Change-over switch capable of automatically controlling gas interval pressure

Abstract

The change-over switch capable of automatically controlling the gas interval pressure comprises a shell (1), a switch plate spring (2), a switch contact (3), a switch pressing column (4), a rotating pressing rod (5), an over-travel spring (6), a pressure spring (7), a piston rod (8), a sealing ring (9) and a piston cylinder (10) with a screw, the rotating pressing rod (5) pushes the switch plate spring (2) through the switch pressing column (4), the over-travel spring (6) is arranged between the rotating pressing rod (5) and the piston rod (8), and the pressure spring (7) is arranged in the shell (1). A pressure spring (7) is arranged between the piston rod (8) and the shell (1), and a sealing ring (9) is arranged between the piston rod (8) and the piston cylinder (10) with the screw, so that up-down piston motion can be formed under the pushing of air pressure, after the switch pressing column (4) presses the switch plate spring (2) to pass through the highest point, the switch pressing column (4) continuously moves for a certain distance in an over-travel mode under the action of the over-travel spring (6), the air pressure is slowly reduced, and the piston rod (8) moves downwards under the action of the pressure spring (7). And when the switch plate spring (2) returns, the normally closed point is switched on.

Description

Technical Field

[0001] The invention discloses a conversion switch for automatically controlling gas interval pressure, which is composed of a shell, a switch plate spring, a switch contact, a switch pressure column, a transfer pressure rod, an overtravel spring, a pressure spring, a piston rod, a sealing ring and a piston cylinder with a screw. The conversion switch is used for automatic control of air pumps and the like which require interval pressure, and belongs to the field of mechanical control switch component products. Background Art

[0002] The existing air compressor pressure control switch can control the motor to shut down when the pressure reaches the rated value, and automatically start the motor when the pressure is lower than the set value. It is large in size, complex in structure, high in cost, and has a limited control pressure range. For example, the pressure difference of the conventional air compressor switch is only 3 kg per square centimeter. The pressure relief valve installed on the existing vehicle-mounted air pump only starts to relieve pressure after the air pressure reaches the rated value, and cannot automatically start or shut down the air pump motor within a certain pressure range, and cannot be used with an air blow gun.

[0003] There are also electronic range pressure control switches on the market, which also have many components, complex structures and high costs, require separate power supply, and have restrictions on where they can be used.

[0004] Generally, when a machine is working, it is not desired that the switch oscillate at the critical point. Compared with electronic switches, it is easier to achieve interval action by setting the capacitor charge and discharge path or adding a locking loop resistor to the voltage comparator. However, for mechanical switches, the external force is greater than the critical point force, the switch action function is converted, the external force is slightly lower than the critical point force, the switch returns to its original position, and oscillation is formed. If mechanical interval control is to be formed, two critical points need to be set for the mechanical switch and they need to be interlocked. The structure is complex, the size is large, and the cost is high, such as the current air compressor switch. Summary of the invention

[0005] In order to solve the problem of automatic conversion control of the above-mentioned gas interval pressure, reduce the size of the switch and reduce the cost, the present invention provides a conversion switch for automatically controlling the gas interval pressure, which realizes automatic control of the gas interval pressure by applying the existing standard travel switch, overtravel spring and pressure spring, and is equipped with a piston moving under pressure.

[0006] The technical solution adopted by the conversion switch for automatically controlling the gas interval pressure of the present invention to solve its technical problems is: it includes a shell, a switch plate spring, a switch contact, a switch pressure column, a rotating pressure rod, an overtravel spring, a pressure spring, a piston rod, a sealing ring and a piston cylinder with a screw. After being applied to a vehicle-mounted air pump, the air pump can be expanded to use functions such as an air blow gun. The rotating pressure rod pushes the switch plate spring through the switch pressure column, an overtravel spring is provided between the rotating pressure rod and the piston rod, a pressure spring is provided between the piston rod and the shell, and a sealing ring is provided between the piston rod and the piston cylinder with a screw, so that an up and down piston movement can be formed under the push of air pressure. The switch plate spring with the switch contact can realize the normally closed and normally open conversion of the switch. When the air pressure increases and reaches the rated value after the air pump is powered on, The piston rod moves upward, pushing the pressure spring and the overtravel spring upward, thereby pushing the rotating pressure rod and the switch pressure column to press the switch plate spring past the highest point, and the switch is normally closed and disconnected. At this time, the air pump is powered off, and the switch plate spring continues to move to the left, the rebound force becomes smaller, and the switch pressure column continues to overtravel for a distance under the action of the overtravel spring. Because the air pump is powered off, the air pressure slowly decreases, and the piston rod moves downward under the action of the pressure spring. When the air pressure value decreases to a certain value and the downward displacement of the piston rod is greater than the continued overtravel distance of the overtravel spring, the switch plate spring returns to its position, the normally closed point is connected, and the air pump is automatically powered on to work, instead of repeatedly switching on and off with instantaneous changes in pressure. By adjusting the stiffness of the overtravel spring, automatic control of air pressure in a certain range can be achieved.

[0007] The beneficial effects of the product of the present invention are: discovering and applying the characteristic that the rebound force of the switch pressure column of the existing standard travel switch becomes smaller after passing the highest action point, and utilizing the combined effect of the overtravel spring, the pressure spring and the piston to achieve a small size, a simple structure, good standardization, novelty, low cost, and expansion of the use of vehicle-mounted air pumps with good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Attached pictures Figure 1 】 is an assembly drawing of the present invention; the markings in the figure are: 1. housing; 2. switch plate spring; 3. switch contact; 4. switch pressure column; 5. rotating pressure rod; 6. overtravel spring; 7. pressure spring; 8. piston rod; 9. sealing ring; 10. piston cylinder with screw. DETAILED DESCRIPTION

[0009] A switching switch for automatically controlling gas interval pressure of the present invention, as shown in the accompanying drawings, comprises: a housing (1), a switch plate spring (2), a switch contact (3), a switch pressure column (4), a pressure rod (5), an overtravel spring (6), a pressure spring (7), a piston rod (8), a sealing ring (9) and a piston cylinder with a screw (10). After being applied to a vehicle-mounted air pump, the air pump can be expanded to use a blow gun and other functions. The pressure rod (5) pushes the switch plate spring (2) through the switch pressure column (4). An overtravel spring (6) is provided between the pressure rod (5) and the piston rod (8). A pressure spring (7) is provided between the piston rod (8) and the housing (1). A sealing ring (9) is provided between the piston rod (8) and the piston cylinder with a screw (10), so that an upward and downward piston movement can be formed under the push of air pressure. The switch plate spring (2) with the switch contact (3) can realize the normally closed and normally open conversion of the switch. When the air pressure increases and reaches the rated value after the air pump is powered on, the piston rod (8) moves upward, pushing the pressure The spring (7) and the overtravel spring (6) move upward, thereby pushing the transfer rod (5) and the switch pressure column (4) to press the switch plate spring (2) past the highest point, and the switch is normally closed and disconnected. At this time, the air pump is powered off, and the switch plate spring (2) continues to move to the left, the rebound force becomes smaller, and the switch pressure column (4) continues to overtravel for a distance under the action of the overtravel spring (6). Because the air pump is powered off, the air pressure slowly decreases, and the piston rod (8) moves downward under the action of the pressure spring (7). When the air pressure value decreases to a certain value, the downward movement displacement of the piston rod (8) is greater than the continued overtravel movement distance of the overtravel spring (6), the switch plate spring (2) returns to its position, the normally closed point is connected, and the air pump is automatically powered on to work, instead of the air pressure changing with the pressure at the critical point and the switch repeatedly acting. By adjusting the stiffness of the overtravel spring (6), the automatic connection or disconnection of the conversion switch within a certain air pressure range can be achieved.

[0010] The product of the present invention is applied to a standard travel switch. The operating force of the switch pressure column (4) thereof becomes unstable and smaller after exceeding the maximum rebound force due to the switch plate spring (2) structure of the internal structure. After a large number of measurements, it is generally found that the maximum value is 2.2N and then becomes smaller to 1.5N. The switch pressure column (4) can continue to move about 2mm. This provides a possibility for realizing a conversion switch for automatically controlling the gas interval pressure of the present invention, and realizes automatic control of different gas pressure interval values ​​through different force arm lengths of the pressure rod (5). After detailed calculation of the diameters of each spring and piston, the above performance requirements can be met. The product is applied to the cylinder sleeve valve plate frame integrated with the telescopic foot and the air pump with a one-way air cooling circuit from the motor side developed by the company, ensuring that the air pump can be used in conjunction with an air gun, achieving a small size, a simple structure, convenient vehicle mounting, and expanded uses. The product is creative and has reliable performance after prototype trial production and trial operation.

Claims

1. A switch for automatically controlling the pressure of a gas interval, comprising: a housing (1), a switch plate spring (2), a switch contact (3), a switch pressure column (4), a pressure rod (5), an overtravel spring (6), a pressure spring (7), a piston rod (8), a sealing ring (9) and a piston cylinder with a screw (10), wherein: After being applied to a vehicle-mounted air pump, the air pump can be expanded to have a function of using an air blow gun. The pressure rod (5) pushes the switch plate spring (2) through the switch pressure column (4). An overtravel spring (6) is provided between the pressure rod (5) and the piston rod (8). A pressure spring (7) is provided between the piston rod (8) and the housing (1). A sealing ring (9) is provided between the piston rod (8) and the screwed piston cylinder (10). The switch plate spring (2) carries the switch contact (3) to realize the normally closed and normally open switch conversion. When the air pressure increases and reaches the rated value after the air pump is powered on, the piston rod (8) moves upward, pushing the pressure spring ( The piston rod (8) moves downward under the action of the pressure spring (7). When the pressure value decreases to a certain value and the displacement of the piston rod (8) is greater than the distance of the overtravel spring (6), the switch plate spring (2) returns to its original position and the normally closed point is connected.

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