CA1197542A - Engine block heater with integrated thermostatic control - Google Patents
Engine block heater with integrated thermostatic controlInfo
- Publication number
- CA1197542A CA1197542A CA000393936A CA393936A CA1197542A CA 1197542 A CA1197542 A CA 1197542A CA 000393936 A CA000393936 A CA 000393936A CA 393936 A CA393936 A CA 393936A CA 1197542 A CA1197542 A CA 1197542A
- Authority
- CA
- Canada
- Prior art keywords
- engine block
- thermostat
- block
- temperature
- opening
- 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
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
- F02N19/00—Starting aids for combustion engines, not otherwise provided for
- F02N19/02—Aiding engine start by thermal means, e.g. using lighted wicks
- F02N19/04—Aiding engine start by thermal means, e.g. using lighted wicks by heating of fluids used in engines
- F02N19/10—Aiding engine start by thermal means, e.g. using lighted wicks by heating of fluids used in engines by heating of engine coolants
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
- F01P11/14—Indicating devices; Other safety devices
- F01P11/20—Indicating devices; Other safety devices concerning atmospheric freezing conditions, e.g. automatically draining or heating during frosty weather
Abstract
ABSTRACT OF THE DISCLOSURE
This invention relates to a method and apparatus for heating liquid-cooled, automotive engines during cold weather conditions. The method comprises heating the liquid coolant of the engine with an electric heater emplaced in the coolant containing cooling jacket of the engine block, measuring the engine block temperature with a temperature sensing device and regulating the passage of electrical current to the electric heater in accordance with predetermined high and low block temperature settings.
This invention relates to a method and apparatus for heating liquid-cooled, automotive engines during cold weather conditions. The method comprises heating the liquid coolant of the engine with an electric heater emplaced in the coolant containing cooling jacket of the engine block, measuring the engine block temperature with a temperature sensing device and regulating the passage of electrical current to the electric heater in accordance with predetermined high and low block temperature settings.
Description
FIELD OF THE INVE~TION
This invention relates to the electric heating of automobile engines during cold weather condition3.
More par-ticularly, the inventiorl relates to an electric heating element which is placed within an engine bLock through a frost plug, and the temperature control oE the heater using a unique arrangement that integrates an engine block thermo~tat to the block heater.
BACKGROUND OF THE INVE~TION
Presently, a~tomobiles which use electrical block heaters during cold weather conditions are simply plugged in to an electrical outlet as required. There is no control over electrical po~er consumption or engine temperature. With a fixed electrical current draw, engine temperatures can be higher than required for effective engine starting, thus wasting energy.
Further, block heaters may be plugged in unnecessarily on days when a block heater i9 not needed, thereby contributing to energy waste. For instance, an ~ automobile owner could plug in his block heater for a full day unnecessarily because he was predicting cold weather for the next day, when in fact it might turn out to be mild. His tendency would at most -times be to err on the conservative side, thus leading to a waste of energy. By way of specific example, on the coldest night of the year in Saskatchewan (-30C -to ~40C), virtually every vehicle would have its block heater plugged in for the night to an electrical power source as soon as the driver parked the vehicle, usually before the dinner hour. This would be the case even though tests under such temperatures have clearly shown that because of residual heat stored in the engine block the block heater need not be pluyged in until the engine had been stopped for at least Eour hours. IE the plug-in was made at about 18()0 hours, Eor example, 500 to 750 W of electrical power draw per automobile would be unnecessarily added to the peak load oE the electrical utility at that time of day. This can be a signiEicant problem for the electrical utility when tens oE thousands of heaters are plugged in at approximately the same time. The problem is compounded because it generally occurs when power draw by the public is at its peak due to lights and stoves being turned on in preparation Eor dinner.
Several thermostatically controlled block heater designs are known to the applicant but most are temperature controlled using a bellows apparatus that expands when heatedO Gratsinger (United States Patent No. 2,505,286) uses a bimetal temperature control but it is connected to a heater that is external to the block of the engine and is for temporary installation only.
As well, devices are on the market that attempt to attenuate the block heater load~ For example, a device called Power Saver Cord* is manufact-ured and sold by Temro Automotive, Winnipeg, Manitoba.
These devices measure the engine coolant temperature in the heater hose and switch the block heater ON and OFF
accordingly. But this device is an "add-on" type~ which is an inconvenience and a nuisance. ~lso, measurement of the engine block temperature is not taken.
*Trade Mark S[lM;lAR~ OF THE INVENTION
The applicant's invention comprises a thermo-stat and a block heater integrated as one unit with only a small increase in overall si7e compared to a conven-tional block heater.
The invention is directed to an apparatus for heating liquid~cooled, automotive engines adapted for installation in an opening in the coolant-containing jacket of the engine block wherein the apparatus is an integral unit comprising a body member adapted to seal the opening and having an electric heating element moun-ted thereon to extend into the interior o~ the engine block~ a thermostat electrically connected to the heating element and responsive to the temperature of the engine block to electrically connect the heating element to a source of electric energy when the temperature of the engine block is below a lower limit and to discon-nect ~he heating element from the source of electric energy when the temperature o~ the engine block is above an upper limit, means for thermally isolating the ther-mostat from the electric heating element and means for securing the apparatus in the opening. According to one aspect of the invention, the apparatus may further include heat-conducting means to conduct heat ~rom the engine block to the the~mostat which may be a base element on which the th0rmostat is mounted and which is adapted to directly contact the jacket of the engine block when the apparatus is installed in the engine block. The apparatus may be installed in a frost plug of the internal combustion engine block. A hollow space formed in the body member or heat-insulating material may comprise the means for thermally isolating -the ther-mostat. According to a ~urther aspect of the invention, , -the apparatus may comprise a housing to externally cover the thermostat and isolate it from external ternperature changes. Further, the apparatus may be secured in the opening by means oE a retaining bar adapted to be c~rawn against the i.nterior surface of the jacket adjacent the opening upon tightening of an external nut on a bolt p~ssing through the retaining bar and the apparatus~
DRAWINGS
In the drawings:
FIGURE 1 represents two graphical depicti.ons of ~ngine Block temperature against Engine Temperature Cooldown Rate with Ambient Air Temperatures respectively of -20C and -30C;
FIGURE 2 represents a side elevation view of the integrated device;
FIGURE 3 represents a frontal elevation view of the integrated device;
FIGURE 4 represents a section view taken along Section A-A of FIGURE 3;
FIGURE 5 represents a section view taken along Section B B of FIGURE 2; and FIGURE 6 represents a graphical depiction of Ambient Air Temperature against Thermostatic Block Heating Temperature Histories.
FIGURE 7 represents a graphical depiction of Ambient Air Temperature, Block Surface Temperature and Power Consump-tion against Time.
DETAILED DESCRIPTION OF THE INVENTION
FIGURE 1 represents a graphical depiction of rate of engine temperature cool down at two di~ferent ambient temperatures (-20C and -30C). Results are shown for eight cylinder, six cylinder and four cylinder eng.ines. r~1e cool down rate is slower for e.ight cylil1der engines presumabl~ because of larger enc,sine size (gre~l-ter heat capacity) an(l larger coolant volurne.
The graphs of experimen-tal results demonstrate that the 5. average ~ime for the englne temperature to cool -from ~pproximately 70C to ~10C at the respective ambient temperatures is about four hours. An engine can usually be started readily at temperatures above -10C. Thus, when the block heater is plucsced in at any time duriny 10 this cool down period, even at an ambient telrlperature o~
~30r'C, energy ls wasted~
The invention, as shown in FIGURES 2 and ~, consists o a cornbina-tion of an electric heatirl~
elemen-t l, shielding insulation 2, a heat conducting disc 3, a thern1ostat 4 and wiring 5 to conrlect Lhe thermostat 4 in series with the heater l. The therlnostat 4 uses a bimetal disc or strip to open a set of electrical current points or co1tacts ~not shown) . which are h~!at sensi~ive and can be set to interrupt the : ~0 electrical current at a prescribed block temperature, ~or example, about 0C. The means by which the current is controlled by the thermostat 4 is lesi-~ned for small ss?aces an~ is available from a nurnber of sources. For exalnple, Texas Instruments Incorporated distributes ~5 various ~ixed ternperat~re thermostats which are designed for use where space is limited.
FIG~5RES 3 and 5 show respectively ~.rorltral elevatio-1 and section views of -the inventlor1, incl~l(.1ing clelnerlt l, disc 3, t'hern~ostclt 4/ holdlll~3 dlsc 6 and 30 retainincs ~ar 8.
~ .
As seen in FIGURE 4, the invention is ti~htly helcl in ~ sized circular hole in the en~ine block 10 by a holding disc 6 (sized to :Eit into the hole in the engirle block 10), a retaining bol.t 7 extending throuyh the block 10 (by way of sleeve 13) and a retaininc3 bar 8 on ~he inside of the block :lO penetrated by the bolt 7, and a butterfly nut 17. An O-ring g is fitted between the block 10 and di.sc 6 to ensure a liquid tight engine coolant seal. ~ sealing washer 12 i8 also used to preveot en~ine coolant leaking khrough the sleeve 13.
~he therrnostat 4 is held in place by an enclosin~
cover 11 (preferably cons-truc-ted of rubber or plastic~
and a retaining nut i5. In-ternal retaining nut 16 i5 used to hold together the inner assembly which consists 1.5 of the heat conductin~ plate 3, the insulat.ing material 2 and the holding disc 6. Retaining bar 8 is longer .in length than the diameter of the circu].ar hole opening and thereby firmiy fastens the device -to the en~ine block 10 when butter-Ely nut 17 is securely ~0 tight2ned. Re-taining bar 8 is also suffici~ntly short to allow it to be inserted into the circular hole openiny upon installation.
The function of insulation 2 and dead ai.r space 14 in combination is to isolate the heater element ~5 1. and en~ine coolant from -the heat conducting disc 3 which is in direct contact with block 10. Insul~ltion 2 may be a r:igid fibrous glass insulating l~aterial which has su~er:ior insulating properties. Other insulating materiaLs which can tolerate en~ine block temperature ancl provide superior insulatlon quali~i.es may be used.
. ~, . . .
p~ ,.
The s~ace L4 can also be packed with a sui-table insulating material, either the s~me as or lifferent from insulat:ion 2~ With a conventional block heater, tests have shown ~hat sensing the temperature on the heater flange of the block heater tencls to provide a localize~ readin~ ~nd to thereby inhibit proper cycling of the heater. Because only a locali~ed warm portion is being sensed, the.heater tends to be shut oEE before the overall engine block and coolant are up to temperature (-10C). By insulating heat conduction from the hea-ter element 1 and the coolant t.o the conducting disc 3, thermostat 4 tends not to be sensitive to local heating caused by the heater element 1 but tends t.o be sensi.tive to the overall block temperature, whicll tends ~o be relAtively close to the average coolan-t temQerature.
The thermostat 4 is also isolated from the cold ambient air ternperature by the rubber or plastic cover 11, thereby reducing the sensitivity o~ the : therlnostat 4 ~o outside temperatures, and erl3uring that t.he thermostat 4 more closely measures engine block 10 and coolant temperature.
Example 1 The thermostatically controlled block heater was installed in a 4~cylinder engine block in order to test i-ts response to changes in envirollment -temperature.
The engine block was instrumented with thermocouples and the power to the block heater monitored continuousLy during tests that were conducted in an envrironmental chamber. FLG~RE 7 shows the results oE reducing the ellvironlnental chamber temperature in s-teps Erom -10C to _ 7 _ .
~, %
-40C. It was observed that the surface -temperature of the engin~ block wa~ maintained between 0 and -10C by the cycling of the thermos-tat. Also, as the ~nvi.ronment temperature was reduced, the duty cycle of the block heater increased, thereby responding to the increased heating load on the block.
The surface temperature of the enyine block shown in FIGURE 7 was chosen -to represent the average tempera-ture o the block. In fact, because of natural convection, the hotter coolant rises to the top and the colder coolant settles at the bottom of the block resulting in stratification in temperatures. In addition, the block heater itself is a localized h.igher temperature area.
Table 1 Block Heater Response Due to Changing Temperature Environment Duty Cycle Percent Coolant Temperature Chamber Time Time O~ ApproxO
Temperature O~ OFF Time Average Min. Max.
(F) (C) (min.) (min.) (%) ~C) (C) _C) 12 -11 2.0 60 3 -10 -12 14 -10 2.0 35 5 - 8 - 9 0 -17 2~0 6.8 23 - 7 -11 6 3 -16 2.0 7.2 22 - 4 -11 8 -12 ~24 2.6 3.6 42 - 7 -12 7 -1~ -27 2.8 3.2 47 - 7 -13 3
This invention relates to the electric heating of automobile engines during cold weather condition3.
More par-ticularly, the inventiorl relates to an electric heating element which is placed within an engine bLock through a frost plug, and the temperature control oE the heater using a unique arrangement that integrates an engine block thermo~tat to the block heater.
BACKGROUND OF THE INVE~TION
Presently, a~tomobiles which use electrical block heaters during cold weather conditions are simply plugged in to an electrical outlet as required. There is no control over electrical po~er consumption or engine temperature. With a fixed electrical current draw, engine temperatures can be higher than required for effective engine starting, thus wasting energy.
Further, block heaters may be plugged in unnecessarily on days when a block heater i9 not needed, thereby contributing to energy waste. For instance, an ~ automobile owner could plug in his block heater for a full day unnecessarily because he was predicting cold weather for the next day, when in fact it might turn out to be mild. His tendency would at most -times be to err on the conservative side, thus leading to a waste of energy. By way of specific example, on the coldest night of the year in Saskatchewan (-30C -to ~40C), virtually every vehicle would have its block heater plugged in for the night to an electrical power source as soon as the driver parked the vehicle, usually before the dinner hour. This would be the case even though tests under such temperatures have clearly shown that because of residual heat stored in the engine block the block heater need not be pluyged in until the engine had been stopped for at least Eour hours. IE the plug-in was made at about 18()0 hours, Eor example, 500 to 750 W of electrical power draw per automobile would be unnecessarily added to the peak load oE the electrical utility at that time of day. This can be a signiEicant problem for the electrical utility when tens oE thousands of heaters are plugged in at approximately the same time. The problem is compounded because it generally occurs when power draw by the public is at its peak due to lights and stoves being turned on in preparation Eor dinner.
Several thermostatically controlled block heater designs are known to the applicant but most are temperature controlled using a bellows apparatus that expands when heatedO Gratsinger (United States Patent No. 2,505,286) uses a bimetal temperature control but it is connected to a heater that is external to the block of the engine and is for temporary installation only.
As well, devices are on the market that attempt to attenuate the block heater load~ For example, a device called Power Saver Cord* is manufact-ured and sold by Temro Automotive, Winnipeg, Manitoba.
These devices measure the engine coolant temperature in the heater hose and switch the block heater ON and OFF
accordingly. But this device is an "add-on" type~ which is an inconvenience and a nuisance. ~lso, measurement of the engine block temperature is not taken.
*Trade Mark S[lM;lAR~ OF THE INVENTION
The applicant's invention comprises a thermo-stat and a block heater integrated as one unit with only a small increase in overall si7e compared to a conven-tional block heater.
The invention is directed to an apparatus for heating liquid~cooled, automotive engines adapted for installation in an opening in the coolant-containing jacket of the engine block wherein the apparatus is an integral unit comprising a body member adapted to seal the opening and having an electric heating element moun-ted thereon to extend into the interior o~ the engine block~ a thermostat electrically connected to the heating element and responsive to the temperature of the engine block to electrically connect the heating element to a source of electric energy when the temperature of the engine block is below a lower limit and to discon-nect ~he heating element from the source of electric energy when the temperature o~ the engine block is above an upper limit, means for thermally isolating the ther-mostat from the electric heating element and means for securing the apparatus in the opening. According to one aspect of the invention, the apparatus may further include heat-conducting means to conduct heat ~rom the engine block to the the~mostat which may be a base element on which the th0rmostat is mounted and which is adapted to directly contact the jacket of the engine block when the apparatus is installed in the engine block. The apparatus may be installed in a frost plug of the internal combustion engine block. A hollow space formed in the body member or heat-insulating material may comprise the means for thermally isolating -the ther-mostat. According to a ~urther aspect of the invention, , -the apparatus may comprise a housing to externally cover the thermostat and isolate it from external ternperature changes. Further, the apparatus may be secured in the opening by means oE a retaining bar adapted to be c~rawn against the i.nterior surface of the jacket adjacent the opening upon tightening of an external nut on a bolt p~ssing through the retaining bar and the apparatus~
DRAWINGS
In the drawings:
FIGURE 1 represents two graphical depicti.ons of ~ngine Block temperature against Engine Temperature Cooldown Rate with Ambient Air Temperatures respectively of -20C and -30C;
FIGURE 2 represents a side elevation view of the integrated device;
FIGURE 3 represents a frontal elevation view of the integrated device;
FIGURE 4 represents a section view taken along Section A-A of FIGURE 3;
FIGURE 5 represents a section view taken along Section B B of FIGURE 2; and FIGURE 6 represents a graphical depiction of Ambient Air Temperature against Thermostatic Block Heating Temperature Histories.
FIGURE 7 represents a graphical depiction of Ambient Air Temperature, Block Surface Temperature and Power Consump-tion against Time.
DETAILED DESCRIPTION OF THE INVENTION
FIGURE 1 represents a graphical depiction of rate of engine temperature cool down at two di~ferent ambient temperatures (-20C and -30C). Results are shown for eight cylinder, six cylinder and four cylinder eng.ines. r~1e cool down rate is slower for e.ight cylil1der engines presumabl~ because of larger enc,sine size (gre~l-ter heat capacity) an(l larger coolant volurne.
The graphs of experimen-tal results demonstrate that the 5. average ~ime for the englne temperature to cool -from ~pproximately 70C to ~10C at the respective ambient temperatures is about four hours. An engine can usually be started readily at temperatures above -10C. Thus, when the block heater is plucsced in at any time duriny 10 this cool down period, even at an ambient telrlperature o~
~30r'C, energy ls wasted~
The invention, as shown in FIGURES 2 and ~, consists o a cornbina-tion of an electric heatirl~
elemen-t l, shielding insulation 2, a heat conducting disc 3, a thern1ostat 4 and wiring 5 to conrlect Lhe thermostat 4 in series with the heater l. The therlnostat 4 uses a bimetal disc or strip to open a set of electrical current points or co1tacts ~not shown) . which are h~!at sensi~ive and can be set to interrupt the : ~0 electrical current at a prescribed block temperature, ~or example, about 0C. The means by which the current is controlled by the thermostat 4 is lesi-~ned for small ss?aces an~ is available from a nurnber of sources. For exalnple, Texas Instruments Incorporated distributes ~5 various ~ixed ternperat~re thermostats which are designed for use where space is limited.
FIG~5RES 3 and 5 show respectively ~.rorltral elevatio-1 and section views of -the inventlor1, incl~l(.1ing clelnerlt l, disc 3, t'hern~ostclt 4/ holdlll~3 dlsc 6 and 30 retainincs ~ar 8.
~ .
As seen in FIGURE 4, the invention is ti~htly helcl in ~ sized circular hole in the en~ine block 10 by a holding disc 6 (sized to :Eit into the hole in the engirle block 10), a retaining bol.t 7 extending throuyh the block 10 (by way of sleeve 13) and a retaininc3 bar 8 on ~he inside of the block :lO penetrated by the bolt 7, and a butterfly nut 17. An O-ring g is fitted between the block 10 and di.sc 6 to ensure a liquid tight engine coolant seal. ~ sealing washer 12 i8 also used to preveot en~ine coolant leaking khrough the sleeve 13.
~he therrnostat 4 is held in place by an enclosin~
cover 11 (preferably cons-truc-ted of rubber or plastic~
and a retaining nut i5. In-ternal retaining nut 16 i5 used to hold together the inner assembly which consists 1.5 of the heat conductin~ plate 3, the insulat.ing material 2 and the holding disc 6. Retaining bar 8 is longer .in length than the diameter of the circu].ar hole opening and thereby firmiy fastens the device -to the en~ine block 10 when butter-Ely nut 17 is securely ~0 tight2ned. Re-taining bar 8 is also suffici~ntly short to allow it to be inserted into the circular hole openiny upon installation.
The function of insulation 2 and dead ai.r space 14 in combination is to isolate the heater element ~5 1. and en~ine coolant from -the heat conducting disc 3 which is in direct contact with block 10. Insul~ltion 2 may be a r:igid fibrous glass insulating l~aterial which has su~er:ior insulating properties. Other insulating materiaLs which can tolerate en~ine block temperature ancl provide superior insulatlon quali~i.es may be used.
. ~, . . .
p~ ,.
The s~ace L4 can also be packed with a sui-table insulating material, either the s~me as or lifferent from insulat:ion 2~ With a conventional block heater, tests have shown ~hat sensing the temperature on the heater flange of the block heater tencls to provide a localize~ readin~ ~nd to thereby inhibit proper cycling of the heater. Because only a locali~ed warm portion is being sensed, the.heater tends to be shut oEE before the overall engine block and coolant are up to temperature (-10C). By insulating heat conduction from the hea-ter element 1 and the coolant t.o the conducting disc 3, thermostat 4 tends not to be sensitive to local heating caused by the heater element 1 but tends t.o be sensi.tive to the overall block temperature, whicll tends ~o be relAtively close to the average coolan-t temQerature.
The thermostat 4 is also isolated from the cold ambient air ternperature by the rubber or plastic cover 11, thereby reducing the sensitivity o~ the : therlnostat 4 ~o outside temperatures, and erl3uring that t.he thermostat 4 more closely measures engine block 10 and coolant temperature.
Example 1 The thermostatically controlled block heater was installed in a 4~cylinder engine block in order to test i-ts response to changes in envirollment -temperature.
The engine block was instrumented with thermocouples and the power to the block heater monitored continuousLy during tests that were conducted in an envrironmental chamber. FLG~RE 7 shows the results oE reducing the ellvironlnental chamber temperature in s-teps Erom -10C to _ 7 _ .
~, %
-40C. It was observed that the surface -temperature of the engin~ block wa~ maintained between 0 and -10C by the cycling of the thermos-tat. Also, as the ~nvi.ronment temperature was reduced, the duty cycle of the block heater increased, thereby responding to the increased heating load on the block.
The surface temperature of the enyine block shown in FIGURE 7 was chosen -to represent the average tempera-ture o the block. In fact, because of natural convection, the hotter coolant rises to the top and the colder coolant settles at the bottom of the block resulting in stratification in temperatures. In addition, the block heater itself is a localized h.igher temperature area.
Table 1 Block Heater Response Due to Changing Temperature Environment Duty Cycle Percent Coolant Temperature Chamber Time Time O~ ApproxO
Temperature O~ OFF Time Average Min. Max.
(F) (C) (min.) (min.) (%) ~C) (C) _C) 12 -11 2.0 60 3 -10 -12 14 -10 2.0 35 5 - 8 - 9 0 -17 2~0 6.8 23 - 7 -11 6 3 -16 2.0 7.2 22 - 4 -11 8 -12 ~24 2.6 3.6 42 - 7 -12 7 -1~ -27 2.8 3.2 47 - 7 -13 3
-2~ -33 4.0 2.6 60 - 7 -16 5 -40 -40 7.2 2.0 78 - 8 -17 4 As shown in Table 1, with the unit used, the tests indicate that the -thermostatically controlled block heater will maintain the engine coolant ~7~
temperature between -17C and -~8~ ~or all environmental chamber temperatures.
The device, by its desi~n, controls the coolant temperature in the engine block to a temperature within the range -10C to 10C, which is usually suficiently hiyh to promote easy engine starting. By not permittin~ the engine to reach temperatures higher than necessary for s-tart.i.ng, energy is conse:rved. In fact, because o~ heat stored in the engine block, the block heater in -30C weather does not as a rule consume electricity for about ~ hours after the engine has been stopped. Consequently, because most auto-mobiles are "plugged in" after driving home ~rom the of.ice, the use of the applicant's device proportion-; 15 ately reduces the peak load drawn on the elec-trical :~ power utility (a most desirable objective from the taxpayer's and ut.ility's point oE view)~
The upper and lower temperature limits o~ the thermostat may be changed as required thereby altering the duty cycle and the energy consumption of the device.
The applicant's device is a distinct improve-ment on the presently available add-on thermostat devices because the customer cannot easily disconnect or remove the thermostat component. This might happen on very cold days, for example, because the owner, in taking the saEe approach, may not trust an add-on device and simply disconnect i-t. He does this at the precise time that max.imum power draws are being made on the electrical power utility. Power draws tend to be largest on the coldest days. Further, the reduced cost of production of one device compared to two means lower initial and installation costs to the cu~tomer. The unit package is not significantly larger than present commercially acceptable bloclc heaters and this should result in higher customer acceptance because the device can be installed in place o~ existing block heaters.
Some specific benefits of this unique combination are:
(l) '~le integral device has higher reliability and ]ower maintenance;
(2) The device can be easily installed at reduced cost because the device is unitary in construction (inte~rated block heater and thermostat) and is installed as a unit instead of two separate units (block heater and add-on thermostat);
temperature between -17C and -~8~ ~or all environmental chamber temperatures.
The device, by its desi~n, controls the coolant temperature in the engine block to a temperature within the range -10C to 10C, which is usually suficiently hiyh to promote easy engine starting. By not permittin~ the engine to reach temperatures higher than necessary for s-tart.i.ng, energy is conse:rved. In fact, because o~ heat stored in the engine block, the block heater in -30C weather does not as a rule consume electricity for about ~ hours after the engine has been stopped. Consequently, because most auto-mobiles are "plugged in" after driving home ~rom the of.ice, the use of the applicant's device proportion-; 15 ately reduces the peak load drawn on the elec-trical :~ power utility (a most desirable objective from the taxpayer's and ut.ility's point oE view)~
The upper and lower temperature limits o~ the thermostat may be changed as required thereby altering the duty cycle and the energy consumption of the device.
The applicant's device is a distinct improve-ment on the presently available add-on thermostat devices because the customer cannot easily disconnect or remove the thermostat component. This might happen on very cold days, for example, because the owner, in taking the saEe approach, may not trust an add-on device and simply disconnect i-t. He does this at the precise time that max.imum power draws are being made on the electrical power utility. Power draws tend to be largest on the coldest days. Further, the reduced cost of production of one device compared to two means lower initial and installation costs to the cu~tomer. The unit package is not significantly larger than present commercially acceptable bloclc heaters and this should result in higher customer acceptance because the device can be installed in place o~ existing block heaters.
Some specific benefits of this unique combination are:
(l) '~le integral device has higher reliability and ]ower maintenance;
(2) The device can be easily installed at reduced cost because the device is unitary in construction (inte~rated block heater and thermostat) and is installed as a unit instead of two separate units (block heater and add-on thermostat);
(3) The device enables direct and accurate measurement of the engine block ~ temperature to be made by insulating the thermostat and temperature sensing plate from th0 heater element and the ambient environment;
(~) The device remains in place with the vehicle for use whenever the vehicle is plugged in;
(5) The device maintains engine block temperature at a level necessary for starting (~10C to -10C) and not higher, thereby conserving energy;
-- 10 ~
(6) No electrical power demand is normally made at peak use periods because the device does not draw curren-t whi.le there is a pre-determi.ned level of residual S heat in the block for -those vehicles driven home from work at noon time or in the eveni.ng;
(7) The device is moun-ted within the block thereby minimi.zing heat loss as compared to an externally mounted block heater;
and (8) The device, being small and compact can be fitted into most automobiles in place of an existing block heater.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modiEications are possible in ~he practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance deined by the following claims.
(~) The device remains in place with the vehicle for use whenever the vehicle is plugged in;
(5) The device maintains engine block temperature at a level necessary for starting (~10C to -10C) and not higher, thereby conserving energy;
-- 10 ~
(6) No electrical power demand is normally made at peak use periods because the device does not draw curren-t whi.le there is a pre-determi.ned level of residual S heat in the block for -those vehicles driven home from work at noon time or in the eveni.ng;
(7) The device is moun-ted within the block thereby minimi.zing heat loss as compared to an externally mounted block heater;
and (8) The device, being small and compact can be fitted into most automobiles in place of an existing block heater.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modiEications are possible in ~he practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance deined by the following claims.
Claims (8)
1. An apparatus for heating liquid-cooled automo-tive engines adapted for installation in an opening in the coolant-containing jacket of the engine block wherein said apparatus is an integral unit comprising:
(a) a body member adapted to seal said opening and having an electric heating element mounted thereon to extend into the inte-rior of said engine block;
(b) a thermostat electrically connected to said heating element and responsive to the temperature of said engine block to elec-trically connect said heating element to a source of electric energy when said tem-perature of said engine block is below a lower limit and to electrically disconnect said heating element from said source of electric energy when said temperature of said engine block is above an upper limit;
(c) means for thermally isolating said thermo-stat from said electric heating element;
and (d) means for securing said apparatus in said opening.
- Page 1 of Claim -
(a) a body member adapted to seal said opening and having an electric heating element mounted thereon to extend into the inte-rior of said engine block;
(b) a thermostat electrically connected to said heating element and responsive to the temperature of said engine block to elec-trically connect said heating element to a source of electric energy when said tem-perature of said engine block is below a lower limit and to electrically disconnect said heating element from said source of electric energy when said temperature of said engine block is above an upper limit;
(c) means for thermally isolating said thermo-stat from said electric heating element;
and (d) means for securing said apparatus in said opening.
- Page 1 of Claim -
2. The apparatus of claim 1 further comprising heat-conducting means adapted to conduct heat from said engine block to said thermostat.
3. The apparatus of claim 2 wherein said heat-conducting means comprises a base element on which said thermostat is mounted and which is adapted to directly contact said jacket of said engine block when said appara-tus is installed in said engine block.
4. The apparatus of claim 1, 2 or 3 wherein said opening is a frost plug of an internal combustion engine block.
5. The apparatus of claim 1, 2 or 3 wherein said means for thermally isolating said thermostat comprises a hollow space formed in said body member.
6. The apparatus of claim 1, 2 or 3 wherein said means for thermally isolating comprises heat-insulating material positioned between said thermostat and said body member.
7. The apparatus of claim 1, 2 or 3 further compri-sing a housing adapted to externally cover said thermostat and thereby isolate said thermostat from external tempera-ture changes.
- Page 2 of Claim -
- Page 2 of Claim -
8. The apparatus of claim 1, 2 or 3 wherein said means for securing said apparatus in said opening comprises a retaining bar adapted to be drawn against the interior surface of said jacket adjacent said opening upon tightening of an external nut on a bolt passing through said retaining bar and said apparatus.
- Page 3 of Claim -
- Page 3 of Claim -
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000393936A CA1197542A (en) | 1982-01-12 | 1982-01-12 | Engine block heater with integrated thermostatic control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000393936A CA1197542A (en) | 1982-01-12 | 1982-01-12 | Engine block heater with integrated thermostatic control |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1197542A true CA1197542A (en) | 1985-12-03 |
Family
ID=4121798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000393936A Expired CA1197542A (en) | 1982-01-12 | 1982-01-12 | Engine block heater with integrated thermostatic control |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1197542A (en) |
-
1982
- 1982-01-12 CA CA000393936A patent/CA1197542A/en not_active Expired
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| MKEX | Expiry |