U.S. patent application number 10/759843 was filed with the patent office on 2004-12-23 for resin tank.
Invention is credited to Suenaga, Makoto.
Application Number | 20040256396 10/759843 |
Document ID | / |
Family ID | 32588597 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040256396 |
Kind Code |
A1 |
Suenaga, Makoto |
December 23, 2004 |
Resin tank
Abstract
A resin tank includes a tank body, a pipe sealing member and a
pipe. The tank body reserves a liquid and is made of resin. Also,
the tank body has at least a circular hole that connects with an
inside of the tank body. The pipe sealing member is closely fitted
into the circular hole. The pipe is installed in the pipe sealing
member.
Inventors: |
Suenaga, Makoto;
(Kariya-shi, JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
345 Park Avenue
New York
NY
10154
US
|
Family ID: |
32588597 |
Appl. No.: |
10/759843 |
Filed: |
January 16, 2004 |
Current U.S.
Class: |
220/565 |
Current CPC
Class: |
B60K 15/03177 20130101;
F15B 1/26 20130101; F15B 21/045 20130101 |
Class at
Publication: |
220/565 |
International
Class: |
B65D 090/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 20, 2003 |
JP |
P2003-011417 |
Claims
What is claimed is:
1. A resin tank comprising: a tank body for reserving a liquid, the
tank body being made of resin, the tank body having at least a
circular hole that connects with an inside of the tank body; a pipe
sealing member closely fitted into the circular hole; and a pipe
installed in the pipe sealing member.
2. The resin tank according to claim 1, wherein the pipe is
detachable from the pipe sealing member.
3. The resin tank according to claim 1, wherein the pipe is
integrally molded with the pipe sealing member.
4. The resin tank according to claim 1, wherein the pipe sealing
member has at least a pipe fitting hole.
5. The resin tank according to claim 4, wherein the number of the
pipe fitting holes is plural.
6. The resin tank according to claim 1, wherein the pipe sealing
member is made of elastic material and has a closely fitting
portion that is closely fitted into the circular hole, the closely
fitting portion and the pipe fitting hole having a concentric
circle with each other.
7. The resin tank according to claim 1, wherein the resin tank is
an oil tank for use in a loading apparatus of an industrial
vehicle.
8. The resin tank according to claim 1, wherein the pipe is made of
metallic material.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a resin tank that reserves
a liquid and more particularly to the resin tank having a pipe that
circulates the liquid.
[0002] Conventionally, a tank made of resin material, such as a
synthetic resin, is widely known as a tank that reserves a liquid
such as oil. Japanese Unexamined Patent Publication No. 2002-195202
discloses this type of resin tank, which has a pipe to circulate
the liquid. (See the drawings 1 though 3 and 16 through 20 of the
above reference)
[0003] Now, referring to FIG. 7, a prior art resin tank 40 includes
a tank body 41, which is made of synthetic resin, a plurality of
pipes 43a, 43b, 43c and 43d, and a plate-like cover 44. An opening
42 is formed in the tank body 41, to which the cover 44 is fixed so
as to cover the opening 42. The pipes 43a, 43b, 43c and 43dare
installed in the cover 44.
[0004] The pipes 43a, 43b, 43c and 43d are fixed to the cover 44 by
welding. The pipes 43a, 43b, 43c and 43d, and the cover 44 are made
of metallic material.
[0005] In the resin tank 40, a gasket 45 is interposed between the
tank body 41 and the cover 44 in order to enhance sealing
performance of an interface between the tank body 41 and the cover
44. In addition, a plurality of bolts 46 fixes the cover 44 on the
tank body 41.
[0006] Therefore, a plurality of bolt holes 44a is formed in the
cover 44 and a plurality of bolt holes 45a is formed in the gasket
45. Meanwhile, a plurality of nuts 47 is embedded near a marginal
portion of the opening 42 of the tank body 41 so as to correspond
to the bolts 46.
[0007] Meanwhile, referring to FIG. 8, a prior art resin tank 50
includes a tank body 51 and a frame-like bracket 53 made of
metallic material. An opening 52 is formed in the tank body 51. The
bracket 53, in which a plurality of tapped holes 53a is bored, is
embedded near the opening 52 of the tank body 51 in place of the
nuts 47, which are embedded in the tank body 41 of the resin tank
40 as described above. The gasket 45 and the cover 44 of the resin
tank 50 are the same as those of the resin tank 40, which is shown
in FIG. 7. In FIGS. 7 and 8, a part of reference numerals are used
in common.
[0008] Such a resin tank 40 enhances sealing performance between
the tank body 41 and the cover 44. Also, the resin tank 50 enhances
sealing performance between the tank body 51 and the cover 44.
Thereby, hydraulic leakage is prevented.
[0009] However, there is a fear of hydraulic leakage in the
above-mentioned resin tanks 40 and 50. In addition, a large number
of parts increase manufacturing cost. Further, assembling the resin
tanks 40 and 50 becomes extremely complicated because of a large
number of parts.
[0010] Specifically, referring to FIG. 7, in the resin tank 40, the
nuts 47, which are embedded in the tank body 41, are attracted to
the cover 44 by axial force caused by tightening the bolts 46.
Thereby, the tank body 41 and the gasket 45 are bent. Consequently,
the sealing performance between the cover 44 and the tank body 41
deteriorates.
[0011] In particular, when a hydraulic fluid for use in driving a
loading apparatus of an industrial vehicle is handled, the
temperature of the liquid rises to about 80 through about
100.degree. C. In this case, the deformation of the tank body 41
and the gasket 45, which is caused by the axial force of the bolts
46, becomes remarkable.
[0012] Further, the resin tank 40 requires a large number of bolts
46 and a large number of nuts 47 in order to ensure the sealing
performance between the tank body 41 and the cover 44.
Consequently, a large number of parts increase manufacturing cost.
Further, assembling the resin tank 40 requires a complicated
operation because of a large number of parts.
[0013] Meanwhile, referring to FIG. 8, the resin tank 50 requires
uniformly tightening the bolts 46 to the frame-like bracket 53.
Otherwise, the location of the bracket 53 relative to the tank body
51 is slanted. Thereby, the tank body 51 is deformed.
[0014] Also, when a hydraulic fluid, which is a high-temperature
liquid, for use in driving the loading apparatus of the industrial
vehicle is handled, there is a fear of the deformation and the
crack of the tank body 51 since the coefficient of thermal
expansion of the tank body 51 made of resin material is different
from that of the frame-like bracket 53 made of metallic
material.
[0015] Further, the resin tank 50 still requires the bolts 46 while
eliminating the nuts 47 from the resin tank 40. Also, a plurality
of tapped holes 53a requires machining in the frame-like bracket
53. Thereby, the effect of the elimination of the nuts 47 is
cancelled by machining the frame-like bracket 53. Consequently, the
manufacturing cost of the resin tank 50 is not sufficiently
reduced.
[0016] In addition, assembling the resin tank 50 requires a
complicated operation similarly to assembling the resin tank
40.
SUMMARY OF THE INVENTION
[0017] The present invention is directed to a resin tank that
reliably prevents leakage of a liquid, which is caused by
deformation of the tank body, and that is simply assembled while
reducing manufacturing cost by reducing the number of parts of the
resin tank and machining of the parts to a minimum.
[0018] The present invention has a following feature. A resin tank
includes a tank body, a pipe sealing member and a pipe. The tank
body reserves a liquid and is made of resin. Also, the tank body
has at least a circular hole that connects with an inside of the
tank body. The pipe sealing member is closely fitted into the
circular hole. The pipe is installed in the pipe sealing
member.
[0019] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The features of the present invention that are believed to
be novel are set forth with particularity in the appended claims.
The invention, together with objects and advantages thereof, may
best be understood by reference to the following description of the
presently preferred embodiments together with the accompanying
drawings in which:
[0021] FIG. 1 is a perspective view illustrating a resin tank
according to a first preferred embodiment of the present
invention;
[0022] FIG. 2 is a perspective view illustrating a first pipe
sealing member according to the first preferred embodiment of the
present invention;
[0023] FIG. 3 is a partial cross-sectional view illustrating a
relation between a tank body and the first pipe sealing member
according to the first preferred embodiment of the present
invention;
[0024] FIG. 4 is a partially cutaway view taken along the line A-A
of FIG. 3;
[0025] FIG. 5 is a perspective view illustrating a second pipe
sealing member according to the first preferred embodiment of the
present invention;
[0026] FIG. 6A is a partial cross-sectional view illustrating a
relation between a tank body and a third pipe sealing member
according to a second preferred embodiment of the present
invention;
[0027] FIG. 6B is an enlarged top view illustrating a third pipe
sealing member according to the second preferred embodiment of the
present invention;
[0028] FIG. 7 is a perspective view illustrating a prior art resin
tank; and
[0029] FIG. 8 is a partial side view illustrating another prior art
resin tank.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] A tank 10 according to a first preferred embodiment of the
present invention will now be described with reference to FIGS. 1
through 3. The tank 10 is made of resin and is hereinafter referred
to a resin tank 10.
[0031] In the present embodiment, the resin tank 10 is an oil tank
that is installed in a forklift truck serving as an industrial
vehicle. The oil tank constitutes a part of a hydraulic circuit of
a loading apparatus.
[0032] As shown in FIG. 1, the resin tank 10 mainly includes a tank
body 11, a pipe sealing member 12, a pipe sealing member 13, a pipe
14 and a pipe 15.
[0033] First of all, the tank body 11 is described. The tank body
11 is structured so as to reserve hydraulic fluid inside thereof.
Also, the tank body 11 is made of synthetic resin that has
elasticity and thereby its weight is reduced.
[0034] Referring to FIG. 1, a tubular inlet 16 and a tubular outlet
17 are installed on one side face of the tank body 11. The
hydraulic fluid is returned from the hydraulic circuit, which is
not shown in FIG. 1, to the tank body 11 through the inlet 16.
Also, the hydraulic fluid is sent from the tank body 11 to an oil
pump, which is not shown in FIG. 1, through the outlet 17.
[0035] The inlet 16 and the outlet 17 are integrally molded with
the tank body 11. A hose or a pipe is connected to the inlet 16 and
the outlet 17.
[0036] Meanwhile, many curved surfaces are used for the tank body
11. Thereby, the strength of the tank body 11 is improved and the
space of the tank body 11 is effectively used.
[0037] Incidentally, the temperature of the hydraulic fluid, which
is used in the forklift truck, rises to 80 through 100.degree. C.
In addition, as the temperature of the hydraulic fluid rises and
falls, the temperature of the tank body 11 also rises and falls.
Therefore, thermal stress is caused to the tank body 11. However,
the structure of the tank body 11, which has many curved surfaces,
prevents an excessive deformation and a crack of the tank body 11
caused by the thermal stress.
[0038] In the present embodiment, a part of the top face of the
tank body 11 is elevated to form a protuberance 18. A first
circular hole 19 and a second circular hole 20 are formed in the
top face of the protuberance 18, and each connects with the inside
of the tank body 11.
[0039] The first circular hole 19 enables the pipe 14 to connect
with the tank body 11 through the pipe sealing member 12, which is
described later. Also, the second circular hole 20 enables the pipe
15 to connect with the tank body 11 through the pipe sealing member
13, which is described later.
[0040] The diameter of the first circular hole 19 is larger than
that of the second circular hole 20. The pipe 14 is hereinafter
referred to a first pipe 14 and is used for lubrication and
identification of oil level. Also, the pipe 15 is hereinafter
referred to a second pipe 15 and is used when the tank body 11
recovers the hydraulic fluid that overflows in a hydraulic device
such as a lift cylinder.
[0041] The first circular hole 19 is further described. As shown in
FIGS. 1 through 3, a first stepped portion 21 is annularly formed
on the circumference of the first circular hole 19 so as to locate
at a lower level than the surface of the protuberance 18. Also, the
first stepped portion 21 has the same thickness as the tank body
11.
[0042] Therefore, it is mentioned that a marginal portion S1 of the
first circular hole 19 is formed by the first stepped portion 21.
Note that the marginal portion S1 of the first circular hole 19 is
a portion that closely fits to the pipe sealing member 12, which is
described later.
[0043] The tank body 11 is stepped in such a manner that the first
stepped portion 21, which forms the first circular hole 19, has the
same thickness as the tank body 11. Thereby, it is considered that
the rigidity of the tank body 11 near the first circular hole 19 is
enhanced.
[0044] Also, a second stepped portion 22 is annularly formed on the
circumference of the second circular hole 20 so as to locate at a
lower level than the surface of the protuberance 18. The second
stepped portion 22 also has the same thickness as the tank body
11.
[0045] The first circular hole 19 has a circular shape. The
circular shape of the first circular hole 19 enables the pipe
sealing member 12 to supply the marginal portion S1 of the first
circular hole 19 with uniform contact pressure when the pipe
sealing member 12, which is described later, is closely fitted into
the first circular hole 19. Thus, the circular shape of the first
circular hole 19 is the most suitable shape. Also, the second
circular hole 20 has a circular shape. The circular shape of the
second circular hole 20 enables the pipe sealing member 13 to
supply the marginal portion S2 of the second circular hole 20 with
uniform contact pressure when the pipe sealing member 13, which is
described later, is closely fitted into the second circular hole
20. Thus, the circular shape of the second circular hole 20 is the
most suitable shape.
[0046] Now, the pipe sealing members 12 and 13 are described. In
the present embodiment, as described above, the resin tank 10
includes the pipe sealing member 12 and the pipe sealing member 13.
The pipe sealing member 12 is hereinafter referred to a first pipe
sealing member 12 and the pipe sealing member 13 is hereinafter
referred to a second pipe sealing member 13.
[0047] The first pipe sealing member 12 includes the first pipe 14
and is closely fitted into the first circular hole 19 of the tank
body 11. Thereby, the first pipe 14 is connected to the tank body
11.
[0048] Also, the second pipe sealing member 13 includes the second
pipe 15 and is closely fitted into the second circular hole 20 of
the tank body 11. Thereby, the second pipe 15 is connected to the
tank body 11.
[0049] Now, the first pipe sealing member 12 is described in
detail. The first pipe sealing member 12 is obtained by integrally
molding elastic material such as an oil-resisting rubber. As shown
in FIGS. 2 and 3, the first pipe sealing member 12 basically
includes a flange 12a, a retaining portion 12b, a closely fitting
portion 12c, a tapered collar 12d, a pipe fitting hole 12e, a
tapered surface 12f and a collared surface 12g.
[0050] Since the first pipe sealing member 12 has the pipe fitting
hole 12e, the first pipe 14 is attached to or detached from the
first pipe sealing member 12.
[0051] The flange 12a, which has the largest diameter among the
diameters of the first pipe sealing member 12, is contacted with
the first stepped portion 21 of the tank body 11 and a part of the
surface of the tank body 11.
[0052] The retaining portion 12b is formed on the top face of the
flange 12a and has a tapered surface. As shown in FIG. 3, in the
first pipe sealing member 12, the pipe fitting hole 12e extends
from the top face of the retaining portion 12b to the bottom face
of the tapered collar 12d.
[0053] Therefore, when the first pipe 14 is installed in the first
pipe sealing member 12, the retaining portion 12b regulates the
tilt of the first pipe 14 relative to the first pipe sealing member
12.
[0054] Also, the closely fitting portion 12c is formed on the
bottom face of the flange 12a and is closely fitted into the first
circular hole 19 of the tank body 11. In other words, the first
pipe sealing member 12 has the closely fitting portion 12c, which
is closely fitted into the first circular hole 19.
[0055] While the diameter of the closely fitting portion 12c is
slightly larger than that of the first circular hole 19 of the tank
body 11, since in the present embodiment, the first pipe sealing
member 12 is made of elastic material, the closely fitting portion
12c is simply fitted into the first circular hole 19. Thereby, the
closely fitting portion 12c is closely contacted with the first
circular hole 19 by elastic force of the first pipe sealing member
12.
[0056] In addition, the tapered collar 12d is formed underneath the
closely fitting portion 12c. As shown in FIG. 3, the tapered
surface 12f is formed on the tapered collar 12d in such a manner
that the diameter of the first pipe sealing member 12 reduces from
the closely fitting portion side to the bottom face of the first
pipe sealing member 12. Thereby, the tapered surface 12f enables
the first pipe sealing member 12 to be easily fitted into the first
circular hole 19.
[0057] Further, the collared surface 12g is formed on the closely
fitting portion side of the tapered collar 12d and thereby prevents
the first pipe sealing member 12 from slipping from the first
circular hole 19 when the first pipe sealing member 12 is fitted
into the first circular hole 19 so as to be closely contacted with
each other.
[0058] Incidentally, although the pipe fitting hole 12e extends
through the first pipe sealing member 12 as mentioned above, in the
present embodiment, as shown in FIG. 4, every inner surface of the
first pipe sealing member 12 that forms the pipe fitting hole 12e
is contacted with a part of the outer surface of the first pipe
14.
[0059] Although the inside diameter of the pipe fitting hole 12e is
set to be slightly smaller than the outside diameter of the first
pipe 14, the first pipe sealing member 12, which is made of elastic
member, enables the first pipe 14 to be fitted into the pipe
fitting hole 12e. In addition, the first pipe 14 is reliably
closely contacted with the pipe fitting hole 12e by the elastic
force of the first pipe sealing member 12.
[0060] Also, in the present embodiment, the pipe fitting hole 12e
extends though the middle of the first pipe sealing member 12. The
pipe fitting hole 12e, the flange 12a, the retaining portion 12b,
the closely fitting portion 12c and the tapered collar 12d have a
concentric circle with each other.
[0061] Especially, since the closely fitting hole 12c and the pipe
fitting hole 12e have the concentric circle with each other and
also the first pipe 14 has a circular shape at cross section, as
shown in FIG. 4, the first pipe 14 supplies the first pipe sealing
member 12 with uniform contact pressure when the first pipe sealing
member 12 is closely fitted into the first circular hole 19.
[0062] Therefore, the first pipe sealing member 12 firmly supplies
the marginal portion S1 of the first circular hole 19 of the tank
body 11 with further uniform contact pressure.
[0063] Now, the second pipe sealing member 13 is described in
detail. As shown in FIG. 1, while the second pipe sealing member 13
is closely fitted into the second circular hole 20 of the tank body
11, as shown in FIG. 5, the second pipe sealing member 13 basically
has the same structure as the first pipe sealing member 12. The
second pipe sealing member 13 basically includes a flange 13a, a
retaining portion 13b, a closely fitting portion 13c, a tapered
collar 13d, a pipe fitting hole 13e, a tapered surface 13f and a
collared surface 13g.
[0064] Also, the second pipe sealing member 13 is obtained by
integrally molding elastic material similarly to the first pipe
sealing member 12.
[0065] As shown in FIG. 5, in the present embodiment, the second
pipe sealing member 13 includes the second pipe 15, which is bent.
The second pipe 15 is bonded to the second pipe sealing member 13.
Thereby, the second pipe sealing member 13 and the second pipe 15
are integrated with each other.
[0066] Now, a process of assembling the resin tank 10 according to
the present embodiment will be described.
[0067] To begin with, the first pipe sealing member 12 is fitted
into the first circular hole 19 of the tank body 11.
[0068] In the above stage, the first pipe 14 is not fitted to the
first pipe sealing member 12. In addition, the first pipe sealing
member 12 is made of elastic material. Further, the tapered collar
12d is formed on the first pipe sealing member 12. Therefore, the
first pipe sealing member 12 is easily fitted into the first
circular hole 19 of the tank body 11. Meanwhile, it is not
necessarily mentioned that the first pipe sealing member 12 is
sufficiently closely fitted into the first circular hole 19.
[0069] Subsequently, the first pipe 14 is fitted to the first pipe
sealing member 12 by inserting the first pipe 14 into the pipe
fitting hole 12e of the first pipe sealing member 12.
[0070] When the first pipe 14 is fitted to the first pipe sealing
member 12, the diameter of the pipe fitting hole 12e of the first
pipe sealing member 12 is slightly increased by elasticity of the
elastic material of the first pipe sealing member 12.
[0071] Thus, the first pipe 14 supplies the first pipe sealing
member 12 with uniform contact pressure. Thereby, the first pipe
sealing member 12, which receives uniform contact pressure from the
first pipe 14, firmly supplies the marginal portion S1 of the first
circular hole 19 with uniform contact pressure in accordance with
the elastic force of the first pipe sealing member 12 and force
resulting from the contact pressure, which is supplied from the
first pipe 14. At this point in time, the first pipe sealing member
12 is closely fitted into the first circular hole 19.
[0072] The diameter of the first circular hole 19 is slightly
increased mainly by deformation of the stepped potion 21, to which
elastic force of the first pipe sealing member 12 is applied, when
the uniform contact pressure is supplied to the marginal portion S1
of the first circular hole 19 by the first pipe sealing member 12.
Thereby, inconvenience such as a excessive deformation or a crack
is not caused to the tank body 11 and thus the function of the
resin tank 10 is maintained.
[0073] Thus, when the uniform contact pressure is supplied to the
marginal portion S1 of the first circular hole 19, as shown in FIG.
4, the uniform contact pressure is supplied to the closely fitting
portion 12c of the first pipe sealing member 12 so as to resist the
contact pressure, which is supplied from the first pipe sealing
member 12.
[0074] In contrast, when the first pipe sealing member 12 and the
first pipe 14 are detached from the tank body 11, the first pipe 14
is first drawn out of the first pipe sealing member 12 and then the
first pipe sealing member 12 is drawn out of the first circular
hole 19.
[0075] Now, the second pipe sealing member 13 is fitted into the
second circular hole 20 of the tank body 11. While the first pipe
sealing member 12 is fitted into the first circular hole 19 and
then the first pipe 14 is inserted into the pipe fitting hole 12e
of the first pipe sealing member 12, the second pipe 15 is already
installed in the second pipe sealing member 13 before the second
pipe sealing member 13 is fitted into the second circular hole 20
of the tank body 11. Therefore, fitting the second pipe sealing
member 13, in which the second pipe 15 is already installed, into
the second circular hole 20 is slightly harder than fitting the
first pipe sealing member 12 into the first circular hole 19.
However, since the second pipe sealing member 13 is also made of
elastic material and the tapered collar 13d is also formed on the
second pipe sealing member 13, the second pipe sealing member 13 is
also relatively easily fitted into the second circular hole 20.
[0076] In a state that the second pipe sealing member 13 is
completely fitted into the second circular hole 20, the second pipe
sealing member 13 has already supplied the marginal portion S2 of
the second circular hole 20 with uniform contact pressure and has
been closely fitted into the second circular hole 20.
[0077] In contrast, when the second pipe sealing member 13 is
detached from the tank body 11, the second pipe sealing member 13
is merely drawn out of the second circular hole 20.
[0078] In the resin tank 10 according to the present embodiment,
the connection between the first pipe 14 and the tank body 11 is
materialized to each other by closely fitting the first pipe
sealing member 12 into the first circular hole 19 of the tank body
11. The closely fitting portion 12c of the first pipe sealing
member 12 supplies the marginal portion S1 of the first circular
hole 19 with uniform contact pressure, and thereby ensures sealing
performance of the first pipe sealing member 12 that serves as a
sealing member.
[0079] Also, as the temperature of the hydraulic fluid in the tank
body 11 rises and falls, thermal stress is caused to the tank body
11. At this time, while the magnitude of the contact pressure,
which is supplied to the marginal portion S1 of the first circular
hole 19 of the tank body 11 by the first pipe sealing member 12,
varies, uniformity of the contact pressure, which is supplied to
the marginal portion S1 of the first circular hole 19 of the tank
body 11, is maintained.
[0080] Further, the relation between the second pipe sealing member
13 and the second circular hole 20 is described similarly to the
above relation between the first pipe sealing member 12 and the
first circular hole 19.
[0081] In the present embodiment, the following advantageous
effects are obtained.
[0082] (1) Since the first pipe sealing member 12 is closely fitted
into the first circular hole 19, the first pipe sealing member 12
supplies the marginal portion S1 of the first circular hole 19 with
the uniform contact pressure. Thereby, the first pipe sealing
member 12 accurately seals the first circular hole 19. Thus, the
hydraulic fluid does not leak though an aperture between the first
circular hole 19 and the first pipe sealing member 12. Also, since
the second pipe sealing member 13 is closely fitted into the second
circular hole 20, the second pipe sealing member 13 supplies the
marginal portion S2 of the second circular hole 20 with the uniform
contact pressure. In a similar manner, the hydraulic fluid does not
leak though an aperture between the second circular hole 20 and the
second pipe sealing member 13.
[0083] (2) Each of the first pipe 14 and the second pipe 15 is
connected to the tank body 11 by simply using the first pipe
sealing member 12 and the second pipe sealing member 13. Thereby,
the number of parts of the resin tank 10 is drastically reduced. In
addition, assembly work of the resin tank 10 is easily achieved by
reducing the number of parts.
[0084] (3) The first pipe sealing member 12 and the second pipe
sealing member 13 are made of elastic material. Also, the first
pipe sealing member 12 and the second pipe sealing member 13
respectively has the tapered collar 12d and the tapered collar 13d.
Therefore, the first pipe sealing member 12 is simply attached to
or detached from the first circular hole 19. Also, the second pipe
sealing member 13 is simply attached to or detached from the second
circular hole 20. Thereby, assembly work of the resin tank 10 is
efficiently achieved.
[0085] (4) The resin tank 10 has the tank body 11, which is made of
resin and in which many curved surfaces are used. In addition, the
first circular hole 19 and the second circular hole 20 are formed
in the tank body 11. Therefore, the resin tank 10 reasonably
absorbs the thermal stress of the tank body 11, which is caused by
rise and fall of temperature of the hydraulic fluid, and the
contact pressure, which is supplied to the tank body 11 by the
first pipe sealing member 12 and the second pipe sealing member
13.
[0086] (5) The first pipe sealing member 12 supplies the first pipe
14 with the uniform contact pressure while supplying the marginal
portion S1 of the first circular hole 19 with the uniform contact
pressure. Therefore, the first pipe 14 is reliably fixed to the
first pipe sealing member 12.
[0087] A resin tank 30 according to a second preferred embodiment
of the present invention will now be described with reference to
FIGS. 6A and 6B.
[0088] In the present embodiment, the resin tank 30 has a third
pipe sealing member 32 that is different from the first pipe
sealing member 12 and the second pipe sealing member 13 according
to the first embodiment while having a tank body 31 that is
structured basically similarly to the tank body 11 according to the
first embodiment.
[0089] As shown in FIG. 6A, the tank body 31 has a third circular
hole 33 whose diameter is relatively large and a third stepped
portion 35 annularly formed thereon.
[0090] Meanwhile, in the present embodiment, the third pipe sealing
member 32 includes a flange 32a, a retaining portion 32b, a closely
fitting portion 32c, a tapered collar 32d, a pipe fitting hole 32e,
a tapered surface 32f and a collared surface 32g similarly to the
first embodiment. However, as shown in FIG. 6B, the number of the
pipe fitting holes 32e is four and the number of the third pipes
34, which are respectively fitted to the third pipe sealing member
32, is four. Thereby, the third pipes 34 are respectively fitted
into the pipe fitting holes 32e. In this regard, the third pipe
sealing member 32 according to the second embodiment is different
from the first pipe sealing member 12 and the second pipe sealing
member 13 according to the first embodiment.
[0091] These pipe fitting holes 32e are formed in the third pipe
sealing member 32 in such a manner that the distances between each
pipe fitting hole 32e and the middle of the third pipe sealing
member 32 become equal to each other. Thereby, in a state that the
third pipe sealing member 32 is closely fitted into the third
circular hole 33 of the tank body 31, the contact pressure, which
is supplied to a marginal portion S3 of the third circular hole 33
by the third pipe sealing member 32, is uniformed as far as
possible.
[0092] In the present embodiment, the third pipe sealing member 32
is first fitted into the third circular hole 33 similarly to the
first pipe sealing member 12 of the first embodiment, and then the
third pipe sealing member 32 is closely fitted into the third
circular hole 33 of the tank body 31 by fitting each of the third
pipes 34 into the corresponding pipe fitting hole 32e.
[0093] In the present embodiment, when the third pipe sealing
member 32 is closely fitted to the tank body 31, the similar action
to the first pipe sealing member 12 of the first embodiment is
substantially obtained. Therefore, the description of the action is
omitted.
[0094] In the present embodiment, the similar effects (1), (2),
(3), (4) and (5) to the first embodiment are substantially
obtained. In addition, the following advantageous effects are
obtained.
[0095] (6) Since a plurality of the third pipes 34 is fitted into
the third pipe sealing member 32, the plurality of third pipes 34
is connected to the tank body 31 by simply fitting the third pipe
sealing member 32 into the third circular hole 33. Thereby, the
resin tank 30 is simply assembled.
[0096] (7) Since the number of the third circular holes 33, which
are formed in the tank body 31, and the number of the third pipe
sealing members 32 are reduced, the manufacturing cost of the tank
body 31 is reduced. Thereby, the manufacturing cost of the resin
tank 30 is reduced.
[0097] In the present invention, the following alternative
embodiments are also practiced.
[0098] In the first embodiment, the first pipe 14 and the second
pipe 15 are connected to the tank body 11 respectively by using the
first pipe sealing member 12 and the second pipe sealing member 13.
In an alternative embodiment to the first embodiment, the inlet 16
and the outlet 17 of the tank body 11 are not tubularly formed. An
inlet is structured by forming a circular hole in the tank body 11
and by using a pipe sealing member and a pipe. Also, an outlet is
structured by forming a circular hole in the tank body 11 and by
using a pipe sealing member and a pipe. In this case, the pipe
sealing members of the inlet and the outlet are exchanged to each
other. Also, the pipes of the inlet and the outlet are exchanged to
each other. Thereby, convenience of maintenance of the resin tank
is improved.
[0099] In the first embodiment, the second pipe sealing member 13
and the second pipe 15, which is manufactured separately from the
second pipe sealing member 13, are integrated with each other by
bonding the second pipe 15 to the second pipe sealing member 13. In
an alternative embodiment to the first embodiment, both of the
second pipe sealing member 13 and the second pipe 15 are made of
the same material, and are integrally molded with each other. In
this case, bonding the second pipe 15 to the second pipe sealing
member 13 is not needed. Thereby, the manufacturing cost of the
resin tank is reduced.
[0100] In the second embodiment, the number of the pipe fitting
holes 32e, which are formed in the third pipe sealing member 32, is
four and each of the third pipes 34 is freely attached to or
detached from the corresponding pipe fitting holes 32e. In an
alternative embodiment to the second embodiment, each of the third
pipes 34 is bonded to or integrally molded with the third pipe
sealing member 32. Thereby, each of the third pipes 34 is
integrated with the third pipe sealing member 32. In this case,
since the number of parts is reduced, the manufacturing cost of the
resin tank 30 is reduced. In addition, the number of the third
pipes 34 and the number of the pipe fitting holes 32e are not
restricted to four, respectively.
[0101] In the second embodiment, the diameters of the third pipes
34 are equal to each other. In an alternative embodiment to the
second embodiment, the diameters of pipes are different from each
other and pipe fitting holes are formed in a pipe sealing member so
as to meet the diameters of the corresponding pipes, respectively.
In this case, the arrangement of each pipe fitting hole requires
considering in such a manner that the pipe sealing member supplies
the marginal portion of a circular hole of the tank body with
uniform contact pressure when the pipe sealing member is closely
fitted into the circular hole of the tank body.
[0102] In the first embodiment, the first circular hole 19 and the
second circular hole 20 are formed in the top face of the tank body
11. In the second embodiment, the third circular hole 33 is formed
in the top face of the tank body 31. In alternative embodiments to
the first and second embodiments, at least a circular hole is
formed in the side face of the tank body. In addition, the location
of the circular hole and the number of the circular holes are not
restricted.
[0103] In the first embodiment, the first pipe 14, which is fitted
to or bonded to the first pipe sealing member 12, has the surface
of an outside diameter and the surface of an inside diameter that
are concentric with each other. The second pipe 15, which is fitted
to or bonded to the second pipe sealing member 13, has the surface
of an outside diameter and the surface of an inside diameter that
are concentric with each other. Also, in the second embodiment,
each of the third pipes 34, which is fitted to or bonded to the
third pipe sealing member 32, has the surface of an outside
diameter and the surface of an inside diameter that are concentric
with each other. In alternative embodiments to the first and second
embodiments, at least a pipe has the surface of an outside diameter
and the surface of an inside diameter that are eccentric with each
other. Even in this case, a pipe sealing member supplies a marginal
portion of a circular hole with uniform contact pressure.
[0104] In alternative embodiments to the above embodiments, when
the pipe, which is installed in the pipe sealing member, faces the
inside or the outside of the tank body, and when the pipe is tilted
or bent relative to the tank body, if the pipe or the pipe sealing
member is pivoted respectively relative to the pipe fitting hole or
the circular hole, the location of the pipe relative to the tank
body is adjusted.
[0105] In the first embodiment, the first pipe 14 is fitted to the
first pipe sealing member 12 after the first pipe sealing member 12
is fitted into the first circular hole 19. In an alternative
embodiment to the first embodiment, the first pipe 14 is previously
fitted to the first pipe sealing member 12. The first pipe sealing
member 12 is fitted into the first circular hole 19 together with
the first pipe 14. Thereby, the first pipe sealing member 12 and
the first pipe 14 are closely fitted to each other.
[0106] In the first and second embodiments, an oil tank, which is
installed in a forklift truck serving as an industrial vehicle, is
adopted as the resin tank. In alternative embodiments to the first
and second embodiments, an altitudinal maintenance-vehicle, which
has a hydraulic circuit, or a construction machine is adopted as
the resin tank.
[0107] In the first embodiment, each of the first pipe 14 and the
second pipe 15 is made of metallic material. In an alternative
embodiment to the above embodiment, an oil-resistant resin pipe is
adopted in place of each pipe made of metallic material. In
addition, as long as the function of a pipe is maintained, material
of the pipe is appropriately selected.
[0108] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein but may be modified
within the scope of the appended claims.
* * * * *