JPH0684335U - Load detector - Google Patents

Abstract

(57) [Summary] [Object] To provide a load detector that can be downsized and that does not cause a measurement error even when a force in a different direction other than the load to be measured is applied to the load detection rod 3. [Structure] A load detecting rod 3 having an action portion 3a on the front side is fixed to a surface of an elastic plate (leaf spring 1) on its side surface, and elastic plates are fixed to stationary elements (case 5) on both sides of the load detecting rod 3. A hinge body (bending leaf spring 2) is provided on the stationary element at a position rearward of the acting portion 3a of the load detecting rod 3 at a right angle to the load detecting rod 3 and on the same plane as or parallel to the elastic plate and the load is applied to the hinge body tilting portion. A strain member which is formed by connecting the detection rods 3 and receives the load to be detected in the acting portion 3a of the load detection rod 3 in a direction perpendicular to the elastic plate;
The tilt axis of the hinge body due to the load to be detected (bending side 2
It is composed of a position sensor (semiconductor position detector 6) for measuring the tilting displacement of the load detecting rod 3 around a) at the detecting portion 3b thereof.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a load detector for detecting a load based on tension or the like.

[0002]

[Prior art]

 As a load detector, Japanese Unexamined Patent Publication (Kokai) No. 60-173435 and Japanese Utility Model Laid-Open No. 62-133139 disclose a pair of parallel elastic members having a movable rigid side portion in parallel with a fixed rigid side portion fixed to a stationary element. A rectangular strain member that is connected via a side part and receives the load to be detected in the direction of the side by the movable rigid side part, and the displacement in the side direction of the movable rigid side part due to the load to be detected is measured. What comprises a position sensor is disclosed.

In this detector, although highly accurate load measurement is possible, when the strain member becomes small to some extent, the position sensor cannot be placed in the rectangular frame of the strain member, which hinders miniaturization. There is a problem that it becomes difficult to incorporate into a micromachine.

On the other hand, Japanese Patent Laid-Open No. 63-279133 discloses a yarn tension measuring device in which a load detecting rod is vertically attached to a leaf spring whose both ends are fixed. The leaf spring is twisted according to the tension applied to the acting portion of the load detecting rod which is in sliding contact with the load detecting rod at a right angle thereto, and the displacement of the detecting portion of the load detecting rod caused by the twist is measured.

This measuring device can be easily miniaturized, but when the action part of the load detection rod receives a force in the running direction due to the running resistance of the yarn, it is also easily displaced in that direction and the detecting part. However, there was a problem in that the original tension measurement was erroneous due to the displacement of the detection position due to displacement in the opposite direction.

[0006]

[Problems to be solved by the device]

 An object of the present invention is to provide a load detector that can be downsized and that does not cause a measurement error even when a force in a different direction other than the load to be measured is applied to the load detection rod.

[0007]

[Means for Solving the Problems]

 In the load detector according to the present invention, a load detecting rod having a front acting portion is fixed to the elastic plate surface at its side surface, and the elastic plates are fixed to stationary elements on both sides of the load detecting rod. At the position behind the action part, the hinge body is provided on the stationary element at right angles to the load detection rod and on the same plane as or parallel to the elastic plate, and the load detection rod is connected to the hinge body tilting part to detect the load to be detected. The strain member that receives the elastic plate in the direction perpendicular to the elastic plate at the action part of the load detection rod, and the tilt displacement of the load detection rod around the tilt axis of the hinge body due to the detected load are measured at the detection part. It consists of a position sensor.

The hinge body can be tilted only in a plane perpendicular to the tilt axis, and preferably has no sliding portion for detecting a minute load. For example, a leaf spring is bent in an L shape. In addition, it is possible to suitably use the one whose bending side is the tilt axis.

In addition, the acting portion of the load detecting rod is projected forward from the elastic plate, and the detecting portion of the load detecting rod is projected rearward from the elastic plate and the hinge body so that the detecting portion of the load detecting rod and the stationary element are connected. A position sensor may be interposed between them, and if necessary, from a stationary element on both sides of the load detection rod provided so that the acting part receives the tension as a load to be detected by sliding contact with the tension measurement object. A pair of guide rods may be extended so that the tension measurement target is guided in a triangular shape at each action portion on the load detection rod and the guide rod.

[0010]

[Action]

 In the load detector configured as described above, when a load to be detected is applied to the action portion of the load detection rod in a direction perpendicular to the elastic plate, the load detection rod is centered on the tilt axis of the hinge body in a size corresponding to the load to be detected. As a result, the displacement of the elastic plate is performed together with the displacement of the elastic plate, and the displacement of the displacement is measured by the position sensor in the detection unit of the load detection rod. In the strain member used in this load detector, the load detection rod is connected to the hinge body at a right angle and is fixed to the surface of the elastic plate at its side surface, so that it has elasticity only in the direction perpendicular to the elastic plate. The position of the hinge body may be on the elastic plate or in front of or behind the elastic plate, as required.

In the case where the operating portion and the detecting portion of the load detecting rod are projected forward and rearward from the elastic plate and the elastic plate and the hinge body, respectively, the operating portion and the detecting portion are centered on the tilt axis of the hinge body. Tilt displacements are made in opposite directions, and in this case, the acting portion of the load detecting rod, the strain member, and the detecting portion of the load detecting rod are sequentially arranged along the axis of the load detecting rod.

Further, in a device provided with a load detection rod and a guide rod for tension detection, a tape or other tension measurement object is slidably contacted with an action portion of the load detection rod, and the action portion and the action portion of each guide rod are Is guided in a triangular shape, and the tilt displacement of the detection portion of the load detection rod caused by the tension under the state is detected by the position sensor as described above and the tension is calculated. By allowing the guide rod to change its angle with respect to the load detection rod, the inclination angle of the guide rod with respect to the load detection rod can be temporarily enlarged during sliding contact between the tension measurement target and the load detection rod so that the distance between the two members is increased. It is possible to easily load the tension measurement target into the. Each of the acting portions on the load detecting rod and the guide rod may be provided with a rotatable roller.

[0013]

【Example】

 FIG. 1 is a perspective view of a load detector according to an embodiment of the present invention, which is configured to detect tension.

In FIG. 1, the leaf spring 1 and the bent leaf spring 2 which is arranged on the same plane behind the leaf spring 1 and whose rear portion is bent in an L-shape are provided with bent sides of the bent leaf spring 2. A load detection rod 3 and connecting rods 4 are fixed to each side surface at a right angle to 2a and parallel to the load detection rod 3, and a rear end of each connecting rod 4 is connected to an end face of a case 5 which is a stationary element. The leaf spring 1 acts as an elastic plate, the bent leaf spring 2 acts as a hinge body having the bending side 2a as a tilt axis, and the leaf spring 1, the bent leaf spring 2, the load detection rod 3 and the connecting rod 4 are Together to form the strain member. The leaf spring 1 may be replaced with a rubber plate or other elastic plate, if necessary.

The load detecting rod 3 is extended to the front of the leaf spring 1 and to the rear of the bent leaf spring 2, respectively, and the rear end of the load detecting rod 3 is divided into a split groove 5a (partly) on the end face of the case 5. It is installed contactlessly in the notch). The front end of the load detecting rod 3 is used as a working portion 3a for loading the load to be detected, and the rear end of the load detecting rod 3 is used as a detecting portion 3b for measuring tilt displacement, and the dividing groove between the detecting portion 3b and the end surface of the case 5 is used. A light emitting portion 6a and a light receiving portion 6b, which form a semiconductor position detector 6 as a position sensor, are arranged on the bottom of 5a so as to face each other in the direction of the load detecting rod 3. A guide rod 7 extends forward from each connecting rod 4 in parallel with the load detecting rod 3, and each front end of the guide rod 7 is used for guiding as an action portion 7a.

In the above-mentioned structure, the tape 8 which is the tension measurement object is slidably contacted with the acting portion 3a of the load detecting rod 3 and is guided in a triangular shape by the acting portion 3a and each acting portion 7a on the guide rod 7. In that state, the acting portion 3a of the load detecting rod 3 receives a tension and tilts together with the displacement portion of the leaf spring 1 about the bending side 2a, and at the same time, the detecting portion 3b tilts and displaces in the opposite direction. The tension is measured while being measured by the position detector 6. In the above configuration, the bent leaf spring 2 can also act as an elastic plate, but the bent leaf spring 2 displacement portion is closer to the bending side 2a, which is the tilt axis of the hinge body, than the leaf spring 1, so that load detection can be performed. The effect on it is ignored.

It should be noted that, in the above-mentioned embodiment, the guide rods 7 excluded can be suitably used as a normal load detector, for example, for load detection in a narrow gap or the like.

Next, FIG. 2 is a perspective view of a load detector according to another embodiment of the present invention. In the embodiment shown in the figure, the design of the embodiment shown in FIG. 1 is partially modified, and the bent leaf spring 2 as a hinge is moved forward to be integrated with the leaf spring 1 as an elastic plate. Accordingly, the rear end of the load detection rod 3 is advanced to the front of the end face of the case 5 integrally with the light emitting part 6a of the semiconductor position detector 6, and the split groove 5a on the end face of the case 5 is eliminated, so that the light receiving part 6b of the semiconductor position detector 6 is removed. Is arranged directly on the end surface of the case 5.

Note that the configuration and effects other than those described above in the present embodiment are the same as those of the embodiment shown in FIG. 1, so description thereof will be omitted.

[0020]

[Effect of device]

 Since the load detector according to the present invention is configured as described above, it can be downsized, and even if a force in a different direction other than the load to be measured is applied to the load detection rod, no measurement error occurs. It can also be suitably used for measuring tension.

[Brief description of drawings]

FIG. 1 is a perspective view of a load detector according to an embodiment of the present invention.

FIG. 2 is a perspective view of a load detector according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 leaf spring 2 bent leaf spring 2a bent side 3 load detecting rod 3a acting portion 3b detecting portion 5 case 6 semiconductor position detector

Claims (4)

[Scope of utility model registration request] 1. A load detection rod having a front acting portion is fixed to a surface of an elastic plate at a side surface thereof, and elastic plates are fixed to stationary elements on both sides of the load detecting rod, and a position behind the acting portion of the load detecting rod. At a right angle to the load detection rod and on the same plane as the elastic plate or in parallel with the elastic plate, the hinge body is provided on the stationary element and the load detection rod is connected to the hinge body tilting portion, and the load to be detected is applied to the action portion of the load detection rod. A load detector including a strain member adapted to be received in a direction perpendicular to an elastic plate, and a position sensor for measuring a tilt displacement of a load detection rod centered on a tilt axis of a hinge body by a load to be detected at a detection portion thereof. 2. The load detector according to claim 1, wherein the hinge body bends the leaf spring into an L-shape, and the bent side is a tilt axis. 3. The load detecting rod has an acting portion projecting forward from the elastic plate and a detecting portion of the load detecting rod projecting rearward from the elastic plate and the hinge body so as to be located between the detecting portion of the load detecting rod and the stationary element. The load detector according to claim 1, wherein a position sensor is interposed in the load detector. 4. A pair of guide rods are extended from stationary elements on both sides of a load detection rod provided so that the acting portion receives tension as a load to be detected by sliding contact with a tension measurement target, and the load detection rod and The load detector according to claim 3, wherein a tension measurement target is guided in a triangular shape at each of the action portions on the guide rod.