JP2006281365A - Variable throttle mechanism of pneumatic tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To finely control the output of an air motor or the like of a pneumatic tool. <P>SOLUTION: A variable throttle mechanism of the pneumatic tool is constructed by a cylindrical rotary throttle valve 32, the tip opening of which is inclined and a throttle valve holder part 34 fitted to the rotary throttle valve and provided with an air outlet formed in the peripheral surface. The throttle valve connected to a dial is rotated to steplessly vary the opening area of the air outlet of the throttle valve holder part, thereby finely controlling the output of the air motor or the like so that the convenience to use of the pneumatic tool can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable throttle mechanism for a pneumatic tool, and more particularly to a variable throttle mechanism for a pneumatic tool that enables fine adjustment of an air supply amount.

  For pneumatic tools that use an air motor such as an air impact wrench or air grinder, a variable throttle mechanism (regulator) is provided so that the air flow rate can be controlled and the rotation speed of the air motor adjusted by operating the variable throttle. Is known.

Normally, this type of pneumatic tool's variable throttle mechanism has a structure in which a rotary throttle valve in which a plurality of holes of different diameters are arranged in the circumferential direction is provided in the air pipe on the outer peripheral surface of the cylinder. By rotating a dial connected to the valve, the air passage sectional area of the pipe is changed to adjust the air flow rate (Patent Document 1).
JP-A-8-336762 (paragraph number 0002)

  A variable throttle mechanism of a conventional general pneumatic tool rotates a rotary valve in which a plurality of holes having different diameters are arranged in a circumferential direction on the outer peripheral surface of a cylinder to change the air passage cross-sectional area of the pipe in a stepwise manner. The structure is such that the rotational speed of an air motor or the like is adjusted stepwise, and there is a disadvantage that fine adjustment cannot be performed.

  Therefore, a technical problem to be solved in order to enable finer adjustment and improve the usability of the pneumatic tool arises, and the present invention aims to solve the above problem.

  The present invention is proposed to achieve the above object, and a throttle valve capable of changing the cross-sectional area of the passage is provided in the passage from the air inlet to the exhaust outlet of the pneumatic tool, and the throttle valve is used for an air motor or the like. In the variable throttle mechanism of the pneumatic tool that can adjust the air flow rate of the cylinder, the cylindrical rotary throttle valve with the tip opening that is the air inlet of the cylindrical portion is inclined, and the rotary throttle valve are fitted, The throttle valve holder portion is formed with an air outlet on the peripheral surface, and the opening area of the air outlet of the throttle valve holder portion is changed steplessly according to the rotation angle of the rotary throttle valve. A variable throttle mechanism for a pneumatic tool is provided.

  In addition, a variable throttle for the pneumatic tool is provided in the passage from the air inlet to the exhaust outlet of the pneumatic tool, and a throttle valve that can change the cross-sectional area of the passage is provided so that the air flow rate to the air motor can be adjusted by the throttle valve. In the mechanism, a plurality of variable throttle mechanisms are provided in the passage from the air inlet to the exhaust outlet of the pneumatic tool, and the air flow rate can be adjusted in multiple stages by combining the adjustment operation amounts of the plurality of variable throttle mechanisms. The variable throttle mechanism of the pneumatic tool characterized by the above is provided.

  Further, one of the plurality of variable throttle mechanisms is provided in a silencer attached to an exhaust port of the pneumatic tool, and provides a variable throttle mechanism for a pneumatic tool.

  In the present invention, a stepless variable variable throttle is used as a variable throttle mechanism of a pneumatic tool, or a plurality of step variable variable throttles are used, so that the rotational speed of an air motor or the like can be finely adjusted. Usability of the pressure tool is improved.

  The present invention, as a variable throttle mechanism of a pneumatic tool, is fitted with a cylindrical rotary throttle valve having an inclined tip opening that is an air inlet of a cylindrical portion, and the rotary throttle valve, and has an air outlet on a peripheral surface. The throttle valve holder part is formed, and the opening area of the air outlet of the throttle valve holder part is changed steplessly according to the rotation angle of the rotary throttle valve, so that an air motor or the like The object of enabling fine adjustment of the rotation speed of the motor is achieved.

  FIG. 1 shows an air impact driver 1 as an example of a pneumatic tool, and has a known configuration in which a built-in air motor 2 rotationally drives an anvil 4 via an impact mechanism 3. The inside of the grip part 5 is divided into an inlet side air chamber 6 on the rear side (right side in FIG. 1) and an outlet side air chamber 7 on the front side, and a hose connector 8 attached to the lower end of the inlet side air chamber 6. And an air compressor (not shown) tank connected with an air hose.

An open / close valve 21 for controlling the start and stop of the air motor 2 is arranged in the upper part of the inlet side air 6 chamber, and a variable throttle mechanism 31 is coaxially arranged in front of the open / close valve. When the trigger lever 9 arranged on the front side of the grip part 5 is pulled, the inlet side air chamber 6 and the air passage 10 on the air motor 2 side communicate with each other, the air motor 2 rotates, and the inflowed air passes through the air motor 2 and the grip part 5 The air enters the outlet side air chamber 7 on the front side, and is discharged to the atmosphere through the silencer 11 attached to the lower end of the outlet side air chamber 7.

  FIG. 2 shows parts of the on-off valve 21 and the variable throttle mechanism 31. The on-off valve 21 includes a valve casing 22, a ball 23 in the valve casing 22, and a direct acting rod type actuator 24. An air inlet 25 formed on the rear peripheral surface of the valve casing 22 Inside the inlet side air chamber 6, a ball 23 closes the air outlet 26 at the center of the front surface of the valve casing 22 by a spring.

  The actuator 24 is inserted into a guide hole of an actuator guide portion 27 that protrudes forward from the front center of the valve body portion 22a of the valve casing 22, and the actuator guide portion 27 is a cylindrical throttle valve 32 of the variable throttle mechanism 31. It has a coaxial arrangement structure that is inserted inside. A dial 33 is attached to the front end of the throttle valve 32, and the dial 33 can be turned to adjust the throttle valve 32 to an arbitrary rotation angle.

  When the trigger lever 9 is pulled, the actuator 24 of the on-off valve 21 is pushed back by the trigger lever 9, and the actuator 24 pushes the ball 23 to open the air outlet 26 of the valve casing 22, and the high-pressure air in the inlet-side air chamber 6 Begins to flow into the air passage 10 on the air motor 2 side. Further, when the trigger lever 9 is pulled, the flange portion of the actuator 24 comes into contact with the casing cap 60 on the front end surface of the valve casing 22 and pushes the entire valve casing 22 backward to open the valve body portion 22a. High-pressure air flows into the throttle valve 32 from the outer peripheral surface of the gas, and the high-pressure air is supplied to the air motor 2 through the opening 34a of the throttle valve holder 34 and the air passage 10, and the air motor 2 is started.

  FIG. 3 shows the throttle valve 32, and the tip portion 32a that is cylindrical and exposed to the pressure air passage has a diameter larger than the other portions in accordance with the internal shape of the throttle valve holder portion 34, and the tip portion 32a The end face of the slab is cut obliquely so that the cross-sectional area of the pressurized air passage can be adjusted steplessly according to the rotation angle.

  As shown in FIGS. 2 and 3 (b), the throttle valve 32 does not block the inlet of the air motor side air passage 10 on the upper surface side at the rotation angle with the inclined opening 32b facing upward, and the air motor side air passage 10 The opening rate of the throttle valve 32 is 100%, and as the throttle valve 32 is rotated from this state, the tip end portion 32a of the throttle valve 32 gradually closes the opening 34a of the throttle valve holder portion 34, and FIG. 2 and FIG. ), The opening 34a of the throttle valve holder 34 is shielded. Thus, the throttle valve 32 in the variable throttle mechanism 31 of the present invention can adjust the pressure air passage in a stepless manner from fully open to fully closed within a rotation range of 180 degrees.

  Next, an embodiment in which a plurality of variable throttle mechanisms are provided in the air passage from the air inlet to the outlet of the pneumatic tool will be described. The configuration of the air motor 2 and the impact mechanism 3 of the air impact driver 1 shown in FIG. 4 is the same as that of the air impact driver 1 of FIG. 1, but here, in addition to the variable throttle mechanism 41 arranged coaxially with the on-off valve 21 The silencer 51 at the lower end of the outlet side air chamber 7 of the grip part 5 is also equipped with an exhaust throttle valve 52, and two variable throttle mechanisms are provided. Multi-stage adjustment is possible by combining two variable throttle mechanisms.

  FIG. 5 shows the on-off valve 21 and the variable throttle mechanism 41. The on-off valve 21 has a structure that is opened by pushing the actuator 24, and is the same as that shown in FIG.

  FIG. 6 shows the throttle valve 42 of the variable throttle mechanism 41 surrounding the on-off valve 21, and the tip 42a that is cylindrical and exposed to the pressure air passage is more than the other parts according to the internal shape of the throttle valve holder 44. As shown in (a), (b), (c), and (d), four circular vent holes 43, 44, 45, and 46 are provided at intervals of 90 degrees on the peripheral surface of the tip portion 42a. Yes. The four vent holes 43, 44, 45, 46 have an opening area changed in four stages. As shown in FIG. 5, an arbitrary vent hole is overlapped with the opening 44a of the throttle valve holder portion 44 to form an air passage. The air entering from the opening at the tip of the throttle valve 42 is supplied to the air motor 2 through the vent hole of the throttle valve 42.

  FIG. 5 shows a state where the air passage is not throttled by aligning the largest vent hole 43 upward with the opening 44a of the throttle valve holder 44, and operating the dial 47 to rotate the throttle valve 42 by 90 degrees. Thus, the area of the air passage can be switched to four stages.

  FIG. 7 shows a silencer 51 in which an exhaust throttle valve 52 is accommodated in a cylindrical exhaust chamber 53. The exhaust throttle valve 52 is a cylindrical rotary valve similar to the throttle valve 42 of FIG. 6, and the upper end is closed as shown in FIGS. 7 and 8, and the upper and lower intermediate parts and the lower peripheral surface are respectively. Four circular vent holes 54 are arranged at intervals of 90 degrees, and four circular vent holes 55, 56, 57, and 58 having different cross-sectional areas are provided on the upper peripheral surface, as with the throttle valve 42 in FIG. Are arranged at intervals of degrees.

  As shown in FIG. 7, the upper part of the exhaust throttle valve 52 is fitted to the throttle valve holder part 53a on the upper part of the exhaust chamber 53, and a dial 59 is attached to the lower end, and the circumference of the throttle valve holder part 53a is Match any of the four circular vents 55, 56, 57, 58 to the air inlet 53b formed in the surface (the same round hole as the largest vent 55 of the exhaust throttle valve 52) By doing so, the cross-sectional area of the exhaust passage can be adjusted in four stages. Therefore, the combination of the four-stage variable throttle valve 42 and the four-stage variable throttle valve 52 of the silencer 51 arranged coaxially with the on-off valve 21 enables a total of 16 stages of air motor speed adjustment.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope of the present invention, and it is natural that the present invention extends to those modifications.

The side sectional view of an air impact driver which shows one embodiment of the present invention. FIG. 2 is a cross-sectional view of an on-off valve and a variable throttle mechanism portion in FIG. FIG. 2 shows the throttle valve in FIG. 1, (a) is a plan view, and (b) is a side view. Side surface sectional drawing of an air impact driver which shows other embodiment. FIG. 5 is a cross-sectional view of the on-off valve and variable throttle mechanism portion in FIG. FIG. 4 shows the throttle valve in FIG. 4, and (a), (b), (c), and (d) are front views rotated 90 degrees each. Sectional drawing of the silencer in FIG. FIG. 7 shows the throttle valve in FIG. 7, and (a), (b), (c), and (d) are front views rotated 90 degrees each.

Explanation of symbols

1 Air impact driver
2 Air motor
3 Impact mechanism
4 Anvil
5 Grip part
21 On-off valve
22 Valve casing
23 balls
24 Actuator
31 Variable aperture mechanism
32 Throttle valve
32b inclined opening
33 Dial
34 Throttle valve holder
41 Variable aperture mechanism
42 Throttle valve
43, 44, 45, 46 Vent
47 Dial
51 silencer
52 Exhaust throttle valve
54 Ventilation holes
55, 56, 57, 58 Vent
59 Dial
60 Casing cap

Claims (3)

In the variable throttle mechanism of a pneumatic tool, a throttle valve that can change the cross-sectional area of the passage is provided in the passage from the air inlet to the exhaust outlet of the pneumatic tool, and the flow rate of air to the air motor can be adjusted by the throttle valve. ,
A cylindrical rotary throttle valve having an inclined tip opening that is an air inlet of the cylindrical portion, and a throttle valve holder portion that is fitted with the rotary throttle valve and has an air outlet formed on a peripheral surface thereof. A variable throttling mechanism for a pneumatic tool, characterized in that the opening area of the air outlet of the throttling valve holder portion changes steplessly according to the rotation angle of the rotary throttling valve. In the variable throttle mechanism of a pneumatic tool, a throttle valve that can change the cross-sectional area of the passage is provided in the passage from the air inlet to the exhaust outlet of the pneumatic tool, and the flow rate of air to the air motor can be adjusted by the throttle valve. ,
A feature is that a plurality of variable throttle mechanisms are provided in the passage from the air inlet to the exhaust outlet of the pneumatic tool, and the air flow rate can be adjusted in multiple stages by a combination of adjustment operation amounts of the plurality of variable throttle mechanisms. Variable throttle mechanism for pneumatic tools. 3. The variable throttle mechanism for a pneumatic tool according to claim 2, wherein one of the plurality of variable throttle mechanisms is provided in a silencer attached to an exhaust port of the pneumatic tool.

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