JPS6049107A - Pressure-source apparatus for air-pressure circuit - Google Patents

Abstract

PURPOSE:To permit certain regeneration of desiccants by supplying the air for regeneration up to the time when the internal pressure of a storage tank for regeneration lowers to a prescribed pressure in comparison with the internal pressure in the storage tank for compressed air, when the desiccants in a dryer arranged between the storage tank for compressed air and an air compressor. CONSTITUTION:The air compressed in an air compressor 1 reaches a dryer 3 through a piping 5, and after moisture is removed, the air flows into a storage chamber 10 for regeneration in a compressed-air storage tank 14 through a valve apparatus 8 which is opened by the compressed-air pressure. The air is introduced into a main storage chamber 13 through a pipe 11 and supplied into the parts in demand through the piping 5. When the pressure in the main storage chamber 13 rises to a prescribed value, a discharge valve 22 is opened through a governor 17, and the compressor stops operation. Then, the condensed water on the bottom of the dryer 3 is discharged, and the dried air supplied from the storage chamber 10 is flowed reversely through a narrow passage between a valve seat 43 and a valve body 45 which is opened by the pressure difference between the lower chamber 36 and the upper chamber 35 which communicate to the storage chambers 10 and 13 respectively, and regeneration of the dryer 3 is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure source device for a pneumatic circuit provided for pneumatically operated equipment, particularly pneumatically operated equipment mounted on a vehicle or the like.

Conventionally, vehicles are equipped with various pneumatically operated devices that use compressed air, such as air brake devices and door opening/closing devices. Frozen brakes or rust may occur, causing malfunctions in pneumatically operated equipment.Especially in air brake systems, there is a risk that the brakes will not operate even if you try to apply them, resulting in no braking. Ta.

For this reason, conventionally, an air compressor that discharges compressed air, a storage tank that stores the air discharged from the air compressor, and a dryer that is disposed between the storage tank and the air compressor and contains a desiccant, a regeneration storage tank disposed between the dryer and the storage tank to store air for regeneration; a discharge valve for connecting the air compressor side of the desiccant to outside air in response to an external command; an operation adjustment mechanism that disables the operation of the air compressor and issues a command to the discharge valve when the pressure in the storage tank reaches the upper limit pressure until the pressure reaches the lower limit pressure; A pressure source of a pneumatic circuit is provided between the dryer and a shutoff valve that shuts off air movement from the regeneration storage tank to the dryer when the pressure on the regeneration storage tank side becomes less than a predetermined value. The device is in use.

In these devices, when the compressed air discharged from the air compressor passes through the dryer, moisture in the air is adsorbed by the desiccant, and the dried air is transferred to the storage tank and the regeneration storage tank. It can be stored in

When the pressure in the storage tank reaches the upper limit pressure, the operation of the air compressor is disabled by a command from the operation adjustment mechanism, the discharge valve is opened, and the drying air is discharged from the regeneration storage tank to the dryer. Backflow of air begins, then
The dry air continues to flow back until the pressure in the regeneration storage tank decreases from a pressure equal to the upper limit pressure in the storage tank to a predetermined pressure at which the shutoff valve closes.

At that time, the water absorbed by the desiccant is contained in the dry air flowing back and is discharged to the outside through the discharge valve to restore the dehumidifying ability of the desiccant, that is, to regenerate the desiccant. It looks like this.

By the way, in such regeneration of the desiccant, the shutoff valve is adjusted so that the amount of air necessary for regenerating the desiccant is obtained by the difference between the upper limit pressure of the storage tank internal pressure and the closing pressure of the shutoff valve. The valve closing pressure value is set with respect to the upper limit pressure value within a range of an upper limit pressure value and a lower limit pressure value of the pressure in the storage tank, which are preset by the operation adjustment mechanism. Since the mechanism and the shutoff valve can freely adjust their set pressure values independently of each other, the following problem occurs.

That is, the user of the vehicle or the like may arbitrarily adjust the operation adjustment mechanism to lower the upper limit pressure value in the storage tank than a preset value, or adjust the shutoff valve so that its closing pressure value is higher. If the pressure is adjusted to
There is a lack of dry air necessary for regenerating the desiccant,
This results in the problem that the desiccant is not regenerated sufficiently. In addition, the set pressure values of the operation adjustment mechanism and the cutoff valve are generally determined with tolerances within each, so that they vary unrelated to each other within the tolerance range each time they are operated. Therefore, the operation adjustment mechanism operates when the upper limit pressure value in the storage tank is lower by the tolerance, and the shutoff valve closes at a pressure higher than the set pressure value by the tolerance. As mentioned above, if the difference between the upper limit pressure in the storage tank and the closing pressure of the shutoff valve is substantially small, the desiccant will not be regenerated sufficiently.

The present invention has been made in view of the above problems, and includes:
The purpose of the present invention is to provide a pressure source device for a pneumatic circuit that can sufficiently regenerate the desiccant, and the pressure in the regeneration storage tank is controlled between the desiccant and the regeneration storage tank. A valve arrangement is provided for permitting movement of air from the regeneration reservoir toward the desiccant until the pressure decreases to a pressure determined by a predetermined relationship relative to the pressure within the desiccant.

By doing this, the upper limit pressure in the reservoir and the valve device f?, which are adjusted by the operation adjustment mechanism as in the conventional case, can be adjusted. The valve closing pressure of the valve device does not vary independently of each other, and the valve closing pressure of the valve device is automatically set successively in a predetermined relationship according to the upper limit pressure in the storage tank.

Therefore, even if the upper limit pressure in the storage tank 9 becomes lower than the preset upper limit pressure value due to manual adjustment of the operation adjustment mechanism, etc., the pressure in the regeneration storage tank will rise to the lower limit pressure. On the other hand, dry air can be continued to be sent from the regeneration storage tank to the desiccant until the pressure is reduced to a pressure determined by a predetermined relationship, so there is no shortage of dry air for regeneration as in the past. Therefore, one supply of desiccant can be sufficiently performed.

Hereinafter, the present invention will be explained in detail based on the illustrated embodiments.

The figure is a schematic diagram showing an embodiment of the present invention, showing a valve device in a sectional view.

In the figure, 1 is an air compressor driven by a motor such as a vehicle (not shown), and a discharge port 2 of this air compressor 1 is connected to a pipe 5 to a dryer 3 containing a desiccant. connected via. The outlet 6 of the dryer 3 is
It is connected to the inlet of the compressed air storage tank 14 via the wiring "ff?, j+- device 8 and piping 9. The compressed air storage tank 14 is connected to the regeneration lamp chamber 10 connected to the dryer 3 side and the main The two ridge chambers 10 and 13 are connected via a pipe 11 and a check valve 12 that allows air to move only from the regeneration lamp chamber 10 to the main control chamber 13.

The main control room 13 is connected to various pneumatic actuators (not shown) such as a brake device and a door opening/closing device mounted on a vehicle etc. via a pipe 15.
It is connected to the inlet 18 of the governor 17 which regulates the pressure inside. The outlet 19L1 of the governor 17 is connected to an unloader (not shown) of the air compressor 1 through a pipe 20, and is further connected to a discharge valve 22 provided at the bottom of the dryer 3 via a pipe 21 branched from the pipe 20.

The valve device 8 has a stepped cylinder hole 24 inside thereof, and a stepped cylinder hole 28 and a small diameter portion 29 that are slidably fitted into a large diameter hole 25 and an upper small diameter hole 26, respectively. A piston 27 with a piston 27 is movably arranged, and the end face of the small diameter portion 29 is connected to the step portion 30 provided in the upper small diameter hole portion 26.
The four surfaces can come into contact with a step 32 formed between the large diameter hole 25 and the lower small diameter hole 31. In this way, the cylinder hole 24 is connected to the upper chamber 33 and the lower chamber 36 by the stepped piston 27.
The upper chamber 33 communicates with the main control chamber 13 through a connecting hole 37 and piping 38 bored in the upper part of the main body 23, and the lower chamber 36 communicates with the main control chamber 13 in the axial direction of the cylinder hole 24.
It is connected to the dryer 3 side through an inlet hole 34 and piping 7 drilled in the lower part, and to the regeneration lamp chamber through an outlet hole 35 and piping 9 drilled in the side of the main body 23 toward the rear of the cylinder hole 24. 10 respectively. Inside the lower chamber 36, a columnar projection 39 extending from the lower end surface of the large diameter portion 28 of the stepped piston 27 toward the inlet hole 34 is fitted.
A valve element 40 that is integrally movable in the axial direction of the cylinder hole 24 is disposed therein. The base member 41 has 40 valve elements, 46 members 41, and a sealing part hole 42, and the base member 41 has a lower small diameter hole below the cylindrical part in which the columnar projection 39 is slidably fitted with a retainer. A synthetic rubber sealing member is provided with a hemispherical portion facing the tapered fP seat 43 that connects the peripheral wall 31 and the peripheral wall of the inlet hole 34, and can be seated on the hemispherical portion against the valve seat 43. 42 is fitted. 4
Reference numeral 4 denotes a spring stretched between the service piston 27 and the base member 41, and the valve element 40h is urged toward the valve seat 43 by this spring 44. Such a valve element 40 together with a valve seat 43 forms a valve 45 , which is opened until the stepped piston 27 has moved down a predetermined amount from the position where it abuts the stepped portion 30 of the main body 23 . The dryer 3 side and the regeneration storage chamber 10 side are communicated with each other through a relatively small gap with the valve seat 43, and the service piston 27 is moved downward by a predetermined amount or more. Ben II! After the element 40 is seated on the valve seat 43, the regeneration storage chamber 1 is opened from the dryer 3 side.
A check valve is formed that allows communication only to the 0 side. It looks like this. In the long stepped piston 27, the effective pressure receiving area S□ of the small diameter portion 29 on the upper chamber 33 side is the same as that of the large diameter portion 28 of the lower chamber 36.
It is formed smaller than the effective pressure receiving area S2 of (
An effective pressure receiving area difference of 8□-51) is provided.

In addition, in the figure, 4G is a communication hole that communicates the space formed by the small diameter portion 29 of the service piston 27 and the large diameter hole 25 of the cylinder hole 24 with the atmosphere, and a discharge pipe provided at the outlet of the four outlet valves. It is.

The operation of the above embodiment will be described below.

Now, assuming that the air compressor 1 is driven by a prime mover (not shown) and the pressure in the compressed air storage tank 14 is low, the air compressor IU compresses the atmosphere and releases compressed air from the discharge port 2. It is sent to piping 5.

The compressed air sent to this pipe 5 contains a lot of moisture, but when it passes through the dryer 3, the moisture is removed by the desiccant, and the dry compressed air is passed through the outlet 6. It flows into the pipe 7. At this time, the stepped piston 2 of the valve device 8
7 is moved downward and the valve 45 is closed, the compressed air that has flowed into the pipe 7 pushes up the valve element 40 against the biasing force of the spring 44, opening the valve 45 and causing the valve device 8 to open. It flows into the lower chamber 36 of. The compressed air then passes through the outlet hole 35. It flows into the regeneration lamp chamber 10 via the pipe 9, and further flows into the main storage chamber 13 via the pipe 11 while opening the check valve 12. The air that has flowed into the main storage chamber 13 also flows through the pipe 38. It flows into the upper chamber 33 of the valve device 8 via the connection hole 37 . In this way, by continuing to operate the air compressor l, the compressed air storage tank 14
The pressure in each system increases. At this time, the pressures in the royal chamber 36 of the valve device 80 and in the upper chamber 33 rise equally, but the effective pressure receiving area (s2-81) of the large diameter portion 28 and small diameter portion 29 of the stepped piston 27 increases. As the pressure is applied, the stepped piston 27 is pushed toward the upper chamber 33 and moves upwards. Along with this, the valve element 40 is pulled up by the stepped piston 27 and separated from the valve seat 43. Finally, the stepped piston 27 is still in contact with the stepped portion 30 of the main body 23 and the valve 45 is open, as shown in the figure.At this point, the air compressor 1 continues to send out compressed air, and the compressed air The pressure on the storage tank 14 side should continue to rise. When the pressure in the main storage chamber 13 of the compressed air storage tank 14 rises to the predetermined upper limit pressure value P1, the pressure is transferred to the governor 17 via the piping 1G.
The information is roughly transmitted from the governor 17 to the unloader and discharge valve 22 of the air compressor 1, disabling the operation of the air compressor 1, stopping the delivery of compressed air, and disabling the discharge valve 22. opens.

Then, the compressed air in the dryer 3 passes through the discharge valve 22 and is discharged from the discharge pipe 49 at once, and the water accumulated in the inner bottom of the dryer 3 is discharged to the outside at the same time. Thereafter, as the pressure in the dryer 3 decreases, the dry compressed air in the pipe 7 flows back toward the discharge valve 22 and flows into the dryer 3, and the valve element 40 of the valve 45, which is open, and valve seat 43
Through a relatively narrow passage between the distribution 11! ? 9 and the dry compressed air in the regeneration lamp chamber 10 of the compressed air storage tank 14 gradually flows into the dryer 3. As this dry compressed air flows into the dryer 53, it expands into a dry compressed air with lower humidity and is discharged through the discharge valve 22 around the desiccant. When drying, the moisture adsorbed by the desiccant is removed by the drying compressed air, and the sludge removal ability of the desiccant is restored. In this way, the desiccant]
However, the dry compressed air is not sent out from the regeneration lamp chamber 10 until the valve device 80 and the serving piston 27 move downward to close the valve 45, or until the air is discharged again. This continues until the disabled state of compression j@1 is released, whichever comes first.

When the pressure inside the main storage chamber 13 is lowered by the operation of the pneumatic actuator 6 connected to the piping 15 and reaches a predetermined lower limit pressure value, the governor 17 controls the unloader and discharge valve 22 of the air compressor 1. Exhaust the compressed air that was being supplied to
The air compressor 1 is operated to start discharging compressed air toward the compressed air storage tank 14, and the discharge valve 22 is activated.
Close the valve. Then, as described above, the dried compressed air passes through the dryer 3 and the valve device 8 to the compressed air storage tank 14.
The pressure inside the main storage chamber 13 and the regeneration lamp chamber 10 rises again.

In this way, a series of operations are repeated, and when looking at the entire pressure source device, there are two stages: a drying process in which the compressed air discharged from the air compressor 1 is dried and stored in the compressed air storage 11% 14, and a regeneration lamp chamber. 10. The regeneration step of causing dried compressed air to flow back toward the dryer 3 to regenerate the desiccant is sequentially repeated.

Here, a case will be described in which the amount of air consumed by various pneumatic actuators connected to the main storage chamber 13 via piping 15 is small in the desiccant regeneration process. In this case, valve fitting @8
From the upper chamber 33 side, the upper limit pressure P1 in the main storage chamber 13 acts constantly on the effective pressure receiving area of the small diameter portion 29 of the stepped piston 27, and the stepped piston 27 is pushed downward by the force of the p1os force. is under pressure.

On the other hand, the pressure within the regeneration storage chamber 10 acts on the effective pressure receiving area S2 of the large diameter portion 28 from the royal chamber 36 side, and the stepped piston 27 is pressed upward; Since the pressure decreases from the pressure P1 at the start of external generation as the regeneration progresses, the acting force that presses the stepped piston 27 in the direction also decreases. Therefore, if the pressure in the regeneration storage lO is P2, the pressure in the regeneration storage lO has decreased until the pressing force acting on both ends of the stepped piston 27 becomes Pl・s1=p2・S2. That is, when the pressure inside the regeneration lamp chamber 10 becomes P2=P□・S1/S2, the stepped piston 27 starts to move downward, and then P2<
When Pl.S1/S2 is reached, the stepped piston 270 moves downward, causing the valve element 40 to sit on the valve seat 43 and the valve 45 to close.

In this way, the backflow of dry air from the regeneration needle base lO to the dryer 3 @ causes the pressure inside the regeneration lamp chamber 10 to change from Pl to Pl.
・This continues until the temperature drops to S□/S2, and the movement of the dry air is cut off by closing the vent valve 45, and the compressed air in the pipe 7 and the dryer 3 passes through the discharge valve 22 and is discharged from the discharge ¥t49. Then, the desiccant regeneration process is completed.

As described above, the companding device 8 operates at a pressure P2 in the regeneration lamp chamber 10.
is a constant ratio S□/S to the upper limit pressure in the main reservoir 13
Since dry air is allowed to flow back from the regenerating needle base 10 to the dryer 3 side until the pressure is reduced to
But by users etc.! Even if the upper limit pressure in the main needle base 13 decreases due to adjustment or fluctuations in the operation of the governor 17, drying air continues to flow back according to the pressure, which is necessary for regenerating the desiccant. However, it is dangerous to run out of air. In other words, the upper limit pressure in the main needle base 13 adjusted by the governor 17 decreases by △P than the predetermined upper limit force value P□, and the pressure in the main needle base 13 and the regeneration lamp chamber 10 decreases. is (Pl-
Even if the desiccant regeneration process is started when P2≦(Pl−ΔP), the pressure within the regeneration lamp chamber 10 acting upward on the crown 36@ of the stepped piston 27 is P2≦(Pl−ΔP).
Until S□/S2, the stepped piston 27 does not move downward and the valve 45 remains open. In this way, the pressure inside the regeneration lamp chamber 10 is lower than the pressure P1·e1/F32 determined for the predetermined upper limit pressure value P (Pl−Δ
P)・S□/S2 Until the pressure is reduced to S2, dry compressed air continues to flow backwards from the regeneration needle base 10 toward the dryer 3 side by opening the valve 45, so the amount of air necessary for regenerating the desiccant can be reduced. The desiccant can be regenerated sufficiently.

In this embodiment, when the upper limit pressure in the main needle base 13 decreases by ΔP, the difference between the upper limit pressure and the valve closing pressure of the valve device 8 starts regeneration at a predetermined upper limit pressure value P1. Compared to the case, △P・(S2-S engineering)/S2 is slightly smaller i
Although the amount of dry air flowing back will also decrease slightly, the amount of air discharged from the air compressor 1, passed through the dryer 3, and degrouped will be reduced by the amount of compressed air stored in the compressed air storage chamber 14. Since it responds to the upper limit pressure of the air, the amount of dry air that flows back will change as described above, but it is not a problem and the amount of dry air necessary for regenerating the desiccant will be ensured. Ru.

According to the embodiment described above, the stepped piston 27 has the stepped piston 27 on which the pressure inside the regeneration lamp chamber 10 acts on the end face of the large diameter part 28 and the pressure inside the main needle hub 13 on the end face of the small diameter part 29, and this service piston. Valve device 8 provided with a valve 45 that closes due to the downward movement of 27
is connected between the dryer 3 and the regeneration needle base 10, so that the pressure within the regeneration lamp chamber 10 is maintained at a constant rate compared to the pressure within the main needle base 13, and the tb small diameter portion 29 and Dry air is allowed to move from the regeneration needle base 10 to the dryer 3 (llll) until the pressure is reduced to the effective pressure receiving area ratio S□/s2 with the large diameter portion 28. Therefore, the main needle base 13 Even if the internal pressure fluctuates, the valve device 8 operates according to the pressure and the dry air continues to move, so the amount of dry air necessary for regenerating the desiccant can always be obtained, and the regeneration of the desiccant In addition, the valve f! element 40 is movable relative to the stepped piston 27, and the stepped piston 27 moves toward the lower chamber 36, causing the valve element 40 to open. When the user is seated on the seat 43 11, the valve 45 acts as a check valve that prohibits air movement from the regeneration needle base 1o side to the dryer 3 side. A check valve provided between the valve element 4o and the valve seat 43 can be omitted.In the embodiment, it is assumed that a throttle passage is formed between the valve element 4o and the valve seat 43 when the valve 45 is open. However, in a normal case, a throttle passage is provided near the outlet 6 inside the dryer 3, so in such a case, it is not necessary to form a throttle passage by the valve element 40 and the valve seat 43. .

The present invention provides an upper chamber 33 instead of the stepped piston 270 described above.
A piston having an equal effective pressure receiving area on the lower chamber 36 side is disposed in the cylinder hole, and the piston is placed in the upper chamber 33 side.
B1111 A spring may be provided to bias the FC.

In this case, if the effective pressure receiving area of the piston is 81 and the biasing force of the spring is F, then when the relationship between the pressing forces acting on both ends of the piston is PIS≧P2S0F, that is, when the regeneration needle base When the pressure inside 10 becomes P2≦P□-F/S, the piston moves downward and the valve 45 closes. As a result, the regeneration needle base 1 is heated until the pressure inside the regeneration needle base 10 decreases by a constant pressure y/s compared to the pressure inside the main needle chamber 13.
Since dry air is allowed to move from zero to the dryer 3 side, even if the upper limit pressure in the main needle chamber 13 fluctuates, the amount of dry air necessary for regenerating the desiccant can always be obtained. The agent can be regenerated sufficiently. Furthermore, the same effect can be obtained by using a diaphragm instead of the piston described above. In addition, in the illustrated embodiment, the L valve device [8 is interposed in the middle of the piping between the dryer 3 and the regenerating needle base 10, but it may also be attached integrally to the dryer 3 or the compressed air storage tank 14. It may also be incorporated. As described above, the present invention is not limited to the embodiment shown in the drawings, and there is a gap between the desiccant and the regenerating needle base so that the pressure in the raw storage chamber is constant with respect to the pressure in the main needle chamber. It is only necessary to provide a valve device that allows drying air to move from the regenerating needle base to the desiccant until the ratio or a certain value decreases.

It goes without saying that the effective pressure ir+i product of the stepped piston, the biasing force of the spring, etc. may be set as appropriate depending on the usability of the pressure source device.

As is clear from the above description, the present invention provides a structure in which the pressure in the regeneration storage tank is lowered to a pressure determined by a predetermined relationship compared to the pressure in the storage tank between the desiccant and the regeneration storage tank. By installing a valve device that allows air to move from the 111 raw storage tank to the desiccant, even if the upper limit pressure in the storage tank fluctuates, air can be moved from the regeneration storage tank to the desiccant. Since the air necessary and sufficient for regenerating the desiccant can be moved, it is possible to provide a pressure source device for a pneumatic circuit that can sufficiently regenerate the desiccant.

[Brief explanation of drawings]

The drawing is a schematic diagram of an embodiment of the invention, showing a valve device in cross section. l... Air compressor 3... Drying z: 48... Valve device lO... Regeneration needle point 13... Main wheelhouse j4...
Compressed air storage tank 17... Governor 22... Discharge valve
27...Stepped piston 45...Valve

Claims (1)

[Claims] an air compressor that discharges compressed air; a storage tank that stores air discharged from the air compressor; a dryer disposed between the storage tank and the air compressor and containing a desiccant; a regeneration storage tank that is disposed between the storage tank and stores regeneration air;
an exhaust valve that connects the air compressor side of the desiccant to the outside air in response to an external command; and an exhaust valve that connects the air compressor side of the desiccant to the outside air in response to an external command; In the pressure source device for a pneumatic circuit, the pressure source device for a pneumatic circuit is provided with an operation adjustment mechanism that disables the discharge valve and issues a command to the discharge valve. A pressure source device for a pneumatic circuit, comprising a valve device for allowing movement of air from the regeneration storage tank toward the desiccant until the pressure decreases to a pressure determined according to a predetermined relationship compared to the pressure within the regeneration tank.