Thermostat device

Abstract

To provide a thermostat device which easily allows dimensional tolerance of components and enables easy assembly, attachment, and replacement and in which a thermostat and a differential pressure regulating valve are integrated.SOLUTION: A thermostat device 1 includes: a thermostat 10 for opening and closing a main passage; a differential pressure regulating valve 20 for opening and closing a bypass passage; and a connection unit 26 which connects the thermostat 10 with the differential pressure regulating valve 20. The connection unit 26 includes: a holder 27 fixed to an inner periphery of a second valve seat member 21 of the differential pressure regulating valve 20; a flange 27b protruding outward from the holder 27; an engagement part 19a which is provided at a frame 19 of the thermostat 10 and on which the flange 27b hooks; and a holder biasing member 18 which biases the holder 27 in a direction such that hooking of the flange 27b on the engagement part 19a is maintained.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a thermostat device, and more particularly to a thermostat device in which a thermostat and a differential pressure valve are connected. [Background technology]

[0002] The engine coolant circuit disclosed in Patent Document 1 includes a main passage that circulates engine coolant via a radiator, a bypass passage that bypasses the radiator and is connected in parallel to the main passage, a thermostat installed at the branch point of both passages, and a car heater passage that bypasses the radiator and is connected in parallel to the main passage. The thermostat includes a main passage opening / closing valve and a bypass passage opening / closing valve that selectively open the main passage and the bypass passage by detecting the temperature of the coolant.

[0003] A flow control valve is further connected integrally to the thermostat. When the bypass passage opening / closing valve is in a position to open the bypass passage, the opening degree of the flow control valve is determined by the balance between the urging force of a spring that urges the valve port facing the inlet of the bypass passage in a direction to close the valve port from the bypass passage side and the coolant pressure.

[0004] In order to integrate the flow control valve with the thermostat, a rod is fixed to the bottom wall of the wax-filled pellet body of the thermostat by welding or adhesive, and the rod is fitted into the center hole of the flow control valve. Then, the flow control valve is guided by the rod and made movable up and down within a case fixed to the bottom of the cylindrical case of the thermostat by welding, etc. However, this structure has a problem in that it is difficult to allow for the dimensional tolerances of each part. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Jpn. Jpn. Published No. 62-15470 Summary of the Invention [Problem to be solved by the invention]

[0006] One object of the present invention is to provide a thermostat device which integrates a thermostat and a differential pressure valve, which can easily tolerate dimensional tolerances of parts, is easy to assemble, and can be easily attached to and replaced in a main passage and a bypass passage. [Means for solving the problem]

[0007] One aspect of the present invention is a thermostat device to be mounted at a branch point between a main passage and a bypass passage, the thermostat comprising: a thermostat for opening and closing the main passage; a differential pressure valve for opening and closing the bypass passage; and a connecting unit for connecting the thermostat and the differential pressure valve. The thermostat comprises a first valve seat member having a first opening for communicating with the main passage, a first valve body that opens and closes the first opening by seating on and off the first valve seat member, a valve stem to which the first valve body is fixed, a temperature sensing unit that is fixed to a base end of the valve stem and is filled with a material that expands or contracts depending on temperature, and a piston that protrudes from a tip of the valve stem and moves forward and backward depending on the expansion or contraction of the material; and a thermoelement that biases the first valve body in a closing direction. the differential pressure valve comprises a second valve seat member having a second opening formed therein for communicating with the bypass passage, a second valve body that opens and closes the second opening by being seated on and released from the second valve seat member, a second biasing member that biases the second valve body in a closing direction, and a support member that is fixed to the second valve seat member and supports the second biasing member; and the connecting unit comprises a holder that has a communication hole on a side surface and has the second valve seat member fixed to its inner periphery, a flange that protrudes outward from the holder, an engaging portion that is provided on the frame and on which the flange is hooked, and a holder biasing member that biases the holder in a direction that maintains the flange hooked on the engaging portion.

[0008] In the thermostat device, the holder biasing member may be the first biasing member that presses the flange protruding from the holder, and biases it in a direction to maintain the flange hooked on the engagement portion.

[0009] In the thermostat device, the holder biasing member may be a third biasing member different from the first biasing member and the second biasing member, which is sandwiched and compressed between the frame and the holder.

[0010] The thermostat device may further include an auxiliary passage that constantly communicates from the main passage to the bypass passage when the thermostat device is installed.

[0011] The auxiliary passage may be a gap between an inlet of the bypass passage and the holder inserted into the inlet.

[0012] The auxiliary passage may be a gap of the second opening that is not closed by the second valve body when the second valve body is seated on the second valve seat member.

[0013] The present invention is not limited to the above objects or aspects. A more complete understanding of the present invention and many of the advantages thereof will become more readily apparent from the following detailed description taken in conjunction with the associated drawings. [Brief description of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a thermostat device according to a first embodiment of the present invention, which is attached to a branch point between a main passage and a bypass passage. [Diagram 2] FIG. 2 is a cross-sectional view of the differential pressure valve of the first embodiment when the valve is open. [Diagram 3] 1A is a diagram showing a method for assembling the differential pressure valve of the first embodiment, FIG. 1B is a diagram showing a method for assembling the thermostat device of the first embodiment, and FIG. 1C is a perspective view of the assembled thermostat device of the first embodiment. [Figure 4] FIG. 5 is a cross-sectional view of a thermostat device according to a second embodiment of the present invention, which is mounted at a branch point between a main passage and a bypass passage. [Diagram 5] FIG. 11 is a cross-sectional view of the differential pressure valve of the second embodiment when the valve is open. [Figure 6] 1A is a diagram showing a method for assembling the differential pressure valve of the second embodiment, FIG. 1B is a diagram showing a method for assembling the thermostat of the second embodiment, FIG. 1C is a diagram showing a method for assembling the thermostat device of the second embodiment, and FIG. 1D is a perspective view of the assembled thermostat device of the second embodiment. [Figure 7] 7A is a perspective view of a thermostat device according to another embodiment of the present invention, and FIG. 7B is a cross-sectional view of the thermostat device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [First Example] A thermostat device 1 according to a first embodiment of the present invention will be described with reference to Figs. 1 to 3. The terms "upper", "lower", "left" and "right" used in the description of each embodiment of the present invention are used for convenience to refer to the terms "upper", "lower", "left" and "right" in the drawings referred to in the description. The thermostat device 1 is used by being attached to a passage through which a coolant flows to cool an engine of an automobile or the like. In Fig. 1, the thermostat device 1 is attached to a branch point on the outlet side of the engine between a main passage 2, 2a that circulates the coolant between the engine and the radiator, and a bypass passage 3 that bypasses the radiator and is connected in parallel to the main passage 2a. The outline arrows in Fig. 1 indicate the direction in which the coolant flows in the passage 2, a partial passage 2a of the main passage 2 that extends from the branch point toward the radiator, and the bypass passage 3.

[0016] The thermostat device 1 includes a thermostat 10 for opening and closing the main passages 2, 2a, a differential pressure valve 20 for opening and closing the bypass passage 3, and a connecting unit 26 for connecting the thermostat 10 and the differential pressure valve 20.

[0017] The thermostat 10 will now be described. The thermostat 10 comprises a first valve seat member 11 in which a first opening 11a for communicating with the main passages 2, 2a is formed, a first valve body 12 that opens and closes the first opening 11a by being seated on and removed from the first valve seat member 11, a valve stem portion 13 to which the first valve body 12 is fixed, a thermoelement 16 having a temperature sensing portion 14 that is fixed to the base end of the valve stem portion 13 and in which a material that expands or contracts according to temperature is enclosed, and a piston 15 that protrudes from the tip of the valve stem portion 13 and moves forward and backward according to the expansion or contraction of the material, a first biasing member 18 that biases the first valve body 12 in a closing direction, and a frame 19 that is fixed to the first valve seat member 11 and supports the first biasing member 18.

[0018] The first valve seat member 11 includes a cylindrical portion 11b having the first opening 11a on its inner circumference, and an annular portion 11c protruding outward from the cylindrical portion 11b. When the first valve body 12 is seated on the annular portion 11c of the first valve seat member 11, the first opening 11a is closed and the cooling liquid does not flow from the main passage 2 to the partial passage 2a. When the first valve body 12 is separated from the annular portion 11c, the first opening 11a is opened and the cooling liquid flows from the main passage 2 to the partial passage 2a of the main passage 2 through the first opening 11a.

[0019] The first valve body 12 is passed through and fixed to the valve shaft portion 13. The material sealed inside the temperature sensing portion 14 is made of wax or the like which senses the temperature of the cooling water around the temperature sensing portion 14 and expands when the temperature rises and contracts when the temperature drops. The piston 15 passes through the valve shaft portion 13 in the axial direction. As the material expands or contracts, the piston 15 advances and retreats, thereby expanding or contracting the length of the portion of the piston 15 protruding from the tip of the valve shaft portion 13.

[0020] The piston receiver 17 is located on the central axis of the piston 15, and is supported by a pair of arms 11d extending from opposing positions of the cylindrical portion 11b of the first valve seat member 11 toward the piston receiver 17. The piston receiver 17 abuts against and presses the tip of the piston 15. When the portion protruding from the tip of the valve stem portion 13 of the piston 15 becomes longer, the first valve body 12, the valve stem portion 13, and the temperature sensor 14 move together in a direction away from the first valve seat member 11. On the other hand, when the protruding portion of the piston 15 becomes shorter, the first valve body 12, the valve stem portion 13, and the temperature sensor 14 move together in a direction approaching the first valve seat member 11.

[0021] The first biasing member 18 is, for example, a coil spring. One end of the first biasing member 18 presses the first valve body 12 in a direction to close the first opening 11a from the branch point side. The temperature sensing portion 14 of the thermo-element 16 is inserted into the first biasing member 18.

[0022] The frame 19 includes an annular bottom 19a supporting the other end of the first biasing member 18, a bottom opening 19b opening to the inside of the bottom 19a, and a pair of pillars 19c extending upward from opposing positions on the bottom 19a and fixed to the annular portion 11c of the first valve seat member 11. The inside and outside of the frame 19 are communicated with each other by an opening formed between the pair of pillars 19c and the bottom opening 19b.

[0023] The differential pressure valve 20 will be described. The differential pressure valve 20 includes a second valve seat member 21 in which a second opening 21a for communicating with the bypass passage 3 is formed, a second valve body 22 that opens and closes the second opening 21a by being seated on and separated from the second valve seat member 21, a second biasing member 23 that biases the second valve body 22 in a closing direction, and a support member 24 that is fixed to the second valve seat member 21 and supports the second biasing member 23.

[0024] The second valve seat member 21 has a connection hole 21b formed in its center, and the second opening 21a formed around the connection hole 21b. The second valve body 22 is a poppet valve, has a central hole 22a, and is recessed from the outer periphery toward the central hole 21a. The second biasing member 23 is a coil spring, one end of which abuts against the second valve body 22 to press the second valve body 22 in the closing direction from the bypass passage 3 side.

[0025] When the second valve body 22 is seated on the second valve seat 21, the second opening 21a is closed, and the coolant does not flow through the second opening 21a to the bypass passage 3. When the second valve body 22 is separated from the second valve seat 21, the second opening 21a is opened, and the coolant flows through the second opening 21a to the bypass passage 3.

[0026] The support member 24 has a connecting protrusion 24a that passes through the connecting hole 21b, a second valve body guide 24b that is inserted into the central hole 22a of the valve body 22, a second biasing member guide 24c that is inserted into the second biasing member 23, and a second biasing member receiver 24d that supports the other end of the second biasing member 23, which are stacked in ascending order of outer diameter. The push nut 25 has a press-fit hole 25a in its center. The second valve seat member 21 and the support member 24 are fixed together by press-fitting the connecting protrusion 24a into the press-fit hole 25a.

[0027] The connecting unit 26 will be described. The connecting unit 26 includes a holder 27 having the second valve seat member 21 fixed to the inner periphery of a cylindrical side wall 27a, a flange 27b protruding outward from the holder 27, a bottom portion 19a of the frame 19 that is provided on the frame 19 and constitutes an engagement portion on which the flange 27b is hooked, and the first biasing member 18 that constitutes a holder biasing member that biases the holder 27 in a direction that keeps the flange 27b hooked on the bottom portion 19a that is the engagement portion.

[0028] A cylindrical side wall 27a of the holder 27 is provided with a plurality of communication holes 27c that communicate between the inside and outside of the holder 27. The second valve seat member 21 is fixed integrally to the inner circumference near the lower end of the side wall 27a of the holder 27. The upper end of the holder 27 is open, and the temperature sensor 14 can be freely inserted into the holder 27. When the temperature sensor 14 is inserted into the holder 27, a gap is present between the two, which serves as a passage through which the coolant flows.

[0029] The outer diameter of the side wall 27a of the holder 27 is approximately the same as the inner diameter of the bottom opening 19b of the frame 19. The outer diameter of the annular flange 27b protruding outward near the upper end of the holder 27 is larger than the inner diameter of the bottom opening 19b of the frame 19. The holder 27 inserted into the bottom opening 19b is supported by the frame 19 as the flange 27b gets caught on the bottom 19a of the frame 19, i.e., the engagement portion.

[0030] The first biasing member 18 constituting the holder biasing member presses the flange 27b protruding from the holder 27, biasing it in a direction that keeps the flange 27b hooked on the bottom portion 19a constituting the engagement portion. The first biasing member 18 is sandwiched and compressed and held between the flange 27b supported on the bottom portion 19a of the frame 19 and the first valve body 12.

[0031] Next, a method of assembling the thermostat device 1 will be described with reference to Fig. 3. As shown in Fig. 3(a), the support member 24 is inserted through the second biasing member 23, the central hole 22a of the second valve body 22, and the connecting hole 21b of the first valve seat member 21, and then the connecting protrusion 24a is press-fitted into the press-fit hole 25a of the push nut 25. In this way, the differential pressure valve 20 is integrally formed.

[0032] As shown in Fig. 3(b) and Fig. 3(c), the holder 27 of the differential pressure valve 20 is inserted into the bottom opening 19b of the frame 19, and the flange 27b is hooked onto the engagement portion, which is the bottom 19a of the frame 19. While the first biasing member 18 is sandwiched and pressed between the flange 27b and the first valve body 12, the protrusion 19d provided at the tip of the column portion 19c of the frame 19 is inserted into the hole 11e provided in the annular portion 11c of the first valve seat member 11 and tightened. Furthermore, the gasket 28 made of an elastic material such as rubber is fitted to the outer periphery of the annular portion 11c of the first valve seat member 11. In this manner, the thermostat device 1 in which the thermostat 10 and the differential pressure valve 20 are integrated is assembled.

[0033] Next, the operation of the thermostat device 1 will be described. In Fig. 1, the thermostat device 1 is attached to the branch point of the main passage 2, through which the coolant flows from the engine coolant outlet toward the radiator, and the bypass passage 3. The thermostat 10 is installed near the entrance of a partial passage 2a of the main passage 2 that runs from the branch point toward the radiator. The gasket 28 seals the partial passage 2a and the thermostat 10.

[0034] The coolant in the main passage 2 flows into the frame 19 from the opening formed between the pair of pillars 19c, or flows into the holder 27 through the communication hole 27c, and further flows through the gap between the holder 27 and the temperature sensing part 14. Therefore, the entire temperature sensing part 14 of the thermo-element 16 can sense the temperature of the coolant.

[0035] When the differential pressure valve 20 is arranged so that the holder 27 is inserted into the inlet of the bypass passage 3, a gap exists between the inlet of the bypass passage 3 and the holder 27. The gap constitutes an auxiliary passage 29 that constantly communicates between the main passage 2 and the bypass passage 3.

[0036] By providing the auxiliary passage 29, even when the second valve body closes the second opening, the cooling liquid can always flow from the main passage 2 through the auxiliary passage 29 to the bypass passage 3. The temperature sensor 14 of the thermo-element 16 can always sense the temperature of such cooling liquid.

[0037] In addition, since it is assumed that a gap will be generated between the inlet of the bypass passage 3 and the holder 27, the holder 27 is likely to be allowed a dimensional tolerance in the outer diameter, which makes design and installation easier.

[0038] When the temperature of the coolant sensed by the temperature sensing portion 14 is lower than a predetermined temperature, the wax in the temperature sensing portion 14 contracts, and the length of the portion of the piston 15 protruding from the valve shaft portion 13 is at its smallest. In this case, the first valve body 12 is pressed by the first biasing member 18 to seat on the first valve seat member 11, the first opening 11a is closed, and the coolant does not flow from the main passage 2 to the partial passage 2a leading to the radiator.

[0039] In this case, when the pressure of the cooling liquid is extremely small, the second valve body 22 of the differential pressure valve 20 is seated on the second valve seat member 21 by the second biasing member 23 to close the second opening 21a. However, the cooling liquid in the main passage 2 flows into the bypass passage 3 through the auxiliary passage 29, which is the gap between the inlet of the bypass passage 3 and the holder 27.

[0040] 2, when the pressure of the cooling liquid increases, the second valve body 22 is pressed down against the pressing force of the second biasing member 23, and the second opening 21a opens. The valve opening of the differential pressure valve 20 is controlled to a position where the pressure of the cooling liquid and the pressing force of the second biasing member 23 are in equilibrium. The cooling liquid flows into the bypass passage 3 through the second opening 21a together with the auxiliary passage 29, so the flow rate of the cooling liquid flowing into the bypass passage 3 increases.

[0041] When the coolant reaches a predetermined temperature or higher, the wax in the temperature sensor 14 which senses the temperature expands, increasing the length of the portion of the piston 15 which protrudes from the valve shaft 13, but the tip of the piston 15 is held down by the piston receiver 17, so that the first valve body 12, the valve shaft 13 and the temperature sensor 14 move downward together. As a result, the first valve body 12 moves downward against the pressing force of the first biasing member 18, and the first opening 11a opens. As a result, the coolant which has flowed into the frame 19 flows from the first opening 11a through the opening between the pair of arms 11d to the partial passage 2a of the main passage 2 which leads to the radiator. When the opening amount of the first valve body 12 becomes large, most of the cooling water flows into the partial passage 2a, and the cooling water pressure to the differential pressure valve 20 decreases, so that the second valve body 22 seats on the second valve seat member 21 to close the second opening 21a. A part of the cooling liquid in the main passage 2 flows into the bypass passage 3 through the auxiliary passage 29.

[0042] According to the thermostat device 1, the flange 27b protruding outward from the holder 27, to which the second valve seat member 21 of the differential pressure valve 10 is fixed on the inner periphery, is caught on the engaging portion, which is the bottom 19a of the frame 19 of the thermostat 10. Furthermore, the holder biasing member, which is the first biasing member 18, presses the flange 27b and biases it in a direction to maintain the flange 27b being caught on the bottom 19a, which is the engaging portion. In this way, it is possible to obtain the thermostat device 1 in which the thermostat 10 and the differential pressure valve 20 are integrally connected, which easily tolerates dimensional tolerances of parts, is easy to assemble, and is easy to install in and replace the main passage and the bypass passage.

[0043] In addition, by modifying an existing thermostat to a frame having the shape and structure of frame 19, and further adopting the differential pressure valve 20 and connecting unit 26, it is possible to easily modify the thermostat into a thermostat device with an integrated differential pressure valve.

[0044] The thermostat device 1 is easily miniaturized because the holder biasing member is shared by the first biasing member 18 which presses the flange 27b protruding from the holder 27 in a direction to maintain the flange 27b hooked onto the engagement portion, which is the bottom 19a of the frame 19.

[0045] [Second Example] Next, a thermostat device 4 according to a second embodiment of the present invention will be described with reference to Fig. 4 to Fig. 6. In Fig. 4, the thermostat device 4 according to the second embodiment is attached to a branch point on the engine outlet side between main passages 5, 5a that circulate the coolant between the engine and the radiator, and a bypass passage 6 that bypasses the radiator and is connected in parallel to the main passage 5. The outline arrows in Fig. 4 indicate the direction in which the coolant flows in the main passage 5, the partial passage 5a of the main passage 5 that runs from the branch point toward the radiator, and the bypass passage 6.

[0046] The thermostat device 4 includes a thermostat 30 for opening and closing the main passages 5, 5a, a differential pressure valve 40 for opening and closing the bypass passage 6, and a connecting unit 45 for connecting the thermostat 30 and the differential pressure valve 40.

[0047] The thermostat 30 will now be described. The thermostat 30 comprises a first valve seat member 31 in which a first opening 31a for communicating with the main passages 5, 5a is formed, a first valve body 32 that opens and closes the first opening 31a by being seated on and removed from the first valve seat member 31, a valve stem portion 33 to which the first valve body 32 is fixed, a thermoelement 36 having a temperature sensing portion 34 that is fixed to the base end of the valve stem portion 33 and is filled with a material that expands or contracts according to temperature, and a piston 35 that protrudes from the tip of the valve stem portion 33 and moves forward and backward according to the expansion or contraction of the material, a first biasing member 38 that biases the first valve body 32 in a closing direction, and a frame 39 that is fixed to the first valve seat member 31 and supports the first biasing member 38.

[0048] The first valve seat member 31 includes a cylindrical portion 31b having the first opening 31a on its inner circumference, and an annular portion 31c protruding outward from the cylindrical portion 31b. When the first valve body 32 is seated on the annular portion 31c of the first valve seat member 31, the first opening 31a is closed and the coolant does not flow from the main passage 5 to the partial passage 5a. When the first valve body 32 is separated from the annular portion 31c, the first opening 31a is opened and the coolant flows from the main passage 5 to the partial passage 5a of the main passage 5 through the first opening 31a.

[0049] The first valve body 32 is passed through and fixed to the valve shaft portion 33. The material sealed inside the temperature sensing portion 34 is wax or the like that senses the temperature of the cooling water around the temperature sensing portion 34 and expands when the temperature increases and contracts when the temperature decreases. The piston 35 passes through the valve shaft portion 33 in the axial direction. As the material expands or contracts, the piston 35 advances and retreats, thereby expanding or contracting the length of the portion of the piston 35 protruding from the tip of the valve shaft portion 33.

[0050] The piston receiver 37 is located on the central axis of the piston 35, and is supported by a pair of arms 31d extending from opposing positions of the cylindrical portion 31b of the first valve seat member 31 toward the piston receiver 37. The piston receiver 37 abuts against and presses the tip of the piston 35. When the portion protruding from the tip of the valve stem portion 33 of the piston 35 becomes longer, the first valve body 32, the valve stem portion 33, and the temperature sensor 34 move together in a direction away from the first valve seat member 31. On the other hand, when the protruding portion of the piston 35 becomes shorter, the first valve body 32, the valve stem portion 33, and the temperature sensor 34 move together in a direction approaching the first valve seat member 31.

[0051] The first biasing member 38 is, for example, a coil spring. One end of the first biasing member 38 presses the first valve body 32 from the branch point side in a direction to close the first opening 31a. The temperature sensing portion 34 of the thermo-element 36 is inserted into the first biasing member 38.

[0052] The frame 39 includes an annular bottom 39a supporting the other end of the first biasing member 38, a bottom opening 39b opening to the inside of the bottom 39a, and a pair of pillars 39c extending upward from opposing positions on the bottom 39a and fixed to the annular portion 31c of the first valve seat member 31. The inside and outside of the frame 39 are communicated with each other by an opening formed between the pair of pillars 39c and the bottom opening 39b.

[0053] The differential pressure valve 40 will be described. The differential pressure valve 40 includes a second valve seat member 41 in which a second opening 41a for communicating with the bypass passage 6 is formed, a second valve body 42 that opens and closes the second opening 41a by being seated on and separated from the second valve seat member 41, a second biasing member 43 that biases the second valve body 42 in a closing direction, and a support member 44 that is fixed to the second valve seat member 41 and supports the second biasing member 43.

[0054] The second valve seat member 41 has a connection hole 41b formed at its center, and the second opening 41a formed around the connection hole 41b. The second valve body 42 is a poppet valve, has a central hole 42a, and is recessed from the outer periphery toward the central hole 41a. The second biasing member 43 is a coil spring, one end of which abuts against the second valve body 42 to press the second valve body 42 in the closing direction from the bypass passage 3 side.

[0055] When the second valve body 42 is seated on the second valve seat 41, the second opening 41a has a gap 41c that is not closed by the second valve body, so that the coolant flows through the gap 41c of the second opening 41a to the bypass passage 3. The gap 41c constitutes an auxiliary passage that always communicates from the main passage 5 to the bypass passage 6. As shown in FIG. 5, when the second valve body 42 is separated from the second valve seat 41, the entire second opening 41a is opened. At this time, the coolant flows through the entire second opening 41a to the bypass passage 3.

[0056] Even when the second valve body 42 is seated on the second valve seat 41, the gap 41c which constitutes the auxiliary passage exists, so that the cooling liquid always communicates from the main passage 5 to the bypass passage 6, and therefore the temperature sensor 34 can always sense the temperature of the cooling liquid.

[0057] The support member 44 has, stacked in order of smallest outer diameter, a connecting protrusion 44a that passes through the connecting hole 41b, a second valve body guide 44b that is inserted into the central hole 42a of the valve body 42, a second biasing member guide 44c that is inserted into the second biasing member 43, and a second biasing member receiver 44d that supports the other end of the second biasing member 43.

[0058] The connecting unit 45 will be described. The connecting unit 45 includes a third biasing member 46, a holder 47 having the second valve seat member 41 fixed integrally as a bottom part to the inner circumference of a cylindrical side wall 47a, a pair of pillar parts 47c extending upward from opposing positions of the side wall 47a of the holder 47, and flanges 47b protruding outward from a pair of pillar parts 47c, and an engagement part 39d protruding outward from opposing positions of the bottom part 39a of the frame 39 and having a hole into which the flange 47b is inserted and hooked. A communication hole 47d is opened between the pair of pillar parts 47c of the holder 47. The pillar parts 47c themselves also have a communication hole 47e.

[0059] The upper end of the holder 47 is open, and a lower portion of the third biasing member 46 is housed within the holder 47. The third biasing member 46 is sandwiched and compressed and held between the bottom portion 39a of the frame 39 and the bottom portion of the holder 47. The third biasing member 46 constitutes a holder biasing member that biases the holder 47 in a direction that keeps the flange 47b of the holder 47 hooked on the engagement portion 39d of the frame 39.

[0060] Next, a method of assembling the thermostat device 4 will be described with reference to Fig. 6. As shown in Fig. 6(a), the support member 44 is inserted through the second biasing member 43, the central hole 42a of the second valve body 42, and the connecting hole 41b of the second valve seat member 41 fixed integrally as the bottom of the holder 47. The second valve seat member 41 integrated with the holder 47 is fixed to the support member 44 by rolling and crimping so as to crush and widen the connecting protrusions 44a. In this manner, the differential pressure valve 40 integrated with the holder 47 is assembled.

[0061] 6(b), the first biasing member 38 is supported on the bottom 19a of the frame 19, and the temperature sensing portion 34 of the thermo-element 36 is inserted into the bottom opening 39b of the frame 39. The first biasing member 38 is sandwiched and pressed between the first valve body 32 fixed to the valve shaft portion 33 and the bottom 19a. A projection 39e provided at the tip of the column portion 39c of the frame 39 is inserted into a hole 31e provided in the annular portion 31c of the first valve seat member 31 and crimped. In this manner, the thermostat 30 is assembled.

[0062] Next, as shown in FIG. 6(c), the third biasing member 46 is sandwiched and compressed between the holder 47 integrated with the differential pressure valve 40 and the frame 39 of the thermostat 30. The pair of column parts 47c of the holder 47 are elastically deformed to insert the flanges 47b into the holes of the engagement parts 39d of the frame 39, and then the elastic deformation is released so that the hooks 47b hook onto the engagement parts 39d. The third biasing member 46, as the holder biasing member, biases in a direction to keep the hooks 47b hooked onto the engagement parts 39d. A gasket 48 made of an elastic member such as rubber is fitted to the outer periphery of the annular part 31c. In this way, the thermostat device 4 in which the thermostat 30 and the differential pressure valve 40 are integrated is assembled as shown in FIG. 6(d).

[0063] As shown in FIG. 4, when the thermostat device 4 is installed, the thermostat 30 is fixed to the partial passage 5a of the main passage 5, and the gasket 48 seals the thermostat 30 and the partial passage 5a.

[0064] The differential pressure valve 40 of the thermostat device 4 is inserted into the inlet of the bypass passage 6. The holder 47 integrated with the differential pressure valve 40 is pressed by the third biasing member 46 and grounded to the main passage 5 around the inlet of the bypass passage 6. At this time, the flange 47b is designed to be inserted into the hole of the engaging portion 39d but not in contact with the engaging portion 39d, that is, to be floating from the engaging portion 39d. Therefore, even if there is a deviation in the position of the flange 47b or the engaging portion 39d due to dimensional tolerances, this can be tolerated. Furthermore, as long as the differential pressure valve 40 is inserted into the inlet of the bypass passage 6 and the holder 47 is grounded to the main passage 5 around the inlet while being pressed by the third biasing member 46, it is possible to tolerate dimensional tolerances in the inner diameter of the inlet of the bypass passage 6 and the seating position of the holder 47, and dimensional tolerances in the outer diameter of the differential pressure valve 40 and the outer diameter and height of the holder 47.

[0065] Next, the operation of the thermostat device 4 will be described. In Fig. 4, the cooling liquid in the main passage 5 flows into the frame 39 from the opening formed between the pair of pillars 39c, or flows into the holder 47 through the communication holes 47d and 47e. Therefore, the entire temperature sensing portion 34 of the thermoelement 36 can sense the temperature of the cooling liquid.

[0066] When the temperature of the coolant sensed by the temperature sensing portion 34 is lower than a predetermined temperature, the wax in the temperature sensing portion 34 contracts, and the length of the portion of the piston 35 that protrudes from the valve shaft portion 33 is smallest. In this case, the first valve body 32 is pressed by the first biasing member 38 to seat on the first valve seat member 31, the first opening 31a is closed, and the coolant does not flow from the main passage 5 to the partial passage 5a leading to the radiator.

[0067] In this case, when the pressure of the cooling liquid is extremely small, the second valve body 42 of the differential pressure valve 40 is seated on the second valve seat member 41 by the second biasing member 43, but the second opening 41a has a gap 41c that is not closed by the second valve body 42. The cooling liquid in the main passage 5 flows into the bypass passage 3 through the auxiliary passage 49 defined by the gap 41c.

[0068] 5, when the pressure of the cooling liquid increases, the second valve body 42 is pressed down against the pressing force of the second biasing member 43, and the second opening 41a opens. The valve opening degree of the differential pressure valve 40 is controlled to a position where the pressure of the cooling liquid and the pressing force of the second biasing member 43 are in equilibrium. The flow rate of the cooling liquid flowing through the second opening 41a to the bypass passage 6 increases.

[0069] When the coolant reaches a predetermined temperature or higher, the wax in the temperature sensor 34 which senses the temperature expands, increasing the length of the portion of the piston 35 which protrudes from the valve shaft 33, but the tip of the piston 35 is held down by the piston receiver 37, so that the first valve body 32, the valve shaft 33 and the temperature sensor 34 descend together. As a result, the first valve body 32 descends against the pressing force of the first biasing member 38, and the first opening 31a opens. As a result, the coolant which has flowed into the frame 39 flows from the first opening 31a through the opening between the pair of arms 31d to the partial passage 5a of the main passage 5 which leads to the radiator. When the opening amount of the first valve body 32 becomes large, most of the cooling water flows into the partial passage 5a, and the cooling water pressure to the differential pressure valve 40 decreases, so that the second valve body 42 seats on the second valve seat member 41. Since the second opening 41a has a gap 41c that is not closed by the second valve body 42, some of the cooling liquid in the main passage 5 flows into the bypass passage 3 through the auxiliary passage 49 defined by the gap 41c.

[0070] According to the thermostat device 4, the flange 47b protruding outward from the holder 47 to which the second valve seat member 41 is fixed is caught by the engaging portion 39d provided on the frame 39. Furthermore, the holder biasing member which is the third biasing member 38 is sandwiched between the frame 39 and the holder 47 and compressed, biasing the flange 47b in a direction to maintain the flange 47b being caught by the engaging portion 39b. In this way, it is possible to obtain the thermostat device 4 in which the thermostat 30 and the differential pressure valve 40 are integrally connected, which easily tolerates dimensional tolerances of parts, is easy to assemble, and is easy to install in and replace in the main passage and the bypass passage.

[0071] In addition, by modifying an existing thermostat to a frame having the shape and structure of frame 39, and further adopting the differential pressure valve 40 and connecting unit 45, it is possible to easily modify the thermostat into a thermostat device with an integrated differential pressure valve.

[0072] The present invention is not limited to the above-described embodiments, but includes various modifications and equivalents that fall within the scope of the technical idea of ​​the present invention and its components.

[0073] 7, a thermostat device 7 according to another embodiment of the present invention is formed by integrally connecting a thermostat 50 having a housing 51 in which a first valve seat member, a piston receiver, and a frame are integrated, and the differential pressure valve 20 in which the holder 27 according to the first embodiment of the present invention is integrated, by a connecting unit 60. The connecting unit 60 includes the holder 27, a flange 27b protruding outward from the holder 27, a bottom frame 59a which can be fixed to the housing 51 and which constitutes an engagement portion on which the flange 27b is hooked when the holder 27 is inserted into the opening 59b, and a first biasing member 18 which constitutes a holder biasing member that biases the flange 27b of the holder 27 in a direction that keeps the flange 27b hooked on the engagement portion which is the bottom frame 59a. [Industrial Applicability]

[0074] The present invention can be utilized in a thermostat device that is mounted on an engine coolant circuit of an automobile and used. [Explanation of symbols]

[0075] 1,4,7 Thermostat device 2,2a,5,5a Main passage 3,6 Bypass Passage 10,30,50 Thermostat 11,31 First valve seat member 11a,31a 1st opening 12,32 First valve body 13,33 Valve stem 14,34 Temperature sensing part 15,35 piston 16,36 Thermoelement 18 First biasing member (holder biasing member) 19,39 Frames 19a,39d,59a Engagement part 20,40 Differential pressure valve 21,41 Second valve seat member 21a,41a 2nd opening 22,42 Second valve body 23, 43 Second biasing member 24,44 Support member 25 Push Nut 26,45,60 Connecting Unit 27,47 Holder 27a,47d,47e Communication hole 27b, 47b flange 38 First biasing member 46 third biasing member (holder biasing member)

Claims

1. A thermostat device to be mounted at a branch point between a main passage and a bypass passage, a thermostat for opening and closing the main passage; a differential pressure valve for opening and closing the bypass passage; a connection unit connecting the thermostat and the differential pressure valve, The thermostat comprises: a first valve seat member having a first opening formed therein for communicating with the main passage; a first valve body that opens and closes the first opening by being seated on and separated from the first valve seat member; a thermoelement having a valve stem to which the first valve body is fixed, a temperature sensor fixed to a base end of the valve stem and filled with a material that expands or contracts in response to temperature, and a piston protruding from a tip of the valve stem and moving forward or backward in response to the expansion or contraction of the material; a first biasing member that biases the first valve body in a closing direction; a frame fixed to the first valve seat member and supporting the first biasing member, The differential pressure valve comprises: a second valve seat member having a second opening formed therein for communicating with the bypass passage; a second valve body that is seated on and separated from the second valve seat member to open and close the second opening; a second biasing member that biases the second valve body in a closing direction; a support member fixed to the second valve seat member and supporting the second biasing member, The connecting unit comprises: a holder having a communication hole on a side surface and having the second valve seat member fixed to an inner periphery thereof; a flange protruding outwardly from the holder; an engagement portion provided on the frame and on which the flange is hooked; a holder biasing member that biases the holder in a direction that maintains the flange hooked to the engagement portion. A thermostat device comprising:

2. 2. The thermostat device according to claim 1, wherein the holder biasing member is a first biasing member that presses the flange protruding from the holder in a direction to maintain the flange hooked on the engagement portion.

3. 2. The thermostat device according to claim 1, wherein the holder biasing member is a third biasing member that is different from the first biasing member and the second biasing member and is sandwiched and compressed between the frame and the holder.

4. 2. The thermostat device according to claim 1, further comprising an auxiliary passage which always communicates from said main passage to said bypass passage when said device is installed.

5. 5. The thermostat device according to claim 4, wherein the auxiliary passage is a gap between an inlet of the bypass passage and the holder inserted into the inlet.

6. 5. The thermostat device according to claim 4, wherein the auxiliary passage is a gap of the second opening which is not closed by the second valve body when the second valve body is seated on the second valve seat member.

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