JP2005127361A - Thermostat device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermostat device capable of reexamining a structure of the entire device and of obtaining needed flow rate characteristics as a thermostat by reducing water flow resistance inside the device. <P>SOLUTION: In the thermostat device 20 equipped with a thermoelement 21 for sliding a piston rod 21a by thermal expansion and contraction of a thermal expansion body, a lip-shaped cylindrical part 30 having a minimum opening diameter part and an inner face bent and formed such that both end sides of the piston rod 21a in the sliding direction have large diameter is provided for a flange-shaped member 27 having, on an opening part inner peripheral edge, a valve seat 29 on which a valve element 22 is arranged so as to be capable of being seated. In addition, a cylindrical part 33 for streamlining, which is bent and formed such that a piston rod tip side of the thermoelement 21 has the minimum diameter and the valve element 22 side has large diameter and which has an outer peripheral face connecting with a face in the valve seat 29 side of the valve element 22, is provided for an outer peripheral part of the thermoelement 21 incorporating the thermal expansion body and having the valve element 22. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling water circuit for an engine that circulates cooling water for cooling an internal combustion engine (hereinafter referred to as an engine) used for an automobile or the like with a heat exchanger (hereinafter referred to as a radiator). The present invention relates to a thermostat device that is a temperature-sensitive automatic valve that is used to control the coolant temperature by switching the flow of engine coolant by operating according to the temperature change.

  In order to cool an automobile engine, a water-cooled cooling system using a radiator is generally used. Conventionally, in this type of cooling system, a thermostat using a thermal expansion body that adjusts the amount of cooling water circulated to the radiator side and a valve unit by electric control are used so that the temperature of the cooling water introduced into the engine can be controlled. ing.

  That is, when a control valve such as a thermostat using the thermal expansion body or a valve unit by electrical control is installed in a part of the cooling water passage, for example, at the inlet side or outlet side of the engine, and the cooling water temperature is low The control valve is closed and the cooling water is circulated through the bypass passage without passing through the radiator. When the cooling water temperature becomes high, the control valve is opened and the cooling water is circulated through the radiator to The temperature of the cooling water can be controlled to a required state.

An overall outline of a cooling system (cooling water temperature control system) for an automobile engine using a thermostat will be described below with reference to FIG.
In FIG. 5, reference numeral 1 denotes an automobile engine as an internal combustion engine constituted by a cylinder block and a cylinder head. A cooling water passage indicated by an arrow a is formed in the cylinder block and cylinder head of the engine 1. Yes.
Reference numeral 2 denotes a heat exchanger, that is, a radiator. As is well known, a cooling water passage is formed in the radiator 2, and the cooling water inlet 2 a and the cooling water outlet 2 b of the radiator 2 are connected to the engine 1. And connected by a cooling water circuit 3 for circulating the cooling water.

The cooling water circuit 3 includes an outflow side cooling water passage 3 a that communicates from a cooling water outlet 1 c provided in the engine 1 to a cooling water inlet 2 a provided in the radiator 2, and cooling water provided in the radiator 2. The inflow side cooling water passage 3b that communicates from the outlet portion 2b to the cooling water inlet portion 1b provided in the engine 1 and a bypass passage 3c that connects the intermediate portions of the cooling water passages 3a and 3b.
A cooling water circulation path is formed by the engine 1, the radiator 2, and the cooling water path 3.

  A thermostat device 5 for controlling the flow and flow rate of the cooling water in the cooling water circuit 3 according to the temperature of the cooling water is in the middle of the cooling water passage 3b on the inlet side of the engine 1, It is provided at the intersection where the cooling water from the radiator 2 and the bypass passage 3c can be switched. In addition, 3d in the figure is a cooling water channel from the intersection to the inlet 1b of the engine 1.

  Although not shown in FIG. 5, the rotating shaft is rotated by the rotation of the crankshaft (not shown) of the engine 1 at the inlet 1 b portion of the engine 1 to forcibly circulate the cooling water in the cooling water passage 3. A water pump is arranged. Further, reference numeral 6 in the figure denotes a cooling fan unit for forcibly taking cooling air into the radiator 2.

  The flow of the cooling water in the cooling water circuit 3 is switched and controlled by the thermostat device 5. That is, when the cooling water temperature is low, the cooling water is circulated through the bypass passage 3c. When the cooling water temperature is high, the cooling water is circulated not to the bypass passage 3c but to the radiator 2 side to supply the cooling water to the engine 1. Is configured to supply.

  As shown in FIG. 6, the thermostat device 5 is provided with a first valve body 8 on one end side (upper side in the figure) of an operating body 7 that operates according to a change in temperature of the fluid, and the other end side of the operating body 7 ( A second valve body 9 is provided on the lower side in the drawing, and a coil spring 10 as a biasing means for biasing the first valve body 8 to the valve closed position and a main body frame 11 are provided.

  The operating body 7 is a so-called thermo element, and includes a temperature sensing portion 7a and a guide portion 7b. A thermal expansion body 7c such as wax that expands and contracts by sensing the temperature of the fluid is built in the temperature sensing portion 7a. A piston rod 7d is fitted into a guide portion 7b extending from the tip of the temperature sensing portion 7a. In addition, a support body 12 that presses the tip of the piston rod 7d is provided at the tip of the piston rod 7d.

The first valve body 8 is provided in the guide portion 7 b, and the pressing body 12 serves as a valve seat for the first valve body 8. In addition, the presser 12 has a flange-like portion 12a protruding from the outside, which serves as an attachment portion with the water channel. 12b is a packing.
The second valve body 9 is attached to a valve rod 13 extending from the rear end of the temperature sensing portion 7a with a stopper 13a, and is interposed between the second valve body 9 and the temperature sensing portion 7a. The second valve element 9 is biased toward the end of the valve rod 13 by the coil spring 14.
The coil spring 10 as the urging means is provided to be retracted between the first valve body 8 and the frame 11, and always urges the first valve body 8 to the valve closed position.

  Such a thermostat device 5 is positioned so that the first valve body 8 opens and closes the cooling water passage 3b and the second valve body 9 opens and closes the bypass passage 3c, and operates as follows. That is, the thermal expansion body 7c in the temperature sensing unit 7a expands due to an increase in the cooling water temperature and presses the piston rod 7d, and the operating body 5 operates against the urging force of the coil spring 10. As a result, the first valve body 8 moves to the open position to open the cooling water passage 3b, and the second valve body 9 moves to the valve close position to close the bypass passage 3c. Further, the thermal expansion body 7c contracts due to the cooling water temperature falling, and the pressing force of the piston rod 7d is weakened. The biasing force of the coil spring 10 moves the first valve body 2 to the valve closed position, and the water passage 3b is moved. In addition to closing, the second valve body 9 is moved to the valve open position to open the bypass passage 3c.

  Thus, the thermostat device 5 mixes and switches the warmed cooling water from the engine water jacket 1 and the cooled cooling water from the radiator 2 in the engine cooling water circuit 3 as a temperature sensing type automatic valve. Thus, the coolant temperature sent to the engine water jacket 1 is controlled to an appropriate temperature (see, for example, Patent Document 1).

Japanese Patent No. 3225386

Incidentally, the conventional thermostat device 5 described above has the following problems.
That is, in order to satisfy the requirements of the structure and cost of the conventional thermostat device, the flow characteristic that should be emphasized as a function of the thermostat is the opening diameter of the valve body that determines the flow rate when the thermostat is fully open. The housing shape and thermostat structure have never been devised.

For this reason, in engines that rotate to high speeds, engines that have a large resistance at the water pump inlet, and those that require the maximum flow rate, the required flow rate may not be secured due to insufficient flow when fully opened or due to the occurrence of cavitation. A bug was invited.
The reason for this is that the element that is the main component of the thermostat device is located in the fluid flow path, or the shape of the flange that constitutes the valve seat is formed with priority given to production efficiency by pressing, It was because it did not consider.

  The present invention has been made in view of such circumstances, for example, in a thermostat device for controlling and circulating cooling water according to the cooling water temperature in an engine cooling system, the overall configuration has been reviewed, An object of the present invention is to obtain a thermostat device capable of reducing the water flow resistance and obtaining the required flow characteristics as a thermostat.

  In order to meet such an object, a thermostat device according to the present invention (the invention according to claim 1) is provided in a cooling water passage of an internal combustion engine, and incorporates a thermal expansion body that thermally expands or contracts due to a temperature change of the coolant. In the thermostat device having a piston rod that slides due to thermal expansion and contraction of the thermal expansion body, and opening and closing the valve body by sliding of the piston rod accompanying the volume change of the thermal expansion body, the valve body The flange-like member having a valve seat arranged to be seated on the inner peripheral edge of the opening has an inner surface that has a minimum opening diameter portion and is curved so that both ends in the sliding direction of the piston rod have a large diameter. A lip-shaped tube portion is provided.

  The thermostat device according to the present invention (the invention according to claim 2) is a specific limitation of the thermostat device according to claim 1, and the lip-shaped tube portion is circumferential in the inner periphery of the opening of the flange-shaped member. It is formed in the part except one part.

  A thermostat device according to the present invention (invention of claim 3) is provided in a cooling water passage of an internal combustion engine, and incorporates a thermal expansion body that thermally expands or contracts due to a temperature change of the coolant, and the thermal expansion of this thermal expansion body In a thermostat device having a piston rod that slides by contraction and opens and closes the valve body by sliding of the piston rod accompanying a change in volume of the thermal expansion body, the thermal expansion body is incorporated and the valve body is The thermoelement provided in the outer peripheral portion has an outer peripheral surface that is curved so that the tip end side of the piston rod of the thermoelement has a minimum diameter and the valve body side has a large diameter and is continuous with the valve seat side surface of the valve body. The rectification | straightening cylindrical part which has is provided.

  The thermostat device according to the present invention (the invention according to claim 4) is a specific limitation of the thermostat device according to claim 3, and is the valve seat side of the valve body and the cylindrical portion for rectification. A surface continuous to the outer peripheral portion of the first and second outer peripheral portions is configured by a plane portion orthogonal to the fluid flow, and a tapered portion along the fluid flow at the outer peripheral edge portion, and the plane portion has at least an opening diameter of the valve seat. It is characterized by having a size that occupies more than half the area.

  The thermostat device according to the present invention (the invention according to claim 5) is a specific limitation of the thermostat device according to claim 3 or claim 4, and the rectifying tubular portion is the valve body or It is formed integrally with at least one of the members constituting the thermo element.

  The thermostat device according to the present invention (the invention according to claim 6) is a specific limitation of the thermostat device according to any one of claims 3 to 5, so that the valve body can be seated. A flange-like member having a valve seat arranged on the inner peripheral edge of the opening has a lip shape having an inner surface that has a minimum opening diameter portion and is curved so that both ends in the sliding direction of the piston rod have a large diameter. A cylindrical portion is provided.

  According to the present invention, a fluid flow function by a rectifying tubular portion provided on a lip-shaped tubular portion formed at an opening end portion serving as a valve seat or an outer peripheral portion adjacent to a valve seat side of a valve body in a thermo element. Thus, it is possible to ensure the required flow characteristics as a thermostat device.

  In particular, according to the present invention, the opening edge portion of the opening of the flange-shaped member formed separately from the cap having the locking portion for locking the tip of the piston rod of the thermo element is made to flow through the fluid flow. A fluid guide shape capable of smoothly flowing a fluid can be obtained by the lip-shaped cylindrical portion curved in the direction of reducing the resistance, that is, the constriction direction or the spreading direction.

  In addition, according to the present invention, a required flow rate characteristic can be obtained by simply or integrally providing a straightening cylindrical portion having an outer peripheral surface that curves from the outer peripheral portion of the thermo element to the valve seat side surface of the valve element. The rectifying function that can be obtained can be obtained. In particular, by adjusting the shape of the cylindrical portion for rectification, the opening area of the valve can be sufficiently secured and the water flow resistance can be reduced, so that a smooth fluid flow can be secured, and the flow characteristics Will be improved.

  As described above, according to the thermostat device of the present invention, the lip-shaped cylindrical portion formed at the opening end portion serving as the valve seat of the flange-shaped member or the outer peripheral portion of the thermoelement on the valve seat side of the valve body. The required flow characteristics as a thermostat device can be ensured by the fluid flow function by the straightening cylindrical portion provided in the thermostat device.

  In particular, according to the present invention, the opening edge portion of the opening of the flange-shaped member formed separately from the cap having the locking portion for locking the tip of the piston rod of the thermo element is made to flow through the fluid flow. The fluid guiding shape is obtained by bending (curling or tapering) that curves in the direction of reducing resistance, that is, in the constriction direction or in the spreading direction. However, there are advantages such as no problem and cost advantages.

  Further, according to the present invention, since the rectifying cylindrical portion having a curved surface extending to the outer peripheral portion of the thermo element on the fluid inflow side of the valve body is provided integrally or integrally, the structure is There is an advantage that it is simple, excellent in processing and assembling, and can easily obtain the required flow characteristics. In particular, the shape of the cylindrical portion for rectification, the flat portion and the tapered portion are combined and adjusted in a required relationship, so that a sufficient valve opening area can be secured and the water flow resistance can be reduced. A fluid flow can be ensured and the flow rate characteristics can be improved.

  1 to 4 show one embodiment of a thermostat device according to the present invention. Here, in this embodiment, a case will be described in which the cooling system for an engine is arranged to face the cooling water channel on the inlet side of the engine and used for controlling the cooling water temperature.

  In these figures, a thermostat device, which is a temperature sensing type automatic valve indicated by reference numeral 20, is clear from the cooling water passage 3b on the radiator 2 side and the engine outlet portion 1c side as apparent from FIG. Attached to the intersection with the bypass passage 3c, the flow of the cooling water in the first and second fluid flow paths constituted by these passages is selectively switched to supply the cooling water passage 3d reaching the engine inlet 1b. Used to send.

  As shown in FIGS. 1 and 2, the thermostat device 20 includes a thermo element 21 as an operating body that operates according to a change in the temperature of cooling water, and a first and second unit that is integrally or integrally provided with the thermo element 21. First and second valve bodies 22 and 23 for opening and closing the fluid flow path, and biasing means for attaching the first valve body 22 to the valve closed position and the second valve body 23 to the valve open position A coil spring 24 and a cup-shaped frame 25 covering the periphery of the coil spring 24.

  The thermo-element 21 described above encloses a thermal expansion body such as wax in its interior, and by sensing the temperature of the fluid, the piston is driven by the thermal expansion and contraction of the thermal expansion body, whereby the piston rod 21a. Is pushed out or retracted in the axial direction, the details of which are well known and will not be described here.

  Further, on the upper part of the frame 25, a cap 26 provided on the upper end side for locking an upper end portion of a piston rod 21a projecting from a thermo element 21, which will be described later, and the first valve A flange-like member 27 that forms a valve seat 29 corresponding to the body 22 on the inner peripheral edge of the opening is integrally connected to the upper end side of the frame 25.

  Here, as shown in FIGS. 1 to 3, the cap 26 is formed with a locking portion 26 a on the upper end side by bending the strip-like plate material in a triangular shape in a side view, and both end portions on the lower end side are the flanges. It is assembled on the member 27 and fixed by welding, brazing, soldering, caulking or the like. 2 and 3, the upper end 25a of the frame 25 is fixed by welding, brazing, soldering, caulking or the like with the lower end of the cap 26 assembled on the flange-like member 27. Is done. In this embodiment, the upper end portion 25a of the frame 25 is caulked to the flange-like member 27 and both end portions on the lower end side of the cap 26 assembled to the upper surface thereof, so that these members are integrated. . In the figure, reference numeral 25a denotes a connecting portion by caulking.

  A first valve that opens and closes the flow of cooling water in the first fluid flow path is constituted by the valve seat 29 provided at the inner peripheral edge portion of the opening in the flange-shaped member 27 and the first valve body 22. Has been. Although not shown, the second valve body 23 faces the opening end of the bypass passage 3c that opens to a part of the valve housing, and the opening end serves as a valve seat to move the thermo element 21 through the flow path. It can be opened and closed. Reference numeral 23 a denotes a spring that elastically supports the second valve body 23.

  According to the present invention, the valve on which the first valve element 22 on the thermo element 21 side sits on the inner peripheral edge of the opening in the flange-like member 27 fixed to the housing member (not shown) whose outer peripheral edge is the fixed side. In the thermostat device 20 as the seat 29, an inner surface that has a minimum opening diameter portion at the inner peripheral edge of the opening of the flange-shaped member 27 and is curved so that both ends in the sliding direction of the piston rod 21a have a large diameter. It is characterized in that a lip-shaped cylindrical portion 30 having a lip is provided so as to reduce the water flow resistance when the valve is open.

  Here, as such a lip-shaped cylindrical portion 30, it is desirable to provide the entire periphery of the inner peripheral edge of the opening of the flange-shaped member 27. However, since it is necessary to provide both end portions on the lower end side of the cap 26, this embodiment is implemented. In the embodiment, a part in the circumferential direction corresponding to the lower end portion of the cap 26 is cut out. Therefore, the cap 26 has a shape that does not interfere with the lip-shaped cylindrical portion 30 and is integrally coupled without interference. In this way, the flange-like member 27 and the cap 26 are configured separately, and the lip-shaped cylindrical portion 30 is provided, thereby increasing the opening area on the fluid inflow side of the first valve in the thermostat device 20. It can be made.

The orientation of the lip-shaped tube portion 30 is ideally downward (fluid outflow side) in the figure, but may be upward (fluid inflow side). Experiments have confirmed that this orientation does not affect the flow control of the fluid.
Furthermore, the form provided in the perimeter of the opening part of the flange-shaped member 27 may be sufficient by changing the shape of the both ends of the lower end side of the cap 26 into the shape which does not interfere with the lip-shaped cylinder part 30.

  Further, according to the present invention, in the configuration described above, the tip of the piston rod 21a of the thermo element 21 is disposed on the outer peripheral portion of the thermo element 21 that is close to the fluid inflow side (valve seat 29 side) of the first valve body 22a. A straightening cylindrical portion 33 is provided which is curved so that the side is the minimum diameter and the valve body side is a large diameter and has an outer peripheral surface continuous to the fluid inflow side (valve seat 29 side) surface of the valve body 22a. The fluid is guided toward the outer peripheral edge of the valve body 22a when the valve is opened.

  Here, in this embodiment, as shown in FIG. 1 and the like, a cylindrical member as the straightening cylindrical portion 33 is provided by interposing it on the outer peripheral portion of the thermoelement 21, and the outer side surface thereof is provided. Is continuously formed on the outer surface of the packing 22a provided on the outer peripheral edge of the valve body 22 so as to perform a rectifying function.

Such a straightening cylindrical portion 33 may be formed integrally or integrally with the above-described packing 22a. Moreover, you may comprise the cylindrical part 33 for rectification | straightening by forming the shape of the plate part which comprises the said valve body 22 so that said curved surface may be obtained. In other words, the bending direction of the attachment portion of the plate portion to the thermo element 21 may be reversed. Furthermore, by forming integrally or integrally with the member on the thermo element 21 side, the above rectifying cylindrical portion 33 may be formed, or it may be constituted by a member different from the member on the thermo element 21 side. The modification of this can be considered.
In short, it is only necessary that the flow of the fluid from the fluid inflow side to the fluid outflow side of the valve body 22 can be smoothly performed in a state in which the water flow resistance is reduced by providing the straightening cylindrical portion 33.

  Here, when the curvature R of the rectifying surface from the outer peripheral surface of the thermoelement 21 to the flat portion of the valve body 22 in the rectifying tubular portion 33 is reduced, the temperature-lift characteristic of the thermoelement 21 and the thermostat device. The flow rate in a state where 20 is not fully opened but is an intermediate opening (hereinafter referred to as an intermediate lift) increases, and the flow rate at the fully open lift decreases. On the other hand, when the curvature R is increased, the flow rate during the intermediate lift is reduced, and the flow rate during the fully open lift is increased. In consideration of these balances, it is necessary to set the curvature R described above.

  Therefore, in the same thermostat device 20, the temperature-flow rate characteristic is changed by changing the curvature R of the rectifying surface from the outer peripheral surface of the thermoelement 21 to the flat portion of the valve body 22 in the rectifying tubular portion 33. It becomes possible to do. For this reason, for example, when it is desired to increase the flow rate from the beginning of opening of the valve in the thermostat device 20 to an intermediate level, the curvature R is decreased, and the characteristics when the valve is fully opened such as when the temperature rises or the engine load increases are emphasized. In this case, the curvature R should be increased.

  Further, a plane portion that is on the fluid inflow side (valve seat 29 side) of the valve body 22 and that continues from the outer peripheral portion of the rectifying tubular portion 33 to the outer peripheral edge of the valve body 22 is orthogonal to the fluid flow. 33a and the taper part 33b along the flow of the fluid in the outer periphery part.

  The flat surface portion 33a on the fluid inflow side of the valve body 22 including the straightening cylindrical portion 33 sufficiently secures an opening area between the flat surface portion 33a and the valve seat 29 when the valve is opened. To function. The tapered portion 33b serves to smooth the flow of fluid flowing out between the valve element 33 and the valve seat 29. The tapered portion 33b described above is seated in close contact with the curved inner peripheral surface of the lip-shaped cylindrical portion 30 formed on the inner peripheral edge of the opening of the flange-shaped member 27 when the valve is closed. Seal.

  Here, the flat surface portion 33a is formed to have a size that occupies an area of 70% of the valve opening diameter by the valve seat 29 or an area of 70% or more. That is, if the flat surface portion 33a is small and the curvature R is large, the fluid flow is smooth, but the valve diameter is smaller than the minimum opening diameter of the rectifying tubular portion 33 that is the actual opening diameter. When the valve is opened, the distance between the valve seat 29 and the flow path is narrowed. On the contrary, when the flat surface portion 33a is close to 100% with respect to the opening diameter and the curvature R is small, the space between the valve seat 29 is increased when the valve is opened, and the flow path is expanded. This is because the flow on the fluid inflow side of the valve body 22 approaches a right angle and it is difficult to obtain a smooth flow. In order to solve these problems, it is preferable to form with the above-described area of 70% or more.

  According to the above configuration, the fluid flow by the lip-shaped cylindrical portion 30 formed on the inner peripheral edge portion of the opening serving as the valve seat 29 in the flange-shaped member 27 or the rectifying cylindrical portion 33 provided on the fluid inflow side of the valve body 22. The required flow characteristic as the thermostat device 20 can be ensured by the water flow function. FIG. 4 shows the flow characteristics with respect to the thermostat lift amount by the thermostat device 20 having such a configuration, and it has been confirmed by experiments that it is improved by about 20% as compared with the conventional mass-produced product indicated by a thin solid line in the figure. .

Note that the present invention is not limited to the structure described in the above-described embodiment, and it goes without saying that the shape, structure, and the like of each part constituting the thermostat device 20 can be appropriately modified and changed.
For example, in the above-described embodiment, the case where the lip-shaped cylindrical portion 30 is formed on the inner peripheral edge of the opening of the flange-shaped member 27 and the rectifying cylindrical portion 33 is provided on the fluid inflow side of the valve body 22 has been described. However, the present invention is not limited to this, and even if at least one of the lip-shaped cylindrical portion 30 and the rectifying cylindrical portion 33 is provided, the required effect can be exhibited.

  Further, in the above-described embodiment, the example in which the thermostat device 20 is incorporated on the inlet 1b side of the engine 1 in the engine coolant circuit has been described. However, the present invention is not limited to this, and the outlet 1c of the engine 1 is provided. Needless to say, even when incorporated on the side, the same effect can be obtained. At this time, the flow of the fluid (cooling water) is reversed.

BRIEF DESCRIPTION OF THE DRAWINGS It is principal part sectional drawing for demonstrating one Embodiment of the thermostat apparatus which concerns on this invention, and demonstrating schematic structure of the whole thermostat apparatus. It is a top view of the thermostat apparatus of FIG. It is a front view of the thermostat apparatus of FIG. 1, FIG. It is a graph which shows a lift-flow rate characteristic. It is explanatory drawing which shows the engine cooling water circuit which integrated the thermostat apparatus in the inlet side of the engine. It is principal part sectional drawing for demonstrating an example of the conventional thermostat apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 1b ... Engine inlet part, 1c ... Engine outlet part, 2 ... Radiator, 3 ... Cooling water circuit, 3a, 3b ... Cooling water channel, 3c ... Bypass channel, 3d ... Cooling water channel, 20 ... Thermostat device, 21 ... Thermo element, 21a ... piston rod, 22 ... first valve element, 23 ... second valve element, 24 ... coil spring (biasing means), 25 ... frame, 26 ... cap, 26a ... locking part, 27 ... Flange-shaped member, 29 ... first valve seat, 30 ... lip-shaped cylinder part, 33 ... cylindrical part for rectification, 33a ... plane part, 33b ... taper part.

Claims (6)

A thermal expansion body, which is provided in a cooling water passage of an internal combustion engine and thermally expands or contracts according to a temperature change of the cooling water, has a piston rod that slides due to thermal expansion and contraction of the thermal expansion body, and the thermal expansion body In the thermostat device that opens and closes the valve body by sliding the piston rod accompanying the volume change of
A flange-like member provided with a valve seat on the inner periphery of the opening, on which the valve body can be seated, has a minimum opening diameter portion and is curved so that both ends in the sliding direction of the piston rod have a large diameter. A thermostat device characterized in that a lip-shaped cylindrical portion having an inner surface is provided. The thermostat device according to claim 1,
The said lip-shaped cylinder part is formed in the part except the one part of the circumferential direction in the inner peripheral edge of the opening part of a flange-shaped member, The thermostat apparatus characterized by the above-mentioned. A thermal expansion body, which is provided in a cooling water passage of an internal combustion engine and thermally expands or contracts according to a temperature change of the cooling water, has a piston rod that slides due to thermal expansion and contraction of the thermal expansion body, and the thermal expansion body In the thermostat device that opens and closes the valve body by sliding the piston rod accompanying the volume change of
The thermo element including the thermal expansion body and having the valve body at the outer peripheral portion is curved so that the tip end side of the piston rod of the thermo element has a minimum diameter and the valve body side has a large diameter. A thermostat device having a straightening cylindrical portion having an outer peripheral surface continuous with a valve seat side surface. The thermostat device according to claim 3,
A surface on the valve seat side of the valve body and continuing to the outer peripheral portion of the straightening cylindrical portion is a plane portion orthogonal to the fluid flow, and a tapered portion along the fluid flow at the outer peripheral edge portion thereof. Composed by
The thermostat device is characterized in that the flat portion has a size that occupies an area of at least half of the opening diameter of the valve seat. The thermostat device according to claim 3 or 4,
The thermostat device is characterized in that the straightening cylindrical portion is integrally formed with at least one of the members constituting the valve body or the thermo element. The thermostat device according to any one of claims 3 to 5,
A flange-like member provided with a valve seat on the inner periphery of the opening, on which the valve body can be seated, has a minimum opening diameter portion and is curved so that both ends in the sliding direction of the piston rod have a large diameter. A thermostat device characterized in that a lip-shaped cylindrical portion having an inner surface is provided.

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