JPH08304210A - Calibrating method of dynamometer - Google Patents

Abstract

PURPOSE: To automatically and inexpensively calibrate a dynamometer. CONSTITUTION: A weight section 3 is connected to one arm 1a of a dynamometer 1 and a load cell 5 is connected to the other arm 1b of the dynamometer 1. A solenoid valve 4a or 4b is turned on in accordance with a command from a calibration control section 7 and the weight of the weight section 3 is changed through a hydraulic cylinder 3b. Here, whether or not the output of the load cell 5 falls within a prescribed range is decided and, when the output falls within the prescribed range, the solenoid valve 4a or 4b is turned off and the output of the load cell 5 is fetched as measurement data after a lapse of a prescribed period of time and a hydraulic mechanism is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamometer calibration method.

[0002]

2. Description of the Related Art FIG. 4 shows the configuration of a conventional dynamometer calibration device, where 1 is a dynamometer having horizontally extending arms 1a and 1b, and 3 is suspended from the arm 1a and weighs W ₁ to W. ₄ is a weighting part having a calibration weight 3a and a cylinder 3b, 4 is a three-way valve having an increasing solenoid valve 4a and a reducing solenoid valve 4b, 5
Is a load cell (load cell) suspended from the arm 1b,
Reference numeral 6 denotes a weight detection unit including a limit switch that detects which weight of the weighing weight 3a is weighted.
The output is digitally input to the calibration control unit 7 as a detection answer. Reference numeral 8 is a meter for displaying the output of the load cell 5, and 9 is a display unit connected to the calibration control unit 7 and having a keyboard 9a.

Next, the operation of the above configuration will be described with reference to the time chart of FIG. First, when an increase control signal is applied from the calibration control unit 7 to the increase solenoid valve 4a by digital output, the increase solenoid valve 4a is turned on as shown in FIG.
Three-way valve 4 and the oil passage 2 hydraulic pressure supplied to the cylinder 3b via, is discharged, the piston rises in the cylinder 3b, the arms 1a weight W ₁ is applied. The weight detection unit 6 detects this weight and sends the W ₁ detection answer of FIG. 5C to the calibration control unit 7. On the other hand, the load cell 5 detects the load, and the calibration control unit 7 receives the detection answer and reads the load data W ₁ from the load cell 5 as shown in FIG. 5 (g). Load data is input in analog quantity. Next, is turned on one after the other electromagnetic valve 4a for increasing in response to a control signal from the calibration control section 7, when raising the piston of the cylinder 3b, W ₂ to _W-4
Calibration weights 3a are sequentially weighted, and the detection answer is input from the weight detection unit 6 to the calibration control unit 7 as shown in FIGS. 5D to 5F, and the calibration control unit 7 loads the load data W ₁
+ W ₂ , W ₁ + W ₂ + W ₃ , and W ₁ + W ₂ + W ₃ + W ₄ are read one after another. Further, the calibration control unit 7 controls the reduction solenoid valve 4b as shown in FIG.
When turned on one after another as shown in (b), the detection answers are sent to the calibration control unit 7 one after another, and in response to this, the calibration control unit 7 receives the load data W ₁ + W ₂ + W ₃ , from the load cell 5.
W ₁ + W ₂ , W ₁ and zero are read one after another.

Next, in the calibration apparatus of FIG. 4, W _{1 to} W ₄
A case will be described in which there is no detection answer when weighting the calibration weight 3a. This is because the weight detection unit 6 is expensive when provided. In this case, the value of the meter 8 that displays the output of the load cell 5 is visually detected to know what kind of load is currently applied, and this value is read as load data.

FIG. 6 shows the configuration of another conventional dynamometer calibration device, in which the cylinder 3b, the three-way valve 4, the weight detection unit 6, the display unit 9 and the like are not provided. In this case, a person increases or decreases the calibration weight 3a and informs the calibration control unit 7 of what kind of weighting is currently performed, and the output of the load cell 5 at this time is read by the calibration control unit 7.

As another calibration method, in the case of FIG.
A human increases or decreases the calibration weight 3a, and the meter 8 at this time
Visually read the display as load data.

The total number of calibration weights 3a can be increased or decreased.

[0008]

As described above, in the conventional dynamometer calibration method, it is expensive to provide the weight detection unit 6 for detecting the weighted state of the calibration weight 3a. Also, if only the solenoid valve for increase 4a is turned on, the cylinder 3b
The piston rises and the load increases, and if only the reduction solenoid valve 4b is turned on, the load similarly decreases and the solenoid valves 4a and 4b
If both are turned off, the cylinder 3b stops and becomes stable. However, when the weight detection unit 6 is not provided,
The calibration control unit 7 could not know the weighted state, and therefore could not load the load data in a stable weighted state, and could not obtain reliable load data. For this reason, there is no choice but to rely on human visual inspection. Also, FIG.
Even in the case of the calibrating device of No. 3, it was not possible to carry out automatic calibration.

The present invention has been made to solve the above problems, and an object thereof is to obtain an inexpensive dynamometer calibration method capable of performing automatic calibration.

[0010]

A method for calibrating a dynamometer according to the present invention determines whether or not load data is within a predetermined range after turning on a solenoid valve of a fluid pressure mechanism for increasing or decreasing a load. The solenoid valve is turned off when it enters the predetermined range, and the load data is taken in as measurement data after a predetermined time.

[0011]

According to the present invention, after the solenoid valve of the fluid pressure mechanism for increasing / decreasing the load is turned on, it is determined whether the load data is within the predetermined range. Is turned off, and the load data is taken in as measurement data after the fluid pressure mechanism stabilizes after a predetermined time.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a dynamometer calibration device according to this embodiment, in which the weight detection unit 6 is removed from the device shown in FIG. 2 is a flow chart showing the control operation of the calibration control unit 7, and FIG. 3 is a time chart showing the operation of each unit. In FIG. 2, step S1 in FIG.
As shown in FIG. 3, the increasing solenoid valve 4a is turned on, and in step S2, the load data shown in FIG. In step S3, it is determined whether the read load data is within a predetermined range A (allowable range for expected load data (true value)). In this case, the calibration control unit 7 turns on the solenoid valves 4a and 4b so that the theoretical load (O, W
₁ , W ₁ + W ₂ , W ₁ + W ₂ + W ₃ , W ₁ + W ₂ + W ₃ + W ₄ ) is recognized (in this case, O to W ₁ ) and this logical weight W ₁ and the read load data are compared, and it is determined whether the difference is within a predetermined range. Alternatively, the judgment is made by comparing the read load data and all theoretical loads one after another. If it does not fall within the predetermined range, this operation is repeated, and if it falls within the predetermined range, the operation proceeds to the next step S4. t ₁ is the time to confirm that the predetermined range has been entered.

In step S4, the solenoid valve for increase 4a is turned off to stop the operation of the cylinder 3b, and in step S5, it is determined whether or not a predetermined time t _{2 has} elapsed. This operation is repeated until the time has passed, and when the time has passed, the process proceeds to step S6.
In step S6, the load data is taken in as measurement data, and an average value is calculated for each theoretical load. t ₃ is the load data acquisition time. In step S7, this average value is stored. In step S8, it is determined whether or not the number of times the measurement data has been fetched has reached a predetermined value. If not, the process returns to step S1 to turn on or off the solenoid valves 4a, 4b for increasing or decreasing the load for each theoretical load. Detect the data,
When the predetermined number of times is reached, the average result is recognized as the measured load data.

In the above embodiment, the solenoid valves 4a and 4b are used.
After turning on, when the load data is within the predetermined range, the solenoid valves 4a and 4b are turned on and the cylinder 3b is stopped,
The load data is taken in after the stabilization time t ₂ . Therefore, load data can be taken in in a stable state, and automatic calibration is possible without providing a weight detection unit. In addition, by measuring the time from when the solenoid valves 4a and 4b are turned on until the load data falls within a predetermined range, it is possible to determine whether the solenoid valves 4a and 4b are good or bad, the hydraulic system is good or bad, and the load cell 5 is good or bad. can do. In addition, in the above embodiment, the hydraulic mechanism is used for the weighting portion 3, but
Other fluid pressure mechanisms such as pneumatic mechanisms may be used.

[0015]

As described above, according to the present invention, after turning on the solenoid valve for changing the load, it is judged whether or not the load data is within the predetermined range. By turning off the fluid pressure mechanism to stop the load data after a predetermined time, the load data can be taken in stably without providing a weight detection unit, and automatic calibration is performed at low cost. be able to. Also, by measuring the time when the load data falls within a predetermined range after the solenoid valve is turned on, it is possible to determine the quality of the solenoid valve, the fluid pressure system, and the load meter.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a dynamometer calibration device that implements the method of the present invention.

FIG. 2 is a flowchart showing the method of the present invention.

FIG. 3 is a time chart showing the method of the present invention.

FIG. 4 is a configuration diagram of a conventional dynamometer calibration device.

FIG. 5 is a time chart showing the operation of the conventional device.

FIG. 6 is a configuration diagram of another conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dynamometer 1a, 1b ... Arm 3 ... Weighting part 3a ... Calibration weight 3b ... Cylinder 4 ... Three-way valve 4a, 4b ... Solenoid valve 5 ... Load cell 7 ... Calibration control part

Claims (1)

[Claims] 1. A dynamometer arm is connected to a weighting part that is driven by a fluid pressure mechanism to apply a variable load, and a load meter is connected to the dynamometer arm to control an electromagnetic valve of the fluid pressure mechanism. In the calibration method of the dynamometer that reads the load data from the load meter while changing the load, it is judged whether the load data is within the predetermined range after turning on the solenoid valve, and it is within the predetermined range. In some cases, the solenoid valve is turned off, and after a predetermined time, load data is taken in as measurement data.