JPS6087831A - Air drying apparatus - Google Patents

Abstract

PURPOSE:To perform regeneration of drying agent securely before the agent is saturated with water by connecting an air drying apparatus selectively to a suction pipe for air of an internal combustion engine and removing the contained water in the drying agent with negative pressure of the air suction pipe. CONSTITUTION:A port (b) of a solenoid valve 20 connected to an air drying apparatus 11 is connected to an air compressor 22, and a port (C) is connected to an air suction pipe 24 of an internal combustion engine 23 such as a motor- car engine on which the air-drying apparatus is loaded. At the starting operation of the engine, the port (a) is connected to the port (c) by the instruction given to the solenoid valve 20. In an idling state of the engine 23, a throttle valve 25 is closed completely and the air suction pipe 24 is in a negative pressure condition by the vacuum generated by the engine 23, thus the drying apparatus sucks air through a pipe 12. At the same time, heat generating current is fed to a heating element 28 comprising a PTC element to heat the drying agent 15. Thus, the water contained in the drying agent 15 is evaporated and sent to the engine 23 through the ports (a) and (c). Therefore, regeneration of the drying agent 15 is always performed at the starting stage of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air drying device used in an apparatus including an internal combustion engine, which removes moisture contained in compressed air for performing remote control, automatic operation, etc. using compressed air. .

The working air used in devices that utilize compressed air pressure or compressed air flow is always in a humid state containing a large amount of water.

If air containing a lot of moisture is used for air-utilizing equipment, it may cause various damage to the equipment, so please dry the air thoroughly before using it. , it is necessary to ensure that the air utilization is supplied to the meter. For this reason, for example, a dryer using a moisture-absorbing desiccant such as silica gel is installed in the piping for the air-utilizing unit.

In other words, a dryer consisting of a sealed container filled with desiccant is interposed between the compressor and the air-utilizing equipment without producing compressed air, and moisture in the air sent from the compressor to the air-utilizing equipment is removed. It is something to do.

However, the desiccant used here, such as silinocogel,
The saturated amount of water is determined by the weight of the silica gel, and when the silica gel absorbs water to the point of saturation, no more water can be removed from the circulating air. Therefore, in such a state, a large amount of water is sent to the air utilization equipment together with compressed air. Therefore, it is necessary to replace the desiccant when or before the amount of water contained in the desiccant reaches a saturated state. However, the determination of the saturation state of the desiccant has conventionally been determined based on experience and intuition, which makes it difficult to reliably manage and maintain the drying device.

This invention was made in view of the above points, and in particular, it is possible to automatically absorb moisture from the desiccant used, thereby eliminating the need for maintenance work such as replacing the desiccant. Therefore, it is an object of the present invention to provide an air drying device for use in an apparatus including an internal combustion engine, which ensures that dry air is constantly and reliably supplied to air utilization equipment.

That is, the air drying device according to the present invention is configured such that a dryer, which is a container filled with a desiccant and is interposed between a compressor and an air utilization device, is selectively coupled to an intake pipe of an internal combustion engine. , the moisture contained in the desiccant is removed by drawing air into the dryer using negative pressure in the suction pipe. Further, a heat generating mechanism is set in the dryer, and the heat generating mechanism is controlled to generate heat at the same time as the negative pressure is set.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the air dryer 11. The air dryer 11 includes a sealed container 14 having pipes 12 and 13 serving as an inlet and an outlet, and a desiccant 15 such as silica gel is contained inside the container 14. Filled. Here, inside the container 14 corresponding to the pipes 12 and 13, filters 18 and 19 are set by filter holders 1G and 17 each having a large number of ventilation holes.

A solenoid valve 20 is installed in the piping 12 of such an air dryer 11.
This solenoid valve 20 has a port a connected to the piping 12, and ports b and C that are switched and connected to the boat a.
0 is a 3-boat 2 that selectively connects port a to port b or c according to a command signal from a control circuit 21.
Consists of a position solenoid valve. In this case, in a normal state where no signal is given from the control circuit 21, the baud 1-
A state is set in which baud 1-a is connected to baud 1-b, and baud 1-a is set to be connected to baud 1-G when a command is given from the control circuit 21.

Boat b of this solenoid valve 20 is connected to an air compressor 22 that generates compressed air, and boat C
is connected to an intake pipe 24 of an engine 23, which is a power engine of an automobile, on which this drying device is mounted, for example. In this case, the bow 1-c is the engine 2 of the throttle valve 25.
It is connected to the intake pipe 24 on the third side, and is set so that negative pressure is effectively applied to the boat C in an idling state when the throttle valve 25 is closed. Although not particularly shown in the drawings, the air compressor 22 is driven by an engine 23.

The piping 13 of the dryer 11 communicates via a check valve 26 with an air utilization mechanism 27 that utilizes compressed air pressure or compressed air flow, and this air utilization mechanism 27 is controlled by the control circuit 21. It is something that

Here, inside the container 14 of the dryer 11, a heating element 28 made of, for example, a honeycomb-structured PTC element with a large number of ventilation holes is set so as to be embedded in the desiccant 15. The heating element 28 is connected to a wiring 30 that is connected to the control circuit 21 via a bushing 29 that penetrates the container 14, and a heating current is supplied according to a command from the control circuit 21.

Here, the control circuit 21 is constituted by a microcomputer that electronically controls, for example, the fuel injection amount of the engine 23, and when the key switch 31 is operated, power is supplied from the battery 32 to control the engine 23. In addition to controlling the drive, an operation command is given to the solenoid valve 20 within a specified time range from when the switch 31 is turned on, and the baud 1-a is connected to the baud 1-C. At the same time, a heating current is supplied to the heating element 28 during the specified time range.

That is, this control 11 circuit 21 incorporates means for controlling the air compressor 22, means for controlling the heating current to the air dryer 11, and means for controlling the air utilization mechanism 27. .

That is, in the drying device configured as described above,
In a normal operating state, the solenoid valve 2o is in a state of connecting ports ta and b, and the air compressor 22 is operated to send compressed air to the dryer 11. In this state, the air sent into the dryer 11 contains a large amount of moisture. Moisture contained in the compressed air thus sent is absorbed by the desiccant 15, and dry air containing no moisture is supplied to the air utilization mechanism 27. If used continuously for a long period of time in such conditions, the moisture absorbent 1
The amount of moisture in the moisture absorbent 15 increases and exceeds the moisture absorption capacity of the moisture absorbent 15.

However, in the above device, the desiccant 1 is
This device controls the water content of the engine 23 by giving a command to the solenoid valve 20 in response to the turning-on operation of the key switch 31 that controls the start of this device, and connecting the boat a to the boat C to control the intake air of the engine 23. The negative pressure generated in the tube 24 is applied to the dryer 11.

In this state, the engine 23 is in a starting state, and the throttle valve 25 is in a fully open state in an idling state. Therefore, the intake pipe 24 is in a large negative pressure state due to the high vacuum generated by the engine 23, and the dryer 11 is in a state where air is taken in from the pipe 12. In this case, the check valve 26 prevents air from flowing in from the direction of the pipe 13, so the desiccant 15 in the container 14 of the dryer 11 is exposed to vacuum, and the moisture contained in the desiccant 15 is Steamed. The engine is then sent to the engine 23 via boats a and C.

At this time, a heating current is simultaneously supplied from the control circuit 21 to the heating element 28, the desiccant 15 is heated, and the moisture contained in the desiccant 15 is evaporated more effectively.

Here, since this heating element 28 is made of a material having so-called PTC characteristics, it has a positive humidity characteristic in which the electric resistance changes depending on the temperature of the U ramic itself that constitutes this heating element 28. 6'rJ, that is, when the temperature rises and exceeds the decure point, its resistance increases rapidly, and when the current is applied directly, the temperature of the heating element 28 rises rapidly, and its temperature reaches the decure point. When the value exceeds 1, the electrical resistance increases and the concentration of the heating element 28 is kept constant from then on. A normal PTC element reaches its cue point temperature in a few seconds.

The boiling point of the water contained in the desiccant 15 is 100 at atmospheric pressure.
℃, but when the inside of the container 14 of the dryer 11 is in a state where air is sucked by the negative pressure of the engine 23, the desiccant 15
The atmospheric pressure in the area decreases, and the boiling point of the water contained in the desiccant 15 decreases. For example, the absolute pressure no.j is about 260
mmHo abs, (gauge pressure -50On+mHI
JG), the boiling point of water is about 72.5°C, so it is effective to make the Curie point of the heating element 28 72.5°C or higher. Generally, PTC heating elements with a heating point of about 120°C to 150°C are easily available, and the photothermal element 28 has a heating point of 1.
A 20'C PTC exothermic agent may be used.

However, immediately after the start control of the engine 23, the dryer 1
The moisture absorption operation of the desiccant 15 of No. 1 is started, and this moisture absorption operation is performed when the engine 23 is idling after starting, and ends before a normal start operation is performed. Therefore, in the control circuit 21, the completion time of this moisture absorption operation is set, and control is performed such that the command to the solenoid valve 20 is cut off after the elapse of that time after the key switch 31 is turned on. b, connect the dryer 11 to the near compressor 22, and connect the air utilization mechanism 2.
7, the state shifts to a compressed air usage state in which compressed and dried air is sent.

That is, when the engine 23 is started, the desiccant 15 of the air dryer 11 always absorbs moisture, and the desiccant 15 is reliably prevented from containing moisture up to the saturation point. It is something that can be done. Especially in this moisture absorption action poem of the desiccant 15, the heating element 2
By heating the desiccant 15 by 8, a more effective moisture absorption operation can be performed.

Incidentally, the evaporated moisture during the moisture absorption operation of the desiccant 15 is as follows:
This moisture is taken into the engine 23, but because of the large amount of heat generated by the engine 23, this moisture is decomposed or released into the atmosphere without any adverse effects.

In the above embodiment, in order to remove moisture from the desiccant 15,
In addition to negative pressure from the engine 23, a heating operation by the heating element 28 was also performed. However, the effect can also be achieved by only a suction operation using negative pressure without using a heating operation in particular. In this case, it is necessary to lengthen the suction operation time.

Figure 2 shows the other *male side of the dryer section 11, connecting the pipes 12 and 13, which serve as air intake and outlet, to the container 1.
These are set side by side on one side of 4.

In this case, the separator 33 may be provided by separating the pipes 12 and 13 and forming a passage on the side opposite to the surface having the pipes 12 and 13. Further, if a space is set between the separator 33 and the container 14 on both sides thereof, air circulation between the pipes 12 and 13 will be improved. Further, the heating element 28 in this case may be set at a position facing the tip of the separator 33, and in this case, as is clear from the figure, the structure is not such that air passes through the photothermal element 28. Therefore, there is no need for the heating element 28 to have a honeycomb structure.

In the above embodiment, it has been explained that PTC material is used as the heating element, but this may of course be constructed with an electric heater using nichrome wire, or it may be constructed so that the temperature is controlled using a heat sensitive mechanism. It's good.

In addition, in the embodiment, when the key switch 31 is operated, the desiccant 1 is
5, the dehumidifying operation is performed at any time (however, the air utilization mechanism 27
It may also be possible to automatically control the non-operating FR) to perform the desiccant dehumidification operation.

Further, the desiccant used here is not limited to silica gel, but also a desiccant having a moisture absorbing effect, such as activated alumina, etc., can be effectively used. In addition, there are 3 solenoid valves that switch the air passage between when a normal air compressor operates and when the desiccant absorbs moisture.
Although a single boat with two positions is shown, one or a combination of other solenoid valves, manual valves, switches, etc. may be used.

As described above, according to the present invention, an air drying device is provided which removes moisture from compressed air supplied to an air utilization mechanism and ensures that dry air is used. The desiccant that dries the air is reliably controlled to remove moisture before the moisture content reaches a saturated state, and the dry state of the compressed air used in the air utilization mechanism is ensured in a good manner.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining an air drying apparatus according to one embodiment of the present invention, and FIG. 2 is a sectional view of a dryer section for explaining another embodiment of the present invention. DESCRIPTION OF SYMBOLS 11... Dryer, 14... Container, 15... Desiccant, 20... Solenoid valve, 21... Control circuit, 22...
Air compressor, 23...engine, 24...
Intake pipe, 27...Air utilization mechanism, 28...Heating element. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) An air dryer that houses a moisture absorption drying mechanism inside, a compressor that sends compressed air to the air dryer, an air utilization mechanism that guides the compressed air that has passed through the air dryer, and the air dryer. and an internal combustion engine to which an intake pipe is selectively connected to the air dryer, and the inside of the air dryer is selectively set to a low atmospheric pressure state by the negative pressure of the intake pipe generated during operation of the internal combustion engine. An air drying device characterized by: (2) The moisture absorption drying mechanism housed in the air dryer is constituted by a desiccant and a heat generating device t14M, and the heat generating mechanism is controlled to generate heat when the negative pressure is applied. Air drying equipment as described in Section.