JP2008209149A - Device for measuring lid opening operating force of iron lids - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure a lid opening operating force in the same manner as lid opening operation using a lid opening tool. <P>SOLUTION: A device measures the operating force required for removing iron lids biting into a receiving frame from the receiving frame by lever action using the lid opening tool. The device includes the bar-like lid opening tool 13 having a lever element where the base end is used as a power source for applying the operating force, the tip is used as an action point for acting on the iron lids 12 and forcing the iron lids open, and the proximity of the action point is used as a fulcrum for making the receiving frame support the lid opening tool, a sensor 20 that is attached to the tool body and detects a minute amount of deformation occurring in the lid opening tool when the lever element is arranged at each position of the lid opening tool and the operating force applied to the power point is made to act on the action point, and a display section 14 that calculates the bending stress generated in the lid opening tool by the lid opening operation based on the output value of the sensor, and displays the operating force as a physical quantity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring the operating force required when iron lids biting into a receiving frame are removed from the receiving frame by lever action using a lid opening tool.

  There is a so-called steep slope type of manhole iron cover having an outer peripheral surface formed in a tapered shape, and the tapered outer peripheral surface is fitted to the tapered inner peripheral surface of the receiving frame. Such an iron lid is characterized by being able to contain rattling due to a steeply tapered surface that has been processed, but in recent years the weight of vehicles has increased, and the iron lid has bite into the receiving frame and is difficult to open. The problem has arisen. If the operating force required for opening the lid is excessive, the physical burden increases and also an extra time is consumed. For example, in the case of a fire hydrant lid, the fire extinguishing activity is accordingly increased. For this reason, it is necessary to know in advance how much operating force is required to open the iron cover that has been bitten.

  However, there is no measuring device that can be used for the above purpose. On the other hand, conventionally, when performing a lid opening operation using a bar-shaped opening tool commonly called a bar or the like, it was also performed by attaching only a spring to the operation part, It was dangerous because the numerical values varied and it was difficult to be accurate, and the springs could come off. Due to such circumstances, the present inventor has developed and completed the present invention with the intention of measuring the opening operation force using an opening tool as in the actual opening operation. .

Utility model registration No. 3109108

  The present invention has been made paying attention to the above-mentioned points, and the object thereof is to provide an apparatus for measuring the opening operation force of iron lids using an opening tool. Another object of the present invention is to make it possible to measure the opening operation force in the same manner as when the opening operation is actually performed using the opening tool.

  In order to solve the above-mentioned problem, the present invention is an apparatus for measuring the operating force required when removing iron lids biting into the receiving frame from the receiving frame by lever action using an opening tool. The base element is the point that applies operating force, the tip part acts on the iron lids and acts as an action point that opens the iron lids, and the lever element that supports the opening tool on the receiving frame near the action point A small amount of deformation that occurs in the opening tool when the lever-shaped opening tool with the above-mentioned lever element and the above-mentioned lever element of the opening tool are arranged at the respective positions and the operating force applied to the power point is applied to the action point In order to detect this, a sensor attached to the tool body and a display unit that calculates the bending stress generated in the opening tool by the opening operation based on the output value of the sensor and displays the operation force as a physical quantity. Take measures to provide and configure Those with (claim 1).

  The apparatus which concerns on this invention is an apparatus for measuring the operating force required when the iron lids which bite into the receiving frame are removed from a receiving frame by lever action using an opening tool. There is a so-called steep slope type structure in which the taper outer peripheral surface of the iron cover is fitted to the taper inner peripheral surface of the receiving frame. Of course, the invention can be applied when measuring the removal force of the iron lids in this type, but is not limited to the taper fitting lid, and any type of iron lids fitted in the receiving frame in any form. It can be applied to the measurement of opening operation force.

  In the apparatus according to the present invention, first, the base end portion is a force point for applying an operating force, and the tip end portion is an action point for opening the iron lids by acting on the iron lids, and the cover frame is opened near the action point. There is a need for a bar-shaped opening tool with a lever element that serves as a fulcrum for supporting the tool. Needless to say, the power point is a place where a person engaged in the work applies a force for opening the lid, and the action point is a place where the opening force of the opening tool is applied to the iron lids.

  The lid opening tool has a locking portion at the tip and a handle at the base end, and various protrusions around the locking portion at the tip are necessary for opening the iron lids. Is provided. A latching | locking part is a part which latches and opens a lid opening tool on iron lids. Further, the protrusion has a portion provided at the rear so as to be in contact with the receiving frame and serving as a fulcrum, and a portion extending to the left and right of the tool body so as to be in contact with the surface or the bottom surface of the iron lids to improve stability. It is desirable that it is (the invention according to claim 2). In addition, although the handle | steering-wheel provided in an opening tool has a substantially T shape and a thing which becomes a cross shape (FIG. 1, FIG. 2, etc.), the handle | steering_wheel in this invention includes both.

  By using the lid opening tool configured as described above, the operating force applied to the power point can be applied to the iron lids as an action force necessary for opening the lid, that is, an opening force, in a substantially constant direction. The force applied to the sensor attached to the opening tool is almost constant. When the above-mentioned lever elements of the opening tool are arranged at the respective positions, and the operation force applied to the force point is applied to the action point, the sensor is attached to the place where the slight deformation amount generated in the opening tool is maximized. This is a desirable configuration because the direction of input to the sensor becomes constant through the opening operation by lever action. That is, the opening force with respect to the iron lids by the opening tool is substantially constant, and the deformation amount transmitted to the sensor is also substantially constant.

  When the opening tool is in the shape of a round bar with a circular cross section, when the lever element is arranged at each position, a flat surface is formed at one or both of the upper surface position and the lower surface position. In addition, a configuration in which a sensor is attached to this plane can be employed (the invention according to claim 3). The position that becomes the upper surface is a place where the above-described minute deformation amount becomes the maximum as the tensile force, and the position that becomes the lower surface is the place where the minute deformation amount becomes the maximum as the compressive force. Note that there is little need to form a flat surface in the case of an open tool in which a flat surface is arranged on the upper surface or the lower surface, such as a square cross section. A flat surface for mounting the sensor shall be provided.

  The sensor is attached to the tool body and detects a slight deformation amount generated in the opening tool. More specifically, the sensor is arranged such that when the above-mentioned lever elements of the opening tool are arranged at the respective positions and the operating force applied to the force point is applied to the action point, the elasticity of the rod-like opening tool. For example, a strain sensor (also referred to as a strain gauge) or the like can be used. The strain sensor (strain gauge) is used to capture the local length change caused by the elastic deformation of the opening tool when opening the lid via the Wheatstone bridge and measure the amount of deformation. It can be displayed by replacing with physical quantities such as stress, pressure and external force.

  Therefore, a display unit is combined with the sensor in order to calculate the bending stress generated in the opening tool by the opening operation based on the output value of the sensor and display the operation force as a physical quantity. The display unit includes a storage device, an arithmetic device, a display device, and the like, but can also be connected to a PC (personal computer) to perform various data management. In addition, a display part is divided roughly into what is provided separately from a lid opening tool, and what is provided integrally.

  Since the present invention is configured and operates as described above, the operation force necessary for removing from the receiving frame by the lever action using the opening tool is actually opened using the opening tool. In the same manner as the operation, there is an effect that the measurement can be performed directly in the same manner as the actual opening operation. Further, according to the present invention, in addition to being able to know in advance the opening force of iron lids such as fire hydrant iron lids, which must be opened urgently, for example, local governments and other underground structures Even the administrator can accurately grasp the force required to open the manhole cover used in the underground structure.

  Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments. FIG. 1 shows an iron lid according to the present invention for measuring the operating force required when the iron lids 12 biting into the receiving frame 11 are removed from the receiving frame 11 by lever action using an opening tool 13. 1 shows an example of a measuring device 10 for the kind of lid opening operation force. FIG. 1A shows an example in which the display unit 14 is provided separately from the opening tool 13, and FIG. 1B shows an example in which the display unit 14 is provided integrally. Except for the point that the display unit 14 is provided separately or integrally, the configuration as the invention is the same, so the following description will be made without particularly distinguishing whether it is separate or integrated.

  Referring to FIGS. 2 and 3, the lid opening tool 13 has a force point 15 at which the base end portion applies an operating force, and a tip end portion that acts on the iron lids 12 to be plucked open. It is a rod-shaped object having a lever element in which a supporting point 16 is a point at which the opening frame 13 is supported by the receiving frame 11 in the vicinity. The opening tool 13 has a hook-shaped locking portion 18 at the tip, and a handle 19 constituting a substantially cross shape at the base end. Further, a twisting portion 18a is formed at the base end protruding from the handle, a support projection 18b is formed on the rear side of the distal end portion, and a pressing projection 18c is formed on the left and right side portions, respectively. The locking portion 18 is inserted into a so-called burl hole 12a of the iron lid 12 to be in a locked state, the indicating projection 18b comes into contact with the upper end of the receiving frame 11 and becomes a fulcrum, and the pressing projection 18c is an iron lid. Contact the top surface of the species.

  FIG. 4 shows another example of a lid opening tool 13 ′, which has a substantially T-shaped locking portion 18 ′ in contact with the lower surface of the iron lid 12 at the tip. A support protrusion 18d is provided on the rear side. The substantially T-shaped locking portion 18 'is formed in parallel with the handle 19'. For other configurations, the same reference numerals as those in FIGS. 2 and 3 are used, and detailed description thereof is omitted. 2, 3, or 4, the lid is opened by the lever action determined according to the ratio of the length A from the fulcrum 16 to the force point 15 and the length B from the fulcrum 16 to the action point 17. Will work.

  The opening tool 13, 13 'has a small amount generated in the opening tool 13, 13' when the above-mentioned lever elements are arranged at the respective positions and the operating force applied to the force point 15 is applied to the action point 17. In order to detect the amount of deformation, a strain sensor 20 is attached (FIGS. 2 to 7). In the example shown in FIG. 5, when the opening tools 13, 13 'having a round bar shape with a circular cross section are arranged at the respective positions, both the upper surface position and the lower surface position are symmetrical as shown in FIG. The planes 21 and 22 are formed, and two sensors 20-1, 20-2, 20-3, and 20-4 are attached to the planes 21 and 22, respectively, as shown in FIG. The lead wires of the upper sensors 20-1 and 20-2 are pulled out to the left and right sides, the lead wires of the lower sensors 20-3 and 20-4 are connected to the terminal block 23, and another lead wire is connected from the terminal block 23. Pull out. The sensors 20-1... Are attached to the planes 21 and 22 by adhesion.

  As shown in FIG. 7, each sensor portion is protected by being covered with, for example, a resin cover 24, and is connected to the display unit 14 by a cord 25. The four strain sensors 20-1, 20-2, 20-3, 20-4 are connected as resistors constituting the Wheatstone bridge circuit 26 as shown in FIG. The display unit 14 calculates the bending stress generated in the opening tool 13, 13 'by the opening operation based on the output value of the sensors 20-1,... And displays the operation force as a physical quantity. There is a choice as to whether this is provided integrally with the opening tool 13, 13 'or provided separately, as already described in FIGS. 1A and 1B.

  As shown in FIG. 10, the display unit 14 includes a power supply circuit that supplies a voltage to the strain sensor, an amplification circuit that amplifies the differential voltage output from the Wheatstone bridge circuit 26, and an A / D that converts the output signal from the strain sensor into a digital signal. A D conversion circuit, an arithmetic circuit that converts (converts) a digital signal into an ability, and a display circuit that outputs an arithmetic result as a physical quantity.

  In such a configuration, in order to open the iron lids that bite into the receiving frame, the tips of the opening tools 13, 13 'are inserted into the so-called bar holes 12a of the iron lids 12, and the locking portions 18, 18 thereof. 'Is hung on the back surface of the lid close to the edge of the burl hole 12a and stabilized, and the operation is applied by applying an operating force with the upper end corner of the receiving frame as a fulcrum and the base end as a force point 15 (Fig. 1, (See FIG. 3). As the iron lid 12 starts to be opened by the opening force proportional to the operation force, the deformation amount of the opening tools 13, 13 'increases, and at the moment when the iron lid 12 is opened, the deformation amount is It is detected by the strain sensors 20-1, 20-2, 20-3, and 20-4. The detected value is output to the display unit 14 via the code 25, the peak value is held, and the acting force required for opening is displayed on the display unit 14, for example, in units of Newton (N).

  About the opening tool for opening the manhole iron lid which is a kind of iron lid, 800 mm is generally adopted as the length A from the fulcrum 16 to the force point 15. Therefore, the opening force necessary for opening the lid, which is applied and examined as shown in FIG. 9, will be described next.

As an example, a φ500 fire hydrant iron lid and a φ600 fire hydrant iron lid are to be inspected, and as shown in FIG. 1, the iron lids 12 subjected to the inspection are fitted to the receiving frame 11, and further, a load tester Was used to cause biting at a predetermined test load. The test load was 210 kN (T-25 specified in the road bridge specifications, total vehicle weight = 25 tons), and the opening force by the apparatus 10 according to the present invention was measured. as a result,
In the case of a fire hydrant iron cover for φ500,
The opening force by the separate apparatus shown in FIG. 1A is displayed as 397N.
For φ600 fire hydrant iron cover,
The opening force by the separate apparatus shown in FIG. 1A is displayed as 298N.

  Therefore, in the case of a fire hydrant iron cover for φ500, an opening force of about 397 N, that is, about 40.5 kg is required, and in the case of a fire hydrant iron cover for φ600, an operation opening force of about 298 N, that is, about 30.4 kg, is required. I understand that In addition, as a numerical value displayed on the display part 14, arbitrary physical quantities, such as stress, pressure, and external force, can be selected as mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus for measuring the opening operation force of iron lids according to the present invention, in which A has a separate display unit and B has an integrated display unit. The example of the opening tool used for the apparatus which concerns on this invention which has an integrated display part is shown, A is a front view, B is a side view. The use state of an opening tool same as the above is shown, A is sectional explanatory drawing which shows an insulator action, B is a top view. Similarly, another example of the opening tool is shown, in which A is a front view and B is a side view. The sensor mounting part is shown, with A being a side view, B being a plan view, and C being a cross-sectional view. The sensor is shown attached, A is a top view, B is a side view, and C is a bottom view. It is sectional explanatory drawing which similarly shows a sensor attachment state. The circuit explanatory drawing of a Wheatstone bridge. It is the whole side view explaining the example of an experiment of the acting force required for lid opening operation by the device concerning the present invention. 1 shows an electrical configuration of an apparatus according to the present invention, in which A is a side view and B is a circuit diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Measuring apparatus of opening operation force of iron lids 11 Receiving frame 12 Iron lids 13, 13 'Opening tool 14 Display part 15 Power point 16 Support point 17 Action point 18, 18' Locking part 19, 19 'Handle 20, 20 -1 to 20-4 Strain sensor 21 Plane 22 Plane 23 Terminal block 24 Cover 25 Cord 26 Wheatstone bridge

Claims (3)

A device for measuring the operating force required when removing the iron lids biting into the receiving frame from the receiving frame by lever action using an opening tool,
The base element is the point that applies operating force, the tip part acts on the iron lids and acts as an action point that opens the iron lids, and the lever element that supports the opening tool on the receiving frame near the action point A rod-shaped opening tool having
In order to detect the slight amount of deformation that occurs in the opening tool when the above-mentioned lever element of the opening tool is placed at each position and the operating force applied to the force point is applied to the action point, Attached sensor,
Based on the output value of the sensor, the bending stress generated in the opening tool by the opening operation is calculated, and the opening operation force of the iron lids configured to display the above operation force as a physical quantity Measuring device. The lid opening tool has a locking portion at the tip and a handle at the base end, and various protrusions around the locking portion at the tip are necessary for opening the iron lids. The projecting part is a part provided at the rear so as to be in contact with the receiving frame and serving as a fulcrum, and a part extending to the left and right of the tool body so as to be in contact with the surface or lower surface of the iron lid The apparatus for measuring the opening operation force of iron lids according to claim 1. The opening tool is in the shape of a round bar with a circular cross section, and when the lever element is disposed at each position, a flat surface is formed at one or both of the position that becomes the upper surface and the position that becomes the lower surface, The apparatus for measuring the opening operation force of iron lids according to claim 1 or 2, wherein a sensor is attached to the plane.

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