JP2013186762A - Pressure-reducing valve, air tool having pressure-reducing valve and air compressor having pressure-reducing valve - Google Patents

Abstract

【Task】
Provided are an air tool and an air compressor in which generation of sound due to vibration of a spring of a pressure reducing valve is reduced.
[Means for Solving the Problems]
The object is to provide a housing having an air passage communicating between the primary pressure side and the secondary pressure side, a piston movably provided in the housing, a spring for pressing the piston, and a piston as the piston moves. And a valve body that opens and closes the air passage, and that automatically opens and closes the flow path between the primary pressure side and the secondary pressure side according to a pressure difference. This is achieved by a pressure reducing valve or an air tool or an air compressor having the pressure reducing valve, wherein an elastic body is disposed between or between the spring and the piston.
[Selection] Figure 2

Description

The present invention relates to a pressure reducing valve for compressed air, an air tool having a pressure reducing valve, and an air compressor having a pressure reducing valve.

  An air tool such as a nail driver using a compressed air generated by an air compressor as a power source is known. When driving the pneumatic tool with compressed air, a pressure reducing valve is used to reduce the compressed air to an optimum pressure.

  The structure of a conventional pressure reducing valve will be described with reference to FIG. The pressure reducing valve includes a piston, a spring that presses the piston toward the air intake side (primary pressure side), a valve body that moves with the piston as the piston moves, a spring that supports the valve body in a movable manner, and a piston and valve body. A separator having an opening and closing hole that is opened and closed by a valve body, a secondary pressure chamber that accumulates compressed air (secondary pressure) that has passed through the opening and closing hole, a discharge passage that discharges the secondary pressure, a body and a piston Is formed by a pressure reducing valve inner chamber that houses an adjustment spring. The inner chamber is in communication with the atmosphere.

When the primary pressure is not supplied, the valve element is moved to the primary pressure side by the pressing force of the adjusting spring via the piston and is opened. When the primary pressure is supplied, it passes through the opening / closing hole, flows into the secondary pressure chamber, and the secondary pressure chamber gradually rises. The secondary pressure chamber faces the piston, and as the secondary pressure increases, the piston moves to a position that balances with the adjustment spring. When the valve body also moves in conjunction with the piston and the valve body hits the separator and closes the air passage 17, the inflow of compressed air into the secondary pressure chamber stops and the secondary pressure stops rising. Thereafter, when the pressure in the secondary pressure chamber decreases, the load of the adjustment spring again exceeds the load due to the secondary pressure, so that the piston and the valve body move to the primary pressure side, and the opening / closing hole is opened. This is a structure in which a predetermined secondary pressure is obtained by repeating this operation.
Japanese Utility Model Publication No. 60-107492

  As described above, the piston repeats the operation according to the change in the secondary pressure. At this time, the piston is vibrated due to sliding with the housing, fluctuation of the secondary pressure, vibration due to the primary pressure, and vibration of the valve body. This excitation force is transmitted to the adjustment spring pushing the piston, causing the adjustment spring to vibrate. At this time, a sound may be generated from the spring.

  The object is to provide a housing having an air passage communicating between the primary pressure side and the secondary pressure side, a piston movably provided in the housing, a spring for pressing the piston, and a piston as the piston moves. And a valve body that opens and closes the air passage, and that automatically opens and closes the flow path between the primary pressure side and the secondary pressure side according to a pressure difference. This is achieved by a pressure reducing valve or an air tool or an air compressor having the pressure reducing valve, wherein an elastic body is disposed between or between the spring and the piston.

  According to the above-described structure, the vibration during the piston operation is transmitted to the spring, and even when the spring is vibrated, the vibration of the spring is attenuated by the friction between the spring and the elastic body, and the generation of sound can be reduced. In addition, the elastic body provided in the valve seat attenuates the vibration of the spring and can reduce the generation of sound.

  A pneumatic tool according to a first embodiment of the present invention will be described with reference to FIG. The nailing machine shown in FIG. 1 corresponds to the pneumatic tool of the present invention, and mainly comprises a main body 1, a pressure reducing valve 2, an injection unit 3, a magazine 4, and a trigger 5. The magazine 4 accommodates the stopper and supplies the stopper to the injection unit 3. When the operator operates the trigger 5 in a state where the injection unit 3 is pressed against a material to be driven such as wood, the stopper supplied to the injection unit 3 is built in the main body 1 and is driven by compressed air. It is struck by the striking mechanism and is struck into the workpiece.

  A part of the main body 1 forms a handle for an operator to hold, and the inside of the handle forms a pressure accumulating chamber for accumulating compressed air. A pressure reducing valve 2 is provided at the end of the handle, the primary pressure side of the pressure reducing valve 2 is connected to an air compressor (not shown), and the secondary pressure side of the pressure reducing valve 2 communicates with a pressure accumulating chamber.

  The structure of the pressure reducing valve in this embodiment will be described in detail with reference to FIG. The pressure reducing valve 2 includes a housing 6 having an air passage 17 that mainly communicates a primary pressure side and a secondary pressure side, a piston 7 that is movably provided inside the housing 6, a spring 8 that presses the piston, It is formed from a seat packing 7A that is a valve body that moves with the piston 7 along with the movement and opens and closes the air passage.

  The housing 6 includes a main housing 6A and an adapter portion 6B that form a secondary pressure side housing, and a plug portion 6C that forms a primary pressure side housing. The main housing 6A has a hollow cylindrical shape. A part of the inner peripheral wall of the main housing 6 </ b> A protrudes inside, and a separator 16 that separates the space formed inside into the primary pressure chamber 14 and the secondary pressure chamber 15 is formed. An air passage 17 that communicates the primary pressure chamber 14 and the secondary pressure chamber 15 is formed in the center of the separator 16. The adapter portion 6B has a hollow cylindrical shape, and is fixed so that a part of the adapter portion 6B enters the secondary pressure chamber 15 of the main housing 6A. Therefore, one end of the internal space of the adapter portion 6B communicates with the secondary pressure chamber 15, and the other end is connected to the nailing machine body 1 and communicates with the pressure accumulating chamber of the nailing machine. The plug portion 6C has a hollow cylindrical shape, and is fixed so that a part of the plug portion 6C enters the primary pressure chamber 14 of the main housing 6A. One end of the internal space of the plug portion 6C is the primary pressure chamber 14. Communicating with On the other hand, the outer shape of the plug part 6C has a plug shape that can be connected to an air compressor (not shown), and forms a compressed air supply port through which compressed air is supplied from the other end of the internal space of the plug part 6C. .

  A piston 7 is movably provided on the secondary pressure chamber 15 side inside the main housing 6A. A part of the piston 7 extends in a rod shape, passes through the air passage 17, and is located in the primary pressure chamber 14. An O-ring 7B is provided between the piston 7 and the inner wall of the main housing 6A to block the secondary pressure chamber 15 from the atmosphere. Accordingly, the piston 7 applies pressure from the compressed air in the secondary pressure chamber 15 from the secondary pressure chamber 15 side (right side of the drawing in FIG. 2) toward the counter secondary pressure chamber 15 side (left side of the drawing in FIG. 2). It has a structure to receive. On the other hand, a spring 8 is provided on the side of the piston 7 opposite to the secondary pressure chamber 15. The end of the spring 8 on the secondary pressure chamber 15 side presses the piston 7, and the end of the anti-secondary pressure chamber 15 on the side is in contact with the adapter portion 6B. The piston 7 moves according to the spring pressure of the spring 8 and the pressure of the compressed air in the secondary pressure chamber 15.

  A seat packing 7A is provided on the primary pressure chamber 14 side inside the main housing 6A. The seat packing 7A is fixed to a rod-like extension portion of the piston 7, and a seat packing spring 9 is disposed at the other end. A seal surface 7 </ b> C is formed on the end surface of the sheet packing 7 </ b> A on the separator 16 side to block between the primary pressure chamber 14 and the secondary pressure chamber 15 in cooperation with the seating surface 6 </ b> D of the separator 16. Therefore, when the piston 7 moves according to the pressure on the primary pressure side and the secondary pressure side, the air passage 17 automatically opens and closes, and the compressed air on the primary pressure side is reduced to adjust the secondary pressure side to a predetermined pressure. be able to. Here, the main housing 6A and the adapter portion 6B are provided so as to be relatively movable in the axial direction, and the distance between both ends of the spring 8 can be changed by the operator operating the main housing 6A. Thereby, since the spring force of the spring 8 changes, the pressure on the secondary pressure side can be adjusted. The sheet packing 7A corresponds to the valve body in the present invention.

  An elastic body 10 is provided between the spring 8 and the adapter portion 6B. Specifically, the elastic body 10 is bonded to the outer periphery of the spring 8. When this structure is taken, the vibration can be attenuated by friction between the elastic body 10 and the adapter portion 6B.

  The elastic body 10 has an axial length of at least two turns in the axial direction of the spring 8. Thereby, since the friction by a surface contact arises between the elastic member 10 and the adapter part 6B, a vibration can be attenuate | damped effectively. If a material having a viscosity higher than that of the spring 8 is selected as the elastic body 10, the portions of the springs 8 that are adjacent in the axial direction are connected by the elastic body 10, so that the effect of damping vibration can be enhanced. . Further, the elastic body 10 is disposed at the axial center of the spring 8. Thereby, since the elastic body 10 contacts the adapter part 6B in a wide area irrespective of the expansion and contraction of the spring 8, the effect of damping the vibration is enhanced.

  More preferably, by making the size of the elastic body 10 in the radial direction larger than the gap between the spring 8 and the adapter portion 6B, the elastic body 10 and the adapter portion 6B can always be in contact with each other, thereby damping the vibration. It is possible to further enhance the effect.

  As described above, the elastic body 10 can attenuate the vibration generated in the spring 8 by using the frictional force and suppress the sound generated from the pressure reducing valve 2. In this embodiment, since the elastic body is provided on the outer periphery of the spring 8, the pressure reducing valve 2 can be assembled after combining the spring 8 and the elastic body 10 first. Therefore, the present embodiment is particularly excellent in that noise can be reduced without complicating the assembly of the pressure reducing valve 2 and without increasing the manufacturing cost.

  The material of the elastic body 10 can be appropriately selected from materials having elasticity and a coefficient of friction that generate a frictional force, such as foamed silicone rubber, to the extent that the expansion and contraction of the spring 8 is not hindered. If a member having a viscosity such as rubber is selected, vibration of the spring 8 can be reduced by utilizing both friction and viscosity.

  A first modification of the pressure reducing valve of the present invention will be described with reference to FIG. As shown in FIG. 3, the piston 7 passes through the inside of the spring 8, and the elastic body 10 is disposed between the piston 7 and the spring 8 and on the radially inner side of the spring 8. Similar to the above embodiment, the elastic body 10 is disposed at the axial center of the spring 8 and has an axial length of at least two turns. Furthermore, the radial dimension of the elastic body 10 is made larger than the gap between the spring 8 and the adapter portion 6B. Even with the structure of the first modification, the vibration generated in the spring 8 can be damped by utilizing both the viscosity and friction of the elastic body 10 itself, and the vibration generated in the spring 8 can be damped. Yes.

  A second modification and a third modification of the pressure reducing valve of the present invention will be described with reference to FIGS. In the second modification, the elastic body 10 is provided between the end of the spring 8 on the adapter part 6B side and the adapter part 6B. In the third modification, the elastic body 10 is provided between the end of the spring 8 on the piston 7 side and the piston 7. That is, in these modified examples, the elastic body 10 is disposed at the axial end of the spring. According to these structures, it is possible to effectively prevent vibrations from being transmitted between the housing 6 and the spring 8.

  Next, the structure of the air compressor which is 2nd Embodiment is demonstrated using FIG. The air compressor according to the second embodiment is mainly generated by an electric motor (not shown) that is a power unit, a compressed air generation unit 23 that is driven by the power unit to generate compressed air, and the compressed air generation unit 23. A tank unit 24 for storing compressed air and a compressed air extraction unit for extracting compressed air from the tank unit 24 are provided. The compressed air generation unit 23 includes a cylinder, a piston that reciprocates inside the cylinder, and a crank mechanism that drives the piston. As the electric motor (not shown) rotates, the piston reciprocates via the crank mechanism, and generates compressed air. The compressed air is accumulated in the tank unit 24 through a communication pipe (not shown).

  A compressed air take-out part is provided on the tank part 24. The compressed air take-out section has pressure reducing valves 22A and 22B. The primary pressure sides of the pressure reducing valves 22A and 22B are connected to the tank portion 24, and the secondary pressure sides of the pressure reducing valves 22A and 22B are connected to the compressed air outlets 25A, 25B, 25C and 25D.

  Similarly to the first embodiment, the pressure reducing valves 22A and 22B have a housing having an air passage communicating the primary pressure side and the secondary pressure side, a piston movably provided inside the housing, and a spring for pressing the piston. A seat packing, which is a valve body that moves with the piston as the piston moves to open and close the air passage, is provided. The pressure reducing valves 22A and 22B are provided with adjusting knobs 22C and 22D, respectively, and the operator can adjust the pressure on the secondary pressure side by operating the adjusting knobs 22C and 22D. Also in this embodiment, the noise generated from the spring can be suppressed by using the pressure reducing valve of the present invention.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, the second modified example and the third modified example may be combined, and an elastic body may be provided at both ends of the spring. In the present embodiment, the pressure reducing valve capable of adjusting the spring pressure of the spring has been described. Needless to say, the present invention can be applied to a pressure reducing valve with the pressure fixed.

Partial sectional view of the pneumatic tool of the first embodiment of the present invention Sectional view of the pressure reducing valve of the present invention Sectional drawing of the 1st modification of the pressure-reduction valve of this invention Sectional drawing of the 2nd modification of the pressure reducing valve of this invention Sectional drawing of the 3rd modification of the pressure reducing valve of this invention Overall view of the air compressor of the second embodiment of the present invention Cross-sectional view of a conventional pressure reducing valve

DESCRIPTION OF SYMBOLS 1 Nailing machine (pneumatic tool) main body 2 Pressure reducing valve 6 Housing 6A Main housing 6B Adapter part 6C Plug part 7 Piston 7A Seat packing (valve body)
8 Spring 10, 11, 12, 13 Elastic body 14 Primary pressure chamber 15 Secondary pressure chamber 16 Separator 17 Air passage

Claims (11)

A housing having an air passage communicating the primary pressure side and the secondary pressure side;
A piston movably provided inside the housing;
A spring that presses the piston;
A valve body that moves together with the piston as the piston moves to open and close the air passage;
In the pressure reducing valve that automatically opens and closes the air passage according to the pressure on the primary pressure side and the secondary pressure side,
A pressure reducing valve, wherein an elastic body is disposed between the spring and the housing or between the spring and the piston. The pressure reducing valve according to claim 1, wherein the pressure on the secondary pressure side can be adjusted by adjusting the spring pressure of the spring.   The pressure reducing valve according to claim 1 or 2, wherein the spring and the elastic body are arranged on a secondary pressure side.   The pressure reducing valve according to any one of claims 1 to 3, wherein the elastic body is disposed at a central portion in the axial direction of the spring.   The pressure reducing valve according to claim 4, wherein the elastic body has an axial length corresponding to at least two turns of the spring.   The pressure reducing valve according to claim 4 or 5, wherein the elastic body is bonded to the spring.   The said piston penetrates the inside of the said spring, The said elastic body is arrange | positioned between the said piston and the said spring, Comprising: The radial inside of the said spring is characterized by the above-mentioned. 5. The pressure reducing valve according to 5.   The pressure reducing valve according to any one of claims 4 to 7, wherein a dimension of the elastic body in a radial direction of the elastic body is larger than a gap between the spring and the housing.   The pressure reducing valve according to any one of claims 1 to 3, wherein the elastic body is disposed at an axial end portion of the spring. A pneumatic tool having a main body, a pressure accumulating chamber provided in the main body, and a pressure reducing valve provided between the pressure accumulating chamber and the outside of the main body,
The pressure reducing valve includes a housing having an air passage communicating the primary side and the secondary pressure side;
A piston movably provided inside the housing;
A spring that presses the piston;
A valve body that moves together with the piston as the piston moves to open and close the air passage;
In the pressure reducing valve that automatically opens and closes the flow path between the primary pressure side and the secondary pressure side according to the pressure difference,
An air tool, wherein an elastic body is disposed between the spring and the housing or between the spring and the piston. A power unit, a compressed air generating unit that is driven by the power unit to generate compressed air, a tank unit that accumulates compressed air generated by the compressed air generating unit, and a unit for taking out compressed air from the tank unit An air compressor having a compressed air outlet,
The compressed air outlet has a pressure reducing valve;
The pressure reducing valve includes a housing having an air passage communicating the primary pressure side and the secondary pressure side;
A piston movably provided inside the housing;
A spring that presses the piston;
A valve body that moves together with the piston as the piston moves to open and close the air passage;
In the pressure reducing valve that automatically opens and closes the flow path between the primary pressure side and the secondary pressure side according to the pressure difference,
An air compressor, wherein an elastic body is disposed between the spring and the housing or between the spring and the piston.