KR100628823B1 - Low inertia type spin valve for controlling maximum rotational speed - Google Patents

Abstract

The present invention relates to a rotation speed control valve used in a rotating device of an air tool such as a pneumatic grinder or a pneumatic drill, so that the risk of damage due to centrifugal force increases when the rotation speed of the air tool exceeds a predetermined standard so that the control is performed at a predetermined speed or less. To this end, the wing of the airfoil type is provided in the head portion of the valve, it characterized in that the valve can be opened and closed by using a change in lift force according to the flow rate of the air.

Air Tool, Air Foil, Lift, Low Inertia, Wing

Description

Low inertia type spin valve for controlling maximum rotational speed}             

1 is a cross-sectional view of a conventional air tool

2 is a cutaway view taken along line A-A of FIG.

3 is a cross-sectional view showing an operating state of FIG.

4 is a cross-sectional view showing an operating state of the spin valve of the present invention.

Figure 5 is a cross-sectional view showing a state in which the spin valve of another embodiment of the present invention operating

Figure 6 is a cross-sectional view showing another embodiment of the present invention

7 is a conceptual diagram for adjusting the lift of the airfoil-type wing

※ Description of the main parts of the drawings

1. High pressure air inlet 2. Valve

3. Spring 4. Centrifuge

5. Cylinder 6. Rotor

7. Bevel Gear 8. Grinder

9. Vane 10. Casing

11.Air Hole 12.Air Outlet

13. Spring stopper 14. Pin

15. Wing 16. Spring Adjustment Bolt

17. Adjusting bolt

The present invention relates to a valve for adjusting the maximum rotational speed of the air tool, and more particularly, in the air tool such as a pneumatic grinder or a pneumatic drill that operates by using the air pressure, The present invention relates to a low inertia spin valve device for controlling the maximum rotational speed of an air tool that enables automatic control below a predetermined standard.

1 is a cross-sectional view of a conventional air tool, wherein the high pressure air introduced through the high pressure air inlet 1 pushes the vanes 9 through the air holes 11 in the cylinder 5 to rotate the rotor ( 6) Rotate

At this time, the rotational force is transmitted to the bevel gear (7) and the rotational force to work by rotating the grinder (8) assembled with the bevel gear (7) and the grinder (8) is replaced with various tools depending on the purpose of use can do.

In addition, when the maximum speed is reached, the centrifugal force 4 pushes the valve 2 by the centrifugal force to block the high pressure air, thereby controlling the rotation speed within a predetermined standard.

2 is a side cross-sectional view of the cylinder and the rotor section cut along the line AA of FIG. 1, and vanes 9 mounted on the circumference of the casing 10, the air hole 11, and the rotor 6. Is configured to come into contact with the cylinder wall by centrifugal force, and the air injected into the cylinder presses the vanes 9 so that the rotor 6 is rotated and the actuated air opens the air outlet 12 of the cylinder 5. It is configured to be discharged through, Figure 3 is an operating state diagram for blocking the flow of high-pressure air by the centrifugal weight (4) of FIG.

The grinder is a sintered powdery grinding material. When the centrifugal force is applied by high rotational speed, there is a risk of breakage, and the shearing force can be more easily broken when working at high speed. However, since the weight of the centrifugal weight 4 is considerably large, the conventional valve device has a high inertia regardless of the output even when operating at the maximum rotational speed, thereby reducing the output of the air tool. The rotational speed is adjusted so that the centrifugal force and the force of the spring 3 are balanced so that the manufacture of the spring requires strict quality control, precise assembly is required, and the number of parts used in the valve also increases.

The present invention was devised to solve the problem at all times, and the object of the present invention is to provide a configuration for controlling the maximum rotational speed of the air tool by using lift force generated in proportion to the rotational speed irrespective of the centrifugal force.

Still another object of the present invention is to reduce the weight and simplify the configuration for the speed control to increase the output efficiency and to facilitate the manufacture.

In order to achieve the above object, the present invention installs the airfoil wing in the circumferential direction at the tip of the valve 2 so that the lift force generated in the wing and the elasticity of the spring 3 are balanced according to the rotational force. When the maximum rotational speed is reached, the valve moves toward the high pressure air inlet due to lift force, which blocks the flow path of the high pressure air, and when the flow rate is blocked and the rotational speed decreases, the valve returns due to the spring elasticity due to the decrease of the lifting force. It is configured to automatically control the maximum rotation speed by the wing of the airfoil type to allow the high-pressure air flows.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Prior to the detailed description of the configuration of the present invention the same as the conventional configuration will use the same reference numerals.

4 is a cross-sectional view showing a state in which the spin valve of the present invention operates, the high-pressure air inlet 1 through which the high-pressure air is introduced, the spring 3 so as to be in balance with the lift force according to the rotational speed, and the valve ( The airfoil wing 15 of the head portion 2, the spring stopper 13, and the pin 14 of the spring stopper for fixing the spring are provided to lift the valve 2 by the lifting force. It shows the state of blocking the flow path and the flow of high pressure air is formed, the state in which the high pressure air is introduced, the speed difference between the pressure portion and the suction portion of the wing occurs when the rotation speed of the wing 15 of the airfoil type And the pressure is formed differently by the speed difference. Since the speed at the pressure part is low, a higher pressure is formed than the suction part, and the valve is pushed up to the high pressure air inlet part 1, and the lifting force and spring elasticity at this time are increased. Equilibrium If the rotation speed of the air tool is higher than the rotation speed set at the maximum speed, the lift force is proportional to the rotation speed, so the lift force surpasses the spring elasticity and the valve operates upwards, blocking the flow of high pressure air. Due to this, the rotation speed of the air tool is limited within the set range. When the flow path is blocked and the rotation speed decreases, the lift force decreases, and the spring elasticity surpasses the lift force to return the valve. Therefore, the high pressure air flow path opens again. The process of inflow is repeated.

FIG. 5 is a structural diagram of a maximum speed regulating valve, which is simpler than the case of FIG. 4 and reduces the number of parts. The spring stopper 13 and the pin 14 are removed and the valve is inserted into the shaft. The force of the has a shape that is simply assembled by the spring adjustment bolt 16, the flow of high pressure air is opened and closed in the same manner as the operating principle in Figure 4 and the valve blocks the flow of high pressure air according to the number of revolutions When lift is decreased, it shows the operating state that opens the flow path of high pressure air.

And, Figure 6 shows a state in which the operation when the flow path is formed vertically by using such a spin valve in the conventional centrifugal valve is used because the centrifugal weight of the base (a) -shaped centrifugal valve is used to limit the opening and closing distance of the valve It is difficult to apply to a variety of flow paths, but the spin-type valve has the advantage of having a high applicability without difficulty in blocking the flow path vertically because the opening and closing distance can be freely controlled by the lifting force.

And, in the case of Figure 7 shows the fixing device of the airfoil-type wing (15), as shown in the enlarged picture, the angle of the wing is simply adjustable by the adjustment bolt 17, so the adjustment of the maximum rotation speed is Adjusting the angle of attack of the wing adjusts the lift, so it is not a strict quality control of the spring (3), but simply to set the balance between the maximum number of revolutions and lift.

The embodiments described above are only intended to help the overall understanding of the present invention, and it is obvious to those skilled in the art that such specific matters may be changed or changed within the scope of the present invention. will be.

As described above, the present invention obtains an increase in power and an increase in torque under the same conditions due to the small inertia force of the wing in the spin type valve, thereby improving efficiency, and dramatically reducing the number of parts used in the valve. The increase in productivity and cost reduction were achieved, and the rotational speed was achieved by simply changing the lift angle by adjusting the angle of attack of the wing, thus avoiding the strict management of spring production, thereby improving productivity. Therefore, the opening and closing distance of the valve is freely set as a device having a high applicability is a very useful invention in the tool industry using a rotating device.

Claims (2)

In the device for automatically controlling the rotation speed of the rotating body for driving the air tool, An air foil-type wing 15 is provided in the circumferential direction at the tip of the valve 2 provided at the inlet of the air inlet 1 through which air is introduced, and the lift force generated by the wing 15 and the spring 3 are The elasticity is balanced, but when the maximum rotational speed is reached, the valve moves toward the air inlet by increasing the lift force, blocking the flow path of the high pressure air, and when the lift force is reduced, the valve returns and the high pressure air is introduced. Low inertia spin valve device for maximum rotational speed control. The wing of the airfoil type attached to the head portion of the valve is characterized in that the angle of attack according to the elasticity of the spring (3) by using the angle of attack angle adjustment bolt 17 of the wing. Low inertia spin valve device for maximum rotational speed control.

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