JPH0318641Y2 - - Google Patents

Description

[Detailed Description of the Invention] 3-1 Field of Industrial Application The present invention relates to an improvement of a rotary vane type air motor that is widely used in rotary air machines such as impact wrenches.

3-2 Conventional technology As a means of obtaining different outputs for left and right rotation with a conventional rotary vane type air motor, there are two methods: (i) shifting the position of the intermediate exhaust from the center in the cylinder to effectively utilize the angle in one direction; (ii) A method of changing the output by restricting the left and right air flow path and final exhaust using a reverse valve. (iii) A method of installing a regulator in the circuit. A method of reducing the output on one side by manual switching is known.

3-3 Problems that the invention attempts to solve In the conventional method (i), the left and right output ratio is at most 1:
The maximum value is about 1.5, and it is difficult to obtain a larger change. In addition, method (ii) cannot be said to be effective in terms of air utilization efficiency, and there is a problem that starting problems are likely to occur especially when low output is required.Furthermore, method (iii)
This method was complicated and required manual operation each time. The present invention aims to provide a rotary vane type air motor that solves this problem with a simple configuration.

3-4 Means for solving the problem The configuration of the present invention that solves the problem is a rotary vane type that can obtain rotation in the left and right directions by converting the air flow path in the left and right directions using a reverse valve. In an air motor, the air flow path in the direction of rotation in which a small output is to be obtained by reducing the output of either the left or right side is connected to a large flow path with a relatively large cross section immediately before opening into the power generating cylinder. , a small flow path with a minute cross section is branched into two flow paths that communicate with the cylinder, and a check valve is installed on the large flow path side.
The structure is such that the flow direction from the reverse valve to the cylinder is stopped and, conversely, communication from the cylinder to the reverse valve is opened. On the other hand, the branched small channel with a minute cross section is guided to a plate forming the side wall of the cylinder, and opens into the cylinder through a kidney hole bored in the plate.

3-5 Effect In the present invention, the cylinder intermediate exhaust is located at the center of the cylinder, and the structure in relation to the output relationship with the rotor vane is such that it generates both right and left rotation output. Only the air flow path in the direction of rotation where the output is to be reduced to obtain a small output is branched into two just before the cylinder as described above, and during intake, the large cross-section flow path is closed by a check valve, and the small cross-section flow path is closed by a check valve. Only the channel is opened to the kidney hole. The pressurized air sent to this flow path passes through the micro cross-sectional flow path and blows out from the kidney hole into the cylinder. This kidney hole is located at the bottom of the vane storage groove bored in the rotor, and the air ejected from this kidney hole pushes the vane in the groove toward the inner surface of the cylinder to form a pressure-receiving blade that generates rotational force. It serves as the driving force for rotational torque as power generation air. The check valve installed just before the cylinder means that the flow path up to this position has a volume cross section that is sufficiently balanced to the motor capacity, so there is no problem with air circulation, and when air is supplied, there is sufficient air supply up to this position. is carried out, and phenomena such as pressure drop cannot occur. That is, the air ejected from the kidney hole has sufficient pressure and the vane extrusion energy is sufficiently secured, so that the vane extrusion is reliably performed. After pushing out the vane, the air expands rapidly within the cylinder, reducing the pressure exerting pressure on the vane and creating torque. The volume cross section of the small cross section path is determined by selecting a volume commensurate with the required generated torque. According to the above structure, even when a small amount of air is supplied, the motor has good startability and can be operated normally with an output torque of less than half, or in some cases less than 1/4, of the normal torque that the motor should generate. If this motor rotates in the opposite direction to the rotation direction in which the minute torque is generated,
Both of the aforementioned two branched flow channels, that is, the large capacity flow channel with a relatively large cross section and a check valve, and the micro flow channel that opens into the kidney hole, form a flow channel that is sufficient as an exhaust route. It is possible to generate an output commensurate with the motor capacity.

3-6 Example This example is an example of use in an impact wrench. In the figure, 1 is a reverse valve, 2 is a rotor, 3 is a vane, 4 is a vane storage groove, 5, 5', 5'' are air flow paths, 6 is a branch flow path branched from the air flow path,
7, 7' are kidney holes opening into the vane storage groove 4 of the branch flow path, 8 is an intermediate exhaust port, 9 is a cylinder, 10, 10' is a main flow path in the same cylinder,
11 is a check valve hole that serves as a check valve; 12
13 is the reverse valve bush, 13 is the air inlet, 14 is the trigger, 15 is the rear end plate, 16 is the air flow path 5', 5'' and the main flow path 10, 1.
0' are communication holes drilled in the rear end plate 15, and A to Z indicate air passage points.
In this embodiment, the pressurized air is supplied to the air inlet 13.
The air is introduced into the reverse valve 1 via the throttle valve and the air flow path 5, and is sent to one of the left and right air flow paths by the reverse valve. When the pressurized air is sent to the air flow path 5'', it is not throttled and flows directly to the main flow path 10'.
The air flows into the cylinder 11 through the air, rotates the rotor 2 with high output, flows out into the main flow path 10 on the opposite side, pushes the chuck valve ball 11, flows into the air flow path 5', and passes through the reverse valve 1. It is emitted into the atmosphere. The flow of air in this direction of rotation is shown in FIGS. 11-15. Air passes through points A→B→C→D→Y→R→Q→P→O in the diagram.
[Partial Q→V→W→O]→N→M→L→Z→G→
F → E → S → U (partially O → N' → T → U) → Atmospheric flow.Next, when the reverse valve 1 is switched and the pressurized air is sent toward the air flow path 5', the air Check valve ball 1 that serves as a check valve in the flow path
1 to close the flow path to the main flow path 10. On the other hand, the blocked pressurized air flows into the branch passage 6 having a small flow area and is blown out from the kidney hole 7 to the Hehn storage groove 4. The blown out slightly pressurized air reliably causes the vane 3 to pop out and flows into the rotor chamber of the cylinder, thereby rotating the rotor 2 with a small output. This counter-rotating air flow is shown in Figures 6-10. Air passes through point A
→B→C→D→X→E→F→G→H→J→K→
J'→H'→Z→L→M→N→O→P→Q→R→S→
U [Partly N-N'→T→U]→Flows with the atmosphere.

3-7 Effects of the invention According to the invention, by adding a simple configuration of a communication path to the vane chamber and a check valve, a large output difference of more than twice the rotational speed and rotational force between the left and right sides can be achieved. Not only can this be achieved, but there is also the effect that it is easy to obtain a minute output without starting problems at low output rotations, and the purpose can be achieved at low cost.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional side view of the embodiment, Fig. 2 is a partially cutaway rear view of the same, Fig. 3 is a sectional view along the line - Fig. 2, and Fig. 4 is a view taken from the - arrow direction in Fig. 3. Figure 5 is an enlarged front view showing the rear end plate; Figures 6 to 10 show the air flow in Figures 1 to 5 in the case of reverse rotation; Figure 6 is the same as Figure 1. Figure 7 is the same as Figure 8 in Figure 2.
The figure is an explanatory diagram showing the air flow of FIG. 3, FIG. 9 of FIG. 5, and FIG. 10 of FIG. 4. 11th~
Figure 15 shows the air flow in Figures 1 to 5 in the case of forward rotation. 14
The figure is an explanatory diagram showing the air flow of FIG. 5, and FIG. 15 is an explanatory diagram showing the air flow of FIG. 4. 1... Reverse valve, 2... Rotor, 3...
Vane, 4... Vane storage groove, 5, 5', 5''...
Air flow path, 6... branch flow path, 7, 7'... kidney hole, 8... intermediate exhaust port, 9... cylinder, 10, 10'... main flow path, 11... chuck valve ball, 12 ... Reverse valve bush, 13 ... Air inlet, 14 ... Trigger, 15 ... Rear end plate, 16 ... Communication hole, A to B ... Air passage point.

Claims (1)

[Scope of utility model registration request] In a rotary vane type air motor, the rotation direction can be changed by switching the air passage using a pair of rotors and cylinders.
A branch passage for minute flow is provided just before one of the air passages opens into the cylinder of the power generation chamber, and a check valve is provided in the main passage to restrict the flow only in that direction, and to restrict the flow in the opposite direction. A rotary vane type air motor that is characterized by producing an output difference of more than twice in each rotational output without any restrictions.