U.S. patent application number 13/311751 was filed with the patent office on 2012-07-19 for washer fluid warming device.
This patent application is currently assigned to MURAKAMI CORPORATION. Invention is credited to Masaki KOBAYASHI, Hidenori SATO.
Application Number | 20120183281 13/311751 |
Document ID | / |
Family ID | 46472002 |
Filed Date | 2012-07-19 |
United States Patent
Application |
20120183281 |
Kind Code |
A1 |
SATO; Hidenori ; et
al. |
July 19, 2012 |
WASHER FLUID WARMING DEVICE
Abstract
A warming device capable of quickly increasing a temperature of
a washer fluid with a relatively-low current, warming a
relatively-large volume of washer fluid, and further retaining a
washer fluid in a warmed state for some time after a power supply
is turned off is provided. A warming device includes a structure in
which a small heating chamber is housed in an inner space of a
heat-retaining hot fluid storage chamber and an electric heater is
housed in an inner space of the small heating chamber. The
heat-retaining hot fluid storage chamber has a heat-insulating
structure. The small heating chamber has a moderate thermal
conductivity. A washer fluid fed from a washer tank is supplied to
the small heating chamber through the heat-retaining hot fluid
storage chamber, warmed by the heater and ejected from a washer
nozzle.
Inventors: |
SATO; Hidenori;
(Fujieda-city, JP) ; KOBAYASHI; Masaki;
(Fujieda-city, JP) |
Assignee: |
MURAKAMI CORPORATION
Shizuoka-city
JP
|
Family ID: |
46472002 |
Appl. No.: |
13/311751 |
Filed: |
December 6, 2011 |
Current U.S.
Class: |
392/441 |
Current CPC
Class: |
F24H 1/009 20130101;
F24H 1/102 20130101; B60S 1/488 20130101; F24H 1/202 20130101; F24H
9/0021 20130101 |
Class at
Publication: |
392/441 |
International
Class: |
F24H 1/18 20060101
F24H001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 13, 2011 |
JP |
2011-005277 |
Claims
1. A washer fluid warming device arranged between a washer tank and
a washer nozzle in a washer apparatus on board a vehicle, the
washer fluid warming device warming a washer fluid sent in from the
washer tank and sending the washer fluid out to the washer nozzle,
the device comprising: a heat-retaining hot fluid storage chamber
including a wall having a heat-insulating structure in which a
vacuum layer is provided between an inner wall and an outer wall
and including an inner space into which the washer fluid flowing
out of the washer tank flows as a result of a washer pump being
driven; a small heating chamber including a wall having a thermal
conductivity higher than that of the wall of the heat-retaining hot
fluid storage chamber, being housed in the inner space of the
heat-retaining hot fluid storage chamber, and further including an
inner space into which the washer fluid in the heat-retaining hot
fluid storage chamber flows as a result of the washer pump being
driven; and an electric heater housed in the inner space of the
small heating chamber, the electric heater warming the washer fluid
in the small heating chamber, wherein the inner space of the
heat-retaining hot fluid storage chamber is set to have a size
capable of accommodating a volume of washer fluid that is larger
than a volume of washer fluid that can be accommodated by the inner
space of the small heating chamber; and wherein the warmed washer
fluid flowing out of the small heating chamber is supplied to the
washer nozzle as a result of the washer pump being driven.
2. The washer fluid warming device according to claim 1, wherein
the heat-retaining hot fluid storage chamber includes an opening
that provides communication between an outer space and the inner
space thereof; wherein the small heating chamber with the electric
heater housed therein is attached to a lid that occludes the
opening; and wherein the small heating chamber is inserted into the
inner space of the heat-retaining hot fluid storage chamber from
the opening and thereby housed in the inner space of the
heat-retaining hot fluid storage chamber and the opening is
occluded by the lid.
3. The washer fluid warming device according to claim 2, wherein
the lid includes: a washer fluid inflow channel that allows the
washer fluid to flow from the outside into the heat-retaining hot
fluid storage chamber; a washer fluid outflow channel that allows
the washer fluid in the small heating chamber to flow out to the
outside; and an electric wire leading channel that allows an
electric wire for supplying power to the electric heater to be led
to the outside.
4. The washer fluid warming device according to claim 2, wherein
the small heating chamber is formed in a tubular shape extending in
a vertical direction; wherein the washer fluid warming device
further includes a plate-shaped movable throttle lid housed in the
inner space of the small heating chamber; wherein the electric
heater has a stick-like shape and is arranged along a central axis
of the tubular small heating chamber; wherein the movable throttle
lid includes a central hole, and the electric heater is inserted
through the central hole and arranged so that the movable throttle
lid can ascend/descend along the electric heater, and wherein upon
the movable throttle lid being pushed up by the washer fluid
flowing in from a lower portion of the inner space of the small
heating chamber, the movable throttle lid makes the washer fluid on
an upper side of the movable throttle lid flow out of the small
heating chamber, and upon the inflow of the washer fluid being
stopped, the movable throttle lid descends by its own weight and/or
a spring force, and during the descent, the washer fluid on a lower
side of the movable throttle lid is moved to the upper side of the
movable throttle lid via at least any one of a gap between an inner
face of the small heating chamber and the movable throttle lid, a
gap between an outer face of the electric heater and an inner face
of the central hole of the movable throttle lid, and a void formed
within a face of the movable throttle lid.
5. The washer fluid warming device according to claim 3, wherein
the small heating chamber is formed in a tubular shape extending in
a vertical direction; wherein the washer fluid warming device
further includes a plate-shaped movable throttle lid housed in the
inner space of the small heating chamber; wherein the electric
heater has a stick-like shape and is arranged along a central axis
of the tubular small heating chamber; wherein the movable throttle
lid includes a central hole, and the electric heater is inserted
through the central hole and arranged so that the movable throttle
lid can ascend/descend along the electric heater, and wherein upon
the movable throttle lid being pushed up by the washer fluid
flowing in from a lower portion of the inner space of the small
heating chamber, the movable throttle lid makes the washer fluid on
an upper side of the movable throttle lid flow out of the small
heating chamber, and upon the inflow of the washer fluid being
stopped, the movable throttle lid descends by its own weight and/or
a spring force, and during the descent, the washer fluid on a lower
side of the movable throttle lid is moved to the upper side of the
movable throttle lid via at least any one of a gap between an inner
face of the small heating chamber and the movable throttle lid, a
gap between an outer face of the electric heater and an inner face
of the central hole of the movable throttle lid, and a void formed
within a face of the movable throttle lid.
6. The washer fluid warming device according to claim 4, wherein a
bottom of the tubular small heating chamber is occluded by a plate
material in which a throttle port is formed, through which the
washer fluid in the inner space of the heat-retaining hot fluid
storage chamber flows into the inner space of the small heating
chamber.
7. The washer fluid warming device according to claim 5, wherein a
bottom of the tubular small heating chamber is occluded by a plate
material in which a throttle port is formed, through which the
washer fluid in the inner space of the heat-retaining hot fluid
storage chamber flows into the inner space of the small heating
chamber.
8. The washer fluid warming device according to claim 4, further
comprising a washer fluid flow passage in which the washer fluid
flows into the inner space of the heat-retaining hot fluid storage
chamber from an upper portion of the heat-retaining hot fluid
storage chamber and descends in the inner space of the
heat-retaining hot fluid storage chamber, and the washer fluid that
has descended flows into the inner space of the small heating
chamber from a lower portion of the small heating chamber and
ascends in the inner space of the small heating chamber.
9. The washer fluid warming device according to claim 5, further
comprising a washer fluid flow passage in which the washer fluid
flows into the inner space of the heat-retaining hot fluid storage
chamber from an upper portion of the heat-retaining hot fluid
storage chamber and descends in the inner space of the
heat-retaining hot fluid storage chamber, and the washer fluid that
has descended flows into the inner space of the small heating
chamber from a lower portion of the small heating chamber and
ascends in the inner space of the small heating chamber.
10. The washer fluid warming device according to claim 6, further
comprising a washer fluid flow passage in which the washer fluid
flows into the inner space of the heat-retaining hot fluid storage
chamber from an upper portion of the heat-retaining hot fluid
storage chamber and descends in the inner space of the
heat-retaining hot fluid storage chamber, and the washer fluid that
has descended flows into the inner space of the small heating
chamber from a lower portion of the small heating chamber and
ascends in the inner space of the small heating chamber.
11. The washer fluid warming device according to claim 7, further
comprising a washer fluid flow passage in which the washer fluid
flows into the inner space of the heat-retaining hot fluid storage
chamber from an upper portion of the heat-retaining hot fluid
storage chamber and descends in the inner space of the
heat-retaining hot fluid storage chamber, and the washer fluid that
has descended flows into the inner space of the small heating
chamber from a lower portion of the small heating chamber and
ascends in the inner space of the small heating chamber.
Description
[0001] The disclosure of Japanese Patent Application No.
JP2011-005277 filed on Jan. 13, 2011 including the specification,
drawings, claims and abstract is incorporated herein by reference
in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a device arranged between a
washer tank and a washer nozzle in a washer apparatus on board a
vehicle, the device warming a washer fluid via an electric heater
and being configured so as to be capable of quickly increasing a
temperature of a washer fluid with a relatively-low current,
warming a relatively-large volume of washer fluid, and furthermore,
retaining a washer fluid in a warmed state for some time after a
power supply being turned off, enabling reduction of power required
for increasing the temperature of the washer fluid when the power
supply is turned on next time.
[0004] 2. Description of the Related Art
[0005] For washer fluid warming devices, there have been provided,
e.g., those that use engine waste heat (Japanese Patent Laid-Open
No. 2002-264779), and those that use an electric heater (Japanese
Utility Model Laid-Open No. 6-27391).
[0006] A washer fluid warming device is particularly expected for
use for frost removal in a cold winter; however, those that use
engine waste heat have the problem of requiring long time to warm a
washer fluid from engine starting. Meanwhile, those that use an
electric heater require a large current (40 amperes or more) for
quickly increasing the temperature of a washer fluid, causing
problems such as overusing a battery already weakened by a low
temperature and requiring, e.g., a large relay having thick
electric wires and large contacts as well as transistor devices,
resulting in a cost increase.
[0007] The present invention has been made in view of the
aforementioned points, and an object of the present invention is to
provide a washer fluid warming device capable of quickly increasing
a temperature of a washer fluid with a relatively-low current,
warming a relatively-large volume of washer fluid, and furthermore,
retaining a washer fluid in a warmed state for some time after a
power supply is turned off, enabling reduction of power required
for increasing the temperature of the washer fluid when the power
supply is turned on next time.
SUMMARY OF THE INVENTION
[0008] The present invention provides a washer fluid warming device
arranged between a washer tank and a washer nozzle in a washer
apparatus on board a vehicle, the washer fluid warming device
warming a washer fluid sent in from the washer tank and sending the
washer fluid out to the washer nozzle, the device including: a
heat-retaining hot fluid storage chamber including a wall having a
heat-insulating structure in which a vacuum layer is provided
between an inner wall and an outer wall and including an inner
space into which the washer fluid flowing out of the washer tank
flows as a result of a washer pump being driven; a small heating
chamber including a wall having a thermal conductivity higher than
that of the wall of the heat-retaining hot fluid storage chamber,
being housed in the inner space of the heat-retaining hot fluid
storage chamber, and further including an inner space into which
the washer fluid in the heat-retaining hot fluid storage chamber
flows as a result of the washer pump being driven; and an electric
heater housed in the inner space of the small heating chamber, the
electric heater warming the washer fluid in the small heating
chamber, wherein the inner space of the heat-retaining hot fluid
storage chamber is set to have a size capable of accommodating a
volume of washer fluid that is larger than a volume of washer fluid
that can be accommodated by the inner space of the small heating
chamber; and wherein the warmed washer fluid flowing out of the
small heating chamber is supplied to the washer nozzle as a result
of the washer pump being driven.
[0009] According to the present invention, upon power being
supplied to the electric heater, a washer fluid in the small
heating chamber can be warmed and ejected from the washer nozzle.
The small heating chamber accommodates a volume of washer fluid
that is smaller than a volume of washer fluid that can be
accommodated by the heat-retaining hot fluid storage chamber, and
thus, the temperature of the washer fluid in the small heating
chamber can quickly be increased without using a large current.
When the washer fluid is not ejected, the washer fluid in the
heat-retaining hot fluid storage chamber can be warmed by means of
thermal conduction via the wall of the small heating chamber. Since
the heat-retaining hot fluid storage chamber has a heat-insulating
structure, the washer fluid can be retained in a warmed state for
some time after a power supply is turned off, enabling reduction of
power required for increasing the temperature of the washer fluid
when the power supply is turned on next time.
[0010] In the present invention, it is possible that: the
heat-retaining hot fluid storage chamber includes an opening that
provides communication between an outer space and the inner space
thereof; the small heating chamber with the electric heater housed
therein is attached to a lid that occludes the opening; and the
small heating chamber is inserted into the inner space of the
heat-retaining hot fluid storage chamber from the opening and
thereby housed in the inner space of the heat-retaining hot fluid
storage chamber and the opening is occluded by the lid.
Consequently, a simple configuration can be provided, enabling easy
assembly. Also, it is possible that: the lid includes a washer
fluid inflow channel that allows the washer fluid to flow from the
outside into the heat-retaining hot fluid storage chamber, a washer
fluid outflow channel that allows the washer fluid in the small
heating chamber to flow out to the outside, and an electric wire
leading channel that allows an electric wire for supplying power to
the electric heater to be led to the outside. Consequently, the
necessity for the washer fluid inflow channel, the washer fluid
outflow channel and the electric wire leading channel to be formed
in the heat-retaining hot fluid storage chamber can be eliminated,
providing a simple configuration and thus enabling easy
assembly.
[0011] In the present invention, it is possible that: the small
heating chamber is formed in a tubular shape extending in a
vertical direction; the washer fluid warming device further
includes a plate-shaped movable throttle lid housed in the inner
space of the small heating chamber; the electric heater has a
stick-like shape and is arranged along a central axis of the
tubular small heating chamber; the movable throttle lid includes a
central hole, and the electric heater is inserted through the
central hole and arranged so that the movable throttle lid can
ascend/descend along the electric heater, and upon the movable
throttle lid being pushed up by the washer fluid flowing in from a
lower portion of the inner space of the small heating chamber, the
movable throttle lid makes the washer fluid on an upper side of the
movable throttle lid flow out of the small heating chamber, and
upon the inflow of the washer fluid being stopped, the movable
throttle lid descends by its own weight and/or a spring force, and
during the descent, the washer fluid on a lower side of the movable
throttle lid is moved to the upper side of the movable throttle lid
via at least any one of a gap between an inner face of the small
heating chamber and the movable throttle lid, a gap between an
outer face of the electric heater and an inner face of the central
hole of the movable throttle lid, and a void formed within a face
of the movable throttle lid. Consequently, when a washer fluid is
ejected from the washer nozzle, the washer fluid warmed on the
upper side of the movable throttle lid in the small heating
chamber, which is to be supplied to the washer nozzle, and the
washer fluid flowing in from the lower portion of the small heating
chamber, which is not warmed yet, can be prevented from being
mixed, as a result of the movable throttle lid functioning as a
partition, enabling the warm washer fluid to be ejected from the
washer nozzle.
[0012] In the present invention, it is possible that a bottom of
the tubular small heating chamber is occluded by a plate material
in which a throttle port is formed, through which the washer fluid
in the inner space of the heat-retaining hot fluid storage chamber
flows into the inner space of the small heating chamber.
Consequently, it is possible to prevent a warmed washer fluid in
the small heating chamber from flowing out from the lower portion
of the small heating chamber. Furthermore, in the present
invention, it is possible that the washer fluid warming device
further includes a washer fluid flow passage in which the washer
fluid flows into the inner space of the heat-retaining hot fluid
storage chamber from an upper portion of the heat-retaining hot
fluid storage chamber and descends in the inner space of the
heat-retaining hot fluid storage chamber, and the washer fluid that
has descended flows into the inner space of the small heating
chamber from a lower portion of the small heating chamber and
ascends in the inner space of the small heating chamber.
Consequently, it is possible to provide a favorable flow of a
washer fluid in the warming device. Furthermore, in the present
invention, the heat-retaining hot fluid storage chamber and the
small heating chamber can be formed in, for example, respective
tubular shapes concentric to each other. Consequently, the warming
device can have a compact structure, and thus can be installed in a
narrow space such as an engine room of a vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A and 1B are diagrams illustrating a first embodiment
of a warming device according to the present invention, which are a
transparent front view and a transparent plan view of an inside of
the warming device, respectively;
[0014] FIGS. 2A and 2B are a transparent front view and a
transparent plan view of a heat-retaining hot fluid storage chamber
in the warming device in FIG. 1A, respectively;
[0015] FIGS. 3A and 3B are a transparent front view and a
transparent plan view of a lid of the warming device in FIG. 1A,
respectively;
[0016] FIGS. 4A and 4B are a transparent front view and a
transparent plan view of a sealing rubber (O-ring) to be attached
to the lid in FIG. 3A, respectively;
[0017] FIGS. 5A and 5B are a transparent front view and a
transparent plan view of a small heating chamber in the warming
device in FIG. 1A, respectively;
[0018] FIGS. 6A and 6B are a transparent front view and a
transparent plan view of a lower lid in the warming device in FIG.
1A, respectively;
[0019] FIGS. 7A and 7B are a transparent front view and a
transparent plan view of a movable throttle lid in the warming
device in FIG. 1A, respectively;
[0020] FIG. 8 is a diagram illustrating an electrical system and a
washer fluid feeding system where the warming device in FIG. 1A is
added to an existing washer apparatus;
[0021] FIG. 9 is a schematic diagram illustrating an operation of
the warming device in FIG. 1A;
[0022] FIG. 10 is a table of results of a temperature increase test
using a prototype of the warming device in FIG. 1A, which indicate
changes in temperature of water in the small heating chamber after
start of power supply to the heater;
[0023] FIG. 11 is a table of results of a temperature increase test
using a prototype of the warming device in FIG. 1A, which indicate
changes in temperature increase (increase amount of temperature)
from an initial temperature of water in the heat-retaining hot
fluid storage chamber;
[0024] FIG. 12 is a chart indicating results of a heat-retaining
characteristic test using a prototype of the warming device in FIG.
1A; and
[0025] FIG. 13 is a diagram illustrating a second embodiment of a
warming device according to the present invention, which is a
transparent front view schematically illustrating the inside of the
warming device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0026] A first embodiment of the present invention will be
described. FIGS. 1A and 1B to 7A and 7B are transparent views of
the inside of a warming device 10 according to the present
embodiment. FIGS. 1A and 1B illustrate an assembled state of the
warming device 10, and FIGS. 2A and 2B to 7A and 7B illustrate
respective components of the warming device 10 (the scales of the
diagrams are not the same). The warming device 10 is installed in,
e.g., an engine room of a vehicle in such a manner that the warming
device 10 is stood upright as illustrated in FIG. 1A. In FIG. 1A,
the warming device 10 has a structure in which a cylindrical small
heating chamber 14 is concentrically housed in an inner space 13 of
a cylindrical heat-retaining hot fluid storage chamber 12 and a
round bar-shaped electric heater (hereinafter "heater") 16 is
concentrically housed in an inner space 15 of the small heating
chamber 14. The heater 16 and the small heating chamber 14 are
concentrically attached to a lower face of a lid 30, the small
heating chamber 14 with the heater 16 housed therein is inserted
into the inner space 13 from an upper opening 26 of the
heat-retaining hot fluid storage chamber 12, and the lid 30 is
firmly screwed onto an upper portion of the heat-retaining hot
fluid storage chamber 12, thereby providing an integrated
configuration in their entirety. A washer fluid is fed from a
washer tank 72 (FIG. 8) to the inner space 13 of the heat-retaining
hot fluid storage chamber 12 through a hose 54, and flows into the
inner space 15 of the small heating chamber 14 through throttle
ports 60 at a lower end face of the small heating chamber 14, and
is warmed there by the heater 16. The warmed washer fluid is
supplied to a washer nozzle 80 (FIG. 8) through a hose 56, and
ejected toward a wiping region of, e.g., a front window, a rear
window or wiper-equipped headlamps. A volume of washer fluid that
can be accommodated in the inner space 13 of the heat-retaining hot
fluid storage chamber 12 (i.e., a volume of the inner space 13 of
the heat-retaining hot fluid storage chamber 12 minus a volume of
the small heating chamber 14) is set to be sufficiently larger than
a volume of washer fluid that can be accommodated in the inner
space 15 of the small heating chamber 14 (i.e., a volume of the
inner space 15 of the small heating chamber 14 minus a volume of
the heater 16).
[0027] The heat-retaining hot fluid storage chamber 12 has a
structure similar to that of a vacuum bottle, and as illustrated in
FIGS. 2A and 2B, includes a wall 24 having a heat-insulating
structure in which a vacuum layer 22 is provided between an inner
wall 18 and an outer wall 20. The inner wall 18 is made of, e.g., a
metal such as a stainless steel or glass with a vacuum layer
22-side face plated with metal. The outer wall 20 is made of, e.g.,
a metal such as a stainless steel. A lower end of the
heat-retaining hot fluid storage chamber 12 is closed, and the
opening 26 is formed at an upper end of the heat-retaining hot
fluid storage chamber 12. At an outer periphery of a wall 28
forming the peripheral opening 26, a thread 32 onto which the lid
30 is screwed is provided.
[0028] The opening 26 of the heat-retaining hot fluid storage
chamber 12 is closed by the lid 30. The lid 30 is made of, e.g., a
resin, and as illustrated in FIG. 3A, includes a core 33 and an
outer peripheral wall 34 surrounding the core 33 on the lower face
side thereof. A groove 36, which opens downward, is formed between
the core 33 and the outer peripheral wall 34. An inner periphery of
the outer peripheral wall 34 is provided with a thread 38. A
sealing rubber (O-ring) 40, which is illustrated in FIGS. 4A and
4B, is accommodated in the groove 36. The sealing rubber 40 is
accommodated in the groove 36, the wall 28 of the opening 26 of the
heat-retaining hot fluid storage chamber 12 is inserted into the
groove 36, and the lid 30 is rotated to screw and firmly fasten the
threads 32 and 38 together, whereby the opening 26 of the
heat-retaining hot fluid storage chamber 12 is sealed with the lid
30. In such state, the core 33 is inserted in the opening 26.
[0029] An electric wire leading channel 44 (FIGS. 3A and 3B) for
leading an electric wire 42 (FIGS. 1A and 1B), which supplies power
to the heater 16, to the outside is provided on a central axis of
the core 33 of the lid 30. The electric wire leading channel 44 can
be used for leading a lead wire (not illustrated) for a temperature
sensor (not illustrated) for detecting a temperature of the washer
fluid in the inner space 15 of the small heating chamber 14 to the
outside. Furthermore, the core 33 has a washer fluid inflow channel
46 that allows the washer fluid to flow into the heat-retaining hot
fluid storage chamber 12 from the outside, and a washer fluid
outflow channel 48 that allows the washer fluid in the small
heating chamber 14 to flow out to the outside. The washer fluid
outflow channel 48 opens upward in the small heating chamber 14,
and thus, even if there is no longer washer fluid in the washer
tank 72 (FIG. 8), the small heating chamber 14 is prevented from
becoming empty inside, enabling the heater 16 to be prevented from
heating the small heating chamber 14 in an empty state. At an upper
face of the lid 30, hose connection ports 50 and 52, which
communicate with the washer fluid inflow channel 46 and the washer
fluid outflow channel 48, respectively, are protrudingly formed.
The hoses 54 and 56 (FIG. 1A) are inserted into and thereby
connected to the hose connection ports 50 and 52.
[0030] The round bar-shaped heater 16 (FIGS. 1A and 1B) is secured
to a lower face of the lid 30 on a central axis of the lid 30. The
heater 16 includes, e.g., an electrical heating wire-used heater or
a PTC ceramic heater enclosed in a cylindrical casing such as a
metal pipe or a ceramic pipe. Use of what is called an auto heater
with a temperature sensor included therein, which has a temperature
control function, as the heater 16 eliminates the need to
separately install a temperature sensor in the small heating
chamber 14. The small heating chamber 14 is secured to the lower
face of the lid 30 in a state in which the heater 16 is housed in
the inner space 15 thereof. As illustrated in FIGS. 5A and 5B, the
small heating chamber 14 includes a cylindrical member. The small
heating chamber 14 has a moderate thermal conductivity, and has a
non-heat-insulating structure (a structure including no vacuum
layer) made of a material such as a resin, e.g., a hard vinyl
chloride resin, ceramics or a metal. An upper end 14a of the small
heating chamber 14 is occluded by the lower face of the lid 30, and
a lower end 14b thereof is bonded to and thereby occluded by a
discoid lower lid 58 (plate material in which throttle port(s)
is(are) formed), which is illustrated in FIGS. 6A and 6B. The lower
lid 58 can be made of a material similar to that of the small
heating chamber 14 (e.g., a resin, ceramic or a metal). A plurality
of throttle ports 60 is formed in the lower lid 58. The washer
fluid in the inner space 13 of the heat-retaining hot fluid storage
chamber 12 flows into the inner space 15 of the small heating
chamber 14 through the throttle ports 60.
[0031] A discoid movable throttle lid 61 is housed in the inner
space 15 of the small heating chamber 14. The movable throttle lid
61 is made of a material, such as a hard vinyl chloride resin,
having a specific gravity that is somewhat larger than that of the
washer fluid. As illustrated in FIGS. 7A and 7B, the movable
throttle lid 61 has a discoid shape, and includes a circular
central hole 62 formed at a center thereof. The movable throttle
lid 61 has an outer diameter that is somewhat smaller than an inner
diameter of the small heating chamber 14, and the central hole 62
has an inner diameter that is somewhat larger than an outer
diameter of the heater 16. The movable throttle lid 61 is housed in
the inner space 15 of the small heating chamber 14 as a result of
the heater 16 being inserted into the central hole 62, and is
thereby arranged so that the movable throttle lid 61 can freely
ascend/descend along the heater 16.
[0032] FIG. 8 illustrates an electrical system and a washer fluid
feeding system where the warming device 10 with the above-described
configuration is added to an existing washer apparatus. FIG. 8
illustrates a case where temperature control is performed using a
mechanical sensing-type temperature sensor including a bimetal or a
shape-memory alloy, which is installed, e.g., inside the small
heating chamber 14 of the warming device 10. The part surrounded by
a dotted line is a part added to an existing washer apparatus in
order to use the warming device 10. The heater 16 and a washer
motor 76 are driven using a battery 63 as a power supply. In other
words, the heater 16 and the mechanical sensing-type temperature
sensor 64 are serially connected to the battery 63 via an ignition
switch 66 and a relay switch 68. The mechanical sensing-type
temperature sensor 64 includes a switch (mechanical thermostat)
including a moving contact made of, e.g., a bimetal or a
shape-memory alloy, and turns the switch on when a temperature of
the washer fluid in the small heating chamber 14 is equal to or
lower than a set temperature (for example, 60 deg C.), and turns
the switch off when the temperature exceeds the set temperature. A
timer circuit 70 is provided to turn the relay switch 68 on/off,
and in order to suppress power consumption when ignition is started
(i.e., when a cell motor is driven), the relay switch 68 is kept in
an off state until a predetermined period of time (for example,
several seconds) elapses from the ignition switch 66 being turned
on, and after the elapse of the predetermined period of time, the
relay switch 68 is kept in an on state until the ignition switch 66
is turned off. The washer tank 72 is charged with a washer fluid.
Upon a washer switch 74 being turned on via an operation by, e.g.,
a driver, power is supplied to the washer motor 76, and
consequently, the washer pump 78 is driven, whereby the washer
fluid in the washer tank 72 is supplied to the warming device 10
through the hose 54. The washer fluid warmed in the warming device
10 is supplied to the washer nozzle 80 through the hose 56 and
ejected.
[0033] FIG. 9 illustrates an operation of the warming device 10.
Respective steps (1) to (4) will be described.
(1) A state in which the washer switch 74 (FIG. 8) is on is
illustrated. A washer fluid 82 fed from the washer tank 72 is
injected to an upper space inside the heat-retaining hot fluid
storage chamber 12 via the hose 54. Consequently, the washer fluid
82 in the heat-retaining hot fluid storage chamber 12 descends and
flows into the small heating chamber 14 from the throttle ports 60
of the lower lid 58. Here, the movable throttle lid 61 in the small
heating chamber 14 is pushed up by the inflowing washer fluid 82.
Consequently, the warmed washer fluid 82 on the upper side of the
movable throttle lid 61 is discharged from the warming device 10
via the hose 56 and ejected from the washer nozzle 80. (2) Upon the
washer switch 74 being turned off, the supply of the washer fluid
82 from the washer tank 72 is stopped. Consequently, the movable
throttle lid 61 descends by means of its own weight. Here, the
washer fluid 82 on the lower side of the movable throttle lid 61
moves to the upper side of the movable throttle lid 61 via a gap 84
between an outer periphery of the movable throttle lid 61 and an
inner periphery of the small heating chamber 14. (3) Since the
power supply to the heater 16 is continued, the washer fluid 82 in
the small heating chamber 14 is warmed. Since the small heating
chamber 14 has a small volumetric capacity, even if an output of
the heater 16 is relatively small (that is, a relatively small
current of, for example, around five amperes), a temperature of the
washer fluid 82 in the small heating chamber 14 can quickly be
increased. Furthermore, here, the movable throttle lid 61 occludes
the throttle ports 60 of the lower lid 58 as a result of landing on
the lower lid 58, enabling the warmed washer fluid 82 in the small
heating chamber 14 to be prevented from flowing out to the inner
space 13 of the heat-retaining hot fluid storage chamber 12 through
the throttle ports 60. Upon the washer fluid 82 in the small
heating chamber 14 being warmed and the washer switch 74 being
turned on again, the warmed washer fluid 82 is supplied to the
washer nozzle 80 through the hose 56 and ejected again through step
(1) above. (4) If the washer switch 74 is left off in step (3)
above, heat of the washer fluid 82 in the small heating chamber 14
is conducted to the washer fluid 82 in the heat-retaining hot fluid
storage chamber 12 by means of thermal conduction via a wall of the
small heating chamber 14, whereby the washer fluid 82 in the
heat-retaining hot fluid storage chamber 12 is warmed. When the
temperature of the washer fluid 82 in the small heating chamber 14
exceeds a set temperature (for example, 60 deg C.) of the
mechanical sensing-type temperature sensor 64 (FIG. 8), the
mechanical sensing-type temperature sensor 64 is turned off,
whereby the power supply to the heater 16 is stopped. Since the
heat-retaining hot fluid storage chamber 12 has the heat-insulating
structure, the heat of the washer fluid 82 in the warming device 10
is retained even though the power supply to the heater 16 is
stopped. If the temperature of the washer fluid 82 in the small
heating chamber 14 is decreased to be equal to or lower than a
predetermined value, the power supply to the heater 16 is resumed,
and thereafter, the power supply to the heater 16 is repeatedly
started and stopped until the ignition switch 66 is turned off.
When the ignition switch 66 is turned off, the power supply to the
heater 16 is also stopped; however, the heat-retaining hot fluid
storage chamber 12 has the heat-insulating structure, and thus, the
heat of the washer fluid 82 in the warming device 10 is retained
for a long time.
Experimental Example
[0034] A prototype of the warming device 10 is fabricated, and a
temperature increase characteristic of water when the small heating
chamber 14 and the heat-retaining hot fluid storage chamber 12 are
filled with the water and power is continuously supplied to the
heater 16, and a temperature decrease characteristic
(heat-retaining characteristic) of the water in the warming device
10 after the power supply to the heater 16 is stopped were
measured. The prototype of the warming device 10 was fabricated
using the following parts.
[0035] Heat-retaining hot fluid storage chamber 12: a body of a
commercially-available vacuum water bottle was used as it is.
[0036] Lid 30: a lid of the vacuum water bottle used for the
heat-retaining hot fluid storage chamber 12 was modified and
used.
[0037] Small heating chamber 14: a hard vinyl chloride resin
tube
[0038] Lower lid 58: a hard vinyl chloride resin plate
[0039] Movable throttle lid 61: a hard vinyl chloride resin
plate
[0040] Heater 16: electrical heating wire-used heater (output of 60
watts)
[0041] A total amount of the water in the warming device 10 (a sum
of amounts of water charged in the small heating chamber 14 and the
heat-retaining hot fluid storage chamber 12) was 485 ml, and the
small heating chamber 14 has a volumetric capacity of 50 ml. An
initial temperature of the water in a temperature increase test
(FIGS. 10 and 11) was 14 deg C., and an initial temperature of the
water in a heat-retaining characteristic test (FIG. 12) was 60 deg
C.
[0042] FIG. 10 illustrates changes in temperature of the water in
the small heating chamber 14 after the power supply to the heater
16 is started. The table indicates that the temperature of the
water reached 85 deg C. or higher approximately five minutes after
the start of the power supply. FIG. 11 illustrates changes in
temperature increase (increase amount of temperature) of the water
in the heat-retaining hot fluid storage chamber 12 (temperature
increase from the initial temperature of 14 deg C.). The table
indicates that a temperature increase of 70 deg C. or higher
occurred 40 minutes after the start of the power supply.
[0043] FIG. 12 illustrates changes in temperature of the water in
the warming device 10 when the power supply to the heater 16 was
left stopped after the temperature of the water in the warming
device 10 being made to 60 deg C. Measurements were made for
respective cases where an external air temperature was -5 deg C.,
-10 deg C., -15 deg C., -20 deg C., -25 deg C. and -30 deg C. The
table indicates that the temperature of the water after the elapse
of about thirteen hours were 27 deg C. for the case where the
external air temperature was -5 deg C., and 13 deg C. for the case
where the external air temperature was -30 deg C. Accordingly, for
example, where a driver starts his/her car up in the morning
following a night when he/she returned home by the car, the
temperature of the water can still be kept warm, enabling
suppression of time and power required for temperature increase at
the time of start-up.
Second Embodiment
[0044] A second embodiment of the present invention will be
described. FIG. 13 is a transparent view schematically illustrating
a warming device 86 according to the present embodiment. In the
warming device 86, a lid 30 with a small heating chamber 14 and a
heater 16 attached thereto is arranged on the lower side thereof to
enhance the heat-insulating properties of an upper portion of the
warming device 86 in which a washer fluid having a high temperature
is accumulated and suppress heat loss from the upper portion,
thereby providing further enhancement of the heat-retaining
performance. Components that are in common to those of the first
embodiment are provided with reference numerals that are the same
as those of the first embodiment. The warming device 86 is
installed in, e.g., an engine room of a vehicle in such a manner
that the warming device 86 is stood upright as illustrated in FIG.
13. The warming device 86 has a structure in which a cylindrical
small heating chamber 14 having a moderate thermal conductivity is
concentrically housed in an inner space 13 of a cylindrical
heat-retaining hot fluid storage chamber 12 having a
heat-insulating structure and a round bar-shaped heater 16 is
concentrically housed in an inner space 15 of a small heating
chamber 14. The heater 16 and the small heating chamber 14 are
attached to a upper face of the lid 30, the heater 16 and the small
heating chamber 14 are inserted into the inner space 13 from a
lower opening 26 of the heat-retaining hot fluid storage chamber
12, and the lid 30 is firmly screwed to a lower portion of the
heat-retaining hot fluid storage chamber 12, thereby providing an
integrated configuration in their entirety. A washer fluid is fed
from a washer tank 72 (FIG. 8) to the inner space 13 of the
heat-retaining hot fluid storage chamber 12 through a hose 54, and
flows into the inner space 15 of the small heating chamber 14
through throttle ports 60 at a lower end face of the small heating
chamber 14, and is warmed there by the heater 16. The warmed washer
fluid is sent out to a washer nozzle 80 (FIG. 8) through a hose 56,
and ejected toward a wiping region of, e.g., a front window, a rear
window or a wiper-equipped headlamp. A volume of washer fluid that
can be accommodated in the inner space 13 of the heat-retaining hot
fluid storage chamber 12 (i.e., a volume of the inner space 13 of
the heat-retaining hot fluid storage chamber 12 minus a volume of
the small heating chamber 14) is set to be sufficiently larger than
a volume of washer fluid that can be accommodated in the inner
space 15 of the small heating chamber 14 (a volume of the inner
space 15 of the small heating chamber 14 minus a volume of the
heater 16).
[0045] An electric wire 42 for supplying power to the heater 16, an
inflow pipe (washer fluid inflow channel) 88 for injecting the
washer fluid to an upper portion of the inner space 13 of the
heat-retaining hot fluid storage chamber 12, and an outflow pipe
(washer fluid outflow channel) 90 that allows the warmed washer
fluid in an upper portion of the inner space 15 of the small
heating chamber 14 to flow out to the outside penetrate the lid 30
and are attached to the lid 30 in a watertight state. A temperature
sensor 92 is provided inside the inner space 15 of the small
heating chamber 14. A lead wire 94 for the temperature sensor 92
watertightly penetrates the lid 30 and is led to the outside.
Instead of providing the temperature sensor 92 independently, what
is called an auto heater including a temperature sensor therein and
having a temperature control function can be used as the heater
16.
[0046] As with the warming device 10 according to the first
embodiment, the warming device 86 can be included in the electrical
system and the washer fluid feeding system in FIG. 8 and can be
used so as to operate as illustrated in FIG. 9. In other words,
upon power being supplied to the heater 16, the washer fluid in the
small heating chamber 14 is warmed, and heat of the washer fluid is
conducted to the washer fluid in the heat-retaining hot fluid
storage chamber 12 by means of thermal conduction via a wall of the
small heating chamber 14, and the washer fluid in the
heat-retaining hot fluid storage chamber 12 is thereby warmed. Upon
a washer switch 74 (FIG. 8) being turned on, the washer fluid fed
from the washer tank 72 (FIG. 8) is supplied to the upper portion
of the inner space 13 of the heat-retaining hot fluid storage
chamber 12 through the inflow pipe 88, and descends in the inner
space 13 and flows into the small heating chamber 14 from the
throttle ports 60 of the lower lid 58. Here, a movable throttle lid
61 in the small heating chamber 14 is pushed up by the inflowing
washer fluid. Consequently, the warmed washer fluid on the upper
side of the movable throttle lid 61 flows through the outflow pipe
90 from the upper portion of the small heating chamber 14 and is
discharged out of the warming device 86 and ejected from the washer
nozzle 80 (FIG. 8). The outflow pipe 90, which corresponds to the
washer fluid outflow channel, opens upward in the small heating
chamber 14, and thus, even if there is no longer washer fluid in
the washer tank 72 (FIG. 8), the small heating chamber 14 is
prevented from being empty inside, enabling the heater 16 to be
prevented from heating the small heating chamber 14 in an empty
state. The rest of operation is the same as that of the first
embodiment.
[0047] Although in the first and second embodiments, the movable
throttle lid 61 descends by means of its own weight, as illustrated
in an alternate long and two short dashes line in FIGS. 1A and 13,
a weak spring 96 is fitted on the heater 16 to exert a biasing
force (extending force) of the spring 96 on the movable throttle
lid 61, enabling the movable throttle lid 61 to descend by means of
the extending force of the spring 96 (or a combined force of the
extending force of the spring 96 and the weight of the movable
throttle lid 61). Also, although in the first and second
embodiments, the washer fluid moves from the lower side to the
upper side of the movable throttle lid 61 through the gap 84
between the outer periphery of the movable throttle lid 61 and the
inner periphery of the small heating chamber 14 when the movable
throttle lid 61 descends, such movement may be made through a gap
between the outer periphery of the heater 16 and the central hole
62 of the movable throttle lid 61, or a void separately provided
within a face of the movable throttle lid 61, such as a valved hole
(the valve is arranged so as to be closed when the movable throttle
lid 61 ascends and be opened when the movable throttle lid 61
descends) or a cutout. Furthermore, in the first and second
embodiments, a water level sensor can be arranged inside the small
heating chamber 14 to supply power to the heater 16 based on the
condition that a water level inside the small heating chamber 14 is
equal to or exceeds a predetermined value. Furthermore, although in
the first and second embodiments, as illustrated in FIG. 8, the
existing washer pump 78 that comes with the washer tank 72 is used
to feed a washer fluid, if the flow passage has a larger resistance
as a result of addition of the warming device, resulting in a
washer fluid being not ejected from the washer nozzle 80 with a
sufficient force, a washer pump may be added to the warming device
to feed a washer fluid by means of, e.g., serial driving of the two
washer pumps.
* * * * *