torque screwdriver

Abstract

The present invention provides a torque screwdriver capable of adjusting a torque gradient formed by a spring constant of a coil spring. The torque screwdriver of the present invention includes: a main shaft to which a bit can be attached at the front end; a cylindrical portion holding the main shaft in a rotatable manner; a coil spring biasing the main shaft toward the base end of the cylindrical portion; and a base end side of the main shaft formed integrally with the main shaft. A holding member that rotates and holds the base end of the coil spring and has a holding hole that opens toward the base end side; an extension member that is equipped with the holding hole; a base end member that is provided at the base end of the cylindrical portion, wherein a torque gradient adjustment mechanism is provided , the torque gradient adjustment mechanism includes: a torque gradient adjustment hole, which is opened in a position opposite to the rotational movement path of the extension member in the inner surface of the base end member, and can allow a part of the extension member to enter; the torque gradient adjustment member , which fits with the torque gradient adjustment hole to adjust the depth of the protruding member entering the torque gradient adjustment hole.

Description

technical field [0001] The present invention relates to a torque screwdriver capable of tightening with a desired tightening torque, and more specifically, to a torque screwdriver capable of adjusting the torque gradient of a coil spring biasing a spindle. Background technique [0002] There is known a coil spring type torque screwdriver capable of fastening a fastening member such as a screw with a desired set torque. In such a torque screwdriver, the main shaft is biased against the grip part by the coil spring, and the main shaft is equipped with a ball that fits into a recess provided in the grip part. Moreover, when the fastening member is fastened, if a tightening torque greater than a set tightening torque acts between the main shaft and the grip, the balls will overcome the elastic force of the coil spring and come out of the recess, and the main shaft will be opposite to the grip. Idling on the handle. Thereby, an appropriate fastening torque of the fastening memb...

AI Technical Summary

Problems solved by technology

[0007] However, there is a deviation in the spring constant of the helical spring

Therefore there is the following problem: Even if it is a torque screwdriver of the same specification, if for example Figure 7 If the gradient (referred to as "torque gradient") is different as shown in the line B, the same tightening torque cannot be set even if the slider is moved uniformly.

Images