Thermostat device

Abstract

Provided is a thermostat device that facilitates attachment to a cover member or a housing that forms a flow passage for cooling water. A thermostat device 1 according to the present invention is incorporated in a cooling circuit of an automobile by sandwiching a flange 24 between a housing and a cover member that forms a flow passage for cooling water. The thermostat device includes an annular seal member 30 attached to an outer circumferential edge part including an outer circumferential edge 24b of the flange 24 and a circumferential portion of the outer circumferential edge. The seal member 30 has a fitting groove formed on the inner circumferential surface, and an outward projection 30b provided on the outer circumferential surface. Furthermore, in the present invention, a gap 34 is formed as a clearance for storing a part of the seal member 30, which is elastically deformed by pressing when the thermostat device 1 is incorporated in the cooling circuit.

Description

Technical Field

[0001] The present invention relates to a thermostat device.Background Art

[0002] A thermostat device includes a thermo-element containing a thermal expansion material that senses a temperature change of cooling water flowing in a flow passage between an engine and a radiator and expands and contracts, and functions to hold the cooling water within a predetermined temperature by opening and closing a control valve by forward and backward movements of a piston rod with the expansion and contraction of the thermal expansion material. The thermostat device, which functions as described above, is sandwiched between a cover member and a housing that form the flow passage for the cooling water to be integrally formed, and is incorporated into a cooling circuit of an automobile.

[0003] As an example of means for incorporating the above-described thermostat device into the cooling circuit, PTL 1 discloses a mounting structure for a thermostat that contributes to rationalizing the engine assembly process. In this structure, the thermostat is locked in a predetermined position within an inlet housing that forms part of a cooling medium flow passage through which cooling water from a radiator flows, and the thermostat will not fall off from the inlet housing during packaging or conveyance in the engine assembly process.

[0004] More specifically, as shown in FIG. 19, a conventional thermostat 200 includes a thermo-operating unit 221 that holds cooling water within a predetermined temperature range by opening and closing a valve (corresponding to the above-described control valve) by forward and backward movement of an actuating rod (corresponding to the above-described piston rod) with the expansion and contraction of a thermo-wax (corresponding to the above-described thermal expansion material) sealed within a valve case (corresponding to the above-described thermo-element), an annular support base 223 having an inner circumferential portion as a valve seat 222, a support frame 224 that is integrally formed with the support base 223 for guiding the valve box slidably along a longitudinal direction of the actuating rod with a spring that urges the valve toward the valve seat attached between the valve and itself, and a restriction frame 225 integrally formed with the support base 223 for restricting the projecting head portion of the actuating rod.

[0005] Furthermore, a plate-shaped flange portion 226 is continuously formed on the outer diameter side of the valve seat 222, and a gasket 227 is attached to the outer circumferential portion of the flange portion 226 so as to cover the outer circumferential portion thereof over both upper and lower surfaces (see FIG. 19).

[0006] Moreover, in the inner circumferential portion of the lower opening of the inlet housing 211, a step portion 212 that can receive the gasket 227 is provided over the entire circumference, and an outward projecting portion 228 that supports the thermostat 200 while maintaining an elastic force is formed as locking means in the edge portion of the outer circumference of the gasket 227. In the attachment structure described in PTL 1, with the thermostat 200 locked in the step portion 212 by the outward projecting portion 228, the gasket 227 is sandwiched between the inlet housing 211 and an engine body 213, thereby fixing the thermostat 200 within the cooling medium flow passage.

[0007] Specifically, when the gasket 227 is press-fitted into the step portion 212, the outward projecting portion 228 contacts the inner circumferential surface of the step portion 212 while maintaining the elastic force, and a bead portion 229 of the gasket 227 is in contact with the top surface of the step portion 212. Concurrently, the outward projecting portion 228 is elastically deformed by pressure, and the gasket 227 is held within the step portion 212 by the restoration elasticity thereof. Accordingly, the thermostat 200 does not drop, but is supported by the inner circumferential surface of the step portion 212 while maintaining the elastic force. This allows the thermostat 200 to be stably locked even before the inlet housing 211 and the engine body 213 are fastened and integrated.Citation ListPatent Literature

[0008] [PTL 1] JP-A-2008-50969Summary of InventionTechnical Problem

[0009] However, as is used in conventionally, when the gasket (corresponding to a seal member of an embodiment to be described later) 227 having the outward projecting portion 228 is attached to cover the outer circumferential portion of the flange portion 226, a large load is required for press-fitting the gasket 227 into the step portion 212 formed in the inlet housing (corresponding to a cover member of the embodiment to be described later) 211.

[0010] Specifically, in order to prevent the thermostat 200 from falling off from the inlet housing 211 during packaging and conveyance in the engine assembly process, it is required to further increase the restoring force generated by the elastic deformation of the outward projecting portion 228. However, in the mounting structure described in PTL 1, there is no means in the step portion 212 for releasing the pressure due to elastic deformation generated under the load during press fitting. The greater the restoring force due to the elastic deformation of the outward projecting portion 228, the more difficult it is to press-fit the gasket 227 into the step portion 212. In other words, there is a problem that, when the load required for press-fitting the gasket 227 increases from the viewpoint of preventing it from falling off, the mounting work of the thermostat 200 to the inlet housing 211 becomes more difficult.

[0011] The present invention was made in view of the above-described problem and aims to provide a thermostat device that facilitates mounting work on the cover member or housing, where the thermostat device is incorporated into a cooling circuit by clamping a flange with a sealing member attached thereto between a cover member and a housing, forming a cooling water flow path.Solution to Problem

[0012] A thermostat device according to the present invention includes a thermo-element incorporating a thermal expansion material that expands and contracts in response to the temperature of cooling water, a control valve attached to said thermo-element, and a flange forming a valve seat on which said control valve seats during expansion and contraction of said thermal expansion material, and a flange forming a valve seat on its inner circumferential portion where the control valve seats, wherein the thermostat device operates such that the control valve opens and closes due to movement of the thermo-element caused by advance and retraction of the piston rod, and is incorporated into the cooling circuit by sandwiching the flange between a cover member and a housing that form the cooling water flow passage, and is provided with a sealing member with an annular shape attached to the outer circumferential portion including the outer circumferential edge and the surrounding portions of the flange, sealing the connection between the cover member and the housing, and wherein the sealing member has a fitting groove portion formed on its inner surface to cover the outer circumferential portion of the flange, and outwardly projecting portions on its outer surface, and a specific gap as a clearance is formed to accommodate a portion of the sealing member that elastically deforms under the pressing force when the thermostat device is incorporated into the cooling circuit.

[0013] Specifically, in the thermostat device according to the invention, the gap is formed between the outer circumferential edge of the flange and the bottom surface of the fitting groove portion.

[0014] Alternatively, in the thermostat device according to the invention, a plurality of the outward projections are provided on the outer circumferential surface of the seal member, a cutout portion is provided in a part of the outer circumferential edge of the flange, a gap is formed between the outer circumferential edge of the cutout portion of the flange and the bottom surface of the fitting groove portion, and the cutout portion is provided to position correspond to the outward projection. In this case, in the thermostat device, the adjacent outward projections are disposed on the outer circumferential surface of the seal member so as to be offset toward the cover member side and the housing side, respectively when the cover member and the housing sandwich the flange. Furthermore, in the thermostat device, when a jiggle valve, or an auxiliary valve, is provided in the flange, the seal member has a positioning mark on the inner circumferential surface thereof, and the positioning mark is provided aligned with the cutout portion and the outward projection when the seal member is fitted based on the position of the jiggle valve.

[0015] Alternatively, in the thermostat device according to the invention, a plurality of outward projections are provided on the outer circumferential surface of the seal member. Furthermore, a plurality of ribs is provided on the bottom surface of the fitting groove portion which abut the outer circumferential edge of the outer circumferential portion of the flange when the outer circumferential portion of the flange is fitted in the seal member, and a gap is formed between the outer circumferential edge of the flange and the bottom surface of the fitting groove portion except where the ribs are located. The ribs may be disposed at positions deviated from the positions of the outward projections or disposed aligned with the outward projections.

[0016] Alternatively, in the thermostat device according to the invention, clearance grooves as gaps are intermittently provided in the seal member; each clearance groove is provided on one side surface of two opposing surfaces formed from an outer circumferential edge toward an inner circumferential portion of the seal member. Furthermore, in the thermostat device according to the invention, a plurality of outward projections are provided on the outer circumferential surface of the seal member, and the clearance grooves are provided near the outward projections. It is preferable that the clearance grooves are provided on the different surface sides.

[0017] Therefore, according to the present invention, a thermostat device can be provided that facilitates the mounting work onto a cover member or housing.Advantageous Effects of Invention

[0018] According to the invention, the mounting work of the thermostat device onto the cover member forming the flow passage of the cooling water or the housing can be facilitated, and thus the assembly work when the thermostat device is incorporated into the cooling circuit can be facilitated.Brief Description of Drawings

[0019] [FIG. 1] FIG. 1 is a view showing an example of a state in which a thermostat device according to the invention is incorporated therein in a cooling circuit of an automobile. [FIG. 2] FIG. 2 is a view showing an exploded configuration of a flow passage of cooling water including the thermostat device according to the invention. [FIG. 3] FIG. 3 is a view showing an example of a configuration of the thermostat device according to the invention. [FIG. 4] FIG. 4 is a view showing an example of an assembly method when the thermostat device according to the invention is incorporated into the cooling circuit. [FIG. 5] FIG. 5 is a view showing an example of the shape of a seal member. [FIG. 6] FIG. 6 is a schematic diagram showing a state in which the seal member is fitted in a flange. [FIG. 7] FIG. 7 is a view showing an example of the configuration of the thermostat device according to the invention. [FIG. 8] FIG. 8 is a schematic diagram showing a state in which the seal member is fitted in the flange. [FIG. 9] FIG. 9 is a view showing a modification of the thermostat device according to the invention. [FIG. 10] FIG. 10 is a view showing the appearance of the seal member. [FIG. 11] FIG. 11 is a schematic diagram of a positioning mark when the seal member is provided to overlap a jiggle valve. [FIG. 12] FIG. 12 is a view showing an example of the configuration of the thermostat device according to the invention. [FIG. 13] FIG. 13 is a view showing a cross-section of the seal member. [FIG. 14] FIG. 14 is a schematic diagram showing a state in which the seal member is fitted into the flange. [FIG. 15] FIG. 15 is a view showing a cross-section of the seal member. [FIG. 16] FIG. 16 is a schematic diagram showing a state in which the seal member is fitted into the flange. [FIG. 17] FIG. 17 is a view showing an example of the configuration of the thermostat device according to the invention. [FIG. 18] FIG. 18 is a view showing an example of the shape of the seal member. [FIG. 19] FIG. 19 is a view showing a configuration of a conventional thermostat. [Description of Embodiments]

[0020] Hereinafter, a thermostat device according to the invention will be described in detail with reference to the drawings. Note that this embodiment does not limit the scope of the invention. Furthermore, elements that can be described in the same manner in the specification and drawings of the application may have the same referential signs, and overlapping descriptions may be omitted.<First Embodiment>

[0021] First, a thermostat device of a first embodiment will be described in detail with reference to the drawings. For convenience of description, upward and downward directions in the drawings are referred to as "upper" and "lower".<Cooling Circuit>

[0022] FIG. 1 shows an example of a state in which the thermostat device according to the invention is incorporated therein into a cooling circuit of an automobile, FIG. 1(a) is a plan view, FIG. 1(b) shows a cross-section along line A-A', and FIG. 1(c) is an enlarged view showing a cross-section of a cover member along line A-A'. FIG. 2 is a view showing an exploded configuration of a flow passage of cooling water including the thermostat device. A thermostat device 1 of the present embodiment is disposed within the cooling circuit of the automobile for circulating the cooling water between an engine and a radiator. As shown in FIGS. 1 and 2, the thermostat device 1 is sandwiched between a cover member 2 forming the flow passage of the cooling water and a housing 3, and incorporated at a predetermined position of the cooling circuit.

[0023] In FIG. 1(b) and FIG. 2, a first inflow port 4 for introducing the cooling water from the radiator side is formed in the upper part in the drawings, and a second inflow port 5 and a third inflow port 6 for introducing the cooling water not via the radiator are formed in the lower part and on the right side in the drawings, respectively. Furthermore, an outflow port 7 for the cooling water is formed on the left side in the drawings.

[0024] Specifically, for example, when the temperature of the cooling water is higher than a predetermined temperature, a valve (a control valve 21 shown in FIG. 1(b)) for opening and closing a first cooling water flow passage as a passage for the cooling water flowing in from the first inflow port 4 is opened. Then, the cooling water flowing in via the first cooling water flow passage passes through the thermostat device 1 and flows from the outflow port 7 toward the engine side.

[0025] Furthermore, for example, when cooling water pressure abruptly rises within the water chamber of the engine, a valve (a relief valve 22 shown in FIG. 1(b)) for opening and closing a second cooling water flow passage as a passage for the cooling water flowing in from the second inflow port 5 is opened. Then, the cooling water flowing in via the second cooling water flow passage passes through the thermostat device 1 and flows from the outflow port 7 toward the engine side. The relief valve 22, which opens and closes the second cooling water flow passage, is used for pressure relief; it functions as a safety valve for preventing the cooling water pressure from being excessively high by opening to allow the cooling water to flow when the cooling water pressure is higher on the engine side.

[0026] In addition, in the present embodiment, a third cooling water flow passage in which the cooling water flowing out from the engine (cylinder head side) flows in from the third inflow port 6, not passing through the radiator (detoured), is formed. The cooling water flowing in via the third cooling water flow passage is constantly circulated as the cooling water for control to open and close the control valve 21 because of the temperature thereof, passes through the thermostat device 1, and flows from the outflow port 7 toward the engine side. Note that the cooling water may be cooling water flowing in from the third inflow port 6 via various devices such as an EGR cooler, a throttle body, a CVT warmer, or a heater.<Configuration of Thermostat Device>

[0027] FIG. 3 is a view showing an example of a configuration of the thermostat device of the first embodiment; (a) is a cross-sectional view of the thermostat device 1 before being attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B1-B1', and (c) is an enlarged view of the portion C.

[0028] The thermostat device 1 of the present embodiment is a thermostat device having a relief function, and includes a thermo-operating unit 11 that controls the flow of the cooling water flowing in through the first cooling water flow passage described above, and a relief operating unit 12 that controls the flow of the cooling water flowing in through the second cooling water flow passage, both described above. Furthermore, this thermostat device 1 is integrally formed such that the thermo-operating unit 11 is housed within an outer shell portion 25 comprising a frame 23 and a flange 24, and the relief operating unit 12 is fixed to one end of the longitudinal direction of the thermo-operating unit 11 (the lower end of the thermo-element 26 described later) (see FIG. 3(a)).

[0029] Furthermore, the thermo-operating unit 11 includes the thermo-element 26 having a cylindrical shape containing a thermal expansion material (wax) that expands and contracts in response to the temperature of the cooling water, and a piston rod 27 operates to advance and retract in the longitudinal direction of the thermo-operating unit 11 with the expansion and contraction of the thermal expansion material.

[0030] The control valve 21 (valve), having an umbrella shape, is attached to the thermo-element 26, and the control valve 21 is closed by abutting the valve seat 28 formed in the inner circumferential portion of the flange 24. A coil spring 29 is disposed to surround the thermo-element 26 with its one end in contact with a first spring seat portion 21a formed in a recess of the umbrella-shaped control valve 21, and the other end of the coil spring 29 is held by an annular second spring seat portion 23a formed on the lower end of the frame 23. Specifically, the second spring seat portion 23a formed on the frame 23 has an annularly formed hook-shaped recess, and the end of the coil spring 29 (corresponding to the other end of the coil spring 29 described above) is attached to the recess. Accordingly, the thermo-operating unit 11 is incorporated into the outer shell portion 25. Then, the control valve 21 is biased toward the valve-closing direction by the coil spring 29.

[0031] Furthermore, in the frame 23 of the thermos-operating unit 11, a tapered cylindrical portion 23b surrounded by the coil spring 29 is provided in the center part of the annular second spring seat portion 23a. At the end of the cylindrical portion 23b, an end of the thermo-element 26, substantially in the same shape as the end of the cylindrical portion 23b is inserted, and the cylindrical portion 23b guides the thermo-element 26 slidably along the axial direction (the longitudinal direction of the thermo-operating unit 11) in response to the advance and retraction motion of the piston rod 27.

[0032] In the outer shell portion 25, the flange 24 provided with a piston lock portion 24a having a bridge structure projecting at a predetermined gradient is connected to the upper end portion of the frame 23. The tip end of the piston rod 27 is fitted into the piston lock portion 24a provided in the flange 24. Accordingly, when the piston rod 27 advances, the reaction force thereof acts on the thermo-element 26, and the thermo-element 26 is pressed down, guided by the cylindrical portion 23b.

[0033] Furthermore, as shown in FIGS. 3(a) and 3(b), an annular seal member 30, which has a tapered shape that narrows toward the outer circumference, is mounted on the outer circumferential portion (the outer circumferential edge and the surrounding portion) and integrated on the flange 24 which constitutes the outer shell portion 25. When the thermostat device 1 is incorporated into the cooling circuit by the flange 24 thereof being clamped between the cover member 2 and the housing 3, the seal member 30 is to seal the connecting portion between the cover member 2 and the housing 3, which form part of the passage for the cooling water. The detailed shape and structure of the seal member 30 will be described later.

[0034] In the thermo-operating unit 11 configured as described above, when the piston rod 27 projects due to thermal expansion of the thermal expansion material, the thermo-element 26 and the control valve 21 move downward against the biasing force of the coil spring 29, and the control valve 21 is opened. Accordingly, the thermo-operating unit 11 causes the cooling water flowing in (the cooling water from the radiator side) through the first cooling water flow passage, to flow from the outflow port 7 toward the engine side. In other words, the thermo-operating unit 11 operates to alternate between the valve-closed state and the valve-open state by controlling the control valve 21 fixed to the thermo-element 26 and the valve seat 28 formed in the inner circumferential portion of the flange 24 contacting with or away from each other in response to the advance and retraction of the piston rod 27.

[0035] Meanwhile, the relief operating unit 12 includes a relief rod 31 as a valve shaft. One end side of the relief rod 31 is fixed to one end side in the longitudinal direction of the thermo-operating unit 11 (the lower end portion of the thermo-element 26), thereby integrating the relief operating unit 12 with the thermo-operating unit 11.

[0036] Furthermore, the relief valve 22, as a valve having a substantially plate shape, is fitted, assembled, and locked by an E-ring or the like on the other end side of the relief rod 31. The relief valve 22 is supported by being biased to a valve seat 33 (see FIG. 1(b)) which is formed at a predetermined position of the second cooling water flow passage in the housing 3 by a coil spring 32 disposed between the lower end portion of the thermo-element 26 and the relief valve 22 to surround the relief rod 31.

[0037] In the relief operating unit 12 configured as described above, the relief valve 22 has a structure to be seated on the valve seat 33 by the biasing force of the coil spring 32 and opened and closed according to the cooling water pressure on the second cooling water flow passage side. In other words, when the thermostat device 1 of the present embodiment is incorporated into the cover member 2 and the housing 3, the relief valve 22 is normally seated on the valve seat 33 (the relief valve 22 is a normally seated-type valve) by the biasing force of the coil spring 32 except when the cooling water pressure exceeds a predetermined value (upper limit value).<Assembly Method>

[0038] Subsequently, an assembly method when the thermostat device 1 of the present embodiment is incorporated in the cooling circuit will be described. It is assumed that, as shown in FIG. 1(c), a mounting groove portion 2a for mounting the flange 24, with the seal member 30 fitted therein, by press fit is provided in advance over the entire circumference on the inner circumference of the lower end opening in the cover member 2.

[0039] FIG. 4 shows an example of the assembly method when the thermostat device 1 is incorporated into the cooling circuit, and (a) to (c) sequentially show the first step to the third step in the assembly method (referred to as "first assembly method").

[0040] In the present embodiment, first, in the first step, the flange 24, with the seal member 30 fitted therein, is press-fitted in the mounting groove portion 2a (see FIG. 1(c)) provided in the cover member 2, and the thermostat device 1 and the cover member 2 are integrated.

[0041] Then, in the second step, the thermostat device 1, in a state of being fixed to the cover member 2 (the portion lower than the flange 24), is inserted into the housing 3 from the upper end opening thereof.

[0042] Finally, in the third step, the flange 24 with the seal member 30 fitted thereto is sandwiched between the lower end portion of the cover member 2 and the upper end portion of the housing 3 and held, and the cover member 2 and the housing 3 are fastened and integrated. When the cover member 2 and the housing 3 are fastened and integrally formed, the upper and lower larger-diameter portions formed of the tapered seal member 30 are also pressed and deformed into a compressed state. As a result, the connecting portion of the integrally formed members are sealed. Thus, the thermostat device 1 can be incorporated into the cooling circuit.<Details of Seal Member 30>

[0043] Subsequently, the shape and structure of the seal member 30 used for the thermostat device 1 of the present embodiment will be described in detail with reference to the drawings.

[0044] FIG. 5 shows an example of the shape of the seal member 30, (a) is a front view, (b) is a side view, and (c) is a perspective view. FIG. 6 is a schematic diagram showing a state in which the seal member 30 is fitted in the flange 24, and (a) is a schematic view of the state as viewed from the front, and (b) is a schematic view showing a cross-section along line D-D'.

[0045] The seal member 30 to be used for the thermostat device 1 of the present embodiment is, for example, an annular rubber ring has a tapered shape that narrows toward the outer circumference as shown in FIGS. 5 and 6, and on the inner circumferential surface thereof, a fitting groove portion 30a is formed over the entire circumference for fitting so as to cover both the upper and lower surfaces of the outer circumferential portion of the flange 24.

[0046] On the outer circumferential surface of the seal member 30, an outward projection 30b capable of supporting the thermostat device 1 by an elastic force is provided as locking means. It is preferable that a plurality of the outward projections 30b are provided at specific intervals for stably supporting the thermostat device 1. In the present embodiment, as an example, eight outward projections 30b are provided at equal intervals. With the outward projections 30b provided, when the flange 24 with the seal member 30 fitted thereto is press-fitted into the mounting groove portion 2a together with the outward projections 30b, the outward projections 30b come into contact (elastic contact) while keeping an elastic force with respect to an inner circumferential surface 2b of the mounting groove portion 2a (see FIG. 1(c)), and the annular one side surface of the seal member 30 comes into contact with an upper surface 2c of the mounting groove portion 2a (see FIG. 1(c)). The outward projections 30b are elastically deformed by pressure and the seal member 30 is locked to the inner circumferential surface 2b by the restoration elasticity (reaction force), and thus, the thermostat device 1 is supported by the elastic force kept with respect to the inner circumferential surface 2b of the mounting groove portion 2a without falling off when a hand is released. In other words, even before it is sandwiched between the cover member 2 and the housing 3 and fastened and integrated, the thermostat device 1 can be stably locked to the cover member 2.

[0047] Note that the intervals and the number of the outward projections 30b are not limited to those described above, but can be appropriately changed according to the specification of the thermostat device 1, the assembly method when the thermostat device 1 is incorporated into the cooling circuit, the work speed at assembly, or the like.

[0048] Furthermore, in the present embodiment, a specific gap is formed inside the fitting groove portion 30a for housing part of the seal member 30 that is elastically deformed by pressure when the thermostat device 1 is incorporated into the cooling circuit.

[0049] Specifically, as shown in FIGS. 3(c) and 6, a gap 34 is provided between an outer circumferential edge 24b of the flange 24 and a bottom surface 30c of the fitting groove portion 30a. The gap 34 is a space formed by satisfying a condition of "m, diameter of outer circumferential edge 24b < n, diameter of bottom surface 30c, and the width of the gap 34 may be equal over the entire circumference or not equal (the center of the outer circumferential edge 24b and the center of the bottom surface 30c do not necessarily coincide). In other words, as long as the seal member 30 is fitted to cover the upper and lower surfaces of the outer circumferential portion (the outer circumferential edge 24b and the surrounding portions) of the flange 24 over the entire circumference (see FIG. 6), it is not necessary that the width of the gap 34 is equal over the entire circumference and there may be a portion without the gap (a part in which the outer circumferential edge 24b and the bottom surface 30c are in contact).

[0050] By providing the gap 34 as the above-described specific gap, when the flange 24 with the seal member 30 fitted thereto is press-fitted into the mounting groove portion 2a, this gap 34 functions as a clearance (play) for the outward projections 30b and the surrounding portions that have been elastically deformed by pressing. Consequently, the load applied during press-fitting can be reduced, thereby facilitating the operation of mounting the thermostat device 1 to the cover member 2.

[0051] Since the load applied at the press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member 30 or damage due to compression cracking, can be significantly reduced.<Advantageous Effects>

[0052] As described above, the thermostat device 1 of the present embodiment includes the thermo-element 26 incorporating the thermal expansion material that expands and contracts in response to the temperature of the cooling water, the control valve 21 attached to the thermo-element 26, the piston rod 27 that advances and retracts with the expansion and contraction of the thermal expansion material, and the flange 24 forming the valve seat 28 for seating the control valve 21 in the inner circumferential portion, and the control valve 21 operates to open and close by the movements of the thermo-element 26 due to the advance and retraction of the piston rod 27. The thermostat device is incorporated into the cooling circuit of an automobile by sandwiching the flange 24 by the cover member 2, forming the flow passage of the cooling water and the housing 3, and includes the annular seal member 30 attached to the outer circumferential portion, including the outer circumferential edge 24b of the flange 24 and the surrounding portion.

[0053] The seal member 30 has the fitting groove portion 30a formed in the inner circumferential surface for fitting to cover the outer circumferential portion of the flange 24, and the outward projections 30b provided on the outer circumferential surface. Furthermore, in the present embodiment, the gap 34 is formed as a clearance for housing a part of the seal member 30 (the outward projections 30b and their vicinity) elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit. In the present embodiment, the gap 34 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 30c of the fitting groove portion 30a formed in the seal member 30.

[0054] Accordingly, the mounting work of the thermostat device 1 to the cover member 2 or the housing 3, which form the flow passage for the cooling water, can be facilitated, and thus the assembly work when the thermostat device 1 is incorporated into the cooling circuit of the automobile can be facilitated. In the thermostat device 1 of the present embodiment, the load applied during press fitting can be reduced. Thus, the mounting-work failures, such as defective sealing due to the seal member turning up or damage due to compression cracking, can be significantly reduced.

[0055] Note that, in the present embodiment, as an example, the case is described where the thermostat device having a relief function is incorporated into the cooling circuit of an automobile. However, the thermostat device to be incorporated into the cooling circuit is not limited to that. Another type of thermostat device can be similarly applied if it is the one in which the annular seal member is fitted to cover the upper and lower surfaces of the outer circumferential portion of the flange over the entire circumference, and the flange in which the seal member is fitted is sandwiched between the upper and lower surfaces and fixed.

[0056] In the present embodiment, the mounting groove portion 2a is provided in the inner circumference of the lower end opening in the cover member 2, but the invention is not limited to that. For example, the fitting groove portion may be provided, not at the cover member 2 side, but at the housing 3 side. Specifically, the fitting groove portion may be provided in the inner circumference of the upper end opening of the housing 3 over the entire circumference.

[0057] When the fitting groove portion is provided on the housing 3 side, first, in the first step, the flange 24 with the seal member 30 fitted therein is press-fitted into the fitting groove portion provided on the housing 3 side, and the thermostat device 1 and the housing 3 are integrated. Then, in the second step, the thermostat device 1 fixed to the housing 3 (the portion upper than the flange 24) is inserted into the cover member 2 from the lower end opening thereof. Finally, in the third step, the seal member 30 is sandwiched between the cover member 2 and the housing 3 and held, and then, the cover member 2 and the housing 3 are fastened and integrated (referred to as the second assembly method). Thus, the thermostat device 1 can be incorporated into the cooling circuit.

[0058] Since the thermostat device 1 used in the present embodiment has the relief valve 22 of the normally seated type as described above, if the flange 24 is press-fitted into the fitting groove portion provided at the housing 3 side, the thermostat device 1 may detach from the fitting groove portion by the biasing force of the coil spring 32. Accordingly, in the present embodiment, the first assembly method of press-fitting the flange 24 into the mounting groove portion 2a provided on the cover member 2 side is preferable to the second assembly method of press-fitting the flange 24 into the fitting groove portion provided on the housing 3 side. The second assembly method is suitable for a thermostat device without a relief function, for example.

[0059] In the present embodiment, the rubber ring with a rubber as a material is used as the seal member 30. However, the invention is not limited to that. Any material that fulfills the desired sealability and durability may be used.<Second Embodiment>

[0060] Subsequently, a thermostat device of a second embodiment will be described with reference to the drawings. The invention is not limited to this embodiment. Furthermore, the elements that can be described in the same manner as those of the above-described first embodiment may have the same signs, and the overlapping descriptions thereof may be omitted. The configurations of the cooling circuit shown in FIGS. 1 and 2 are the same as those of the above-described first embodiment.<Thermostat Device>

[0061] FIG. 7 shows an example of a configuration of the thermostat device of the second embodiment. (a) is a cross-sectional view of a thermostat device 101 before attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B2-B2', and (c) is an enlarged view of a portion E.

[0062] The thermostat device 101 of the present embodiment is a thermostat device having a relief function like that of the above-described first embodiment, but different from that of the first embodiment only in the shape of the flange (hereinafter, referred to as a flange 41). That is, the thermostat device 101 of the present embodiment is integrally formed, in which the thermo-operating unit 11 is housed within an outer shell portion 42 formed by the frame 23 and the flange 41 and the relief operating unit 12 is fixedly bonded to one end side in the longitudinal direction of the thermo-operating unit 11 (the lower end portion of the thermo-element 26) (see FIG. 7(a)).

[0063] Furthermore, as shown in FIGS. 7(a) and 7(b), in the flange 41, the annular seal member 30 is attached to the outer circumferential portion (the outer circumferential edge and the surrounding portions) and integrated. The seal member 30 has a tapered shape that narrows toward the outer circumference, for sealing the connecting portion between the cover member 2 and the housing 3, which form a part of the passage of the cooling water, when the thermostat device 101 is incorporated into the cooling circuit by sandwiching the flange 41 between the cover member 2 and the housing 3.

[0064] Furthermore, in the present embodiment, a specific gap is formed for housing part of the seal member 30 that is elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit.

[0065] Specifically, as shown in FIGS. 7(b) and (c), arc-shaped cutout portions 41a are provided in a part of the outer circumferential edge of the flange 41. The cutout portions 41a are preferably provided aligned with the outward projections 30b in order to facilitate the press fit of the flange 41 with the seal member 30 fitted therein into the mounting groove portion 2a of the cover member 2.

[0066] The cutout portions 41a are provided as the specific gaps described above, and thus, when the flange 41 with the seal member 30 fitted therein is press-fitted into the mounting groove portion 2a, because the gaps formed by the cutout portions 41a (the gaps between outer circumferential edge 41b of the cutout portions 41a of the flange 41 and the bottom surface 30c of the fitting groove portion 30a of the seal member 30) function as a "clearance (play)" of the outward projections 30b elastically deformed by pressure and the surrounding portion, the load applied during press fitting can be suppressed. Accordingly, the mounting work of the thermostat device 101 to the cover member 2 is facilitated.

[0067] In the present embodiment, the arc-shaped cutout portions 41a are provided as an example. However, the invention is not limited to that. For example, the shape of the cutout portion 41a may be other than an arc, as long as the cutout portion 41a forms the specified gap.

[0068] Other than the description of the formation of the specific gaps by the cutout portions 41a, the descriptions of "Configuration of Thermostat Device" and "Assembly Method" are similar to those of the first embodiment described above. I can be described by replacing the thermostat device 1 with the thermostat device 101, the flange 24 with the flange 41, and the outer shell portion 25 with the outer shell portion 42, respectively.<Details of Seal Member 30>

[0069] In the thermostat device 101 of the present embodiment, for the seal member, the seal member 30 is used similarly to that of the thermostat device 1 of the first embodiment described above. FIG. 8 is a schematic diagram showing a state in which the seal member 30 is fitted in the flange 41. In the present embodiment, as shown in FIG. 8, the seal member 30 is fitted to cover both the upper and lower surfaces of the outer circumferential portion (the outer circumferential edge 41b and the surrounding portions) of the flange 41 over the entire circumference.

[0070] In the above-described first embodiment, as shown in FIGS. 3(c) and 6, the gap 34 is provided between the outer circumferential edge 24b of the flange 24 and the bottom surface 30c of the fitting groove portion 30a, whereas, in the present embodiment, as described above, the cutout portions 41a are provided in the flange 41 aligned with the outward projections 30b of the seal member 30 to form the space (gap) to be a "clearance (play)" during press fitting. Thus, the gap 34 that serves as the same function is not an essential configuration.

[0071] Therefore, in FIG. 8, as an example, the case is shown where the gap 34 is provided between the outer circumferential edge 41b excluding the cutout portions 41a of the flange 41 and the bottom surface 30c of the fitting groove portion 30a. However, in the present embodiment, for example, as shown in FIG. 7(c), the outer circumferential edge 41b, excluding the cutout portions 41a of the flange 41, and the bottom surface 30c of the fitting groove portion 30a may be brought into contact to form a configuration without a gap 34.

[0072] Other than the description of the formation of the gaps, the description of "Details of Seal Member 30" is similar to that of the first embodiment described above. It can be described by replacing the thermostat device 1 with the thermostat device 101, the flange 24 with the flange 41, and the outer shell portion 25 with the outer shell portion 42, respectively.<Advantageous Effects>

[0073] As described above, in the thermostat device 101 of the present embodiment, the cutout portions 41a are provided in a part of the flange 41. In addition, gaps are formed between the outer circumferential edge 41b of the cutout portions 41a of the flange 41 and the bottom surface 30c of the fitting groove portion 30a; the gaps serve as clearances for housing part of the seal member 30 (the outward projections 30b and the surrounding portions) elastically deformed by pressure when the thermostat device 101 is incorporated into the cooling circuit. Furthermore, the cutout portions 41a are provided aligned with the outward projections 30b.

[0074] Accordingly, the mounting work of the thermostat device 101 to the cover member 2 or the housing 3, which form the flow passage for the cooling water, can be facilitated. Thus, the assembly work when the thermostat device 101 is incorporated into the cooling circuit of the automobile can be facilitated. In the thermostat device 101 of the present embodiment, the load applied during press fitting can be reduced. Thus, mounting work-related failures, such as defective sealing due to turning up of the seal member or damage due to compression cracking, can be significantly reduced.

[0075] <Modification of Second Embodiment>

[0076] Subsequently, a modification of the thermostat device of the second embodiment will be described in detail with reference to the drawings. As described above, in the thermostat device 101 of the second embodiment, the plurality of cutout portions 41a are intermittently provided on the outer circumferential edge 41b of the flange 41, and the seal member 30 is fitted into the flange 41 so that the positions of the cutout portions 41a and the outward projections 30b coincide, so that the press-fitting of the flange 41 with the seal member 30 fitted therein into the mounting groove portion 2a can be facilitated (see FIGS. 7(b), 7(c), and 8).

[0077] The modification further aims to facilitate the operation of fitting the cutout portion 41a aligned with the position of the outward projection 30b' (see FIG. 8).

[0078] FIG. 9 is a view showing the modification of the thermostat device of the second embodiment. (a) is a perspective view, and (b) is a plan view. FIG. 10 is a view showing the appearance of a seal member used in the modification, and (a) is a perspective view and (b) is a schematic view of the seal member as viewed from a side surface side.

[0079] A thermostat device 101' in the present modification has the same structure as thermostat device 101, except for the shape of the seal member. In the present modification, for example, positioning is performed using the jiggle valve 41c, or an auxiliary air vent valve (see FIG. 9), when the seal member 30' is fitted into the flange 41. Thus, the fitting of the seal member 30' into the flange 41 is made easier.

[0080] In the above-described thermostat device 101 of the second embodiment, for convenience of description, the jiggle valve 41c is not particularly mentioned. However, similarly, a jiggle valve (not shown) functions as an auxiliary valve for the air vent. In the present modification, as an example, a case where twelve of the outward projections 30b' of the seal member 30' are provided at equal intervals (in the thermostat device 101 of the second embodiment, eight outward projections 30b are provided as an example) is described. Therefore, in the thermostat device 101' with the seal member 30' fitted therein shown in FIG. 9(a), twelve cutout portions 41a are provided at equal intervals, and, similar to the second embodiment, it is assumed that the positions of the cutout portion 41a and the outward protrusion 30b' coincide (see FIG. 8 for the state in which the seal member 30' is fitted in the flange 41).

[0081] The seal member 30' used in the present modification is an annular rubber ring (see FIG. 10(a)) similar to that in the second embodiment. The fitting groove portion 30a for fitting to cover the upper and lower surfaces of the outer circumferential portion (the outer circumferential edge 41b and the surrounding portions) of the flange 41 is formed over the entire circumference on the inner circumferential surface.

[0082] On the outer circumferential surface of the seal member 30', the outward projections 30b' that can support the thermostat device 101' by an elastic force are provided as locking means. In the present modification, as described above, twelve outward projections 30b' are provided at equal intervals. Furthermore, as shown in FIG. 10(b), the adjacent outward projections 30b' are alternately disposed on the upside of the outer circumferential surface and the downside of the outer circumferential surface of the seal member 30' as viewed from the side surface side. In other words, the outward projections 30b' are disposed on the outer circumferential surface of the seal member 30' to be distributed at the cover member 2 side (corresponding to the upside of the outer circumferential surface) and the housing 3 side (corresponding to the downside of the outer circumferential surface) when the cover member 2 and the housing 3 sandwich the flange 41. Here, for convenience, the outward projections 30b' provided on the cover member 2 side are referred to as the upper outward projections 30d, and the outward projections 30b' provided on the housing 3 side are referred to as the lower outward projections 30e.

[0083] By providing these outward projections 30b' (upper outward projection 30d, lower outward projection 30e), when the flange 41 with the sealing member 30' inserted is press-fitted into the mounting groove portion 2a of the cover member 2 together with the outward projections 30b', the upper outward projection 30d contacts the inner circumferential surface 2b of the mounting groove portion 2a (see FIG. 1(c)) while maintaining elasticity (elastic contact), and the annular side surface of the sealing member 30' abuts against the upper surface 2c of the mounting groove portion 2a (see FIG. 1(c)). Here, the upper outward projections 30d are elastically deformed under pressure and the seal member 30' is locked to the inner circumferential surface 2b by the restoration elasticity (reaction force), The thermostat device 101' is supported by the elastic force against the inner circumferential surface 2b of the mounting groove portion 2a. preventing it from falling off when the hand is released. In other words, the thermostat device 101' can be stably locked to the cover member 2, even before it is sandwiched between the cover member 2 and the housing 3, and fastened and integrated.

[0084] In the present modification, as an example, the upper outward projections 30d and the lower outward projections 30e are alternately provided. However, for example, when the mounting groove portion 2a is provided in the inner circumference of the lower end opening in the cover member 2, the outward projections 30b' that function for fall prevention in the thermostat device 101' shown in FIG. 9(a) are the upper outward projections 30d (the outward projections 30b' at the cover member 2 side), and the gaps that function to suppress the load applied during the press fitting are those formed by the cutout portions 41a that correspond to the upper outward projections 30d. In this case, though the lower outward projections 30e do not function for fall prevention or suppression of the load applied during press fitting, the upper outward projections 30d and the lower outward projections 30e are alternately provided, so the same effects are achieved without paying attention to the surfaces (front and back surfaces) of the annular seal member 30'. In other words, it does not matter which surface of the annular seal member 30' is attached to the cover member 2 side.

[0085] Conversely, when the fitting groove portion is provided on the housing 3 side, the outward projections 30b' that function to prevent falls in the thermostat device 101' shown in FIG. 9(a) are the lower outward projections 30e (the outward projections 30b' at the housing 3 side), as opposed to the above description. The gaps that function to suppress the load applied during press fitting are gaps formed by the cutout portions 41a that correspond to the lower outward projections 30e.

[0086] As shown in FIGS. 9 and 10(a), a positioning mark 30f is provided on the inner circumferential surface of the seal member 30' used in the present modification. The positioning mark 30f includes two projections, for example. When the seal member 30' is fitted such that the jiggle valve 41c provided in the flange 41 is located between the two projections, the positions of the cutout portions 41a and the outward projections 30b' align automatically. Thus, aligning the positions of the cutout portions 41a and the outward projections 30b' can be simplified, thereby making the fitting work of the seal member 30' into the flange 41 easier.

[0087] In other words, by the positioning using the above-described positioning mark 30f, the positions of the cutout portions 41a of the flange 41 and the outward projections 30b' and the seal member 30' can be easily matched. Furthermore, by providing the upper outward projections 30d and the lower outward projections 30e, when the seal member 30' is fitted in the flange 41, fitting can be performed without paying attention to the surfaces (front and back surfaces) of the annular seal member 30'.

[0088] The above-described positioning mark 30f is not limited thereto, but can be any shape and structure. In the present modification, as an example, the positioning mark 30f is formed by the two projections. However, as long as the positioning mark 30f can implement positioning that matches the positions of the cutout portions 41a and the outward projections 30b', for example, a sign or a figure as a mark may be stamped on the seal member 30'.

[0089] As shown in FIG. 11 (the outward projections 30b' are omitted in the drawing), when the seal member 30' is provided to overlap the jiggle valve 41c, a cutout may be provided in the seal member 30' so as to avoid the jiggle valve 41c. Accordingly, the cutout portion can be used as a positioning mark (positioning mark 30f).<Third Embodiment>

[0090] Subsequently, a thermostat device of a third embodiment will be described with reference to the drawings. This embodiment does not limit the scope of the invention. Furthermore, the elements that can be described in the same manner as those of the above-described first embodiment may have the same signs, and the overlapping descriptions thereof may be omitted. The configurations of the cooling circuit shown in FIGS. 1 and 2 are the same as those of the above-described first embodiment.<Thermostat Device>

[0091] FIG. 12 shows an example of a configuration of the thermostat device of the third embodiment, (a) is a cross-sectional view of a thermostat device 102 before attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B3-B3', and (c) is an enlarged view of a portion F. The thermostat device 102 of the present embodiment differs from the thermostat device 1 of the first embodiment only in the structure of the seal member (hereinafter, referred to as a seal member 51).

[0092] Therefore, the descriptions of "Configuration of Thermostat Device" and "Assembly Method" other than the above description are similar to those in the first embodiment described above, and it can be described by replacing the thermostat device 1 with the thermostat device 102 and the seal member 30 with the seal member 51, respectively.<Details of Seal Member 51>

[0093] Subsequently, the shape and structure of the seal member 51 to be used for the thermostat device 102 of the present embodiment will be described in detail with reference to the drawings.

[0094] FIG. 13 shows a cross-section of the seal member 51 along line B3-B3' to be used in the thermostat device 102 of the present embodiment (see FIG. 12(a)). FIG. 14 is a schematic diagram showing a state in which the seal member 51 is fitted into the flange 24. The appearance (a front view, a side view, and a perspective view) of the seal member 51 is the same as the seal member 30 used in the thermostat device 1 of the above-described first embodiment (see FIG. 5).

[0095] As shown in FIG. 5, the seal member 51 to be used in the thermostat device 102 of the present embodiment is an annular rubber ring with a tapered shape that narrows toward the outer circumference, and a fitting groove portion 51a for fitting to cover the upper and lower surfaces of the outer circumferential portion of the flange 24 is formed over the entire circumference on the inner circumferential surface. The seal member 30 used in the first embodiment and the seal member 51 to be used in the present embodiment are different only in the internal structure of the fitting groove portion.

[0096] Specifically, as shown in FIGS. 13 and 14, a plurality of ribs 51c having a convex shape projecting toward the flange 24 is provided on a bottom surface 51b of the fitting groove portion 51a to be in contact with the outer circumferential edge 24b when the flange 24 is fitted in the seal member 51. Accordingly, a gap 52 is formed as the above-described specific gap between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a excluding the ribs 51c. It is preferable that the ribs 51c are disposed at positions that deviate from the positions of the respective outward projections 30b. The ribs 51c are provided at those positions, and thus, when the flange 24 with the seal member 51 fitted therein is press-fitted in the mounting groove portion 2a, the gap 52 functions as a "clearance (play)" of the outward projections 30b and surrounding portions thereof elastically deformed by pressure, and the load applied during press fitting can be suppressed. Accordingly, the mounting work of the thermostat device 102 to the cover member 2 is facilitated, achieving the same effect as the first embodiment.

[0097] Since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member 51, damage due to compression cracking, can be significantly reduced.

[0098] Other than the recitation of the internal structure of the fitting groove portion 51a and the formation of the gap 52, the description of <Details of Seal Member 51> is similar to <The Details of seal Member 30> in the first embodiment described above. It can be described by replacing thermostat device 1 with thermostat device 102 and seal member 30 with seal member 51, respectively<Advantageous Effects>

[0099] As described above, in the thermostat device 102 of the present embodiment, the gap 52, which is a clearance for housing a part of the seal member 51 (the outward projections 30b and the surrounding portions) elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit, is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a other than the ribs 51c. It is preferable that the ribs 51c are positioned in locations that deviate from the positions of the respective outward projections 30b.

[0100] Accordingly, the mounting work of the thermostat device 102 to the cover member 2 forming the flow passage of the cooling water or the housing 3 can be made easier, and thus the assembly work when the thermostat device 102 is incorporated into the cooling circuit of the automobile can be made easier. In the thermostat device 102 of the present embodiment, since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member, damage due to compression cracking, can be significantly reduced.<Third Embodiment: First Modification>

[0101] In the above-described third embodiment, the ribs 51c are positioned in locations that deviate from the positions of the respective outward projections 30b, however, the invention is not limited to that. For example, as a first modification of the above-described seal member 51, the ribs 51c may be disposed aligned with the respective outward projections 30b provided in the seal member 51. FIG. 15 shows a cross-section along line B-B' of the seal member 51 in the first modification. FIG. 16 is a schematic diagram showing a state in which the seal member 51 of the first modification is fitted in the flange 24. Also, in the first modification, the gap 52 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a, other than the ribs 51c.

[0102] The first modification is effective, for example, when the hardness of the used seal member (for example, the hardness is about 60) is lower than the hardness of a seal member generally used (for example, the hardness is about 70), and the more deformable seal member is used. By providing the ribs 51c at the positions in FIGS. 15 and 16, when the flange 24 with the seal member 51 fitted therein is press-fitted in the mounting groove portion 2a, the gap 52 formed at the position deviated from the positions of the respective outward projections 30b functions as a "clearance (play)" of the outward projections 30b elastically deformed by pressure, the ribs 51c, and the surrounding portions, and thus the load applied during press fitting can be suppressed.<Third Embodiment: Second Modification>

[0103] In the third embodiment described above, a plurality of ribs 51c were provided based on the position of each outward protrusion 30b. However, it is also possible to provide the plurality of ribs 51c without using the position of the outward protrusions 30b as a reference. Specifically, instead of the outward projections 30b above described, an annular outward projection (not shown) as locking means may be provided over the entire circumference on the outer circumferential surface of the seal member 51. In addition, a plurality of ribs 51c having a convex shape may be provided in any position on the bottom surface 51b of the fitting groove portion 51a. Also, in the modification, the gap 52 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a, excluding the ribs 51c.<Fourth Embodiment>

[0104] Subsequently, a thermostat device of a fourth embodiment will be described with reference to the drawings. This embodiment does not limit the scope of the invention. Furthermore, the elements that can be described in the same manner as those of the above-described first embodiment may have the same signs, and the overlapping descriptions thereof may be omitted. The configurations of the cooling circuit shown in FIGS. 1 and 2 are the same as those of the above-described first embodiment.<Thermostat Device>

[0105] FIG. 17 shows an example of a configuration of the thermostat device of the fourth embodiment, (a) is a cross-sectional view of a thermostat device 103 before attached to the cover member 2 and the housing 3, and (b) is an enlarged view of the portion G. The thermostat device 103 of the present embodiment differs from the thermostat device 1 of the first embodiment in the appearance shape of the seal member (hereinafter, referred to as a seal member 61) and the depth of the fitting groove portion (hereinafter, referred to as a fitting groove portion 61a).

[0106] Therefore, other than the above description, the descriptions of <Configuration of Thermostat Device> and <Assembly Method> are similar to those in the first embodiment described above, and they can be described by replacing the thermostat device 1 with the thermostat device 103 and the seal member 30 with the seal member 61, respectively.<Details of Seal Member 61>

[0107] Subsequently, the shape and structure of the seal member 61 used for the thermostat device 103 of the present embodiment will be described in detail with reference to the drawings.

[0108] FIG. 18 is a view showing an example of the shape of the seal member 61; (a) is a perspective view, and (b) is an enlarged view of the portion H.

[0109] For example, as shown in FIGS. 17 and 18, the seal member 61 to be used in the thermostat device 103 of the present embodiment is an annular rubber ring with a tapered shape that narrows toward the outer circumference, and the fitting groove portion 61a for fitting to cover the upper and lower surfaces of the outer circumferential portion of the flange 24 is formed over the entire surface on the inner circumferential surface. In the present embodiment, as an example, the seal member 61 is the annular rubber ring with a tapered shape that narrows toward the outer circumference. However, the invention is not limited to that. For example, any shape that can seal the cooling water such as an annular rubber ring formed by parallel opposing surfaces (upper surface and lower surface) may be adopted.

[0110] In the present embodiment, the gap 34 formed in the above-described first embodiment is not provided. As shown in FIG. 17(b), the outer circumferential edge 24b of the flange 24 and the bottom surface 61b of the fitting groove portion 61a are in contact along the entire circumference. In other words, the depth of the fitting groove portion differs from that of the seal member 30 in the first embodiment.

[0111] The seal member 61 to be used for the thermostat device 103 of the present embodiment has a specific gap to house part of the seal member that is elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit.

[0112] Specifically, as shown in FIG. 18, clearance grooves 61c as the specific gaps described above are intermittently provided, and the clearance grooves 61c are respectively provided on the surface of the upside (hereinafter, referred to as an upper surface) or the surface of the downside (hereinafter, referred to as a lower surface) of the seal member 61. In other words, each clearance groove 61c is provided on one of the two opposing surfaces (upper surface, lower surface) formed from the outer circumferential edge toward the inner circumferential portion of the sealing member 61. In the present embodiment, as an example, eight outward projections 30b are provided on the outer circumferential surface of the seal member 61 (see FIG. 18(a)), and eight clearance grooves 61c are individually provided around these outward projections 30b. Furthermore, in the present embodiment, when the seal member 61 is fitted in the flange 24, at least one clearance groove 61c is located on the underside of the outward projection 30b (see FIG. 17).

[0113] By providing the clearance grooves 61c are provided as described above, when the flange 24 with the seal member 61 fitted therein is press-fitted into the mounting groove portion 2a, the gaps by the clearance grooves 61c function as "clearances (plays)" of the outward projections 30b elastically deformed by pressure and the surrounding portions, and the load applied during press fitting can be suppressed. Accordingly, similar to the effect of the first embodiment, the mounting work of the thermostat device 103 to the cover member 2 is facilitated.

[0114] Since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member 61, damage due to compression cracking, can be significantly reduced.

[0115] For example, when the clearance grooves are formed over the entire circumference of the outer circumferential surface of the seal member, the volume of the seal member becomes smaller (the volume of the gaps as the clearances of the elastically deformed outward projections 30b is larger), and consequently, the sealing power may decrease when the seal member is sandwiched between the cover member 2 and the housing 3. In contrast, as described in the present embodiment, when the clearance grooves 61c are intermittently formed, the reduction in volume of the seal member 61 due to the formation of the clearance grooves 61c is suppressed, and consequently, the sealing power can be sufficiently secured when the seal member 61 is sandwiched between the cover member 2 and the housing 3.

[0116] Note that the seal member 61 may be provided with all of the clearance grooves 61c on the same surface side (the upper surface side or the lower surface side). However, in this case, when the seal member 61 is fitted into the flange 24, the seal members 61 are fitted while individually checking orientation so that the clearance grooves 61c are on the lower side of the outward projections 30b (see FIG. 17). Accordingly, from the viewpoint of ease of operation when fitting the seal member 61 to be used in the thermostat device 103 of this embodiment into the flange 24, it is preferable that the adjacent clearance grooves 61c do not locate on the same surface side (upper or lower) as much as possible. Accordingly, the clearance grooves 61c are distributedly disposed on both surfaces of the seal member 61. Approximately half of the clearance grooves 61c are located on the underside of the outward projections 30b without regard to the orientation of the seal member 61, and thus allowing the seal member 61 to be easily fitted into the flange.

[0117] In the present embodiment, as an example, the outward projections 30b are intermittently provided as in the other embodiment. However, the outward projections 30b are not necessarily intermittent. For example, the outward projections 30b may be formed annularly over the entire circumference of the outer circumferential surface of the seal member 61. When the outward projections 30b may be formed on the entire outer circumference surface of the seal member 61, the clearance grooves 61c function as clearances (plays) during press fitting when the clearance grooves 61c are intermittently formed (for example, when the eight clearance grooves 61c are intermittently formed as described above).

[0118] Other than the description of the appearance of the seal member 61 (clearance grooves 61c), the depth of the fitting groove portion 61a, and the formation of the gaps described above, the description of <Details of Seal Member 61> is similar to that of <Details of Seal Member 30> in the first embodiment described above, and it can be described by replacement of the thermostat device 1 with the thermostat device 103 and the seal member 30 with the seal member 61, respectively.<Advantageous Effects>

[0119] As described above, in the thermostat device 103 of the present embodiment, the seal member 61 is provided with clearance grooves as gaps intermittently, and each of the clearance grooves is provided on one side surface of two opposing surfaces formed from the outer circumferential edge toward the inner circumferential portion of the seal member 61. When a plurality of outward projections 30b are provided on the outer circumferential surface of the seal member 61, the seal member 61 is provided with the clearance grooves 61c around the outward projections 30b on one side surface of the two opposing surfaces formed from the outer circumferential edge to the inner circumferential portion.

[0120] Accordingly, the mounting work of the thermostat device 103 to the cover member 2 forming the flow passage of the cooling water or to the housing 3 can be facilitated, and thus the assembly work can be facilitated when the thermostat device 103 is incorporated into the cooling circuit of the automobile. In the thermostat device 103 of the present embodiment, since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member, damage due to compression cracking, can be significantly reduced.

[0121] Furthermore, in the present embodiment, since the clearance grooves 61c are intermittently formed, the volume reduction of the seal member 61 due to the formation of the clearance grooves 61c can be suppressed. As a result, the sealing power when the seal member is sandwiched between the cover member 2 and the housing 3 can be sufficiently secured.

[0122] Although not explicitly mentioned in the description of the respective embodiments, the respective embodiments and modifications except the first modification of the third embodiment are effective when, for example, the hardness of the used seal member is not lower than the hardness of a seal member generally used (for example, with a hardness of about 70) or relatively harder, the seal member which is harder to deform is used.

[0123] The shapes and structures of the thermostat devices of the first to fourth embodiments are not limited to the shapes and structures of the thermostat devices of the above-described respective embodiments, and alterations, changes can be appropriately made to the shapes and structures of the respective portions according to the specifications, the usage environments of the devices.Reference Signs List

[0124] 1, 101, 101', 102, 103 thermostat device 2 cover member 2a fitting groove portion 2b inner circumferential surface 2c upper surface 3 housing 4 first inflow port 5 second inflow port 6 third inflow port 7 outflow port 11 thermo-operating unit 12 relief operating unit 21 control valve 21a first spring seat portion 22 relief valve 23 frame 23a second spring seat portion 23b cylindrical portion 24, 41 flange 24a piston lock portion 24b outer circumferential edge 25, 42 outer shell portion 26 thermo-element 27 piston rod 28, 33 valve seat 29 coil spring 30, 30', 51, 61 seal member 30a, 51a, 61a fitting groove portion 30b, 30b' outward projection 30c, 51b, 61b bottom surface 30d upper outward projection 30e lower outward projection 30f positioning mark 31 relief rod 32 coil spring 34, 52 gap 41a cutout portion 41b outer circumferential edge 41c jiggle valve 51c rib 61c clearance groove

Examples

first embodiment

[0021]First, a thermostat device of a first embodiment will be described in detail with reference to the drawings. For convenience of description, upward and downward directions in the drawings are referred to as "upper" and "lower".

[0022]FIG. 1 shows an example of a state in which the thermostat device according to the invention is incorporated therein into a cooling circuit of an automobile, FIG. 1(a) is a plan view, FIG. 1(b) shows a cross-section along line A-A', and FIG. 1(c) is an enlarged view showing a cross-section of a cover member along line A-A'. FIG. 2 is a view showing an exploded configuration of a flow passage of cooling water including the thermostat device. A thermostat device 1 of the present embodiment is disposed within the cooling circuit of the automobile for circulating the cooling water between an engine and a radiator. As shown in FIGS. 1 and 2, the thermostat device 1 is sandwiched between a cover member 2 forming the flow passage of the cooling water and ...

second embodiment

[0061]FIG. 7 shows an example of a configuration of the thermostat device of the (a) is a cross-sectional view of a thermostat device 101 before attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B2-B2', and (c) is an enlarged view of a portion E.

[0062]The thermostat device 101 of the present embodiment is a thermostat device having a relief function like that of the above-described first embodiment, but different from that of the first embodiment only in the shape of the flange (hereinafter, referred to as a flange 41). That is, the thermostat device 101 of the present embodiment is integrally formed, in which the thermo-operating unit 11 is housed within an outer shell portion 42 formed by the frame 23 and the flange 41 and the relief operating unit 12 is fixedly bonded to one end side in the longitudinal direction of the thermo-operating unit 11 (the lower end portion of the thermo-element 26) (see FIG. 7(a)).

[0063]Furthermore, as shown in...

third embodiment

[0101]In the above-described third embodiment, the ribs 51c are positioned in locations that deviate from the positions of the respective outward projections 30b, however, the invention is not limited to that. For example, as a first modification of the above-described seal member 51, the ribs 51c may be disposed aligned with the respective outward projections 30b provided in the seal member 51. FIG. 15 shows a cross-section along line B-B' of the seal member 51 in the first modification. FIG. 16 is a schematic diagram showing a state in which the seal member 51 of the first modification is fitted in the flange 24. Also, in the first modification, the gap 52 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a, other than the ribs 51c.

[0102]The first modification is effective, for example, when the hardness of the used seal member (for example, the hardness is about 60) is lower than the hardness of a seal...

Technical Field

[0001] The present invention relates to a thermostat device.Background Art

[0002] A thermostat device includes a thermo-element containing a thermal expansion material that senses a temperature change of cooling water flowing in a flow passage between an engine and a radiator and expands and contracts, and functions to hold the cooling water within a predetermined temperature by opening and closing a control valve by forward and backward movements of a piston rod with the expansion and contraction of the thermal expansion material. The thermostat device, which functions as described above, is sandwiched between a cover member and a housing that form the flow passage for the cooling water to be integrally formed, and is incorporated into a cooling circuit of an automobile.

[0003] As an example of means for incorporating the above-described thermostat device into the cooling circuit, PTL 1 discloses a mounting structure for a thermostat that contributes to rationalizing the engine assembly process. In this structure, the thermostat is locked in a predetermined position within an inlet housing that forms part of a cooling medium flow passage through which cooling water from a radiator flows, and the thermostat will not fall off from the inlet housing during packaging or conveyance in the engine assembly process.

[0004] More specifically, as shown in FIG. 19, a conventional thermostat 200 includes a thermo-operating unit 221 that holds cooling water within a predetermined temperature range by opening and closing a valve (corresponding to the above-described control valve) by forward and backward movement of an actuating rod (corresponding to the above-described piston rod) with the expansion and contraction of a thermo-wax (corresponding to the above-described thermal expansion material) sealed within a valve case (corresponding to the above-described thermo-element), an annular support base 223 having an inner circumferential portion as a valve seat 222, a support frame 224 that is integrally formed with the support base 223 for guiding the valve box slidably along a longitudinal direction of the actuating rod with a spring that urges the valve toward the valve seat attached between the valve and itself, and a restriction frame 225 integrally formed with the support base 223 for restricting the projecting head portion of the actuating rod.

[0005] Furthermore, a plate-shaped flange portion 226 is continuously formed on the outer diameter side of the valve seat 222, and a gasket 227 is attached to the outer circumferential portion of the flange portion 226 so as to cover the outer circumferential portion thereof over both upper and lower surfaces (see FIG. 19).

[0006] Moreover, in the inner circumferential portion of the lower opening of the inlet housing 211, a step portion 212 that can receive the gasket 227 is provided over the entire circumference, and an outward projecting portion 228 that supports the thermostat 200 while maintaining an elastic force is formed as locking means in the edge portion of the outer circumference of the gasket 227. In the attachment structure described in PTL 1, with the thermostat 200 locked in the step portion 212 by the outward projecting portion 228, the gasket 227 is sandwiched between the inlet housing 211 and an engine body 213, thereby fixing the thermostat 200 within the cooling medium flow passage.

[0007] Specifically, when the gasket 227 is press-fitted into the step portion 212, the outward projecting portion 228 contacts the inner circumferential surface of the step portion 212 while maintaining the elastic force, and a bead portion 229 of the gasket 227 is in contact with the top surface of the step portion 212. Concurrently, the outward projecting portion 228 is elastically deformed by pressure, and the gasket 227 is held within the step portion 212 by the restoration elasticity thereof. Accordingly, the thermostat 200 does not drop, but is supported by the inner circumferential surface of the step portion 212 while maintaining the elastic force. This allows the thermostat 200 to be stably locked even before the inlet housing 211 and the engine body 213 are fastened and integrated.Citation ListPatent Literature

[0008] [PTL 1] JP-A-2008-50969Summary of InventionTechnical Problem

[0009] However, as is used in conventionally, when the gasket (corresponding to a seal member of an embodiment to be described later) 227 having the outward projecting portion 228 is attached to cover the outer circumferential portion of the flange portion 226, a large load is required for press-fitting the gasket 227 into the step portion 212 formed in the inlet housing (corresponding to a cover member of the embodiment to be described later) 211.

[0010] Specifically, in order to prevent the thermostat 200 from falling off from the inlet housing 211 during packaging and conveyance in the engine assembly process, it is required to further increase the restoring force generated by the elastic deformation of the outward projecting portion 228. However, in the mounting structure described in PTL 1, there is no means in the step portion 212 for releasing the pressure due to elastic deformation generated under the load during press fitting. The greater the restoring force due to the elastic deformation of the outward projecting portion 228, the more difficult it is to press-fit the gasket 227 into the step portion 212. In other words, there is a problem that, when the load required for press-fitting the gasket 227 increases from the viewpoint of preventing it from falling off, the mounting work of the thermostat 200 to the inlet housing 211 becomes more difficult.

[0011] The present invention was made in view of the above-described problem and aims to provide a thermostat device that facilitates mounting work on the cover member or housing, where the thermostat device is incorporated into a cooling circuit by clamping a flange with a sealing member attached thereto between a cover member and a housing, forming a cooling water flow path.Solution to Problem

[0012] A thermostat device according to the present invention includes a thermo-element incorporating a thermal expansion material that expands and contracts in response to the temperature of cooling water, a control valve attached to said thermo-element, and a flange forming a valve seat on which said control valve seats during expansion and contraction of said thermal expansion material, and a flange forming a valve seat on its inner circumferential portion where the control valve seats, wherein the thermostat device operates such that the control valve opens and closes due to movement of the thermo-element caused by advance and retraction of the piston rod, and is incorporated into the cooling circuit by sandwiching the flange between a cover member and a housing that form the cooling water flow passage, and is provided with a sealing member with an annular shape attached to the outer circumferential portion including the outer circumferential edge and the surrounding portions of the flange, sealing the connection between the cover member and the housing, and wherein the sealing member has a fitting groove portion formed on its inner surface to cover the outer circumferential portion of the flange, and outwardly projecting portions on its outer surface, and a specific gap as a clearance is formed to accommodate a portion of the sealing member that elastically deforms under the pressing force when the thermostat device is incorporated into the cooling circuit.

[0013] Specifically, in the thermostat device according to the invention, the gap is formed between the outer circumferential edge of the flange and the bottom surface of the fitting groove portion.

[0014] Alternatively, in the thermostat device according to the invention, a plurality of the outward projections are provided on the outer circumferential surface of the seal member, a cutout portion is provided in a part of the outer circumferential edge of the flange, a gap is formed between the outer circumferential edge of the cutout portion of the flange and the bottom surface of the fitting groove portion, and the cutout portion is provided to position correspond to the outward projection. In this case, in the thermostat device, the adjacent outward projections are disposed on the outer circumferential surface of the seal member so as to be offset toward the cover member side and the housing side, respectively when the cover member and the housing sandwich the flange. Furthermore, in the thermostat device, when a jiggle valve, or an auxiliary valve, is provided in the flange, the seal member has a positioning mark on the inner circumferential surface thereof, and the positioning mark is provided aligned with the cutout portion and the outward projection when the seal member is fitted based on the position of the jiggle valve.

[0015] Alternatively, in the thermostat device according to the invention, a plurality of outward projections are provided on the outer circumferential surface of the seal member. Furthermore, a plurality of ribs is provided on the bottom surface of the fitting groove portion which abut the outer circumferential edge of the outer circumferential portion of the flange when the outer circumferential portion of the flange is fitted in the seal member, and a gap is formed between the outer circumferential edge of the flange and the bottom surface of the fitting groove portion except where the ribs are located. The ribs may be disposed at positions deviated from the positions of the outward projections or disposed aligned with the outward projections.

[0016] Alternatively, in the thermostat device according to the invention, clearance grooves as gaps are intermittently provided in the seal member; each clearance groove is provided on one side surface of two opposing surfaces formed from an outer circumferential edge toward an inner circumferential portion of the seal member. Furthermore, in the thermostat device according to the invention, a plurality of outward projections are provided on the outer circumferential surface of the seal member, and the clearance grooves are provided near the outward projections. It is preferable that the clearance grooves are provided on the different surface sides.

[0017] Therefore, according to the present invention, a thermostat device can be provided that facilitates the mounting work onto a cover member or housing.Advantageous Effects of Invention

[0018] According to the invention, the mounting work of the thermostat device onto the cover member forming the flow passage of the cooling water or the housing can be facilitated, and thus the assembly work when the thermostat device is incorporated into the cooling circuit can be facilitated.Brief Description of Drawings

[0019] [FIG. 1] FIG. 1 is a view showing an example of a state in which a thermostat device according to the invention is incorporated therein in a cooling circuit of an automobile. [FIG. 2] FIG. 2 is a view showing an exploded configuration of a flow passage of cooling water including the thermostat device according to the invention. [FIG. 3] FIG. 3 is a view showing an example of a configuration of the thermostat device according to the invention. [FIG. 4] FIG. 4 is a view showing an example of an assembly method when the thermostat device according to the invention is incorporated into the cooling circuit. [FIG. 5] FIG. 5 is a view showing an example of the shape of a seal member. [FIG. 6] FIG. 6 is a schematic diagram showing a state in which the seal member is fitted in a flange. [FIG. 7] FIG. 7 is a view showing an example of the configuration of the thermostat device according to the invention. [FIG. 8] FIG. 8 is a schematic diagram showing a state in which the seal member is fitted in the flange. [FIG. 9] FIG. 9 is a view showing a modification of the thermostat device according to the invention. [FIG. 10] FIG. 10 is a view showing the appearance of the seal member. [FIG. 11] FIG. 11 is a schematic diagram of a positioning mark when the seal member is provided to overlap a jiggle valve. [FIG. 12] FIG. 12 is a view showing an example of the configuration of the thermostat device according to the invention. [FIG. 13] FIG. 13 is a view showing a cross-section of the seal member. [FIG. 14] FIG. 14 is a schematic diagram showing a state in which the seal member is fitted into the flange. [FIG. 15] FIG. 15 is a view showing a cross-section of the seal member. [FIG. 16] FIG. 16 is a schematic diagram showing a state in which the seal member is fitted into the flange. [FIG. 17] FIG. 17 is a view showing an example of the configuration of the thermostat device according to the invention. [FIG. 18] FIG. 18 is a view showing an example of the shape of the seal member. [FIG. 19] FIG. 19 is a view showing a configuration of a conventional thermostat. [Description of Embodiments]

[0020] Hereinafter, a thermostat device according to the invention will be described in detail with reference to the drawings. Note that this embodiment does not limit the scope of the invention. Furthermore, elements that can be described in the same manner in the specification and drawings of the application may have the same referential signs, and overlapping descriptions may be omitted.<First Embodiment>

[0021] First, a thermostat device of a first embodiment will be described in detail with reference to the drawings. For convenience of description, upward and downward directions in the drawings are referred to as "upper" and "lower".<Cooling Circuit>

[0022] FIG. 1 shows an example of a state in which the thermostat device according to the invention is incorporated therein into a cooling circuit of an automobile, FIG. 1(a) is a plan view, FIG. 1(b) shows a cross-section along line A-A', and FIG. 1(c) is an enlarged view showing a cross-section of a cover member along line A-A'. FIG. 2 is a view showing an exploded configuration of a flow passage of cooling water including the thermostat device. A thermostat device 1 of the present embodiment is disposed within the cooling circuit of the automobile for circulating the cooling water between an engine and a radiator. As shown in FIGS. 1 and 2, the thermostat device 1 is sandwiched between a cover member 2 forming the flow passage of the cooling water and a housing 3, and incorporated at a predetermined position of the cooling circuit.

[0023] In FIG. 1(b) and FIG. 2, a first inflow port 4 for introducing the cooling water from the radiator side is formed in the upper part in the drawings, and a second inflow port 5 and a third inflow port 6 for introducing the cooling water not via the radiator are formed in the lower part and on the right side in the drawings, respectively. Furthermore, an outflow port 7 for the cooling water is formed on the left side in the drawings.

[0024] Specifically, for example, when the temperature of the cooling water is higher than a predetermined temperature, a valve (a control valve 21 shown in FIG. 1(b)) for opening and closing a first cooling water flow passage as a passage for the cooling water flowing in from the first inflow port 4 is opened. Then, the cooling water flowing in via the first cooling water flow passage passes through the thermostat device 1 and flows from the outflow port 7 toward the engine side.

[0025] Furthermore, for example, when cooling water pressure abruptly rises within the water chamber of the engine, a valve (a relief valve 22 shown in FIG. 1(b)) for opening and closing a second cooling water flow passage as a passage for the cooling water flowing in from the second inflow port 5 is opened. Then, the cooling water flowing in via the second cooling water flow passage passes through the thermostat device 1 and flows from the outflow port 7 toward the engine side. The relief valve 22, which opens and closes the second cooling water flow passage, is used for pressure relief; it functions as a safety valve for preventing the cooling water pressure from being excessively high by opening to allow the cooling water to flow when the cooling water pressure is higher on the engine side.

[0026] In addition, in the present embodiment, a third cooling water flow passage in which the cooling water flowing out from the engine (cylinder head side) flows in from the third inflow port 6, not passing through the radiator (detoured), is formed. The cooling water flowing in via the third cooling water flow passage is constantly circulated as the cooling water for control to open and close the control valve 21 because of the temperature thereof, passes through the thermostat device 1, and flows from the outflow port 7 toward the engine side. Note that the cooling water may be cooling water flowing in from the third inflow port 6 via various devices such as an EGR cooler, a throttle body, a CVT warmer, or a heater.<Configuration of Thermostat Device>

[0027] FIG. 3 is a view showing an example of a configuration of the thermostat device of the first embodiment; (a) is a cross-sectional view of the thermostat device 1 before being attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B1-B1', and (c) is an enlarged view of the portion C.

[0028] The thermostat device 1 of the present embodiment is a thermostat device having a relief function, and includes a thermo-operating unit 11 that controls the flow of the cooling water flowing in through the first cooling water flow passage described above, and a relief operating unit 12 that controls the flow of the cooling water flowing in through the second cooling water flow passage, both described above. Furthermore, this thermostat device 1 is integrally formed such that the thermo-operating unit 11 is housed within an outer shell portion 25 comprising a frame 23 and a flange 24, and the relief operating unit 12 is fixed to one end of the longitudinal direction of the thermo-operating unit 11 (the lower end of the thermo-element 26 described later) (see FIG. 3(a)).

[0029] Furthermore, the thermo-operating unit 11 includes the thermo-element 26 having a cylindrical shape containing a thermal expansion material (wax) that expands and contracts in response to the temperature of the cooling water, and a piston rod 27 operates to advance and retract in the longitudinal direction of the thermo-operating unit 11 with the expansion and contraction of the thermal expansion material.

[0030] The control valve 21 (valve), having an umbrella shape, is attached to the thermo-element 26, and the control valve 21 is closed by abutting the valve seat 28 formed in the inner circumferential portion of the flange 24. A coil spring 29 is disposed to surround the thermo-element 26 with its one end in contact with a first spring seat portion 21a formed in a recess of the umbrella-shaped control valve 21, and the other end of the coil spring 29 is held by an annular second spring seat portion 23a formed on the lower end of the frame 23. Specifically, the second spring seat portion 23a formed on the frame 23 has an annularly formed hook-shaped recess, and the end of the coil spring 29 (corresponding to the other end of the coil spring 29 described above) is attached to the recess. Accordingly, the thermo-operating unit 11 is incorporated into the outer shell portion 25. Then, the control valve 21 is biased toward the valve-closing direction by the coil spring 29.

[0031] Furthermore, in the frame 23 of the thermos-operating unit 11, a tapered cylindrical portion 23b surrounded by the coil spring 29 is provided in the center part of the annular second spring seat portion 23a. At the end of the cylindrical portion 23b, an end of the thermo-element 26, substantially in the same shape as the end of the cylindrical portion 23b is inserted, and the cylindrical portion 23b guides the thermo-element 26 slidably along the axial direction (the longitudinal direction of the thermo-operating unit 11) in response to the advance and retraction motion of the piston rod 27.

[0032] In the outer shell portion 25, the flange 24 provided with a piston lock portion 24a having a bridge structure projecting at a predetermined gradient is connected to the upper end portion of the frame 23. The tip end of the piston rod 27 is fitted into the piston lock portion 24a provided in the flange 24. Accordingly, when the piston rod 27 advances, the reaction force thereof acts on the thermo-element 26, and the thermo-element 26 is pressed down, guided by the cylindrical portion 23b.

[0033] Furthermore, as shown in FIGS. 3(a) and 3(b), an annular seal member 30, which has a tapered shape that narrows toward the outer circumference, is mounted on the outer circumferential portion (the outer circumferential edge and the surrounding portion) and integrated on the flange 24 which constitutes the outer shell portion 25. When the thermostat device 1 is incorporated into the cooling circuit by the flange 24 thereof being clamped between the cover member 2 and the housing 3, the seal member 30 is to seal the connecting portion between the cover member 2 and the housing 3, which form part of the passage for the cooling water. The detailed shape and structure of the seal member 30 will be described later.

[0034] In the thermo-operating unit 11 configured as described above, when the piston rod 27 projects due to thermal expansion of the thermal expansion material, the thermo-element 26 and the control valve 21 move downward against the biasing force of the coil spring 29, and the control valve 21 is opened. Accordingly, the thermo-operating unit 11 causes the cooling water flowing in (the cooling water from the radiator side) through the first cooling water flow passage, to flow from the outflow port 7 toward the engine side. In other words, the thermo-operating unit 11 operates to alternate between the valve-closed state and the valve-open state by controlling the control valve 21 fixed to the thermo-element 26 and the valve seat 28 formed in the inner circumferential portion of the flange 24 contacting with or away from each other in response to the advance and retraction of the piston rod 27.

[0035] Meanwhile, the relief operating unit 12 includes a relief rod 31 as a valve shaft. One end side of the relief rod 31 is fixed to one end side in the longitudinal direction of the thermo-operating unit 11 (the lower end portion of the thermo-element 26), thereby integrating the relief operating unit 12 with the thermo-operating unit 11.

[0036] Furthermore, the relief valve 22, as a valve having a substantially plate shape, is fitted, assembled, and locked by an E-ring or the like on the other end side of the relief rod 31. The relief valve 22 is supported by being biased to a valve seat 33 (see FIG. 1(b)) which is formed at a predetermined position of the second cooling water flow passage in the housing 3 by a coil spring 32 disposed between the lower end portion of the thermo-element 26 and the relief valve 22 to surround the relief rod 31.

[0037] In the relief operating unit 12 configured as described above, the relief valve 22 has a structure to be seated on the valve seat 33 by the biasing force of the coil spring 32 and opened and closed according to the cooling water pressure on the second cooling water flow passage side. In other words, when the thermostat device 1 of the present embodiment is incorporated into the cover member 2 and the housing 3, the relief valve 22 is normally seated on the valve seat 33 (the relief valve 22 is a normally seated-type valve) by the biasing force of the coil spring 32 except when the cooling water pressure exceeds a predetermined value (upper limit value).<Assembly Method>

[0038] Subsequently, an assembly method when the thermostat device 1 of the present embodiment is incorporated in the cooling circuit will be described. It is assumed that, as shown in FIG. 1(c), a mounting groove portion 2a for mounting the flange 24, with the seal member 30 fitted therein, by press fit is provided in advance over the entire circumference on the inner circumference of the lower end opening in the cover member 2.

[0039] FIG. 4 shows an example of the assembly method when the thermostat device 1 is incorporated into the cooling circuit, and (a) to (c) sequentially show the first step to the third step in the assembly method (referred to as "first assembly method").

[0040] In the present embodiment, first, in the first step, the flange 24, with the seal member 30 fitted therein, is press-fitted in the mounting groove portion 2a (see FIG. 1(c)) provided in the cover member 2, and the thermostat device 1 and the cover member 2 are integrated.

[0041] Then, in the second step, the thermostat device 1, in a state of being fixed to the cover member 2 (the portion lower than the flange 24), is inserted into the housing 3 from the upper end opening thereof.

[0042] Finally, in the third step, the flange 24 with the seal member 30 fitted thereto is sandwiched between the lower end portion of the cover member 2 and the upper end portion of the housing 3 and held, and the cover member 2 and the housing 3 are fastened and integrated. When the cover member 2 and the housing 3 are fastened and integrally formed, the upper and lower larger-diameter portions formed of the tapered seal member 30 are also pressed and deformed into a compressed state. As a result, the connecting portion of the integrally formed members are sealed. Thus, the thermostat device 1 can be incorporated into the cooling circuit.<Details of Seal Member 30>

[0043] Subsequently, the shape and structure of the seal member 30 used for the thermostat device 1 of the present embodiment will be described in detail with reference to the drawings.

[0044] FIG. 5 shows an example of the shape of the seal member 30, (a) is a front view, (b) is a side view, and (c) is a perspective view. FIG. 6 is a schematic diagram showing a state in which the seal member 30 is fitted in the flange 24, and (a) is a schematic view of the state as viewed from the front, and (b) is a schematic view showing a cross-section along line D-D'.

[0045] The seal member 30 to be used for the thermostat device 1 of the present embodiment is, for example, an annular rubber ring has a tapered shape that narrows toward the outer circumference as shown in FIGS. 5 and 6, and on the inner circumferential surface thereof, a fitting groove portion 30a is formed over the entire circumference for fitting so as to cover both the upper and lower surfaces of the outer circumferential portion of the flange 24.

[0046] On the outer circumferential surface of the seal member 30, an outward projection 30b capable of supporting the thermostat device 1 by an elastic force is provided as locking means. It is preferable that a plurality of the outward projections 30b are provided at specific intervals for stably supporting the thermostat device 1. In the present embodiment, as an example, eight outward projections 30b are provided at equal intervals. With the outward projections 30b provided, when the flange 24 with the seal member 30 fitted thereto is press-fitted into the mounting groove portion 2a together with the outward projections 30b, the outward projections 30b come into contact (elastic contact) while keeping an elastic force with respect to an inner circumferential surface 2b of the mounting groove portion 2a (see FIG. 1(c)), and the annular one side surface of the seal member 30 comes into contact with an upper surface 2c of the mounting groove portion 2a (see FIG. 1(c)). The outward projections 30b are elastically deformed by pressure and the seal member 30 is locked to the inner circumferential surface 2b by the restoration elasticity (reaction force), and thus, the thermostat device 1 is supported by the elastic force kept with respect to the inner circumferential surface 2b of the mounting groove portion 2a without falling off when a hand is released. In other words, even before it is sandwiched between the cover member 2 and the housing 3 and fastened and integrated, the thermostat device 1 can be stably locked to the cover member 2.

[0047] Note that the intervals and the number of the outward projections 30b are not limited to those described above, but can be appropriately changed according to the specification of the thermostat device 1, the assembly method when the thermostat device 1 is incorporated into the cooling circuit, the work speed at assembly, or the like.

[0048] Furthermore, in the present embodiment, a specific gap is formed inside the fitting groove portion 30a for housing part of the seal member 30 that is elastically deformed by pressure when the thermostat device 1 is incorporated into the cooling circuit.

[0049] Specifically, as shown in FIGS. 3(c) and 6, a gap 34 is provided between an outer circumferential edge 24b of the flange 24 and a bottom surface 30c of the fitting groove portion 30a. The gap 34 is a space formed by satisfying a condition of "m, diameter of outer circumferential edge 24b < n, diameter of bottom surface 30c, and the width of the gap 34 may be equal over the entire circumference or not equal (the center of the outer circumferential edge 24b and the center of the bottom surface 30c do not necessarily coincide). In other words, as long as the seal member 30 is fitted to cover the upper and lower surfaces of the outer circumferential portion (the outer circumferential edge 24b and the surrounding portions) of the flange 24 over the entire circumference (see FIG. 6), it is not necessary that the width of the gap 34 is equal over the entire circumference and there may be a portion without the gap (a part in which the outer circumferential edge 24b and the bottom surface 30c are in contact).

[0050] By providing the gap 34 as the above-described specific gap, when the flange 24 with the seal member 30 fitted thereto is press-fitted into the mounting groove portion 2a, this gap 34 functions as a clearance (play) for the outward projections 30b and the surrounding portions that have been elastically deformed by pressing. Consequently, the load applied during press-fitting can be reduced, thereby facilitating the operation of mounting the thermostat device 1 to the cover member 2.

[0051] Since the load applied at the press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member 30 or damage due to compression cracking, can be significantly reduced.<Advantageous Effects>

[0052] As described above, the thermostat device 1 of the present embodiment includes the thermo-element 26 incorporating the thermal expansion material that expands and contracts in response to the temperature of the cooling water, the control valve 21 attached to the thermo-element 26, the piston rod 27 that advances and retracts with the expansion and contraction of the thermal expansion material, and the flange 24 forming the valve seat 28 for seating the control valve 21 in the inner circumferential portion, and the control valve 21 operates to open and close by the movements of the thermo-element 26 due to the advance and retraction of the piston rod 27. The thermostat device is incorporated into the cooling circuit of an automobile by sandwiching the flange 24 by the cover member 2, forming the flow passage of the cooling water and the housing 3, and includes the annular seal member 30 attached to the outer circumferential portion, including the outer circumferential edge 24b of the flange 24 and the surrounding portion.

[0053] The seal member 30 has the fitting groove portion 30a formed in the inner circumferential surface for fitting to cover the outer circumferential portion of the flange 24, and the outward projections 30b provided on the outer circumferential surface. Furthermore, in the present embodiment, the gap 34 is formed as a clearance for housing a part of the seal member 30 (the outward projections 30b and their vicinity) elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit. In the present embodiment, the gap 34 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 30c of the fitting groove portion 30a formed in the seal member 30.

[0054] Accordingly, the mounting work of the thermostat device 1 to the cover member 2 or the housing 3, which form the flow passage for the cooling water, can be facilitated, and thus the assembly work when the thermostat device 1 is incorporated into the cooling circuit of the automobile can be facilitated. In the thermostat device 1 of the present embodiment, the load applied during press fitting can be reduced. Thus, the mounting-work failures, such as defective sealing due to the seal member turning up or damage due to compression cracking, can be significantly reduced.

[0055] Note that, in the present embodiment, as an example, the case is described where the thermostat device having a relief function is incorporated into the cooling circuit of an automobile. However, the thermostat device to be incorporated into the cooling circuit is not limited to that. Another type of thermostat device can be similarly applied if it is the one in which the annular seal member is fitted to cover the upper and lower surfaces of the outer circumferential portion of the flange over the entire circumference, and the flange in which the seal member is fitted is sandwiched between the upper and lower surfaces and fixed.

[0056] In the present embodiment, the mounting groove portion 2a is provided in the inner circumference of the lower end opening in the cover member 2, but the invention is not limited to that. For example, the fitting groove portion may be provided, not at the cover member 2 side, but at the housing 3 side. Specifically, the fitting groove portion may be provided in the inner circumference of the upper end opening of the housing 3 over the entire circumference.

[0057] When the fitting groove portion is provided on the housing 3 side, first, in the first step, the flange 24 with the seal member 30 fitted therein is press-fitted into the fitting groove portion provided on the housing 3 side, and the thermostat device 1 and the housing 3 are integrated. Then, in the second step, the thermostat device 1 fixed to the housing 3 (the portion upper than the flange 24) is inserted into the cover member 2 from the lower end opening thereof. Finally, in the third step, the seal member 30 is sandwiched between the cover member 2 and the housing 3 and held, and then, the cover member 2 and the housing 3 are fastened and integrated (referred to as the second assembly method). Thus, the thermostat device 1 can be incorporated into the cooling circuit.

[0058] Since the thermostat device 1 used in the present embodiment has the relief valve 22 of the normally seated type as described above, if the flange 24 is press-fitted into the fitting groove portion provided at the housing 3 side, the thermostat device 1 may detach from the fitting groove portion by the biasing force of the coil spring 32. Accordingly, in the present embodiment, the first assembly method of press-fitting the flange 24 into the mounting groove portion 2a provided on the cover member 2 side is preferable to the second assembly method of press-fitting the flange 24 into the fitting groove portion provided on the housing 3 side. The second assembly method is suitable for a thermostat device without a relief function, for example.

[0059] In the present embodiment, the rubber ring with a rubber as a material is used as the seal member 30. However, the invention is not limited to that. Any material that fulfills the desired sealability and durability may be used.<Second Embodiment>

[0060] Subsequently, a thermostat device of a second embodiment will be described with reference to the drawings. The invention is not limited to this embodiment. Furthermore, the elements that can be described in the same manner as those of the above-described first embodiment may have the same signs, and the overlapping descriptions thereof may be omitted. The configurations of the cooling circuit shown in FIGS. 1 and 2 are the same as those of the above-described first embodiment.<Thermostat Device>

[0061] FIG. 7 shows an example of a configuration of the thermostat device of the second embodiment. (a) is a cross-sectional view of a thermostat device 101 before attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B2-B2', and (c) is an enlarged view of a portion E.

[0062] The thermostat device 101 of the present embodiment is a thermostat device having a relief function like that of the above-described first embodiment, but different from that of the first embodiment only in the shape of the flange (hereinafter, referred to as a flange 41). That is, the thermostat device 101 of the present embodiment is integrally formed, in which the thermo-operating unit 11 is housed within an outer shell portion 42 formed by the frame 23 and the flange 41 and the relief operating unit 12 is fixedly bonded to one end side in the longitudinal direction of the thermo-operating unit 11 (the lower end portion of the thermo-element 26) (see FIG. 7(a)).

[0063] Furthermore, as shown in FIGS. 7(a) and 7(b), in the flange 41, the annular seal member 30 is attached to the outer circumferential portion (the outer circumferential edge and the surrounding portions) and integrated. The seal member 30 has a tapered shape that narrows toward the outer circumference, for sealing the connecting portion between the cover member 2 and the housing 3, which form a part of the passage of the cooling water, when the thermostat device 101 is incorporated into the cooling circuit by sandwiching the flange 41 between the cover member 2 and the housing 3.

[0064] Furthermore, in the present embodiment, a specific gap is formed for housing part of the seal member 30 that is elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit.

[0065] Specifically, as shown in FIGS. 7(b) and (c), arc-shaped cutout portions 41a are provided in a part of the outer circumferential edge of the flange 41. The cutout portions 41a are preferably provided aligned with the outward projections 30b in order to facilitate the press fit of the flange 41 with the seal member 30 fitted therein into the mounting groove portion 2a of the cover member 2.

[0066] The cutout portions 41a are provided as the specific gaps described above, and thus, when the flange 41 with the seal member 30 fitted therein is press-fitted into the mounting groove portion 2a, because the gaps formed by the cutout portions 41a (the gaps between outer circumferential edge 41b of the cutout portions 41a of the flange 41 and the bottom surface 30c of the fitting groove portion 30a of the seal member 30) function as a "clearance (play)" of the outward projections 30b elastically deformed by pressure and the surrounding portion, the load applied during press fitting can be suppressed. Accordingly, the mounting work of the thermostat device 101 to the cover member 2 is facilitated.

[0067] In the present embodiment, the arc-shaped cutout portions 41a are provided as an example. However, the invention is not limited to that. For example, the shape of the cutout portion 41a may be other than an arc, as long as the cutout portion 41a forms the specified gap.

[0068] Other than the description of the formation of the specific gaps by the cutout portions 41a, the descriptions of "Configuration of Thermostat Device" and "Assembly Method" are similar to those of the first embodiment described above. I can be described by replacing the thermostat device 1 with the thermostat device 101, the flange 24 with the flange 41, and the outer shell portion 25 with the outer shell portion 42, respectively.<Details of Seal Member 30>

[0069] In the thermostat device 101 of the present embodiment, for the seal member, the seal member 30 is used similarly to that of the thermostat device 1 of the first embodiment described above. FIG. 8 is a schematic diagram showing a state in which the seal member 30 is fitted in the flange 41. In the present embodiment, as shown in FIG. 8, the seal member 30 is fitted to cover both the upper and lower surfaces of the outer circumferential portion (the outer circumferential edge 41b and the surrounding portions) of the flange 41 over the entire circumference.

[0070] In the above-described first embodiment, as shown in FIGS. 3(c) and 6, the gap 34 is provided between the outer circumferential edge 24b of the flange 24 and the bottom surface 30c of the fitting groove portion 30a, whereas, in the present embodiment, as described above, the cutout portions 41a are provided in the flange 41 aligned with the outward projections 30b of the seal member 30 to form the space (gap) to be a "clearance (play)" during press fitting. Thus, the gap 34 that serves as the same function is not an essential configuration.

[0071] Therefore, in FIG. 8, as an example, the case is shown where the gap 34 is provided between the outer circumferential edge 41b excluding the cutout portions 41a of the flange 41 and the bottom surface 30c of the fitting groove portion 30a. However, in the present embodiment, for example, as shown in FIG. 7(c), the outer circumferential edge 41b, excluding the cutout portions 41a of the flange 41, and the bottom surface 30c of the fitting groove portion 30a may be brought into contact to form a configuration without a gap 34.

[0072] Other than the description of the formation of the gaps, the description of "Details of Seal Member 30" is similar to that of the first embodiment described above. It can be described by replacing the thermostat device 1 with the thermostat device 101, the flange 24 with the flange 41, and the outer shell portion 25 with the outer shell portion 42, respectively.<Advantageous Effects>

[0073] As described above, in the thermostat device 101 of the present embodiment, the cutout portions 41a are provided in a part of the flange 41. In addition, gaps are formed between the outer circumferential edge 41b of the cutout portions 41a of the flange 41 and the bottom surface 30c of the fitting groove portion 30a; the gaps serve as clearances for housing part of the seal member 30 (the outward projections 30b and the surrounding portions) elastically deformed by pressure when the thermostat device 101 is incorporated into the cooling circuit. Furthermore, the cutout portions 41a are provided aligned with the outward projections 30b.

[0074] Accordingly, the mounting work of the thermostat device 101 to the cover member 2 or the housing 3, which form the flow passage for the cooling water, can be facilitated. Thus, the assembly work when the thermostat device 101 is incorporated into the cooling circuit of the automobile can be facilitated. In the thermostat device 101 of the present embodiment, the load applied during press fitting can be reduced. Thus, mounting work-related failures, such as defective sealing due to turning up of the seal member or damage due to compression cracking, can be significantly reduced.

[0075] <Modification of Second Embodiment>

[0076] Subsequently, a modification of the thermostat device of the second embodiment will be described in detail with reference to the drawings. As described above, in the thermostat device 101 of the second embodiment, the plurality of cutout portions 41a are intermittently provided on the outer circumferential edge 41b of the flange 41, and the seal member 30 is fitted into the flange 41 so that the positions of the cutout portions 41a and the outward projections 30b coincide, so that the press-fitting of the flange 41 with the seal member 30 fitted therein into the mounting groove portion 2a can be facilitated (see FIGS. 7(b), 7(c), and 8).

[0077] The modification further aims to facilitate the operation of fitting the cutout portion 41a aligned with the position of the outward projection 30b' (see FIG. 8).

[0078] FIG. 9 is a view showing the modification of the thermostat device of the second embodiment. (a) is a perspective view, and (b) is a plan view. FIG. 10 is a view showing the appearance of a seal member used in the modification, and (a) is a perspective view and (b) is a schematic view of the seal member as viewed from a side surface side.

[0079] A thermostat device 101' in the present modification has the same structure as thermostat device 101, except for the shape of the seal member. In the present modification, for example, positioning is performed using the jiggle valve 41c, or an auxiliary air vent valve (see FIG. 9), when the seal member 30' is fitted into the flange 41. Thus, the fitting of the seal member 30' into the flange 41 is made easier.

[0080] In the above-described thermostat device 101 of the second embodiment, for convenience of description, the jiggle valve 41c is not particularly mentioned. However, similarly, a jiggle valve (not shown) functions as an auxiliary valve for the air vent. In the present modification, as an example, a case where twelve of the outward projections 30b' of the seal member 30' are provided at equal intervals (in the thermostat device 101 of the second embodiment, eight outward projections 30b are provided as an example) is described. Therefore, in the thermostat device 101' with the seal member 30' fitted therein shown in FIG. 9(a), twelve cutout portions 41a are provided at equal intervals, and, similar to the second embodiment, it is assumed that the positions of the cutout portion 41a and the outward protrusion 30b' coincide (see FIG. 8 for the state in which the seal member 30' is fitted in the flange 41).

[0081] The seal member 30' used in the present modification is an annular rubber ring (see FIG. 10(a)) similar to that in the second embodiment. The fitting groove portion 30a for fitting to cover the upper and lower surfaces of the outer circumferential portion (the outer circumferential edge 41b and the surrounding portions) of the flange 41 is formed over the entire circumference on the inner circumferential surface.

[0082] On the outer circumferential surface of the seal member 30', the outward projections 30b' that can support the thermostat device 101' by an elastic force are provided as locking means. In the present modification, as described above, twelve outward projections 30b' are provided at equal intervals. Furthermore, as shown in FIG. 10(b), the adjacent outward projections 30b' are alternately disposed on the upside of the outer circumferential surface and the downside of the outer circumferential surface of the seal member 30' as viewed from the side surface side. In other words, the outward projections 30b' are disposed on the outer circumferential surface of the seal member 30' to be distributed at the cover member 2 side (corresponding to the upside of the outer circumferential surface) and the housing 3 side (corresponding to the downside of the outer circumferential surface) when the cover member 2 and the housing 3 sandwich the flange 41. Here, for convenience, the outward projections 30b' provided on the cover member 2 side are referred to as the upper outward projections 30d, and the outward projections 30b' provided on the housing 3 side are referred to as the lower outward projections 30e.

[0083] By providing these outward projections 30b' (upper outward projection 30d, lower outward projection 30e), when the flange 41 with the sealing member 30' inserted is press-fitted into the mounting groove portion 2a of the cover member 2 together with the outward projections 30b', the upper outward projection 30d contacts the inner circumferential surface 2b of the mounting groove portion 2a (see FIG. 1(c)) while maintaining elasticity (elastic contact), and the annular side surface of the sealing member 30' abuts against the upper surface 2c of the mounting groove portion 2a (see FIG. 1(c)). Here, the upper outward projections 30d are elastically deformed under pressure and the seal member 30' is locked to the inner circumferential surface 2b by the restoration elasticity (reaction force), The thermostat device 101' is supported by the elastic force against the inner circumferential surface 2b of the mounting groove portion 2a. preventing it from falling off when the hand is released. In other words, the thermostat device 101' can be stably locked to the cover member 2, even before it is sandwiched between the cover member 2 and the housing 3, and fastened and integrated.

[0084] In the present modification, as an example, the upper outward projections 30d and the lower outward projections 30e are alternately provided. However, for example, when the mounting groove portion 2a is provided in the inner circumference of the lower end opening in the cover member 2, the outward projections 30b' that function for fall prevention in the thermostat device 101' shown in FIG. 9(a) are the upper outward projections 30d (the outward projections 30b' at the cover member 2 side), and the gaps that function to suppress the load applied during the press fitting are those formed by the cutout portions 41a that correspond to the upper outward projections 30d. In this case, though the lower outward projections 30e do not function for fall prevention or suppression of the load applied during press fitting, the upper outward projections 30d and the lower outward projections 30e are alternately provided, so the same effects are achieved without paying attention to the surfaces (front and back surfaces) of the annular seal member 30'. In other words, it does not matter which surface of the annular seal member 30' is attached to the cover member 2 side.

[0085] Conversely, when the fitting groove portion is provided on the housing 3 side, the outward projections 30b' that function to prevent falls in the thermostat device 101' shown in FIG. 9(a) are the lower outward projections 30e (the outward projections 30b' at the housing 3 side), as opposed to the above description. The gaps that function to suppress the load applied during press fitting are gaps formed by the cutout portions 41a that correspond to the lower outward projections 30e.

[0086] As shown in FIGS. 9 and 10(a), a positioning mark 30f is provided on the inner circumferential surface of the seal member 30' used in the present modification. The positioning mark 30f includes two projections, for example. When the seal member 30' is fitted such that the jiggle valve 41c provided in the flange 41 is located between the two projections, the positions of the cutout portions 41a and the outward projections 30b' align automatically. Thus, aligning the positions of the cutout portions 41a and the outward projections 30b' can be simplified, thereby making the fitting work of the seal member 30' into the flange 41 easier.

[0087] In other words, by the positioning using the above-described positioning mark 30f, the positions of the cutout portions 41a of the flange 41 and the outward projections 30b' and the seal member 30' can be easily matched. Furthermore, by providing the upper outward projections 30d and the lower outward projections 30e, when the seal member 30' is fitted in the flange 41, fitting can be performed without paying attention to the surfaces (front and back surfaces) of the annular seal member 30'.

[0088] The above-described positioning mark 30f is not limited thereto, but can be any shape and structure. In the present modification, as an example, the positioning mark 30f is formed by the two projections. However, as long as the positioning mark 30f can implement positioning that matches the positions of the cutout portions 41a and the outward projections 30b', for example, a sign or a figure as a mark may be stamped on the seal member 30'.

[0089] As shown in FIG. 11 (the outward projections 30b' are omitted in the drawing), when the seal member 30' is provided to overlap the jiggle valve 41c, a cutout may be provided in the seal member 30' so as to avoid the jiggle valve 41c. Accordingly, the cutout portion can be used as a positioning mark (positioning mark 30f).<Third Embodiment>

[0090] Subsequently, a thermostat device of a third embodiment will be described with reference to the drawings. This embodiment does not limit the scope of the invention. Furthermore, the elements that can be described in the same manner as those of the above-described first embodiment may have the same signs, and the overlapping descriptions thereof may be omitted. The configurations of the cooling circuit shown in FIGS. 1 and 2 are the same as those of the above-described first embodiment.<Thermostat Device>

[0091] FIG. 12 shows an example of a configuration of the thermostat device of the third embodiment, (a) is a cross-sectional view of a thermostat device 102 before attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B3-B3', and (c) is an enlarged view of a portion F. The thermostat device 102 of the present embodiment differs from the thermostat device 1 of the first embodiment only in the structure of the seal member (hereinafter, referred to as a seal member 51).

[0092] Therefore, the descriptions of "Configuration of Thermostat Device" and "Assembly Method" other than the above description are similar to those in the first embodiment described above, and it can be described by replacing the thermostat device 1 with the thermostat device 102 and the seal member 30 with the seal member 51, respectively.<Details of Seal Member 51>

[0093] Subsequently, the shape and structure of the seal member 51 to be used for the thermostat device 102 of the present embodiment will be described in detail with reference to the drawings.

[0094] FIG. 13 shows a cross-section of the seal member 51 along line B3-B3' to be used in the thermostat device 102 of the present embodiment (see FIG. 12(a)). FIG. 14 is a schematic diagram showing a state in which the seal member 51 is fitted into the flange 24. The appearance (a front view, a side view, and a perspective view) of the seal member 51 is the same as the seal member 30 used in the thermostat device 1 of the above-described first embodiment (see FIG. 5).

[0095] As shown in FIG. 5, the seal member 51 to be used in the thermostat device 102 of the present embodiment is an annular rubber ring with a tapered shape that narrows toward the outer circumference, and a fitting groove portion 51a for fitting to cover the upper and lower surfaces of the outer circumferential portion of the flange 24 is formed over the entire circumference on the inner circumferential surface. The seal member 30 used in the first embodiment and the seal member 51 to be used in the present embodiment are different only in the internal structure of the fitting groove portion.

[0096] Specifically, as shown in FIGS. 13 and 14, a plurality of ribs 51c having a convex shape projecting toward the flange 24 is provided on a bottom surface 51b of the fitting groove portion 51a to be in contact with the outer circumferential edge 24b when the flange 24 is fitted in the seal member 51. Accordingly, a gap 52 is formed as the above-described specific gap between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a excluding the ribs 51c. It is preferable that the ribs 51c are disposed at positions that deviate from the positions of the respective outward projections 30b. The ribs 51c are provided at those positions, and thus, when the flange 24 with the seal member 51 fitted therein is press-fitted in the mounting groove portion 2a, the gap 52 functions as a "clearance (play)" of the outward projections 30b and surrounding portions thereof elastically deformed by pressure, and the load applied during press fitting can be suppressed. Accordingly, the mounting work of the thermostat device 102 to the cover member 2 is facilitated, achieving the same effect as the first embodiment.

[0097] Since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member 51, damage due to compression cracking, can be significantly reduced.

[0098] Other than the recitation of the internal structure of the fitting groove portion 51a and the formation of the gap 52, the description of <Details of Seal Member 51> is similar to <The Details of seal Member 30> in the first embodiment described above. It can be described by replacing thermostat device 1 with thermostat device 102 and seal member 30 with seal member 51, respectively<Advantageous Effects>

[0099] As described above, in the thermostat device 102 of the present embodiment, the gap 52, which is a clearance for housing a part of the seal member 51 (the outward projections 30b and the surrounding portions) elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit, is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a other than the ribs 51c. It is preferable that the ribs 51c are positioned in locations that deviate from the positions of the respective outward projections 30b.

[0100] Accordingly, the mounting work of the thermostat device 102 to the cover member 2 forming the flow passage of the cooling water or the housing 3 can be made easier, and thus the assembly work when the thermostat device 102 is incorporated into the cooling circuit of the automobile can be made easier. In the thermostat device 102 of the present embodiment, since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member, damage due to compression cracking, can be significantly reduced.<Third Embodiment: First Modification>

[0101] In the above-described third embodiment, the ribs 51c are positioned in locations that deviate from the positions of the respective outward projections 30b, however, the invention is not limited to that. For example, as a first modification of the above-described seal member 51, the ribs 51c may be disposed aligned with the respective outward projections 30b provided in the seal member 51. FIG. 15 shows a cross-section along line B-B' of the seal member 51 in the first modification. FIG. 16 is a schematic diagram showing a state in which the seal member 51 of the first modification is fitted in the flange 24. Also, in the first modification, the gap 52 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a, other than the ribs 51c.

[0102] The first modification is effective, for example, when the hardness of the used seal member (for example, the hardness is about 60) is lower than the hardness of a seal member generally used (for example, the hardness is about 70), and the more deformable seal member is used. By providing the ribs 51c at the positions in FIGS. 15 and 16, when the flange 24 with the seal member 51 fitted therein is press-fitted in the mounting groove portion 2a, the gap 52 formed at the position deviated from the positions of the respective outward projections 30b functions as a "clearance (play)" of the outward projections 30b elastically deformed by pressure, the ribs 51c, and the surrounding portions, and thus the load applied during press fitting can be suppressed.<Third Embodiment: Second Modification>

[0103] In the third embodiment described above, a plurality of ribs 51c were provided based on the position of each outward protrusion 30b. However, it is also possible to provide the plurality of ribs 51c without using the position of the outward protrusions 30b as a reference. Specifically, instead of the outward projections 30b above described, an annular outward projection (not shown) as locking means may be provided over the entire circumference on the outer circumferential surface of the seal member 51. In addition, a plurality of ribs 51c having a convex shape may be provided in any position on the bottom surface 51b of the fitting groove portion 51a. Also, in the modification, the gap 52 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a, excluding the ribs 51c.<Fourth Embodiment>

[0104] Subsequently, a thermostat device of a fourth embodiment will be described with reference to the drawings. This embodiment does not limit the scope of the invention. Furthermore, the elements that can be described in the same manner as those of the above-described first embodiment may have the same signs, and the overlapping descriptions thereof may be omitted. The configurations of the cooling circuit shown in FIGS. 1 and 2 are the same as those of the above-described first embodiment.<Thermostat Device>

[0105] FIG. 17 shows an example of a configuration of the thermostat device of the fourth embodiment, (a) is a cross-sectional view of a thermostat device 103 before attached to the cover member 2 and the housing 3, and (b) is an enlarged view of the portion G. The thermostat device 103 of the present embodiment differs from the thermostat device 1 of the first embodiment in the appearance shape of the seal member (hereinafter, referred to as a seal member 61) and the depth of the fitting groove portion (hereinafter, referred to as a fitting groove portion 61a).

[0106] Therefore, other than the above description, the descriptions of <Configuration of Thermostat Device> and <Assembly Method> are similar to those in the first embodiment described above, and they can be described by replacing the thermostat device 1 with the thermostat device 103 and the seal member 30 with the seal member 61, respectively.<Details of Seal Member 61>

[0107] Subsequently, the shape and structure of the seal member 61 used for the thermostat device 103 of the present embodiment will be described in detail with reference to the drawings.

[0108] FIG. 18 is a view showing an example of the shape of the seal member 61; (a) is a perspective view, and (b) is an enlarged view of the portion H.

[0109] For example, as shown in FIGS. 17 and 18, the seal member 61 to be used in the thermostat device 103 of the present embodiment is an annular rubber ring with a tapered shape that narrows toward the outer circumference, and the fitting groove portion 61a for fitting to cover the upper and lower surfaces of the outer circumferential portion of the flange 24 is formed over the entire surface on the inner circumferential surface. In the present embodiment, as an example, the seal member 61 is the annular rubber ring with a tapered shape that narrows toward the outer circumference. However, the invention is not limited to that. For example, any shape that can seal the cooling water such as an annular rubber ring formed by parallel opposing surfaces (upper surface and lower surface) may be adopted.

[0110] In the present embodiment, the gap 34 formed in the above-described first embodiment is not provided. As shown in FIG. 17(b), the outer circumferential edge 24b of the flange 24 and the bottom surface 61b of the fitting groove portion 61a are in contact along the entire circumference. In other words, the depth of the fitting groove portion differs from that of the seal member 30 in the first embodiment.

[0111] The seal member 61 to be used for the thermostat device 103 of the present embodiment has a specific gap to house part of the seal member that is elastically deformed by pressure when the thermostat device is incorporated into the cooling circuit.

[0112] Specifically, as shown in FIG. 18, clearance grooves 61c as the specific gaps described above are intermittently provided, and the clearance grooves 61c are respectively provided on the surface of the upside (hereinafter, referred to as an upper surface) or the surface of the downside (hereinafter, referred to as a lower surface) of the seal member 61. In other words, each clearance groove 61c is provided on one of the two opposing surfaces (upper surface, lower surface) formed from the outer circumferential edge toward the inner circumferential portion of the sealing member 61. In the present embodiment, as an example, eight outward projections 30b are provided on the outer circumferential surface of the seal member 61 (see FIG. 18(a)), and eight clearance grooves 61c are individually provided around these outward projections 30b. Furthermore, in the present embodiment, when the seal member 61 is fitted in the flange 24, at least one clearance groove 61c is located on the underside of the outward projection 30b (see FIG. 17).

[0113] By providing the clearance grooves 61c are provided as described above, when the flange 24 with the seal member 61 fitted therein is press-fitted into the mounting groove portion 2a, the gaps by the clearance grooves 61c function as "clearances (plays)" of the outward projections 30b elastically deformed by pressure and the surrounding portions, and the load applied during press fitting can be suppressed. Accordingly, similar to the effect of the first embodiment, the mounting work of the thermostat device 103 to the cover member 2 is facilitated.

[0114] Since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member 61, damage due to compression cracking, can be significantly reduced.

[0115] For example, when the clearance grooves are formed over the entire circumference of the outer circumferential surface of the seal member, the volume of the seal member becomes smaller (the volume of the gaps as the clearances of the elastically deformed outward projections 30b is larger), and consequently, the sealing power may decrease when the seal member is sandwiched between the cover member 2 and the housing 3. In contrast, as described in the present embodiment, when the clearance grooves 61c are intermittently formed, the reduction in volume of the seal member 61 due to the formation of the clearance grooves 61c is suppressed, and consequently, the sealing power can be sufficiently secured when the seal member 61 is sandwiched between the cover member 2 and the housing 3.

[0116] Note that the seal member 61 may be provided with all of the clearance grooves 61c on the same surface side (the upper surface side or the lower surface side). However, in this case, when the seal member 61 is fitted into the flange 24, the seal members 61 are fitted while individually checking orientation so that the clearance grooves 61c are on the lower side of the outward projections 30b (see FIG. 17). Accordingly, from the viewpoint of ease of operation when fitting the seal member 61 to be used in the thermostat device 103 of this embodiment into the flange 24, it is preferable that the adjacent clearance grooves 61c do not locate on the same surface side (upper or lower) as much as possible. Accordingly, the clearance grooves 61c are distributedly disposed on both surfaces of the seal member 61. Approximately half of the clearance grooves 61c are located on the underside of the outward projections 30b without regard to the orientation of the seal member 61, and thus allowing the seal member 61 to be easily fitted into the flange.

[0117] In the present embodiment, as an example, the outward projections 30b are intermittently provided as in the other embodiment. However, the outward projections 30b are not necessarily intermittent. For example, the outward projections 30b may be formed annularly over the entire circumference of the outer circumferential surface of the seal member 61. When the outward projections 30b may be formed on the entire outer circumference surface of the seal member 61, the clearance grooves 61c function as clearances (plays) during press fitting when the clearance grooves 61c are intermittently formed (for example, when the eight clearance grooves 61c are intermittently formed as described above).

[0118] Other than the description of the appearance of the seal member 61 (clearance grooves 61c), the depth of the fitting groove portion 61a, and the formation of the gaps described above, the description of <Details of Seal Member 61> is similar to that of <Details of Seal Member 30> in the first embodiment described above, and it can be described by replacement of the thermostat device 1 with the thermostat device 103 and the seal member 30 with the seal member 61, respectively.<Advantageous Effects>

[0119] As described above, in the thermostat device 103 of the present embodiment, the seal member 61 is provided with clearance grooves as gaps intermittently, and each of the clearance grooves is provided on one side surface of two opposing surfaces formed from the outer circumferential edge toward the inner circumferential portion of the seal member 61. When a plurality of outward projections 30b are provided on the outer circumferential surface of the seal member 61, the seal member 61 is provided with the clearance grooves 61c around the outward projections 30b on one side surface of the two opposing surfaces formed from the outer circumferential edge to the inner circumferential portion.

[0120] Accordingly, the mounting work of the thermostat device 103 to the cover member 2 forming the flow passage of the cooling water or to the housing 3 can be facilitated, and thus the assembly work can be facilitated when the thermostat device 103 is incorporated into the cooling circuit of the automobile. In the thermostat device 103 of the present embodiment, since the load applied during press fitting can be reduced, mounting work-related failures, such as defective sealing due to turning up of the seal member, damage due to compression cracking, can be significantly reduced.

[0121] Furthermore, in the present embodiment, since the clearance grooves 61c are intermittently formed, the volume reduction of the seal member 61 due to the formation of the clearance grooves 61c can be suppressed. As a result, the sealing power when the seal member is sandwiched between the cover member 2 and the housing 3 can be sufficiently secured.

[0122] Although not explicitly mentioned in the description of the respective embodiments, the respective embodiments and modifications except the first modification of the third embodiment are effective when, for example, the hardness of the used seal member is not lower than the hardness of a seal member generally used (for example, with a hardness of about 70) or relatively harder, the seal member which is harder to deform is used.

[0123] The shapes and structures of the thermostat devices of the first to fourth embodiments are not limited to the shapes and structures of the thermostat devices of the above-described respective embodiments, and alterations, changes can be appropriately made to the shapes and structures of the respective portions according to the specifications, the usage environments of the devices.Reference Signs List

[0124] 1, 101, 101', 102, 103 thermostat device 2 cover member 2a fitting groove portion 2b inner circumferential surface 2c upper surface 3 housing 4 first inflow port 5 second inflow port 6 third inflow port 7 outflow port 11 thermo-operating unit 12 relief operating unit 21 control valve 21a first spring seat portion 22 relief valve 23 frame 23a second spring seat portion 23b cylindrical portion 24, 41 flange 24a piston lock portion 24b outer circumferential edge 25, 42 outer shell portion 26 thermo-element 27 piston rod 28, 33 valve seat 29 coil spring 30, 30', 51, 61 seal member 30a, 51a, 61a fitting groove portion 30b, 30b' outward projection 30c, 51b, 61b bottom surface 30d upper outward projection 30e lower outward projection 30f positioning mark 31 relief rod 32 coil spring 34, 52 gap 41a cutout portion 41b outer circumferential edge 41c jiggle valve 51c rib 61c clearance groove

Examples

first embodiment

[0021]First, a thermostat device of a first embodiment will be described in detail with reference to the drawings. For convenience of description, upward and downward directions in the drawings are referred to as "upper" and "lower".

[0022]FIG. 1 shows an example of a state in which the thermostat device according to the invention is incorporated therein into a cooling circuit of an automobile, FIG. 1(a) is a plan view, FIG. 1(b) shows a cross-section along line A-A', and FIG. 1(c) is an enlarged view showing a cross-section of a cover member along line A-A'. FIG. 2 is a view showing an exploded configuration of a flow passage of cooling water including the thermostat device. A thermostat device 1 of the present embodiment is disposed within the cooling circuit of the automobile for circulating the cooling water between an engine and a radiator. As shown in FIGS. 1 and 2, the thermostat device 1 is sandwiched between a cover member 2 forming the flow passage of the cooling water and ...

second embodiment

[0061]FIG. 7 shows an example of a configuration of the thermostat device of the (a) is a cross-sectional view of a thermostat device 101 before attached to the cover member 2 and the housing 3, (b) is a cross-sectional view along line B2-B2', and (c) is an enlarged view of a portion E.

[0062]The thermostat device 101 of the present embodiment is a thermostat device having a relief function like that of the above-described first embodiment, but different from that of the first embodiment only in the shape of the flange (hereinafter, referred to as a flange 41). That is, the thermostat device 101 of the present embodiment is integrally formed, in which the thermo-operating unit 11 is housed within an outer shell portion 42 formed by the frame 23 and the flange 41 and the relief operating unit 12 is fixedly bonded to one end side in the longitudinal direction of the thermo-operating unit 11 (the lower end portion of the thermo-element 26) (see FIG. 7(a)).

[0063]Furthermore, as shown in...

third embodiment

[0101]In the above-described third embodiment, the ribs 51c are positioned in locations that deviate from the positions of the respective outward projections 30b, however, the invention is not limited to that. For example, as a first modification of the above-described seal member 51, the ribs 51c may be disposed aligned with the respective outward projections 30b provided in the seal member 51. FIG. 15 shows a cross-section along line B-B' of the seal member 51 in the first modification. FIG. 16 is a schematic diagram showing a state in which the seal member 51 of the first modification is fitted in the flange 24. Also, in the first modification, the gap 52 is formed between the outer circumferential edge 24b of the flange 24 and the bottom surface 51b of the fitting groove portion 51a, other than the ribs 51c.

[0102]The first modification is effective, for example, when the hardness of the used seal member (for example, the hardness is about 60) is lower than the hardness of a seal...

Claims

1. A thermostat device which comprises a thermo-element incorporating a thermal expansion material that expands and contracts in response to the temperature of cooling water, a control valve attached to the thermo-element, a piston rod that advances and retracts due to the expansion and contraction of the thermal expansion material, a flange forming a valve seat on which the control valve seats at an inner circumferential portion, where the thermostat device operates such that the control valve opens and closes due to movement of the thermo-element caused by advance and retraction of the piston rod, and is incorporated into the cooling circuit by sandwiching the flange between a cover member and a housing that form the cooling water flow passage, comprising: a seal member with an annular shape attached to the outer circumferential portion including the outer circumferential edge and the surrounding portions of the flange and sealing the connecting portion between the cover member and the housing, wherein the sealing member has a fitting groove portion formed on its inner surface to cover the outer circumferential edge portion of the flange, and outwardly projecting portions on its outer surface, and a specific gap as a clearance is formed to accommodate a portion of the sealing member that elastically deforms under the pressing force when the thermostat device is incorporated into the cooling circuit.

2. The thermostat device according to claim 1, wherein the gap is formed between an outer circumferential edge of the flange and a bottom surface of the fitting groove portion.

3. The thermostat device according to claim 1, wherein a plurality of the outward projections are provided on the outer circumferential surface of the seal member, a cutout portion is provided in a part of the outer circumferential edge of the flange, the gap is formed between an outer circumferential edge of the cutout portion of the flange and the bottom surface of the fitting groove portion, and the cutout portion is provided aligned with the outward projection.

4. The thermostat device according to claim 3, wherein adjacent outward projections are disposed on the outer circumferential surface of the seal member to be distributed on the cover member side and the housing side when the flange is sandwiched between the cover member and the housing.

5. The thermostat device according to claim 3, wherein when a jiggle valve as an auxiliary valve is provided in the flange, the seal member has a positioning mark on an inner circumferential surface thereof, and the positioning mark is provided to align the cutout portion with the outward projection when the seal member is fitted with reference to the position of the jiggle valve.

6. The thermostat device according to claim 1, wherein a plurality of the outward projections are provided on the outer circumferential surface of the seal member, a plurality of ribs, brought into contact with the outer circumferential edge of the outer circumferential portion when the outer circumferential portion of the flange is fitted in the seal member, are provided on a bottom surface of the fitting groove portion, and the gap is formed between the outer circumferential edge of the flange and a bottom surface of the fitting groove portion except for the locations of the ribs.

7. The thermostat device according to claim 6, wherein the ribs are disposed at positions deviated from the positions of the outward projections.

8. The thermostat device according to claim 6, wherein the ribs are disposed in alignment with the outward projections.

9. The thermostat device according to claim 1, wherein clearance grooves as the gaps are intermittently provided in the seal member, each clearance groove is provided on one side surface of two opposing surfaces formed from an outer circumferential edge toward an inner circumferential portion of the seal member.

10. The thermostat device according to claim 9, wherein a plurality of the outward projections are provided on the outer circumferential surface of the seal member, and the clearance grooves are provided around the outward projections.

11. The thermostat device according to claim 9 or 10, wherein the adjacent clearance grooves are provided on different surface sides.

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