CA1324596C - Wax-pellet thermostat - Google Patents
Wax-pellet thermostatInfo
- Publication number
- CA1324596C CA1324596C CA000615782A CA615782A CA1324596C CA 1324596 C CA1324596 C CA 1324596C CA 000615782 A CA000615782 A CA 000615782A CA 615782 A CA615782 A CA 615782A CA 1324596 C CA1324596 C CA 1324596C
- Authority
- CA
- Canada
- Prior art keywords
- piston
- guide member
- valve
- thermostat
- secured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
ABSTRACT
A wax-pellet thermostat having a valve seat, a piston secured to the valve, a guide member slidably mounted on the piston, a valve secured to the guide member, a seal spool secured to the guide member, and a wax provided in the cylinder. A seal device is provided in the guide member at a top portion thereof around the piston. The seal device comprises an annular separator slidably mounted on the piston, and at least one O-ring provided adjacent the annular separator.
A wax-pellet thermostat having a valve seat, a piston secured to the valve, a guide member slidably mounted on the piston, a valve secured to the guide member, a seal spool secured to the guide member, and a wax provided in the cylinder. A seal device is provided in the guide member at a top portion thereof around the piston. The seal device comprises an annular separator slidably mounted on the piston, and at least one O-ring provided adjacent the annular separator.
Description
-` 1 324596 This application is a divisional of my copending application Serial No. 539331 filed on June 10, 1987.
The present invention relates to a wax-pellet thermostat for automotive engines.
The conventional wax-pellet thermostat comprises a thermo-sensitive device and a valve device~
The thermo-sensitive device includes a steel piston, a guide member slidably engaged with the piston, a rubber ~j seal spool around the piston, and a wax. The piston is sealed by a sealing device provided in the guide member.
~! However, if the sealing device deteriorates, a space in the seal spool is communicated with a coolant passage.
Under such a condition, when the temperature of coolant rapidly decreases ~rom high temperature (about 100C) to lo~ temperature (bslow 40C), the space in the seal spool becomes a vacuum. Accordingly, the coolant is inducted into the space. Since the seal spool tightly grips the piston, the coolant in the space cannot be discharged. As described hereinafter, the valve is ';~ slightly raised by the coolant in the space, which ~'~ causes the opening temperature of the valve to decrease.
As a result, the engine is overcooled, thereby reducing ,. .
^~ 25 the thermal efficiency of the engine and increasing the amount of emissions. The amount of the coolant in the ~J space increases with time, so that the valvs lift increases, which causes engine trouble.
;~:
i~ An object of the invention is to provide a thermostat which may prevent the induction of coolant.
..:~:
According to the present invention, there is provided a thermostat having a housing having a valve seat, a piston sacured to the housin~, a guide member . .
,, .
1 32~596 slidably mounted on the piston, a valve secured to the guide member, a seal spool secured to the guide member around a lower portion of the piston, a heat conductive cylinder secured to the guide member and surrounding the seal spool, and a wax provided in the cylinder.
The thermostat has a seal device provided in the guide member at a top portion thereof around the i piston so as to prevent the enter of coolant.
: ;
These and other objects and features of the present invention will become more apparent from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1 and 2 are sectional views of a thermostat of the present invention;
Figs. 3 and 4 are sectional views of a conventional thermostat;
Fig. 5 is a graph showing valve lifts of the ~ thermo~tat of the present invention and conventional one j ~ 20 with respect to temperature; and Fig. 6 shows the operation of the thermostat of ',; the present invention.
i DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
;1 Referring to Figs. 1 and 2, the thermostat of the present invention comprises a housing 2 forming a '! valve seat 1, a frame 3 secured to the housing 2~ A
thermo-sensitive device 5 comprises a steel piston 8 secured to the housing 2 at a top 12, guide member 6 slidably engaged with the piston 8, primary valve 4 secured to the guide member 6, heat conductive cylinder 11 secured to the guide member 6, rubber seal spool 9 secured to the guide member 6, wax pellet 10 provided in ~, .
:, . . , . : .: . : ::: .
:` ` 1 324596 :
the cylinder 11, and seal packing 15 for preventing count~r flow of coolant. A return coil spring 7 disposed surrounding the cylindsr 11 is provided between the primary valve 4 and the bottom of the frame 3.
Fig. 2 shows a valve in a closed state. When the temperature of the coolant raises in excess o~ a predetermined value of the thermostat, the wax 10 expands. This forces the xubber seal spool 9 against the steel piston 8. As the wax squeezes the rubber seal spool 9 around the piston 8, the wax 10 overcomes the coil spring 7 and th~ thermo-sensitive device 5 moves downward, thereby opening the valve 4. When the thermostat cools, the wax 10 contracts. Then the coil spring 7 returns the valve to the closed position as `~ 15 shown in Fig. 2. Since a space 13 is formed in the seal spool 9 at the bottom thereof, the valve 4 is securely pressed against the seat 1.
l i Referring to Fig. 6 showing a main part of the present invention, the seal packing 15 is a double 0-ring seal device. The seal device comprises an annularseparator 20 slidably provided in a recess formed in the guide member 6 and mounted on the piston 8, a pair of 0-rings 21 disposed on opposite sides of the separator 20, a fixed cover 22, and a peripheral flange 23 inwardly , 25 deformed by a predetermined oil pressure to fix the cover 22. By adjusting the thickness of the annular '` separator 20, an optimum compression state of each o-ring can be provided.
By such a double O-ring seal device, entrances , 30 of coolant and foreign materials can be perfectly ,i,. ~
` prevented.
' '.i~:
.
", ~;j : .., -` 1 324596 Figs. 3 and 4 show a conventional thermostat.
A coolant is inducted in space 13 in the seal spool 9.
Fig. 5 shows a valve lift curve A of the thermostat of the present invention shown in Figs. 1 and 2 and a valve lift curve B of the thermostat shown in Figs. 3 and 4.
The valve 4 of the thermostat of FigO 2 begins to open at 88C and fully opens at 100C (point D) where the valve lift is 8.5 mm. Thereafter the valve is lifted by i a small increment (0.07 mm per 1C) until 130C by 10: thermal expansion of the wax 10.
On the othex hand, the valve 4 of the thermostat of Fig. 3 in which the coolant is inducted in the seal spool 9 is opened at about 84C lower than that of the thermostat of the present invention by 4C. The full open valve lift becomes 10.1 mm. Further, in the closing state, the valve 4 is not engaged with the valve seat 1, maintaining a gap of about 0.5 mm between the valve and the seat. Accordingly, the engine is ~; overcooled.
3~
In accordance with the present invention, the valve lift is constant. Accordingly, the axial length 3~ of the seal spool can be reduced. Referring to Fig. 6, the length H of the axial hole of the seal spool is expressed as follows.
H = L + ~
where L is the full open valve lift.
In the thermostat of the present invention, the l~ value a can be set to a small value, for example about 1.4 times as large as the diameter of the piston 8, thereby reducing the axial length of seal spool.
~;~ Further, it is possible to set the full open valve lift to a higher point than the point D (Fig. 5), such as for :~
., ., . ~ ~ . . .
. . , . : : , example at a point E where the valve lift change is very small, so that reliable operation is expected.
~` While the invention has been described in conjunction with preferred specific embodiments thereof, ., 5 it will be understood that this description is intended ~ to illustrate and not limit the scope of the invention, ;j which is defined by the following claim.
,~
J
~;`
. .
~:
~"
.i~, .,., ~
,~.j , :.i .~
.`j , ,1 '~'"
.~i"~ .
''~'':
'..' ,"
.~.. , . . ` . . . ~ : . .. . . .. . ... .
The present invention relates to a wax-pellet thermostat for automotive engines.
The conventional wax-pellet thermostat comprises a thermo-sensitive device and a valve device~
The thermo-sensitive device includes a steel piston, a guide member slidably engaged with the piston, a rubber ~j seal spool around the piston, and a wax. The piston is sealed by a sealing device provided in the guide member.
~! However, if the sealing device deteriorates, a space in the seal spool is communicated with a coolant passage.
Under such a condition, when the temperature of coolant rapidly decreases ~rom high temperature (about 100C) to lo~ temperature (bslow 40C), the space in the seal spool becomes a vacuum. Accordingly, the coolant is inducted into the space. Since the seal spool tightly grips the piston, the coolant in the space cannot be discharged. As described hereinafter, the valve is ';~ slightly raised by the coolant in the space, which ~'~ causes the opening temperature of the valve to decrease.
As a result, the engine is overcooled, thereby reducing ,. .
^~ 25 the thermal efficiency of the engine and increasing the amount of emissions. The amount of the coolant in the ~J space increases with time, so that the valvs lift increases, which causes engine trouble.
;~:
i~ An object of the invention is to provide a thermostat which may prevent the induction of coolant.
..:~:
According to the present invention, there is provided a thermostat having a housing having a valve seat, a piston sacured to the housin~, a guide member . .
,, .
1 32~596 slidably mounted on the piston, a valve secured to the guide member, a seal spool secured to the guide member around a lower portion of the piston, a heat conductive cylinder secured to the guide member and surrounding the seal spool, and a wax provided in the cylinder.
The thermostat has a seal device provided in the guide member at a top portion thereof around the i piston so as to prevent the enter of coolant.
: ;
These and other objects and features of the present invention will become more apparent from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1 and 2 are sectional views of a thermostat of the present invention;
Figs. 3 and 4 are sectional views of a conventional thermostat;
Fig. 5 is a graph showing valve lifts of the ~ thermo~tat of the present invention and conventional one j ~ 20 with respect to temperature; and Fig. 6 shows the operation of the thermostat of ',; the present invention.
i DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
;1 Referring to Figs. 1 and 2, the thermostat of the present invention comprises a housing 2 forming a '! valve seat 1, a frame 3 secured to the housing 2~ A
thermo-sensitive device 5 comprises a steel piston 8 secured to the housing 2 at a top 12, guide member 6 slidably engaged with the piston 8, primary valve 4 secured to the guide member 6, heat conductive cylinder 11 secured to the guide member 6, rubber seal spool 9 secured to the guide member 6, wax pellet 10 provided in ~, .
:, . . , . : .: . : ::: .
:` ` 1 324596 :
the cylinder 11, and seal packing 15 for preventing count~r flow of coolant. A return coil spring 7 disposed surrounding the cylindsr 11 is provided between the primary valve 4 and the bottom of the frame 3.
Fig. 2 shows a valve in a closed state. When the temperature of the coolant raises in excess o~ a predetermined value of the thermostat, the wax 10 expands. This forces the xubber seal spool 9 against the steel piston 8. As the wax squeezes the rubber seal spool 9 around the piston 8, the wax 10 overcomes the coil spring 7 and th~ thermo-sensitive device 5 moves downward, thereby opening the valve 4. When the thermostat cools, the wax 10 contracts. Then the coil spring 7 returns the valve to the closed position as `~ 15 shown in Fig. 2. Since a space 13 is formed in the seal spool 9 at the bottom thereof, the valve 4 is securely pressed against the seat 1.
l i Referring to Fig. 6 showing a main part of the present invention, the seal packing 15 is a double 0-ring seal device. The seal device comprises an annularseparator 20 slidably provided in a recess formed in the guide member 6 and mounted on the piston 8, a pair of 0-rings 21 disposed on opposite sides of the separator 20, a fixed cover 22, and a peripheral flange 23 inwardly , 25 deformed by a predetermined oil pressure to fix the cover 22. By adjusting the thickness of the annular '` separator 20, an optimum compression state of each o-ring can be provided.
By such a double O-ring seal device, entrances , 30 of coolant and foreign materials can be perfectly ,i,. ~
` prevented.
' '.i~:
.
", ~;j : .., -` 1 324596 Figs. 3 and 4 show a conventional thermostat.
A coolant is inducted in space 13 in the seal spool 9.
Fig. 5 shows a valve lift curve A of the thermostat of the present invention shown in Figs. 1 and 2 and a valve lift curve B of the thermostat shown in Figs. 3 and 4.
The valve 4 of the thermostat of FigO 2 begins to open at 88C and fully opens at 100C (point D) where the valve lift is 8.5 mm. Thereafter the valve is lifted by i a small increment (0.07 mm per 1C) until 130C by 10: thermal expansion of the wax 10.
On the othex hand, the valve 4 of the thermostat of Fig. 3 in which the coolant is inducted in the seal spool 9 is opened at about 84C lower than that of the thermostat of the present invention by 4C. The full open valve lift becomes 10.1 mm. Further, in the closing state, the valve 4 is not engaged with the valve seat 1, maintaining a gap of about 0.5 mm between the valve and the seat. Accordingly, the engine is ~; overcooled.
3~
In accordance with the present invention, the valve lift is constant. Accordingly, the axial length 3~ of the seal spool can be reduced. Referring to Fig. 6, the length H of the axial hole of the seal spool is expressed as follows.
H = L + ~
where L is the full open valve lift.
In the thermostat of the present invention, the l~ value a can be set to a small value, for example about 1.4 times as large as the diameter of the piston 8, thereby reducing the axial length of seal spool.
~;~ Further, it is possible to set the full open valve lift to a higher point than the point D (Fig. 5), such as for :~
., ., . ~ ~ . . .
. . , . : : , example at a point E where the valve lift change is very small, so that reliable operation is expected.
~` While the invention has been described in conjunction with preferred specific embodiments thereof, ., 5 it will be understood that this description is intended ~ to illustrate and not limit the scope of the invention, ;j which is defined by the following claim.
,~
J
~;`
. .
~:
~"
.i~, .,., ~
,~.j , :.i .~
.`j , ,1 '~'"
.~i"~ .
''~'':
'..' ,"
.~.. , . . ` . . . ~ : . .. . . .. . ... .
Claims
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A thermostat having a housing having a valve seat, a piston secured to the housing at one end thereof, a guide member axially slidably mounted on the piston, a valve secured to the guide member at the outside of the member, a seal spool secured to the guide member at a lower portion thereof so as to surround the other end of the piston, a heat conductive cylinder secured to the guide member and surrounding the seal spool, and a wax provided in the cylinder, the thermostat comprising:
a seal device provided in the guide member at a top portion thereof around the piston, the seal device comprising an annular separator slidably mounted on the piston, and at least one O-ring provided adjacent the annular separator.
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A thermostat having a housing having a valve seat, a piston secured to the housing at one end thereof, a guide member axially slidably mounted on the piston, a valve secured to the guide member at the outside of the member, a seal spool secured to the guide member at a lower portion thereof so as to surround the other end of the piston, a heat conductive cylinder secured to the guide member and surrounding the seal spool, and a wax provided in the cylinder, the thermostat comprising:
a seal device provided in the guide member at a top portion thereof around the piston, the seal device comprising an annular separator slidably mounted on the piston, and at least one O-ring provided adjacent the annular separator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000615782A CA1324596C (en) | 1986-06-12 | 1990-07-06 | Wax-pellet thermostat |
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61-134821 | 1986-06-12 | ||
| JP61134821A JPS62293325A (en) | 1986-06-12 | 1986-06-12 | Wax type thermostat |
| JP61-262744 | 1986-11-06 | ||
| JP61262744A JPS63120978A (en) | 1986-11-06 | 1986-11-06 | Wax type thermostat |
| JP62052883A JPS63219975A (en) | 1987-03-10 | 1987-03-10 | Wax type thermostat |
| JP62-052883 | 1987-03-10 | ||
| CA000539331A CA1284793C (en) | 1986-06-12 | 1987-06-10 | Wax-pellet thermostat |
| CA000615782A CA1324596C (en) | 1986-06-12 | 1990-07-06 | Wax-pellet thermostat |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000539331A Division CA1284793C (en) | 1986-06-12 | 1987-06-10 | Wax-pellet thermostat |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1324596C true CA1324596C (en) | 1993-11-23 |
Family
ID=27426475
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000615782A Expired - Fee Related CA1324596C (en) | 1986-06-12 | 1990-07-06 | Wax-pellet thermostat |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1324596C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113001831A (en) * | 2019-12-20 | 2021-06-22 | 中国石油天然气股份有限公司 | Wax ball manufacturing method |
-
1990
- 1990-07-06 CA CA000615782A patent/CA1324596C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113001831A (en) * | 2019-12-20 | 2021-06-22 | 中国石油天然气股份有限公司 | Wax ball manufacturing method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0249451B1 (en) | Wax-pellet thermostat | |
| US5033865A (en) | Thermo-actuator | |
| EP0573399B1 (en) | Trim for ANSI class V shut off valves | |
| US8752807B2 (en) | Seat block and valve device | |
| US4895229A (en) | Hydraulic shock absorber | |
| US6142037A (en) | Transmission check valve | |
| US4128203A (en) | Four-port thermally responsive valve | |
| JP2019516925A (en) | Thermostatic valve | |
| US4165035A (en) | Thermally actuated valve for plural fluid sources | |
| US5791630A (en) | Flow control valve | |
| US4685489A (en) | Valve assembly and compressor modulation apparatus | |
| US4986796A (en) | Hydraulic autotensioner | |
| CA1324596C (en) | Wax-pellet thermostat | |
| CA2093870A1 (en) | Thermo-actuator | |
| CA1260354A (en) | Disk type steam trap | |
| US5119061A (en) | Thermo-actuator | |
| JP3955819B2 (en) | Pressure relief device with integrated gasket | |
| CA2010049C (en) | Wax-pellet thermostat | |
| US4978060A (en) | Engine coolant thermostat with pressure relief feature | |
| GB2253264A (en) | A thermostatic valve | |
| US4778351A (en) | Unloader, and in combination with an air compressor inlet housing | |
| GB2117494A (en) | A valved closure cap | |
| US4285467A (en) | Three-port thermally responsive valve | |
| US4239152A (en) | Temperature responsive valve assembly | |
| JPH10184825A (en) | Hydraulic auto-tensioner |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |