Patent Grant
9956730
The present invention relates to a compressor system capable of controlling the pressure of compressed air supplied to an object to be filled with air, at a specified pressure or lower without using a relief valve, and a puncture repair kit using the same.
As a puncture repair kit for emergency repairing a puncture, that shown in
As shown in
The compressor system (a) has a cylinder f in which a piston e is reciprocably disposed. The cylinder f is provided therein with a pump chamber f1 in which air is compressed between the piston e and itself, and a surge chamber f2 for receiving the compressed air compressed in the pump chamber f1 through an air release valve (not shown).
To the surge chamber f2, a relief valve g is connected in order to release excessive pressure if the supply pressure of the compressed air increased over the specified pressure.
In general, the specified pressure is set at the permissible maximum pressure of the tire in order to prevent the tire from being damaged by inflating over the specified pressure.
On the other hand, as shown in
The valve casing i is provided with a central hole h of which anterior end forms an air intake port h1 (see for example patent document 2). In the central hole h, there are disposed
a valving element k for opening and closing the air intake port h1, and a coiled spring n biasing the valving element k toward the air intake port h1.
An adjusting cap j having an exhaust hole j1 is threadedly engaged with the posterior end of the central hole h so as to move back and forth freely.
When the relief valve g is assembled, the biasing force of the coiled spring n is adjusted by rotating the adjusting cap j to move back and forth so that the relief valve g opens at the specified pressure (relief valve set pressure).
As explained above, a relief valve g has a large number of components, and the adjusting operation is required for every relief valve when assembled. Therefore, the production requires much time and labor which is one factor of a decrease in the productivity and an increase in the production cost of the compressor system.
During the puncture sealant is injected into the tire T by the use of the compressor system (a), if an abnormal operating condition such that a tire valve part becomes clogged occurs, the pressure in the reservoir bottle b1 is gradually increased, and if over the specified pressure (relief valve set pressure), the relief valve g opens to release excessive pressure. However, this has a problem such that, since the pressure is dropped when the compressed air is discharged from the relief valve g, the puncture sealant in the reservoir bottle b1 flows reversely toward the surge chamber f2 and runs out from the relief valve g together with the air having the excessive pressure.
In particular, in a puncture repair kit in which a compressor system (a) is directly connected to a compressor system (a), the flow passage from a reservoir bottle b1 to a surge chamber f2 is short, therefore, the problem of the reverse flow becomes larger. Therefore, as disclosed in the patent document 1, an one-way valve r for preventing a reverse flow is conventionally disposed in the first flow passage c1.
However, similarly to the relief valve g, the one-way valve r has a large number of components. This becomes a factor of an increase in the production cost.
Patent document 1: JP-A-2010-249010
Patent document 2: JP-A-2012-101450
A first object of the present invention is to provide a compressor system, which can control the pressure of compressed air supplied to an object to be filled with air, at a specified pressure or lower although a relief valve is eliminated, and which can achieve an improvement in the productivity and a cost-cutting while assuring safety by preventing damage of the object to be filled with air due to overpressure.
A second object of the present invention is to provide a puncture repair kit, in which the reverse flow of the puncture sealant toward the compressor system is prevented and a one-way valve can be eliminated, and which can further achieve the improvement in the productivity and the cost-cutting in addition to the above-mentioned merits.
A first invention in the present application is a compressor system, in which a supply pressure of compressed air is controlled at a specified pressure PP or less without using a relief valve, and which is characterized by having
a motor,
a piston driven by the motor through a crank mechanism,
a cylinder having
a cylinder main body forming a pump chamber housing the piston reciprocably from a lower dead point to a top dead point and compressing air between the piston and itself, and
a cylinder subpart forming a surge chamber for receiving the compressed air compressed in the pump chamber through an air release valve,
an air intake valve having an air intake hole penetrating through the piston to take outside air into the pump chamber, and a valving element formed from a leaf spring closing a pump chamber side of the air intake hole with its elasticity, and
an air supplying passage for sending and supplying the compressed air from the surge chamber toward outside, wherein
the compression volume V2 satisfies the following expression (1), and
the diameter D of the air intake hole is 3 to 15 mm,
0.8×{V1×P0/(PP−P0)}=<V2<1.0×{V1×P0/(PP−P0)} (1)
wherein
V1 is a stroke volume which is a cylinder volume during the piston moves from the lower dead point to the top dead point,
V2 is a compression volume which is a cylinder volume when the piston is at the top dead point, and
P0 is an atmospheric pressure.
A second invention in the present application is a puncture repair kit, which has
the compressor system in the first invention, and
a bottle unit in which a cap is attached to a mouth portion of a reservoir bottle containing a puncture sealant, and which is characterized in that
the cap has
an air intake port portion for feeding the compressed air from the compressor system into the reservoir bottle through a first flow passage, and
an output port portion for sequentially taking out the puncture sealant and the compressed air from the reservoir bottle through a second flow passage upon feeding of the compressed air, and
the first flow passage is not provided with a one-way valve for preventing the puncture sealant from flowing reversely toward the compressor system.
By the way, the above-mentioned pressure PP, P0 is an absolute pressure.
In the first and second inventions, the compression volume V2 of the cylinder of the compressor system satisfies the expression (1).
According to Boyle's law, a product {P0×(V1+V2)} of the pressure and volume of the air in the cylinder under such a state that air is sucked in the cylinder at the lower dead point becomes equal to a product (Pmax×V2) of the pressure and volume of the air in the cylinder under such a state that the air is compressed to the maximum pressure Pmax at the top dead point. Therefore, the following expression (A) is obtained. From this expression (A), the compression volume V2 is given by the expression (B).
Pmax×V2=P0×(V1+V2) (A)
V2=(P0×V1)/(Pmax−P0) (B)
On the other hand, when the air pressure in the surge chamber is gradually increased and becomes equal to the maximum pressure Pmax, the pressure on the inside of the air release valve becomes equal to that on the outside thereof. Therefore, the compressed air in the cylinder becomes not discharged toward the surge chamber and remains in the cylinder. In other words, although the piston is operated, the intake of air into the cylinder and the discharge of air from the cylinder are not took place. The supply pressure of the compressor system is prevented from increasing over the maximum pressure Pmax in the cylinder.
Accordingly, by setting the specified pressure PP of the compressor system at the maximum pressure Pmax, the supply pressure of the compressor system can be controlled at the specified pressure PP or less without using a relief valve.
The compression volume V2 for that purpose can be given by the following expression (C).
V2=(P0×V1)/(PP−P0) (C)
In practice, however, affected by the air intake valve, there is a tendency that the volume of the sucked air at the lower dead point becomes less. Accordingly, the compression volume V2 in actuality needs to be set at a value less than (P0×V1)/(PP−P0).
However, if the compression volume V2 is too small, another problem arises such that the opening and closing of the air intake valve are delayed, and the exhaust efficiency is lowered. In the present invention, therefore, by limiting the diameter of the air intake hole to reduce the intake resistance due to the air intake valve as far as possible, the compression volume V2 not less than 0.8 times the (P0×V1)/(PP−P0) is secured, and thereby the lowering of the exhaust efficiency is prevented.
A relief valve is eliminated. Accordingly, in the puncture repair kit employing the compressor system, even under abnormal operating condition such that a tire valve part is clogged during repairing the puncture, the pressure in the reservoir bottle is the same as the pressure in the surge chamber and, they are equal to the specified pressure. Accordingly, the reverse flow of the puncture sealant toward the surge chamber is not occurred. Thus, a one-way valve can be eliminated from the first flow passage.
Embodiments of the present invention will now be described in detail.
As shown in
In the compressor system 2, as shown in
The compressor main portion 4 has at least a motor M, a piston 5, a cylinder 7, an air intake valve 12 (shown in
The piston 5 is connected to the motor M through a crank mechanism 11.
The cylinder 7 houses the piston 5 reciprocably.
The air intake valve 12 is attached to the piston 5.
The air supplying passage 8 sends and supplies the produced compressed air toward the bottle unit 3.
The storage case 9 in this example is formed as a flat box with a small height in the form of a substantially rectangular parallelepiped, which can be disassembled into upper and lower casing parts.
As the motor M, commercially-supplied various DC motors operable with a 12 volt direct-current power supply of an automobile can be employed.
A power cord, which is provided at one end with a power plug 10 connectable with a cigarette lighter socket in an automobile, is connected to the motor M through a power on/off switch SW attached to an upper plate part of the storage case 9.
As to the crank mechanism 11, those having various known structures are usable.
The cylinder 7 has a cylinder main body 7A and a cylinder subpart 7B as shown in
The cylinder main body 7A houses the piston 5 reciprocably from the lower dead point PL (shown in
The cylinder subpart 7B is connected to the cylinder main body 7A and forms a surge chamber 6B for receiving the compressed air compressed in the pump chamber 6A through an air release valve 13.
The surge chamber 6B dampens pulsation of the compressed air from the pump chamber 6A to stabilize the pressure.
The cylinder subpart 7B is provided with coupling portions 15 and 16.
A pressure indicator 17 for measuring the pressure in the surge chamber 6B is connected to one coupling portion 15.
The coupling portion 16 is provided with the air supplying passage 8.
In this example, the bottle unit 3 is connected to the end of the coupling portion 16 directly without using a hose.
The air release valve 13 is composed of a through hole 13A, a valving element 13B for example made of a rubber member, and a spring means 13c in the form of a coiled spring.
The through hole 13A communicates between the pump chamber 6A and the surge chamber 6B.
The valving element 13B opens and closes a surge chamber 6B side of the through hole 13A.
The spring means 13c is disposed between the valving element 13B and a lid part 7B1 of the cylinder subpart 7B to bias the valving element 13B toward the through hole 13A.
By pressurizing the pump chamber 6A, the air release valve 13 is operated to close the through hole 13A.
The operating force at this time is preferably set to be as small as possible, for example, not more than 80 kPa, more preferably not more than 50 kPa when it is converted into the pressure on the valving element 13B.
The air intake valve 12 has an air intake hole 12A penetrating through the piston 5 to take outside air into the pump chamber 6A, and a valving element 12B closing a pump chamber 6A side of the air intake hole 12A with its elasticity. In particular, the valving element 12B is a metal leaf spring as shown in
a covering part 12B2 being substantially disk-shaped and covering the air intake hole 12A, and
a constricted part 12B3 disposed therebetween.
By the constricted part 12B3, elasticity deformation is facilitated.
When moving downward from the top dead point PU, owing to a negative pressure in the pump chamber 6A, the air intake hole 12A is opened, and outside air is sucked into the pump chamber 6A.
When moving upward from the lower dead point PL, owing to the elasticity of the valving element 12B and the pressurization of the inside of the pump chamber 6A, the air intake hole 12A can be closed.
In the present invention, in order to control the supply pressure of the compressed air from the compressor system 2 at the specified pressure PP or less without using a relief valve, the compression volume V2 of the cylinder 7 is set to be more than a conventional volume and within a range expressed by the following expression (1).
Given that, as shown in
V1 is a stroke volume which is a cylinder volume during the piston 5 moves from the lower dead point PL to the top dead point PU,
V2 is a compression volume which is a cylinder volume when the piston 5 reaches the top dead point PU, and
P0 is the atmospheric pressure,
the compression volume V2 is set within a range satisfying the following expression (1)
0.8×{V1×P0/(PP−P0)}=<V2<1.0×{V1×P0/(PP−P0)} (1).
According to Boyle's law, a product {P0×(V1+V2)} of the pressure and volume of the air in the cylinder 7 under such a state that air is sucked in the cylinder 7 at the lower dead point PL becomes equal to a product (Pmax×V2) of the pressure and volume of the air in the cylinder 7 under such a state that the air is compressed to the maximum pressure Pmax at the top dead point PU. Therefore, the following expression (A) is obtained. From this expression (A), the compression volume V2 is given by the expression (B).
Pmax×V2=P0×(V1+V2) (A)
V2=(P0×V1)/(Pmax−P0) (B)
On the other hand, when the air pressure in the surge chamber 6B is gradually increased and becomes equal to the maximum pressure Pmax, the pressure on the inside of the air release valve 13 becomes equal to that on the outside thereof. Therefore, the compressed air in the cylinder 7 becomes not discharged toward the surge chamber 6B and remains in the cylinder 7. In other words, although the piston 5 is operated, the intake of air into the cylinder 7 and the discharge of air from the cylinder are not took place. The supply pressure of the compressor system 2 is prevented from increasing over the maximum pressure Pmax.
Accordingly, by setting the specified pressure PP of the compressor system 2 at the maximum pressure Pmax, the supply pressure of the compressor system 2 can be controlled at the specified pressure PP or less without using a relief valve. The compression volume V2 for that purpose can be given by the following expression (C) theoretically
V2=(P0×V1)/(PP−P0) (C).
In the case of the compressor system for repairing puncture of a tire or for pumping up a tire, it is preferable to use, as the specified pressure PP, the permissible maximum pressure for the tire, for example,
451.3 kPa (if converted to a gauge pressure, 350 kPa) in the case of a passenger car tire,
701.3 kPa (if converted to a gauge pressure, 600 kPa) in the case of a light truck tire,
901.3 kPa (if converted to a gauge pressure, 800 kPa) in the case of a heavy duty tire.
In practice, however, affected by the air intake valve 12, there is a tendency that the volume of the sucked air at the lower dead point P1 becomes less. Accordingly, the compression volume V2 in actuality needs to be set at a value less than (P0×V1)/(PP−P0).
However, if the compression volume V2 is too small, another problem arises such that the opening and closing of the air intake valve 12 are delayed, and the exhaust efficiency is remarkably lowered.
In the present invention, therefore, by limiting the diameter D (shown in
More specifically, the diameter D of the air intake hole 12A is limited in the range of 3 to 15 mm.
If the diameter D becomes less than 3 mm, the intake volume becomes insufficient, causing a decrease in the exhaust efficiency of the compressor.
If the diameter D becomes more than 15 mm, since the valving element 12B is made form a thin leaf spring, the tight sealing of the air intake hole 12A is impaired, causing a decrease in the exhaust efficiency.
Therefore, it is preferable that the lower limit of the diameter D is not less than 5 mm, and the upper limit is not more than 10 mm.
In this case, it is preferable that the thickness t (shown in
If the thickness t is less than 0.05 mm, the rigidity of the valving element 12B becomes insufficient, and the tight sealing of the air intake hole 12A is impaired, which causes a decrease in the exhaust efficiency.
Based on these standpoints, the lower limit of the thickness t is more preferably not less than 0.07 mm, and
the upper limit is more preferably not more than 0.15 mm. From the same standpoints, it is preferable that
the width W (shown in
For the valving element 12B, a stainless material especially superior in the corrosion resistance can be suitably used.
It is preferable that the covering part 12B2 is formed to have a diameter 1 to 5 mm larger than the diameter D of the air intake hole 12A.
The bottle unit 3 is as shown in
In the reservoir bottle 18, as shown in
The cap 19 has an intake port portion 41 capable of directly connecting to an outlet mouth portion 16A at the end of the coupling portion 16 of the compressor system 2 so as to feed the compressed air from the outlet mouth portion 16A into the reservoir bottle 18, and
an output port portion 42 for sequentially taking out the puncture sealant and compressed air from the reservoir bottle 18 upon feeding the compressed air.
In particular, the cap 19 has a cap main portion 19A which integrally has a bottom plate part 31 defining a bottom face, a bottle mounting part 32 on which the mouth portion 18A of the reservoir bottle 18 is mounted, and a constricted part 33 disposed therebetween.
In the cap main portion 19A, there are formed
a first flow passage 35 extending from the intake port portion 41 into the mouth portion 18A of the reservoir bottle 18, and
a second flow passage 36 extending from the output port portion 42 into the mouth portion 18A of the reservoir bottle 18.
The bottle mounting part 32 has a reentrant mounting portion 32A to which the mouth portion 18A is fixed, and a boss portion 32B protruding from the bottom face of the reentrant mounting portion 32A.
The reentrant mounting portion 32A can be fixed to the mouth portion 18A by screwing an inside screw formed on the inside wall surface.
In the upper surface of the boss portion 32B, opened are a first flow passage upper opening 35a defining the upper end of the first flow passage 35, and
a second flow passage upper opening 36a defining the upper end of the second flow passage 36.
The intake port portion 41 in this example is a connection nozzle protruding from the constricted part 33 toward the outlet mouth portion 16A.
As shown in
Such a construction that the coupling portion 16 is connected to the intake port portion 41 through a hose may be also possible.
The puncture repair kit1 in this example is provided with a lock mechanism 34 in order to prevent a surrounding area from being tainted with the puncture sealant as a result of disconnection of the outlet mouth portion 16A from the intake port portion 41 during repairing puncture.
The lock mechanism 34 is composed of a engaging means 34A formed on the cap 19, and a fall-out prevention means 34B formed on the compressor system 2.
In this example, the engaging means 34A is composed of a pair of engaging claws 45 which protrude toward the compressor system 2 on both sides (in this example, upper side and under side) of the intake port portion 41, and which are each provided at the tip with a hook portion in the form of a right-angled triangle. In this example, the fall-out prevention means 34B has claw engaging holes 46 which are disposed at positions opposite to the engaging claws 45, and which can engage with the engaging claws 45 to prevent from falling out.
In the puncture repair kit 1 like this, the compressor system 2 has no relief valve. Therefore, even under abnormal operating condition such that a tire valve part is clogged during injecting the puncture sealant, the pressure in the reservoir bottle 18 and the pressure in the surge chamber 6B do not increase over the specified pressure PP, and become equal to each other. Therefore, the reverse flow of the puncture sealant from the reservoir bottle 18 toward the surge chamber 6B is not occurred. Accordingly, the first flow passage 35 of the bottle unit 3 is not provided with a one-way valve preventing the reverse flow of the puncture sealant.
While description has been made of particularly preferable embodiments of the present invention, the present invention can be carried out by modifying into various embodiments without being limited to the illustrated embodiments.
(1) In order to confirm the effects of the present invention, compressor systems having the structure shown in
Then, each compressor system was connected to a tire, and the maximum pressure P when the compressor system in its operating condition was left unattended, was measured with the pressure indicator 17 attached to the cylinder subpart 7B.
For comparison, with respect to a conventional compressor system (Conventional example) having a relief valve of which relief valve set pressure was set at 451.3 kPa (if converted to a gauge pressure, 350 kPa), the same test was carried out and the maximum pressure P of the compressor system was measured.
The compressor systems had substantially same specifications except for those shown in the table, and
a leaf spring made from metal (stainless) having a nearly gourd shape (the width of the constricted part, 7 mm) was used as the valving element 12B of the air intake valve 12.
The operating force of the air release valve 13 (converted into the pressure on the valving element) was 30 kPa.
Exhaust efficiency: A ratio To/T×100(%) was compared as the exhaust efficiency, wherein
TO is the time required for Conventional example to increase the tire air pressure up to 250 kPa (gauge pressure), and
T is the time required for embodiment, and
the power voltage was 12 volts.
The larger the value, the better the exhaust efficiency.
As shown in the table, it was confirmed that the compressor systems as Embodiments could control the pressure of the compressed air supplied to the tire (object to be filled with air) at the substantially specified pressure without using a relief valve, while maintaining high exhaust efficiency.
(2) The compressor system as Conventional example in Table 1, to which a bottle unit having the structure shown in
As a result, it was observed that the puncture sealant spouted from the relief valve together with the compressed air when the relief valve was operated in the state left unattended.
In addition, the compressor system as Embodiment 1 in Table 1, to which the bottle unit having the structure shown in
As a result, the occurrence of leakage of the puncture sealant in the state left unattended was not observed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-237051 | Oct 2012 | JP | national |
| 2012-237052 | Oct 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/078299 | 10/18/2013 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/065208 | 5/1/2014 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7547201 | Chou | Jun 2009 | B2 |
| 8562306 | Kojima | Oct 2013 | B2 |
| 8997801 | Kojima | Apr 2015 | B2 |
| 20070077157 | Chou | Apr 2007 | A1 |
| 20100267298 | Tawa et al. | Oct 2010 | A1 |
| 20110038738 | Kojima | Feb 2011 | A1 |
| Number | Date | Country |
|---|---|---|
| 61-192877 | Aug 1986 | JP |
| 2002-61578 | Feb 2002 | JP |
| 2004-190625 | Jul 2004 | JP |
| 2010-89273 | Apr 2010 | JP |
| 2011-126185 | Jun 2010 | JP |
| 2010-162847 | Jul 2010 | JP |
| 2010-164033 | Jul 2010 | JP |
| 2010-249010 | Nov 2010 | JP |
| 2012-101450 | May 2012 | JP |
| 2012-157974 | Aug 2012 | JP |
| WO2011055632 | May 2011 | WO |
| Entry |
|---|
| International Search Report, issued in PCT/JP2013/078299, dated Jan. 7, 2014. |
| Number | Date | Country | |
|---|---|---|---|
| 20150246490 A1 | Sep 2015 | US |
