JPH04369444A - Wiring processor for force detector - Google Patents

Abstract

PURPOSE:To simplify wiring task and reduce an apparatus size as regards a multi-axis force detector. CONSTITUTION:In a multi-axis force detector comprising a plurality of electrostrictive bodies 1, 3, 4 each having a strain gage connected in series, a thin wiring processing plate 2 is interposed between any two electrostrictive bodies. Then terminals 21, 22, 23, 24, 25, 26 to be connected to a lead 9 of a strain gage are placed on the thin wiring processing plate.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-axis force detector used in working robots and the like. For example, work robots used for automatic mounting of electronic parts or automatic assembly of mechanical parts are equipped with a function to detect contact force between parts. For example, in the process of fitting a part gripped by a robot hand into a predetermined hole, if the axial position of the part is slightly shifted, the positional shift can be detected by detecting the contact force applied to the part. I can do it.

0002

[Prior Art] The most common type of force detector that has been incorporated into such robots is one in which a strain gauge is attached to a strain body in the form of a thin, flexible leaf spring. . That is, a strain gauge incorporated as a resistor of a Wheatstone bridge circuit is attached to a strain body that detects strain in each direction of a three-dimensional plane in the x, y, and z directions as well as in the rotational torque direction, and the output voltage of this bridge circuit is Distortion in each direction is detected by dynamically amplifying and detecting a voltage proportional to the distortion.

In conventional force detection devices, bridge circuits are generally connected via lead wires. Therefore, great care must be taken in connection processing (wiring processing) of the lead wires to prevent short-circuiting or disconnection of the lead wires, or peeling of the strain gauge. The present invention is directed to such lead wire wiring processing technology.

0004

[Problem to be Solved by the Invention] However, in the past, for wiring processing, a terminal group was formed on each strain-generating body as a connection relay point for lead wires, so it was necessary to secure a space for arranging the terminal group. As a result, the area of the strain-generating body becomes large, which hinders miniaturization of the entire detector. Furthermore, the wiring process for connecting terminal groups using lead wires is troublesome, and simplification of the process has been desired.

[0005]

[Means for Solving the Problems] It is an object of the present invention to solve the problems of the prior art as described above, and to provide a wiring processing device that realizes miniaturization of a force detector and simplifies wiring processing. There is a particular thing. In order to achieve the above object, the wiring processing device according to the present invention provides a multi-axis force detector in which a plurality of strain bodies connected in series are laminated, each having a strain gauge. A thin plate for wiring processing is sandwiched between them, and a group of terminals to which lead wires of the strain gauge are to be connected are arranged on the thin plate for wiring processing.

[0006] Preferably, the wiring processing thin plate has terminal groups on both sides thereof, and these terminal groups are connected via lead wires to strain gauges of the strain-generating body located on each side. According to one embodiment, the thin plate for wiring processing has a thick portion in the outer peripheral portion located outside the terminal group, and the thick portion provides contact with the respective strain-generating bodies located on both sides of the thin plate for wiring processing. Fixed. Preferably, the terminal group connected to the strain gauge of the corresponding strain body via lead wires is covered with a fixing agent or a moisture proofing agent applied to the thin plate portion surrounded by the thick portion. A predetermined number of through holes are formed in the thin plate for wiring processing, and it is also possible to draw out the wiring group including the lead wires in a concentrated manner to one side of the thin plate for wiring processing through the through holes.

[0007]

[Operation] According to the present invention, since the terminal group to which the strain gauge lead wires are connected is provided on a single wiring processing thin plate, the strain-generating body is no longer large enough to allow for extra space for providing the terminal group. Therefore, the size of the strain-generating body and, by extension, the entire force detector can be reduced. Although the size in the thickness direction increases slightly by the thickness of the thin plate for wiring processing, this is almost negligible since it can be formed from an extremely thin plate.

[0008] The thick portion provided on the outer periphery of the thin plate for wiring processing prevents the terminal group provided on the thin plate portion, the lead wires connected thereto, or the solder patch from coming into contact with the adjacent strain-generating body. That is, the thick portion acts as a kind of spacer. Further, since this thick portion can be used to connect to an adjacent strain-generating body, the thick portion also functions as a reinforcing and fixing portion.

[0009] After connecting the lead wires to the terminal group, coating the connection portion with a fixing agent or a moisture-proofing agent prevents fatigue disconnection or contact short circuit due to swinging of the lead wires, or leakage due to moisture. Wiring including lead wires can be intensively drawn out to one side of the thin plate for wire processing through the through holes formed in the thin plate, thereby simplifying the wiring processing work.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. In the following embodiments, the target force detector has a structure in which a plurality of strain bodies in the form of flexible thin plate springs are arranged in a stacked manner and connected in series. In the illustrated embodiment, a strain body 3 for detecting force (strain) in the x and y directions; a strain body 1 for detecting torque in the a and b directions and force (strain) in the z direction; and a strain body 1 for detecting torque in the a and b directions and force (strain) in the c direction Although there are three strain-generating bodies 4 to be detected, the number of strain-generating bodies is not limited to this (FIG. 1).

Strain gauges (not shown) are attached to each of the strain bodies 1, 3, and 4, and these strain gauges are used as resistances in a Wheatstone bridge circuit to differentially amplify the bridge output voltage. By extracting the voltage as a voltage proportional to the strain, force and torque in each direction can be detected. Note that the detection method and principle itself are well known, and therefore, the explanation thereof will be omitted.

According to the present invention, the wiring processing thin plate 2 is sandwiched between any two strain-generating bodies, for example, strain-generating bodies 1 and 3. As shown in FIG. 2, for example, the thin plate for wiring processing has a disk shape with a diameter corresponding to the strain body, and thick portions 12 are formed on the outer periphery of the thin plate, for example, at two locations facing each other in the diametrical direction. Each thick wall portion 12 has an appropriate number of mounting screw holes 13, for example three.
is formed. Mounting screws 3 are inserted into these mounting screw holes 13.
0 (FIG. 1), it can be integrally connected to the strain-generating bodies 1 and 3 located on both sides of the wiring processing thin plate 2.

Thin wall portion 11 (thick wall portion 1) of thin plate 2 for wiring processing
2) has a group of terminals (
21, 22, 23, 24, 25, 26) are formed. As is clear from FIG. 2(a), for example, the right terminal group (2
1 to 23) are connected to the terminal group V, R of the strain gauge of the flexure element 1 located on the right side, and similarly to the terminal group on the left side (24 to 2
6) shows the terminal group V of the strain gauge of the strain body 1 located on the left side.
, R are connected. In addition, although the thin part 11 is formed only on the left side of the wiring processing thin plate 2 in the illustrated example, the thick part 12
It is also possible to protrude from both sides of the thin plate 2 for wiring processing, and to provide the thin portions 11 on both the left and right sides of the thin plate 2 for wiring processing. That is, it is also possible to extend the thin wall portion 11 to the center of the thick wall portion 12.

Preferably, an appropriate number of through holes 14, for example three, are formed in the thin portion 11, and each connection lead wire group 9 including the power supply lead wire 7 is connected to the thin plate 2 for wiring processing through these through holes. Take it out on one side (the left side in the example shown),
From there, they can be connected together to an amplifier (not shown) or a power source (indicated by +E, -E). In FIGS. 2(B) and 2(C), the blacked-out portions indicate the solder deposits connecting the lead wires and the terminal group.

By providing the terminal group on the thin wall portion 11 of the wiring processing thin plate 2, it is possible to prevent the terminal group, lead wires, or solder deposits from coming into direct contact with the adjacent strain-generating body. or,
After connecting the terminal group and the lead wires, by applying a fixing agent or a moisture-proofing agent to the entire thin wall portion 11 as shown by the imaginary line 20 in FIG. It is possible to prevent contact short circuits or electrical leakage due to moisture.

FIG. 3 schematically shows an equivalent Wheatstone bridge circuit of a strain gauge. In the same figure, subscripts a1, a
2..., y1, y2..., x1, x2..., c1
, c2..., b1, b2..., 21, 22... indicate the correspondence with the terminal groups and lead wires in FIGS.

[0017]

[Effects of the Invention] As described above, according to the present invention, the thin plate for wiring processing is sandwiched between any two sheets in the strain-generating body, so that lead wires can be processed in a concentrated manner. There is no need to secure a space for providing a group of terminals for handling lead wires on the strain-generating body, and therefore, the force detector can be downsized. In addition, by connecting the terminal groups formed on both sides of the thin plate for wiring processing to the strain gauges of the adjacent strain bodies located on the respective corresponding sides, the lead wires (wiring) can be connected to the outer periphery of the thin plate for wiring processing. None exist. In other words, it is possible to avoid routing lead wires.

Furthermore, by providing a reinforcing part (thick part) for connection and fixing to the strain-generating body on the outer periphery of the thin plate for wiring processing,
It is possible to concentrate the terminal group and its connecting portion group in the thin wall portion located inside the terminal, and furthermore, it is possible to protect these by coating them entirely with a fixing agent or a moisture-proofing agent. Furthermore, since the wiring can be intensively taken out on one side of the thin plate through the through holes formed in the wiring processing thin plate, wiring work can be easily performed on only one side.

[Brief explanation of drawings]

FIG. 1 is a lower half cross-sectional front view showing an overview of the entire force detector to which a wiring processing device according to the present invention is applied.

FIG. 2 is a front view and left and right side views of the thin plate for wiring processing according to the present invention.

FIG. 3 is an equivalent Wheatstone bridge circuit diagram of the strain gauge of the flexure element shown in FIG. 1;

[Explanation of symbols]

1, 3, 4...Strain body 2...Thin plate for wiring processing 9...Lead wire

Claims (4)

[Claims] Claim 1: In a multi-axis force detector in which a plurality of strain bodies (1, 3, 4) connected in series are laminated, each having a strain gauge, wiring processing is performed between any two strain bodies. A group of terminals (21, 22, 2) to which the lead wires (9) of the strain gauge are to be connected to the thin plate (2) for wiring
3, 24, 25, 26). [Claim 2] The thin plate for wiring processing has terminal groups on both sides thereof, and these terminal groups are connected via lead wires to strain gauges of strain-generating bodies located on the sides of the respective surfaces. The wiring processing device according to claim 1. 3. The thin plate for wiring processing has a thick wall portion (12) in the outer circumferential portion located outside the terminal group, and in the thick portion, each strain-generating body located on both sides of the thin plate for wiring processing The wiring processing device according to claim 1, wherein the wiring processing device is fixed to. 4. The thin plate for wiring processing has a group of terminals in the thin plate part (11) surrounded by the thick part, and these terminal groups are connected to the strain gauge of the corresponding strain body through lead wires. The wiring processing device according to claim 3, characterized in that the thin plate portion is coated with a fixing agent (20) or a moisture-proofing agent (20) applied to the thin plate portion.