JP3234547U - Torque measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque measuring device having a simple structure capable of accurately measuring even a small tightening torque.
SOLUTION: An air cylinder 5 fixed to a base 2 and a swing arm having one end connected to a piston rod 4 of the air cylinder and the other end swingably supported about a rotation axis with respect to the base. The rotating shaft has a head that can be engaged with a screw tightening tool, and the rotating shaft and the swing arm are fixed so as to rotate integrally with the air cylinder. The torque measuring device 1 is provided with a compressed air supply pipeline, a detecting means for detecting a change in the internal pressure of an air cylinder, and a pressure reducing valve 7 for adjusting the internal pressure.
[Selection diagram] Fig. 1

Description

The present invention relates to a torque measuring device for measuring the tightening torque of a screw by a tool such as a torque wrench.

When assembling parts of machine tools and machine products, it is often required to fasten the screws with the specified tightening torque. For example, when a tip, which is a replacement cutting edge, is attached to a cutting tool used for turning, if the tip is tightened with a torque stronger than the specified value, the tip may be slightly distorted and the accuracy of turning may be reduced. be. On the contrary, if the tightening torque is smaller than the specified value, the tip may be loosely mounted. In such a case, a torque measuring device may be used to determine whether the tightening torque of the tool is within the specified range.

Conventionally, a torque measuring device using a hydraulic pressure is known. Patent Document 1 describes a torque verification device that measures the output torque of a torque wrench by measuring the internal pressure applied to the oil sealed in the pressure receiving device when the measuring bolt is tightened with a torque wrench. ing.

Jikkenhei 02-128933

However, in the torque verification device described in Patent Document 1, if the tightening torque value is too low with respect to the internal pressure of the pressure receiving device, the pressure receiving device may not be sufficiently pressed, and it may be difficult to measure a small torque value. Further, since the pressure receiving device is an enclosed type, it is necessary to replace the pressure receiving device in order to change the measurement range.

The problem to be solved by the present invention is to solve the above-mentioned conventional problems, to provide a torque measuring device having a simple structure that can measure accurately even with a small tightening torque and can easily change the measuring range. To provide.

In order to solve the above problems, an air cylinder fixed to a base and one end connected to the piston rod of the air cylinder, and the other end swinging so as to be swingable around a rotation axis with respect to the base. An arm is provided, the rotating shaft has a head that can be engaged with a screw tightening tool, and the rotating shaft and the swing arm are fixed so as to rotate integrally with the air cylinder. Is a torque measuring device provided with a compressed air supply pipeline, a detecting means for detecting a change in the internal pressure of an air cylinder, and a pressure reducing valve for adjusting the internal pressure.

Further, it is preferable that the supply pipeline is provided with a check valve.

Further, it is preferable that the swing arm and the piston rod are connected in a substantially L-shape in a plan view.

With the configuration according to claim 1 of the present invention, it is possible to accurately measure even a small tightening torque, and it is possible to provide a torque measuring device having a simple structure in which the measurement range can be easily changed. ..

According to the second aspect of the present invention, the torque measuring device can be moved to the place of use and used by closing the check valve.

According to the third aspect of the present invention, the length of the swing arm and the piston rod can be shortened to reduce the size of the torque measuring device.

It is a top view of the torque measuring apparatus of an embodiment. It is the AA end view of FIG. 1 which shows the attachment structure of the swing arm and the rod connecting member of an embodiment. It is a partial cross-sectional view which shows the positional relationship of the air cylinder, the piston rod and the swing arm of embodiment. It is a pneumatic circuit diagram of the torque measuring device of an embodiment.

The mode for carrying out the device is shown below. As shown in FIG. 1, the torque measuring device 1 of the present embodiment includes a base 2 and a swing arm 3 swingably supported by the base 2. The shaft that supports the swing arm 3 with respect to the base 2 is a rotating shaft having a head that can be engaged with a screw tightening tool. The rotating shaft of the present embodiment is a perforated bolt 31 in which a hexagonal hole is formed in the head portion and a screw is formed in the shaft portion, but other shapes may be used. As shown in FIG. 2, the perforated bolt 31 is inserted into a hole formed on the base end side of the swing arm 3, and the pipe nut 32 is screwed into the shaft portion protruding below the swing arm 3. ing. As a result, the swing arm 3 is sandwiched between the head of the hole bolt 31 and the pipe nut 32, and the swing arm 3 and the hole bolt 31 are fixed to each other so as not to rotate. Further, the pipe nut 32 is rotatably supported by the bearing hole 21 formed in the base 2, so that the swing arm 3 can swing around the axis of the hole bolt 31 with respect to the base 2. ..

A piston rod 4 of an air cylinder 5 is connected to the tip end side of the swing arm 3 via a link. In the present embodiment, as shown in FIGS. 1 to 3, a rod connecting member 41 capable of sandwiching the swing arm 3 is provided at the end of the piston rod 4, and the rod connecting member 41 and the swing arm 3 are provided. Are slidably connected by pins 42. The swing arm 3 and the piston rod 4 of the embodiment are connected in a substantially L-shape in a plan view.

As shown in FIG. 1, the air cylinder 5 of the embodiment includes a compressed air supply line that can be connected to the compressed air source 81. The air pressure of the compressed air discharged from the compressed air source 81 is adjusted by the regulator 82, and the compressed air is provided with a check valve 83, a pressure reducing valve 7, and a pressure gauge 6 and passes through a supply line connected by a flexible hose 84 to the air cylinder 5. Supplied. As shown in FIGS. 1 and 4, in the supply line of the present embodiment, the pressure gauge 6 is a detection means for detecting a change in the internal pressure of the air cylinder 5 between the check valve 83 and the air cylinder 5. And a pressure reducing valve 7 provided with a pressure adjusting screw 71 and capable of adjusting the internal pressure. After the compressed air is supplied to the air cylinder 5, the torque measuring device 1 can be moved to the place of use by closing the check valve 83 provided on the flexible hose 84.

Next, the operation of the torque measuring device 1 when measuring the tightening torque of the screw tightening tool will be described. When the air cylinder 5 is filled with compressed air and the screw tightening tool is engaged with the holed bolt 31 to perform the tightening operation, the tip of the swing arm 3 becomes the air cylinder 5 as the holed bolt 31 rotates. A force acts that moves in the approaching direction and tries to push the piston rod 4 into the air cylinder 5. When the tightening torque exceeds the force with which the air pressure of the air cylinder 5 pushes the piston, the piston rod 4 is pushed into the air cylinder 5.

When the piston rod 4 is pushed into the air cylinder 5, the piston moves in a direction of narrowing the air chamber of the air cylinder 5, and the internal pressure of the air cylinder 5 rises. The internal pressure of the air cylinder 5 at this time is measured by the pressure gauge 6, and the load applied by the screw tightening tool is calculated by multiplying the measured pressure value by the pressure receiving area of the air cylinder 5. The tightening torque can be calculated from the calculated load value and the length of the arm of the tightening tool.

When measuring a small torque, if the internal pressure of the air cylinder 5 is higher than the tightening torque, the piston rod 4 may not be pushed into the air cylinder 5. In such a case, a small torque can be calculated by operating the pressure adjusting screw 71 of the pressure reducing valve 7 to reduce the internal pressure of the air cylinder 5. Since the air cylinder 5 presses the piston rod 4 by air pressure instead of hydraulic pressure, it is possible to easily reduce the pressure by discharging air to the outside. This makes it possible to provide a torque measuring device having a simple structure capable of accurately measuring even a small tightening torque.

Although the present invention has been described above by taking an embodiment as an example, the present invention is not limited to the above embodiment and can be in various modes. For example, in the present embodiment, the internal pressure of the air cylinder 5 is measured by the pressure gauge 6, but it is also possible to calculate the tightening torque by measuring the force applied to the air chamber of the air cylinder 5 using the load gauge. be. Further, by using the torque measuring device 1 of the present invention, it is possible to check whether the changed set torque value is within the standard range with a torque wrench whose set torque value can be changed, or to manually tighten the set torque value. You can practice tightening work while checking the correspondence between the force and the actual tightening torque.

1 Torque measuring device 2 Base 21 Bearing hole 3 Swing arm 31 Hole bolt 32 Pipe nut 4 Piston rod 41 Rod connecting member 42 Pin 5 Air cylinder 6 Pressure gauge 7 Pressure reducing valve 71 Pressure regulating screw 81 Compressed air source 82 Regulator 83 Reverse Stop valve

Claims (3)

An air cylinder fixed to the base and
One end is connected to the piston rod of the air cylinder, and the other end is provided with a swing arm that is swingably supported around a rotation shaft with respect to the base.
The rotating shaft has a head that can be engaged with a screw tightening tool, and the rotating shaft and the swing arm are fixed so as to rotate integrally.
A torque measuring device provided with a compressed air supply pipe, a detecting means for detecting a change in the internal pressure of the air cylinder, and a pressure reducing valve for adjusting the internal pressure. The torque measuring device according to claim 1, wherein the supply pipeline is provided with a check valve. The torque measuring device according to claim 1 or 2, wherein the swing arm and the piston rod are connected in a substantially L-shape in a plan view.

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