JP2012185060A - Weight measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure weight of a drum can 8 by an air cylinder 9.SOLUTION: In the case that a solenoid valve 17 is switched from a discharge state to an injection state, injection of detection air is started from an air pump 11 through a regulator 14 and a speed controller 16 to an air cylinder 9. In the case that the injection of the detection air to the air cylinder 9 is started, an inner pressure of the air cylinder 9 rises from the atmospheric pressure drawing a straight line rising diagonally up and to the right relative to the lapse of time. In the case that the inner pressure of the air cylinder 9 becomes a size corresponding to the weight of a drum can 8, a lever 4 is rotated counterclockwise from a reference position. When the lever 4 is rotated counterclockwise from the reference position, an electric state of an atmospheric relay 19 changes. When the electric state of the atmospheric relay 19 changes, a control circuit detects a pressure signal from a pressure sensor 18 as the weight of the drum can 8.

Description

  The present invention relates to a weight measuring apparatus that measures the weight of a measurement object using a cylinder.

  Some weight measuring devices include an air cylinder and a measuring table. The measuring table is for placing a measurement object, and is stationary at the reference position while the piston rod of the air cylinder is stationary at the initial position. In this air cylinder, air of constant pressure is injected from an air supply source through a regulator, and when the weight of the measurement object is below the threshold value, the measuring table is pushed from the reference position by being pushed by the piston rod of the air cylinder. When the measurement table moves beyond a certain amount and the measurement table moves beyond a certain amount, the alarm is activated to notify the operator that the weight of the measurement object is too small.

Japanese Utility Model Publication No. 6-4325

  The weight measurement device notifies the operator whether or not the weight of the measurement object is too small, and cannot notify the operator of the magnitude of the weight of the measurement object.

  The weight measuring device of the present invention includes a fluid source for discharging fluid, a regulator for adjusting the pressure of the fluid discharged from the fluid source, a flow valve for adjusting the flow rate of the fluid regulated by the regulator, and a cylinder A cylinder having a tube and a piston rod; “1A) a first state in which the inside of the cylinder tube is opened” and “2A) a state in which the inside of the cylinder tube is closed, and the regulator and the flow valve are A control valve that is switched to each of the “second state in which pressure is applied to the piston rod by injecting fluid into the cylinder tube through each of the cylinder tubes and a measurement object for measuring the weight” are mounted. 1B) The control valve is stationary at a certain reference position in the first state ”and“ 2B) the control valve is the first When the state is switched from the second state to the second state, the cylinder tube is pushed by the piston rod in response to the pressure corresponding to the weight of the measurement object, and moves from the reference position. A switch that changes an electrical state depending on whether or not the lever is in the reference position, a pressure sensor that outputs a pressure signal corresponding to the pressure in the cylinder tube, and the lever A detection circuit configured to detect a pressure signal from the pressure sensor when the electrical state of the switch changes due to movement from a reference position; and the flow valve is configured to measure the lever at the reference position of the lever. When the control valve is switched from the first state to the second state while an object is placed, the pressure in the cylinder tube changes from the reference value over time. Characterized in place of adjusting the flow rate of the regulator pressure adjusted fluid to rise in a linear relative.

  When the control valve is switched from the first state to the second state, fluid starts to be injected into the cylinder tube from the fluid source through the regulator and the flow valve, and fluid is started to be injected into the cylinder tube. The pressure in the cylinder tube rises linearly with the passage of time from the reference value. When the pressure in the cylinder tube reaches a level corresponding to the weight of the object to be measured, the lever moves from the reference position with the pressure in the cylinder tube, and when the lever moves from the reference position, the switch electrical When the state changes and the electrical state of the switch changes, the detection circuit detects the pressure signal from the pressure sensor. The detection result of the pressure signal corresponds to the pressure in the cylinder tube when the lever moves from the reference position against the weight of the measurement object, and the weight of the measurement object is detected as a pressure signal.

The figure which shows Example 1 (The figure which shows the mechanical structure of a weight measuring device) Diagram showing the electrical configuration of the weight measuring device Flow chart showing weight measurement process of control circuit Diagram showing the pressure rise state of the air cylinder The figure which shows Example 2 (figure 1 equivalent figure)

  A floor surface 1 in FIG. 1 is horizontal, and a detection table 2 is fixed to the floor surface 1. The detection table 2 has a hollow box shape and has a placement surface 3 that is horizontal to the floor surface 1. A lever 4 is mounted on the detection table 2. The lever 4 is rotatable about a horizontal shaft 5 and has a placement surface 6 and an operation surface 7. The lever 4 comes to rest at the reference position by contacting the stopper. At the reference position of the lever 4, the placement surface 6 and the operation surface 7 are in a horizontal state, and the placement surface 6 is in a horizontal state. Thus, it is arranged on the same horizontal plane as the mounting surface 3 of the detection table 2. A part of the drum can 8 is placed on the mounting surface 3 of the detection table 2. The drum can 8 stores liquid paint, and the remaining remaining portion of the drum can 8 except for a part placed on the placement surface 3 of the detection table 2 is placed on the placement surface 6 of the lever 4. The drum 8 corresponds to a measurement object.

  As shown in FIG. 1, an air cylinder 9 is fixed in the detection table 2. The air cylinder 9 has a cylinder tube, a piston, and a piston rod. The cylinder tube is directed in a vertical direction perpendicular to the mounting surface 3 of the detection table 2, and the piston moves in the vertical direction in the cylinder tube. Inserted as possible. The piston rod is fixed to the piston and has a cylindrical shape coaxial with the cylinder tube. The air cylinder 9 has a pressure chamber. This pressure chamber is a sealed space surrounded by the cylinder tube and the piston, and the piston rod stops at the initial position when the pressure chamber is at atmospheric pressure. At the initial position of the piston rod, the upper end surface of the piston rod is the lever. 5 is brought into contact with the operation surface 7 from below. At the initial position of the piston rod, the operating force from the bottom to the top does not act on the operating surface 7 from the piston rod, and the lever 4 stops at the reference position. The air cylinder 9 corresponds to a cylinder.

  As shown in FIG. 1, the air cylinder 9 has an inlet and an outlet. The inlet is for injecting air into the pressure chamber, and the piston rod rises with the piston when air is injected into the pressure chamber. The discharge port discharges air from the pressure chamber, and the piston rod descends together with the piston as air is discharged from the pressure chamber. This piston rod pushes the operation surface 7 of the lever 4 from the bottom to the top when the piston rod is lifted from the initial position at the reference position of the lever 4. The lever 4 is the reference position of the lever 4 and the operation surface 7 is moved from the bottom. When it is pushed upward, it rotates counterclockwise around the shaft 5.

  As shown in FIG. 1, a push button valve 10 is fixed to the detection table 2. The push button valve 10 has a push button and a return spring, and the push button is movable in the vertical direction between the open position above the closed position and the closed position. The push button is such that the weight of the lever 4 acts through the operation surface 7 at the reference position of the lever 4, and the weight of the lever 4 stops at the closed position against the spring force of the return spring. When the lever 4 is rotated counterclockwise from the reference position, the operation surface 7 of the lever 4 is separated. When the lever 4 is rotated counterclockwise from the reference position, the push button is pressed. Rises to the open position by the spring force of the return spring. The push button valve 10 has an inlet and an outlet, and is in an open state in which air can pass from the inlet to the outlet at the push button open position, and in a closed state in which air cannot pass at the push button closed position. Become.

  As shown in FIG. 1, an air pump 11 is installed on the floor surface 1. The air pump 11 is driven by a pump motor and has an inlet and an outlet. The air pump 11 sucks air into the inlet when the pump motor is in operation, and the air sucked into the air pump 11 is discharged from the outlet. The air pump 11 corresponds to a fluid source. The outlet of the air pump 11 is connected to the inlet of the gate valve 12 via a pipe, and the air discharged from the outlet of the air pump 11 is supplied to the inlet of the gate valve 12. The gate valve 12 has an inlet and an outlet, and is mechanically switched between an open state where the air supplied to the inlet is discharged from the outlet and a closed state where the atmosphere is not discharged from the outlet.

  As shown in FIG. 1, a control panel 13 is fixed to the floor surface 1, and a regulator 14, a regulator 15, a speed controller 16, a solenoid valve 17, a pressure sensor 18, and an air relay 19 are fixed to the control panel 13. Has been. Each of the regulator 14 and the regulator 15 has an inlet and an outlet. The air supplied from the inlet is adjusted to a constant pressure and discharged from the outlet. The respective inlets of the regulator 14 and the regulator 15 are connected to the outlet of the gate valve 12 through pipes. When the pump motor of the air pump 11 is operated with the gate valve 12 opened, the gate from the air pump 11 is connected to the gate. Atmospheric air is supplied to each of the inlet of the regulator 14 and the inlet of the regulator 15 through the valve 12, and detection air whose pressure is adjusted to a constant value is discharged from each of the outlet of the regulator 14 and the outlet of the regulator 15.

  As shown in FIG. 1, the speed controller 16 has an inlet, an outlet, and an orifice. The flow rate of air supplied from the inlet is adjusted to a constant value by the orifice, and discharged from the outlet. The inlet of the speed controller 16 is connected to the outlet of the regulator 14 via a pipe, and the speed controller 16 discharges the detected air at a constant flow rate when the detected air at a constant pressure is supplied from the regulator 14. The speed controller 16 corresponds to a flow valve. The solenoid valve 17 has an injection side inlet, an injection side outlet, a discharge side inlet, and a discharge side outlet. The inlet of the solenoid valve 17 is connected to the outlet of the speed controller 16 via a pipe. The injection side outlet of the air cylinder 9 is connected to the injection port of the air cylinder 9 through a pipe. The discharge port of the air cylinder 9 is connected to the discharge side inlet of the solenoid valve 17 via a pipe, and the discharge side outlet of the solenoid valve 17 is open to the atmosphere. The electromagnetic valve 17 corresponds to a control valve.

  The electromagnetic valve 17 uses an electromagnetic solenoid as a drive source, and is in an injection state when the electromagnetic solenoid is electrically on, and is in a discharge state when the electromagnetic solenoid is electrically off. The injection state is a state in which each of the injection side inlet and the injection side outlet is opened and each of the discharge side inlet and the discharge side outlet is closed. This injection state corresponds to the second state. In the injection state of the electromagnetic valve 17, the pressure chamber of the air cylinder 9 is closed from the atmosphere, and the detected air discharged from the outlet of the speed controller 16 is discharged. It is injected into the pressure chamber of the air cylinder 9. The discharge state is a state where each of the injection side inlet and the injection side outlet is closed and each of the discharge side inlet and the discharge side outlet is opened. This discharge state corresponds to the first state. When the electromagnetic valve 17 is discharged, the pressure chamber of the air cylinder 9 is opened to the atmosphere, and the pressure is passed through the electromagnetic valve 17 from the discharge port of the air cylinder 9. The detected air in the room is discharged into the atmosphere.

  As shown in FIG. 1, the pressure sensor 18 is connected to a pipe that connects the discharge side inlet of the electromagnetic valve 17 to the discharge port of the air cylinder 9. The pressure sensor 18 is applied with a pressure corresponding to the internal pressure of the pressure chamber of the air cylinder 9 when the electromagnetic valve 17 is infused, and outputs a pressure signal having a magnitude corresponding to the internal pressure of the pressure chamber. The pneumatic relay 19 is switched from an electrical OFF state to an ON state by the action of air pressure, and is returned from the ON state to the OFF state by the spring force of the return spring when the action of the air pressure is stopped. The air relay 19 is connected to the outlet of the push button valve 10 via a pipe, and air is supplied from the regulator 15 through the push button valve 10 when the push button valve 10 changes from the closed state to the open state. Thus, when the push button valve 10 is changed from the open state to the closed state, the supply of air is stopped to return to the off state. This static relay 19 corresponds to a switch.

  As shown in FIG. 2, a control circuit 20, a measurement start switch 21, a measurement stop switch 22, and a display 23 are fixed to the control panel 13. Each of the measurement start switch 21 and the measurement stop switch 22 changes in electrical state between an on state and an off state, and is turned on when an operating force is applied, and is turned off when the operating force disappears. It becomes a state. The control circuit 20 includes a CPU, a ROM, and a RAM. The electrical state of the measurement start switch 21, the electrical state of the measurement stop switch 22, the electrical state of the static relay 19, and the pressure sensor 18 Each of the pressure signals is detected. This control circuit 20 switches the electromagnetic solenoid of the electromagnetic valve 17 between the on state and the off state, and electrically operates the electromagnetic valve 17 between the injection state and the discharge state. The display 23 is visually recognizable by the operator, and when the control circuit 20 detects the pressure signal from the pressure sensor 18, the detection result of the pressure signal is displayed on the display 23 as the weight of the drum 8. . The control circuit 20 corresponds to a detection circuit.

  When the operator measures the weight of the drum can 8, a part of the drum can 8 is placed on the placement surface 3 of the detection table 2 in the operation state of the air pump 11 and the gate valve 12 is opened, and the placement surface 6 of the lever 4. Place the remaining portion of the drum 8 on the top. In this state, the control circuit 20 turns off the electromagnetic solenoid of the electromagnetic valve 17 so that the electromagnetic valve 17 is discharged, and the detected air from the speed controller 16 is blocked by the electromagnetic valve 17. When the solenoid valve 17 is in the exhausted state, the pressure chamber of the air cylinder 9 is at atmospheric pressure, the piston rod of the air cylinder 9 stops at the initial position, and the lever 4 stops at the reference position. The pushbutton valve 10 is in a closed state by resting at a short distance.

  FIG. 3 is a flowchart for explaining the weight measurement process of the control circuit 20. This weight measurement process is performed by the CPU of the control circuit 20 in accordance with a control program recorded in advance in the ROM, and the CPU determines whether or not the measurement start switch 21 is in an ON state in step S1. The measurement start switch 21 is operated by the operator while the drum can 8 is placed on the placement surface 3 of the detection table 2 and the placement surface 6 of the lever 4, and the measurement start switch 21 is operated. In step S1, the CPU determines that the measurement start switch 21 is in the on state, and proceeds to step S2.

  When the CPU proceeds to step S2, the electromagnetic solenoid of the electromagnetic valve 17 is switched from the off state to the on state. When the electromagnetic solenoid is on, the electromagnetic valve 17 is in an injecting state, and when the electromagnetic valve 17 is in an injecting state, detection air from the speed controller 16 is injected into the pressure chamber of the air cylinder 9. FIG. 4 shows temporal changes in the pressure signal from the pressure sensor 18, and before the internal pressure of the pressure chamber of the air cylinder 9 reaches a magnitude corresponding to the weight of the drum can 8, the piston rod rises. By being suppressed by weight, the pressure signal increases linearly with the passage of time with the atmospheric pressure as the reference value (0). This time change of the pressure signal is realized by the speed controller 16 adjusting the flow rate of the detected air from the regulator 14 to a constant value, and the internal pressure of the pressure chamber of the air cylinder 9 is discharged by the electromagnetic valve 17. When the state is switched to the injection state, the reference value (atmospheric pressure) rises in a straight line on the upper right with respect to the passage of time.

  When the CPU switches the electromagnetic solenoid to the ON state in step S2 of FIG. 3, the CPU sets an initial value (0) as the value of the timer T in the RAM in step S3. The value of the timer T is a value obtained by adding a constant value (0.1) in a timer interrupt process that starts every fixed time (0.1 seconds). The CPU initially sets the value of the timer T in step S3. If so, it is determined in step S4 whether or not the measurement stop switch 22 is on. If the operator operates the measurement stop switch 22 here, the CPU determines that the measurement stop switch 22 is in the on state, and ends the weight measurement process by switching the electromagnetic solenoid from the on state to the off state in step S5. .

  When the CPU determines in step S4 that the measurement stop switch 22 is in an off state, the CPU determines in step S6 whether or not the static relay 19 is in an on state. If it is determined that the static relay 19 is in the OFF state, the process proceeds to step S7, and the addition result of the value of the timer T is compared with the injection stop value Ta recorded in advance in the ROM. If it is determined that the addition result of the value of the timer T has not reached the injection stop value Ta, the process returns to step S4, and it is determined whether or not the measurement stop switch 22 is in the ON state.

  If the internal pressure of the pressure chamber of the air cylinder 9 reaches a magnitude corresponding to the weight of the drum 8 before the addition result of the value of the timer T reaches the injection stop value Ta, the drum can When the piston rod is lifted from the initial position against the weight of 8 and the piston rod is lifted from the initial position, the lever 4 is pushed counterclockwise from the reference position by pushing the operation surface 7 of the lever 4 from the bottom to the top. Rotate to. When the lever 4 is rotated counterclockwise from the reference position, the push button of the push button valve 10 is raised from the closed position to the open position, so that the push button valve 10 is switched from the closed state to the open state. When the pushbutton valve 10 is switched to the open state, air pressure acts on the static relay 19 from the regulator 15 through the pushbutton valve 10, and when air pressure acts on the static relay 19, the static relay 19 is activated. Switch from off to on. In this case, the CPU determines that the static relay 19 is in the ON state in step S6, and detects the pressure signal from the pressure sensor 18 in step S8. In step S9, the pressure signal detection result is displayed on the display 23 as the weight of the drum 8 and the process proceeds to step S11.

  When the CPU determines in step S7 that the result of addition of the value of timer T has reached the injection stop value Ta, the CPU displays a message indicating that measurement is impossible on the display 23 in step S10, and the electromagnetic solenoid is switched from the on state to the off state in step S5. The weight measurement process is finished by switching to. That is, when the operator places an excessively heavy drum can 8 on the placing surface 3 of the detection table 2 and the placing surface 6 of the lever 4, the internal pressure of the pressure chamber of the air cylinder 9 depends on the weight of the drum can 8. The limit time Ta elapses without reaching the size, and a message indicating that measurement is not possible is displayed on the display 23, thereby informing the operator that the weight of the drum 8 cannot be measured.

  When the CPU proceeds to step S11, the electromagnetic valve 17 is switched from the injection state to the discharge state by switching the electromagnetic solenoid from the on state to the off state. When the electromagnetic valve 17 is discharged, the pressure chamber of the air cylinder 9 is opened to the atmosphere through the electromagnetic valve 17 and the lever 4 is pushed by the weight of the drum can 8 to rotate clockwise from the current position. By rotating in the turning direction, the piston rod of the air cylinder 9 is lowered from the current position. When the lever 4 is lowered to return to the reference position, the lever 4 comes into contact with the stopper and stops at the reference position. When the lever 4 stops at the reference position, the piston rod descends at the initial position. Stop.

  When the CPU switches the electromagnetic solenoid to the OFF state in step S11, the CPU sets an initial value (0) as the value of timer T in step S12. In step S13, it is determined whether or not the addition result of the value of timer T has reached the discharge stop value Tb recorded in advance in the ROM. In step S14, it is determined whether or not the measurement stop switch 22 is in the ON state. To do. This discharge stop value Tb is set to a value necessary for the pressure chamber of the air cylinder 9 to return to atmospheric pressure after the electromagnetic solenoid is turned off in step S11. The result of addition of the value of the timer T If the operator operates the measurement stop switch 22 before reaching the discharge stop value Tb, the CPU determines that the measurement stop switch 22 is in the on state in step S14 and ends the weight measurement process.

  If the CPU determines that the addition result of the value of the timer T has reached the discharge stop value Tb without determining that the measurement stop switch 22 is in the ON state, the CPU switches the electromagnetic solenoid from the OFF state to the ON state in step S2. The next weight measurement process is started. That is, within a period from when the operator operates the measurement start switch 21 to when the measurement stop switch 22 is operated, an injection period for injecting detection air into the pressure chamber of the air cylinder 9 as shown in FIG. The discharge period for discharging the detection air from the pressure chamber of the air cylinder 9 alternately occurs, and the pressure signal from the pressure sensor 18 is detected each time the static relay 19 is turned on during the injection period, and the pressure signal is detected. Each time, the detection result of the pressure signal is displayed on the display 23 as the weight of the drum 8.

According to the said Example 1, there exists the following effect.
When the solenoid valve 17 is switched from the discharge state to the injection state, detection air starts to be injected into the cylinder tube of the air cylinder 9 from the air pump 11 through the regulator 14 and the speed controller 16, respectively. When the injection is started, the internal pressure of the cylinder tube rises from the atmospheric pressure in a linear shape that forms a straight line on the upper right with respect to the passage of time. When the internal pressure of the cylinder tube becomes a magnitude corresponding to the weight of the drum can 8, the lever 4 rotates counterclockwise from the reference position by the internal pressure of the cylinder tube, and the lever 4 rotates counterclockwise from the reference position. When rotating, the electrical state of the static relay 19 changes. When the electrical state of the static relay 19 changes, the control circuit 20 detects the pressure signal from the pressure sensor 18. The detection result of this pressure signal corresponds to the internal pressure of the cylinder tube when the lever 4 rotates counterclockwise from the reference position against the weight of the drum can 8, and the weight of the drum can 8 is detected as a pressure signal. Is done.

  As shown in FIG. 5, a plurality of detection bases 2 are fixed to the floor surface 1, and a lever 4, an air cylinder 9, and a push button valve 10 are attached to each of the plurality of detection bases 2. The respective inlets of the plurality of air cylinders 9 are connected to the inlet side outlet of the electromagnetic valve 17 via piping, and the respective outlets of the plurality of air cylinders 9 are connected to the outlet side inlet of the electromagnetic valve 17 via piping. When the solenoid valve 17 is discharged, the pressure chambers of the plurality of air cylinders 9 are opened to the atmosphere through the solenoid valve 17, and when the solenoid valve 17 is injected, the regulator 14 and the speed controller 16 are sequentially passed from the air pump 11. Then, detection air is injected into each pressure chamber of the plurality of air cylinders 9. Each inlet of the plurality of push button valves 10 is connected to the outlet of the regulator 15 through a pipe, and air is supplied from the regulator 15 to each inlet of the plurality of push button valves 10.

  As shown in FIG. 5, a plurality of air relays 19 are fixed to the control panel 13, and the control circuit 20 detects the electrical state of each of the plurality of air relays 19. Each of the plurality of pneumatic relays 19 is connected to the outlet of one push button valve 10 through a pipe, and the air pressure is passed from the regulator 15 through the one push button valve 10 when one push button valve 10 is opened. By acting, it will be in an on state, and in the closed state of one pushbutton valve 10, it will be in an off state without air pressure acting.

  When the operator measures the weight of each of the plurality of drum cans 8, a part of the drum can 8 is placed on each mounting surface 3 of the plurality of detection tables 2 in the operating state of the air pump 11 and the gate valve 12 being opened. The remaining portion of the drum can 8 is placed on the placement surface 6 of each of the plurality of levers 4. In this state, the control circuit 20 is in the discharge state of the electromagnetic valve 17, and the detected air from the speed controller 16 is blocked by the electromagnetic valve 17. In the exhausted state of the electromagnetic valve 17, the pressure chambers of the plurality of air cylinders 9 are at atmospheric pressure, and the piston rods of the plurality of air cylinders 9 are stopped at the initial positions, so that each of the plurality of levers 4 is Is stationary at the reference position, and each of the plurality of levers 4 is stationary at the reference position, whereby each of the plurality of push button valves 10 is closed.

  When the operator operates the measurement start switch 21 with each of the plurality of drum cans 8 placed on the placement surface 3 of the detection table 2 and the placement surface 6 of the lever 4, the control circuit 20 discharges the electromagnetic valve 17. Switch from state to injection state. In the injection state of the electromagnetic valve 17, detected air from the speed controller 16 is injected into the pressure chambers of the plurality of air cylinders 9, and the internal pressures of the pressure chambers of the plurality of air cylinders 9 correspond to the weight of the drum can 8. Before reaching the size, the rise of the piston rod is suppressed by the weight of the drum can 8, so that the pressure signal increases linearly with time from the reference value (0).

  When the weights of the plurality of drum cans 8 are different from each other, the piston rods of the plurality of air cylinders 9 rise from the initial position for each one, so that the plurality of levers 4 rotate counterclockwise from the reference position for each one. The plurality of push button valves 10 are opened one by one. For this reason, since the plurality of static relays 19 are turned on one by one, each time the vacuum relay 19 is turned on, the control circuit 20 detects the pressure signal from the pressure sensor 18, and the control circuit 20 Each time a signal is detected, the pressure signal detection result is displayed on the display 23 as the weight of the drum 8. Accordingly, the weight of each of the plurality of drums 8 is divided into one air pump 11, one gate valve 12, one regulator 14, one regulator 15, one speed controller 16, and one electromagnetic valve 17. Measurement can be performed with a simple configuration including one pressure sensor 18.

  In the second embodiment, an electromagnetic valve may be interposed in a pipe that connects each outlet of the plurality of pushbutton valves 10 to the inlet of the static relay 19. Each of the plurality of solenoid valves is switched between an open state and a closed state, and the control circuit 20 sets one of the plurality of solenoid valves according to the selection signal to an open state when a selection signal is given. Only the weight of one drum can 8 corresponding to the selection signal among the plurality of detection bases 2 is measured by setting one of the plurality of static relays 19 corresponding to the selection signal to an effective state in which air pressure can act. . In the case of this configuration, an operator that can be operated by the operator is provided on the control panel 13, and when the operator operates the operator, a selection signal corresponding to the operation content of the operator is output from the operator to the control circuit 20. It is preferable to do so.

  In each of the first and second embodiments, when the detection air is started to be injected into the cylinder tube of the air cylinder 9 by switching the solenoid valve 17 from the discharge state to the injection state, the internal pressure of the cylinder tube is changed from the atmospheric pressure. You may raise in the linear form used as the curve of the upper right with respect to progress of time.

  In each of the first and second embodiments, the control circuit 20 calculates the weight of the drum can 8 in units of weight according to the detection result of the pressure signal, and displays the calculation result in units of weight on the display unit 23. It is good also as a structure.

  In each of the above Examples 1 and 2, oil may be used as the fluid.

  4 is a lever, 8 is a drum can (measurement object), 9 is an air cylinder (cylinder), 11 is an air pump (fluid source), 14 is a regulator, 16 is a speed controller (flow valve), 17 is a solenoid valve (control valve), 18 is a pressure sensor, 19 is an aerodynamic relay (switch), and 20 is a control circuit (detection circuit).

Claims (1)

A fluid source for discharging fluid;
A regulator for adjusting the pressure of the fluid discharged from the fluid source;
A flow valve for adjusting the flow rate of the fluid regulated by the regulator;
A cylinder having a cylinder tube and a piston rod;
A control valve switched to each of the following 1A) first state and 2A) second state;
1A) First state in which the inside of the cylinder tube is opened 2A) In the state in which the inside of the cylinder tube is closed, fluid is injected from the fluid source into the cylinder tube through each of the regulator and the flow valve. In the second state in which pressure is applied to the piston rod, a measurement object for measuring the weight is placed, and levers exhibiting the following behaviors 1B) and 2B) respectively:
1B) The control valve stops at a fixed reference position in the first state. 2B) When the control valve is switched from the first state to the second state, the inside of the cylinder tube is measured. A switch that is pushed by the piston rod and moves from the reference position in response to the pressure corresponding to the weight of the object, and an electrical state that changes depending on whether or not the lever is in the reference position;
A pressure sensor that outputs a pressure signal corresponding to the pressure in the cylinder tube;
A detection circuit that detects a pressure signal from the pressure sensor when the electrical state of the switch changes due to the lever moving from the reference position;
The flow valve is disposed in the cylinder tube when the control valve is switched from the first state to the second state with the measurement object placed on the lever at the reference position of the lever. A weight measuring apparatus, wherein the flow rate of the fluid regulated by the regulator is adjusted so that the pressure rises linearly over time from a reference value.

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