JPS5852537A - Torque sensor - Google Patents

Abstract

PURPOSE:To make a titled sensor thin, and also to raise its sensitivity, by providing a connecting means for connecting an input shaft and an output shaft, etc., through said input shaft and output shaft which have been placed so that the axial cores coincide with each other, and a spring member placed so as to extend in the diameter direction. CONSTITUTION:A gear 5 of a torque sensor is formed on the outside circumference of a connecting part 10 having a large diameter, which has been coupled with an output shaft 3, and between the connecting part 10 and an input shaft 2, a plate spring 8 which extends in the diameter direction and connects them is provided. Also, the plate spring 8 is constituted of several pieces. According to such a constitution, as for a torque sensor by this invention, size in the axial direction substantially becomes on the whole thickness of only the connecting part by the spring member, and accordingly, it can be manufactured very thinly. Also, when the number of pieces of the plate spring, width, thickness, etc. are changed, a measuring range of torque can be selected freely, and the sensitivity can be elavated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a sensor for detecting torque.

As shown in Fig. 1, this type of conventional sensor has a thin round bar called a torsion bar l placed between an input shaft 2 and an output shaft 3, and the torsion bar 1 is prevented from twisting due to the torque applied to the shaft. is being detected.

As a method of detecting torsion of the torsion bar 1, the gear number 5 for position detection and the
were installed, and the rotational direction twist of the input shaft and output shaft was detected by the difference in output position (1) between the electromagnetic pickups 6 and 7, respectively.

In the conventional sensor using a torsion bar, the phase angle is proportional to the torsion bar's N in addition to the torque, and is inversely proportional to the fourth power of the radius. Therefore, if the radius is made smaller, the sensitivity becomes higher, but the strength becomes weaker, so there is a limit to how far K can be made thinner, and the length of the torsion bar 1 needs to be increased.

Therefore, there was a drawback that the sensor became large.

An object of the present invention is to provide a thin and highly sensitive torque sensor.

An embodiment of the torque sensor according to the present invention shown in FIG. 2 and FIG. 4 will be described.

That is, in each figure, the gear 5 is formed on the outer periphery of a large diameter connecting portion 10 connected to the output shaft 3, and the gear 5 is formed on the outer periphery of a large diameter connecting portion 10 connected to the output shaft 3
A leaf spring 8 is provided between the input shaft 2 and the input shaft 2 and extends in the radial direction to connect them, and the leaf spring 8 is composed of several sheets as shown in FIG.

The operation of the torque sensor according to the present invention will be illustrated below.
When torque is applied between the output shaft 8 and the output shaft 8, a force that bends the leaf spring 8 acts. The leaf spring 8 is displaced so that the torque due to the deflection force of the leaf spring and the torque between the input shaft 2 and the output shaft 8 are balanced. This displacement must be within the elastic limit of the leaf spring 8, but the longer the length of the leaf spring 8, the larger it becomes, and the thinner the leaf spring 8 is, the smaller the width, the larger it becomes. Therefore, the magnitude of the torque to be detected [therefore,
The thickness, width, length, number, etc. of the leaf spring 8 may be determined. The displacement thus generated corresponds to the torque acting on each shaft 2, 8, and the gear 4 rotates with the rotation of each shaft.
Detection can be made in the same manner as in the prior art based on the phase difference between the outputs of the tortoise magnetic pickup 6.7 that occurs in response to an angle of 5°.

In addition to electromagnetic pickups, it is also possible to use an optical pickup to detect the position of the teeth and detect a phase difference.

Here, for example, if the number of teeth 4.5 is equal to m, the rotation angle of the shaft in one cycle of the output pulse is 2π4 radians, and the phase difference of the output pulse is ψ with respect to the output pulse l゛cycle ÷ If so, the displacement is approximately ψR/ff, where R is the radius to the end of the fifth spring connected to the output shaft side.
l and is proportional to the phase difference ψ. Torque can be determined from this displacement.

As described above, the torque sensor according to the present invention has the feature that the axial dimension is substantially equal to the thickness of only the connection portion formed by the spring member, and that an emergency VC#<< is possible. Furthermore, by changing the number, width, thickness, etc. of leaf springs, the torque measurement range can be freely selected, resulting in good productivity.

Note that the shape of the leaf spring, such as its thickness and width, does not have to be uniform throughout, and may be partially thickened or changed in one corner; It may also be from.

[Brief explanation of drawings]

FIG. 1 is a front view of a conventional torque sensor, FIG. 2 is a front view showing an embodiment of the torque sensor according to the present invention, FIG. 8 is a sectional view of the sensor shown in FIG. Figure IV-IV
FIG. In the figure, 2 is an input shaft, 8 output shafts, 4.5 are gears, 6.7 is a pickup, and 8 is a leaf spring. The same symbols in the figures indicate the same or equivalent parts. Agent Shin Kuzuno - 12 Figure 2

Claims (1)

[Claims] The input shaft and output shaft are arranged so that their axes coincide with each other,
The input and output shafts are connected through one or more spring members arranged in a radial direction, and rotational direction displacement is applied between them in response to the torque between the input and output shafts. A torque sensor comprising a coupling means and a detection means for detecting a phase difference between rotational pulses corresponding to the rotations of the input and output shafts.