and the motor 20 constitute a drive device that rotates and drives the valve element 12. Note that if the control device is provided as a control unit within the valve device 1, the control unit may also be included as part of the configuration of the drive device.

[0022] Valve element 12 has an outer cylinder 12b that can switch between a communication state with the cooling passage and a bypass passage, and rotates integrally with shaft 13. Shaft 13 is rotatably supported by bearings 17c and 19a provided in the center of the lower part of case 17. A gear as a component of speed reducer 16 is attached to shaft 13. When the gear rotates due to the drive of motor 20, valve element 12 rotates in conjunction with the gear, opening and closing the passage of cooling water from inlet 11a to outlet 11b (switching the communication state with the outside).

[0023] Furthermore, the gap between the shaft 13 and the cylindrical insertion portion 11d of the housing 11 is closed by a seal ring 21. This prevents the cooling water in the valve body 12 from leaking out from the cylindrical insertion portion 11d into the reducer accommodating space 17a.

[0024] In this embodiment, only one outlet 11b is provided in the circumferential direction of the housing 11 (see Figure 1), but this is not limited to this, and additional cooling water outlets may be formed at positions other than those shown in Figure 1 depending on the number and direction of the flow paths for discharging the cooling water.

[0025] In this embodiment, the valve device 1 is described as discharging the coolant flowing in from the inlet 11a toward the cooling path or the bypass path, but the connection configuration of the flow paths communicating with the valve device 1 is not limited to this and can be changed as appropriate depending on the specifications of the cooling circuit of the automobile. Also, the inlet 11a in Fig. 1 may be the coolant outlet, and the outlet 11b in Fig. 1 may be the coolant inlet.

[0026] In addition, in this embodiment, the seal member 15 is pressed against the outer cylinder 12b of the valve body 12 by the biasing force of a coil spring as shown in Fig. 1, but this is not limited to this. The seal member 15 may be realized by other structures as long as it can prevent leakage of cooling water that passes through the valve body 12 and is discharged to the adapter 14 side.

[0027] Next, the valve body 12, which is one of the elements constituting the valve device 1 of this embodiment, will be described in detail. Fig. 2(a) is a front view of the valve body shown in Fig. 1. Fig. 2(b) is a perspective view of the valve body shown in (a).

[0028] The valve element 12 includes an inner cylinder 12a, a spherical outer cylinder 12b disposed around the inner cylinder 12a, and a connecting end 12c connecting one axial end of the inner cylinder 12a and the outer cylinder 12b. A valve body space 12d is formed between the inner cylinder 12a and the outer cylinder 12b. In FIG. 2, the inner cylinder 12a and the outer cylinder 12b are connected by wall-shaped connecting ends 12c formed at the upper and lower ends. The outer cylinder 12b has a valve hole 12e that connects the valve body space 12d to the inlet 11a or the outlet 11b. As shown in FIG. 2(a), the valve hole 12e is large and extends over more than half the circumference of the outer cylinder 12b. The valve hole 12e is also provided with three reinforcement columns 12f. While the outer cylinder 12b of the valve element 12 is spherical in this embodiment, it may be cylindrical. In addition, in this embodiment, the connection end portions 12c are provided at the upper and lower ends of the valve body 12, but the connection end portion 12c may be provided at only one end. Furthermore, the connection end portion 12c does not necessarily have to be wall-shaped.

[0029] As shown in FIG. 1, the inner cylinder 12a of the valve body 12 is joined to the outer periphery of the shaft 13 when the shaft 13 passes through the inner cylinder 12a.

[0030] In the valve device 1 of this embodiment, the valve body space 12d and the inlet 11a are always in communication. When the valve body 12 rotates about the shaft 13 while the valve body space 12d and the inlet 11a are in communication and the valve hole 12e and the outlet 11b overlap, the inlet 11a, the valve body space 12d, and the outlet 11b are in communication, and cooling water flows from the inlet 11a side to the outlet 11b side. As a result, the cooling water taken into the valve body space 12d through the inlet 11a is released from the outlet 11b via the adapter 14, and the flow rate is controlled according to the opening degree of the valve hole 12e.

[0031] In the valve device 1 of this embodiment, as shown in Fig. 2(a), lattice-shaped ribs 12g (corresponding to the lattice-shaped processed portion in the claims) are provided on the inner periphery of the outer tube 12b of the valve body 12. In this embodiment, the ribs 12g, each 1 mm high and 1 mm wide, are provided in a lattice pattern on the inner periphery of the outer tube 12b. Here, the ribs 12g may have any shape that intersects in a lattice pattern, and are not limited to a vertical or horizontal intersecting shape, but may also have a diagonal intersecting shape.

[0032] Furthermore, on the inner circumference of the outer tube 12b of the valve body 12, the rib 12g may be provided on a part of the wall surface, but from the viewpoint of reinforcing the valve body 12, it is more preferable to provide it so that it reaches the peripheral portion of the valve hole 12e, and it is most preferable to provide it on the entire inner circumference of the outer tube 12b.

[0033] In this embodiment, the height of the ribs 12g is 1 mm, but is not limited to this. The height of the ribs 12g may be set so as not to abut against the inner tube 12a, as long as it is a height that effectively suppresses sink marks (one type of deformation defect) caused by the thickness of the resin. This height can be adjusted appropriately depending on the shape of the valve disc 12 and the resin used. That is, depending on the shape of the valve disc 12 and the type of resin used, the difference in thickness (shrinkage rate) between the outer tube 12b where the ribs 12g are provided and the thickness of the remaining portions of the outer tube 12b may be a factor in the occurrence of sink marks. Therefore, it is preferable to adjust the height, width, number, etc. of the ribs 12g appropriately to prevent the occurrence of sink marks. From the viewpoint of suppressing sink marks, the height of the ribs 12g is preferably 1 mm or less. From the viewpoint of strength, it is preferable to set the height of the ribs 12g to a level that allows the ribs 12g to be visible, such as 0.1 mm or more, 0.2 mm or more, or 0.3 mm or more.

[0034] In this embodiment, the inner periphery of the outer tube 12b of the valve disc 12 is provided with a grid-like rib 12g. However, the grid-like rib 12g may be replaced with a grid-like groove (corresponding to a grid-like processed portion in the claims). In this case, the groove provides clearance and disperses the effects of shrinkage and stress, which can cause warpage, thereby suppressing warpage and sink marks in the valve disc. The depth of the groove may be sufficient to effectively suppress sink marks and can be adjusted appropriately depending on the shape of the valve disc and the resin used. In other words, depending on the shape of the valve disc and the type of resin used, the difference in thickness between the grooved portion of the outer tube 12b and the remaining portions (difference in shrinkage rate) can cause sink marks, so it is preferable to adjust the depth, width, number, etc. of the grooves appropriately to prevent sink marks from occurring.

[0035] However, if lattice-shaped grooves are provided on the inner circumference of the outer tube 12b of the valve disc 12, the thickness of the grooved portions will be thinner and the thickness of the non-grooved portions will be thicker. Therefore, assuming that the outer tube 12b is thinned to a degree that does not pose a strength problem, the area of ​​the outer tube 12b that can be thinned to the limit is overwhelmingly smaller when lattice-shaped grooves are provided than when lattice-shaped ribs 12g are provided so that the outer tube 12b other than the rib 12g can be thinned to the limit. In other words, if lattice-shaped grooves are provided on the inner circumference of the outer tube 12b, warping and sink marks can be prevented, and a certain degree of effect can be obtained, but from the perspectives of the strength of the valve disc 12, weight reduction, and cost reduction, providing lattice-shaped ribs 12g is preferable to providing lattice-shaped grooves.

[0036] As described above, the valve device 1 of this embodiment includes a housing 11 having a coolant inlet 11a, an outlet 11b, and an internal space 11c communicating with these, a valve element 12 housed in the internal space 11c and rotating about a rotation axis to switch the communication state between the inlet 11a and the outlet 11b as a result of the rotation, a shaft 13 located on the rotation axis, a seal member 15 attached to the inlet 11a or the outlet 11b and in sliding contact with the outer periphery of the valve element 12, and a drive device that rotationally drives the valve element 12. The valve element 12 has an inner cylinder 12a, an outer cylinder 12b disposed on the outer periphery of the inner cylinder 12a, and a connecting end 12c connecting one axial end of the inner cylinder 12a and the outer cylinder 12b. In addition, a valve body space 12d is formed between the inner tube 12a and the outer tube 12b, and a valve hole 12e is formed in the outer tube 12b to connect the valve body space 12d to the inlet 11a or the outlet 11b, and a lattice-shaped processed portion (rib 12g or groove) is formed on the inner circumference of the outer tube 12b, the height of which does not reach the outer circumference of the inner tube 12a.

[0037] According to the valve device 1 of this embodiment, a lattice-shaped portion is formed on the inner periphery of the outer cylinder 12b, which prevents warping of the outer cylinder 12b. Furthermore, the height of the lattice-shaped portion is set so that it does not reach the outer periphery of the inner cylinder 12a, which prevents sink marks from forming on the outer periphery of the outer cylinder 12b. This prevents gaps from forming between the valve body 12 and the seal member 15 due to molding defects, thereby preventing coolant leakage.

[0038] Furthermore, by providing the lattice-shaped ribs 12g on the inner circumference of the outer tube 12b, the strength of the part can be increased, making it possible to further reduce the thickness of the outer tube 12b, particularly the thickness of the outer tube 12b other than the area of ​​the ribs 12g. Furthermore, if the thickness of the outer tube 12b is reduced to the limit, the flow of resin within the mold during resin molding may become poor. However, by providing the lattice-shaped ribs 12g, a resin flow path is formed within the mold, improving the flow of resin, making it easier for the resin to flow to the fine details. This improves the precision of the resin molding.

[0039] In the valve device 1 of this embodiment, the grid-shaped portion is made up of ribs 12g or grooves, and the height of the ribs 12g or the depth of the grooves may be 1 mm or less. This reliably prevents sink marks from forming on the outer periphery of the outer cylinder 12b and prevents leakage of the coolant.

[0040] In the valve device 1 of this embodiment, the lattice-shaped portion may extend to the periphery of the valve hole 12 e. This prevents deformation of the periphery of the valve hole 12 e, thereby efficiently preventing leakage of the coolant.

[0041] Although the valve device 1 of this embodiment has been described as being used in a cooling circuit for cooling an automobile engine, the invention is not limited to this and can also be applied to cooling the battery of an electric vehicle or the fuel cell stack of a fuel cell vehicle.

[0042] REFERENCE SIGNS LIST 1 valve device 11 housing 11a inlet 11b outlet 11c internal space 12 valve body 12a inner cylinder 12b outer cylinder 12c connection end 12d valve body internal space 12e valve hole 12g rib 13 shaft 15 sealing member

Claims

1. A valve device comprising: a housing in which a coolant inlet and outlet are formed, and an internal space communicating with these; a valve disc contained in the internal space and rotating about a rotation axis, switching the communication state between the inlet and outlet as the rotation occurs; a shaft located on the rotation axis; a seal member attached to the inlet or outlet and in sliding contact with the outer periphery of the valve disc; and a drive unit for rotating the valve disc, wherein the valve disc has an inner tube, an outer tube placed on the outer periphery of the inner tube, and a connecting end portion connecting one axial end of the inner tube and the outer tube, wherein an inner valve body space is formed between the inner tube and the outer tube, a valve hole is formed in the outer tube which allows the inner valve body space to communicate with the inlet or outlet, and a lattice-shaped processed portion is formed on the inner periphery of the outer tube so as not to reach the outer periphery of the inner tube.

2. The valve device according to claim 1, wherein the grid-like processed portion is made up of ribs or grooves, and the height of the ribs or the depth of the grooves is 1 mm or less.

3. The valve device according to claim 1 or 2, characterized in that the lattice-shaped processed portion reaches the periphery of the valve hole.

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