JP2003300176A - Digital torque wrench, and setting failure detection method and model setting method for digital torque wrench - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide, promptly and exactly, a digital torque wrench capable of detecting contact failure such as broken soldering with a simple structure even if the contact failure occurs at a terminal for model setting. <P>SOLUTION: Model setting is made to a control part 26 of the digital torque wrench 10 with a combination of a low level and a high level from a model setting input part 28. The control part 26 includes a calculation part 26a for calculating the total of either of the low level or high level of a signal to be inputted, and a discriminating part 26b for discriminating the presence of connection failure between the control part 26 and the model setting input part 28 if parity of the calculated total is against the initially set parity, and output failure to a providing part 30 if the discriminating part 26b detects a change in the parity and discriminates it as connection failure. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital torque wrench, a method for detecting a setting failure of a digital torque wrench, and a method for setting a model of a digital torque wrench. The present invention relates to a digital torque wrench capable of surely detecting a terminal connection failure without displaying it as if it is a correct value, and an improvement in a setting failure detection method and a model setting method.

[0002]

2. Description of the Related Art Conventionally, joining of parts has been indispensable in assembling industrial products, and various joining methods have been used. In particular, in joining metal parts and the like, fastening parts such as bolts and nuts that can obtain a simple, reliable and strong joining force are used. When using bolts, nuts, etc., it is premised that they are properly tightened. Normally, bolts, nuts, etc. are used on the production line by automatic robots and workers using electric tools and the like. Then, in order to confirm whether or not this tightening work is being performed favorably at a predetermined torque, on the downstream side of the manufacturing line,
In many cases, an inspection process using a digital torque wrench is provided. The digital torque wrench measures the torque of bolts and nuts that have been tightened, and makes quality judgments based on whether or not the set torque has been reached.

Generally, the digital torque wrench has the same structure by changing the setting for the purpose of improving versatility and the like, and the setting torque can be selected according to the object of use. That is, when changing the model setting, as shown in FIG. 5, a common control unit (CPU) 100
A plurality of model setting terminals (for example, NO.
NO. Dip switches 102a-1 connected to 3)
By switching 02c (high level or low level) and changing the combination, the desired torque can be set. For example, as shown in FIG. 6, if only the dip switch 102a is set to “1: high level” and the dip switches 102b and 102c are set to “0: low level”, the rated torque is 90 N · m digital torque wrench. The model can be set to. If the dip switches 102a and 102b are set to "1: high level" and the dip switch 102c is set to "0: low level", the rated capacity is 180 Nm, and all the dip switches 102a to 102c are "1: high level". , It is possible to set the model as a digital torque wrench with a rated capacity of 360 N · m. As described above, when the DIP switches 102a to 102c are used, a maximum of eight types of model settings can be set by combining "1" and "0". In the above example, 3
Although it shows the case of setting by bit, it is usually CPU1
Since 00 has multiple terminals that can be used for model setting,
The number of bits used can be increased according to the number of set models.

[0004]

By the way, the CPU 10
The terminals formed at 0, including the model setting terminals, are generally fixed by soldering to the board and the DIP switches 102a to 102c (or lead wires from the dip switches 102a to 102c). However, this soldered portion may be peeled off due to poor soldering or application of external force after soldering. For example, "1,1,0" shown in FIG.
In a digital torque wrench with a rated capacity of 180 N · m, the “NO. 2 ”when the solder peeling occurs in the model setting terminal, the dip switches 102a to 10a
The setting of 2c becomes "1,0,0" and becomes the same as the digital torque wrench with the rated capacity of 90 N · m. In such a case, the digital torque wrench rated at 180 N · m where the solder has been peeled off will only display 50 N · m even when a torque of 100 N · m is actually applied. That is, there is a problem that an accurate torque inspection cannot be performed.

Particularly, the DIP switches 102a to 102
When the model is set by the combination of c, some torque is displayed even if solder peeling occurs. That is, there is a problem that an abnormal value is displayed as if it is a normal value, and an accurate tightening torque inspection cannot be performed. Further, since it is difficult to visually detect the solder peeling and the soldering failure, there is a problem that the detection of the solder peeling and the like is delayed and the accurate tightening torque inspection is hindered. If the setting is changed to the larger display side contrary to the above, "tightening OK" is determined even though the predetermined tightening torque is not obtained. There is a problem that it also leads to a decrease in reliability.

The present invention has been made in view of the above problems, and even if a contact failure such as solder peeling occurs at a model setting terminal, the contact failure can be found quickly, accurately and with a simple structure. An object of the present invention is to provide a digital torque wrench, a method for detecting a setting failure of the digital torque wrench, and a model setting method for the digital torque wrench.

[0007]

In order to achieve the above object, the present invention provides a model by combining a low level and a high level of a signal input to each of a plurality of input terminals formed in a control section. A digital torque wrench for setting, a calculation unit for calculating the total number of low level or high level signals input to the control unit, and the odd-even property of the total number calculated by the calculation unit is initially set. If it is against odd-evenness, a determination unit that determines that the input terminal is poorly connected, and if the determination unit determines that the input terminal is poorly connected, a presentation unit that presents a poor setting of the digital torque wrench, It is characterized by including.

In order to achieve the above-mentioned object, in the present invention according to the above-mentioned configuration, the model setting is such that the total number of either high level signals or low level signals is only an odd number or an even number. It is characterized in that it is set in the following combinations.

In order to achieve the above-mentioned object, the present invention is a method for detecting a setting failure of a digital torque wrench which sets a model by a combination of a low level signal and a high level signal input to a control unit. A step of calculating the total number of low-level signals or high-level signals of the signals input to the control unit, and if the odd-even property of the calculated total is contrary to the initially set odd-even property, a connection failure of the input terminal is caused. And a step of determining that there is.

In order to achieve the above object, the present invention is a model setting method of a digital torque wrench, which sets a model by a combination of a low level signal and a high level signal input to a control unit, The model setting is performed by a combination in which the total number of low level signals or high level signals input to the control unit is only odd numbers or even numbers.

For example, if the model is set in such a combination that the total number of high levels of signals input to the control unit is an odd number, and if a connection failure occurs at the input terminal for inputting high levels, the total number of high levels changes. To do. Here, it is extremely unlikely that a plurality of connection failures will occur simultaneously at exactly the same timing, and it can usually be considered that there is only one connection failure. In other words, the probability that even bad connections will occur at the same time is
Remarkably low. Therefore, when connection failure occurs, the total number of high level signals is always an even number. Similarly, when the model setting is performed with a combination in which the total number of high levels is even, if a connection failure occurs, it will always be an odd number.
This is the same for low level signals.

According to these configurations, it is possible to detect the occurrence of the connection failure of the input terminal quickly and reliably.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a digital torque wrench 10 according to this embodiment. The configuration of the digital torque wrench 10 is almost the same as that of a general digital torque wrench, and the torque sensor unit 12 is arranged on a main shaft connected to bolts, nuts and the like. This torque sensor unit 12
For example, when a Wheatstone bridge is configured with a predetermined resistance and a constant current is caused to flow through the Wheatstone bridge through the battery unit 14, the power supply unit 16, the applied voltage unit 18, etc., the torque acting on the torque sensor unit 12 is An output voltage proportional to is obtained. The voltage change is amplified by the amplification unit 20, filtered by the signal processing unit 22, and further processed by the A / D conversion unit 2.
In step 4, the analog signal is converted into a digital signal, and the converted signal is provided to the control unit 26 as a detection value.

In the control unit 26, the provided detection value is provided according to the setting made by the model setting input unit (a plurality of DIP switches in this embodiment) 28, that is, according to the set rated capacity. Is converted, and further compared with a threshold value determined according to the rated capacity to determine whether the bolt or nut to be inspected is properly tightened. The result of the quality judgment is the presentation unit 30.
The LED display color and the blinking operation are performed. For example, when the bolt or nut to be inspected is satisfactorily tightened with a torque equal to or greater than the threshold value, the green LED is turned on. On the contrary, if the tightening torque of the bolt or nut does not reach the threshold value, that is, if the tightening is poor,
The red LED is turned on and an alarm such as a beep sound is output to notify the operator of the odd or even tightening of the bolts and nuts. An operation unit 32 is connected to the control unit 26. The operation unit 32 is provided with a power switch, various function switches, and the like.

The characteristic feature of this embodiment is that the control unit 26
Is a calculation unit 26a that calculates the total number of low level signals or high level signals input from the model setting input unit 28, and if the calculated odd-evenness is contrary to the initially set odd-evenness, the control unit 26 and the model setting input unit 28 including a determination unit 26b that determines that there is a poor connection. The model setting input unit 28 includes a plurality of dip switches "high (high level signal)" and "high level signal". When setting the model of the rated capacity of the digital torque wrench 10 with the combination of "low (low level signal)", the total number of "high" or "low" of the DIP switch combination used for model setting is only odd or even Are set by the combination (default odd-evenness), and the control unit 2
The total number of “high” or “low” that 6 actually recognizes is
If it is determined that the odd-evenness of the initial setting is violated, it is determined that there is a poor connection between the model setting input unit 28 and the control unit 26, and the poor setting is presented to the user.

In the present embodiment, as an example, when the model setting input unit 28 uses six DIP switches and the total number of "low" combinations used for model setting is an odd number, that is, the initial setting. Shows the case where the oddness is odd. There are 64 combinations of "high" and "low" of 6 dip switches, but the total number of "low" is odd when the total number of "low" is "1". There are 6 ways, and the total number of "low" is "3"
There are 20 cases, and 6 when the total number of "laws" is "5"
There are 32 streets in total. That is, the digital torque wrench 10 of the present embodiment using 6 dip switches can be set up to 32 models at maximum.

In FIG. 2, in the control unit 26 of this embodiment,
The allocation of bit numbers to the DIP switches (No. 1 terminal to No. 6 terminal) in the model setting input unit 28 of the memory 1 and the memory 2 included in the calculation unit 26a for calculating the total number of "low" is shown. ing. Bit 0 to bit 3 exist in the memory 1, and the number of the DIP switch No.
1 terminal to No. Up to 4 terminals are connected. Similarly,
Bit 0 to bit 3 also exist in the memory 2, and the remaining dip switch No. 5 terminal and No. 6 terminals are connected.

FIG. 3 shows the "high: DIP switches (No. 1 terminal to No. 6 terminal) used in this embodiment.
A part of the combination of "1" and "Rho: 0" is shown. For example, when setting the rated capacity of "9Nm",
DIP switches (No. 1 terminal to No. 6 terminal)
It becomes "0, 1, 1, 1, 1, 1" in order. Further, for example, when the rated capacity is set to “850 N · m”, the dip switches (No. 1 terminal to No. 6 terminal) sequentially become “0, 0, 1, 1, 0, 1”. If necessary, a total of 32 combinations including an odd number of “row: 0” can be obtained by the same combination.
The model setting of 9 N · m or 180 N · m shown in FIG. 3 is an example, and it is optional as long as it is compatible with the DIP switch. Also, model setting based on the unit system that is normally used can be set according to the area of use. For example,
It may be “kgf · cm” or “lbf · in”. Also, even with the same torque, the expression is "Nm" or "kgf
The display may be switched to "cm" or "lbf in".

The flowchart of FIG. 4 shows a procedure for detecting a setting error in the digital torque wrench 10. That is, a low-level signal (low:
The procedure for calculating the total number of 0) and the procedure for determining the presence or absence of contact failure based on the result are shown. It should be noted that this flowchart may be activated at all times, may be activated when the power of the digital torque wrench 10 is turned on (at the beginning of use), or may be activated every predetermined time.

First, upon activation, the control unit 26 clears (0 resets) the memory used when the previous setting failure was detected (S100). Then, the calculation unit 26a of the control unit 26 determines that the No. It is determined whether the input from the 6 terminals is "low (0)" or "high (1)" (S10).
1). If it is "high", "0" is set to bit 1 of the memory 2 (S102). On the other hand, (S101)
In the case of "low", "1" is set to bit 1 of the memory 2 (S103), and the dip switch count memory included in the calculation unit 26a in the control unit 26 is incremented (+ 1UP) (S104).

Then, No. It is determined whether the input of the five terminals is "low (0)" or "high (1)" (S105). If it is "high", "0" is set to bit 0 of the memory 2 (S106). On the other hand, (S
In 105), if it is "low", "1" is set to bit 0 of the memory 2 (S107), and the dip switch count memory is incremented (+ 1UP) (S108).

Similarly, No. Bit 3 of memory 1, No. Memory 1 for 3 terminal inputs
Bit 2, No. Bit 1 of memory 1, No. The bit 0 of the memory 1 is set with respect to the input of the 1 terminal, and the dip switch count memory is incremented (+ 1UP) when it is "low" (S1
09) to (S124).

All DIP switches (No. 1 terminal ~
No. 6 terminal), when the determination is completed, the control unit 2
The determination unit 26b included in 6 determines whether the count number of the DIP switch count memory is an odd number or an even number (S125). If the count number is "odd", the determination unit sets an error flag "0" (S12).
6) If the count number is "even", the determination unit sets the error flag "1" (S127).

The control unit 26 determines whether the error flag is "0" or "1" by the determination unit 26b (S1).
28), if the error flag is “0”, that is,
When the total number of “low” recognized by the control unit 26 is “odd” and coincides with the initially set odd-even property (odd number), the setting of the digital torque wrench 10 is normal,
It is confirmed that the model setting input unit 28 and the control unit 26 are connected well, and that solder peeling or the like does not exist between them, and a normal display is performed via the presentation unit 30 (S12).
9). For this normal display, for example, a green LED provided in the presentation unit 30 is turned on. Of course, since it is normal and there is no need to call the user's attention, the lighting of the LED or the like may be omitted. That is, the normal display (S12
9) may be omitted.

On the other hand, when the error flag is "1", that is, when the total number of "low" recognized by the control unit 26 is "even", which is contrary to the initially set odd-even property (odd number), The setting of the digital torque wrench 10 is an odd number.
That is, it is confirmed that the connection between the model setting input unit 28 and the control unit 26 is poor, and that solder peeling or the like exists between them, and an error is displayed via the presentation unit 30 (S130). ). This error display is, for example, the presentation unit 30.
The red LED provided on the LED is turned on or a beep sound or the like is output via a speaker or the like to call the user's attention. Further, for example, processing such as turning off the power may be performed so as to prohibit the use of the digital torque wrench 10. The determination result of the determination unit 26b may be output as a separate report or transferred to another control device.

In this embodiment, since the connection state is monitored based on the odd-even change, an even number of connection defects occur at exactly the same timing, or the setting defect is intermittently detected. In this case, if an even number of connection failures occur during the detection interval, the odd-even change cannot be confirmed.
However, it is extremely unlikely that an even number of defective connections will occur at exactly the same timing or within a short period of time, which can be ignored in practical use, and there is no inconvenience.

In this embodiment, the odd-evenness is initially set to an odd number, but it may be set to an even number. That is, even if the model setting is performed with a combination of "0" and "1" in which the total number of rows is an even number, the same effect as in the present embodiment can be obtained. Further, even if the total number of highs is calculated and the odd-even property is determined, the same effect as that of the present embodiment can be obtained.

Further, in the present embodiment, an example in which 6 DIP switches are used to perform model setting with 6 bits has been shown, but the number of DIP switches used is arbitrary, and the model can be used according to the desired model to be set. Even if the number of bits is changed, the same effect as this embodiment can be obtained.

In this embodiment, the case where the digital torque wrench 10 is used for inspecting the tightening condition of the tightened screw has been described, but it is used when tightening to the predetermined torque value. Good.

[0031]

According to the present invention, even if a contact failure such as solder peeling occurs at a model setting terminal, the contact failure can be found quickly and accurately with a simple structure. It is possible to obtain a digital torque wrench setting failure detection method and a digital torque wrench model setting method.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a digital torque wrench according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating allocation of bit numbers to dip switches of a memory included in the control unit of the digital torque wrench according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a part of a combination of “high: 1” and “low: 0” of the dip switch used in the embodiment of the present invention.

FIG. 4 is a flowchart showing a procedure for detecting a setting failure of the digital torque wrench according to the embodiment of the present invention.

FIG. 5 is an external view of a control unit of the digital torque wrench.

FIG. 6 is an explanatory diagram showing a part of a combination of “high: 1” and “low: 0” of a conventional dip switch.

[Explanation of symbols]

10 digital torque wrench, 12 torque sensor,
14 battery section, 16 power supply section, 18 applied voltage section,
20 amplification section, 22 signal processing section, 24 A / D conversion section, 26 control section, 26a calculation section, 26b determination section,
28 model setting input section, 30 presentation section, 32 operation section.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Ono             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Toshitaka Kamikubo             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor ▲ Taka ▼ Akira Shima             2-12 Omorikita, Ota-ku, Tokyo Stocks             Company Tohnichi Works (72) Inventor Yasuhiro Yamamoto             2-12 Omorikita, Ota-ku, Tokyo Stocks             Company Tohnichi Works F term (reference) 3C038 CB06 CC08 EA01 EA03 EA06

Claims (4)

[Claims] 1. A digital torque wrench for setting a model by a combination of a low level and a high level of a signal input to each of a plurality of input terminals formed in the control unit, the low torque of the signal input to the control unit. A calculation unit that calculates the total number of either the level or the high level, and a determination unit that determines that the connection of the input terminal is poor if the odd-even property of the total number calculated by the calculation unit is contrary to the initially set odd-even property. And a presentation unit that presents a setting failure of the digital torque wrench when the determination unit determines that the connection of the input terminal is poor, the digital torque wrench. 2. The digital torque wrench according to claim 1, wherein the model setting is set by a combination in which the total number of either high level signals or low level signals is odd or even. This is a digital torque wrench. 3. A method for detecting a setting failure of a digital torque wrench that performs model setting by combining a low level signal and a high level signal input to a control unit, the low level signal or the high level signal of the signal input to the control unit. A step of calculating the total number of any one of the signals, and a step of determining that the input terminal has a poor connection when the odd number of the calculated total number is contrary to the initially set odd number, A method for detecting a setting error in a digital torque wrench. 4. A method for setting a model of a digital torque wrench, wherein a model is set by a combination of a low level signal and a high level signal input to a control unit, which is either a low level signal or a high level signal input to the control unit. A model setting method for a digital torque wrench, characterized in that the model setting is performed with a combination in which the total number of either one is only odd or even.