JPH04122467U - Tightening torque control mechanism of general-purpose impact wrench - Google Patents

Abstract

(57) [Summary] [Purpose] To control the tightening torque of a general-purpose impact wrench.
This is done by detecting that the pressure of exhaust air has risen to a predetermined value. [Structure] A normally open solenoid valve 4 is provided in the middle of the compressed air supply line 2. A pressure switch 5 is attached to the exhaust line 3 to detect when the pressure of exhaust air has risen to a predetermined value. Upon receiving the detection signal from the pressure switch 5, the sequencer 6 closes the solenoid valve 4, stops the supply of compressed air, and ends the work of the general-purpose impact wrench.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a general-purpose impact wrench used on engine assembly lines. It relates to a torque control mechanism.

0002

[Conventional technology]

Assembly lines for industrial products such as automobile engines and automatic transmissions The tightening work of bolts and nuts is indispensable in many applications. ・There are many nuts whose tightening torque is strictly controlled. like this For work, use a general-purpose impact wrench (air tool), QL type torque wrench, and a bending wrench. A plate torque wrench etc. is used. In addition, we also have tightening torque control machines. There are air tools with built-in functions, and the method for controlling the tightening torque is as follows: How to electrically detect the amount of distortion in the main shaft of an air tool, installing an oil chamber inside the air tool Methods such as stopping the spindle rotation using hydraulic pressure, and air motor methods are used. It is used.

0003

[Problem that the idea aims to solve]

However, the conventional general-purpose impact wrench mentioned above generally has a tightening torque of There is a large variation on the high torque side with respect to the set value, and the operation is based on the operator's experience. The disadvantage was that it was dependent on one's ability. In addition, the tightening torque using a QL wrench set and proof that the work has been completed (e.g. black magic check). There was also the inconvenience that these required many man-hours. Furthermore, tightening Air tools with built-in torque control functions are themselves expensive. Also, when setting high torque, the reaction force of tightening must be held by the operator's hand. Therefore, there were limitations in terms of safety.

0004

[Means to solve the problem]

This invention solves the above-mentioned problems and is a general-purpose device that operates by receiving a supply of compressed air. Automatically operates when the impact wrench tightens to the specified tightening torque. In the tightening torque control mechanism of a general-purpose impact wrench that controls the stop, Pressure detection means for detecting the pressure of exhaust air discharged from a general-purpose impact wrench; , an on-off valve disposed in the middle of the compressed air supply line and the pressure detection means detect a predetermined pressure. A control hand that receives a signal that detects the force and closes the on-off valve to stop the supply of compressed air. Tightening torque control for a general-purpose impact wrench characterized by having a stepped structure. It is a control mechanism.

[0005]

[Effect]

According to the above-mentioned method, the exhaust pressure increases in the tightening area of the general-purpose impact wrench. By focusing on this and adding pressure detection means, on-off valves, and control means, we have developed a An impact wrench can be provided with a tightening torque control function. sand In other words, the pressure detection means can detect when the exhaust gas of a general-purpose impact wrench has risen to a predetermined value. When detected, the control means that receives this signal outputs a signal to close the on-off valve. The valve closes and stops supplying compressed air to the general-purpose impact wrench, so it is suitable for general-purpose impact wrenches. The impact wrench stops operating and the tightening torque is controlled to the specified value. .

[0006]

【Example】

An example of the tightening torque control mechanism of the general-purpose impact wrench according to the present invention is shown in Figure 1. I will explain based on this. The general-purpose impact wrench 1 supplies compressed air through the compressed air supply line 2. After receiving and tightening bolts and nuts, exhaust air is released from exhaust line 3. Discharge. In this invention, an electromagnetic valve is installed at a suitable location in the compressed air supply line 2 as an on-off valve. A valve 4 is provided, and a pressure sensor for detecting the pressure of exhaust air discharged from the exhaust line 3 is provided. A pressure switch 5 is provided as force detection means. These solenoid valves 4 and pressure switches The switch 5 is connected to a sequencer 6 provided as a control means, and the sequencer 6 When the pressure switch 5 receives a signal indicating that a predetermined exhaust air pressure has been detected, an electromagnetic switch that is normally open Close valve 4 to stop supplying compressed air. In addition, 7 is a solenoid valve 4 and a pressure switch. 5 and the power supply for the sequencer 6, 8a and 8b are pressure gauges, and 9 is a display lamp. ing.

[0007] Hereinafter, the operation of the present invention described above will be explained. General-purpose impact wrench 1 includes Compressed air regulated to a constant pressure is supplied by an omitted regulator. supplied The pressure of the compressed air can be confirmed using the pressure gauge 8a. When starting work, solenoid valve 4 is It is open and compressed air is supplied to the general purpose impact wrench to do the job. and As the tightening of bolts and nuts approaches completion, the exhaust air pressure increases and reaches the specified level. The pressure switch 5 is activated when the pressure rises to that level. Operation of this pressure switch 5 Upon receiving the signal, the sequencer 6 closes the solenoid valve 4, stops the supply of compressed air, and The indicator lamp 9 is turned on to notify the operator. In other words, the tightening torque is at the specified value. This is detected from the rise in exhaust air pressure, and the compressed air supply is automatically stopped. It indicates that the work is completed. In addition, the tightening torque control mechanism of the general-purpose impact wrench of this invention is currently being installed on the assembly line. When in use, the loading and unloading of workpieces can be detected with a limit switch (not shown). This can be linked to the work completion signal in such a way that the This allows the bolt/nut This prevents forgetting to tighten the bolts. Note that the operating pressure of the pressure switch 5 is determined by the pressure gauge 8b. You can check and adjust accordingly. In addition, the solenoid valve 4 and pressure switch 5 and general-purpose The length and diameter of the hose between it and the impact wrench 1 should be determined to ensure the accuracy of the tightening torque. This is an important element and must be selected appropriately taking into consideration the various conditions at the site.

[0008]

[Effect of the idea]

According to the present invention described above, it is possible to easily control the tightening torque of a general-purpose impact wrench. It is effective in reducing work man-hours and improving product reliability and quality.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 General-purpose impact wrench 2 Compressed air supply line 3 Exhaust airline 4 Solenoid valve (on/off valve) 5 Pressure switch (pressure detection means) 6 Sequencer (control means)

Claims (1)

[Scope of utility model registration request] Claim 1: In a tightening torque control mechanism for a general-purpose impact wrench, which controls the general-purpose impact wrench to automatically stop operating when the general-purpose impact wrench operates by receiving a supply of compressed air and tightens to a predetermined tightening torque. , a pressure detection means for detecting the pressure of exhaust air discharged from a general-purpose impact wrench, an on-off valve disposed in the middle of the compressed air supply line, and a signal indicating that the pressure detection means detects a predetermined pressure; A tightening torque control mechanism for a general-purpose impact wrench, comprising a control means for closing an on-off valve and stopping the supply of compressed air.