JPS6010874B2 - Tightening angle control device for impact tightening tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vertical mounting angle control device for an impact tightening tool.

Conventionally, when a bolt or the like is fastened using an impact tightening tool, the torque of the main shaft is used to check the attachment condition.

However, this method of checking the attachment using torque control does not necessarily ensure accurate tightening. For example, if the tap is not fully set or there is dirt attached to the threaded part, the main shaft torque of the tightening tool may reach the set torque and stop even if the tightening is not completed completely. Or give a sign indicating completion of tightening. In the present invention, when carrying out such rare fitting work of bolts, etc., instead of controlling the torque of the main shaft, the angle of the attachment is controlled to ensure complete vertical attachment.

The present invention will be explained below based on illustrated embodiments. Although the illustrated embodiment is a pneumatic type, an electric type is also applicable, and the impact wrench will be described below. In the figure, 1 is the main body of the impact wrench, 2 is a motor installed in this main body, which rotates the main valve V by supplying high-pressure air into the motor chamber by operating the operating lever L. The rotation is transmitted to the striking part 3, where the required striking force is generated to cause the main shaft 4 to rotate by striking, and a switching valve 5 is provided on the way where the air passing through the main valve V is supplied to the air motor part. The air motor 2 is selectively rotated forward or reverse by switching the valve.

Further, a main body joint 7 and a main body lid 8 are successively superimposed on the outer side of the main body 1 to be integrated, and the angle control device of the present invention is provided inside the main body joint and the main body lid.

This angle control device is fixed to a part of the main shaft 4, and the rotation of the main shaft is transmitted through a transmission shaft 6 which passes through the air motor section, preferably through the motor shaft and projects into the main body joint. ing. The main shaft gear 12, which is rotatably supported by the main body diamond 8, and the rear end of the transmission shaft 6 are connected via a pin P, and the main shaft gear 12 and the transmission shaft are connected to a bearing B,
At the same time, a shaft 1 is attached to the main body lid 8.
4, and a spur gear 15 supported through a bearing B2 is engaged with the intermediate gear 13, thereby transmitting the rotational driving force of the main shaft gear to the spur gear. . Further, a valve receiver 9 is inserted into the outer periphery of the rear end of the transmission shaft as shown in FIG. The rectangular projection 9a is fitted to the rear end of the motor shaft so as to rotate together with the motor shaft, and the inside thereof is hollow, and the tip surface thereof has a notch 9b.
The outer periphery of the cylindrical valve receiver 9 is supported by a valve bush 0' which is supported by iron in the main body joint 7, and the valve 11 is inserted into the valve receiver by iron.

As shown in detail in FIG. 4, this valve 11 has a cylindrical shape with a protrusion 11a having a width smaller than the width of the notch 9b of the valve holder on the outside of one end, and a notch 11b on the circumferential surface of the valve holder. A bracken is formed in the valve receiver so that the valve 11 fits inside the notch of the valve receiver, and the valve 11 rotates only the width difference or gap between the notch 9b and the protrusion 11a to open and close the air hole 9d. will be combined. At this time, a kick spring S is interposed between the valve and the valve receiver to restore the valve 11 to its original state. Further, an adjustment dial 17 is provided on the spur gear 15 to face the stop lever shaft 16 which is rotatably supported by the plunger 9.
The tip of this stop lever shaft has a conical protrusion 16.
When the plunger 9 is pushed out by the action of air pressure, the conical protrusion 16a is pressed against the conical concave surface 15a of the spur gear, and rotational force is transmitted from the spur gear, so that they rotate together. The stop sign lever 18 is a ring-shaped stop sign lever 18 that has a partial protrusion that adjusts how many times the main shaft rotates to tighten bolts, etc. after the seat surface contacts the fastened object. is fixed on the stop lever shaft.

A kick spring S is interposed between the stop sign lever 18 and the adjustment dial 17, and by this spring, when the adjustment dial is rotated, the stop sign lever is moved along its protrusion 1.
The position of 8a is rotated and returned to its original position. Further, a stop valve 21 is provided facing the adjustment dial 17, and a stop lever 22 is swingably provided between both 17 and 21, and is automatically restored to its original state by a kick spring S.
The tip of the stop lever 21 is locked to the stop valve 21, and when the stop lever shaft welding machine is pressed by the spur gear and rotates together with the movement of the plunger, the ring-shaped stop sign lever 18 is rotated. The protrusion 18a kicks the end of the stop lever, thereby swinging the stop lever against the kick spring, releasing the engagement with the stop valve, closing the stop valve, and stopping the air motor. The sliding of the plunger 19 is performed by operating the pilot valve 20 in response to the opening/closing operation of the valve 11. Normally, the high pressure air supplied to the impact wrench is supplied to the main valve V and the switching valve as shown in FIG. 5 to a stop valve 21, and from this stop valve 21 it is supplied to the air motor. However, at the position where it exits this stop valve, a passage is branched and a part of the high pressure air is sent to the pilot valve 20. Supplied. The supply boat 20a from the switching valve of the pilot valve 20 is a ring-shaped boat 7a formed on the outer peripheral side of the valve bush 10 on the main body joint 7 from the boat 20b. When the impact wrench is rotating under no load, as shown in FIG.
However, the air hole 9d is closed by the valve 11. Therefore, when the main valve V is opened by operating the operating lever L, air is supplied to the air motor chamber and rotated to the outside of the air motor, but some of the branched air is blocked by the valve 11 via the pilot valve. When the air motor rotates the main shaft 4, the transmission shaft 6 attached to the main shaft also rotates. As a result, the intermediate gear 13 and the spur gear 15, which are sequentially meshed with the main shaft gear 12 which is engaged with the transmission shaft 6, are also rotated. At this time, since the plunger is not pushed out, the spur gear and the stop lever shaft 16 are separated and the shaft 16 is in a stopped state. In this state, when a bolt or the like is tightened and the seat surfaces come into contact and an impact force is generated on the impact wrench, due to the characteristics of this impact wrench, the air motor stops momentarily at the time of impact. The valve receiver 9 and the valve 11 were also rotating, but when the motor stops for a moment, the valve receivers also stop. At this time, the valve 11 held in the valve receiver still tries to rotate in the rotational direction even if the valve receiver 9 stops due to its inertia. As a result, as shown in FIG. 6D, the valve 11 rotates so that the protrusion 11a swings within the allowable range within the notch 9b of the valve receiver, and the air hole 9d by the valve 11 is moved from the closed state to the sixth position. When the exit is made as shown in Figure C, the air that has been stopped in the boat 7a flows in from the small hole 10a through the top pipes 9d and 11b, and the air supplied to the valve 11 flows into the space inside the main body lid and main body joint. It is discharged to the atmosphere from the exhaust port 8a through the flow path.This causes the pilot valve 20 to connect the boats 20a and 2.
When a pressure difference occurs between 0b and 0b and the pilot valve 20 slides to the left as shown in FIG. 6A, the air pressure that was being supplied to the boat 20a is conducted through the pilot valve. Plunger chamber 2
3. As a result, the plunger 19 slides to the right under pressure, and the conical protrusion at the tip of the stop lever shaft is brought into pressure contact with the conical concave surface of the spur gear, and the stop sign lever that is locked to the spur gear and the shaft. 18 and rotates as shown in FIG. 6B. The stop sign lever protrusion 18 is driven by a spur gear and rotates.
When the bar 22 contacts the end of the stop lever 22 and presses it, the bar 22 swings against the attached kick spring, and as a result, the tip of the stop lever 22 moves as shown in FIGS. 7B and E'. When the lock with the stop valve 21 is released, the stop valve 21 protrudes against the built-in spring pressure, blocks the passage between the switching valve and the air motor, stops the air supply, and stops the air motor. Stop.
When this air motor stops, the main shaft rotates by a predetermined angle after the bearing surface of the bolt, etc. contacts the surface of the object to be tightened according to the angle pre-adjusted with the adjustment dial, and this causes the tightening to proceed. This is something that must be done reliably and firmly. As shown in Figure 7, when the air motor stops when the shirt is off,
The spur gear, stop lever, etc. all stop, but the air pressure is applied to the plunger and stops, leaving the bar shaft in pressure contact with the spur gear.

However, when the stop valve 21 is closed, the air passage between the switching valve and the air motor chamber is blocked by the stop valve, and the air pressure no longer acts on the pilot valve, and the built-in spring pressure automatically restores the air passage. At the same time, air pressure ceases to act on the plunger chamber, and the spring S built into the stop lever shaft automatically returns the stop lever shaft to the spur gear, separating the stop lever shaft from the spur gear, which is the same state as during no-load rotation as shown in Figure 5. becomes. At the same time, the valve 11, which has rotated due to inertia, is returned by the built-in kick spring S to close the air hole 9d. The stop valve 21 and the stop lever 22 are also automatically returned to their original positions by attached or built-in springs, thus waiting for the next operation. The power is taken out through the transmission shaft, and the valve provided on the outer periphery of the transmission shaft is opened and closed by using the inertia generated when the main shaft is temporarily stopped when a blow occurs.

Since the stop valve is opened and closed and part of the air pressure applied to the impact wrench is used to rotate the angle control device and close the stop valve, the main shaft is controlled in angle rather than by torque regulation, so that it can be adjusted in advance after contact with the seat surface. It has the advantage that tightening can be performed reliably by rotating only a predetermined angle.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view, Fig. 2 is a sectional view taken along the X-X line in the previous figure, Fig. 3 is a sectional view taken along the Y-Y line in the same figure, Fig. 4 is a perspective view of the valve and valve receiver, and Fig. 5 The figures are explanatory diagrams of the state during no-load rotation, FIG. 6 during impact, and FIG. 7 when the shirt is off.
C is a cross-sectional view showing the relationship between the valve, the valve bush, and the valve receiver, D is a perspective view thereof, and E is a cross-sectional view of the switching valve portion. 4...Main shaft, 6...Transmission shaft, 9...
... Valve receiver, 10 ... Valve bush, 11 ... Valve, 12 ... Main shaft gear, 13 ... Intermediate gear, 15 ... Spur gear, 16 ... Stop lever shaft, 17... Adjustment dial, 18... Stop sign lever, 19... Plunger, 20...
・...stop valve, 22...stop valve. lever. Figure 1 Figure 2 Figure 3 Figure 4 - A violent battle

Claims (1)

[Claims] 1. A transmission shaft that extracts the rotation angle of the main shaft, a group of gears that rotate with the rotation of this transmission shaft, and a valve bush and valve that momentarily stop when the transmission shaft rotates or when an impact occurs, and open and close using inertia. A valve device consisting of a receiver and a valve fitted in sequence, a pilot valve that changes the flow of air so that it comes into contact with the gear when the valve device opens, and a rotation angle of the main shaft that can be adjusted in advance. A stop lever shaft equipped with an adjustment dial to be set and a stop sign lever; a stop lever that swings by rotating the stop sign lever through contact between the gear and the stop lever shaft;
A tightening angle control device for an impact tightening tool comprising a stop valve which is locked or released by the stop lever to cut off the supply of air to the air motor chamber.