JPS63256375A - Revolution controller utilizing fluid pressure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotation control device that uses fluid pressure, and more specifically, for example, when tightening bolts/nuts using an impact wrench. By introducing exhaust pressure during driving, the compressed air for driving the wrench is smoothly switched from low pressure to high pressure, thereby making it possible to perform bolt/nut tightening work more efficiently and without strain. This invention relates to a rotation/rotation control device using fluid pressure.

[Background of the Invention] Traditionally, automobile production factories have used many bolts and nuts that require high tightening torque when assembling various parts, and pneumatically driven impact wrenches have often been used for this purpose. . It has been pointed out that the following problems actually exist when tightening bolts/nuts using this impact wrench. That is, when the operator presses the operating lever during a tightening operation, the wrench body rotates at a high output. As a result, the bolts/nuts are tightened with high torque. In this case, if the bolt/nut has thread grooves with a relatively short pitch, the bolt may be inserted into the nut without the thread grooves and the thread threads interlocking with each other, and as a result, the thread threads may This often causes the so-called gajiri to collapse. Depending on this problem, you will have to use new bolts/nuts again.

Therefore, conventionally, in order to prevent the occurrence of such gnashing, bolts/nuts are tightened by skillfully adjusting the operating lever of an impact wrench.

That is, in the case of a one-motion type impact wrench, in the first stage of bolt/nut tightening, the operating lever is lightly pressed to limit the flow rate of compressed air to some extent and weaken the tightening force of the impact wrench. After several bolts/nuts have been successfully screwed together in this way, carefully press the operating lever until the specified tightening torque is reached.
This will tighten the nut.

In addition, with a 2-motion type impact wrench that can switch between low-torque tightening and high-torque tightening functions, the bolt/nut has a low torque until several threads are screwed together. Perform torque tightening, then switch the lever and tighten the bolt/nut with high torque.

Since such conventional methods require a high level of skill from the operator, it is practically difficult for unskilled workers to tighten bolts/nuts. However, as a result of the bolt/nut tightening work being highly dependent on the skill of the individual, the drawback is that the efficiency of the work process cannot be improved.

[Object of the Invention] The present invention has been made in order to overcome the above-mentioned disadvantages, and is intended to change the supply fluid pressure, which is the driving force of the rotating mechanism, from low pressure to high pressure in a device that uses fluid pressure, such as an impact wrench. Automatically switching from low torque rotation to high torque rotation by setting a time lag between the two and controlling the switching, for example, avoids the occurrence of thread fraying when tightening bolts/nuts, and reduces the rotational force during tightening work. It is an object of the present invention to provide a rotation control device using fluid pressure, which makes it possible to further improve the production efficiency of the working process used.

[Means for achieving the object] In order to achieve the above object, the present invention provides a first directional control valve equipped with a timer that operates when exhaust pressure is introduced;
and a second directional switching valve operated in response to pressure from the first directional switching valve, and after a time set in the timer has elapsed, the second directional switching valve switches from low pressure fluid to high pressure fluid. The valve is characterized in that the valve is configured to rotate under switching control with a time difference.

[Embodiment] Next, an impact wrench will be cited as a preferred embodiment of the rotation control device using fluid pressure according to the present invention, and will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, compressed air is supplied to the impact wrench 10 as a driving fluid. The rotation control device according to the present invention includes a control valve 12 and a switching valve 14 for switching the flow rate and flow path of this compressed air. This fluid supply system will be explained. First, a pipe line 18 is connected to a pipe 16 extending from a pressure i air supply source (not shown), and this pipe line 18 branches in the middle, and one branch line adjusts the opening of a variable throttle. It is connected to the inlet port E of the switching valve 14, which will be described later, through a regulator 20 that can set the air flow rate to a predetermined value, and the other branch path is directly connected to the other inlet port P of the switching valve 14. be done. Although switching control valves having various structures can be used as the switching valve 14, in the present invention, for example, a spool type pneumatic pilot switching valve is employed. As can be easily understood from the figure, this switching valve 1
4 has three ports: inlet boat E, inlet boat P and outlet port A. As shown in FIG. 2, the inlet boat E and the outlet boat A are in communication in the initial state, and when air pressure is introduced into the pilot boat 22, the communication state between the inlet port E and the outlet port A is changed. When released, the entrance boat P is configured to communicate with the exit boat.

The outlet port A is connected to an inlet port 26 of the impact wrench 10 via a conduit 24. This entrance boat 26
The impact wrench IO is driven by compressed air being introduced from the holder.

Therefore, this impact wrench IO has a control lever 28.
is provided, and by pressing this operating lever 28, compressed air is introduced into an air motor (not shown) housed inside the main body of the impact wrench 10 to drive it. In this case, the present invention does not require a two-motion type impact wrench that can be switched between low-torque tightening and high-torque tightening operations. In other words, a 1-motion type impact wrench is sufficient.

A socket 32 is engaged with a rotating shaft 30 extending from an air motor (not shown) of the impact wrench 10.

An exhaust port 34 is provided adjacent to the inlet port 26, and the introduced compressed air is led out from the exhaust port 34 through a conduit 36.

There, the conduit 36 is connected to the control valve 12 and also to the muffler 40 via the variable throttle 38 . Therefore, the exhaust gas led out from the impact wrench 10 is reduced to a predetermined pressure by the variable throttle and flows into the control valve 12. As shown in FIG. 2, the control valve 12 includes a timer 42 and a solenoid valve 44.
A pilot pipe line 46 branches off from the pipe line 36 and is connected to a timer 42, while this pipe line 36 is also connected to an inlet boat 48 of a solenoid valve 44. In this case, the timer 42 is activated when a predetermined air pressure is applied from the pilot line 46, and after the set time has elapsed, the solenoid of the electromagnetic valve 44 is energized and the electromagnetic valve 44 is opened. The solenoid is deenergized when the air pressure ceases to act, and as a result, the electromagnetic valve 44 is closed. A pilot line 50 extends from the outlet port 49 of the electromagnetic valve 44, and this pilot line 50 connects to the pilot boat 22 provided in the aforementioned switching valve 14.
connected to.

The rotation control device using fluid pressure according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, the regulator 20 is adjusted to throttle the air flow downstream of the regulator 20 and set to a predetermined air pressure.

Next, the timer 42 constituting the control pulp 12 is set to a time such that the solenoid valve 44 switches after a predetermined period of time has elapsed. These can be arbitrarily selected depending on the size of the bolt/nut to be tightened and the pitch or shape of the threaded groove. In the case of this embodiment, the set time of the timer 42 is set to about 0.5 seconds, for example.

After performing the preparation work in this way, the bolt tightening work is started. Therefore, a bolt head or nut (not shown) is fitted into the socket 32 of the impact wrench IO. Next, when the operating lever 28 is pressed, compressed air is introduced into an air motor (not shown) in the impact wrench IO, the impact wrench IO is activated, and the rotation of the air motor is transmitted to the socket 32 via the rotating shaft 30. This causes the bolt or nut to rotate. In this case, compressed air whose flow rate has been previously throttled by the regulator 20 and reduced to a predetermined pressure is introduced into the impact wrench 10, so the bolt or nut rotates at low speed and low torque. Note that the compressed air that rotates the air motor is led out from the exhaust port 34 and passed through the pipe line 36.
, is exhausted to the outside from the muffler 40 via the variable throttle 38, and is introduced into the timer 42 via the pilot pipe 46. Therefore, the timer 42 is activated by the introduced compressed air, and after a predetermined set time (about 0.5 seconds in this case) has elapsed, the timer 42 energizes the solenoid of the electromagnetic valve 44 to activate the solenoid. Switch valve 44.

That is, the inlet port 48 and the outlet port 49 communicate with each other,
The air exhausted from the impact wrench IO is passed through the pilot pipe 50 to the pilot boat 2 of the switching valve 14.
2, and the switching valve 14 is switched by the air pressure. As a result, the inlet port E and the outlet boat A communicate with each other, and compressed air from the pipe 16, which is set at the pressure necessary to tighten the bolt/nut to a predetermined specified torque, is introduced into the impact wrench 10. reach.

Therefore, as the bolt or nut rotates at a high speed and approaches the seating state on the tightening member, its torque gradually increases, and finally it is tightened under the specified torque and the tightening process is completed. I will do it.

The relationship between the time during this period and the bolt/nut tightening torque is shown in FIG.

In this way, the thread grooves and threads of the bolt/nut screw together, and in the early stages of tightening, the bolt/nut is driven by low-pressure compressed air and is tightened at a low speed, making it possible to prevent gagging. In addition, the low pressure drive time can be selected as appropriate depending on the size of the bolt/nut, the pitch and shape of the thread groove, and after the time has elapsed, the pressure fluid is switched to perform high torque tightening. Bolt/nut tightening work can be performed extremely efficiently.

Next, when the impact wrench 10 stops pressing the operating lever 28, the bolt/nut tightening work is completed. Upon completion of the work, exhaust air no longer flows through the control pulp 12, the timer 42 is reset to its initial state, and the solenoid of the electromagnetic valve 44 is also deenergized. Therefore, the solenoid valve 44 is closed and returns to its original position. As a result, pilot air pressure does not act on the switching valve 14, so that the switching valve 14 is also switched to its original state.

With the above, everything returns to its initial state and is ready for the next bolt/nut tightening operation. In this way, since the process of switching from low torque to high torque is all performed automatically, there is no need for a particularly skilled person to tighten bolts/nuts, etc.

[Effects of the Invention] As described above, according to the present invention, the valve mechanism equipped with a timer is actuated by the exhaust air pressure when driving the impact wrench, and the compressed air supplied to the impact wrench is changed from low pressure air to high pressure air. automatically switched to. Therefore, it is possible to completely avoid screw grooves and screw threads from becoming loose or damaged when tightening bolts/nuts, and as a result, it is possible to significantly improve tightening work efficiency in line production processes such as factories. Effects can be obtained.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
It is possible to use other tightening mechanisms and tap mechanisms in place of the impact wrench, and the pressure fluid is not limited to air pressure. Various improvements and designs can be made without departing from the gist of the present invention. Of course, it is possible to change.

[Brief explanation of drawings]

Fig. 1 is a schematic front view of a rotation control device using fluid pressure according to the present invention, Fig. 2 is a circuit diagram of a rotation control device using fluid pressure according to the present invention, and Fig. 3 is a bolt/nut tightening It is a graph showing the relationship between time and tightening torque. 10...Impact wrench 12...Control valve 14...Switching valve 20...Regulator 22...Pilot boat 26...Inlet boat 34...Exhaust boat 36...Pipe line 38...・Variable aperture 42...Timer 44・
... Solenoid valve 46 ... Pilot pipe line 48
...Entrance boat 49...Exit boat 50.
・Pilot conduit

Claims (3)

[Claims] (1) A first directional control valve equipped with a timer that is activated when discharge pressure is introduced, and a second directional control valve that is activated by receiving pilot pressure from the first directional control valve; A rotation control device using fluid pressure, characterized in that the second directional switching valve is controlled to rotate from low pressure fluid to high pressure fluid with a time difference after a time set by a timer has elapsed. (2) In the device according to claim 1, the first
The directional switching valve consists of a solenoid valve, and when a timer set time elapses, the solenoid of the first directional switching valve is energized, and the solenoid of the second directional switching valve is energized.
A rotation control device that uses fluid pressure by switching a directional control valve. (3) In the device according to claim 1 or 2, the device is a rotation control device that uses fluid pressure and includes an impact wrench.