JP2009264592A - Thermostat device - Google Patents

Abstract

There is provided a thermostat device capable of reducing the number of components in each part, improving assemblability and workability, reducing costs, and further exhibiting performance as a thermostat.
A first valve body 22 that opens and closes a first fluid passage 3b and a second valve body 23 that opens and closes a second fluid passage 3d are provided. By operating together with the movement of the actuating body 21 due to the above, one of the first fluid passage 3b and the second fluid passage 3d is opened and the other is closed. The operating body 21 includes a case 31 that encloses a thermal expansion body having a property of expanding and contracting with a change in temperature at one end side and holding the piston 33 from the opening at the other end so as to be able to advance and retract. The outward flange portion 36 provided in the opening portion on the other end side of the case is referred to as a first valve body 22.
[Selection] Figure 2

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 to be circulated to the radiator side or an electrically controlled valve unit has been used so that the temperature of cooling water introduced into the engine can be controlled. Has been.

  That is, when a control valve such as a thermostat using the above thermal expansion body or a valve unit by electric control is installed in a part of the cooling water passage, for example, the inlet side or the outlet side of the engine, and the cooling water temperature is low When the control valve is closed and the cooling water is circulated through the bypass passage without passing through the radiator, and when the cooling water temperature is high, the control valve is opened and the cooling water is circulated through the radiator. The water temperature 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. 6, 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. 6, 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 and is composed of a fan and an electric motor that rotationally drives the fan.

  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. 7, the thermostat device 5 is provided with a first valve body 8 on one end side (here, the upper end side) of the operating body 7 that operates according to a temperature change of the fluid, and the other end side of the operating body 7. A second valve body 9 is provided (here, at the lower end side), 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. Moreover, the support body 12 protrudes from the outer side with the attaching part 12a with a 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 1a. 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.

  In the thermostat device 5 having such a configuration, a control plate that blocks the flow of the cooling water is provided around the second valve body 9 that opens and closes the bypass passage 3c, and the control plate is provided so as to pass through the bypass passage 3c. The cooled water is smoothly guided to the temperature sensing unit 7a in the operating body 7 and a fluid stirring action is generated in the vicinity of the operating body 7 so as to make the temperature distribution in the vicinity of the operating body 7 uniform. Thus, an attempt has been made to obtain accurate control and excellent responsiveness of the flow and flow rate of cooling water (see, for example, Patent Document 1).

Japanese Patent Publication No. 6-39190

  In the thermostat device 5 having the conventional structure described above, the bypass valve structure by the second valve element 9 for opening and closing the bypass passage 3c is complicated, the number of components is large, the assemblability is poor, the parts management is difficult, and the operation It had problems such as a problem in securing the above reliability.

  That is, in the thermostat device 5 having the conventional structure described above, when the first valve body 8 is attached to the guide portion 7b on one end side of the operating body 7 as a thermo element, the first valve body is provided on the outer periphery of the guide portion 7b. 8 is press-fitted, and it is necessary to provide a stopper ring (C-ring, E-ring, etc.) to prevent it from slipping out. It was a problem. Further, in such a structure, the precision of each part is required for press-fitting, and there is a problem in terms of workability.

  Further, in the above-described conventional structure, the valve rod 13 is provided at the lower end of the actuating body 7 as a thermo element, the second valve body 9 provided by the stopper 13a at the tip of the valve rod 13, and the second valve body 9 It is necessary to provide a coil spring 14 or the like for energizing, and the number of components is large, and it is troublesome to assemble.

Furthermore, since the bypass valve by the second valve body 9 described above has a structure that opens and closes the open end of the bypass passage 3c in the housing, the length of the valve stem 13 is changed depending on the size and shape of the housing. It is necessary to appropriately set the shape of the valve body 9 and the like, which is troublesome in parts management, resulting in high costs.
Further, in Patent Document 1 described above, it is necessary to provide a control plate in order to agitate the cooling water and ensure the accuracy in the temperature sensing unit 7a, and there is a problem that the number of parts further increases.

  The present invention has been made in view of such circumstances. For example, in a cooling system for an engine, the configuration of the entire thermostat device for controlling and circulating cooling water according to the cooling water temperature is reviewed, and the components of each part An object is to obtain a thermostat device that can reduce the number of points, improve the assemblability and workability, reduce the cost, and further exhibit the performance as a thermostat.

  In order to meet such an object, a thermostat device according to the present invention (the invention described in claim 1) includes a first valve body that opens and closes a first fluid flow path, and a first valve body that opens and closes a second fluid flow path. Two valve bodies, and by operating these valve bodies integrally in conjunction with the movement of the operating body due to the temperature change of the fluid, one of the first fluid flow path and the second fluid flow path is In the thermostat device configured to open and close the other, the working body encloses a thermal expansion body having a property of expanding and contracting with a temperature change at one end side, and opening from the opening at the other end side. A case that holds the piston so that the piston can move forward and backward, and the case is a bottomed cylindrical hollow container having substantially the same diameter, and the first valve body and the opening at the other end of the case A flange-shaped member that has an outward flange shape In addition, the bottomed portion side of the case is filled with a thermal expansion body, and a guide member having an inner end facing the thermal expansion body via a seal member is fitted from the case opening. A stepped portion having a small diameter on the bottomed portion side and a large diameter on the opening side is formed in a part of the case in the longitudinal direction, and the sealing member is positioned and locked at the stepped portion. Features.

  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 is a central portion of a flange-like member provided at the opening portion on the other end side of the case. A cylindrical holding portion projecting upward is formed, and the piston is slidably held.

  As described above, according to the thermostat device of the present invention, the first flange that opens and closes the first fluid flow path (main passage) is formed on the outward flange-like member provided at the opening end portion of the case constituting the operating body. Compared to the conventional structure, the overall structure of the device is simpler, the number of components is smaller, the assembly and workability are superior, and the cost can be greatly reduced. There is an excellent effect of being able to.

  Here, according to the present invention, unlike the conventional first valve body fixed to the outer periphery of the element case by press-fitting or the like, work such as press-fitting can be omitted, and processing accuracy for press-fitting is unnecessary. In addition, there is an advantage that the strength for press-fitting is not necessary, and the thickness of the material such as the case can be reduced.

  Furthermore, according to the present invention, the structure of the thermo element is simplified and the number of components thereof is small, and the first valve body is directly provided on the thermo element by welding or the like. In addition, it is possible to reduce the number of parts, improve the assemblability and workability, and reduce the cost.

  Further, according to the present invention, not only the structure of the thermo element itself is simplified and the number of components thereof is small, but also the first valve body is directly provided in the case of the thermo element integrally or by welding. In addition, the processing accuracy of each part can be ensured, and the number of parts can be reduced, the assemblability and workability can be improved, and the cost can be reduced.

  Furthermore, according to the present invention, since the fluid passing through the valve part always flows through the temperature sensing unit, the fluid is reliably mixed and the required temperature can be sensed. In addition, control according to the fluid temperature can be performed in a required state. Further, since the fluid flow can be controlled by the cylindrical portion, the control plate used in Patent Document 1 described above is unnecessary, and the number of parts can be reduced in this respect as well.

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. 1 is a state in which the thermostat device of FIG. 1 is incorporated in a cooling water circuit of an engine, and the first valve on the radiator side is in the open state and the second valve on the bypass passage side is in the closed state. FIG. FIG. 3 is a side sectional view when the first valve on the radiator side is closed from the state of FIG. 2 and the second valve on the bypass passage side is opened. It is the external view which looked at the thermostat apparatus of FIG. 3 from the side. It is principal part sectional drawing which shows the thermo element used for the thermostat apparatus which concerns on this invention. 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.

  1 to 5 show an embodiment of a thermostat device according to the present invention. In this embodiment, the thermostat device is attached to an engine inlet side in an engine cooling system and used for controlling the cooling water temperature. Will be explained.

  In these figures, the thermostat device, which is a temperature-sensing automatic valve indicated by reference numeral 20, includes a cooling water passage 3b on the radiator 2 side and an engine outlet portion 1c, as is apparent from FIG. 2 and FIG. 6 showing the conventional example described above. Cooling water passage that is attached to the intersection with the bypass passage 3c from the side and that selectively switches the flow of the cooling water in the first and second fluid flow paths constituted by these passages and reaches the engine inlet portion 1b. Used to feed 3d. Here, it is assumed that the first fluid flow path extends from the cooling water path 3b to the cooling water path 3d, and the second fluid flow path extends from the bypass path 3c to the cooling water path 3d. I do.

  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 And a frame 25 covering the periphery of the coil spring 24.

  Here, on the upper portion of the frame 25, a cap 26 is integrally connected to the frame 25, and a locking portion 26 a that locks an upper end portion of a piston of a thermo element 21, which will be described later, protrudes upward. . A packing 27 is provided on the outer peripheral flange portion of the cap 26 and, as shown in FIGS. 2 to 4, is locked and held in a part of the apparatus housing while maintaining liquid tightness. A valve seat 26b for the first valve body 22 is provided at the inner peripheral edge of the cap 26, thereby constituting a first valve that opens and closes the flow of cooling water in the first fluid flow path. Is done.

The thermo-element 21 is configured as shown in FIG. More specifically, the thermo element 21 includes a metal case 31 formed of a bottomed cylindrical hollow container having substantially the same diameter, and the bottom portion receives heat from the outside of the case 31 and is heated. Wax 32 is enclosed as a thermal expansion body that expands and contracts.
Here, in this embodiment, the step portion 31a is formed in a part of the case 31 in the longitudinal direction, the bottomed portion is formed with a small diameter, and the opening side is formed with a large diameter. This is a part for retaining when the thermostat device 20 is assembled as shown in FIGS. 1 and 2 and for positioning a seal member 35 to be described later. However, the case 31 can be made straight by managing the filling amount of the wax 32 to be constant.

  Inside the case 31, a piston 33 is disposed along the axial direction, an inner end thereof faces into the wax 32, and an outer end protrudes outward from an opening of the case 31. It is configured to move back and forth on the axis along with expansion and contraction. The retraction operation of the piston 33 into the case 31 is performed by an urging force such as a return spring (coil spring 24 in this embodiment) provided outside.

In the figure, reference numeral 34 denotes a guide member for slidably holding the piston 33, which is formed so as to have a substantially cylindrical shape, and is internally installed by fitting into the case 31 from one end side (opening side). Has been.
In the case 31, a seal member 35 for sealing the wax 32 in a bottomed portion in the case 31 is disposed at an inner end portion of the guide member 34. In the figure, 34a is a through hole for slidably holding the piston 33.

  A flange-like member 36 having a substantially outward flange shape that locks the outer end of the guide member 34 is integrally provided at a portion near the opening of the case 31. 31 is positioned and installed in a required state. A cylindrical holding portion 36a projecting upward is formed at the center of the flange-like member 36, and the holding portion 36a has a predetermined outer peripheral portion of the piston 33 protruding from the guide member 34. It is configured so as to be slidably held with an elastic force and to prevent cooling water from entering the case 31. Here, the flange-like member 36 is welded and fixed to an outward flange 31b provided at the opening of the case 31 by a welded portion 37 such as spot welding or laser welding.

  In FIG. 5, reference numeral 38 is a covering portion made of a heat-resistant synthetic resin or rubber member, and this covering portion 38 is folded back from the front surface portion including the holding portion 36 a of the flange-like member 36 to the back surface side. Is formed. The outer peripheral portion of the flange-shaped member 36 functions as the first valve body 22 that opens and closes the first fluid flow path, and is seated on the valve seat 26b of the cap 26 when the valve is closed.

  The thermo-element 21 having such a configuration eliminates the problems of the conventional sleeve-type and diaphragm-type thermo-elements, reduces the cost with the minimum number of necessary components, and further achieves thermal expansion. A change in volume accompanying the expansion and contraction of the body can provide an advancing / retreating operation with a required stroke of the piston, and a thermo element that is excellent in terms of responsiveness and durability can also be obtained. Further, the above-described thermo element 21 has an advantage that the shape and structure of the case 31, the guide member 34, and the like are further simplified, and the workability, assemblability, and cost reduction can be further effectively achieved.

In such a thermo element 21, according to the present invention, the temperature sensing portion which is the bottomed portion at the tip of the case 31 and in which the wax 32 is put is used as the second valve body 23. That is, as shown in FIGS. 1 and 2, the lower end of the frame 25 is integrally provided with a cylindrical portion 41 that slidably holds the lower end portion of the case 31 of the thermoelement 21. And the front end side of this cylindrical part 41 is connected to the said 2nd fluid flow path (bypass passage 3c side), and it is comprised so that the fluid of a 2nd fluid flow path may flow through this cylindrical part 41 inside. ing.
In addition, an opening 42 that is opened and closed by the second valve body 23 by the other end of the thermoelement 21 is provided as a window in a part of the tubular portion 41.

  Here, when such a cylindrical portion 41 is provided integrally with the frame 25, the number of parts constituting the second valve can be minimized and the number of parts as a whole can be reduced. Furthermore, the inside of the cylindrical part 41 is made into the 2nd fluid flow path by inserting the front-end | tip of this cylindrical part 41 in the channel | path hole of the housing which comprises a 2nd fluid flow path (bypass passage 3c side). Therefore, the effect of reducing the number of parts can be exhibited as compared with the conventional apparatus.

In the thermostat device 20 having the above-described configuration, when the cooling water temperature is low, as shown in FIGS. 1, 3, and 4, the piston 33 faces the wax 32 and has a relative protrusion amount with respect to the case 31. It is getting smaller. At this time, the thermo element 21 is urged upward in the figure by the urging force of the coil spring 24, whereby the first valve body 22 is in the valve closed position and the second valve body 23 is opened. In position.
At this time, the cooling water from the bypass passage 3 c flows to the engine inlet 1 b through the second fluid flow path and returns to the engine 1.

When the coolant temperature rises, the state is transmitted to the temperature sensing part of the thermo element 21 in the tubular part 41, and the wax 32 expands to push out the piston 33. At this time, since the piston 33 is locked by the cap 26, the case 31 and the like of the thermo-element 21 relatively move downward, the second valve body 23 at the lower end closes the opening 42, and the second 1 valve body 22 opens the valve.
If it becomes like this, the flow of the cooling water from the bypass passage 3c will decrease, and the cooling water cooled via the radiator 2 side will be sent to the engine 1 side.

  According to the above configuration, since the valve that opens and closes the second fluid flow path (bypass passage 3c side) is configured by the frame 25 and the thermo element 21 of the thermostat device 20, the number of components is small, and assembly is performed. In terms of performance, workability, and cost reduction.

  Further, the second valve for opening and closing the second fluid flow path (bypass passage 3c side) is constituted by a cylindrical portion 41 provided integrally with the apparatus frame 25, and the distal end side of the cylindrical portion 41 is formed. Since the cooling water (fluid) on the second fluid flow path side flows only through the inside of the tubular portion 41 by being inserted into the passage hole serving as the bypass passage 3c, the thermoelement 21 is laterally moved. The fluid pressure due to the fluid flow applied from the bottom is small, and uneven wear can be reduced.

  Furthermore, since the fluid passing through the valve part always flows through the temperature sensing part in the thermo element 21, the fluid is reliably mixed and the required temperature can be sensed, so there is no trouble such as temperature hunting, Control according to the fluid temperature can be performed in the required state. Further, since the fluid flow can be controlled by the cylindrical portion 41, a control plate for controlling the fluid flow as in the above-described conventional apparatus is unnecessary, and the number of parts can also be reduced in this respect.

  Further, not only the structure of the thermo element 21 is simplified and the number of components thereof is small, but also a flange-like member 36 serving as a first valve body is directly and integrally provided on the thermo element 21 by welding or the like. The processing accuracy of each part can be secured, and the number of parts can be reduced, the assemblability and workability can be improved, and the cost can be reduced.

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 and structure of each part can be appropriately modified and changed.
For example, in the above-described embodiment, the example in which the thermostat device 10 is incorporated in the inlet portion 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 portion 1c side of the engine 1 is provided. Needless to say, the same effects can be obtained even when incorporated in the above. At this time, the flow of the fluid (cooling water) is reversed.

  Further, in the above-described embodiment, the wax 32, the seal member 35, and the guide member 34 are incorporated in the case 31 having substantially the same diameter, and the flange-like member 36 serving as a locking member for locking these at the case opening is welded. However, the present invention is not limited to this, and it goes without saying that the present invention is not limited to this and can be applied to any operating element such as a thermo element having an equivalent structure. . For example, the flange-shaped member 36 serving as the first valve body 22 may be integrally formed on the case 31 side. In this case, a locking member for locking the member incorporated in the case 31 may be provided separately.

DESCRIPTION OF SYMBOLS 1 Engine 1b Engine inlet part 1c Engine outlet part 2 Radiator 3 Cooling water circuit 3a, 3b Cooling water path 3c Bypass path 3d Cooling water path 20 Thermostat device 21 Thermo element 22 1st valve body 23 which comprises 1st valve 2nd Second valve body 24 constituting the valve Coil spring (biasing means)
25 Frame 26 Cap 26a Locking portion 26b Valve seat 31 Case 31a Outward flange 32 Wax 33 Piston 34 Guide member 35 Seal member 36 Flange-shaped member (locking member)
37 welded part 38 covering part 41 cylindrical part 42 opening part

Claims (2)

A first valve body that opens and closes the first fluid flow path; and a second valve body that opens and closes the second fluid flow path. In the thermostat device configured to open one side of the first fluid channel and the second fluid channel and close the other by operating together in an integrated manner,
The operating body includes a case that encloses a thermal expansion body having a property of expanding and contracting with a temperature change at one end side, and holding the piston so as to be movable forward and backward from the opening at the other end side.
The case is a bottomed cylindrical hollow container having substantially the same diameter,
In the other end side opening portion of the case, a flange-like member that has an outward flange shape that serves as the first valve body is integrally provided,
Inside this case, the bottomed side is filled with a thermal expansion body,
A guide member whose inner end faces the thermal expansion body via a seal member is configured to be fitted from the case opening,
A thermostat characterized in that a step portion having a small diameter on the bottomed portion side and a large diameter on the opening side is formed in a part of the longitudinal direction of the case, and the sealing member is positioned and locked at the step portion. apparatus. The thermostat device according to claim 1,
Forming a cylindrical holding portion projecting upward at the center of the flange-shaped member provided in the other end opening portion of the case;
A thermostat device characterized in that the piston is slidably held.

Images