JPS64992Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air dryer with an internal residual pressure valve installed between a compressed air source and pneumatic equipment.

[Conventional technology]

FIG. 1 shows a conventional air dryer incorporated in a vehicle height adjustment device, and the air dryer 1 is provided between an air compressor 2 and an air leveler 3,
A switching valve 4 is provided on the air compressor 2 side of the air dryer 1.
is provided.

In the figure, 5 is a dryer case (hereinafter referred to as case) of the air dryer 1, and the case 5 is made of a bottomed cylindrical body having a flange 5A on the outside of the opening.
A vent hole 6 connected to the air compressor 2 is formed in the center of the bottom portion 5B. Reference numeral 7 denotes a lid attached to the opening of the case 5, and the lid 7 has a protrusion 7A at the center of the outside and a recess 7B at the center of the inside of the protrusion 7A.
A sleeve 7C that fits into the opening of the case 5 is provided on the opposite side of the protrusion 7A, and a flange 7D that abuts against the flange 5A is provided on the outside of the starting end of the sleeve 7C. It is being A vent 8 connected to the air levelizer 3 is formed at the center of the protrusion 7A, and the vent 8 opens into the recess 7B.

Reference numeral 9 designates an orifice plate fitted into the recessed portion 7B, and reference numeral 10 designates a small diameter orifice formed in the orifice plate 9. The orifice 10 communicates with the vent 8 and has the function of reducing the pressure within the case 5 of the compressed air flowing from the air leveler 3 through the vent 8.

Reference numeral 11 denotes an adsorption chamber located in the case 5 on the side of the vent 6, and the adsorption chamber 11 is formed by two perforated plates 1.
2, 13, each perforated plate 12, 13
Filter elements 14 and 15, which are made of, for example, a fibrous material and have the function of adhering moisture in compressed air, are attached to opposing surfaces of the filter elements. Reference numeral 16 denotes an adsorbent filled in the adsorption chamber 11. The adsorbent 16 is, for example, silica gel, and has the function of adsorbing moisture in compressed air and drying the compressed air.

17 is an air dryer 1 located on the side of the vent 8 in order to keep the residual pressure inside the air levelizer 3 above a predetermined value.
The residual pressure valve 17 has a valve seat member 18, and the valve seat member 18 is attached to the sleeve 7 of the lid 7.
It consists of a flange part 18A that is locked at the tip of C, a cylindrical part 18B that has a smaller diameter than the flange part 18A and extends toward the vent 8 side, and a valve seat part 18C formed at the bottom of the cylindrical part 18B, The valve seat member 18
It is divided into an expansion chamber A on the side of the vent 8 and a spring chamber B on the side of the adsorption chamber 11. A return side ventilation hole 19 is formed at the axial center position of the valve seat portion 18C, and a plurality of supply side ventilation holes 20 are also formed around the ventilation hole 19. Reference numeral 21 denotes a residual pressure valve body located within the cylindrical portion 18B of the valve seat member 18 and seated on and off the seat portion 18D formed at the open end of the vent hole 19. The valve body 21 has a disk-shaped spring receiver. A member 22 is fixed to the spring receiving member 22, and a plurality of ventilation holes 23 are formed in the spring receiving member 22. Reference numeral 24 denotes a spring tensioned between the spring receiving member 22 and a spring seat 25 provided on the opening side of the cylindrical portion 18B. The valve is closed and can be opened by compressed air from the vent 8.
Furthermore, 26 is a check valve body made of an elastic body such as rubber, and the center portion of the check valve body 26 is connected to the valve seat portion 1.
8C, located on the side of the vent hole 8, and its peripheral edge becomes a free end, so that it normally closes the vent hole 20 and can be opened by compressed air from the vent hole 20. . Thus, the residual pressure valve 17 is composed of the valve seat member 18, the vent holes 20, 23, the residual pressure valve body 21, the spring bearing member 22, the spring seat 25, and the check valve body 26.

27 is a spring stretched between the outer surface of the flange 18A of the valve seat member 18 and the perforated plate 13;
5 is constantly pressed in the direction of the bottom 5B, and the suction chamber 1
The adsorbent 16 in 1 is kept in a dense state.

The air dryer 1 according to the prior art has the above-mentioned configuration, and its function will be explained based on FIG. 1. When raising the vehicle height, the switching valve 4 is closed and the compressed air from the air compressor 2 is The air is introduced into the air dryer 1, where the filter elements 14 and 15 adsorb moisture, and the adsorbent 16 adsorbs and dries the remaining moisture, and then the check valve body is passed through the ventilation holes 23 and 20 constituting the residual pressure valve 17. 26 is opened and the air is supplied to the leveler 3 through the orifice 10 to adjust the vehicle height. At this time, since water in the compressed air is removed by the adsorbent 16, it is possible to prevent functional deterioration caused by accumulation of water droplets in the air levelizer 3.

Conversely, when lowering the vehicle height, when the switching valve 4 is opened, the compressed air from the air levelizer 3 passes through the vent 8 and is reduced to near atmospheric pressure by the orifice 10. After being discharged into the expansion chamber A formed between the valve seat member 18 and the valve seat member 18, the residual pressure valve body 21 is opened against the spring 24 through the ventilation hole 19, and the residual pressure valve body 21 is opened to flow into the adsorption chamber 11 side. In the adsorption chamber 11, while the dry compressed air from the air levelizer 3 is passed through the adsorption chamber 11, the adsorbent 16 and the filter element 14,
The adsorbent 16 absorbs the moisture adsorbed on the adsorbent 15.
And the filter elements 14, 15 are regenerated. In addition, the flow rate of compressed air discharged from the air levelizer 3 is determined by the orifice 10 and the residual pressure valve 17.
The vehicle body (not shown) supported by the air levelizer 3 can gradually descend, and the residual pressure valve 17 is regulated by the spring 24.
Since the seat portion 18D is biased by the switch valve 4, the residual pressure inside the air levelizer 3 can be maintained at a predetermined value or higher even if the switching valve 4 remains open.

[Problem that the invention attempts to solve]

However, the air dryer 1 according to the prior art described above
Since the orifice 10 was located between the air levelizer 3 and the residual pressure valve 17, the following problem occurred. That is, when compressed air from the air levelizer 3 flows into the expansion chamber A, which is in a state where the pressure is approximately equal to atmospheric pressure, through the orifice 10,
The compressed air rapidly expands in volume within the expansion chamber A. As a result, the flow rate of the compressed air flowing through the vent hole 8 increases, and the flow rate of the compressed air flowing through the vent hole 19 increases. The compressed air accelerated in this way flows to the residual pressure valve 1.
In order to flow to the adsorption chamber 11 side through the ventilation hole 19 of
Not only are the residual pressure valve 17 itself vibrated, but the residual pressure valve 17 itself generates self-excited vibration and generates abnormal noise, which has the drawback of causing noise. Further, since the spring 24 is largely bent, the life of the spring 24 is shortened, and the function of the residual pressure valve 17 is also degraded. Furthermore, since the prior art is provided with the orifice 10 located upstream of the vent hole 19, the pressure is reduced only by the orifice 10, and the orifice diameter must be extremely small to achieve sufficient pressure reduction. However, there is a problem in that the responsiveness of vehicle height adjustment is poor.

The present invention was proposed to solve the above-mentioned drawbacks of the conventional air dryer, and when the compressed air in the pneumatic equipment is discharged into the adsorption chamber through the residual pressure valve, the air dryer is compressed before being expanded by the orifice. To provide an air dryer which can prevent the generation of noise by opening a residual pressure valve with air and can improve the responsiveness of pneumatic equipment.

[Means for solving problems]

To achieve the above object, the present invention provides a dryer case which is made of a cylindrical body and has one vent port connected to a compressed air source and another vent port connected to a pneumatic equipment; an adsorption chamber defined within the case via a filter element and filled with an adsorbent; A valve seat member that defines chamber A located on the vent side and chamber B located on the adsorption chamber side, and a return side vent from the pneumatic equipment bored in the valve seat member to the pneumatic equipment. and a supply side ventilation hole located on the side of the chamber B so as to be seated on and off the valve seat member, and the supply side ventilation hole is provided so as to be placed on and off from the valve seat member, and the air flow from the chamber A to the chamber B is provided through the return side ventilation hole.
a residual pressure valve body that allows compressed air to flow only to the side and maintains the residual pressure in the pneumatic equipment at a predetermined pressure; and a residual pressure valve body that is located on the chamber A side and is provided so as to be seated on and off the valve seat member; The chamber B via the supply side vent
In the air dryer, the valve seat member includes an orifice plate located on the chamber B side between the residual pressure valve body and the adsorption chamber. , the orifice plate is provided with an orifice for reducing the pressure of the compressed air flowing out from the residual pressure valve, and the orifice is formed to have a smaller diameter than the return side ventilation hole.

Since the present invention is configured in this manner, when compressed air from the pneumatic equipment is returned to the air dryer side, the residual pressure valve is closed by the return side compressed air acting on the residual pressure valve element through the return side vent. When the valve is opened and the compressed air flowing out from the residual pressure valve body passes through the orifice, the pressure is reduced, and the chamber A becomes an expansion chamber, and low-pressure compressed air is supplied to the adsorption chamber. As a result, compressed air with a slow flow rate before pressure reduction flows through the residual pressure valve body, so the valve body and valve seat members do not vibrate, and the residual pressure valve body itself causes self-excited vibration, which may cause abnormal noise. Therefore, the valve operation can be prevented from being obstructed, and a low-noise air dryer can be achieved. Moreover, since the compressed air flowing into the adsorption chamber from the pneumatic equipment side is depressurized by the return side vent and the orifice, the diameter of the orifice can be increased.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, the same components as those shown in FIG. 1 are given the same reference numerals, and their explanations will be omitted. In this embodiment, the orifice plate 9 is located in the concave portion 7B of the lid 7, and the orifice plate 9 is located in the cylindrical portion 18 of the valve seat member 18.
No spring seat 25 for the spring 24 is provided in B.

However, 31 is an orifice plate used in this embodiment, and the orifice plate 31 has an orifice 32 smaller in diameter than the return side ventilation hole 19 formed therein. The orifice plate 31 is fixed to a stepped portion 18E formed at the open end of the cylindrical portion 18B that constitutes a portion of the valve seat member 18 of the residual pressure valve 17. In addition,
The orifice plate 31 also serves as one spring seat for the spring 24 of the residual pressure valve 17. Therefore, in this embodiment, chamber A does not serve as an expansion chamber, but spring chamber B serves as an expansion chamber.

This embodiment is configured as described above, but when raising the vehicle height, the switching valve 4 is closed to guide the compressed air from the air compressor 2 into the air dryer 1 and into the adsorption chamber 11. After absorbing and drying moisture, the air is guided through the orifice 32 to the residual pressure valve 17, the check valve body 26 is opened, and the air is supplied to the air leveler 3 through the vent 8.

Conversely, when lowering the vehicle height, when the switching valve 4 is opened, the compressed air from the air levelizer 3 is released into the chamber A through the vent 8, and the compressed air remains compressed and is not accelerated in any way. Air is valve seat member 1
8, the residual pressure valve body 21 is opened against the spring 24, and after passing through the vent hole 19, the pressure is slightly reduced, and then the inside of the cylindrical portion 18B is released. is discharged into the orifice 32.
Regeneration is performed while the air, which has been greatly reduced in pressure and expanded in volume, flows through the adsorption chamber 11.

However, in this embodiment, the compressed air after passing through the return side vent 19 of the residual pressure valve 17 flows through the orifice 32 and is depressurized, so the residual pressure valve 17 does not allow the compressed air to remain in a high pressure state. Therefore, the residual pressure valve body 21 can be opened and closed as in the prior art.
Since the spring 24 does not cause self-excited vibration or fatigue of the spring 24, a low-noise air dryer can be achieved, and its life can be extended.

Moreover, since a predetermined load is applied to the residual pressure valve body 21 in the valve closing direction by the spring 24, even when the residual pressure valve body 21 opens and the compressed air passes through the return side ventilation hole 19, there is a slight After that, while the compressed air passes through the orifice 32, the pressure is greatly reduced. Therefore, as a result, a two-stage depressurizing action is performed, and the orifice diameter can be made larger than that of the orifice 10 of the prior art. As a result, compressed air can be supplied to and discharged from the air levelizer 3 in a short time, and the responsiveness of vehicle height adjustment can be improved.

[Effect of idea]

As described in detail above, according to the present invention, the compressed air from the pneumatic equipment is configured to pass through the residual pressure valve body in a high pressure state without being reduced in pressure, and then to be depressurized by the orifice and guided to the adsorption chamber. Therefore, not only the valve body of the residual pressure valve body but also the valve seat member, pressure setting spring, etc. are prevented from vibrating due to compressed air.
The residual pressure valve body itself does not cause self-excited vibration and generate abnormal noise, and a low-noise air dryer can be achieved. Moreover, after a slight pressure reduction effect is performed when the residual pressure valve body opens, the orifice performs a large pressure reduction effect, so it is necessary to increase the diameter of the orifice to obtain the same pressure reduction effect. It is possible to improve the responsiveness of pneumatic equipment.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an air dryer according to the prior art, and FIG. 2 is a longitudinal sectional view of an air dryer according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Air dryer, 2... Compressed air source, 3... Pneumatic equipment, 11... Adsorption chamber, 17... Residual pressure valve, 31... Orifice plate, 32... Orifice.

Claims (1)

[Scope of utility model registration request] a dryer case made of a cylindrical body and having one vent port connected to a compressed air source and another vent port connected to a pneumatic device; defined within the dryer case via a filter element; an adsorption chamber filled with an adsorbent; a chamber A provided in the dryer case located closer to the other vent than the adsorption chamber; and a chamber A located closer to the other vent; a valve seat member defined in a chamber B located in the chamber B; a return vent hole from the pneumatic equipment and a supply vent hole to the pneumatic equipment provided in the valve seat member; The valve seat member is located so as to be seated on and off the valve seat member, and allows compressed air to flow only from the chamber A to the chamber B side through the return side ventilation hole, and maintains a predetermined residual pressure in the pneumatic equipment. a residual pressure valve body located on the chamber A side and seated on and off the valve seat member, and configured to supply compressed air only from the chamber B to the chamber A side through the supply side ventilation hole. In an air dryer comprising a check valve body that allows flow, an orifice plate is provided on the valve seat member and located on the chamber B side between the residual pressure valve body and the adsorption chamber; 1. An air dryer characterized in that an orifice is provided to reduce the pressure of compressed air flowing out from the air dryer, and the orifice is formed to have a smaller diameter than the return side ventilation hole.